Systems and methods for left ventricular unloading in biologic therapy or vectored gene therapy

Abstract

To provide methods and systems for using mechanical circulatory support concurrently with a biologic therapy (e.g., a gene therapy vector).SOLUTION: Particular adaptation includes a cardiac therapy method comprising: occluding a blood vessel such as a coronary artery; injecting a gene therapy vector or biologic to a site distal to the occlusion site; and waiting for a certain amount of time; while using the mechanical circulatory support system to provide circulatory support to a patient.SELECTED DRAWING: None

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 826,444, filed March 29, 2019, and No. 62 / 959,333, filed January 10, 2020, both of which are incorporated herein by reference. [Background technology]

[0002] background Cardiovascular disease is the leading cause of morbidity, mortality, and healthcare burden worldwide. Various treatment modalities for cardiovascular disease have been developed, ranging from medicines to medical devices and ultimately transplantation. Temporary cardiac assist devices, such as ventricular assist devices, provide hemodynamic support and promote cardiac recovery. There are also ventricular assist devices, such as the IMPELLA® family of devices (Abiomed, Inc., Dunbar, Massachusetts), that are inserted percutaneously into the heart and can supplement cardiac output in tandem with the natural heart.

[0003] Cells or organs such as the heart can be treated by genetic engineering to introduce genes into targets. See, for example, Julie A. Wolfram, PhD et al., Gene Therapy to Treat Cardiovascular Disease, JAHA Vol 2, Issue 4 (2013) ("Wolfram"), the entirety of which is incorporated herein by reference. Methods of gene therapy include the use of one or more gene therapy vectors, whether viral or non-viral. In the case of viral vectors, the genome of a virus can be programmed and then injected into a patient as a gene therapy vector with the hope that the viral genome will be expressed in the patient. At least one example of a viral vector is the adeno-associated virus (AAV). The vector can be administered by injection or perfusion in various locations. For example, the vector genome can be delivered to the entire myocardium by coronary vascular perfusion. Generally, high expression of the gene is required to achieve a therapeutic effect. At least one disadvantage of administering viral vectors to the coronary vessels is that the heart rapidly delivers the vector genome into the systemic circulation, making the technique relatively inefficient. The heart's extrusion may result in the vector genome being cleared too quickly from the heart to achieve the desired gene expression. The virus passes through the heart relatively quickly, leaving a relatively short time to attach to and fully transduce the myocardium. The same problem occurs when administering biological therapy to the heart. The technique of arresting the heart to slow the clearance rate of the vector genome or biological agent and allow for prolonged retention in the heart leads to cardiac instability and / or ischemia.

[0004] It would therefore be desirable to have a system and method that can reduce the rate of clearance of vector genomes and biologics in the heart without the downsides associated with stopping or slowing the heart. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Julie A. Wolfram, PhD et al., Gene Therapy to Treat Cardiovascular Disease, JAHA Vol 2, Issue 4 (2013) Summary of the Invention

[0006] overview The methods, systems, and devices described herein allow efficient delivery of biological therapy, such as, but not limited to, gene therapy vectors, to the myocardium by (i) temporarily blocking blood flow to the myocardium to increase myocardial absorption of the biological therapy (e.g., gene therapy vector) and reduce clearance of the biological therapy (e.g., gene therapy vector) from the heart, while simultaneously injecting the biological therapy (e.g., vector gene therapy) to operate a mechanical circulatory assist device in the heart to maintain cardiac function and systemic circulation without adverse effects to the patient. At least one benefit of these methods, systems, and devices is the ability to increase the attachment of the biological therapy (e.g., gene therapy vector) in the myocardium. By temporarily stopping blood flow by deploying an angioplasty balloon in at least one coronary vessel (i.e., the arteries and blood vessels surrounding and supplying the heart) and injecting a biological therapy, such as a gene therapy vector virus, distal to the deployed balloon, the viral medium pools in the coronary artery, allowing the therapy, such as a viral vector, a significant amount of time for transduction of the myocardium. By injecting the biological therapy while activating the mechanical circulatory support device, the patient can maintain vital cardiac output and survive ischemic events that may result from an inflated angioplasty balloon, essentially acting as a temporary cardiac bypass. The mechanical support device can be a blood pump, such as an Impella device. In some embodiments, the biological therapy, such as a gene therapy vector, can be targeted to specific cardiac tissues, such as fibroblasts or endothelial cells. In some embodiments, one or more gene therapy vectors can be used to preferentially target myocytes, fibroblasts, endothelial cells, or other target tissues.

