Devices, methods, and systems for reshaping a heart valve annulus

Abstract

A delivery system, method, and related device for facilitating the delivery and deployment of a cardiac implant. Such delivery systems and methods include the use of a pair of magnetic catheters, including an anchor delivery catheter carrying an anchor, which can be stacked with or axially offset from the magnetic head. Such systems further include the use of a puncture guidewire advanceable through the magnetic head of the anchor delivery catheter to establish access to the heart cavity, the puncture guidewire attached to a bridge element such that continued advancement of the guidewire draws the bridge element attached to the first anchor across the heart cavity while the bridge element remains covered by the magnetically coupled catheter. The methods and devices herein also enable cutting and removal of the bridge element of a deployed cardiac implant.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 63 / 122,415, filed December 7, 2020. The disclosure of the prior application is considered part of the disclosure of this application and is incorporated by reference.

[0002] FIELD OF THE INVENTION The present invention relates generally to medical devices and procedures, and more particularly to systems, devices, and methods for delivering cardiac implants to treat heart diseases such as mitral valve regurgitation. [Background technology]

[0003] Background information Treatments for mitral valve regurgitation are wide-ranging and include both replacement valves and numerous procedures to facilitate valve repair and reshaping through the use of implants. Many such procedures rely on intravascular delivery of implants, which often utilize a system of multiple catheters that are repeatedly exchanged, often a complex and time-consuming process. To understand the issues and challenges associated with delivering and deploying implants within the human heart, it is useful to understand various aspects of the cardiac anatomy and conventional methods of deploying implants for the treatment of mitral valve regurgitation.

[0004] Healthy Heart Anatomy As can be seen in Figure 2A, the human heart is a bilateral (left and right) self-regulating pump whose parts work in unison to propel blood to all parts of the body. The right side of the heart receives poorly oxygenated ("venous") blood from the body through the superior and inferior vena cava and pumps it through the pulmonary artery to the lungs for oxygenation. The left side receives well-oxygenated ("arterial") blood from the lungs through the pulmonary veins and pumps it into the aorta for distribution to the body.

[0005] The heart has four chambers, two on each side: the right and left atria and the right and left ventricles. The atria are the receiving chambers that pump blood into the ventricles. The ventricles are the draining chambers. A wall composed of fibrous and muscular parts, called the interatrial septum, separates the right and left atria (see Figures 2B-2D). The anatomical landmark of the interatrial septum is the oval, fingerprint-sized depression called the fossa ovalis (FO), shown in Figure 2C. This is a remnant of the fetal foramen ovale and its valve; therefore, it lacks important structures such as valve structures, blood vessels, and conduction pathways. The synchronous pumping action of the left and right sides of the heart constitutes the cardiac cycle. This cycle begins with a period of ventricular relaxation, called ventricular diastole. This cycle ends with a period of ventricular contraction, called ventricular systole. The heart has four valves (see Figures 2B and 2C) that prevent blood from flowing in the wrong direction during the cardiac cycle, i.e., ensuring that blood does not flow backward from a ventricle to the corresponding atrium or from an artery to the corresponding ventricle. The valve between the left atrium and left ventricle is the mitral valve. The valve between the right atrium and right ventricle is the tricuspid valve. The pulmonary valve is at the opening of the pulmonary artery. The aortic valve is at the opening of the aorta.

[0006] At the beginning of ventricular diastole (ventricular filling), the aortic and pulmonary valves close to prevent backflow from the arteries into the ventricles.

[0007] Shortly thereafter, the tricuspid and mitral valves open to allow flow from the atria to the corresponding ventricles, as shown in Figure 2B. Shortly after ventricular systole (ventricular ejection) begins, the tricuspid and mitral valves close to prevent backflow from the ventricles to the corresponding atria, as shown in Figure 2C, and the aortic and pulmonary valves open to allow ejection of blood from the corresponding ventricles into the arteries.

[0008] Heart valves open and close primarily as a result of pressure differences. For example, the mitral valve opens and closes as a result of the pressure difference between the left atrium and the left ventricle. During ventricular diastole, as the ventricles relax, venous blood returns from the pulmonary veins to the left atrium, causing the pressure in the atria to exceed the pressure in the ventricles. This causes the mitral valve to open, allowing blood to enter the ventricles. As the ventricles contract during ventricular systole, the pressure in the ventricles rises above the pressure in the atria, closing the mitral valve.

[0009] As shown in Figures 2B-2C, the anterior (A) portion of the mitral annulus is in close contact with the non-coronary cusps of the aortic valve. The mitral annulus is also located near other important cardiac structures, such as the circumflex branch of the left coronary artery (which supplies the left atrium, variably the left ventricle, and in most cases, the sinoatrial node) and the atrioventricular node (which uses the sinoatrial node to regulate the cardiac cycle). Near the posterior (P) mitral annulus is the coronary sinus and its tributaries. These vessels gradually empty the areas of the heart supplied by the left coronary artery. The coronary sinus and its tributaries receive approximately 85% of coronary venous blood. As shown in Figure 2C, the coronary sinus drains posteriorly into the right atrium and anteriorly and inferiorly into the fossa ovalis. A tributary of the coronary sinus, called the great cardiac vein, runs parallel to most of the posterior mitral annulus and exits to the right of the posterior mitral annulus for an average distance of approximately 9.64 + / - 3.15 mm.

[0010] Characteristics and causes of mitral valve dysfunction When the left ventricle contracts after filling with blood from the left atrium, the ventricular wall moves inward, releasing some of the tension from the papillary muscles and chordae. Blood is forced beneath the surface of the mitral valve leaflets and ascends toward the annular plane of the mitral valve. As it progresses toward the annulus, the leading edges of the anterior and posterior leaflets come together to form a seal, closing the valve. In a healthy heart, coaptation of the leaflets occurs near the plane of the mitral annulus. Blood remains pressurized in the left ventricle until it is ejected into the aorta. Contraction of the papillary muscles occurs simultaneously with ventricular contraction and helps to tightly close the healthy valve leaflets at the peak systolic pressure exerted by the ventricle.

[0011] In a healthy heart (shown in Figures 2E-2F), the dimensions of the mitral valve annulus create an anatomical shape and tension that allow the leaflets to form a tight coaptation at peak systolic pressure. When the leaflets coapt on opposite medial (CM) and lateral (CL) sides of the annulus, they are called leaflet commissures. Valve malfunction can result from stretching and possibly tearing of the chordae tendineae (stretching). Strand tearing results in flail leaflets. Additionally, normally structured valves can malfunction due to enlargement or shape changes of the annulus. This condition is called annular dilation and generally results from myocardial insufficiency. Additionally, the valve may be defective at birth or due to acquired disease. Regardless of the cause, mitral valve dysfunction can occur when the leaflets do not coapt at peak systolic pressure, as shown in Figure 2G. In such cases, the coaptation line between the two valve leaflets is not tight during ventricular systole. As a result, unwanted backflow of blood from the left ventricle to the left atrium can occur, commonly known as mitral regurgitation. This has two important consequences. First, blood flowing back into the atrium can cause high atrial pressure, potentially reducing blood flow from the lungs to the left atrium. As blood returns to the pulmonary system, fluid leaks into the lungs, causing pulmonary edema. Second, the volume of blood directed toward the atrium reduces the volume of blood moving toward the aorta, lowering cardiac output. Excess blood in the atrium overfills the ventricles during each cardiac cycle, causing an increase in left ventricular circulating blood volume.

[0012] Mitral valve regurgitation is classified into two major types: i) organic or structural, and ii) functional. Organic mitral regurgitation results from structurally abnormal valve components that cause the valve leaflets to leak during systole. Functional mitral regurgitation results from annular dilation due to primary congestive heart failure, which is generally not surgically treatable and is not due to causes such as severe irreversible ischemia or primary valvular heart disease. Organic mitral regurgitation occurs when a breakdown in the seal occurs at the free anterior edge of the leaflet, causing the leaflet to flail due to rupture of the striate tissue or papillary muscles. Alternatively, if the leaflet tissue is redundant, the valve may prolapse beyond the level at which coaptation occurs higher in the atrium, and further prolapse opens the valve higher in the atrium during ventricular contraction. Functional mitral regurgitation results from dilation of the heart and mitral annulus secondary to heart failure, most often as a result of coronary artery disease or idiopathic dilated cardiomyopathy. When comparing a healthy annulus to an unhealthy annulus, the unhealthy annulus is dilated, specifically increasing the anterior-posterior distance along the minor axis (line PA). As a result, the shape and tension defined by the annulus become less oval and more rounded. This condition is called dilation. As the annulus is dilated, the shape and tension favorable for coaptation at peak contractile pressures progressively worsens.

[0013] Pretreatment method It has been reported that 25% of the 6 million Americans with congestive heart failure have some degree of functional mitral regurgitation. This accounts for 1.5 million people with functional mitral regurgitation. Treatment of mitral regurgitation can involve the use of diuretics and / or vasodilators to reduce the amount of blood returning to the left atrium. If medications do not stabilize the condition, an intra-aortic balloon counterpulsation device is used. In cases of chronic or acute mitral regurgitation, surgery to repair or replace the mitral valve is often necessary.

[0014] Interrupting the cycle of progressive functional mitral regurgitation has been shown to increase survival in surgical patients and actually increase the forward ejection fraction in many patients. The problem with surgical treatment is the significant damage done to these chronically ill patients with the high morbidity and mortality associated with surgical repair.

[0015] Currently, patient selection criteria for mitral valve surgery are highly selective, typically reserved for patients with normal ventricular function, generally good health, a life expectancy greater than 3–5 years, NYHA Class III or IV symptoms, and at least Grade 3 regurgitation. Patients who do not meet these requirements, typically elderly patients in poor health, are not suitable candidates for surgical procedures, especially open surgical procedures. These patients would benefit greatly from shorter, less invasive surgical procedures to improve valve function. However, these patients could benefit from further improvements in minimally invasive surgical procedures for deploying valve repair and restoration implants and systems that reduce the complexity of delivery systems and the duration of procedures, as well as from the consistency, reliability, and ease of use of these procedures.

[0016] Therefore, there is a need for further improvements that reduce the complexity of such delivery systems, and for improved delivery methods that shorten the duration of the procedure and improve the clinician's consistency, reliability, and ease of use in deploying cardiac implants for the treatment of mitral valve regurgitation. Summary of the Invention

[0017] The present invention provides systems, methods, and related devices for the delivery and deployment of cardiac implants to reshape the heart valve annulus for the treatment of heart conditions such as mitral regurgitation.

[0018] Thus, in one embodiment, the present invention provides a system for delivering a cardiac implant, the system including first and second magnetic catheters, the first catheter having a proximal end and a distal end and including: i) a first lumen extending through a length of the first catheter, ii) a first magnet disposed along a distal portion of the first catheter, the first magnet including a first magnetic pole and a second magnetic pole, and iii) a first guide channel disposed in the distal portion of the first catheter and extending along a first longitudinal axis, the first guide channel being coextensive with the first lumen and having a first side hole positioned proximally along the distal portion of the first catheter relative to the first magnetic pole. The second catheter has a proximal end and a distal end and includes: i) a second lumen extending through a length of the second catheter, ii) a second magnet disposed at the distal end of the second catheter, the second magnet including a third magnetic pole and a fourth magnetic pole, and iii) a second guide channel disposed at the distal end of the second catheter and extending along a second longitudinal axis, the second guide channel being coextensive with the second lumen and having a second side hole adjacent to the second magnet. In some embodiments, when the first magnet and the second magnet are magnetically coupled, the first side hole and the second side hole are aligned in a plane parallel to the first longitudinal axis and the second longitudinal axis, and the second side hole is oriented distally along the distal portion of the first catheter relative to the first side hole.

[0019] In another embodiment, the present invention provides a method of performing a surgical procedure in a subject using the system of the present invention, the method including: inserting a first catheter of the system of the present invention through a first vascular access site and advancing the first catheter to a first location within or adjacent to the subject's heart, inserting a second catheter of the system of the present invention through a second vascular access site and advancing the second catheter to a second location within or adjacent to the heart, wherein the first and second locations are separated by a cardiac tissue wall, positioning the first and second catheters such that the first and second magnets are magnetically coupled across the tissue wall, and penetrating the tissue wall with a penetrating member advanced through the first catheter, across the tissue wall, and through the second catheter while the first and second catheters are magnetically coupled, thereby performing the surgical procedure in the subject. In some aspects, the method further includes determining a depth of insertion of the first catheter and / or the second catheter via radiopaque markers disposed along the respective lengths of the catheters prior to magnetically coupling the first magnet and the second magnet. In some aspects, the method further includes, while the first magnet and the second magnet are magnetically coupled, advancing a posterior anchor and a bridge element coupled to the posterior anchor at a first end of the bridge element from the first vascular access site to a first location, advancing a second end of the bridge element through the penetrated tissue wall and into the second catheter, advancing an anterior anchor from the second vascular access site along the bridge element and deploying the anterior anchor at a third location within the heart, wherein the bridge element spans a cavity of the heart.

[0020] In another embodiment, the present invention provides a method of performing a surgical procedure in a subject using the system of the present invention, the method including: inserting a first catheter of the system of the present invention through a first vascular access site and advancing the first catheter to a first location within or adjacent to the subject's heart, inserting a second catheter of the system of the present invention through a second vascular access site and advancing the second catheter to a second location within or adjacent to the heart, wherein the first and second locations are separated by a cardiac tissue wall, positioning the first and second catheters such that the first and second magnets are magnetically coupled across the tissue wall, and penetrating the tissue wall with a penetrating member advanced through the first catheter or the second catheter and across the tissue wall while the first and second catheters are magnetically coupled, thereby performing the surgical procedure in the subject.

[0021] In yet another embodiment, the present invention provides a method of treating mitral valve regurgitation in a subject by reshaping a heart chamber in the subject, the method including: inserting a first catheter of a system of the present invention through a first vascular access site and advancing the first catheter to a first location within or adjacent to the subject's heart; inserting a second catheter of the system of the present invention through a second vascular access site and advancing the second catheter to a second location within or adjacent to the heart, the first and second locations being separated by a cardiac tissue wall; positioning the first and second catheters such that the first and second magnets are magnetically coupled across the tissue wall; penetrating the tissue wall with a penetrating member advanced through the first catheter, across the tissue wall, and through the second catheter while the first and second catheters are magnetically coupled; and advancing a posterior anchor and a bridge element coupled to the posterior anchor at a first end of the bridge element from a first vascular access site to a first location while the magnets are magnetically coupled, advancing a second end of the bridge element through the penetrated tissue wall and into a second catheter, advancing an anterior anchor from the second vascular access site along the bridge element to deploy the anterior anchor at a third location within the heart, wherein the bridge element spans a cavity of the heart, reshaping the cavity of the heart by shortening a length of the bridge element, and coupling the second end of the bridge element to the deployed anterior anchor while the cavity of the heart remains reshaped, thereby treating mitral valve regurgitation in a subject. In some embodiments, the method further includes determining a depth of insertion of the first catheter and / or the second catheter via radiopaque markers disposed along the respective lengths of the catheters prior to magnetically coupling the first magnet and the second magnet.

[0022] In another embodiment, the present invention provides a method of treating mitral valve regurgitation in a subject by reshaping a heart chamber in the subject, the method including: inserting a first catheter of a system of the present invention through a first vascular access site and advancing the first catheter to a first location within or adjacent to the subject's heart; inserting a second catheter of the system of the present invention through a second vascular access site and advancing the second catheter to a second location within or adjacent to the heart, the first and second locations being separated by a cardiac tissue wall; positioning the first and second catheters such that the first and second magnets are magnetically coupled across the tissue wall; penetrating the tissue wall with a penetrating member advanced through the first or second catheter and across the tissue wall while the first and second catheters are magnetically coupled; and advancing the first and second magnets to a second location within the heart. While the magnets are magnetically coupled, advancing the posterior anchor and bridge element to a first position, wherein a first end of the bridge element is coupled to the posterior anchor; advancing a second end of the bridge element through the penetrated tissue wall as the posterior anchor is advanced through the first catheter; advancing an anterior anchor along the bridge element to deploy the anterior anchor at a third position within the heart, wherein the bridge element spans a cavity of the heart; reshaping the cavity of the heart by shortening a length of the bridge element, and coupling the second end of the bridge element to the deployed anterior anchor while the cavity of the heart is reshaped so that it remains reshaped, thereby treating mitral valve regurgitation in a subject.

