A pioneer in the field of transcatheter aortic valve implantation (TAVI), Michael Reardon (professor of cardiovascular surgery, Academic Institute Methodist DeBakey Heart & Vascular Center, Houston, USA) is known for his involvement in major studies including the CoreValve, SurTAVI and Reprise III TAVR trials. He talks to Cardiovascular News about his career to date and the future of research into TAVI.
Why did you decide to become a doctor and why, in particular, did you decide to go into cardiothoracic surgery?
I started out my college career aiming to be a mechanical engineer as I have always been fascinated with how things work. Growing up, I did not know any physicians, or even how one became a physician. In college I was exposed to people on a pre-med pathway and decided that learning how people work would be more interesting than how machines work. I attended medical school at Baylor College of Medicine in 1975, at this point Michael DeBakey and Denton Cooley were both giants in the field of cardiovascular surgery. I knew I wanted to be a surgeon, so choosing cardiovascular surgery was almost a given.
Who have been your career mentors?
I had the opportunity to train for five years with Michael DeBakey and two years with Denton Cooley. I became chief of cardiothoracic surgery at Baylor College of Medicine after DeBakey retired and worked next door to Cooley. After training with both, I also got the opportunity to work with, and get to know them both personally at a faculty level. Both influenced me greatly. In my later career, I have watched carefully and tried to emulate Michael Mack, Marty Leon and Jeff Popma in the field of transcatheter treatment of structural heart disease and Alan Lumsden as a leader in endovascular therapy.
What has been the most important development in cardiothoracic surgery during your career?
There have been many great advances in my career—the use of the left internal mammary artery (LIMA) for coronary artery bypass (CAB), mitral valve repair, better methods of cardioplegia, percutaneous coronary intervention (PCI)—but by far the most impressive to me has been TAVI and what it offers my patients.
What has been the biggest disappointment? Something you hoped would change practice but did not?
I was convinced as a young man that we would have a functional, reliable, and easy to use total artificial heart by now. We are still waiting for this, but I am very excited with developments for potential minimally invasive support devices.
What are your current research interests?
I am deeply involved in three areas of research. This includes transcatheter therapies for structural heart disease, as well as aortic diseases—I am currently the national principal investigator for a stent graft trial for type A aortic dissection—and cardiac tumours, especially complex and malignant cardiac tumours. We have the largest experience in primary cardiac sarcoma in the world and have written extensively on this topic.
You were among the principal investigators in the landmark SURTAVI clinical trial—what do you believe have been the major insights gained from this trial?
I am the surgical principal investigator on SURTAVI (intermediate risk), Evolut low risk, Reprise III, Acurate and Portico NG. SURTAVI and Evolut Low risk together helped move TAVI into intermediate and then low-risk groups. The insights from these two randomised trials are that TAVI is extremely safe with lower early mortality than surgery with less atrial fibrillation, bleeding and stroke. Surgery still does better with pacemakers and paravalvular leakage (PVL) but both are rapidly improving for TAVI. Both trials, when taken with the results of Partner IIA and Partner 3, are amazing advances in a very short period.
What do you believe are the factors that should be taken into consideration when deciding between TAVI and surgery, as TAVI moves into the treatment of low-risk populations?
Age and potential length of life left are the main issues which are similar to the decisions surgeons face when moving from a mechanical to a biologic aortic valve replacement. A large unknown for TAVI is the longer-term durability of the valves. So far, TAVI valves seem to be tracking surgical biologic valve durability, but the TAVI populations have been older and it is still too early for definitive answers. As we get older, we have less life span left and surgical—and I will assume TAVI— biologic valves last longer. No one knows exactly why that is the case, although I think it may be a low-grade immune reaction—as we age, our immune system weakens and attacks these valves with less vigour. The issue for TAVI will be similar to that of surgeons looking between mechanical and tissue valves—where do you draw the age line? The low risk randomised trials have a mean age of four, and one standard deviation was six years, so this may provide guidance.
What are the key unanswered questions around TAVI that future research should prioritise?
Valve durability is a key issue and all the newer trials are using at least a 10-year follow-up. Technically, how to orient TAVI valves in an anatomic commissure-to-commissure orientation, similar to surgical biologic valves, will be important.
There is a strong emphasis on the need for a multidisciplinary heart team in structural heart interventions. Why is a cardiothoracic surgeon an important part of such a team?
The surgeon has always been a critical member of the heart team for TAVI. Initially, surgeons performed a key role in participating in randomised trials both by deciding who could be randomised to surgery and also in doing the procedure. As we move to lower risk and younger patients, it is imperative to have surgical input on who does and does not fit the randomised trial population, and to consider who might do better with surgical valve replacement, as well as serving as part of the implant team.
What do you feel has been the most important paper published in the past year?
I am very biased but I think the two low risk trials, Evolut Low Risk and Partner 3 were two of the most influential papers in some time. Additionally, MITRA-FR and COAPT have invigorated our approach and thoughts on secondary mitral regurgitation.
How has the COVID-19 pandemic impacted your practice?
I think COVID-19 has impacted us all. We are just coming out of our second surge in Houston. It has impacted who we could treat and slowed both our clinical and our research efforts. The personal, clinical and economic impacts will be felt for a long time.
What are the implications of COVID-19 for the management of patients with heart disease?
COVID-19 has placed a strain on our patients, hospitals and personnel. Many TAVI patients are elderly and part of the population at risk and are hesitant to enter a hospital despite having a life-threatening disease.
Looking back over your career what has been your most memorable case?
My first cardiac autotransplant for cardiac sarcoma of the left atrium. I knew in theory this would work but to do this successfully for the first time was a great thrill. It led to a lifelong interest in this rare and difficult disease.
What advice would you give to someone looking to start a career in medicine?
Medicine is a rewarding way to spend your life. I still wake up each morning excited for what we might do this day. As I near the later part of my career, my greatest problem is that there is still too much to do and too many exciting advances. It is impossible to lose interest or stop.
Outside of medicine, what are your hobbies and interests?
My main interest is family. Like most physicians I spend a lot of time at work. When not at work, I am blessed having a wife of 45 years, two daughters and four grandchildren. I set aside a minimum of at least three weeks every year for family vacation. I have been a runner for many years and was this year excited to see my youngest daughter qualify for and get accepted to run the Boston, New York, Chicago and Berlin marathons just to see them all cancelled due to COVID-19.
- Clinical Professor, Department of Surgery, Baylor College of Medicine
- Clinical Professor of Thoracic Surgery, MD Anderson Cancer Institute
- Professor of Cardiothoracic Surgery, Weill Cornell
- Surgical Director of Structural Heart Disease, The Houston Medical Hospital
- Senior Member, The Methodist Hospital Research Institute
- American Association for Thoracic Surgery
- American College of Cardiology, Fellow
- American Heart Association
- European Association for Cardiothoracic Surgery
- European Society of Cardiology
- International Society for Minimally Invasive Cardiac Surgery
- The Heart Valve Society of America
- BS, Biochemistry, University of Texas at Arlington
- MD, Baylor College of Medicine
- Surgery Residency, Baylor College of Medicine
- Cardiothoracic Surgery Residency, Texas Heart Institute