CORONARY OSTIAL CARDIAC CIRCULATION ISOLATION CATHETER AND VENTRICULAR UNLOADING REPERFUSION SYSTEMS AND METHODS

Abstract

An interventional ostium occlusion catheter includes a catheter tube with at least one port at a first end, a tip at a second end, and a central lumen, with a positioning component and an occlusion component on the surface of the catheter tube close to the tip. A method of coronary intervention using the catheter includes maneuvering the catheter to an ostium; inserting the catheter into a coronary vessel; activating the positioning component and the occlusion component; and delivering an infusion via the lumen. An interventional system for improving management of ischemic cardiac tissue during acute coronary syndromes includes the catheter; a blood infusion device that delivers controlled reperfusate; and a ventricular unloading device that manipulates myocardial oxygen demand in a coronary chamber. The operator can mitigate reperfusion-related and oxygen-related tissue injury by precisely modulating oxygen re-exposure when re-establishing flow and when using a ventricular unloading device.

Claims

1. An interventional ostium occlusion catheter comprising: a catheter tube having at least one port at a first end, a tip at a second end opposite the first end, and a central lumen; a positioning means joined to a surface of the catheter tube distal from the port; and an occlusion means joined to the surface of the catheter tube distal from the at least one port.

2. The interventional ostium occlusion catheter of claim 1, wherein the at least one port is selected from the group consisting of: a perfusion flow port, a therapy catheter port, a positioning balloon port, an occluding balloon port, and any combination thereof.

3. The interventional ostium occlusion catheter of claim 1, wherein the positioning means is a positioning balloon configured to be smaller than an inner diameter of an access vessel and larger than an inner diameter of its ostium.

4. The interventional ostium occlusion catheter of claim 1, wherein the positioning means is nitinol wire needles configured to engage an ostium atraumatically.

5. The interventional ostium occlusion catheter of claim 1, wherein an occluding balloon is the positioning means and the occlusion means.

6. The interventional ostium occlusion catheter of claim 1, wherein the occlusion means is an occluding balloon.

7. A method of coronary intervention, comprising: providing an interventional ostium occlusion catheter having a lumen, a positioning component, and an occlusion component; maneuvering the interventional ostium occlusion catheter to a first coronary ostium; activating the positioning component; activating the occlusion component; and delivering an infusion via the lumen.

8. The method of claim 7, further comprising inserting an interventional device through the lumen.

9. The method of claim 7, further comprising providing an external blood pumping mechanism operative to pump the infusion.

10. The method of claim 7, further comprising providing a ventricular unloading device operative to reduce oxygen demand in a coronary tissue.

11. The method of claim 7, wherein the infusion is delivered through the lumen prior to activating the positioning component.

12. The method of claim 7, wherein the first coronary ostium is a right ostium.

13. The method of claim 7, wherein the first coronary ostium is a left ostium.

14. The method of claim 7, further comprising inserting the interventional ostium occlusion catheter into a first coronary ostium before or after activating the positioning component.

15. The method of claim 7, wherein the first coronary ostium is a coronary sinus ostium, and the infusion is controlled perfusate blood; and further comprising initiating retrograde flow of the infusion via the lumen.

16. The method of claim 15, further comprising initiating antegrade flow control.

17. The method of claim 7, further comprising: providing a second interventional ostium occlusion catheter having a lumen, a positioning component, and an occlusion component; maneuvering the second interventional ostium occlusion catheter to a second coronary ostium opposite the first coronary ostium; and activating a second occlusion component of the second interventional ostium occlusion catheter.

18. The method of claim 7, further comprising providing and initiating operation of a ventricular unloading device and delivering the infusion down the lumen of the interventional ostium occlusion catheter at a flowrate operative to maintain antegrade blood flow and nutrient delivery to the heart.

19. The method of claim 18, wherein operation of the ventricular unloading device is initiated before delivering the infusion.

20. The method of claim 18, further comprising opening an infarct artery.

21. The method of claim 7, further comprising: controlling a blood parameter selected from the group consisting of: composition, oxygen content, flowrate, pressure, temperature, and any combination thereof.