[0023] In another embodiment, the present invention provides a method for treating mitral valve regurgitation in a subject by reshaping a heart chamber in the subject, the method including inserting a first catheter of a system of the present invention through a first vascular access site and advancing the first catheter to a first location within or adjacent to the subject's heart, inserting a second catheter of the system of the present invention through a second vascular access site and advancing the second catheter to a second location within or adjacent to the heart, the first and second locations being separated by a cardiac tissue wall, positioning the first and second catheters such that the first and second magnets are magnetically coupled across the tissue wall, and advancing a penetration catheter through the second catheter and across the tissue wall while the first and second catheters are magnetically coupled. penetrating the tissue wall with the member; advancing the posterior anchor and bridge element to a first position while the first magnet and the second magnet are magnetically coupled, wherein a first end of the bridge element is coupled to the posterior anchor; advancing the anterior anchor along the bridge element to deploy the anterior anchor at a third position within the heart, wherein the bridge element spans a cavity of the heart; reshaping the cavity of the heart by shortening a length of the bridge element, and coupling a second end of the bridge element to the deployed anterior anchor while the cavity of the heart is reshaped, thereby treating mitral valve regurgitation in a subject.

[0024] In yet another embodiment, the present invention provides a catheter system for measuring the insertion depth of a catheter within an anatomical vessel. The catheter system includes an elongate overtube having a lumen, a proximal end, a distal end, and an expandable member disposed at the distal end of the catheter, a catheter slidably disposed within the lumen of the overtube, and a depth measurement mechanism. In various aspects, the catheter includes a proximal end, a distal end, and a handle disposed at the proximal end of the catheter. In various aspects, the depth measurement mechanism is slidably coupled to the handle at the proximal end of the mechanism and to the overtube at the distal end of the mechanism, the mechanism being configured to measure movement of the catheter along the lumen of the overtube when the distal end of the catheter is advanced distally relative to the distal end of the overtube when the expandable member is inflated. In some aspects, the catheter of the system is the first catheter of the present invention.

[0025] In another embodiment, the present invention provides a method for measuring insertion depth within an anatomical vessel. The method includes advancing a catheter system of the present invention into the anatomical vessel. The inflation member is then expanded such that the overtube remains stationary within the vessel. The method further includes advancing a distal end of the catheter distally relative to the distal end of the overtube and measuring, via a measurement mechanism, the distance the distal end of the catheter is advanced distally relative to the distal end of the overtube, thereby measuring the insertion depth of the catheter within the anatomical vessel.

[0026] In yet another embodiment, the present invention provides a method of treating mitral valve regurgitation in a subject by reshaping a heart chamber in the subject, the method including: inserting a catheter system of the present invention including an overtube through a first vascular access site and advancing the overtube and a first catheter of the system of the present invention along the vascular access; inflating an expandable member so that the overtube remains stationary at the vascular access; advancing the first catheter to a first location within or adjacent to the subject's heart, the first location being determined by measuring the depth of insertion via a measurement mechanism; inserting a second catheter of the system of the present invention through a second vascular access site and advancing the second catheter to a second location within or adjacent to the heart, the first and second locations being separated by a cardiac tissue wall; positioning the first and second catheters such that the first and second magnets are magnetically coupled across the tissue wall; penetrating the tissue wall with a penetrating member advanced through the first catheter or the second catheter across the tissue wall while the second catheter is magnetically coupled; advancing the posterior anchor and bridge element to a first position while the first magnet and the second magnet are magnetically coupled; advancing a second end of the bridge element through the penetrated tissue wall and into the second catheter as the posterior anchor is advanced through the first catheter; advancing an anterior anchor along the bridge element to deploy the anterior anchor at a third position within the heart, wherein the bridge element spans a cavity of the heart; reshaping the heart by shortening a length of the bridge element, and coupling the second end of the bridge element to the deployed anterior anchor while the cavity of the heart remains reshaped, thereby treating mitral valve regurgitation in a subject.

[0027] In yet another embodiment, the present invention provides a method of treating mitral valve regurgitation in a subject by reshaping a heart chamber in the subject, the method including: inserting a catheter system of the present invention including an overtube through a first vascular access site, advancing the overtube and first catheter of the present system along the vascular access, inflating an expandable member so that the overtube remains stationary at the vascular access, advancing the first catheter to a first location within or adjacent to the subject's heart, the first location being determined by measuring the depth of insertion via a measurement mechanism, inserting a second catheter of the present system through a second vascular access site and advancing the second catheter to a second location within or adjacent to the heart, the first and second locations being separated by a cardiac tissue wall, and magnetically coupling the first and second magnets across the tissue wall. positioning the catheters; penetrating the tissue wall with a penetrating member advanced through the first catheter or the second catheter across the tissue wall while the first and second catheters are magnetically coupled; advancing the posterior anchor and bridge element to a first position while the first magnet and the second magnet are magnetically coupled, wherein a first end of the bridge element is coupled to the posterior anchor; advancing the anterior anchor along the bridge element to deploy the anterior anchor at a third position within the heart, wherein the bridge element spans a cavity of the heart; reshaping the cavity of the heart by shortening a length of the bridge element, and coupling a second end of the bridge element to the deployed anterior anchor while the cavity of the heart remains reshaped, thereby treating mitral valve regurgitation in a subject. [The present invention 1001] a) having a proximal end and a distal end; i) a first lumen extending through the length of the first catheter; ii) a first magnet disposed along a distal portion of the first catheter, the first magnet including a first magnetic pole and a second magnetic pole; iii) a first guide channel disposed in the distal portion of the first catheter and extending along a first longitudinal axis, the first guide channel being coextensive with the first lumen and having a first side hole positioned proximally along the distal portion of the first catheter relative to the first magnetic pole; the first catheter comprising: b) having a proximal end and a distal end; i) a second lumen extending through the length of the second catheter; ii) a second magnet disposed at the distal end of the second catheter, the second magnet including a third pole and a fourth pole; iii) a second guide channel disposed at the distal end of the second catheter and extending along a second longitudinal axis, the second guide channel being coextensive with the second lumen and having a second side hole adjacent to the second magnet; the second catheter comprising Including, When the first magnet and the second magnet are magnetically coupled, the first side hole and the second side hole are aligned in a plane parallel to the first longitudinal axis and the second longitudinal axis, and the second side hole is oriented distally along the distal portion of the first catheter relative to the first side hole. A system for delivering a cardiac implant. [The present invention 1002] The system of the present invention 1001, wherein when the first magnet and the second magnet are magnetically coupled, the first side hole and the second side hole are at an angle of approximately 90 degrees to each other. [The present invention 1003] The system of the present invention 1001, wherein when the first magnet and the second magnet are magnetically coupled, the distal portion of the first catheter and the distal end of the second catheter are at an angle of approximately 90 degrees relative to each other. [The present invention 1004] The system of the present invention 1001, wherein the first magnetic pole and the second magnetic pole are disposed perpendicular to the first longitudinal axis. [The present invention 1005] The system of the present invention 1001, wherein the third magnetic pole and the fourth magnetic pole are arranged parallel to the second longitudinal axis, and the third pole is distal to the fourth pole along the distal end of the second catheter. [The present invention 1006] The system of the present invention 1001, wherein when the first magnet and the second magnet are magnetically coupled, the first magnetic pole and the third magnetic pole are adjacent to each other. [The present invention 1007] The second magnet is an arcuate or angled surface oriented toward and defining a surface of the second guide channel; a curved recess having The surface of the second guide channel is When the first magnet and the second magnet are magnetically coupled, they guide a guide wire extending from the first guide channel through the second guide channel. It is configured as follows: The system of the present invention 1001. [The present invention 1008] The system of claim 1007, wherein the curved recess extends from a distal portion of the second magnet to a proximal portion of the second magnet. [The present invention 1009] a penetrating member or guidewire advanceable through the first and second guide channels via the first and second side holes when the first and second magnets are magnetically coupled; 10. The system of claim 10, further comprising: said penetrating member or guidewire having a sharpened distal end to facilitate penetration of tissue. [The present invention 1010] The system of the present invention 1001 further comprising a radiopaque marker disposed at the distal end of the first catheter or the second catheter. [The present invention 1011] 1009. The system of claim 10, wherein the radiopaque marker is disposed at the distal end of the first catheter, distal to the first magnet. [The present invention 1012] 10. The system of claim 10, wherein the first catheter comprises radiopaque markers disposed along the length of the first catheter for determining depth of insertion. [The present invention 1013] 1001. The system of claim 10, wherein the second catheter comprises radiopaque markers disposed along the length of the second catheter for determining depth of insertion. [The present invention 1014] The system of the present invention 1001, wherein the first catheter includes one or more radiopaque markers arranged along the distal portion of the first catheter, the one or more radiopaque markers being asymmetrically positioned about the longitudinal axis of the first guide channel to facilitate alignment of the rotational orientation of the first catheter relative to the second catheter prior to magnetic coupling. [The present invention 1015] The system of the present invention 1014, wherein the one or more radiopaque markers comprise a first and a second marker, the first marker being disposed on the same side of the first catheter as the first side hole and being separate from the second marker under X-ray fluoroscopy. [The present invention 1016] 1. A method of performing a surgical procedure in a subject, comprising: inserting the first catheter of any of the systems of inventions 1001 to 1015 through a first vascular access site and advancing the first catheter to a first location within or adjacent to the heart of the subject; inserting the second catheter of any one of the systems of inventions 1001 to 1015 through a second vascular access site and advancing the second catheter to a second location within or adjacent to the heart, wherein the first and second locations are separated by a tissue wall of the heart; positioning the first catheter and the second catheter such that the first magnet and the second magnet are magnetically coupled across the tissue wall; penetrating the tissue wall with a penetrating member advanced through the first catheter or the second catheter and across the tissue wall while the first and second catheters are magnetically coupled, thereby performing a surgical procedure on the subject; A method comprising: [The present invention 1017] The method of claim 1016, further comprising determining the depth of insertion of the first catheter via the radiopaque markers disposed along the length of the first catheter prior to magnetic coupling of the first magnet and the second magnet. [The present invention 1018] The method of claim 1016, further comprising determining the depth of insertion of the second catheter via the radiopaque markers disposed along the length of the second catheter prior to magnetic coupling of the first magnet and the second magnet. [The present invention 1019] The method of claim 1016, further comprising determining proper alignment of the first catheter and the second catheter via the one or more radiopaque markers disposed along the distal portion of the first catheter before the first magnet and the second magnet are magnetically coupled. [The present invention 1020] advancing a posterior anchor and the bridge element coupled to the posterior anchor at a first end of the bridge element from the first vascular access site to the first location while the first magnet and second magnet are magnetically coupled; advancing a second end of the bridge element through the penetrated tissue wall and into the second catheter; advancing an anterior anchor along the bridging element from the second vascular access site and deploying the anterior anchor at a third location within the heart, the bridging element spanning a cavity of the heart; The method of the present invention 1016 further comprising: [The present invention 1021] The posterior anchor is an elongate member having a strain relief portion that flexes during advancement to the first position to accommodate curvature of the vasculature and to avoid crimping of the posterior anchor; The method of the present invention 1020. [The present invention 1022] 1021. The method of claim 1020, further comprising reshaping the chamber of the heart by shortening the length of the bridging element. [The present invention 1023] 1023. The method of claim 1022, wherein shortening the length of the bridge element comprises advancing the second end of the bridge element through or across the deployed anterior anchor. [The present invention 1024] The method of claim 1022, further comprising coupling the bridging element to the deployed anterior anchor while the cavity of the heart is being reshaped, so that the cavity of the heart remains reshaped. [The present invention 1025] 1025. The method of claim 1024, wherein the bridge element is attached to the posterior anchor at the first end of the bridge element and to the anterior anchor at the second end of the bridge element. [The present invention 1026] The method of claim 1020, wherein said chamber of said heart is the left atrium. [The present invention 1027] The method of claim 1016, wherein said subject has or is at risk for mitral valve regurgitation. [The present invention 1028] The method of claim 1027, wherein the subject has congestive heart failure. [The present invention 1029] 1. A method of treating mitral valve regurgitation in a subject by reshaping a heart chamber of the subject, comprising: inserting the first catheter of any of the systems of inventions 1001 to 1015 through a first vascular access site and advancing the first catheter to a first location within or adjacent to the heart of the subject; inserting the second catheter of any one of the systems of inventions 1001 to 1015 through a second vascular access site and advancing the second catheter to a second location within or adjacent to the heart, wherein the first and second locations are separated by a tissue wall of the heart; positioning the first catheter and the second catheter such that the first magnet and the second magnet are magnetically coupled across the tissue wall; penetrating the tissue wall with a penetrating member advanced through the first catheter or the second catheter and across the tissue wall while the first and second catheters are magnetically coupled; advancing a posterior anchor and the bridge element coupled to the posterior anchor at a first end of the bridge element to the first position while the first magnet and second magnet are magnetically coupled; advancing the second end of the bridging element through the penetrated tissue wall as the posterior anchor is advanced through the first catheter; advancing an anterior anchor along the bridge element and deploying the anterior anchor at a third location within the heart, the bridge element spanning a cavity of the heart; reshaping the heart chamber by shortening a length of the bridge element, and coupling the second end of the bridge element to the deployed anterior anchor while the heart chamber is reshaping so that the heart chamber remains reshaped, thereby treating mitral valve regurgitation in the subject. A method comprising: [The present invention 1030] 1029. The method of claim 1029, wherein shortening the length of the bridge element comprises advancing the second end of the bridge element through or across the deployed anterior anchor. [The present invention 1031] The method of claim 1029, further comprising determining the depth of insertion of the first catheter via the radiopaque markers disposed along the length of the first catheter prior to magnetic coupling of the first magnet and the second magnet. [The present invention 1032] The method of claim 1029, further comprising determining the depth of insertion of the second catheter via the radiopaque markers disposed along the length of the second catheter prior to magnetic coupling of the first magnet and the second magnet. [The present invention 1033] The method of claim 1029, further comprising determining proper alignment of the first catheter and the second catheter via the one or more radiopaque markers disposed along the distal portion of the first catheter before the first magnet and the second magnet are magnetically coupled. [The present invention 1034] 1029. The method of claim 1029, wherein said chamber of said heart is the left atrium. [This invention 1035] a) an elongate overtube having a lumen, a proximal end, a distal end, and an expandable member disposed at the distal end; b) a catheter slidably disposed within the lumen, the catheter having a proximal end, a distal end, and a handle disposed at the proximal end of the catheter; c) a depth measurement mechanism slidably coupled to the handle at a proximal end thereof and coupled to the overtube at a distal end thereof, the mechanism configured to measure movement of the catheter along the lumen of the overtube when the distal end of the catheter is advanced distally relative to the distal end of the overtube when the expandable member is inflated; and A catheter system comprising: [The present invention 1036] The catheter system of the present invention 1035, wherein the expandable member is an expandable balloon or an expandable stent. [This invention 1037] The mechanism comprises: an elongate shaft slidable within a bond disposed on the handle to translate movement of the catheter relative to the overtube when the catheter is advanced distally or proximally within the lumen of the overtube. The catheter system of the present invention 1035 comprises: [The present invention 1038] The catheter system of present invention 1035, wherein the catheter is the first catheter of any one of present inventions 1001 to 1015. [This invention 1039] 1. A method for measuring insertion depth within an anatomical vessel, comprising: Advancing any one of the catheter systems 1035 to 1038 into the anatomical vessel; expanding an inflation member such that the overtube remains stationary within the vessel; advancing the distal end of the catheter distally relative to the distal end of the overtube; measuring via a measurement mechanism the distance the distal end of the catheter advances distally relative to the distal end of the overtube, thereby measuring the insertion depth of the catheter within the anatomical vessel; A method comprising: [The present invention 1040] 1039. The method of claim 1039, wherein said anatomical vessel is the great cardiac vein. [This invention 1041] 1. A method of treating mitral valve regurgitation in a subject by reshaping a heart chamber of the subject, comprising: inserting a catheter system of the present invention 1038 through a first vascular access site and advancing the overtube and first catheter along the vascular access; inflating an expandable member such that the overtube remains stationary in the vascular access; advancing the first catheter to a first location within or adjacent to the subject's heart, the first location being determined by measuring a depth of insertion via a measurement mechanism; inserting the second catheter of any one of the systems of inventions 1001 to 1015 through a second vascular access site and advancing the second catheter to a second location within or adjacent to the heart, the first location and the second location being separated by a tissue wall of the heart; positioning the first catheter and the second catheter such that the first magnet and the second magnet are magnetically coupled across the tissue wall; penetrating the tissue wall with a penetrating member advanced through the first catheter or the second catheter across the tissue wall while the first and second catheters are magnetically coupled; advancing a posterior anchor and the bridge element coupled to the posterior anchor at a first end of the bridge element to the first position while the first magnet and second magnet are magnetically coupled; advancing an anterior anchor along the bridge element and deploying the anterior anchor at a third location within the heart, the bridge element spanning a cavity of the heart; reshaping the heart chamber by shortening a length of the bridge element, and coupling the second end of the bridge element to the deployed anterior anchor while the heart chamber is reshaping so that the heart chamber remains reshaped, thereby treating mitral valve regurgitation in the subject. A method comprising: [Brief explanation of the drawings]

