Destination therapy Mechanical support as destination therapy James

Destination therapy Mechanical support as destination therapy James Young MD Head, Heart Failure and Cardiac Transplant Medicine Cleveland Clinic Foundation Cleveland, OH Mehmet Oz MD Director, Cardiac Assist Device Program Columbia Presbyterian Medical Center New York City, NY Geetha Bhat MD Ph. D Director, Heart Failure and Cardiac Transplant Center Jewish Hospital Louisville, KY Heartbeat – November 2001

Destination therapy Overview of the field Axial flow pumps are an example of the trend away from old pusher-plate technology • Micromed (De. Bakey pump) • Jarvik 2000 (Jarvik Inc) • Heart. Mate II (Thoratec) Heartbeat – November 2001

Destination therapy Challenges of axial flow pumps It is more difficult to monitor how much blood is flowing through the pump No traditional blood pressure No pulse you can measure traditionally Heartbeat – November 2001

Destination therapy Jarvik 2000 solution Jarvik 2000 VAD ©Texas Heart Institute “We don’t care about pumping all the blood, we’ll pump less than all the blood in order to make sure we don’t suck the heart down into the device. ” Oz Heartbeat – November 2001

Destination therapy Centrifugal flow pumps Many groups moving to centrifugal flow pumps • Heart. Mate III (Thoratec) • AB 180 i. VAD (Cardiac. Assist) • Cor. Aide (Arrow International) • Biomedicus Biopump (Medtronic) “These pumps are in theory more efficient than axial flow pumps. ” Oz Heartbeat – November 2001

Destination therapy Forgettable pumps Major stumbling blocks to “forgettable” systems • miniaturization – especially power supply • infection control “Patients get them, and they don’t realize they have them anymore, nor do the people around them. ” Oz Heartbeat – November 2001

Destination therapy Patients for the artificial heart As we have gained more experience we realize that death in the operating room isn’t the real definition of right heart failure • who is unable to come off of inotropic support? • who has irreversible end organ injury? • who is unable to return to normal exercise capacity? Heartbeat – November 2001

Destination therapy Need for total artificial heart Over time, there are progressive changes in the native heart. “From a medical need perspective, we will ideally want maybe ¼ of the patients to be supported with total artificial heart support. ” Oz Heartbeat – November 2001

Destination therapy Sizing issues Patients must be sized very meticulously to be able to use an artificial heart. Need enough room and need to not kink off key structures Abiomed came up with a special algorithm to determine if a patient is acceptable – Abio. Fit™ Heartbeat – November 2001

Destination therapy Abio. Cor Heartbeat – November 2001

Destination therapy Cardiologist assessment Patients for the Abio. Cor need to be assessed by a cardiologist in advance of implantation • must be non-transplantable • must be scanned and measured for sizing • limited to large men (no small men or women) Heartbeat – November 2001

Destination therapy Use of the artificial heart LVADs do an excellent job as bridge to transplant, but there would still be a role for artificial hearts in: • patients who deteriorate rapidly after placement of LVAD • patients not suitable for transplant Bhat Heartbeat – November 2001

Destination therapy State of the patients Robert Tools, world's first recipient of the Abio. Cor Implantable Replacement Heart. First two patients are doing as well as can be expected Source: Jewish Hospital “Since he’s the first patient we’re still working on how to do the discharge planning for the future. ” Bhat Heartbeat – November 2001

Destination therapy Totally implantable From an internal medicine perspective, total implantability is a huge step • portable • no external connections • transcutaneous power minimizes the consoles and excess baggage of the old systems Heartbeat – November 2001

Destination therapy Patient selection If they are too ill for transplant, are they too ill for mechanical therapy? • there are more sick patients than hearts to transplant • it may be better not to use a rare transplanted heart on weaker patients • if we can save more people with devices, the costs involved must be discussed Oz Heartbeat – November 2001

Destination therapy Which path to take Moving to more complicated full support is better, or do we move to smaller, less complicated support? • equally large populations • both approaches are needed “The way I envision this being a decade from now is […] not to bother with the coronaries and just plug in a support device that gives them 2 or 3 liters extra blood flow every minute. ” Oz Heartbeat – November 2001

Destination therapy Later transplantation If a patient improves sufficiently on the artificial heart, could they be considered for a transplant? • the Abio. Cor trials insisted on nontransplant candidates • if the patients improve sufficiently, the trial allows for them to be considered for transplant Heartbeat – November 2001

Destination therapy Patients who improve Some patients improve drastically • score system created with Cleveland Clinic for stratifying patients • the younger patients are the ones most likely to tolerate the insult and recover • of more concern is the group that stays in the ICU with end-organ dysfunction Heartbeat – November 2001

Destination therapy Three outcomes These patients are divided into three outcomes after device implantation • they survive and do well • they die on the operating table or soon after • they linger on in the ICU - the worst outcome Heartbeat – November 2001

Destination therapy The challenge “In the early days of piggyback assist device use […] our biggest challenges were convincing patients that this was not human experimentation. That they would get the quality and dignity of life they desired, and not just be an experiment. ” Oz Heartbeat – November 2001

Destination therapy Patient advocate The Abio. Cor trial protocol includes a patient advocate to look out for the patient’s needs “As these people look normal, the American public will make peace with the fact that you can have a bionic heart, and it is something that Granddad can have. ” Oz Heartbeat – November 2001

Destination therapy End-stage organ failure Selection criteria has always been a problem • patients with irreversible end-organ damage are not a good subset • experience with the LVADs have shown us patients can do fairly well Bhat Heartbeat – November 2001

Destination therapy Major concern The worry is that they go to the operating room with borderline function, but they develop less recoverable function “If we envision these patients like planes taking off from an aircraft carrier, they dip a little bit before they actually get airborne. And if we’re too close to the water when we launch them, they hit that water. ” Oz Heartbeat – November 2001

Destination therapy REMATCH Randomized Evaluation of Mechanical Assistance Therapy for Congestive Heart Failure • it will answer some questions but raise many others • we cannot rule out devices as a solution for heart failure • who should get devices, and who should not? Oz Heartbeat – November 2001

Destination therapy Cost benefit We need an open dialogue on the costbenefit of these systems “[This is a dialogue] we can either have behind closed doors, by important agencies not addressing the problem, or we can have it a more public level, which is going to be painful, but is probably worth having. ” Oz Heartbeat – November 2001

Destination therapy Bridge to recovery? We have not yet succeeded in providing long-term survival in bridge to recovery • about 10 out of >225 have had devices removed • most have not survived long term, and are back in the hospital with heart failure • the more we learn about why they recover even partially, the closer we will be Heartbeat – November 2001

Destination therapy Explantable patients? It’s an intriguing field, with lots of basic science questions • what happens at the cellular level? • what happens when a device is placed? • what kinds of markers might predict an explantable patient? Cor. Cap™ cardiac support device Courtesy Acorn Cardiovascular, Inc Heartbeat – November 2001

Destination therapy Source: Jewish Hospital Heartbeat – November 2001