Transcatheter aortic valve replacement (TAVR), a minimally invasive approach to valve replacement that delivers a bioprosthetic valve to the heart via catheters inserted through the groin or chest, is a standard of care for the treatment of aortic stenosis. Since the first TAVR procedure was performed in 2002 in France, millions of people have had the procedure globally, and over 100,000 procedures are performed in the U.S. annually.
Physicians and surgeons at NewYork-Presbyterian and Columbia have been advancing TAVR for over two decades, helping the procedure evolve into the standard of care for the treatment of aortic stenosis.
Over the past two decades, cardiologists, interventional cardiologists, and cardiac surgeons at NewYork-Presbyterian and Columbia have been at the forefront of advancing TAVR into the game-changing procedure it is today, led by interventional cardiologist Martin Leon, M.D., chief innovation officer and the director of the Cardiovascular Data Science Center for the Division of Cardiology at NewYork-Presbyterian and Columbia.
Dr. Martin Leon leads NewYork-Presbyterian and Columbia’s efforts to advance TAVR.
“NewYork-Presbyterian has played a pivotal role at every stage during the development and further refinement of TAVR, and is an acknowledged leader in the concepts, therapies, and treatment paradigms of modern-era valvular heart disease therapy,” says Dr. Leon. “Right now, we expect that about 70% of patients with aortic stenosis who will need an aortic valve replacement will get it using TAVR versus surgically.”
“We saw the promise of the therapy early on and witnessed remarkable turnarounds in patients who had no other options,” adds Susheel Kodali, M.D., director of the Structural Heart and Valve Center at NewYork-Presbyterian and Columbia. “We learned and we helped educate the community and the industry, and that led to device iteration, procedure iteration, and patient selection changes that helped drive the field forward.”
Proving the Promise of TAVR Through Clinical Trials
NewYork-Presbyterian and Columbia’s involvement with TAVR began in 2005, when it became one of three clinical sites in the U.S. chosen to conduct the first feasibility trial of a percutaneous aortic valve that was an early iteration of the heart valve used in TAVR. The expertise and reputation of the heart team at Columbia, including the long-standing collaboration between cardiology led by Dr. Leon and cardiac surgery led by surgeon-in-chief Craig Smith, M.D., led to its involvement in the pivotal multicenter Placement of Aortic Transcatheter Valve (PARTNERS) clinical research studies that would help prove the efficacy of TAVR and lead to FDA approvals.
“We led a series of landmark randomized control trials over the course of more than 10 years, with more than 10,000 patients in different risk categories, to see if TAVR was better than watchful waiting, as good as or better than surgery, and in which patient cohorts,” says Dr. Leon. Below is an overview of the PARTNER studies:
- The first PARTNER study, published in 2010, found that TAVR, over standard therapies, improved survival and reduced symptoms in patients with severe aortic stenosis who weren’t candidates for surgery.
- In 2011, PARTNER data published in the New England Journal of Medicine demonstrated that high-risk patients with severe aortic stenosis undergoing TAVR had survival rates similar to patients receiving surgery. That year, the FDA also approves a TAVR device for use in high-risk patients for the first time, supported by evidence from the PARTNER trial and the CoreValve/Evolut trials.
- In the PARTNER 2 study, which was published in 2016, TAVR was also found to be effective for patients with an intermediate risk of death or serious complications from surgery, with outcomes similar to surgical patients.
- In 2019, PARTNER 3 researchers found that low-risk patients who underwent TAVR had a 46% reduction in risk of death, stroke, or hospitalization for a heart-related problem or surgical complication, compared with patients who underwent surgery. This paved the way for the expansion of FDA approval to low-risk patients.
The most recently published TAVR research, led by co-principal investigator Allan Schwartz, M.D., chief of the Division of Cardiology at NewYork-Presbyterian and Columbia, focused on the early use of TAVR in patients with asymptomatic severe aortic stenosis. The findings could mean significant changes in patient care, because TAVR is usually not performed until symptoms are apparent. Called the EARLY TAVR trial, the study found that compared to those in the surveillance group, unplanned hospitalization was cut in half among the early TAVR patients.
“When you wait for symptoms to express themselves, patients get sick and develop irreversible cardiac changes,” says Dr. Leon. “That was the premise of the EARLY TAVR study, and the results were positive, suggesting that one in five patients would have benefit from earlier treatment. We think that EARLY TAVR is going to set a course for earlier treatment of severe valvular heart disease.”
Improving and Building Upon TAVR Technology
NewYork-Presbyterian and Columbia physicians are also committed to improving upon TAVR delivery systems and other technologies that help lower the risk of complications from the procedure, such as stroke or paravalvular leak. Their findings, published in major publications, have led to a dramatic decrease in vascular complications, improved imaging and assessment of valve function, and approval of devices for vascular closure.
