Cardiac load modulation systems and methods

Abstract

Cardiac load modulation systems and methods are disclosed for treatment of patients in congestive heart failure. Disclosed systems include dual occlusion, telescoping catheters allowing simultaneous or sequential occlusion in the superior vena cava and inferior vena cava to synergistically modulate heart pre-load on the right side of the heart and pressure difference in the kidneys as a potential treatment or management of acute decompensated heart failure (ADHF). Control algorithms and safety parameters for treatment with disclosed systems are also disclosed.

Description

CARDIAC LOAD MODULATION SYSTEMS AND METHODSRELATED APPLICATION DATA

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 63 / 644,994, filed on May 9, 2024, and U.S. Provisional Patent Application Serial No. 63 / 691,364, filed on September 6, 2024, each entitled “Cardiac Load Modulation Systems and Methods”. Each of these applications is incorporated herein by reference in its entirety.FIELD

[0002] The present disclosure generally relates to systems and methods for treatment of heart failure patients and more specifically to cardiac load modulation systems and methods for treatment of patients in congestive heart failure.BACKGROUND

[0003] Congestive heart failure (HF) is a growing epidemiologic problem and a significant source of morbidity, mortality, and healthcare expenditure. Approximately 5.1 million people in the United States carry a diagnosis of HF, and the prevalence continues to rise.

[0004] Acute decompensated heart failure (ADHF) is a clinical syndrome of worsening signs and symptoms of HF that often leads to hospitalization or an emergency department visit. Almost 33% of patients hospitalized are re-hospitalized within 60 to 90 days of discharge, and nearly 66% die or will be re-hospitalized within one year.

[0005] The pathophysiology of fluid retention in ADHF has been linked to managing heart preload on the right side of the heart and the pressure difference in the kidney between the arterial and venous sides. Given this linkage, various solutions have been proposed to manage preload and pressure difference across the kidneys as techniques for lessening negative impacts of congestive heart failure.

[0006] One such proposed solution is disclosed in U.S. Patent No. 10,363,044 to Tai et al., entitled “Blood Flow Reducer For Cardiovascular Treatment.” This disclosure proposes catheterbased devices for controlled partial occlusion of the Inferior Vena Cava (IVC) inferior to the renal veins as a method of altering blood flow to affect or alter cardiovascular preload or renal afterload as a treatment for hypervolemia in acute heart failure patients.

[0007] Another proposed solution is disclosed in U.S. Patent No. 9,393,384 to Kapur et al., entitled “Systems and Methods For Treating Acute and Chronic Heart Failure.” This disclosureproposes implantable devices for selective intermittent occlusion of the Superior Vena Cava (SVC) as a method of controlling return of venous blood to the right ventricle to lower diastolic pressures to improve cardiac function. This disclosure also suggests that selective intermittent SVC occlusion may avoid potential disadvantages associated with IVC occlusion, such as risk of venous congestion, and blockage or enlargement of the hepatic veins or suprarenal vein.

[0008] While various solutions have been proposed to modify or treat specific areas of cardiac function, each has proposed advantages and disadvantages, and there remains a need in the art for a more comprehensive solution that addresses in a single system a wider range of heart-failure-related parameters.SUMMARY OF DISCLOSURE

[0009] Disclosed embodiments address needs in the art by providing controllable systems and methods in which a host of physiological parameters are triaged, and a control algorithm is executed in which identified critical physiological parameters are tightly controlled while other subservient physiological parameters are optimized towards targets in a manner that operates within monitored physiological safety parameters.

[0010] In some aspects, the present disclosure is directed to a cardiac load modulation system, which includes an outer catheter body having a proximal end configured to reside outside of a patient and a distal end configured to be received in a patient’s vasculature; an inner catheter body slidably received within the other catheter body with a proximal end extending proximally with respect to the outer catheter body proximal end and a distal end extending distally with respect to the outer catheter body distal end; a first controllable vascular occlusion member disposed at the distal end of the inner catheter body; a second controllable vascular occlusion member disposed at the distal end of the outer catheter body; and first and second occlusion actuators configured to control a time and degree of vascular occlusion for the first and second controllable vascular occlusion members.

[0011] In one or more embodiments of the cardiac load modulation system, the system includes pressure sensors disposed on the catheter bodies distally and proximally with respect to each controllable occlusion member.

[0012] In one or more embodiments of the cardiac load modulation system, the system includes a processing system controlling first and second occlusion actuators and receiving pressure inputs from the pressure sensors.

[0013] In one or more embodiments of the cardiac load modulation system, the processing system executes a control algorithm comprising repeating, alternating, sequenced occlusion and relief times for the occlusion balloons.

[0014] In one or more embodiments of the cardiac load modulation system, the first and second controllable vascular occlusion members comprise occlusion balloons.

[0015] In one or more embodiments of the cardiac load modulation system, the first and second occlusion actuators each comprise an inflation pump communicating with each occlusion balloon through the respective catheter bodies.

[0016] In one or more embodiments of the cardiac load modulation system, at least one occlusion balloon comprises a compliant balloon.

[0017] In one or more embodiments of the cardiac load modulation system, at least one occlusion balloon comprises a multi-lobe occlusion balloon defining reduced flow path between lobes of the balloon when inflated.