[0028] [Figure 1] 1 shows an overview of a catheter system for intravascular delivery of a cardiac implant for the treatment of mitral valve regurgitation, according to an embodiment of the present invention. [Figure 2A] 1 is an anatomical anterior view of the human heart with portions separated and cross-sectioned to view the cardiac cavities and adjacent structures. [Figure 2B] Anatomical superior view of a cross section of the human heart showing the tricuspid valve in the right atrium, the mitral valve in the left atrium, and the aortic valve in between; during ventricular diastole (ventricular filling) of the cardiac cycle, the tricuspid and mitral valves are open, and the aortic and pulmonary valves are closed. [Figure 2C] FIG. 2B is an anatomical superior view of a cross section of the human heart shown in FIG. 2B, in which during ventricular systole (ventricular ejection) of the cardiac cycle, the tricuspid and mitral valves are closed and the aortic and pulmonary valves are open. [Figure 2D]FIG. 1 is an anatomical anterior perspective view of the left and right atria, partially cross-sectionally shown to show the interior of the heart chambers and associated structures, such as the fossa ovalis, coronary veins, and great cardiac vein. [Figure 2E] FIG. 1 is a superior view of a healthy mitral valve with the leaflets closed and coapted at peak systolic pressure during ventricular contraction. [Figure 2F] FIG. 2E is an anatomical superior view of a cross section of a human heart with the normal mitral valve shown in FIG. 2E closed during ventricular systole (ventricular ejection) of the cardiac cycle. [Figure 2G] Superior view of a dysfunctional mitral valve, where the leaflets fail to coapt during peak systolic pressure during ventricular systole, leading to mitral regurgitation. [Figure 3A] FIG. 1 is an anatomical anterior perspective view of the left and right atria, partially sectioned to show the presence of an implant system having an interatrial bridging element spanning the mitral valve annulus between a posterior anchor positioned in the great cardiac vein and an anterior anchor in the atrial septum, suitable for delivery with the catheter system and delivery method of the present invention. [Figure 3B] FIG. 1 is an anatomical anterior perspective view of the left and right atria, partially sectioned to show the presence of an implant system having an interatrial bridging element spanning the mitral valve annulus between a posterior anchor positioned in the great cardiac vein and an anterior anchor in the atrial septum, suitable for delivery with the catheter system and delivery method of the present invention. [Figure 4A] FIG. 10 is a detailed view showing an anterior anchor deployed in the fossa ovalis of the atrial septum and a posterior anchor deployed in the great cardiac vein. [Figure 4B] FIG. 10 is a detailed view showing an anterior anchor deployed in the fossa ovalis of the atrial septum and a posterior anchor deployed in the great cardiac vein. [Figure 5A] FIG. 10 shows a detailed view of an exemplary anterior anchor of an implant suitable for anchoring in the fossa ovalis of the atrial septum. [Figure 5B] FIG. 10 shows a detailed view of an exemplary anterior anchor of an implant suitable for anchoring in the fossa ovalis of the atrial septum. [Figure 6A]10 illustrates an exemplary locking bridge stop for locking a bridge element relative to an anterior anchor of an implant. [Figure 6B] 10 illustrates an exemplary locking bridge stop for locking a bridge element relative to an anterior anchor of an implant. [Figure 7] Figures 7A and 7B show alternative cardiac implants suitable for intravascular delivery according to embodiments of the present invention. [Figure 8] 8A and 8B show alternative examples of posterior anchors attached to bridge elements for implants suitable for intravascular delivery, according to embodiments of the present invention. [Figure 9] 9A and 9B show alternative examples of a posterior anchor of a cardiac implant suitable for intravascular delivery according to embodiments of the present invention. [Figure 10] Figure 10A illustrates various components and steps for deploying an implant system with a catheter-based delivery system. Figure 10B illustrates various components and steps for deploying an implant system with a catheter-based delivery system. [Figure 11A] 1 illustrates various components and steps for deploying an implant system with a catheter-based delivery system. [Figure 11B] 1 illustrates various components and steps for deploying an implant system with a catheter-based delivery system. [Figure 11C] 1 illustrates various components and steps for deploying an implant system with a catheter-based delivery system. [Figure 12A] 1 illustrates the various components and steps of deploying an implant system with a conventional catheter-based delivery system. [Figure 12B]1 illustrates the various components and steps of deploying an implant system with a conventional catheter-based delivery system. [Figure 12C] 1 illustrates the various components and steps of deploying an implant system with a conventional catheter-based delivery system. [Figure 12D] 1 illustrates the various components and steps of deploying an implant system with a conventional catheter-based delivery system. [Figure 13] 10 illustrates a catheter-based delivery system for deployment of an implant system in which a bridge element attached to an anchor is delivered from a first vascular access point to a second vascular access point while the first and second catheters are magnetically coupled, according to an embodiment of the invention. [Figure 14A] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 14B] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 14C] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 14D] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 15A] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 15B] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 15C] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 15D] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 16A]1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 16B] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 16C] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 16D] 1 illustrates steps in the delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 17] 1 illustrates an example catheter system for delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 18] 1 illustrates an example of a catheter system for delivery and deployment of an implant system for treating mitral valve regurgitation according to an aspect of the present invention. [Figure 19] 1 illustrates an example catheter system for delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 20] 1 illustrates an example catheter system for delivery and deployment of an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 21] 1 illustrates an example of a catheter system for delivery and deployment of an implant system for treating mitral valve regurgitation according to an aspect of the present invention. [Figure 22A] 10 illustrates exemplary radiopaque markers that facilitate rotational alignment between delivery catheters of the system, according to aspects of the present invention. [Figure 22B] 22B shows an image of fluoroscopic visualization of the radiopaque marker shown in FIG. 22A. [Figure 23] 1 illustrates a method of delivering and deploying an implant system for the treatment of mitral valve regurgitation, according to an aspect of the present invention. [Figure 24]Figures 24A, 24B, and 24C show steps in cutting bridge elements of an implant with a bridge-cutting catheter according to an embodiment of the invention. [Figure 25] 1 illustrates a bridge cutting catheter with a suture grip, according to an aspect of the present invention. [Figure 26] Figures 26A and 26B show steps for cutting and removing bridge elements of an implant with a bridge-cutting catheter with suture grips according to an embodiment of the invention. [Figure 27] 1 illustrates a catheter-based delivery system for deployment of an implant system in which first and second catheters are magnetically coupled at their respective distal ends, according to an embodiment of the present invention. [Figure 28] 28 shows a perspective view of the distal end of the catheter of FIG. 27, in accordance with an embodiment of the present invention. [Figure 29] 29 shows a cross-sectional view of the distal end of the catheter of FIG. 28, in accordance with an embodiment of the present invention. [Figure 30] 1 illustrates a catheter of a catheter-based delivery system for deployment of an implant system, where the catheter includes radiopaque markers disposed along the length of the catheter for determining insertion depth, according to an aspect of the present invention. [Figure 31] 1 shows a catheter system according to an embodiment of the present invention, the proximal end of the catheter system including the overtube and handle portion of the catheter of the present invention is shown. [Figure 32] 31 shows a catheter system according to an embodiment of the present invention.The distal end of the catheter system shown in FIG. 31 is shown, including a portion of the overtube and the distal end of the catheter of the present invention. [Figure 33]1A-1C illustrate different positions on the heart for measuring the insertion depth of the catheter of the present invention. [Figure 34] 1 illustrates a catheter system of the present invention for measuring depth of insertion, according to an aspect of the present invention, the catheter system is shown with the inflation member expanded and the measurement mechanism at zero depth of insertion. [Figure 35] FIG. 35 shows the catheter system illustrated in FIG. 34, where the inflation member is expanded and the resulting insertion depth of the catheter distally advanced within the overtube is measured via the measurement mechanism. [Figure 36] 1 shows a magnetic catheter system of the present invention being used to advance a penetrating member, such as a crossing wire, from the left atrium into the GCV. [Figure 37] 10 shows the portion of the procedure in which a penetrating member, e.g., a crossing wire, is advanced from the left atrium into the GCV and a posterior anchor is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention. [Figure 38] 10 shows the portion of the procedure in which a penetrating member, e.g., a crossing wire, is advanced from the left atrium into the GCV and a posterior anchor is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention. [Figure 39] 10 shows the portion of the procedure in which a penetrating member, e.g., a crossing wire, is advanced from the left atrium into the GCV and a posterior anchor is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention. [Figure 40] 10 shows the portion of the procedure in which a penetrating member, e.g., a crossing wire, is advanced from the left atrium into the GCV and a posterior anchor is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention. [Figure 41] 10 shows the portion of the procedure in which a penetrating member, e.g., a crossing wire, is advanced from the left atrium into the GCV and a posterior anchor is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention. [Figure 42] 10 shows the portion of the procedure in which a penetrating member, e.g., a crossing wire, is advanced from the left atrium into the GCV and a posterior anchor is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention. [Figure 43]10 shows the portion of the procedure in which a penetrating member, e.g., a crossing wire, is advanced from the left atrium into the GCV and a posterior anchor is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention. [Figure 44] 10 shows the portion of the procedure in which a penetrating member, e.g., a crossing wire, is advanced from the left atrium into the GCV and a posterior anchor is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention. [Figure 45] 10 shows the portion of the procedure in which a penetrating member, e.g., a crossing wire, is advanced from the left atrium into the GCV and a posterior anchor is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention. [Figure 46] FIG. 10 shows the portion of the procedure in which a penetrating member (e.g., a pusher shaft) having a screw tip attached to a suture bridge is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention, and the screw tip and suture bridge are attached to a posterior anchor positioned in the GCV. [Figure 47] FIG. 10 shows the portion of the procedure in which a penetrating member (e.g., a pusher shaft) having a screw tip attached to a suture bridge is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention, and the screw tip and suture bridge are attached to a posterior anchor positioned in the GCV. [Figure 48] FIG. 10 shows the portion of the procedure in which a penetrating member (e.g., a pusher shaft) having a screw tip attached to a suture bridge is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention, and the screw tip and suture bridge are attached to a posterior anchor positioned in the GCV. DETAILED DESCRIPTION OF THE INVENTION

[0029] Detailed Description of the Invention While the disclosure in the specification is detailed and accurate to enable those skilled in the art to practice the invention, the physical embodiments disclosed herein are merely illustrative of the invention as it may be embodied in other specific structures. While preferred embodiments are described, the details may be changed without departing from the invention as defined by the claims.

[0030] FIG. 1 illustrates an exemplary embodiment of a catheter-based delivery system according to aspects of the present invention. The delivery system utilizes a pair of magnetic catheters advanced from separate vascular access points and magnetically coupled across intracardiac tissue. The pair of catheters includes a GCV anchor delivery catheter 50 introduced through the jugular vein and advanced along a superior vena cava (SVC) approach to the great cardiac vein (GCV), and a left atrial (LA) catheter 60 introduced in the femoral vein and advanced along an inferior vena cava (IVC) approach across the interatrial septum into the left atrium. Each catheter includes a magnetic head (magnetic head 52 of catheter 50 and magnetic head 62 of catheter 60) along its distal portion such that, when magnetically coupled, the catheters provide a stable region to facilitate penetration of the tissue wall between the LA and GCV and subsequent advancement of a puncture guidewire 54 through the GCV catheter 50 and into the LA catheter 60. In particular, the trailing end of the puncture guidewire 54 is attached to one end (e.g., a suture) of the bridge element 12, and the other end is attached to a rear anchor 18 disposed in the distal portion of the GCV catheter 50. Such a configuration allows the bridge element 12 to be advanced across the left atrium by advancing the puncture guidewire 54 through the LA catheter 60 and out of the femoral vein while the magnetic heads remain magnetically coupled to one another, as shown in FIG. 13 . As can be seen by reference to FIG. 13 , the puncture guidewire 54 has a length that is longer than the combined length of the catheters so that the stiffness of the guidewire 54 allows the guidewire 54 to be manually advanced out of one vascular access point until it exits the other vascular access point. The guidewire 54 can be further retracted after exiting to pull the attached bridge element through the vascular pathway until it also exits the same vascular access point. Performing this process while the GCV catheter 50 and LA catheter 60 are magnetically coupled provides improved stability during the process and, more importantly, covers the puncture guidewire 54 and bridge element 12 while being pulled across the delicate tissue of the heart.Advantages of such a configuration include improved patient safety, single-operator deployment, significantly shortened deployment procedures, and reduced delivery device length and cost of goods compared to conventional delivery techniques. The advantages of such an approach in deploying an implant can be further understood by reference to the following figures, which describe the implant and associated components in more detail, as well as conventional approaches to delivering and deploying such implants.

[0031] Cardiac implants for the treatment / repair of heart valve annuli Implant structure 3A-3B show an embodiment of an implant 10 sized and configured to span the mitral valve annulus and extend across the left atrium in a generally anterior-posterior direction. The implant 10 includes a spanning region or bridge element 12 having a posterior anchor region 14 and an anterior anchor region 16.

[0032] The posterior anchor region 14 is sized and configured to allow placement of the bridging element 12 in a region of atrial tissue above the posterior mitral annulus. This region is preferred because it generally presents more tissue mass for lifting the posterior anchor region 14 than tissue regions at or adjacent to the posterior mitral annulus. Tissue engagement at this supraannular location may also reduce the risk of injury to the annular coronary artery. In a minority of cases, the circumflex coronary artery may pass above and medially on the left atrial aspect of the great cardiac vein, between the great cardiac vein in the left atrium and the endocardium. However, because the forces in the posterior anchor region are directed upward and medially relative to the left atrium, rather than in a constrictive manner along the long axis of the great cardiac vein, the likelihood of circumflex artery compression is reduced compared to other techniques in the field that constrict great cardiac vein tissue. Nevertheless, if coronary angiography reveals circumflex artery stenosis, the symmetric posterior anchor may be replaced with an asymmetric anchor, such as one T-shaped member with one limb shorter than the other, thereby avoiding compression of the circumflex artery at the crossing point. An asymmetric configuration may also be initially selected based on pre-placement angiography.

[0033] Asymmetric posterior anchors may also be utilized for other reasons. An asymmetric posterior anchor may be selected when a patient is deemed to have a severely stenotic distal great cardiac vein and an asymmetric anchor would work better to avoid occlusion of that vessel. Additionally, an asymmetric anchor may be selected for use in selecting to specifically and preferentially apply force to different points along the posterior mitral annulus to optimize treatment, for example, in cases of malformed or asymmetric mitral valves.

[0034] The anterior anchor region 16 is sized and configured to allow the bridging element 12 to be positioned against adjacent tissue in or near the right atrium once it passes through the septum and enters the right atrium. For example, as shown in FIGS. 3A-3B , the anterior anchor region 16 may be adjacent to or abut a region of fibrous tissue in the atrial septum. As shown, the anchor site 16 is desirably superior to the anterior mitral annulus at a height approximately equal to or greater than the height of the posterior anchor region 14. In the illustrated embodiment, the anterior anchor region 16 is adjacent to or near the inferior rim of the fossa ovalis. Alternatively, the anterior anchor region 16 may be positioned at a superior location within the septum, for example, at or near the superior rim of the fossa ovalis. The anterior anchor region 16 may also be positioned at a more superior or inferior location within the septum, away from the fossa ovalis, provided that the anchor site does not harm tissue within the region.

[0035] Alternatively, once the anterior anchor region 16 passes through the septum and enters the right atrium, it may be positioned within or otherwise extend to one or more additional anchors located within the surrounding tissue, such as within the superior vena cava (SVC) or inferior vena cava (IVC), or along the surrounding region.