Another ongoing effort has focused on developing longer-lasting replacement valves. “Bioprosthetic valves have a lifespan. We've been working with others on new forms of valve tissue that would allow these valves to be more durable,” says Dr. Leon. “My dream is to develop one valve for life that we can insert in a patient at a relatively early stage, and it can perform the way it should without late structural deterioration.”
Isaac George, M.D., co-director of the Structural Heart and Valve Center at NewYork-Presbyterian and Columbia, recently led a trial of a polymer mitral valve that showed significant promise. It’s part of a strategy to provide longitudinal management of people with valve diseases, as younger patients are getting the technology. “We need to account for how we're going to take care of patients over their lifetime,” says Dr. George.
Dr. Isaac George and Dr. Susheel Kodali (pictured, left to right) lead the Structural Heart and Valve Center at NewYork-Presbyterian and Columbia, where the concept of the multidisciplinary heart team was pioneered.
The institution has also taken the lead in evaluating adjunctive devices that complement the primary procedure, Dr. Leon says. In 2017, NewYork-Presbyterian and Columbia physicians were the senior authors of an international study of a device that helps capture and remove embolic debris, which can increase risk for stroke.
“We're now working on new generations of protection devices,” says Dr. Leon. “It's one among many things that we've done to try to make TAVR easier, safer, more generalizable, and available to practicing physicians.”
New Paradigms of Care
TAVR requires a coordinated, collaborative approach involving interventional cardiologists, cardiac surgeons, echocardiographic imaging specialists, nurses, and sometimes cardiac anesthesiologists. Concomitant with clinical trials, NewYork-Presbyterian and Columbia pioneered and formalized the concept of the multidisciplinary heart team.
“When we first started treating patients, it was very clear that a team approach was going to be necessary for obtaining the kind of outcomes and quality that we wanted,” says Dr. George, one of a handful of surgeons who performs both open cardiac surgery as well as percutaneous- and transcatheter-based procedures. “The kind of knowledge that cardiac surgeons have is very different and complementary to the kind of knowledge that a cardiologist brings, for instance. We needed to bring everyone together to achieve the best outcomes for patients.”
“The work done at NewYork-Presbyterian and Columbia has changed the entire treatment paradigm for aortic stenosis,” adds Rebecca Hahn, M.D., director of interventional echocardiography at the Structural Heart and Valve Center. “We highlight the importance of imaging and the imager in these procedures. It was highly unusual for an echocardiographer to be participating full-time in interventional procedures.”
Dr. Hahn was one of the first interventional echocardiographers, now a formal subspecialty of imaging and an essential part of the heart team.
Prior to the development of TAVR, imagers were rarely needed in interventional procedures except to diagnose acute post-procedural complications. This changed with TAVR, where procedures were performed with transesophageal echocardiographic guidance. NewYork-Presbyterian and Columbia’s Structural Heart and Valve Center was the first to recognize this novel role of the imager and the expertise required to guide complex structural procedures. The imager on the heart team also plays an important role throughout the patient journey and is integral to the initial diagnosis of aortic stenosis, assessment of anatomic criteria for device choice, procedural guidance, and post-TAVR follow-up. Dr. Hahn became one of the first interventional echocardiographers, now a formal subspecialty of imaging, and runs an interventional echocardiography fellowship that trains one to three fellows a year.
“We have been involved in one way or another with every aspect of the continuity of care for TAVR patients,” says Dr. Leon. “We helped innovate the concept of the heart valve clinic and what the workup should be that is the least burdensome for patients, post-procedural care, and how to interact with referring doctors and guide them in both surveillance and how to work with heart team clinics.”
As a pioneer in TAVR, NewYork-Presbyterian and Columbia has also been central to training physicians in the procedure. “When we introduced the first device in 2010 at Columbia, we trained 50% of the sites in the US,” says Dr. Leon. “The fact that the technique could be so generalizable allowed it to be disseminated very widely to the medical community, which is something we're very proud of.”
Such a history of trailblazing relies on strong institutional support. “NewYork-Presbyterian is an environment where you can push, learn, understand, review, make mistakes, learn from them, and then take the learnings forward,” says Dr. Kodali.
“In the beginning, we never thought that we could achieve the outcomes that we have with TAVR,” adds Dr. Leon. “But over the course of years, we were able to innovate many changes —and those changes have been transformative.”
Listen to Dr. Leon and Dr. Smith discuss the early days of launching the PARTNER trials and development of TAVR on the Advances in Care podcast.