22. The method of claim 21, further comprising measuring the parameter at a tip of the interventional ostium occlusion catheter.

23. The method of coronary intervention of claim 21, further comprising measuring the parameter utilizing a channel in the interventional ostium occlusion catheter.

24. An interventional system for improving management of ischemic cardiac tissue during acute coronary syndromes, comprising: an occlusion catheter; a blood infusion device; and a ventricular unloading device operative to manipulate myocardial oxygen demand in a coronary chamber, wherein the blood infusion device is operative to deliver controlled reperfusate.

25. The interventional system of claim 24, further comprising an interventional therapy catheter within the occlusion catheter, operative to perform coronary intervention during take over of a coronary circulatory system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 is a perspective schematic view of an aorta, illustrating the position of main arteries and their ostia;

[0042] FIG. 2 is a schematic view of an occluding catheter according to an embodiment of the present invention;

[0043] FIG. 3 is another schematic view thereof, illustrating use with a reperfusate pump;

[0044] FIG. 4 is a detail schematic view thereof, shown in use;

[0045] FIG. 5 is a detail schematic view of an occluding catheter according to another embodiment of the present invention, shown in use;

[0046] FIG. 6 is a detail cross-sectional view of the occluding catheter of FIG. 2, illustrating channels within the catheter leading to each balloon;

[0047] FIG. 7 is another detail cross-sectional view thereof, illustrating a guidewire passing through the lumen;

[0048] FIG. 8 is another detail schematic view thereof, illustrating passage of a therapy catheter through the lumen of the occluding catheter;

[0049] FIG. 9 is a schematic view of a heart, illustrating use of two of the occluding catheters of FIG. 2 in combination with a percutaneous ventricular assist device; and

[0050] FIG. 10 is a schematic view of a method of perfusate treatment, illustrating passage of the catheter from the inferior vena cava to a coronary bed of a heart.

DETAILED DESCRIPTION OF THE INVENTION

[0051] The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.

[0052] Broadly, one embodiment of the present invention is an interventional ostium occlusion catheter comprising a catheter tube with a central lumen, a surface, a positioning means, and an occlusion or occluding means.

[0053] Unlike other coronary guide catheters that take pains to avoid complete occlusion of a coronary artery vessel (e.g., by including side holes to maintain some level of perfusion), this catheter specifically and purposefully fully occludes the target vessel and provides a means to take over perfusion of that vessel and the entire subtended tissue and capillary bed. This represents a deviation from what is currently practiced or understood to be safe by those skilled in the art. It also represents what is explained herein to be a convergence of the practices of interventional cardiology and cardiac surgical protection in an innovative and non-obvious way.

[0054] The positioning means is a positioning component operative to control how deep into the main artery the occluding means goes to avoid accidentally occluding a branch. In some embodiments, the positioning means is a positioning balloon configured to be larger than the ostium to be occluded and smaller than the inner diameter of the artery through which it is routed. In other embodiments, other means of maintaining positioning, such as tiny nitinol wire needles deployed to engage the ostium atraumatically or other mechanical means attached to the outer surface of the catheter, may be used.

[0055] In one embodiment, the catheter does not have a separate positioning means. Rather, the interventionalist carefully positions the catheter before inflating the occluding balloon, which serves both occlusion and positioning functions.

[0056] The occlusion means may be an occlusion component such as an occluding balloon. The occluding balloon must operate more gently than (for example) angioplasty balloons. Thus, the structure and material of the balloon, as well as the balloon inflation system, is such that careful control is possible to ensure only “soft” and “gentle” pressure against the arterial wall that completely occludes the vessel at the ostium.

[0057] A significant issue with conventional (i.e., currently commercially available) catheters is that when therapy catheters are deployed into areas that cause them resistance (e.g., a vessel occlusion), the force required to push the therapy catheter forward can cause a backwards force in the guide catheter which can dislodge it from where it was placed. Considerable effort has gone into addressing this need for backup support. The present invention mitigates this problem because the occluding balloon can provide considerable anchoring forces to counteract this effect.