[0018] In one or more embodiments of the cardiac load modulation system, at least one occlusion balloon comprises a spiral occlusion balloon defining a reduced flow path through a center of the spiral balloon when inflated.

[0019] In one or more embodiments of the cardiac load modulation system, at least one of the first and second controllable occlusion members comprises a mechanically expandable metal mesh structure with a covering to prevent blood flow when expanded.

[0020] In one or more embodiments of the cardiac load modulation system, the occlusion actuator controlling the mechanical expandable metal mesh structure comprises two relatively moveable control members at an outer hub of the catheter system.

[0021] In one or more embodiments of the cardiac load modulation system, one controllable occlusion member is configured for placement in and occlusion of a patient’s inferior vena cava (IVC) and one controllable occlusion member is configured for placement in and occlusion of the patient’s superior vena cava (SVC).

[0022] In some aspects, the present disclosure is directed to a method of cardiac load modulation, which includes intermittently occluding a patient’s superior vena cava (SVC) alternating between an SVC occlusion time and an SVC relief time with reduced SVC occlusion; intermittently occluding the patient’s inferior vena cava (IVC) alternating between an IVCocclusion time and an IVC relief time with reduced IVC occlusion; and controlling the intermittent occluding of the SVC and IVC sequentially such that the SVC occlusion time at least substantially aligns with the IVC relief time and the IVC occlusion time at least substantially aligns with the SVC relief time.

[0023] In one or more embodiments of the method, the controlling comprises occlusion times to partially overlap with relief times.

[0024] In one or more embodiments of the method, intermittently occluding the SVC and IVC comprises controlling expansion and contraction of occlusion members disposed in the SVC and the IVC.

[0025] In one or more embodiments of the method, the method delivers a catheter system into the patient’s vasculature, the catheter system including an SVC occlusion member and an IVC occlusion member.

[0026] In one or more embodiments of the method, the method positions the SVC occlusion member in the SVC and positions the IVC occlusion member in the IVC inferior of the renal arteries; and adjusts a length of the catheter system between the SVC and IVC occlusion members in accordance with the positioning of the occlusion members.

[0027] In one or more embodiments of the method, the positioning of the SVC occlusion member in the SVC comprises placement of the SVC occlusion member below the confluence of the left and right brachiocephalic veins.

[0028] In one or more embodiments of the method, the method includes, prior to intermittently occluding the SVC and the IVC, determining a full occlusion diameter for the SVC occlusion member and a full occlusion diameter for the IVC occlusion member.

[0029] In one or more embodiments of the method, determining the full occlusion diameter for the SVC occlusion member comprises identifying an inflection in right atrial pressure (RAP) while increasing the diameter of the SVC occlusion member and correlating the diameter of the SVC occlusion member at the RAP inflection with the full occlusion diameter of the SVC occlusion member; and determining the full occlusion diameter for the IVC occlusion member comprises identifying an inflection in infrarenal pressure while increasing the diameter of the IVC occlusion member and correlating the diameter of the IVC occlusion member at the infrarenal pressure inflection with the full occlusion diameter of the IVC occlusion member.

[0030] In one or more embodiments of the method, the method includes determining a partial occlusion diameter for the IVC occlusion member.

[0031] In one or more embodiments of the method, determining the partial occlusion diameter for the IVC occlusion member includes determining a target RAP by fully occluding the SVC for a predetermined time period and designating measured RAP at the end of the predetermined time period as the target RAP; and increasing IVC occlusion with no SVC occlusion while measuring RAP and setting the partial occlusion diameter for the IVC as the diameter of the IVC occlusion member at the target RAP.

[0032] In one or more embodiments of the method, the method includes controlling the SVC occlusion member to be at the full occlusion diameter for the SVC occlusion time; controlling the IVC occlusion member to be at a low partial occlusion diameter for the IVC relief time substantially corresponding to the SVC occlusion time; controlling the IVC occlusion member to be at a high partial occlusion diameter for the IVC occlusion time; and controlling the SVC occlusion member to be fully contracted for the SVC relief time substantially corresponding to the IVC occlusion time.

[0033] In one or more embodiments of the method, the occlusion members comprise occlusion balloons and the occlusion diameters are measured as balloon inflation volumes.BRIEF DESCRIPTION OF DRAWINGS