[0036] During use, the spanning region or bridging element 12 can be positioned such that it is in tension between the two anchor regions 14 and 16. This allows the implant 10 to apply a generally direct mechanical force from posterior to anterior across the left atrium. The direct mechanical force can serve to shorten the short axis of the annulus (along line PA in FIG. 2E ). In doing so, the implant 10 can also reactively reshape the annulus along its long axis (line CM-CL in FIG. 2E ) and / or reactively reshape other surrounding anatomical structures. However, it should be understood that the presence of the implant 10 can serve to stabilize tissue adjacent to the heart valve annulus without affecting the length of the short or long axis.

[0037] It should also be understood that when located within other valve structures, the affected axes may not be the "long axis" and "short axis" due to surrounding anatomical structures. Additionally, for therapeutic use, implant 10 may only need to reshape the annulus during a portion of the cardiac cycle, such as during late diastole and early systole, when the heart is most filled with blood at the onset of ventricular contraction, when the majority of mitral valve leakage occurs. For example, implant 10 may be sized to limit outward displacement of the annulus during late ventricular diastolic relaxation as the annulus expands.

[0038] The mechanical force exerted by the implant 10 across the left atrium can restore a more normal anatomical shape and tension to the heart valve annulus and leaflets, which promotes leaflet coaptation during late ventricular diastole and early ventricular systole, thereby reducing mitral regurgitation.

[0039] In its most basic form, the implant 10 is made from a biocompatible metallic or polymeric material, or a metallic or polymeric material that has been appropriately coated, impregnated, or otherwise treated with materials to render it biocompatible, or a combination of such materials. The material is also desirably radiopaque or incorporates radiopaque features to facilitate fluoroscopic visualization.

[0040] In some embodiments, implant 10, or at least a portion thereof, may be formed by bending, forming, joining, machining, molding, or extruding a metal or polymer wire configuration, which may have flexible or rigid, inelastic or elastic mechanical properties, or a combination thereof. In other embodiments, implant 10, or at least a portion thereof, may be formed from a metal or polymer threaded or suture material. Materials from which implant 10 can be formed include, but are not limited to, stainless steel, nitinol, titanium, silicone, plated metals, Elgiloy™, NP55, and NP57.

[0041] In any of the implants described herein, the bridge member may be formed of a substantially inelastic material, such as a thread or suture material.

[0042] Posterior anchor area Posterior anchor region 14 is sized and configured to be placed in a supranullar position in or on the left atrium, for example, positioned in or near the left atrial wall above the posterior mitral annulus.

[0043] In the illustrated embodiment, the posterior anchoring region 14 is shown generally positioned at the level of the great cardiac vein, which runs adjacent to and parallel to most of the posterior mitral annulus. This extension of the coronary sinus can provide a strong and reliable fluoroscopic landmark when placing radiopaque devices or injecting contrast into the coronary sinus. As explained above, anchoring the bridging element 12 in this supra-annular position also reduces the risk of encroachment and injury to the circumflex coronary artery compared to procedures applied directly to the mitral annulus. Furthermore, the supra-annular position ensures no contact with the valve leaflets, thereby allowing coaptation and reducing the risk of mechanical injury.

[0044] The great cardiac vein also provides a site where the relatively thin, non-fibrous atrial tissue can be readily augmented and reinforced. To enhance retention or lift of posterior anchor region 14, which is essentially non-fibrous cardiac tissue, and to improve distribution of the forces exerted by implant 10, posterior anchor region 14 may include posterior anchors 18 disposed within the great cardiac vein and abutting venous tissue. This allows posterior anchor region 14 to be secured in a non-fibrous portion of the heart in a manner that can nevertheless maintain substantial retention or lift on that tissue for a substantial period of time without dehiscence, expressed in a clinically relevant time frame.

[0045] Anterior anchor area The anterior anchor region is sized and configured to allow the bridging element 12 to remain securely in place adjacent to or near the fibrous tissue and surrounding tissue on the right atrial side of the atrial septum. The fibrous tissue in this region provides superior mechanical strength and integrity compared to muscle, allowing the device to better resist pull-out. The septum is the most fibrous tissue structure within the heart itself.

[0046] When treated surgically, the septum is usually one of the only cardiac tissues where sutures can actually be placed, and muscle tissue can be expected to hold without pledgets or deep gripping when required.

[0047] As shown in Figures 3A-3B, the anterior anchor region 16 passes through the septal wall at a supra-annular location above the plane of the anterior mitral annulus. The anterior supra-annular distance can generally be equal to or greater than the posterior supra-annular distance. While the anterior anchor region 16 is shown at or near the inferior border of the fossa ovalis, other more inferior or superior locations within or outside the fossa ovalis can be used, taking into account the need to prevent harm to septal tissue and surrounding structures.

[0048] By positioning the bridging element 12 at this supranullar level within the right atrium, completely outside the left atrium and spaced well above the anterior mitral annulus, the implant 10 avoids the impossibility of endovascular coupling at or adjacent to the anterior mitral annulus, which has a very thin rim of annular tissue bounded anteriorly by the anterior leaflet, inferiorly by the aortic outflow tract, and medially by the atrioventricular node of the conduction system. At the anterior mitral annulus, the non-coronary leaflets of the aortic valve are attached to the mitral annulus via the central fibrous body. The anterior location of the implant 10 within the right atrium (either intraseptally or intravenously) at a supranullar level avoids the risk of encroachment and damage to both the aortic valve and the atrioventricular node.

[0049] The elevation of the anterior anchor region 16 in fibrous septal tissue is desirably augmented by a septal member 30, an anterior anchor 20, or a combination of both. Figures 3A and 3B show an anterior anchor region including a septal member 30. The septal member 30 can be an expandable device or a commercially available device such as a septal occluder, e.g., the Amplatzer® PFO Occluder (see Figures 5A-5B). The septal member 30 preferably mechanically enhances the retention or elevation of the anterior anchor region 16 in the fibrous tissue site. The septal member 30 also desirably at least partially increases the septum's reliance on adjacent anatomical structures to secure the position of the implant 10. In addition, the septal member 30 can also help to block or occlude small openings formed in the fossa ovalis or surrounding area during the implantation procedure.

[0050] Anticipating pinpoint tension applied to the septum by the anterior anchor region 16, the force acting on the septal member 30 should be spread over a moderate area without causing impingement on valvular, vascular, or conductive tissue. When tension or pulling force is transmitted to the annulus, short-axis shortening is achieved. A flexurally stiff septal member is preferred because it tends to avoid narrowing of the focus in the direction of tension on the left atrial bridge element as tension on the left atrial bridge element increases. The septal member 30 should also have a low-profile configuration and a highly cleanable surface to reduce thrombosis of the device deployed within the heart. The septal member may also have a collapsed configuration and a deployed configuration. The septal member 30 may include a hub 31 (see Figures 5A and 5B) to enable attachment of the anchor 20. A septal brace may also be used in combination with the septal member 30 and anterior anchor 20 to distribute forces evenly along the septum. Alternatively, a device within the IVC or SVC can be used as an anchoring site instead of being confined to the septum.

[0051] The location of the posterior and anterior anchor regions 14 and 16, respectively, with radiopaque bridge locks and well-defined fluoroscopic landmarks at the just-described supranullar tissue sites not only eliminates damage or localized impingement of vital structures, such as the circumflex artery, the atrioventricular node, and the left coronary and non-coronary processes of the aortic valve, but also eliminates the need for lift between the tissue and a directly tension-loaded, piercing / engaging / retaining tissue attachment mechanism. Instead, physical structures and force-distributing mechanisms, such as stents, T-shaped members, and septal members, can be used that better accommodate the attachment or abutment of mechanical levers and bridge locks and better distribute potential tissue-tearing forces. Furthermore, the anchor sites 14 and 16 do not require the operator to use complex imaging. Adjustment of the implant position after or during implantation is also facilitated without these constraints. The anchor sites 14, 16 also allow for complete intra-atrial retrieval of the implant 10 by endovascular snaring on either side of the left atrial wall where the implant 10 emerges, followed by severing the bridging element 12.

[0052] Bridge Element Orientation In the embodiment shown in Figures 3A-3B, implant 10 is shown spanning the left atrium, beginning at a posterior focal point above the approximate midpoint of the mitral annulus and proceeding anteriorly in a generally linear path directly to the region of the anterior focal point of the septum. The spanning region or bridge element 12 of implant 10 may be preformed or otherwise configured to extend in this essentially linear path in the plane of the valve without significant deviation in height toward or away from the annular plane, except as determined by the height difference between the posterior and anterior regions of placement. It will be understood that such implants may include bridge members with lateral or medial deviation and / or superior or inferior deviation, and may include bridge members that are rigid or semi-rigid and / or substantially fixed in length.

[0053] Rear and front anchors It should be understood that devices are described in which the anchors described herein, including posterior or anterior anchors, can releasably hold bridging element 12 in tension. As seen in Figures 4A-4B, anchors 20 and 18, respectively, are shown releasably secured to bridging element 12, allowing the anchor structure to move back and forth independently of the atrial septum and medial wall of the great cardiac vein during a portion of the cardiac cycle when tension can be reduced or zeroed.

[0054] Alternative embodiments are also described, all of which may provide this functionality. It should also be understood that the general description of posterior and anterior anchors is not limited to anchor functionality, e.g., posterior anchors may be used anteriorly and anterior anchors may be used posteriorly.

[0055] When the bridge element is in abutting relationship with the septal member (e.g., an anterior anchor) or T-shaped member (e.g., a posterior anchor), the anchor allows the bridge element to move freely within or around the septal member or T-shaped member; for example, the bridge element is not connected to the septal member or T-shaped member. In this configuration, the bridge element is held in tension by the locking bridge stop, whereby the septal member or T-shaped member serves to distribute the force exerted by the bridge element over a larger surface area. Alternatively, the anchor can be mechanically connected to the septal member or T-shaped member, for example, when the bridge stop is positioned on and secured to the septal member hub. In this configuration, the bridge element is fixed relative to the position of the septal member and does not move freely around the septal member.

[0056] 6A-6B show perspective views of exemplary locking bridge stops 20 according to the present invention. Each bridge stop 20 preferably includes a fixed upper body 302 and a movable lower body 304. Alternatively, the upper body 302 may be movable and the lower body 304 may be fixed. The upper and lower bodies 302, 304 are positioned around a tubular shaped rivet 306. The upper and lower bodies 302, 304 are preferably held in place by a rivet head 308 and a base plate 310. The rivet 306 and base plate 310 include a predetermined inner diameter 312 sized to allow the bridge stop 300 to be placed over a guidewire. A spring, such as a spring washer 314, also known in the mechanical arts as a Belleville spring, is positioned around the rivet 306, between the rivet head 308 and the upper body 302, and applies an upward force to the lower body 304. The lower body 304 is movable between a bridge unlocked position (see FIG. 6A ) and a bridge locked position (see FIG. 6B ). In the bridge unlocked position, the lower body 304 and the upper body 302 are not in contact, creating a groove 320 between the upper body 302 and the lower body 304. In the bridge locked position, the axial force of the spring washer 314 urges the lower body 304 into contact with or near contact communication with the upper body 302, thereby locking the bridge element 12, which is positioned within the groove 320, into position by applying the axial force of the lower body 304 to the upper body 302. During use, the bridge element 12 is positioned within the groove 320 while the lower body 304 is maintained in the bridge unlocked position 316. The bridge stop 300 is positioned relative to the septum member 30, and the bridge element 12 is adjusted to the appropriate tension. The lower body 304 is then moved toward the upper body 302, thereby fixing the position of the bridge stop 300 on the bridge element 12. While this example shows a particular locking bridge stop design, it will be understood that any suitable lock can be used, including any of the types described in U.S. Patent Application Publication No. 2017 / 0055969.

[0057] 7A-7B show alternative cardiac implants suitable for delivery using the methods and delivery systems described herein. FIG. 7A shows an implant 10' having a T-shaped posterior anchor 18 and a T-shaped anterior anchor 70 in the great cardiac vein. The anterior T-shaped bridge stop 75 can be any of the configurations of the T-shaped bridge stop embodiments described. The T-shaped member 75 includes a lumen 75 extending therethrough perpendicular to the length of the T-shaped member. The bridge element 12 can be secured by a free-floating bridge stop as previously described. FIG. 7B shows an implant 10″ having a T-shaped posterior anchor 18 and a lattice-style anterior anchor 76 in the great cardiac vein. The lattice 77 is positioned on the septal wall at or near the fossa ovalis. Optionally, the lattice 77 may include reinforcing struts 78 to distribute the tension of the bridging elements 12 over a larger area on the septal wall. The anterior lattice-style bridge stop 76 may be implemented in a deployment catheter through the center of which the bridging elements 12 pass. The lattice 77 is preferably self-expanding and may be deployed by a plunger. The bridging elements 12 may be secured by a free-floating bridge stop as previously described. It will be understood that various other such implants utilizing the same concepts as the implants described above may be devised for delivery and deployment using the systems and methods described herein.

[0058] 8A-8B show alternative methods of connecting a bridge element 12 to a T-shaped posterior anchor. FIG. 8A shows a T-shaped member 18 in which the bridge element 12 is wrapped around a central portion of the T-shaped member. The bridge element 12 can be secured, for example, by adhesive 712, a knot, or a securing band disposed on the bridge element 12. Alternatively, the bridge element 12 can first be threaded perpendicularly down the length of the T-shaped member through a lumen 714 extending through the T-shaped posterior anchor 18. The bridge element 12 can then be wrapped around the T-shaped member and secured, for example, by adhesive 712, a securing band, or a knot. FIG. 8B shows a T-shaped member 18 in which the bridge element 12 is welded or forged to a plate 716. The plate 716 can then be embedded within the T-shaped member 710 or alternatively secured to the T-shaped member 710 by, for example, gluing or welding. It will be appreciated that a variety of other bonds can be used to secure the bridge element 12 and posterior anchor 18 and facilitate delivery with the systems and methods described herein.

[0059] 9A-9B show an alternative anchor suitable for use as a posterior anchor in a cardiac implant according to the present invention. FIG. 9A is a perspective view of a T-shaped anchor 18′ including an intravascular stent 80 and, optionally, reinforcing struts 81. Stent 80 may be a balloon-expandable or self-expanding stent. As described above, T-shaped anchor 18′ is preferably connected to a predetermined length of bridge element 12. Bridge element 12 may be retained in, on, or around T-shaped bridge stop 80 by using any of the bridge locks described above, or may be connected to T-shaped anchor 18 by, for example, bonding, welding, or gluing, or any combination. FIG. 9B shows a T-shaped anchor 18″ that includes a flexible tube 90 having a predetermined length, e.g., 3-8 centimeters, and an inner diameter 91 sized to allow at least a guidewire to pass therethrough. The tube 90 is preferably braided, but may be solid as well and coated with a polymeric material. Each end of the tube 90 preferably includes a radiopaque marker 92 to aid in placement and positioning of the T-shaped anchor. The tube 90 also preferably includes an atraumatic end to protect the vessel wall. The tube generally conforms to the curved shape of the great cardiac vein or atrial septum and prevents trauma to the surrounding tissue. The posterior anchor 18 may be curved or pre-shaped to provide less resistance to bending. A reinforcing central tube 93 may also be included to add rigidity to the anchor and help prevent back-out of the anchor from the great cardiac vein and left atrial wall. The bridging element 12 extends through a central hole 94 inside the reinforcing central tube 93. Each of the described anchors can be straight, curved, or flexible in shape to accommodate the anatomy. It will be understood that various other types of anchors can use the posterior anchor 18 attached to the bridging element 12 for delivery and deployment using the systems and methods described herein.

[0060] General Methods of Delivery and Implantation The implant system 10 described herein can be implanted within the heart valve annulus in a variety of ways. Preferably, the implant 10 is implanted using a catheter-based technique via a peripheral venous access site, such as the femoral or jugular vein (via the IVC or SVC) under image guidance, or via an intra-arterial retrograde approach from the femoral artery through the aorta to the left atrium, also under image guidance. As explained above, the implant 10 comprises separate components that are assembled in vivo to form the implant and are delivered to and assembled in the body from outside the body through the interaction of multiple catheters.