[0058] The ostium occluding guide catheter may be introduced into the patient via an access vessel using conventional techniques, such as via femoral or upper extremity puncture. Given that the size of this catheter may be on the larger end of the range, it is most readily introduced through a femoral access route, although other points of introduction may also be used. It is envisioned in another embodiment that a shorter and larger or possibly “variable diameter” catheter may be used (since resistance to flow increases with decreasing radius and increasing length) and deployable via a surgical cutdown to the axillary-subclavian system (much nearer to the heart). The catheter may be guided over a wire to the root of the aorta using conventional fluoroscopy methods. It is maneuvered using conventional techniques.

[0059] Catheters comprising features of the Ostium Occlusion Catheter (especially to create a “gentle” balloon occlusion) to enable the foregoing features and benefits can include modifications of those depicted in U.S. Pat. No. 10,980,652, FIGS. 1A and 1B; U.S. Pat. No. 7,862,601, FIGS. 1-3; and U.S. Pat. No. 10,092,429, FIGS. 10A-10B, 15-16, 18, and 42. Each of the named patents above is hereby incorporated in its entirety by reference, particularly for such catheter disclosures.

[0060] A method of use according to an embodiment of the present invention may comprise inserting the catheter and maneuvering the catheter into proximity to a coronary ostium. The positioning balloon is inflated to ensure that the catheter does not go too far into the coronary artery. The tip of the catheter may be allowed into the ostium before inflation to avoid having the aortic blood flow carry the catheter away. The catheter may be inserted into the ostium until the positioning balloon contacts the aortic wall and stops any further movement into the vessel. At that time, the occluding balloon may be inflated to fully occlude the vessel. The balloons are generally inflated using conventional techniques.

[0061] In some embodiments, the inventive method may provide deployment of two catheters [e.g., one for the right coronary artery (RCA) and one for the left main coronary artery (LM)] simultaneously. This allows the operator to control the entire coronary circulation in a manner similar to aortic clamping during cardiac surgery where the entire coronary circulation and the heart are isolated.

[0062] In cardiac applications, the catheter pair allows the coronary circulation to be isolated from the systemic circulation. This mimics the circulatory environment created in most open-heart surgery cases in terms of compartmentalization, but the heart is not arrested as with a “cardioplegia” solution. In this embodiment, the blood or solution delivered via the catheters can serve as a “vehicle” to deliver protection or adjuncts to protection either with or without simultaneous LV unloading and support. Each may also function as a guide catheter to support interventional procedures that include but are not limited to angioplasty and stent deployment.

[0063] Compartmentalization of flow and, potentially, segmentalized tissue condition determined with tissue condition sensors, is a critical component that can be used in conjunction with a number of other therapies, such as a percutaneous LV unloading device, coronary flow control, controlled oxygen exposure, and the addition of other molecules or ligands for protection that are known to be involved in protective signaling pathways. Thus, an interventional catheter (or catheters) allow(s) for the local circulation of the heart (or a different organ) to be taken over in part or in its entirety and controlled. These features and benefits have application not just to heart intervention therapies, but also the brain, other organs, and peripheral limbs. However, the heart must continue to work and supply sufficient blood and oxygen supply to the entire body during such procedures and while it is being intervened upon.

[0064] Although more comprehensive control of the cardiac circulatory system may be achieved utilizing a catheter per ostium, there are cases where deployment of a single catheter to control the circulation in one side of the heart can also provide significant therapeutic benefits. For example, a single ostium catheter may be used in a controlled reoxygenation procedure such as described in the Rheoxtech patents, discussed supra, during a coronary vessel angioplasty or other percutaneous intervention. The device herein disclosed, allowing blood flow through the lumen, may be advantageously used for such purposes.

[0065] In another embodiment, blood composition (including oxygen content) is controlled and varied over time during the procedure. Parameters including one or more of the blood composition, blood flowrate, pressure, temperature, pO.sub.2, etc. may be controlled by the operator utilizing a blood infusion device, i.e., an external blood pumping mechanism, such as a reperfusate pump, and by adding or removing blood components or compounds (e.g., amount of oxygen, drugs, ligands known to impact signaling in protection etc.). External control of blood composition and dynamics may continue until the balloons are deflated and the catheter is removed. In some embodiments, a measurement of the conditions at the distal end of the catheter may be made and communicated to the pumping mechanism (e.g., pressure, oxygen content, etc.). This may be done by sensors at a distal end of the catheter or in some cases (e.g., pressure) by a channel in the catheter that communicates with a sensor at a proximal end of the catheter. Other types of tissue-based sensors are also envisioned.