[0034] For the purpose of illustrating the disclosure, the drawings show aspects of one or more embodiments of the disclosure. However, it should be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:FIG. 1 is a schematic depiction of a system for cardiac load modulation deployed in a patient anatomy according to an embodiment of the present disclosure;FIG. 2 is a schematic depiction of an alternative embodiment of a system for cardiac load modulation deployed in the patient anatomy according to the present disclosure;FIG. 3 is a perspective view of an embodiment of a system for cardiac load modulation according to the present disclosure;FIG. 4 is a side view of a dual balloon, telescoping catheter according to an embodiment of the present disclosure;FIG. 5 is a top view of the telescoping catheter in FIG. 4;FIG. 6 is a cross-sectional view at section D-D of FIG. 4;FIG. 7 is a cross-sectional view of a catheter inner shaft according to embodiments of the present disclosure;FIG. 8 is a cross-sectional view of a catheter outer shaft according to embodiments of the present disclosure;FIG. 9 is a detail perspective view of the telescoping catheter in FIG 4;FIG. 10 is a perspective view of first and second multi-lobe occlusion balloons according to an embodiment of the present disclosure;FIG. 11 is an end view of a further embodiment of a multi-lobe occlusion balloon according to an embodiment of the present disclosure;FIG. 12 is a perspective view of a spiral occlusion balloon according to another embodiment of the present disclosure;FIG. 13 is another perspective view of a spiral occlusion balloon disposed in a vessel at a treatment location according to an embodiment of the present disclosure;FIG. 14 is a schematic side view of a braided wire or laser cut tube occlusion element in a collapsed or as delivered state according to embodiments of the present disclosure;FIG. 15 is a schematic side view of a braided wire or laser cut tube occlusion element in an expanded or occluding state according to embodiments of the present disclosure;FIG. 16 is a schematic perspective view of a braided wire or laser cut tube occlusion element in a partially expanded or partly occluding state disposed in a vessel at a treatment location according to embodiments of the present disclosure; andFIGS. 17A, 17B and 17C illustrate an embodiment of a control algorithm for cardiac load modulation systems according to the present disclosure.DETAILED DESCRIPTION

[0035] The present disclosure is directed to cardiac load modulation systems and methods that utilize controlled and coordinated simultaneous or sequential partial occlusion of both the SVC and IVC in order to assist in heart failure management and increase cardiac function with reduced potential risks associated with prior techniques and systems. “Partial occlusion” as used hereinrefers to an overall reduction in flow, which may be achieved by techniques in which blood flow is fully prevented on an intermittent basis or in which the vessel is only partially blocked to allow continuous reduced flow, as well as techniques that include intermittent partial blockage of flow, or any combination thereof.

[0036] FIGS. 1 and 2 illustrate embodiments of systems according to the present disclosure. In FIG. 1, system 10 includes outer catheter shaft 12 configured to be introduced through the jugular vein, with superior occlusion element 14 disposed at the distal end of the outer catheter shaft. Inner catheter shaft 16 extends through outer catheter shaft 12 and is configured to extend into the IVC terminating with inferior occlusion element 18. At least four pressure sensors 20 are provided above and below superior occlusion element 14 and above and below inferior occlusion element 18. FIG.2 illustrates an alternative embodiment, system 10A, configured for femoral introduction. In this embodiment outer catheter shaft 12A is adapted to be fem orally introduced and advanced up into the IVC. Outer catheter shaft 12A includes inferior occlusion element 18 and, in this case, inner catheter shaft 16 includes superior occlusion element 14. In some embodiments, occlusion elements 14 and 18 may be provided in the form of conventional occlusion balloons. In other embodiments, as described herein below, other configurations for the occlusion elements may be provided.

[0037] Disclosed systems provide means for maintaining a therapeutic but safe flow restriction. Any degree of occlusion (full to partial) could be cycled intermittently to allow the appropriate amount of passage of blood. As an example, if the SVC is fully occluded, blood pressures in the head could rise causing a serious clinical issue. Cycling between full occlusion / no occlusion for a period of 30 seconds on, 30 seconds off may prevent a pressure rise while still lowering the preload on the heart. Alternatively, partial occlusion (where some flow is still allowed to pass) for a period of 5 minutes on, 1 minutes off may also provide a therapeutic lowering of pre-load on the heart without causing a rise in cerebral pressures. Similarly, controlled cyclical IVC occlusion may be used to lower renal afterload with beneficial effect, and in some cases potentially also provide a benefit in reduction of cardiac preload. Together these two processes as described herein may offer complementary and synergistic beneficial effects not previously available with prior systems. System controls can be set to control inflation based of either time or physiological inputs like pressures as described herein.

[0038] FIG. 3 illustrates an embodiment of a cardiac load modulation system according to the present disclosure configured as implantable system 30 with occlusion catheters and occlusion elements introduced via the jugular vein into the SVC and IVC. As illustrated therein, outercatheter shaft 32 has hub 36 at its proximal end and superior vena cava occlusion balloon 34 at its distal end, and defines multiple lengthwise lumens as explained below. Inner catheter shaft 38 is configured for telescopic sliding within a lumen of outer catheter shaft 32, and has proximal hub 42 and distal inferior vena cava occlusion balloon 40. Inner catheter shaft 38 also defines multiple lengthwise lumens as defined below. Luer lock or other suitable fluid fittings connect inflation line 44 to outer hub 36 to deliver inflation fluid to superior balloon 34 via an inflation lumen within outer catheter shaft 32. Similarly, inflation line 46 connects to inner hub 42 to deliver inflation fluid to inferior balloon 40 via an inflation lumen within inner catheter shaft 38. In some embodiments, conventional occlusion balloons may be used as the controllable occlusion members or elements and may be compliant or non-compliant. Compliant balloons may be preferred in many clinical situations because of greater ease in adapting the occlusion to different size vascular lumens. Materials for compliant occlusion balloons include polyurethane or silicone, and in some cases polyether block amide (Pebax) materials for semi-compliant occlusion balloons. Non-compliant occlusion balloons would typically comprise materials such as polyethylene terephthalate (PET) or nylon.