[0061] Traditional Delivery Methods 10A-12D illustrate the deployment of an implant 10 of the type shown in FIGS. 3A-3B into the femoral or jugular vein, or typically both, by a percutaneous catheter-based procedure under image guidance using conventional methods, such as any of those described in U.S. Patent Application Publication No. 2017 / 0055969.

[0062] Percutaneous vascular access to the femoral or jugular veins, or typically a combination of both, is achieved by conventional methods. As shown in FIG. 10A, under image guidance, a first catheter, or GCV catheter 40, is advanced along a GCV guidewire 54 from the superior vena cava (SVC) route accessed from a vein in the neck (e.g., the jugular vein) into the great cardiac vein. As shown in FIG. 10B, an LA catheter 60 is advanced from the right atrium via the inferior vena cava (IVC) accessed from the femoral vein, typically through the septum at or near the fossa ovalis, into the left atrium. The septal wall of the fossa ovalis is punctured with a transseptal needle, and an LA guidewire 74 is advanced through the septum into the left atrium. Typically, a large-bore (12-16 French) "Mullins"-shaped hemostatic sheath is placed in the LA to serve as a conduit for the atraumatic placement or removal of subsequent devices from the LA along the route to or within the LA. The LA catheter 60 is then advanced through the sheath into the left atrium.

[0063] Each of the catheters 40, 60 includes a magnetic head 42, 62, respectively, disposed along its distal portion, configured to facilitate magnetic coupling when positioned at a desired orientation and location across the tissue wall between the left atrium and the great cardiac vein. As shown in FIGS. 11A-11B, the LA catheter 60 includes a distal magnetic head with a north-south magnetic pole disposed axially along the catheter, while the GCV catheter 40 includes a distal magnetic head with a north-south magnetic pole disposed laterally relative to the catheter's longitudinal axis. This arrangement facilitates lateral or perpendicular magnetic coupling between the respective catheters, as shown in FIGS. 11B-11C, and allows for the passage of a penetrating element or guidewire, typically from a channel in one magnetic head to a corresponding channel in the other magnetic head. In this approach, the penetrating element is a puncture guidewire 54 with a sharpened distal end. Typically, the puncture guidewire 54 is advanced through a curved channel 43 in the magnetic head 42 of the GCV catheter 40 and into a funnel-shaped channel 67 in the magnetic head 62 of the LA catheter 60. In this embodiment, the magnetic head of the GCV catheter 40 has a single magnet, although it will be understood that various other embodiments can include a magnetic head with additional magnets oriented to facilitate the desired alignment, for example, a three-magnet head in which the central magnet has magnetic poles oriented laterally relative to the axis of the catheter between two magnets whose magnetic poles are axially oriented, as shown in U.S. Patent Application Publication No. 2017 / 0055969.

[0064] Next, as shown in FIG. 12A , the penetrating guidewire is advanced through the LA catheter 60 until it exits the femoral artery access point at the groin. The left atrial magnetic catheter A is then replaced by a very long exchange catheter 28, which is carefully pushed across the puncture site along the great cardiac vein to interface with the great cardiac vein magnetic catheter 40. The exchange catheter 28 is pushed simultaneously with the removal of the great cardiac vein magnetic catheter 40 to avoid exposing the puncture wire to tissue. Exposure of the puncture wire during this process can easily slice tissue if the wire moves or is tensioned during removal or replacement of one of the catheters. This process typically requires two operators, one pushing the exchange catheter while the other simultaneously removes the great cardiac vein magnetic catheter, often using visualization techniques to ensure the two catheters are interfaced and the puncture wire remains covered. Once the exchange catheter 28 is positioned in the neck and groin area, the puncture wire is removed and replaced with a left atrial extension guidewire 74, as shown in Figure 12B.

[0065] Next, the extension guidewire 74 is gently retracted, causing the bridge element 12 to follow through the vasculature. If an optional exchange catheter 28 is used (as shown in FIGS. 12A-12B ), the extension guidewire 74 is retracted through the lumen of the exchange catheter 28 without traumatizing the tissue. The extension guidewire 74 is then completely removed from the body at the femoral vein, leaving the bridge element 12 to extend from outside the body (preferably at the femoral sheath), through the vasculature, and exit again at the superior vena cava sheath. The extension guidewire 74 can then be removed from the bridge element 12 by cutting or detaching the bridge element 12 at or near the interface bond 800 between the bridge element 12 and the extension guidewire 74. The leading end of the extension guidewire 74 is attached to one end of the bridge element (e.g., suture material), and the other end of the bridge element is attached to a posterior anchor and held within the posterior anchor delivery catheter 115. As seen in Figure 12B, the extension guidewire 74 is gently retracted, allowing the bridging element 12 to follow into the exchange catheter 28 and through the vasculature.

[0066] A posterior anchor 120 disposed within the deployment catheter 24 is connected to the posterior end of the bridge element 12 extending from the superior vena cava. While a T-shaped anchor is shown here, it will be understood that various other types of posterior anchors (e.g., stents, half-stents, etc.) can be used. The deployment catheter 24 is then positioned onto or over the GCV guidewire 54 and abuts the exchange catheter 28. A push-and-pull process by two operators repeatedly pushes the posterior anchor delivery catheter 115 while simultaneously removing the exchange catheter 28 to position the posterior anchor within the great cardiac vein, with the bridge element extending across the left atrium.

[0067] Optionally, to facilitate advancement of the posterior anchor 120 and bridge element into position within the great cardiac vein and across the left atrium, the bridge element 12 may be pulled from the femoral vein area, either individually or in combination with the deployment catheter 24. The GCV guidewire 54 is then retracted to separate the T-anchor 120 from the GCV guidewire 54 and deployment catheter 24. Once separation is confirmed, preferably under image guidance, the bridge element 12 is gently pulled to position the T-anchor 120 against venous tissue within the great cardiac vein and center it within the GCV access lumen 115. The deployment catheter 24 and exchange catheter 28 may then be removed. The T-anchor 120 with attached bridge element 12 remains within the great cardiac vein. The length of the bridge element 12 extends from the posterior T-anchor 120, through the left atrium, through the fossa ovalis, and through the vasculature, preferably remaining accessible from outside the body. The bridge element 12 is now ready for the next step of establishing the anterior anchor region 16 as described above and shown in Figures 16C-16D.

[0068] Once the posterior anchor region 14, bridge element 12, and anterior anchor region 16 are configured as described above, tension is applied to the bridge element 12. The implant 10 and associated regions are allowed to rest for a predetermined period of time, e.g., 5 seconds or more. The mitral valve and mitral regurgitation are observed for the desired therapeutic effect. The tension on the bridge element 12 can be adjusted until the desired result is achieved. The anchors 20 are then secured to the bridge element 12 using the locking bridge stop 30 when the desired tension or measured length or degree of reduction in mitral regurgitation is achieved.

[0069] Improved delivery methods and related catheter systems In one aspect, improvements to anchor delivery catheters allow for the delivery and deployment of the implants described above with fewer catheters, improving ease of use compared to the conventional approaches described above. In some embodiments, the catheter system includes an anchor delivery catheter having a distal magnetic portion that facilitates access to the heart chamber from within the adjacent vasculature, which facilitates access to the heart chamber by passing a penetrating guidewire to a magnetically coupled catheter within the heart chamber. In some embodiments, the anchor delivery catheter is configured for delivery of a bridging element across the heart chamber (e.g., the left atrium) once access is achieved, and subsequent deployment of the anchor within the vasculature (e.g., the great cardiac vein). In some embodiments, the bridging element is attached to the trailing end of the penetrating guidewire, while the other end is attached to a rear anchor disposed in the distal portion of the delivery catheter. This allows the bridging element to be advanced through a penetration between the heart chamber and the vasculature by continuously advancing the penetrating guidewire from one vascular access point (e.g., the jugular vein) and exiting the body at a second vascular access point (e.g., the femoral vein).

[0070] In some embodiments, the anchor delivery device is a GCV catheter 50 for delivery of a posterior anchor 18 within the GCV, as shown in FIG. 13 . The catheter 50 preferably includes a magnetic or ferromagnetic head 52 positioned along the distal portion of the catheter shaft. Optionally, a hub can be positioned at the proximal end. The catheter shaft can include a proximal section that is generally rigid to allow for torque functionality of the shaft, which can be a solid or braided structure. The proximal section includes a predetermined length (e.g., 50 centimeters or more) to allow for positioning of the shaft within the vasculature structure. The distal section, which defines the distal portion, can be generally flexible to allow for maneuverability within the vasculature, for example, within a cavity or vasculature of the heart. The distal section can also be a predetermined length (e.g., 10 centimeters or more) suitable for manipulation within the heart. The inner diameter or lumen of the catheter shaft is preferably sized to allow for the passage of a GCV guidewire 15, a penetrating guidewire, and a bridging element. The GCV catheter 50 preferably includes radiopaque markers to facilitate adjustment of the catheter under image guidance to align it with the LA catheter 60. The magnetic or ferromagnetic head 52 is preferably polarized to magnetically attract or couple with the distal end of the LA catheter 60, as previously described. The magnetic head 52 includes a guide channel formed therein to facilitate passage of a penetrating guidewire through the channel and into a corresponding channel in the magnetic head of the LA catheter 60.

[0071] Similar to the GCV catheter 50, the LA catheter 60 preferably includes a magnetic or ferromagnetic head 62 positioned at its distal end. The catheter shaft may include proximal and distal sections similar to those of the catheter 50 described above. The proximal section may be generally rigid to allow for shaft torqueability and may be of axial or braided construction. The distal section includes a predetermined length, e.g., 90 centimeters, to allow for shaft positioning within the vasculature. The distal section may be generally flexible and anatomically shaped to allow for maneuverability through the fossa ovalis and into the left atrium. The distal section may also include a predetermined length, e.g., 10 centimeters. The inner diameter or lumen of the catheter shaft is preferably sized to allow for passage of the LA guidewire 74 and, in addition, to accommodate the penetrating guidewire 54 passed from the GCV and subsequently the bridge element 12 attached thereto. The LA catheter 60 may also include radiopaque markers to facilitate image-guided adjustment of the catheter 60 to align it with the GCV catheter 50. The magnetic or ferromagnetic head 62 of the LA catheter 60 is magnetic so as to magnetically attract or couple to the distal end of the GCV catheter, for example, as shown in Figures 11A-11C. It will be appreciated that the magnetic force in the head 62 can be reversed so long as the magnetic poles of attraction in the LA catheter 60 and the GCV catheter 50 are aligned.

[0072] While particular magnetic head configurations are described above, it will be understood that various other magnetic head configurations may be used, for example, any of those described in U.S. Patent Application Publication No. 2017 / 0055969. Detailed examples of such catheter configurations are further described in Figures 17-19.

[0073] A system of the present invention including a catheter with an alternative magnet head configuration is shown in Figure 27. This design reduces the amount of steps the practitioner must perform to align the magnets of the LA magnet catheter and GCV catheter, and improves visualization of the alignment of the penetrating guidewire and catheter as they traverse the left atrial wall.

[0074] Referring to FIG. 27 , the system includes first and second magnetic catheters. FIG. 27 shows the distal regions of the first and second magnetic catheters, illustrating the magnet placement within their respective magnetic heads. A first catheter 1300 for advancement to the GVC has a proximal end and a distal end (distal end shown in FIG. 27 ) and includes a first lumen extending through the length of the first catheter, a first magnet 1320 disposed along a distal portion of the first catheter, and a first guide channel 1330 disposed in the distal portion of the first catheter and extending along a first longitudinal axis. In various embodiments, the first magnet 1320 includes a first magnetic pole 1340 and a second magnetic pole 1350. Additionally, the first guide channel 1330 is coextensive with the first lumen and has a first side hole 1360 disposed proximally along the distal portion of the first catheter relative to the first magnetic pole 1340.

[0075] A second catheter 1310 for advancement into the LA has a proximal end and a distal end (distal end shown in FIG. 27 ) and includes a second lumen extending through the length of the second catheter, a second magnet 1370 disposed at the distal end of the second catheter, and a second guide channel 1380 disposed at the distal end of the second catheter and extending along a second longitudinal axis. In various embodiments, the second magnet 1370 includes a third magnetic pole 1390 and a fourth magnetic pole 1400. Additionally, the second guide channel is coextensive with the second lumen and has a second side hole 1410 adjacent to the second magnet 1370.

[0076] The first magnet 1320 and the second magnet 1370 are configured to automatically align the distal portions of the first catheter 1300 and the second catheter 1310 and magnetically couple with the distal portions of the first catheter 1300 and the second catheter 1310 such that they are substantially perpendicular to each other (approximately 90 degrees relative to each other) when coupled (as shown in FIG. 27 ). Thus, the first magnetic pole 1340 and the third magnetic pole 1390 have opposite polarities and are close to each other when magnetically coupled. For example, the first magnetic pole 1340 is positive polarity and the third magnetic pole 1390 is negative polarity. In this configuration, the first magnetic pole 1340 and the second magnetic pole 1350 are disposed perpendicular to the longitudinal axis of the first guide channel 1330, and the third magnetic pole 1390 and the fourth magnetic pole 1400 are disposed parallel to the longitudinal axis of the second guide channel 1380, with the third magnetic pole 1390 distal to the fourth magnetic pole 1400 along the distal end of the second catheter 1310. It will be understood that the magnetic forces of the first magnet 1320 and the second magnet 1370 can be reversed, so long as the magnetic poles within the first catheter 1300 and the second catheter 1310 are aligned.

[0077] Upon magnetic coupling of first magnet 1320 and second magnet 1370, first side hole 1360 and second side hole 1410 are aligned in a plane parallel to the longitudinal axis of first guide channel 1330 and the second longitudinal axis of second guide channel 1380 such that an advancing traverse wire may traverse through first guide channel 1330, exit first side hole 1360, enter second side hole 1410, and traverse second guide channel 1380. Additionally, upon magnetic coupling, second side hole 1410 is oriented distally along the distal portion of the first catheter relative to first side hole 1360, as shown in FIG. 29 . In this configuration, first side hole 1360 and second side hole 1410 are substantially perpendicular to one another.

[0078] 27 and 29 , to facilitate passage of the transverse wires from the first guide channel 1330 through the second guide channel 1380, the second magnet 1370 includes a curved recess having an arcuate or angled surface 1420 oriented toward and defining the surface of the second guide channel 1380. In various embodiments, the arcuate or angled surface 1420 extends from a distal portion of the second magnet 1370 to a proximal portion of the second magnet.

[0079] It will be appreciated that this configuration works by allowing the magnet catheter to be attached at a 90 degree angle. This magnet shape aids in the translation of the penetrating guidewire into the LA catheter shaft attached to 1380. As shown in FIG. 27, the magnet polarity is defined so that the LA catheter magnet and the GCV catheter magnet 1320 are always attached.

[0080] In some embodiments, one or more magnets of the catheter are coated with a smooth gold plating to reduce friction during traversal, hi some embodiments, the second magnet 1370 is coated with a friction-reducing material such as gold to reduce friction during traversal.

[0081] Additionally, in some embodiments, the steerer tube is designed and positioned so that the penetrating guidewire approaches the LA catheter's magnet 1370 at an angle that reduces the amount of friction within the system. Furthermore, as will be discussed, the magnet 1370 has an internal shape that helps guide the penetrating guidewire down the LA catheter shaft.

[0082] To facilitate visualization of the catheters during advancement and magnetic coupling, the first catheter 1300 and / or the second catheter 1310 may include one or more radiopaque markers disposed at their respective distal ends. As shown in FIG. 27 , the first catheter 1300 includes a radiopaque marker 1430 disposed at its distal end. The second catheter 1310 may also include a radiopaque marker disposed at its distal end. In some embodiments, the distal portion of the second catheter 1310 includes a magnet housing 1440 constructed of a material that is translucent under fluoroscopy, thereby allowing the crossing wire to be viewed and / or tracked during the crossing procedure. As shown in FIG. 22A , the first and second catheters may also include additional radiopaque markers.

[0083] Additionally, in some embodiments, the first and / or second catheters may include one or more radiopaque markers disposed along their respective lengths. For example, the first and / or second catheters may include a series of radiopaque markers disposed along their respective lengths at spaced intervals, allowing a user to determine the depth of insertion of each catheter within the vasculature or body. Figure 30 shows a first catheter 1300 having a series of radiopaque markers 1450 disposed along the length of the catheter.