[0066] Interventional devices such as therapy catheters may also be passed through the internal lumen of the catheter to perform cardiac interventions such as angioplasty or stent deployments. Having control of the blood composition at the moment therapy is initiated or, more particularly, at the moment ischemic conditions are relieved, is critical to minimizing reperfusion injury.

[0067] In some embodiments, prior to inflation of the balloon or deployment of other positioning means, blood flow may be established through the catheter lumen to ensure that, once partial or full occlusion is established, adequate blood flow is being provided to the coronary vessels. Blood flow may be provided by a blood pump such as a heart lung machine, an ECMO circuit, or a roller pump. Blood flow through the lumen may be maintained so long as the catheter is engaged within the ostium and until either balloon is deflated and the catheter is removed from the ostium. Preferably, blood pumping/flow is performed by structures, and blood content for the infusion is determined and mixed, as disclosed in previously discussed prior art.

[0068] In some embodiments, the main right coronary artery is engaged and/or the right ostium is engaged.

[0069] In some embodiments, the main left coronary artery is engaged and/or the left ostium is engaged.

[0070] While the previous discussion is specific to ostium occlusion during an interventional procedure on the coronary arteries (e.g., angioplasty, stent placement, occlusion removal), the foregoing techniques have application as well during pVAD usage (with or without simultaneous interventional procedures). An interventional system and method are described for improving the management of ischemic cardiac tissue during acute coronary syndromes. The system combines a catheter-based sub-system which allows for infusion of a carefully controlled perfusate during percutaneous coronary intervention, with or without simultaneous balloon dilation of a coronary artery, along with manipulation of the myocardial oxygen demand (O.sub.2D) of the tissue by simultaneously implementing mechanical unloading of the chamber. In addition, systems and concepts are provided for modifying oxygen demand during an intervention that can be measured or monitored. This addresses the situation where the initiation of a pVAD that effectively unloads the heart at various flow rates, if ischemic conditions are relieved, paradoxically creates a moment of oxygen damage vulnerability for the previously ischemic tissue.

[0071] The system is described whereby as oxygen demand (O.sub.2D) is reduced through mechanical unloading of the heart to a level that is satisfactory for elimination or significant mitigation of ischemia in some areas of the heart (which may suffer diffuse but heterogeneous ischemia), the conditions of flow into an “infarct artery” may be simultaneously controlled in a manner that provides protection from over-exposure to oxygen.

[0072] In one embodiment of the invention, a method of preventing reoxygenation injury during acute PCI is provided comprising the initiation of pVAD support that effectively and impactfully reduces myocardial oxygen demand (O.sub.2D) and consumption (mVO.sub.2). As O.sub.2D drops, areas that become non-ischemic also become vulnerable to oxygen over-exposure. Control may be taken over the coronary circulation by occluding perfusion catheters and accompanied by immediate initiation of flow down the catheters to maintain antegrade blood flow and nutrient delivery. Although pVAD flow allows ongoing cardiac function, the workload of the heart may be reduced by as much as half and therefore careful control of the coronary circulation and blood composition is used to prevent reperfusion injury. The innovative therapy taught here is based at least in part on the discovery that the tissue is vulnerable to injury by merely lowering O.sub.2D. As O.sub.2D drops, the period of vulnerability to oxygen must be addressed in the moment ischemic conditions are eliminated, even though this occurs in a non-homogeneous manner.

[0073] In some embodiments, pVAD support is commenced prior to coronary blood flow being controlled. In other embodiments, coronary blood flow control is commenced prior to or during or at the same moment of initiation of pVAD support.

[0074] In some embodiments, the artery in the right coronary is engaged, and flow is started with controlled perfusate blood (such as Rheoxtech reperfusion disclosed in the Rheoxtech patents named above) into the artery in conjunction with the initiation of pVAD device flow, which is known to reduce O.sub.2D and to improve microvascular collateral flow to the infarct area. In fact, most collateral coronary flow is not well represented by angiographic assessment. For that very reason, tissue rendered no longer ischemic is protected by control of oxygen tension of the perfusate in the collateral vessel flow.