[0039] Inflation fluid under pressure is provided and controlled by inflation unit 48, which includes controllable pump 50 for superior balloon 34, and controllable pump 52 for inferior balloon 40. Controllable pumps 50 and 52 may comprise, for example, stepper motor driven syringe pumps. Other pump types may be adapted by persons of ordinary skill based on the teachings of the present disclosure. Inflation unit 48 also includes processor control 54, which communicates with pumps 50 and 52 via communication link 56, which may be a hardwired or wireless communication channel. Processor control 54 may be disposed within a housing of inflation unit 48, or with wireless communication links. Processor control 54 may be located apart from pumps 50 and 52. For example, in the case of an implanted device such as system 30, processor control 54 may reside outside the patient’s body while the pumps are implantable units. Processor control 54 may include one or more processors, memory devices, input / output interfaces, and one or more non-transitory computer-readable media storing instructions that, when executed by the processor(s), cause the system to perform control, monitoring and sensing operations described herein.

[0040] At least four pressure sensors are provided with system 30. For example, superior vena cava pressure sensor 60 and right atrial pressure sensor 62 are provided above and below superior vena cava balloon 34. Similarly, suprarenal IVC pressure sensor 64 and infrarenal IVC pressure sensor 66 are provided above and below inferior vena cava balloon 40. Communication links 68link to processor control 54 to provide pressure measurement signals as inputs to control algorithms executed by processor control 54. In some embodiments pressure sensors 60, 62, 64, 66 may be provided as electronic pressure sensors, in which case communication links 68 may be provided as wires embedded within the catheter walls, or as wireless communication links. Alternatively the pressure sensors may be provided as pressure sensing ports, which communicate with pressure sensing lumens leading to pressure transducers at the proximal end of the system.

[0041] With systems disclosed herein, whether introduced via the jugular vein as shown in FIG. 1 or via the femoral artery as shown in FIG. 2, the SVC occlusion member will reside in the SVC and IVC occlusion member will reside in the IVC, preferably below the renal veins. It may be preferable to position the SVC occlusion member just below the confluence of the left and right brachiocephalic veins or adjacent to the cavoatrial junction outside of the right atrium. The inner catheter shaft is slidable within outer catheter shaft in order to accommodate patients of different sizes and permit precise placement of the occlusion members.

[0042] An alternative catheter system 70, configured as a jugular vein access system, is illustrated in FIGS. 4-9. Persons of ordinary skill will appreciate that system 70 may also be configured for femoral artery access according to the teachings of the present invention. In the jugular vein access system as shown in FIGS. 4-9, catheter system 70 includes inner catheter shaft 72 and outer catheter shaft 74. In this embodiment, each of catheter shafts 72 and 74 are quadlumen catheter shafts as illustrated in the cross sections of FIGS. 6-8. Compliant proximal balloon 76 on outer catheter shaft 74 forms the superior occlusion element. Compliant distal balloon 78 on inner catheter shaft 72 forms the inferior occlusion element. Inflation fitting 80, such as a Y-arm with a luer lock connector, communicates with inferior balloon inflation lumen 94 (FIG. 7), and inflation fitting 82, such as a Y-arm with a luer lock connector at 45°, communicates with superior balloon inflation lumen 100 (FIG. 8).

[0043] In catheter system 70, pressure sensing is provided by pressure ports communicating with pressure sensing lumens in the inner and outer catheter shaft bodies. Outer catheter shaft pressure ports 84 and 86 (FIG. 5) each individually communicate with one of outer catheter pressure sensing lumens 102 (FIG. 8). Inner catheter pressure ports 88 and 90 (FIG. 5) each individually communicate with pressure sensing lumens 96 (FIG. 7). As shown in the cross sections of FIGS. 6-8, inner catheter shaft 72 also includes a central guidewire lumen 92 and outer catheter shaft 74 includes central lumen 98 to slidingly receive inner catheter shaft 72. In an alternative embodiment, instead of pressure ports 84, 86, 88 and 90, pressure sensing may beprovided by MEMS pressure sensors at locations 84, 86, 88 and 90, which communicate with a controller via wires embedded in catheter shaft walls or positioned within one or more of the lengthwise lumens.

[0044] Further alternative embodiments of balloon occlusion elements are illustrated in FIGS. 10-16. For example, FIGS. 10 and 11 illustrate multi-lobe occlusion balloons 110, 112 and 114. As shown therein, inflation of separate balloon lobes 116 create a flow space (FS) between the balloons and vessel wall (V). Balloon lobes 116 are disposed on catheter body 118. Other examples of alternative occlusive elements include spiral balloons 120 and 122 shown in FIGS. 12 and 13. As shown therein, the spiral balloon elements form a reduced area flow path 124 at their center. Spiral balloons are mounted on catheter 126 with catheter tip 128.