[0007] In a first exemplary embodiment, a method of treating a heart includes activating a mechanical circulatory assist device to assist the heart. In some embodiments, the mechanical circulatory assist device is operated outside the patient's body, while in other embodiments, the mechanical circulatory assist device is inserted into the patient. The method further includes activating the mechanical circulatory assist device for an assistance period, and administering a biological therapy, such as a gene therapy vector, to the heart during the assistance period. In one example, the gene therapy vector is administered into a blood vessel of the heart. In another example, the method further includes inserting an angioplasty balloon into the blood vessel and inflating the balloon to temporarily close the blood vessel. In one example, the gene therapy vector is administered to the heart at a location distal to the angioplasty balloon. For example, the gene therapy vector is administered downstream of the inflated balloon in a coronary artery. In some examples, the gene therapy vector may be administered over the course of several periods. For example, a first dose of the gene therapy vector is administered to the heart during a first administration period, followed by a second dose of the gene therapy vector to the heart during a second administration period, both administration periods separated by a rest period. In one example, the rest period is longer than the first administration period. In one example, the inflated angioplasty balloon temporarily occludes the blood vessel for less than about 3 minutes, preferably 1 minute. In one example, the assistance period in which a mechanical circulatory assist device, such as a microaxial transvalvular pump, is used is longer than 10 minutes. The assist device is activated during these various administration and rest periods. In one example, administration of the gene therapy vector to the heart is configured to increase expression of the vector DNA in cardiac tissue. The gene therapy vector can be targeted to tissues within the heart, such as myocardium, fibroblasts, endothelial cells, or other cardiac tissue.

[0008] In a second exemplary embodiment, a method of assisting a patient's heart includes percutaneously inserting a blood pump into the heart and positioning the blood pump across the aortic valve of the heart. The method further includes activating the blood pump to unload the left ventricle of the heart, and injecting a gene therapy vector into a coronary vessel of the heart that has been blocked as described herein simultaneously with activating the blood pump.

[0009] In a third exemplary embodiment, a method of upregulating gene expression in a patient's myocardium includes placing a balloon in a patient's coronary artery and inflating the balloon for a first period of time to temporarily block blood flow in the coronary artery for the first period of time. The method further includes placing a blood pump in the patient's heart and positioning the pump across the aortic valve of the heart, and then operating the blood pump in the patient's heart for a second period of time. The method includes injecting a gene therapy vector into the coronary artery at a location distal to the inflated balloon during the first period of time, and deflating the balloon after the first period of time to restore blood flow in the coronary artery. In this exemplary embodiment, the first period of time is within the second period of time, and the first period of time has a duration that does not cause permanent ischemia to cells of the myocardium. In one example, the method includes injecting a biological therapy, such as a gene therapy vector, into the coronary artery at a location distal to the inflated balloon during the second period of time. In another example, the method includes injecting the gene therapy vector into the coronary artery at a location distal to the inflated balloon for a third time period less than or equal to the second time period. The duration of the first time period can be less than 3 minutes, preferably less than 1 minute.

[0010] In a fourth exemplary embodiment, a method of assisting a patient's heart includes administering a biological therapy, such as a gene therapy vector, into the heart. The method further includes reducing the clearance rate of the biological therapy, such as a gene therapy vector, from the heart. In an embodiment in which the biological therapy is a gene therapy vector, the reduced clearance rate results in expression of the gene therapy vector in the heart, transduction of the heart by the gene therapy vector, or any combination thereof. In one example, the method deploys a mechanical circulatory assist device and a balloon catheter in the heart.