[0075] In some embodiments, an artery in the left coronary circulation is engaged, and flow is started with controlled perfusate blood (such as Rheoxtech reperfusion disclosed in the Rheoxtech patents named above) into the artery in conjunction with the initiation of percutaneous ventricular assist device (pVAD) flow. As pVAD flow is started, ischemia may be relieved in the area at risk without the need for the infarct artery to be opened immediately. As such, flow into the arteries that may be contributing to the collateral circulation to the infract zone may be controlled. In one embodiment, the left main coronary artery is engaged, and in another, the left ostium is engaged.

[0076] In another embodiment, in conjunction with pVAD support of the heart, both coronary circulatory systems are engaged by perfusion catheters with an occluding member to seal and isolate the coronary blood flow allowing for the control of antegrade flow composition into the infarct artery and/or the other arteries for the purpose of enhancing protection and the avoidance of too much oxygen delivery and too-high an oxygen gradient at the moment oxygen demand drops with initiation of left ventricle (LV) unloading. In one embodiment the left main artery is engaged and/or the right main is engaged. In another embodiment, the left ostium and/or right ostium is engaged.

[0077] In some embodiments, once pVAD support and control of a circulatory system is established, the infarct artery may be opened to controlled flow as well (such as Rheoxtech reperfusion disclosed in the Rheoxtech patents named above).

[0078] In another embodiment, the coronary sinus is engaged at the moment ventricular unloading therapy is initiated with a pVAD. The coronary sinus ostium is engaged with an occluding perfusion catheter, and retrograde flow is initiated with controlled perfusate blood (such as Rheoxtech reperfusion disclosed in the Rheoxtech patents named above) from a catheter in the coronary sinus. As pVAD flow is started, ischemia may be relieved in the area at risk without the need for the infarct artery to be opened immediately. As such, retrograde coronary sinus flow may flow into the area at risk prior to reestablishing flow into the “infarct artery”. It may also flow into arterial territory contributing to the collateral circulation to the area at risk or the infarct zone and, in so doing, reperfusion conditions may be controlled.

[0079] In another embodiment, retrograde flow control is combined with a form of antegrade flow control; including creating a siphon for gentle run-off of retrograde flow, and so as not to be perfusing both antegrade and retrograde at the same moment. Simultaneous retrograde and antegrade flow is known to be safe, however, for brief periods of time particularly for deairing purposes.

[0080] Referring to FIGS. 1 through 10, FIG. 1 illustrates a sinus portion of an aorta 18 with ostia 22, 26 that may be occluded by the inventive occlusion catheter. The Figure is discussed in more detail in the Background.

[0081] FIG. 2 depicts an ostium occlusion catheter 100 according to an embodiment of the present invention, having a perfusion flow port 106, a therapy catheter port 108, a positioning balloon port 110, and an occluding balloon port 116 at a first end of a lumen 102 and having a positioning balloon 114 and an occluding balloon 120 at a second end of the lumen 102. While the balloons 114, 120 are shown spaced apart on the lumen 102, the balloons 114, 120 may overlap, may be adjacent to one another, or may be positioned with a gap therebetween.

[0082] As shown in FIG. 3, an external blood pump 300, such as a reperfusate pump, fluidly communicating with the perfusion flow port 106 of the occlusion catheter 100 may be used in conjunction with the therapeutic techniques described above.

[0083] FIG. 4 illustrates an anchored catheter 100 engaged properly in the ostium 26 of the left main artery 24 from the sinus portion of the aorta 18. The blood composition, blood flow, pressure, temperature, pO.sub.2, etc. may be controlled by the operator utilizing an external blood pumping mechanism, such as the reperfusate pump 300 shown in FIG. 3. In some embodiments, a measurement of the conditions at the distal end 104 of the catheter 100 may be made and communicated to the pumping mechanism 300 (e.g., pressure, oxygen content, etc.). This may be done by sensors (not shown) at the distal end 104 of the catheter 100 or in some cases (e.g., pressure) by a channel (such as those shown in FIG. 6) or separate channel providing fluid communication between the proximal end and the distal end (not shown) in the catheter 100 that communicates with a sensor (not shown) at the proximal end 122 (see FIG. 3) of the catheter 100.