[0045] In another example, FIGS. 14-16 illustrate expandible and collapsible braided wire or laser cut tube occlusion elements that move between collapsed as-delivered and expanded / occlusive states by rotation in response to column load. Alternatively, expansion and collapse can be accomplished in reverse where the expanded shape is shape set in place and the collapsed state occurs when the feature is lengthened or a sheath is drawn over it. FIG. 14 shows collapsed occlusive element 134 such as in the as-delivered state. FIG. 15 shows occlusive element 136 in an intermittently fully expanded state to provide partial occlusion as explained above. FIG. 16 illustrates occlusive element 138 expanded to a size smaller than the diameter of the vessel wall (V) in order to provide an annular flow space (FS) around the body of the occlusive element. Occlusive element 138 is disposed on catheter 140, which may include expansion control means and pressure sensing as described above. Occlusive elements 134, 136 and 138 may be constructed from biocompatible alloys such as stainless steel orNitinol and also may optionally be provided with coverings to increase impermeability, such as PET or polytetrafluoroethylene (PTFE) films.

[0046] Using systems and devices as disclosed herein, persons of ordinary skill may derive and employ a number of different treatment algorithms based on various relevant clinical parameters. For example, through a triage approach to algorithm development, key physiological parameters can be identified that are critical inputs to a therapy algorithm while others can be noted as subservient physiological parameters that should be optimized within the bounds of critical safety physiological parameters.

[0047] It is well-understood that in a decompensated heart failure patient there are at least two critical parameters: 1) a high cardiac preload resulting from, and leading to, hypervolemia andreduced cardiac efficiencies and 2) a high renal afterload resulting from, and leading to, a high central venous pressure and a low renal gradient that prevents adequate urine output and continues the cycle of hypervolemia and high cardiac preload. As discussed above in the Background, while there are therapies that individually address each of the above critical parameters, those parameters are related or interdependent. Embodiments disclosed herein synergistically address these interdependent parameters in an integrated system and methodology while also addressing potential safety concerns that may arise in a therapy which targets the optimization of both parameters simultaneously.

[0048] While not wishing to be bound by any particular theory, the following explanation of a control methodology and inter-relationship of clinical parameters is provided to aid in understanding certain aspects of the present disclosure. For example, Cardiac Preload reduction can be considered a critical physiological parameter driving the control disclosed systems, i.e., a ‘driving physiological parameter’. In some embodiments, Cardiac Preload is controlled (at least initially) at a level deemed safe through SVC occlusion alone. In a decompensated heart failure patient, the level of this driving physiological parameter is noted as a ‘max cardiac preload reduction’ . This driving physiologic parameter has a corresponding Right Atrial Pressure that defines a critical ‘safety physiological parameter’. A Right Atrial Pressure that corresponds to the max cardiac preload reduction becomes a safety physiological parameter that bounds the optimization of any ‘subservient physiological parameter’. Renal afterload is identified as a subservient physiological parameter that is being targeted to be reduced through IVC occlusion. Thus, using systems and methods disclosed herein, control of IVC occlusion can be implemented through a means that is bounded by the safety physiological parameter while optimizing the subservient physiological parameter.

[0049] An additional safety physiological parameter that may be applied is the duration of the ‘ SVC Occlusion Relief Time’ . It may be preferred that this parameter be maximized to prevent or reduce potential for neurological deficit, but it is also recognized that Cardiac Preload reduction is not maintained during periods of SVC Occlusion relief. Through the integration of IVC occlusion, reduced Cardiac Preload can be maintained during periods of SVC Occlusion Relief. However, to mitigate concerns of a reduction in Cardiac Output and / or systemic BP, systemic BP may be noted as a ‘safety physiological parameter’ to be maintained above a threshold. This threshold can be either a derived parameter or a clinician inputted parameter. An alert of this threshold parametercould either result in a decrease in IVC occlusion time, or a reduction in the % occlusion (or IVC balloon volume) that is being held.

[0050] Through the control of ‘SVC Occlusion Time’, ‘SVC Occlusion Relief Time’, ‘IVC Occlusion Time’, and ‘IVC Balloon Volume’ the driving physiologic parameter of Cardiac Preload can be controlled while also optimizing subservient physiologic parameters or Renal Afterload. Applying control techniques and systems as taught herein, this can be done within limits of safety physiologic parameters of Right Atrial Pressure, Cardiac Output, and Systemic Blood Pressure.

[0051] One illustrative example of a treatment algorithm established in accordance with the above principles and employing systems disclosed herein is illustrated in FIGS. 17A-C. It will be noted by persons of ordinary skill that the algorithms illustrated in FIGS. 17A-C are exemplified by reference to a system using balloons as the occlusion members. As will be appreciated, the teachings and methodology disclosed are equally appliable to non-balloon or mechanical occlusion members as elsewhere described herein.

[0052] FIG. 17A shows a baseline target setting module 202 in which the treatment begins with a cardiac load modulation system as described above introduced into the patent’s vasculature with occlusion balloons positioned in the SVC and IVC (204). A typical placement positions the distal end of the SVC occlusion balloon at the right atrium (RA) and the proximal end of the IVC balloon at the renal veins, although the physician may choose other placements based on the clinical presentation and individual patient factors. After placement, the occlusion balloons are temporarily sequentially inflated and the inflation volumes recorded while pressure gradient across each balloon is monitored (206). The SVC occlusion balloon volume corresponding to inflection in right atrial pressure (RAP) is noted. Also, the IVC occlusion balloon volume corresponding to inflection in infrarenal pressure is noted. The relationship between pressure gradients and occlusion balloon volumes may be used to tailor the relative amount (%) of occlusion. For mechanical occlusion members as in FIGS. 14-16, instead of inflation / occlusion volumes, the position of the mechanical actuator denoting an expansion diameter corresponding to occlusion is noted. In each case, a parameter indicating a repeatable full occlusion diameter for the occlusion member is determined, by fluid volume for balloons, or by mechanical actuator indication for occlusion members other than balloons.