[0011] In a fifth exemplary embodiment, a cardioprotection system for assisting the heart of a patient experiencing cardiogenic shock or myocardial infarction deploys a mechanical circulatory assist device configured to be inserted into the patient and operative, and a balloon catheter having an inflatable balloon having a proximal end and a distal end. The balloon catheter includes an inflation catheter in fluid communication with the proximal end of the balloon, the balloon configured to be inserted into a coronary artery of the patient for simultaneous use with the mechanical circulatory assist device. The system further deploys a delivery catheter for delivering gene vector therapy in vivo, the delivery catheter having a proximal end with an inlet opening configured to receive a solution containing a gene therapy vector, a distal end with an outlet opening, and a tube extending between the proximal and distal ends of the delivery catheter. The balloon is configured to at least partially occlude blood flow through the coronary artery when inflated. In one example, the mechanical circulatory assist device is a catheter-based intravascular blood pump. In another example, the outlet opening is configured to be located distal to the distal end of the balloon when the balloon is inflated. In yet another example, the tube extending between the proximal and distal ends of the delivery catheter has a longer longitudinal length than the balloon. In another example, the balloon catheter is configured such that the balloon does not obstruct the exit opening of the balloon catheter upon inflation of the balloon. In aspects in which a gene therapy vector is administered, the vector can include a non-naturally occurring nucleic acid material encoding a peptide that has a cardioprotective function when expressed in vivo, and the gene therapy vector is configured to be taken up by cardiomyocytes.

[0012] In a sixth exemplary embodiment, a method of treating the heart includes activating a mechanical circulatory assist device to assist the heart. The method further includes activating the mechanical circulatory assist device for an assistance period, occluding at least one cardiac vessel, and administering a biological therapy to the occluded cardiac vessel. The biological therapy may preferentially target myocytes, fibroblasts, endothelial cells, or other target tissue. [Brief description of the drawings]

[0013] The above and other objects and advantages will become apparent from the following detailed description considered in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout.

[0014] [Figure 1] Illustrates gene expression levels in various cardiac tissues from three groups of pigs receiving biologic therapy using viral gene therapy vectors: (i) without Impella support (pigs IGT5, IGT6, IGT12), (ii) with Impella support and without angioplasty balloon (pigs IGT7, IGT8, IGT10), and (iii) with Impella support in combination with angioplasty balloon (pigs IGT4, IGT9, IGT11). [Diagram 2] Gene expression levels in left atrial tissue from three groups of pigs are illustrated in Figure 1. Pigs received biologic therapy using viral gene therapy vectors (i) without Impella support (pigs IGT5, IGT6, IGT12), (ii) with Impella support and without angioplasty balloon (pigs IGT7, IGT8, IGT10), and (iii) with Impella support in combination with angioplasty balloon (pigs IGT4, IGT9, IGT11). [Diagram 3] Gene expression levels in liver tissue from three groups of pigs are illustrated in Figure 1. Pigs received biologic therapy using viral gene therapy vectors (i) without Impella support (pigs IGT5, IGT6, IGT12), (ii) with Impella support and without angioplasty balloon (pigs IGT7, IGT8, IGT10), and (iii) with Impella support combined with angioplasty balloon (pigs IGT4, IGT9, IGT11). [Figure 4] Vector genome expression is illustrated in one pig (pig IGT11) receiving biologic therapy using a viral gene therapy vector with Impella support and angioplasty balloon, as measured by PCR of vector genome and pig genome. [Diagram 5]Illustrates vector genome expression in one pig (pig IGT11) undergoing biologic therapy using a viral gene therapy vector with Impella assistance and angioplasty balloon, assuming a constant DNA weight per pig cell. [Figure 6] Illustrates the correlation between luciferase activity and vector genome expression in various tissue samples from one pig (Pig IGT11) that underwent biologic therapy using a viral gene therapy vector with Impella assistance and angioplasty balloon. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Detailed Description To provide an overall understanding of the systems and methods described herein, certain exemplary embodiments are described. Although the embodiments and features described herein are specifically described for use in connection with circulation and reperfusion therapy systems, it will be understood that any of the components and other features outlined below may be combined with one another in any suitable manner and may be adapted or applied to other types of circulation and reperfusion therapy devices.