[0084] Additionally, in some embodiments, the penetrating guidewire comprises a nitinol wire with a platinum / iridium (PTIR) core to enhance imaging of the wire and improve the practitioner's ability to maintain visibility of the wire during the procedure.

[0085] How to transplant Access to the vascular system is generally provided through the use of introducers known in the art. For example, a 16F or smaller hemostatic introducer sheath (not shown) may first be positioned in the superior vena cava (SVC) to provide access to the GCV catheter 50. Alternatively, an introducer may be positioned in the subclavian vein. Then, a second 14F or smaller introducer sheath (not shown and not described above) may be positioned in the right femoral vein to provide access to the LA catheter 60. For example, access to both the SVC and right femoral vein allows the implantation method to utilize a looped guidewire. For example, in the procedure described below, a looped guidewire is created by advancing the LA guidewire through the vascular system until it exits the body and extends outside both the superior vena cava sheath and the femoral sheath. The LA guidewire may follow an intravascular path extending at least from the superior vena cava sheath through the interatrial septum to the left atrium, from the left atrium through atrial tissue, and through the great cardiac vein to the femoral sheath.

[0086] 14A-16D illustrate an implantation method utilizing a magnetic anchor delivery catheter according to an embodiment of the present invention. FIGS. 14A-14B illustrate the positioning of a GCV anchor delivery catheter 50 within the great cardiac vein adjacent to the posterior annulus of the mitral valve. First, as shown in FIG. 14A, under image guidance, for example, a GCV guidewire 15 (e.g., a 0.035-inch guidewire) is advanced into the coronary sinus along the SVC approach to reach the great cardiac vein. Optionally, an injection of contrast with an angiography catheter can be performed from the aorta to the left aorta, and images of the left coronary artery system can be taken to assess the location of the vital coronary anatomy. Contrast injection can also be performed into the great cardiac vein to provide images and measurements. If the great cardiac vein is too small, it can be dilated with a 5-12 millimeter balloon, for example, halfway up the posterior valve leaflet.

[0087] As shown in FIG. 14B, the GCV catheter 50 is advanced over the GCV guidewire 15 so that the distal magnetic head 52 and posterior anchor 18 are positioned at or near the desired location in the great cardiac vein, for example, near the center of the posterior valve leaflet or posterior mitral annulus. The desired location of the GCV catheter 50 may also be considered approximately 2 to 6 centimeters from the anterior interventricular venous takeoff. Once the GCV catheter 50 is positioned, an injection may be performed to confirm sufficient blood flow around the GCV catheter 50. If blood flow is low or absent, the GCV catheter 50 may be withdrawn into the coronary sinus until needed.

[0088] As shown in FIG. 14C, the LA catheter 60 is then deployed into the left atrium. From the femoral vein, under image guidance, an LA guidewire 16, e.g., a 0.035-inch guidewire, is advanced into the right atrium. A 7 Fr Mullins dilator with a transseptal needle (not shown) can be deployed into the right atrium. An injection is made into the right atrium to position the fossa ovalis at the septal wall. The septal wall of the fossa ovalis can be punctured with the transseptal needle, and the guidewire 16 is advanced into the left atrium. The transseptal needle is then removed, and the dilator is advanced into the left atrium. An injection is made to confirm its position relative to the left ventricle. The Mullins system is then removed and replaced with a 12 Fr or other appropriately sized Mullins system. The 12 Fr Mullins system is positioned in the right atrium and extended a short distance into the left atrium, and the LA catheter 60 is advanced into the left atrium. After advancing the LA catheter 60 into the left atrium, the catheter's distal magnetic head 62 is positioned adjacent to the great cardiac vein so as to magnetically couple with the magnetic head 52 of the GCV magnetic catheter 50, for example, as shown in FIGS. 11A-11C , and the magnetic head automatically aligns the lumens of the LA catheter 60 and the GCV catheter 50. Similarly, after advancing the second magnetic catheter 1310 into the left atrium, the catheter's distal magnet 1370 is positioned adjacent to the great cardiac vein so as to magnetically couple with the magnet 1320 of the first magnetic catheter 1300, for example, as shown in FIG. 27 . The magnet automatically aligns the lumens of the second LA catheter 1310 and the first GCV catheter 1300. It will be understood that in various embodiments, any of the methodologies of the present invention may employ any suitable sized sheath system, such as a 12 Fr, 14 Fr, etc. In one embodiment, a 14 Fr sheath system is used.

[0089] 14D , once magnetically coupled, the puncture guidewire 54 is advanced through the GCV catheter 50, penetrating the tissue wall between the great cardiac vein and the left atrium and entering the lumen of the magnetic head 62 of the LA catheter 60. The operator continues to advance the guidewire through the lumen of the LA catheter 60 until the puncture guidewire 54 exits the body (e.g., at the groin). Because the trailing end of the puncture guidewire is attached to one end (e.g., a suture) of the bridge element 12 and the other end of the bridgewire is attached to the posterior anchor 18, once the puncture guidewire 54 exits the proximal end of the LA catheter 60, the puncture wire 54 is pulled proximally from the LA catheter 60, thereby pulling the bridge element 12 through the GVC catheter 50, across the left atrium within the LA catheter 60, through the vasculature, and out the body at the hip, all while the LA catheter 60 and GVC catheter 50 remain magnetically coupled. This approach ensures that the puncture wire 54 and bridge element 12 remain covered while being drawn through the vasculature over the delicate tissue of the heart. This avoids cutting or slicing the tissue with the bridge element as it is pulled across it, and further avoids the cumbersome push and pull procedure and use of exchange catheters described in prior approaches.

[0090] As shown in FIG. 15A , the bridge element 12 extends from a posterior anchor 18 disposed within the distal portion of the GCV catheter 50, spans the left atrium, extends through the LA catheter 60, and exits the body at the femoral vein. The operator can gently tug on the bridge element 12 to remove any slack from the system and ensure it is properly positioned. In some embodiments, this action can also facilitate release of the posterior anchor 18 from the GCV delivery catheter 50. As shown in FIG. 15B , the LA catheter 60 can be decoupled from the GCV catheter 50 and withdrawn while the bridge element remains in place. Optionally, the LA catheter 60 can remain in the left atrium extending through the septum until the posterior anchor 18 is fully deployed.

[0091] As shown in FIG. 15C , the GCV catheter 50 is optionally adjusted to position the posterior anchor 18 along the penetration for subsequent release from the catheter. The posterior anchor 18 can be released from the GCV delivery catheter 50 by proximally retracting the GCV guidewire 15 extending through the posterior anchor 18. Optionally, the catheter configuration can include a releasable coupling mechanism, such as a tether 903, that secures the posterior anchor 18 to the distal portion of the GCV catheter 50 and extends from the proximal end, allowing the operator to pull the tether proximally to release the posterior anchor 18. The tether can be defined as a wire or suture that frictionally engages the posterior anchor in place at one end and extends proximally from the catheter at the other end, or as a tether loop that wraps around the posterior anchor and interfaces with a mechanism along the distal portion of the GCV catheter, with both ends extending proximally from the catheter to allow the tether to be released. It will be appreciated that various types of releasable couplings may be used, including any of those described in U.S. Patent Application Publication Nos. 2007 / 0265658 and 2012 / 0016456, which are incorporated herein by reference in their entireties.

[0092] During this process, the GCV catheter 50 can be slightly retracted, particularly in embodiments where the posterior anchor 18 partially resides in the recessed portion of the magnetic head 52. In many cases of complete or partial removal of the GCV catheter, the guidewire is left in the GCV anchor and can be retrieved until the end of the procedure. In this embodiment, the posterior anchor 18 is an elongated member, such as a T-bar anchor, but it will be understood that various other deployment steps can be used to facilitate the deployment of other types of posterior anchors. For example, if the posterior anchor 18 is a scaffold or stent-like structure, any suitable means for deploying such a structure can be used. For example, a restraining sheath partially disposed over a self-expanding scaffold can be retracted, thereby releasing the scaffold from the magnetic head portion 52 or a balloon-expandable scaffold, or an otherwise releasable scaffold can be used. Once the posterior anchor 18 is deployed, the GCV catheter 50 and GCV guidewire can be removed, as shown in FIG. 15D.

[0093] As shown in FIG. 16A, the posterior anchor 18 deployed in the great cardiac vein is attached to a bridge element 12 spanning the left atrium, extending through the vasculature along the IVC pathway and exiting the femoral vein in the groin. Because the bridge element 12 has not yet been tensioned, there is little chance of cutting or damaging tissue at this point. Next, as shown in FIG. 16B, the anterior anchor delivery catheter 26 is advanced along the bridge element 12, and the anterior anchor deployed with the bridge element passes through its central hub. The delivery catheter 26, carrying the anterior anchor 30, is collapsed inside the delivery sheath and disposed at its distal end, with the bridge element passing through its central hub. As shown in FIG. 5B, the collapsed anterior anchor is guided along the septal wall and deployed to the FO or other suitable location.

[0094] As shown in FIG. 16C, the anterior anchor 30 is deployed through the delivery sheath and along the septal wall with the proximal locking bridge stop 20. The length of the bridge element 12 can then be gradually adjusted and held in place by the bridge lock 20 at each adjustment until observation of the heart pump indicates improvement in valve function. Excess bridge element 12 can then be cut with the catheter's cutting element or by using a separate cutting catheter advanced along the bridge element 12. Next, as shown in FIG. 16D, the LA delivery catheter 60 can be removed, leaving the fully deployed implant 10 in place within the heart.

[0095] In a similar embodiment, the present invention provides a method of performing a surgical procedure on a subject using the system of the present invention, as shown in FIG. 27 . The method includes inserting a first catheter 1300 through a first vascular access site and advancing the first catheter 1300 to a first location within or adjacent to the subject's heart. A second catheter 1310 is inserted through a second vascular access site and advanced to a second location within or adjacent to the heart, the first and second locations being separated by a cardiac tissue wall. The first catheter 1300 and the second catheter 1310 are positioned such that the first magnet 1320 and the second magnet 1370 are magnetically coupled across the tissue wall. Next, while the first and second catheters are magnetically coupled, the tissue wall is penetrated with a penetrating member, such as a penetrating guidewire, advanced through the first catheter 1300, across the tissue wall, and through the second catheter 1310. In some embodiments, the method further includes determining a depth of insertion of the first catheter and / or the second catheter via radiopaque markers disposed along the length of each of the catheters (shown in FIG. 30 ) prior to magnetically coupling the first magnet 1320 and the second magnet 1370. The method further includes, while the first magnet and the second magnet are magnetically coupled, advancing a posterior anchor and a bridge element coupled to the posterior anchor at a first end of the bridge element from the first vascular access site to a first location, advancing a second end of the bridge element through the penetrated tissue wall and into the second catheter, and advancing an anterior anchor along the bridge element from the second vascular access site to deploy the anterior anchor at a third location within the heart, wherein the bridge element spans a cavity of the heart, as shown in FIGS.

[0096] Figure 36 illustrates the use of the catheter system of the present invention to advance a posterior anchor into the GCV via the left atrium. As shown in Figures 36 and 37-45, in some embodiments, the posterior anchor is delivered into the GCV from the left atrium. While in the GCV, a GCV catheter, e.g., a first catheter, is hollowed with a hollow opening facing the left atrium (the recess toward the left atrium). The posterior anchor is guided down an LA catheter, e.g., a second catheter, across the tissue, and deposited in the trough of the GCV catheter. A crossing wire is required beforehand to facilitate tracking of the posterior anchor through the crossing hole in the LA wall.

[0097] Figures 37-45 illustrate portions of a procedure in which a penetrating member (e.g., a crossing wire) is advanced from the left atrium into the GCV and a posterior anchor is advanced from the left atrium into the GCV using the magnetic catheter system of the present invention. Figure 37 shows that the magnetic heads of the LA and GCV catheters are magnetically coupled, with the GCV wall sandwiched between the magnetic heads of the respective catheters. As shown in Figure 38, the penetrating member, e.g., a crossing wire, is advanced along the lumen of the LA catheter, puncturing the GCV wall, and then advanced into the magnetic channel of the GCV catheter within the GCV. Next, as shown in Figure 40, a pusher tube is used to advance a posterior T-bar anchor across the punctured tissue and into the magnetic head of the GCV catheter. Next, as shown in Figure 41, the crossing wire is removed by withdrawing it through the lumen of the LA catheter. Next, as shown in Figure 42, the LA catheter is removed, and the GCV catheter is advanced into the GCV to position the posterior T-bar anchor and suture bridge, as shown in Figure 43. The suture bridge is then tensioned and the GCV catheter is withdrawn from the GCV, thereby completing the implantation procedure, leaving the posterior T-bar anchor in the GCV, as shown in Figures 44 and 45.

[0098] 46-48, in some embodiments, the penetrating member is advanced from outside to inside (LA to GCV). As shown in FIG. 46, a posterior T-bar anchor is delivered to a target site within the GCV via a GCV catheter, and the magnetic heads of the LA and GCV catheters are magnetically coupled.

[0099] In various embodiments, the penetrating member is a pusher shaft with a removable screw tip that is advanced through the LA catheter from the left atrial side. The removable screw tip is also attached to a suture bridge. During implantation, the screw tip is advanced on the pusher shaft along the LA catheter, through the left atrial wall, and threaded into the side of the posterior anchor residing in the groove of the GCV catheter magnet, as shown in Figures 47 and 48. The pusher shaft is then removed from the screw tip and backed out of the LA catheter, leaving the suture bridge attached to the posterior anchor via the screw tip. The LA catheter is then withdrawn, the GCV catheter is withdrawn, and the posterior anchor is implanted. For simplified crossing, multiple bridges can be easily deployed in a short time. Pairing powerful magnets (high counter-traction force) improves the ability of the penetrating guidewire to advance and thread into the posterior anchor. In some embodiments, the posterior anchor itself has a side slot into which the screw tip can connect. It is also envisioned that the posterior anchor may be constructed of rubber, silicone, or a polymeric material into which the screw tip can easily thread. Once the screw tip is connected to the posterior anchor, the control guidewire is removed from the screw tip and remains behind the suture bridge.

[0100] As discussed herein, Figures 37-45 further illustrate the use of the magnetic catheter system of the present invention in a procedure to advance a penetrating member (e.g., a crossing wire) from the left atrium into the GCV and advance a posterior anchor from the left atrium into the GCV.

[0101] It should be appreciated that the magnetic catheter system of the present invention (shown in FIGS. 37-45) provides an alternative means for delivering a posterior anchor to the GCV. In practice, a GCV magnet catheter, e.g., a first catheter, and an LA catheter, e.g., a second catheter, are delivered as discussed herein, and a magnetic connection is made across the left atrial wall with the intended crossing / puncture site just above the P2 mitral valve leaflet. A penetrating member, e.g., a crossing wire, is delivered from the LA magnet catheter and penetrates toward / inward of the tip of the GCV magnet catheter. In some embodiments, the GCV catheter is shaped to accept the crossing wire tip and deflect it proximally down the catheter shaft. A posterior anchor, such as a T-bar, is advanced down the crossing wire from the LA catheter. In one embodiment, the crossing wire and T-bar can be coaxial with the LA catheter's magnet (as the magnet cross-section allows), or they can be parallel. The distal end of the T-bar has a tapered tip that penetrates the crossing hole, allowing the T-bar to be pushed into the hole. In some embodiments, there is a pusher tube behind the T-bar that pushes the T-bar across the hole. Once the T-bar has passed through the hole, the pusher tube can be retracted and removed. The crossing wire is removed by either backing it out of the femoral access or by advancing the piercing end to the jugular venous access site and then withdrawing the wire from there. In this procedure, the GCV catheter is advanced forward (towards the AIV) or the T-bar is pushed a small distance (approximately the length of the T-bar). 1 / 2) A means of advancement is provided, and the bridge element is tensioned from the septal side so that the T-bar attachment point is directly below the transverse foramen. The two magnetic catheters are then completely removed from the patient.

[0102] It will be appreciated that this system and procedure simplifies the manner in which posterior anchors are delivered compared to conventional delivery methods. In particular, the need to deliver a loop of suture (which requires a cassette to feed the loop) is eliminated. Additionally, a steerer tube is not required. It will further be appreciated that this procedure can be used to deliver multiple posterior anchors without having to remove and replace the GCV catheter each time.