[0053] Next, the SVC occlusion balloon is inflated to SVC Occlusion Volume for a period of 5 minutes while the RAP is measured (208) to establish a target RAP. An initial 5 minute SVCocclusion time may be selected based on past clinical experience establishing the safety of occlusion for this time period. Also determined is a Maximum Preload Reduction corresponding to the decrease in Initial RAP to Target RAP. A Maximum Upper Drainage Pressure may be established as the proximal SVC pressure after 5 minutes of SVC occlusion. The Maximum Upper Drainage Pressure sets a maximum safe upper pressure limit the brain can tolerate safely. An initial SVC occlusion relief period of 30 seconds follows the 5 minutes SVC occlusion period. The 5 minutes on - 30 seconds off SVC occlusion cycle may be repeated or adjusted as further described below.

[0054] During the 30 second SVC occlusion relief period, with the SVC occlusion balloon deflated, the IVC balloon is inflated initially in 5% increments from 70 to 100% of IVC occlusion volume for periods of 30 seconds while RAP and Renal Afterload are measured (210). The IVC occlusion volume at which the previously established target RAP is achieved is set as the IVC Partial Occlusion Volume (max). The Supra Renal Pressure at IVC Partial Occlusion Volume is set as the Target Renal Afterload. It should be noted that using the ‘target RAP’ level from SVC occlusion will provide an IVC occlusion percentage that should be able to be safely held. Persons of ordinary skill will note one of the synergistic advantages of the dual therapy systems and methods disclosed in that preload reduction can be maintained during period of SVC / cerebral relief, unlike when SVC occlusion is used alone.

[0055] After initial target setting 202, physician tuning module 212 is executed as shown in FIG. 17B. Initially, physician inputs are gathered and effected to tailor treatment (214). This step allows physicians to tailor therapy based on specific goals and safety profiles for individual patients, for example, more IVC occlusion time and diuresis for a heavily hypervolemic patient, more SVC occlusion relief time for patients that are sensitive neurologically. If not altered by the physician, initial default SVC occlusion is set as 2.5 min SVC Occlusion Time followed by 2.5 min of SVC Relief Time. It will be noted that an increase in the ‘SVC Relief Time’ may place more emphasis on control of the RAP from IVC Occlusion, which may be preferable or desirable in some clinical situations. A Target Renal Afterload Adjustment may be set with a default set as no adjustment. It will be noted that an increased Afterload Adjustment will focus the therapy more on Diuresis while reducing the amount of cardiac preload reduction. At 216, alert ranges are identified before therapy begins. Alert ranges are typically set initially as ranges off of values established at baseline 202, at which a sustained time above the range will alert the physician. Default alert ranges may include:RAP: + / - 3mmHg, Systemic BP: + / - 10 mmHg, Infra Renal IVC: + 5 mmHg, and Supra Renal IVC: + 5 mmHg. Additional safety parameters also may be utilized to check for possible system malfunction, e.g. balloon migration, or leakage as may be devised by persons skilled in the art based on the present teachings.

[0056] In another alternative embodiment, level of diuresis may be used as a control parameter for IVC balloon occlusion to achieve a specified pressure gradient (e.g., 5 mm Hg) between the infrarenal and suprarenal pressure sensors. Such an embodiment may be implemented as a closed loop system where balloon inflation volume is controlled directly by the control unit based on realtime or near real-time feedback of the (suprarenal - infrarenal) pressure. A similar closed loop control method may be used to target a specific desired pressure gradient across the SVC balloon occlusion balloon as well. In a further variation, the pressure gradient measured across one occlusion balloon may be used as a control input for the inflation level of the other occlusion balloon. For example, a pressure gradient measured across the proximal and distal pressure sensors at the SVC occlusion balloon may be used as a control parameter for inflation level of the IVC occlusion balloon and vice versa. In such embodiments, an advantage of the present disclosure is realized in that changes to the SVC balloon result (and could be controlled by) in changes in measured response at the IVC (for instance Infrarenal IVC pressure) or where changes in the IVC balloon result in or are controlled by changes in a measured response at the SVC (for instance RA Pressure).

[0057] After all settings are confirmed, a selected therapy based on the prior determinations is executed by therapy module 218, for example, as in FIG. 17C. Therapy module 218 typically includes repeating SVC occlusion times 220 and SVC relief times 222, repeating and alternating with IVC relief times 224 and IVC occlusion time 226. In one example, the SVC occlusion cycles between full occlusion for the determined SVC occlusion time and no occlusion for the determined SVC relief time, while the IVC occlusion cycles between no to low partial occlusion for the determined IVC relief time and high partial occlusion for the IVC occlusion time. In some embodiments, low partial occlusion may correspond to about an occlusion of about 10% to 60%, and in another example may be in a range of about 20% to 50%. High partial occlusion in some embodiments may correspond to an occlusion of about 70% to about 90%. In one illustrative example, the low partial occlusion of the IVC may be at about 50% and the high partial occlusion at about 80% occlusion. In some clinical situations, depending on patient parameters, it may be desirable to slightly overlap one occlusion time with the opposite relief time as shown in FIG. 17C.However, it is contemplated that more typically the SVC occlusion time will be aligned with the IVC relief time and the IVC occlusion time aligned with the SVC relief time in a sequential manner.