[0016] As mentioned above, in one embodiment, gene therapy vectors are introduced into the closed vessels of a mechanically assisted heart. Figures 1-6 illustrate results from a gene therapy vector study conducted in pigs. For the first pig control group, pigs were numbered in this study as pig 5 was called IGT5, pig 6 was called IGT6, and so on. Three groups of pigs were considered. In the first pig control group ("Group 1"), adeno-associated viral vector type 6 (AAV6) and luciferase (an enzyme that produces bioluminescence) were injected into the coronary vessels, and neither an angioplasty balloon nor a mechanical circulatory system device was used. In the second pig group ("Group 2"), the left ventricle was unloaded with a mechanical circulatory system device (Impella pump) while the gene therapy vector was injected into the coronary vessels. Angioplasty balloons were not used. In a third group of pigs ("Group 3"), an angioplasty balloon was placed in the coronary vessel and the coronary vessel was injected distal to the balloon with the gene therapy vector, and a mechanical circulatory system device (Impella pump) was used simultaneously with the injection. As part of the study protocol, the gene therapy vector injections were performed in phases, with a first injection phase followed by a period of no injection, a second injection phase followed by a period of no injection, and finally a third injection phase followed by a period of no injection.

[0017] Figure 1 illustrates the results observed for three groups of pigs during the porcine study. The Y-axis is a measurement of the level of luciferase in the tissue biopsies, which correlates with several genes expressed in the muscle cells. The assay lights up when luciferase is expressed, and the intensity of the light correlates with the amount of vector genome expressed in the tissue. The Y-axis uses a logarithmic scale, with a value of 1 indicating normal genome expression. The various data points (posterior, post endo, post epi, apex, infarct, margin) correspond to different regions of the myocardium where the biopsies were taken. As shown in Figure 1, compared to groups 1 (no Impella) and 2 (with Impella and no balloon), pigs in group 3 (with balloon and Impella) show a logarithmically higher level of vector genome expression than groups 1 or 2. At least one advantage of using angioplasty balloons and mechanical circulatory assist devices simultaneously is the ability to prolong the time that gene therapy vector vehicles pool within the myocardium while maintaining cardiac stability. The duration of angioplasty balloon deployment is relatively short, e.g., less than one minute, and although some degree of myocardial stunning (brief tissue ischemia) may result from occlusion of the coronary vessels, the effects of myocardial stunning are reversible.

[0018] Figure 2, similar in format to Figure 1, illustrates the expression levels of the vector genome for left atrial tissue biopsies. As shown in Figure 2, one pig from group 3, pig 11 (IGT11), had a 3000-fold increase in luciferase activity, indicating extremely high levels of gene expression.

[0019] Figure 3 is similar in format to Figure 1, but illustrates the expression levels of vector genomes for liver tissue biopsies. When using biological therapies employing viral vectors, it is desirable to minimize the presence of virus outside of the target organ. Preferably, the level of virus in the patient's systemic circulation should be low. Organs such as the liver, which are intended to clear the systemic circulation, indicate how much virus was cleared from the system before reaching the liver. As shown in Figure 3, the expression level in the liver is lower than the expression expectation value 1 in the third group of pigs. This indicates that the majority of the vector virus was output near the injection site, i.e., into the myocardium, and that only a small amount of vector virus reached the liver, which is desirable.