[0084] FIG. 5 depicts an alternative positioning means in the form of tiny nitinol wire needles 124 deployed to engage the ostium 26 atraumatically, so that the occluding balloon 120 may be inflated, occluding flow at a suitable location.

[0085] As seen in FIG. 6, the positioning balloon 114 fluidly communicates with the positioning balloon port 110 and is inflatable via a positioning balloon channel 112 and the occluding balloon 120 fluidly communicates with the occluding balloon port 116 and is inflatable via an occluding balloon channel 118. Both channels 112, 118 are isolated from each other and from other passages and lumens within the catheter 100.

[0086] A guidewire 62 may be inserted through the lumen 102, as seen in FIG. 7. The catheter may be guided over the guidewire 62 to the targeted ostium.

[0087] FIG. 8 illustrates passage of an interventional therapy catheter 60 through the lumen 102 of the occluding catheter 100 according to an embodiment of the present invention.

[0088] FIG. 9 depicts use of occluding perfusion catheters 100, 101 in conjunction with ventricular unloading therapy using a pVAD 200 according to an embodiment of the present invention. The pVAD 200 is inserted into the left ventricle chamber 30 through the aortic valve 28 by any suitable means. An inventive occluding catheter 100 enters the right main coronary artery 20 via the sinus portion of the aorta 18 and is positioned to occlude the right ostium 22. Another occluding catheter 101 enters the left main coronary artery 24 via the sinus portion of the aorta 18 and is positioned to occlude the left ostium 26 prior to the circumflex artery branch 46, the diagonal artery branch 48, and the left anterior descending artery 50. Arrows indicate the direction of flow, including within both catheters 100, 101 in the aorta 18 within the aortic wall 19. As pVAD 200 flow is started, ischemia may be relieved in the area at risk 32 within the ventricle muscle without the need for the infarct artery to be opened immediately. As such, retrograde coronary sinus 42 flow (see FIG. 10) may flow into the area at risk 32 prior to reestablishing flow into the “infarct artery”. It may also flow into arterial territory contributing to the collateral circulation to the area at risk 32 or the infarct zone and, in so doing, reperfusion conditions may be controlled.

[0089] FIG. 10 illustrates retrograde flow initiated with controlled perfusate blood from a catheter 100 in the coronary sinus 42 according to an embodiment of the present invention. As shown, the catheter 100 enters via the inferior vena cava 54 from the femoral arteries. However, deployment from the upper extremities (usually radial artery cannulation) via the superior vena cava 52 may alternatively be used, as illustrated in broken lines. The coronary sinus ostium 44 within the right atrium 58 is engaged with the occluding balloon 120 and positioned with the positioning balloon 114. Perfusate blood flow delivered to the coronary bed 56 is indicated by arrows. Note that the retrograde flow leaving the coronary bed 56 passes through the right and left ostia 22, 26 into the sinus portion of the aorta 18.

EXAMPLES

[0090] An example of a method of practicing the inventions includes:

[0091] 1) The pVAD and the occlusion catheters are advanced into position.

[0092] 2) pVAD flow is initiated and as flow of the pVAD increases, a source of venous blood is taken and pumped antegrade through the occlusion catheters.

[0093] 3) As O.sub.2D drops and flow in collaterals becomes adequate to perfuse previously ischemic tissue, such collateral flow is controlled (for example, with a venous to arterial blood composition and pO.sub.2 over a period of time).

[0094] 4) After pVAD flow is initiated and controlled oxygen level flow into all collaterals has commenced immediately; PCI is performed next with simultaneous initiation of controlled flow into the infarct vessel.

[0095] 5) After a period of time (for example, five to ten minutes of gradual reoxygenation), the catheters may be removed, and perfusion can be supplied via normal blood flow pathways.

[0096] 6) pVAD flow continues as needed (for example, anywhere from thirty minutes to three days) depending upon the overall recovery of function of the heart.