[0058] The number of cycles performed in therapy module 218 can be set by the physician. After therapy module 218 is completed, a physician review and adjustment module 228 may be executed. In module 228 system parameters are reviewed and new set points for use in physician tuning module 212 can be determined. For example, review may include review of control chart for key physiological parameters, review of alerts and review of set points and alert ranges. In a further alternative embodiment, a machine learning based module is included to adjust the control algorithm based on new, learned information on key patient parameters. Such parameters may include inherent parameters like IVC / SVC pressures, balloon volumes, etc., but could also include inputted parameters like urine output, systemic blood pressure, cardiac output, etc.

[0059] Baseline target setting module 202, physician tuning module 212, therapy module 218 and physician review and adjustment module 228, may be configured as software modules, which, as used herein refers to a set of computer-executable instructions stored on a non-transitory computer-readable medium and configured to perform one or more specific functions or operations when executed by one or more processors, which in turn operate and control the vascular occluders and occlude actuators as taught herein. A software module may comprise, for example, source code, object code, scripts, libraries, routines, or other organized blocks of program logic that execute algorithms as set out hereinabove for setting system targets, tuning system parameters, therapy control and post-therapy parameter adjustment. Software modules as disclosed herein thus have a defined structure and organization in code, and may be implemented using known programming techniques and arranged in a manner that is executable by computing hardware. Each software module may interact with other modules or system components via defined interfaces or APIs. Based on the teachings of the present disclosure including the specific algorithms described, a person of ordinary skill may configure a system in accordance with the present disclosure in order to provide improved patient therapies for treatment of ADHF.

[0060] Additional alternative embodiments include a cardiac load modulation system, comprising an outer catheter body having a proximal end configured to reside outside patient and a distal end configured to be received in a patient’s vasculature, an inner catheter body slidably received within the other catheter body with a proximal end extending proximally with respect to the outer catheter body proximal end and a distal end extending distally with respect to the outercatheter body distal end, an occlusion balloon disposed at the distal end of the inner catheter body, and an occlusion balloon disposed at the distal end of the outer catheter body.

[0061] In other embodiments, cardiac load modulation systems may further comprise inflation pumps communicating with each of the occlusion balloons through the respective catheter bodies. Pressure sensors may be disposed on the catheter bodies distally and proximally with respect to each occlusion balloon. Embodiments may also comprise a processing system controlling the inflation pumps and receiving pressure inputs from the pressure sensors. The processing system may be configured to execute a control algorithm comprising repeating, alternating, sequenced occlusion and relief times for the occlusion balloons. In some embodiments, one occlusion balloon is configured for placement in and occlusion of a patient’s IVC and the other occlusion balloon is configured for placement in and occlusion of the patient’s SVC.

[0062] The foregoing has been a detailed description of illustrative embodiments of the disclosure. It is noted that in the present specification and claims appended hereto, conjunctive language such as is used in the phrases “at least one of X, Y and Z” and “one or more of X, Y, and Z,” unless specifically stated or indicated otherwise, shall be taken to mean that each item in the conjunctive list can be present in any number exclusive of every other item in the list or in any number in combination with any or all other item(s) in the conjunctive list, each of which may also be present in any number. Applying this general rule, the conjunctive phrases in the foregoing examples in which the conjunctive list consists of X, Y, and Z shall each encompass: one or more of X; one or more of Y; one or more of Z; one or more of X and one or more of Y; one or more of Y and one or more of Z; one or more of X and one or more of Z; and one or more of X, one or more of Y and one or more of Z.

[0063] Various modifications and additions can be made without departing from the spirit and scope of this disclosure. Features of each of the various embodiments described above may be combined with features of other described embodiments as appropriate in order to provide a multiplicity of feature combinations in associated new embodiments. Furthermore, while the foregoing describes a number of separate embodiments, what has been described herein is merely illustrative of the application of the principles of the present disclosure. Additionally, although particular methods herein may be illustrated and / or described as being performed in a specific order, the ordering is highly variable within ordinary skill to achieve aspects of the present disclosure. Accordingly, this description is meant to be taken only by way of example, and not to otherwise limit the scope of this disclosure.

Claims

What is claimed is:

1. A cardiac load modulation system, comprising: an outer catheter body having a proximal end configured to reside outside patient and a distal end configured to be received in a patient’s vasculature; an inner catheter body slidably received within the other catheter body with a proximal end extending proximally with respect to the outer catheter body proximal end and a distal end extending distally with respect to the outer catheter body distal end; a first controllable vascular occlusion member disposed at the distal end of the inner catheter body; a second controllable vascular occlusion member disposed at the distal end of the outer catheter body; and first and second occlusion actuators configured to control a time and degree of vascular occlusion for the first and second controllable vascular occlusion members.