[0020] Figure 4 illustrates the expression levels of the vector genome in pig 11 from the same porcine study, but in a different format than in Figures 1-3. Figure 4 shows the results of the biologic therapy employing the gene therapy vector using a PCR test, i.e. polymerase chain reaction test. The results of the treatment employing the gene therapy vector for pig 11 (one from group 3: using Impella and angioplasty balloon) are consistent with the results shown in Figures 1-3 by PCR, with pig 11 (and pigs from group 3) showing higher expression levels of the vector gene in certain cardiac tissues than in the rest of the system. In the graph on the left, the y-axis is the gene expression measured by PCR, and the x-axis corresponds to the different biopsies from different tissue areas. The levels of PCR are much higher in tissue areas corresponding to the heart (apex, infarct, margin, posterior epithelium, posterior endothelium, mid-septum, base-anterior, base-lateral, base-posterior, base-septum, coronary vessels, and left atrium) than in other tissue areas (RV, RA, liver, SKM, lung, renal cortex, spleen, brain, CM, non-CM). This confirms that the majority of the gene therapy vector is expressed in cardiac tissues, with very little expression in other organs. Similarly, in the graph on the right, the proportion of vector genome in porcine 11 (IGT11) normalized by the porcine genome is significantly higher in coronary vessels and left atrium tissue biopsies than in any other tissue biopsy (brain, CM, kidney, liver, lung, non-CM, RV, SKI, spleen).

[0021] Figure 5 displays another measure of gene therapy vector expression in the pig study. The therapy vector genome is normalized by the amount of DNA in a single pig cell, assuming 6 pg of DNA in a single pig cell. Again, the ratio of therapy vector genome to pig genome was highest in tissue biopsies of the left atrium and coronary vessels, indicating that this is where the gene therapy vector is most efficient.

[0022] FIG. 6 illustrates the correlation between a gene therapy vector indicator (luciferase) of the type discussed in FIGS. 1-3 and a gene therapy vector indicator (PCR) of the type discussed in FIGS. 4-5. FIG. 6 plots luciferase activity on the y-axis and the ratio of vector genome / pig genome on the x-axis. FIG. 6 confirms that luciferase activity is directly related to viral genome (VG) expression. The higher the ratio of vector genome to pig genome, the higher the luciferase (Luc) activity.

[0023] The same techniques described above for gene therapy vectors can be used to increase the uptake of other biologics such as stem cells, RNA, mRNA, antisense oligonucleotide therapy, polypeptides, or any other biologic that is taken up by the heart. For example, the methods can be used with oligonucleotides that disrupt gene production in the heart, or any other molecules with similar functions. In another example, biologics such as proprotein convertase subtilisin kexin type 9 (PCSK9), tumor necrosis factor (TNF) inhibitors, or RNA interference biologics targeted to manage or inhibit inflammatory responses in cardiac tissue can be injected into the heart. Treatment of cardiac diseases and conditions can be improved by intracoronary injection of various biologics into the myocardium or any other target tissue type, such as fibroblasts or endothelial cells. Biologic therapies may be preferentially targeted to myocytes, fibroblasts, endothelial cells, or other target tissues.

[0024] The biologic therapy is administered intravascularly in the heart, and may be administered in combination with the use of an angioplasty balloon in the blood vessel to temporarily occlude the blood vessel. The biologic therapy may be administered at a location distal to the angioplasty balloon in the heart, for example, at a location distal to the angioplasty balloon in a coronary artery. In some instances, the biologic therapy is administered over the course of several periods separated by rest periods during which the biologic therapy is not administered. The rest periods may be longer than the periods during which the biologic therapy is administered.

[0025] Depending on cardiac symptoms, biologics can be injected into the heart in combination with each other or in combination with gene vector therapy.To deliver any biologic to myocardium or any other target tissue type, such as fibroblasts or endothelial cells, blood flow in blood vessels is temporarily blocked to increase the absorption of biologic in cardiac tissue and reduce the clearance of biologic from the heart, while mechanical circulatory support device is simultaneously operated in the heart to maintain cardiac function and systemic circulation without adverse effects to the patient.By blocking blood flow during administration of biologic, the biologic can be in contact with cardiac tissue for transduction into desired tissue target for a longer time.

[0026] In this specification, the word "comprising" is to be understood in the broad sense, i.e., in the sense of "including", and therefore not limited to the narrow sense, i.e., "consisting only of". Where the corresponding words "comprise", "comprised" and "comprises" appear, they have corresponding meanings.