[0097] 7) If cardiac function is normal, pVAD flow may be weaned off after a period of time to ensure adequate percutaneous revascularization and controlled reperfusion and reoxygenation has been completed.

[0098] An example of a treatment process and flow to practice embodiments of the invention may include the following:

[0099] 1. A patient with evolving infarction is brought to the interventional area. [0100] a. The patient may have ST elevation MI (where it is assumed one artery or another is 100% occluded). [0101] b. The patient may also have non-ST elevation MI or even unstable angina (both acute coronary syndromes) that harbor diffuse but heterogeneous ischemia.

[0102] 2. In either case, the operator selects the artery to be opened first as dictated by the relevant clinical information.

[0103] 3. Arterial and venous sheath access is obtained for blood pump flow and a site (or sites) for introduction of the interventional (PCI) catheters is chosen (likely femoral but may be an alternative site).

[0104] 4. pVAD of whatever type is deployed.

[0105] 5. Priority is given to engaging the coronary ostia with the occluding catheters and deployment of the pVAD into the ventricle for unloading rather than reestablishing flow into the infarct vessel.

[0106] 6. pVAD is initiated with LV unloading commenced.

[0107] 7. (pVAD flow may be, but is not likely, begun unless and until access to the coronary ostia is obtained and engaged.) [0108] a. as LVAD flow is begun, wall tension drops and is governed by device flow rate. [0109] b. as device flow is brought up; myocardial oxygen demand drops to a level that may eliminate ischemic conditions surrounding the central aspect of an infarction (in the case of a ST-elevation myocardial infarction [STEMI]) or may improve conditions diffusely but heterogeneously. [0110] c. Paradoxically, this can create a moment of vulnerability of the ischemic but salvageable tissue to over exposure to oxygen. [0111] d. Scientific research has shown and validated that at the moment of exposure of vulnerable tissue to an oxygen gradient, oxidative injury occurs and may be irreversible depending on the severity of the pre-existent ischemia.

[0112] 8. In tissue sensors may be used to help inform and guide the process. [0113] a. optionally, sensor technology is deployed to guide the starting point of the therapy and, possibly, its duration

[0114] 9. Controlled reperfusate flow (venous pO2) is commenced immediately upon engaging the ostia and deployment of the occluding member of the catheter tip.

[0115] 10. Alternately, coronary flow with controlled perfusate may be commenced before pVAD is deployed and/or pVAD flow is commenced. [0116] a. As controlled flow into the coronary arteries is commenced and as pVAD flow is ramped up to unload the LV chamber, the myocardial oxygen demand drops by a variable amount that is dependent upon rate of flow of the device. [0117] b. As device flow increases, wall stress (known to be a critical ingredient in what governs oxygen demand) drops. [0118] c. Accordingly, mVO2 drops as well. [0119] d. Certain coronary locations are at risk as demand drops [0120] e. Ischemic conditions may in some cases be relieved merely by initiating device flow and, and in the border zone of the infarction, careful control of oxygen exposure is facilitated by the above-referenced techniques. [0121] f. Especially in areas that may be reperfused by collateral flow previously embarrassed by either loading conditions, overall presence of multi-vessel coronary artery lesions, patient condition (hypertension, tachycardia from anxiety, etc.) or merely unable to keep up with demand prior to unloading (simultaneously): as demand drops, flow may improve. [0122] g. The embarrassment and subsequent improvement in collateral flow is not necessary, however for the concept to be valid as micro-vascular flow is improved by decreases in wall tension in most cases. [0123] h. Merely dropping demand (O.sub.2D) may be enough to create this vulnerability to oxygen overload.

[0124] 11. In this embodiment, the pO.sub.2 of the controlled reperfusate catheter flow may be gradually ramped up over a period of (e.g., five to thirty) minutes (not hours) to effectively avoid any over-exposure.

[0125] 12. In some cases, a percutaneously deployable sensor that samples various areas of the myocardium during the described resuscitation may be utilized. [0126] a. TE echo may guide the deployment of the sensor into various areas with or without wall motion abnormalities to guide therapy.

[0127] It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.