2. The cardiac load modulation system of claim 1, further comprising pressure sensors disposed on said catheter bodies distally and proximally with respect to each said controllable occlusion member.

3. The cardiac load modulation system of claim 2, further comprising a processing system controlling said first and second occlusion actuators and receiving pressure inputs from said pressure sensors.

4. The cardiac load modulation system of claim 3, wherein said processing system executes a control algorithm comprising repeating, alternating, sequenced occlusion and relief times for said occlusion balloons.

5. The cardiac load modulation system of claims 1, 2, 3 or 4, wherein the first and second controllable vascular occlusion members comprise occlusion balloons.

6. The cardiac load modulation system of claim 5, wherein the first and second occlusion actuators each comprise an inflation pump communicating with each said occlusion balloon through the respective catheter bodies.

7. The cardiac load modulation system of claim 6, wherein at least one said occlusion balloon comprises a compliant balloon.

8. The cardiac load modulation system of claim 6, wherein at least one said occlusion balloon comprises a multi-lobe occlusion balloon defining reduced flow path between lobes of the balloon when inflated.

9. The cardiac load modulation system of claim 6, wherein at least one said occlusion balloon comprises a spiral occlusion balloon defining a reduced flow path through a center of the spiral balloon when inflated.

10. The cardiac load modulation system of claims 1, 2, 3 or 4, wherein at least one of the first and second controllable occlusion members comprises a mechanically expandable metal mesh structure with a covering to prevent blood flow when expanded.

11. The cardiac load modulation system of claim 10, wherein the occlusion actuator controlling the mechanical expandable metal mesh structure comprises two relatively moveable control members at an outer hub of the catheter system.

12. The cardiac load modulation system of any of claims 1, 2, 3 or 4, wherein one said controllable occlusion member is configured for placement in and occlusion of a patient’s inferior vena cava (IVC) and one said controllable occlusion member is configured for placement in and occlusion of the patient’s superior vena cava (SVC).

13. A method of cardiac load modulation, comprising: intermittently occluding a patient’s superior vena cava (SVC) alternating between an SVC occlusion time and an SVC relief time with reduced SVC occlusion; intermittently occluding the patient’s inferior vena cava (IVC) alternating between an IVC occlusion time and an IVC relief time with reduced IVC occlusion; and controlling said intermittent occluding of the SVC and IVC sequentially such that the SVC occlusion time at least substantially aligns with the IVC relief time and the IVC occlusion time at least substantially aligns with the SVC relief time.

14. The method of claim 13, wherein said controlling comprises occlusion times to partially overlap with relief times.

15. The method of claim 13, wherein said intermittently occluding the SVC and IVC comprises controlling expansion and contraction of occlusion members disposed in the SVC and the IVC.

16. The method of claim 15, further comprising delivering a catheter system into the patient’s vasculature, said catheter system including an SVC occlusion member and an IVC occlusion member.

17. The method of claim 16, further comprising: positioning the SVC occlusion member in the SVC and positioning the IVC occlusion member in the IVC inferior of the renal arteries; and adjusting a length of the catheter system between the SVC and IVC occlusion members in accordance with the positioning of said occlusion members.

18. The method of claim 17, wherein said positioning of the SVC occlusion member in the SVC comprises placement of the SVC occlusion member below the confluence of the left and right brachiocephalic veins.

19. The method of any of claims 15, 16, 17 or 18, further comprising, prior to said intermittently occluding the SVC and the IVC, determining a full occlusion diameter for the SVC occlusion member and a full occlusion diameter for the IVC occlusion member.

20. The method of claim 19, wherein: said determining the full occlusion diameter for the SVC occlusion member comprises identifying an inflection in right atrial pressure (RAP) while increasing the diameter of the SVC occlusion member and correlating the diameter of the SVC occlusion member at said RAP inflection with the full occlusion diameter of the SVC occlusion member; and said determining the full occlusion diameter for the IVC occlusion member comprises identifying an inflection in infrarenal pressure while increasing the diameter of the IVC occlusion member and correlating the diameter of the IVC occlusion member at said infrarenal pressure inflection with the full occlusion diameter of the IVC occlusion member.

21. The method of claim 19, further comprising determining a partial occlusion diameter for the IVC occlusion member.

22. The method of claim 21, wherein said determining the partial occlusion diameter for the IVC occlusion member comprises: determining a target RAP by fully occluding the SVC for a predetermined time period and designating measured RAP at the end of the predetermined time period as the target RAP; andincreasing IVC occlusion with no SVC occlusion while measuring RAP and setting the partial occlusion diameter for the IVC as the diameter of the IVC occlusion member at the target RAP.

23. The method of claim 22, further comprising: controlling the SVC occlusion member to be at the full occlusion diameter for the SVC occlusion time; controlling the IVC occlusion member to be at a low partial occlusion diameter for the IVC relief time substantially corresponding to the SVC occlusion time; controlling the IVC occlusion member to be at a high partial occlusion diameter for the IVC occlusion time; and controlling the SVC occlusion member to be fully contracted for the SVC relief time substantially corresponding to the IVC occlusion time.

24. The method of claim 23, wherein said occlusion members comprise occlusion balloons and said occlusion diameters are measured as balloon inflation volumes.

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