[0027] Although specific aspects of the technology have been described, it will be apparent to those skilled in the art that the technology may be embodied in other specific forms without departing from its essential characteristics. Accordingly, the aspects and examples herein should be considered in all respects as illustrative and non-limiting. For example, although the present disclosure describes detection of movements such as gestures and rotations based on hands / arms, the same principles can be applied to other large-scale movements, such as when a user moves from lying down on a bed to sitting up (or vice versa), or when reaching for a specific target (such as a table lamp or a breathing device).

[0028] It will be further understood that reference herein to subject matter known in the art does not imply an admission that such subject matter is well known to those skilled in the art, unless a contrary statement is made.

Claims

1. activating the mechanical circulatory assist device for a period of assistance; occluding the blood vessel during said assistance period; and administering a biological therapy to the heart during said assistance period.

23. A method of treating the heart comprising:

2. 10. The method of claim 1, wherein the mechanical circulatory assist device operates at one of the following rates: a blood flow of at least 2.5 L / min, a blood flow of at least 3.5 L / min, or a blood flow of at least 5 L / min.

3. 3. The method of claim 1 or claim 2, wherein the biological therapy is administered into an obstructed blood vessel.

4. inserting an angioplasty balloon into a blood vessel; and inflating the angioplasty balloon to temporarily occlude the blood vessel.

4. The method of claim 3, further comprising:

5. administering the biological therapy to the heart, delivering said biological therapy to a location distal to the angioplasty balloon within the patient's blood vessel; 5. The method of claim 4, comprising:

6. 6. The method of claim 5, wherein the patient's blood vessel is a coronary artery and the biological therapy is administered downstream of an inflated angioplasty balloon within the coronary artery.

7. administering the biological therapy to the heart; administering a first dose of a biological therapy to said heart during a first administration period; providing a first pause period; and administering a second dose of the biological therapy to said heart during a second administration period.

7. The method of claim 4, 5, or 6, comprising:

8. 8. The method of claim 7, wherein administering the biologic therapy comprises injecting the biologic therapy intravascularly.

9. 5. The method of claim 4, wherein the inflated angioplasty balloon occludes the blood vessel for less than about 3 minutes.

10. 5. The method of claim 4, wherein the inflated angioplasty balloon occludes the blood vessel for less than about 1 minute.

11. 2. The method of claim 1, wherein the support period is one of: greater than 10 minutes, greater than 15 minutes, greater than 20 minutes, or greater than 30 minutes.

12. 2. The method of any one of the preceding claims, wherein the duration of the biological therapy is one of less than 10 seconds, less than 30 seconds, less than 1 minute, less than 3 minutes, or less than 5 minutes.

13. 8. The method of claim 7, wherein the first resting period is longer than the first administering period.

14. 8. The method of claim 7, wherein the first administration period is longer than the second administration period.

15. 8. The method of claim 7, wherein the mechanical circulatory assist device is activated during a first application period, a first rest period, and a second application period.

16. The method of claim 1 , wherein the mechanical circulatory assist device comprises a blood pump.

17. 17. The method of claim 16, wherein the blood pump is a microaxial blood pump.

18. 10. The method of claim 1, wherein administering the biological therapy comprises injecting the biological therapy into one of a coronary blood vessel, myocardium, fibroblasts, or endothelial cells.

19. 10. The method of claim 1, wherein the mechanical circulatory assist device operates at one of the following rates: a blood flow of at least 2.5 L / min, a blood flow of at least 3.5 L / min, or a blood flow of at least 5 L / min.

20. The method of any one of the preceding claims, wherein the biological therapy is a gene therapy vector.

21. 21. The method of claim 20, wherein administering the gene therapy vector to the heart is configured to increase expression of vector DNA in cardiac tissue.