[0103] Catheter configuration As previously discussed, one purpose of some such delivery catheter configurations is to combine magnets to maintain the posterior anchor on one delivery catheter within the great cardiac vein, thereby facilitating deployment of the posterior anchor while keeping the bridging elements entirely within the protection of the magnetically connected catheter. Examples of such delivery catheter configurations are detailed below. It will be understood that any of the aspects or features described in a particular embodiment may be utilized in various other embodiments in accordance with the concepts described herein.

[0104] 17-19 illustrate anchor delivery catheter configurations according to embodiments of the present invention. In particular, the catheter configurations magnetically couple with corresponding catheters to establish access into a cardiac chamber from the adjacent vasculature, enabling delivery of a cardiac implant according to embodiments of the present invention. These exemplary delivery catheters are configured for use within a GCV catheter 50 within the exemplary delivery and deployment method illustrated above. It will be understood that the following catheter configurations may include any of the various aspects (e.g., length, material, dimensions, etc.) described herein, but are not limited to the aspects described herein, and may be configured as needed for a particular use or anatomical structure.

[0105] FIG. 17 shows a distal portion of a delivery catheter configuration 700 including a longitudinally extending guidewire lumen 701a to facilitate advancement of the catheter along a guidewire 1 positioned within a patient's vasculature (e.g., within the great cardiac vein when the catheter configuration is utilized in a GVC anchor delivery catheter). The catheter may further include a puncture wire lumen 701b sized to allow passage of a puncture wire and subsequent passage of a bridge element 12 attached thereto. The catheter includes a magnetic head 702 configured to magnetically couple with a magnetic head 722 of a corresponding catheter 720 through a tissue wall therebetween. The magnetic head 702 is defined such that its magnetic poles are disposed transversely to the longitudinal axis of the catheter so as to couple vertically with the magnetic head 722 of the magnetic catheter 720 in a manner similar to FIG. 11C . The magnetic head 702 further includes a guide channel 703 defined to steer the puncture guidewire 54 upward through an exit hole 704 on one side of the magnetic head 702 and direct the sharpened distal tip 55 (e.g., a flat tip) of the puncture guidewire 54 through the tissue wall and into the magnetic head 722 of the catheter 720. The magnetic head 722 is defined by a central channel that is funnel-shaped to direct the puncture wire 52 into the central channel. The dashed vertical lines in FIGS. 17-19 represent points at which the delivery catheter extends outside the body. In any of these embodiments, the guidewire 1 and bridge element 12, as well as the puncture wire 54, extend through a Y-arm connector, facilitating independent manual control of the guidewire 1 and puncture wire 54 / bridge element 12. (The catheter shaft extending between the distal end portion and the Y-arm connector is not shown.) In such embodiments, the length of the puncture wire 54 is longer than the combined length of both magnetic catheters, and the length of the bridge element 12 is at least long enough to extend from the posterior anchor to the second access site, so that when the puncture wire is withdrawn from the second access site, the bridge element is withdrawn from the second access site. In some embodiments, the bridge element (suture) may be long enough to remain outside the first access site until it is withdrawn from the second access site.This may be desirable in the unlikely event that the suture is severed from the puncture wire before it is withdrawn from the second access site, allowing the operator to retrieve it by pulling on the proximal portion that is still outside the body. In this case, it would need to be as long as the combined length of the second catheter 60 and twice the length of the delivery catheter 50, due to the need to switch back as described above. It will be understood that while the delivery catheter configuration shown in FIG. 17 extends from right to left, the ends of the catheters extend from left to right when viewed from the front of the patient, as shown in FIG. 13.

[0106] The catheter 700 includes a catheter shaft 705 along its length, which may be formed of any suitable material to facilitate advancement of the catheter through the vasculature. As shown, the magnetic head 702 is formed with a notch or curved recess on one side, which in this embodiment is opposite the exit hole 704, but in embodiments may be located in any suitable location. The notch, recess, or groove 709 is configured to allow passage of the guidewire 1 and / or to receive at least a portion of the posterior anchor 718. In this embodiment, the posterior anchor 718 is defined as an elongated member having a longitudinal lumen through which the guidewire 1 extends. It will be understood that a posterior anchor having a longitudinal lumen through which the guidewire 1 extends may be utilized in any of the embodiments described herein. It will be further understood that the rear anchor 718 can be positioned extending partially within the recess in the magnetic head, extending distally (as shown) or proximally of the magnetic head, or extending proximally and proximally and distally of the magnetic head (as shown in FIG. 20), or can be disposed completely proximally or completely distally of the magnetic head (as shown in FIG. 21).

[0107] An outer jacket 706 covers the magnetic head 702 and includes an opening over the exit hole 704 to allow passage of the penetrating guidewire 54. Typically, the outer jacket 706 is formed of a flexible polymeric material and is defined to form a smooth interface with the catheter shaft 705. The outer jacket helps to maintain the magnetic head 702 within the catheter and may extend at least partially over the rear anchor 718 to help retain the rear anchor 718 during advancement of the catheter through the vasculature. Optionally, a polymeric rounded tip 707 may be provided at the distal end of the jacket to facilitate advancement of the catheter through the vasculature.

[0108] 18 shows a distal portion of a delivery catheter configuration 800 in a patient's vasculature, including a longitudinally extending guidewire lumen 801 to facilitate advancement of the catheter over a guidewire 1 positioned within the great cardiac vein when the catheter configuration is utilized in a GVC anchor delivery catheter. The catheter may further include a puncture wire lumen 801b sized to allow passage of a puncture wire 54 and subsequent passage of a bridge element 12 attached thereto. The catheter includes a magnetic head 802 contained within an inner jacket 803 configured to magnetically couple with a magnetic head of another catheter on the opposite side of the tissue wall, as described in other embodiments. The magnetic head includes a guide channel (not shown) for directing the puncture guidewire 54 through an exit hole 804 on one side of the magnetic head and into the lumen of the other catheter when magnetically coupled. The inner jacket 803 includes an opening above the exit hole 804 to allow passage of a sharpened distal end 55 (e.g., a flat tip) of the puncture guidewire 54. As shown, posterior anchor 818 is defined as an expandable scaffold. Here, the expandable scaffold is self-expanding and constrained within the configuration shown by constraining sheath 806 (shown as transparent to improve visibility of the underlying components). Proximal retraction of constraining sheath 806 allows expandable scaffold posterior anchor 818 to expand and release from inner jacket 803. Bridge element 12 is attached to the proximal end of puncture guidewire 54 and extends through exit hole 804 on the outside of the inner jacket back to reinforcing ribs 819 on posterior anchor 818 so that bridge element 12 passes through the exit hole and across the heart chamber, and once posterior anchor 818 is deployed, catheter 800 can be withdrawn from within deployed posterior anchor 818, allowing the implantation process to proceed with deployment of the anterior anchor as described above. In some embodiments, deployment may further involve laterally collapsing the scaffold by tensioning bridge element 12.

[0109] FIG. 19 shows a distal portion of a delivery catheter configuration 900 in a patient's vasculature, including a longitudinally extending guidewire lumen 901a to facilitate advancement of the catheter along a guidewire 1 positioned within the great cardiac vein when the catheter configuration is utilized in a GVC anchor delivery catheter. The catheter may further include a puncture wire lumen 901b sized to allow passage of a puncture wire 54, a length of bridge member extending to a pre-loaded posterior anchor, and, in some embodiments, a tether release wire. The catheter includes a magnetic head 902 (not shown) contained within an outer jacket 906, which is configured to magnetically couple with the magnetic head of another catheter, as described above. The magnetic head includes a guide channel (not shown) for guiding the puncture guidewire 54 through the exit hole 904 and into the lumen of the other catheter when magnetically coupled. The outer jacket 906 includes an opening above the exit hole 904 to allow passage of the sharpened distal end 55 of the puncture guidewire 54 through the exit hole 904. As shown, the posterior anchor 918 is defined as a non-expandable scaffold. The scaffold can be secured in place by a releasable coupling, such as a suture or tether 903, extending from inside the lumen of the catheter to its proximal end, such that removal of the tether releases the scaffold. Release can be further facilitated by gently pulling on the bridge element 12 advanced through the other magnetically coupled catheter. The catheter 900 can then be retracted, and the implantation process can proceed with deployment of the anterior anchor, as described above. In some embodiments, deployment can further involve laterally collapsing the scaffold by pulling on the bridge element 12.

[0110] 20 shows the distal portion of a delivery catheter configuration 1000 having a magnetic head 1002 and a rear anchor 1018 disposed on a guidewire 1 along which the catheter is advanced through the vasculature. In this embodiment, the rear anchor 1018 is axially "stacked" and sits within a groove 1009 defined in the magnetic head so that it completely overlaps the magnetic head. The magnetic head includes a side hole 1004 through which a through-guidewire can be advanced and from which a bridge element 12 extends and can be attached to the rear anchor 1018 at an attachment mechanism 1012. The rear anchor includes a central portion 1018a that is substantially rigid and includes the attachment mechanism 1012, and strain relief portions 1018b at each end that allow bending so that the distal portion of the catheter has some flexibility to accommodate curvatures in the vasculature through which it is advanced. In this embodiment, the system includes a reinforced guidewire lumen 2 (e.g., a braided or coiled wire lumen) to facilitate advancement of the posterior anchor and prevent kinking when advanced along a curved path. The outer jacket 1006 extends over the magnetic head and includes an opening over the exit hole 1004, and may include a distal tapered portion 1007 having an opening through which the posterior anchor 1018 can be deployed. As described above, once the bridge element is delivered through a second catheter magnetically coupled to the delivery catheter, the posterior anchor 1018 can be released by withdrawing the guidewire 1 and guidewire lumen 2, which can be further facilitated by gently pulling on the bridge element 12 advanced through the other magnetically coupled catheter. In some embodiments, the posterior anchor 1118 can be further secured by a releasable coupling mechanism and released by retracting the tether, as described above.

[0111] The previously described non-stented "hypotube" posterior anchor deployment catheter with a dedicated guidewire lumen relies on a bridge attachment location on the anchor to be aligned and placed on the delivery catheter at or very near the exit hole of the puncture wire within the magnet. One recognized advantage of such a delivery catheter design is that the anchor is at or directly adjacent to the puncture site at the time of puncture and does not need to be repositioned before being released from the catheter. One disadvantage associated with such a design is the increased profile, bulk, and stiffness of this distal staked catheter element. While preferred, designs in which the posterior anchor is placed within or partially within the magnetic portion of the delivery catheter may not always be ideal, as this compromises the ability to advance the distal portion of the delivery catheter around curves and torque the catheter in small vasculature, particularly the great cardiac veins. Another disadvantage is that in past designs, some magnet bulk was removed to maintain a relatively reduced profile for the anchor, reducing magnetic strength. This can make alignment with and attachment to the mating catheter more skill dependent and require more catheter manipulation. To further reduce the delivery profile and increase flexibility without loss of magnetic energy, some preferred embodiments of the delivery catheter utilize an anchor that is axially offset from the magnetic head along the longitudinal axis of the catheter, as shown, for example, in FIG.

[0112] FIG. 21 illustrates an exemplary delivery catheter configuration 1100 having a magnetic head 1102 and a rear anchor 1118 that is axially offset from the magnetic head 1102 along the longitudinal axis of the catheter so as not to overlap the magnetic head. The rear anchor 1118 is disposed over a guidewire 1 along which the catheter is advanced through the vasculature. In this embodiment, the magnetic head 1102 includes a smaller groove 1109 defined therein through which the guidewire lumen 2 extends. The magnetic head includes a side hole 1104 through which a through-guidewire can be advanced and from which a bridge element 12 extends and can be attached to the rear anchor 1118 at an attachment mechanism 1112. The rear anchor includes a central portion 1118a that is substantially rigid and includes the attachment mechanism 1112, and strain relief portions 1118b at each end that allow bending so that the distal portion of the catheter has some flexibility to accommodate curvatures in the vasculature through which it is advanced. The strain relief portion 1118b is defined as a helical cut within the elongate tube that defines the posterior anchor 1118. In this embodiment, the system includes a reinforced guidewire lumen 2 (e.g., a braided or coiled wire lumen) to facilitate advancement of the posterior anchor and prevent kinking when advanced along a curved path. The outer jacket 1106 includes an opening over the exit hole 1104 and may include a distal tapered portion 1107 with an opening that surrounds the proximal portion and lumen extension 1108 of the posterior anchor 1118. As described above, when the bridge element is pulled through a second catheter magnetically coupled to the delivery catheter, the posterior anchor 1118 can be released by withdrawing the guidewire 1 and guidewire lumen 2, which can be further facilitated by gently pulling on the bridge element 12 advanced through the other magnetically coupled catheter. In some embodiments, the rear anchor 1118 may be further secured by a releasable coupling mechanism, for example, a tether or tether loop that is released by engaging the rear anchor with a distal portion of the catheter and retracting the tether, as described above.

[0113] A key feature that reduces the profile and increases flexibility is the placement of a posterior anchor in front of the magnet and over the guidewire. This design takes advantage of the natural bending properties of the proximal portion of the two intact ends (e.g., strain relief portions) of the posterior anchor design to create a bending point (see arrows in FIG. 21 ), allowing the distal portion to bend or flex relative to the magnetic head portion (see dotted line) to better approximate the curve of a body cavity or vasculature, such as the GCV. Compared to the larger catheter magnet tip profile section described above in FIG. 20 , the posterior anchor at the tip of the delivery catheter in FIG. 21 better approximates the natural reduced diameter of the vasculature as the catheter is delivered and advanced distally.

[0114] Because bending is concentrated at a point between the semi-rigid sections, transitional features can be added to aid translational and rotational performance during deployment and to inhibit kinking or guidewire binding at the joint. At the inner diameter, a reinforced guidewire lumen 2 (e.g., braided or coiled wire) spanning the entire length of the catheter can be used to facilitate advancement of the rear anchor. In some embodiments, the reinforced guidewire lumen is sized to substantially fill the luminal space between the guidewire and the rear anchor. An outer flexible polymer lumen extension 1108 provides a gradual transition in bending of the distal portion of the catheter around the anchor, which terminates at the attachment point of the bridge element. At the outer diameter before the magnet, a distal tapered portion 1107 is defined as a flexible conical section to limit the amount of bending above the bending point and can act as a smooth transition against the vasculature wall, accommodating the different diameters of the magnetic head and rear anchor cross-sections.

[0115] Both designs shown in Figures 20-21 allow for delivery of a hollow posterior anchor within a magnetically connected delivery catheter, primarily without exposing a suture bridge to the tissue.

[0116] In some embodiments, a releasable bond, such as a tether connected to the proximal end of the delivery catheter, holds the posterior anchor in place during deployment and releases it when in place. A stacked design, in which the posterior anchor partially or completely overlaps the magnetic head, has the advantage of one-step deployment and delivery, but bulk and stiffness limit distal prolapse into smaller vasculature, and the design may be more difficult to construct. An offset design, in which the posterior anchor is offset (e.g., distal or proximal to the magnetic head), allows for deeper passage into the vessel, especially into smaller vasculature, and is easier to construct; however, an additional repositioning step for anchor delivery may be required after the initial traverse, exposing a short section of suture to which the magnet is not attached.

[0117] In some embodiments, the catheter may include one or more radiopaque markers to aid in translational and rotational alignment of the delivery catheter and to facilitate magnetic coupling to the mating catheter. It may be desirable to align the side hole in the magnetic head of the first catheter with the opening in the second catheter before magnetic coupling, as this allows for a more consistent and robust magnetic coupling and minimizes skill-dependent manipulations to align the catheters. In some embodiments, the catheter includes two radiopaque markers that are asymmetric in shape and / or position relative to the longitudinal axis of the respective catheters to indicate the rotational orientation of the catheter and facilitate alignment of the side hole opening in the magnetic head of the catheter with the corresponding lumen opening in the second catheter. For example, the one or more markers may include a first marker on the side of the catheter opposite the side hole and a second marker on the same side as the side hole, the second marker differing in relative position and / or size to be easily distinguished from the first marker and to aid in determining rotational orientation. It will be understood that these marker schemes may be used with any of the catheter embodiments described herein.