22. percutaneously inserting a blood pump into a patient and positioning the blood pump across an aortic valve of the patient's heart; operating the blood pump to unload the left ventricle of the patient's heart; occluding a blood vessel in the patient's heart; and injecting a biological therapy into the patient's coronary vessel simultaneously with operating the blood pump and occluding the vessel.

4. A method of providing cardiac assistance to a patient, comprising:

23. The blood vessel, placing a balloon in a coronary artery of the patient; and inflating the balloon for a first period of time to block blood flow in the coronary artery for a first period of time. The method of claim 22, wherein the closure is performed by

24. 24. The method of claim 22 or 23, wherein the biological therapy is a gene therapy vector.

25. placing a balloon within a coronary artery of a patient; inflating the balloon for a first period of time to temporarily block blood flow in the coronary artery for a first period of time; placing a blood pump within the patient's heart and disposing the blood pump across an aortic valve of the heart; operating the blood pump within the patient's heart for a second period of time; and injecting a gene therapy vector into said coronary artery at a location distal to the inflated balloon during a first period of time; and deflating the balloon after a first period of time to restore blood flow within said coronary artery.

1. A method for upregulating gene expression in the myocardium of a patient, comprising: the first period is within the second period, and the first period has a duration that does not result in permanent ischemia to cells of the patient's myocardium; method.

26. 26. The method of claim 25, further comprising injecting the gene therapy vector into the coronary artery at a location distal to the inflated balloon during a second period of time.

27. and injecting the gene therapy vector into the coronary artery at a location distal to the inflated balloon during a third period of time; The third period is less than or equal to the second period; 27. The method of claim 26.

28. 26. The method of claim 25, wherein the first period of time is less than 3 minutes in duration.

29. 30. The method of claim 28, wherein the first period of time is less than 1 minute in duration.

30. 30. The method of claim 29, wherein the first period of time is less than 30 seconds in duration.

31. Mechanical circulatory assist devices; a balloon catheter having an inflatable balloon having a proximal end and a distal end, and a dilatation catheter, the dilatation catheter being in fluid communication with a proximal end of the balloon of the balloon catheter, the balloon being configured to be inserted into a coronary artery of a patient for simultaneous use with the mechanical circulatory assist device; A delivery catheter for delivering a biological therapy in vivo, the delivery catheter having a proximal end with an inlet opening configured to receive a solution containing the biological therapy, a distal end with an outlet opening, and a tube extending between the proximal and distal ends of the delivery catheter. A cardiac protection system comprising: The balloon is configured to at least partially occlude blood flow through the coronary artery when inflated. Cardioprotective system.

32. 32. The cardioprotection system of claim 31 , wherein the mechanical circulatory assist device is a catheter-based intravascular blood pump.

33. 32. The cardiac protection system of claim 31, wherein the exit opening at the distal end of the delivery catheter is configured to be located distal to the distal end of the inflatable balloon catheter when the balloon of the balloon catheter is inflated.

34. 32. The cardiac protection system of claim 31, wherein a tube extending between the proximal and distal ends of the delivery catheter has a longer longitudinal length than the balloon.

35. 32. The cardioprotection system of claim 31, wherein the balloon catheter is configured such that the balloon does not block the exit opening of the delivery catheter upon balloon inflation.

36. The cardioprotection system of any one of claims 31 to 35, wherein the biological therapy is a gene therapy vector.

37. The cardioprotective system of claim 36, wherein the gene therapy vector comprises a non-natural nucleic acid substance encoding a peptide having cardioprotective function when expressed in vivo, and the gene therapy vector is configured to be absorbed into cardiomyocytes.

38. activating a mechanical circulatory assist device while occluding the blood vessel; During the occlusion, a gene therapy vector is administered into the patient's heart and the steps of: (i) reducing the rate of clearance of the gene therapy vector from the patient's heart; (ii) effecting expression of the gene therapy vector in the patient's heart; and (iii) effecting transduction of the patient's heart with the gene therapy vector. and 4. A method of providing cardiac assistance to a patient, comprising:

39. 40. The method of claim 38, wherein a balloon catheter is used to close the blood vessel.

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