[0118] 22A shows one such system having a first catheter 1201 and a second catheter 1210, where the first catheter 1201 has a magnetic head 1202 (e.g., a single magnet, a dual magnet, or a triple magnet) with a side hole opening 1204, and the second catheter 1210 has a distal opening 1214 aligned with the side hole opening 1204 for passage of a feedthrough wire therethrough to establish access between the catheters. The first catheter includes two radiopaque markers 1205a, 1205b that are asymmetric about the longitudinal axis of the first catheter, allowing a user to easily determine the rotational orientation of the first catheter before the catheters are approximated and magnetically coupled. In this embodiment, the marker closest to the side hole (marker 1205a) extends further proximally so that it is easily distinguishable from the opposing marker 1205b so that the rotational orientation of the first catheter and the relative alignment of the catheters can be easily determined, as can be seen in the fluoroscopic image shown in FIG. 22B, which illustrates a system with such markers. While the markers shown are substantially rectangular and positioned as shown, it will be understood that various other sizes, shapes, and positions of markers can be utilized in the same manner. For example, angled lines pointing to the side hole, triangles, and other shapes and sizes can be used to help indicate orientation and rotation. Furthermore, it will be understood that the magnetic head is also visible under fluoroscopy so that the second catheter does not require a separate radiopaque marker.

[0119] 23 illustrates an exemplary method of delivering and deploying an implant using a catheter system according to an embodiment of the present invention. The method includes advancing a first catheter from a first vascular access point along a first vascular pathway into a heart vessel, the first catheter having a distal magnetic head adjacent to a first anchor, and advancing a second catheter from a second vascular access point along a second vascular pathway into a heart cavity, the second catheter having a distal magnetic head. The first and second catheters are then positioned to magnetically couple the distal magnetic heads across a tissue wall between the heart cavity and the blood vessel. A puncture guidewire is then advanced from the first catheter into the second catheter while magnetically coupled, thereby penetrating the tissue wall. The puncture guidewire is advanced to exit the second vascular access point, and the attached bridge element coupled to the first anchor is pulled across the heart chamber, and the guidewire is pulled until it exits at the second vascular access point while the first and second catheters are magnetically coupled. The first anchor is then deployed from the first catheter, and the first catheter is removed. One or more additional anchors can then be attached to one or more other portions of the bridge element that extend across the heart chamber or through the associated vasculature, as needed for deployment of the particular type of implant.

[0120] In some embodiments, it may be desirable to displace or remove the implant after deploying and removing any tension and obstruction, thereby allowing access to the mitral valve and surrounding tissue. For example, in some patients, the implant may prove ineffective or may require the implementation of another type of implant or procedure (e.g., endovascular valve replacement). Therefore, methods and devices that allow for subsequent removal of the implant are desirable. Removal, or at least partial removal, can be achieved by severing the bridging elements. The posterior anchor can be removed using conventional catheter techniques, or in some embodiments, can be left in place within the great cardiac vein. The septal anchor typically presents no problems and can be left in place. Examples of such devices for severing the bridging elements of an implant are shown in Figures 24A-26B.

[0121] 24A-24C illustrate a bridge cutting catheter 210 for facilitating removal of a deployed implant, such as any of the implants described herein, in accordance with an embodiment of the present invention. The bridge cutting catheter 210 includes a curved-tip stylet 211 within the inner diameter of the catheter shaft to facilitate steering the cutting tip toward the suture bridge 12. The cutting tip includes a cutting blade 212 and a capture mechanism 213. The cutting blade 212 includes a sharpened cutting edge along one longitudinally extending side and an angled, proximally facing end face. The capture mechanism 213 is a loop that is angled to capture the bridge elements 12 and orient them toward the cutting edge when the cutting catheter is retracted proximally. Because the bridge elements 12 are under tension within the deployed implant, this approach is advantageous for capturing and cutting the bridge elements 12 with limited visualization. Furthermore, the loop shape prevents the cutting edge from contacting delicate cardiac tissue during the procedure. In some embodiments, the cutting catheter is advanced within a sheath. For example, a cutting catheter can be advanced within an 8-10F Mullins sheath placed within the LA across the septal wall near the periphery of the anterior anchor after conventional percutaneous septal resection. Some anterior anchor types allow a delivery catheter to pass through them due to flexible or soft lower components or pre-constructed fenestrations.

[0122] As shown in Figure 24A, after the cutting tip has been advanced from the Mullins catheter, the bridge-cutting catheter 210 is positioned over the tension bridge element 12 of the deployed implant and retracted proximally to capture the bridge element 12 with the capture loop. Once the bridge element is captured, as shown in Figure 24B, further retraction of the bridge-cutting catheter forces the bridge element upward along the angled proximally-facing end face of the blade and along the cutting edge, thereby severing the bridge element, as shown in Figure 24C.

[0123] While the presence of cut bridge elements 12 is rarely problematic, it may be desirable to substantially remove the remaining bridge elements 12, for example, to prevent flail sutures from entering the annulus and potentially interfering with placement of the valve replacement. In such cases, it may be desirable to use a tool that allows for cutting and removal of a significant portion, or at least a majority, of the bridge elements.

[0124] FIG. 25 illustrates a bridge cutting catheter with a suture grip 220 for severing the bridge elements and removing excess suture after severing, according to an embodiment of the present invention. Similar to the bridge cutting catheter of FIGS. 24A-24C, this catheter includes a cutting head with a cutting blade 222 and a capture loop 223 configured and operative similarly to those described above. The catheter further includes a suture grip 224 to facilitate removal of excess suture. The catheter includes a steerable shaft 221 that allows the cutting tip to be steered relative to the bridge. In this embodiment, the shaft is dual-shaft, with one shaft supporting the cutting tip and the other supporting the suture grip 224 that holds the bridge element during the initial cut, thus maintaining the bridge element while rolling up excess suture grip to allow subsequent cutting and removal of the majority of the bridge element. The suture grip 224 may be configured to hold the bridge element (e.g., by friction fit or between opposable members) and roll up excess bridge element by rotation of an element extending through the catheter shaft.

[0125] As shown in FIG. 26A , the cutting catheter 220 is positioned adjacent the anterior anchor (not shown) and the locking bridge stop 30, and is positioned to capture the tensioned bridge element 12 with the capture loop 223 and hold the bridge element with the suture grip 224 (positioned further from the anterior anchor than the cutting blade 222). After initially cutting the bridge element 12 with the cutting element as described above, the suture grip 224 is actuated by rotation of a rotatable member extending through the shaft. This reels in excess suture and moves the cutting catheter adjacent the posterior anchor, as shown in FIG. 26B . Because the suture grip 224 holds the excess suture taut, a second cut can be made with the cutting tip, similar to that described above, thereby removing most of the bridge element. The excess suture is retained on the suture grip and removed upon removal of the cutting catheter.

[0126] System for Anatomical Vascular Insertion Depth As discussed herein, the insertion depth of the catheters of the present invention can be determined in several different ways. For example, components of the systems of the present invention can be constructed of materials that are radiopaque or incorporate radiopaque features to facilitate fluoroscopic visualization. However, it will be understood that insertion depth can also be determined without the use of fluoroscopic visualization.

[0127] Thus, in embodiments, the present invention provides a catheter system that allows for measuring the insertion depth of a catheter within an anatomical vessel. While the present disclosure illustrates the use of the system in cardiac surgery, it will be understood that the system may be utilized in any surgical procedure in which determining the insertion depth within an anatomical vessel is desirable. With reference to FIGS. 31 and 32 , a catheter system 1500 includes an elongated overtube 1510, a catheter 1520 slidably disposed within the lumen of the overtube, and a depth measurement mechanism 1530. In some aspects, the catheter 1520 includes a handle 1540 with a coupling 1550 that engages an elongated shaft 1560 of the measurement mechanism 1530. In various aspects, the depth measurement mechanism 1530 is slidably coupled to the handle 1540 via a coupling 1550 disposed at a proximal end of the mechanism 1530 and coupled to the overtube 1510 at a distal end of the mechanism. In some embodiments, mechanism 1530 is configured to measure movement of catheter 1520 along the lumen of overtube 1510 when the distal end of catheter 1520 is advanced distally relative to the distal end of overtube 1510 when expandable member 1570 of overtube 1510 is inflated within a blood vessel or at an entry point from a lumen to a blood vessel. In this manner, elongate shaft 1560 translates movement of catheter 1520 relative to overtube 1510 when the catheter is advanced distally or proximally within the lumen of the overtube.

[0128] In a related embodiment, the present invention provides a method for measuring insertion depth within an anatomical vessel using a catheter system of the present invention. The method includes advancing the catheter system of the present invention into the anatomical vessel. The inflation member is then expanded such that the overtube remains stationary within the vessel or relative to an entrance to the vessel within an external cavity, such as the right atrium. The method further includes advancing the distal end of the catheter distally relative to the distal end of the overtube and measuring, via a measurement mechanism, the distance the distal end of the catheter is advanced distally relative to the distal end of the overtube, thereby measuring the insertion depth of the catheter within the anatomical vessel.

[0129] During operation of a catheter system for use in a procedure to reshape the left atrium, the insertion depth of the catheter is determined by patient pre-screening. As shown in FIG. 33 , during subject pre-screening, the distance from the mitral valve opening to the P2 position (or a deeper position, if determined) that will be translated into the GCV is determined (see distance X). The practitioner then inserts the catheter into the right atrium via the jugular vein. Once in the right atrium, the practitioner performs the function of expanding the expandable member 1570. As the practitioner advances the catheter into the GCV, the expansion member 1570 contacts the opening / right atrial wall, and the catheter advances into the GCV, translating the insertion depth of the catheter into the GCV. While this occurs, a measuring mechanism on the catheter handle allows the practitioner to ensure that the correct positioning of the distal end of the catheter within the GCV for the procedure is achieved and that the puncture of the left atrial wall is in the correct location.

[0130] Treating mitral regurgitation As discussed herein, the systems and methods described herein are particularly useful for treating mitral valve regurgitation by reshaping a heart chamber, for example, by reshaping the left atrium. Thus, the present invention provides a method for treating mitral valve regurgitation in a subject by reshaping the subject's heart chamber using the systems described herein. In one aspect, the method utilizes first and second catheters as shown in FIG. 27 . The method includes inserting a first catheter 1300 through a first vascular access site and advancing the first catheter 1300 to a first location within or adjacent to the subject's heart. A second catheter 1310 is inserted through a second vascular access site and advanced to a second location within or adjacent to the heart, the first and second locations being separated by a cardiac tissue wall. The first catheter 1300 and the second catheter 1310 are then positioned such that the first magnet 1320 and the second magnet 1370 are magnetically coupled across the tissue wall. Next, while the first and second catheters remain magnetically coupled, the tissue wall is penetrated with a penetrating member, such as a penetrating guidewire, advanced through the first catheter 1300, across the tissue wall, and through the second catheter 1310. While the first magnet 1320 and the second magnet 1370 remain magnetically coupled, the posterior anchor and a bridge element coupled to the posterior anchor at a first end of the bridge element are advanced from the first vascular access site to a first location. The second end of the bridge element is advanced through the penetrated tissue wall and into the second catheter 1310. As shown in FIGS. 16A-16D , the anterior anchor is advanced along the bridge element from the second vascular access site and deployed at a third location within the heart, with the bridge element spanning a cavity of the heart. Thus, the length of the bridge element is shortened to reshape the heart cavity, and while the heart cavity is reshaping, the second end of the bridge element is coupled to the deployed anterior anchor such that the heart cavity remains reshaped.In some embodiments, the method further includes determining the depth of insertion of the first catheter and / or the second catheter via radiopaque markers disposed along the length of each of the catheters (shown in FIG. 30 ) prior to magnetic coupling of the first magnet and the second magnet.

[0131] Although the invention has been described with reference to the above examples, it will be understood that modifications and variations are encompassed within the spirit and scope of the invention. Accordingly, the invention is limited only by the following claims.

Claims

1. a) having a proximal end and a distal end; i) a first lumen extending longitudinally through the length of the first catheter; ii) a first magnet disposed along a distal portion of the first catheter, the first magnet including a first magnetic pole and a second magnetic pole; iii) a first guide channel disposed in the distal portion of the first catheter and extending along a first longitudinal axis, the first guide channel being coextensive with the first lumen and having a first side hole positioned proximally along the distal portion of the first catheter relative to the first magnetic pole; the first catheter comprising: b) having a proximal end and a distal end; i) a second lumen extending longitudinally through the length of the second catheter; ii) a second magnet disposed at the distal end of the second catheter, the second magnet including a third pole and a fourth pole; iii) a second guide channel disposed at the distal end of the second catheter and extending along a second longitudinal axis, the second guide channel being coextensive with the second lumen and having a second side hole adjacent to the second magnet; the second catheter comprising: Including, When the first magnet and the second magnet are magnetically coupled, the first side hole and the second side hole are aligned in a plane parallel to the first longitudinal axis and the second longitudinal axis, and the second side hole is oriented distally along the distal portion of the first catheter relative to the first side hole. A system for delivering a cardiac implant.

2. 2. The system of claim 1, wherein the first side hole and the second side hole are at an angle of approximately 90 degrees relative to one another when the first magnet and the second magnet are magnetically coupled.

3. 10. The system of claim 1, wherein when the first magnet and the second magnet are magnetically coupled, the distal portion of the first catheter and the distal end of the second catheter are at an angle of approximately 90 degrees relative to each other.

4. The system of claim 1 , wherein the first magnetic pole and the second magnetic pole are disposed perpendicular to the first longitudinal axis.

5. 2. The system of claim 1, wherein the third magnetic pole and the fourth magnetic pole are disposed parallel to the second longitudinal axis, and the third magnetic pole is distal along the distal end of the second catheter relative to the fourth magnetic pole.

6. The system of claim 1 , wherein the first magnetic pole and the third magnetic pole are adjacent to each other when the first magnet and the second magnet are magnetically coupled.

7. The second magnet is an arcuate or angled surface oriented toward and defining a surface of the second guide channel; a curved recess having The surface of the second guide channel is: When the first magnet and the second magnet are magnetically coupled, they guide a guide wire extending from the first guide channel through the second guide channel. It is configured as follows: The system of claim 1 .

8. The system of claim 7 , wherein the curved recess extends from a distal portion of the second magnet to a proximal portion of the second magnet.

9. a penetrating member or guidewire advanceable through the first and second guide channels via the first and second side holes when the first and second magnets are magnetically coupled; 8. The system of claim 7, further comprising: a penetrating member or guidewire having a sharpened distal end to facilitate penetration of tissue.

10. The system of claim 1 , further comprising a radiopaque marker disposed at the distal end of the first catheter or the second catheter.

11. The system of claim 10 , wherein the radiopaque marker is disposed at the distal end of the first catheter distal to the first magnet.

12. The system of claim 1 , wherein the first catheter comprises radiopaque markers disposed along the length of the first catheter for determining depth of insertion.

13. The system of claim 1 , wherein the second catheter comprises radiopaque markers disposed along the length of the second catheter for determining depth of insertion.

14. 2. The system of claim 1, wherein the first catheter includes one or more radiopaque markers disposed along the distal portion of the first catheter, the one or more radiopaque markers being asymmetrically positioned about the longitudinal axis of the first guide channel to facilitate alignment of the rotational orientation of the first catheter relative to the second catheter prior to magnetic coupling.

15. 15. The system of claim 14, wherein the one or more radiopaque markers comprise a first and a second marker, the first marker being disposed on the same side of the first catheter as the first side hole and being separate from the second marker under fluoroscopy.

16. A method for treating a vascular disease comprising: a) providing a vascular system including: an elongated overtube having a lumen, a proximal end, a distal end, and an expandable member disposed at the distal end; b) a catheter slidably disposed within the lumen, the catheter having a proximal end, a distal end, and a handle disposed at the proximal end of the catheter; c) a depth measurement mechanism slidably coupled to the handle at a proximal end thereof and coupled to the overtube at a distal end thereof, the mechanism configured to measure movement of the catheter along the lumen of the overtube when the distal end of the catheter is advanced distally relative to the distal end of the overtube when the expandable member is inflated; and A catheter system comprising: A catheter system, wherein the catheter is a first catheter according to any one of claims 1 to 15.

17. 1. A method for measuring insertion depth within an anatomical vessel, comprising: advancing the catheter system of claim 16 into the anatomical vessel; expanding an inflation member such that the overtube remains stationary within the vessel; advancing the distal end of the catheter distally relative to the distal end of the overtube; measuring via a measurement mechanism the distance the distal end of the catheter advances distally relative to the distal end of the overtube, thereby measuring the insertion depth of the catheter within the anatomical vessel; A method comprising:

18. 18. The method of claim 17, wherein the anatomical vessel is the great cardiac vein.

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