TAVR trial promises wider care, more questions

Device trial opens to low-risk aortic stenosis patients, while an aging population makes for an uncertain future.
March 6th, 2017

 

A TAVR procedure at UCH in May 2015 during the trial of the Sapien 3 device for intermediate-risk patients. John Carroll is center.

Five years ago, UCHealth University of Colorado Hospital joined a revolution in cardiac care. Interventional cardiologists and cardiothoracic surgeons worked together to replace narrowed, calcified aortic valves in two patients. That in itself was unremarkable; millions of patients have had their worn-out valves replaced with new ones. The breakthrough was the method of the procedure.

A year before, the two patients would not have been on the table. They were considered too high risk for traditional open-heart surgery and would have had no options other than medication management. But they got another choice with the development of transcatheter aortic valve replacement, or TAVR. Rather than opening the chest, the specialists threaded a catheter through the femoral artery and used a special device to deliver and place a new aortic valve.

These patients and hundreds who followed them had much shorter recovery times than open-heart patients, but more importantly they gained a new measure of hope that they might not only live longer but also better.

One of those first two TAVR patients at UCH described the toll her heart disease took. Rarely could she leave her apartment, she recounted.

“I lived within those four walls except to go to the doctor,” she said. “I was existing. I wasn’t living.”

Two years later, UCH joined a national trial of a new generation of TAVR devices, this one aimed at moderate-risk patients. Having helped to open the door to FDA approval for that group of patients, the hospital is now part of yet another TAVR trial, this one aimed at low-risk aortic valve disease patients. The first such procedure, trialing a device from Medtronic, was Feb. 15. UCHealth Medical Center of the Rockies performed its first TAVR procedure for a low-risk patient, using a device from Edwards Lifesciences, last August.

John Carroll, MD, director of Interventional Cardiology at UCHealth University of Colorado Hospital, says clinicians will face tough choices in the years to come about using TAVR.

“These are both major pivotal trials and it is spectacular that two UCHealth hospitals are in the vanguard,” said John Carroll, MD, director of Interventional Cardiology at UCH. “And these trials will have a major impact on clinical practice.”

After the revolution

Carroll noted that TAVR has already transformed treatment of heart disease in the half-decade since it emerged – and not only from a clinical standpoint.

“In inoperable, high-risk and now intermediate-risk patients, TAVR has taken over as the predominant form of therapy,” he said. The next challenge is to figure out the consequences of that change and to answer the thorny questions it poses, Carroll said.

One concern is cost. On the one hand, TAVR patients generally spend 24 to 48 hours in the hospital after their procedures and recover in about a week – far less than the five hospital days and six weeks of recovery open-heart patients can expect. But the delivery system and the valve  from manufacturers Edwards Lifesciences and Medtronic alone cost about $30,000, Carroll said, far more than traditional surgical valves, which run roughly $5,000 or $6,000.

The differences require balancing the up-front costs with savings at the back end and the even more difficult-to-quantify improvements in quality of life. But for patients whose aortic disease is inoperable, the problem is even knottier.

That’s because some prohibitively high-risk patients treated with TAVR “clearly don’t benefit,” Carroll said. That opens the door to hard decisions for those considering the treatment, including weighing, for example, the benefits of palliative care over surgery, he said.

Data for decisions

A growing body of data helps to guide the discussions. In 2012, the Society of Thoracic Surgeons and the American College of Cardiology launched a Transcatheter Valve Therapy Registry to collect data on patients who have undergone TAVR. Carroll as well as Fred Grover, MD, of the University of Colorado School of Medicine’s Department of Surgery, have served as members of the registry’s national steering committee, which is composed of four cardiologist and four surgeons.

UCH is a site for the clinical trial of the Medtronic CoreValve Evolut R System. It’s one of two devices being tested for use in TAVR procedures on patients with severe aortic stenosis who are at low risk for open-heart surgery. (Graphic courtesy Medtronic.)

Hospitals submit information on mortality, length of stay, complications, bleeding and more, said Kimberly Marshall, RN, CPHQ, AACC, clinical quality specialist with the Cardiac & Vascular Center at UCH. As of January, the hospital had provided data to the registry on some 400 TAVR patients, Marshall said.

“We’ve learned a lot from the registry and there is more to learn as this treatment evolves,” Carroll said, notably predicting who is likely to have good outcomes from TAVR and who is not. For example, “a significant portion” of those with renal failure and COPD in addition to aortic stenosis will die within one year after a TAVR procedure, the data show. That makes for discussions that are “exceedingly challenging,” Carroll said.

“The data raise both ethical questions and issues of cost and benefit to society,” he said. “The dicey issue is that we do not have a perfect ‘crystal ball’ to use in decision making with individual patients in terms of  predicting who will be alive and improved at one year versus who will be dead or still feeling ill at one year.”

The next wave

The importance of patient selection only promises to increase because of a brew of nature and demographics. The most common cause of aortic stenosis, Carroll said, is aging. Think of the aortic valve as a vital piece of anatomic machinery. In an 80-year-old, that part will have opened and closed roughly 3 billion times. In many people of that age or older – more than 5 percent, Carroll said – aortic stenosis will begin to break it down.

Couple that fact with an aging and populous group of baby boomers – defined as those born between 1946 and 1964 – and the result promises to be what Carroll dubbed “the second TAVR tsunami” in an editorial comment that appeared last October in the Journal of the American College of Cardiology.

An X-ray image from the first patient treated in the low-risk TAVR trial at UCH. It shows a 34 mm valve, which was successfully implanted in an otherwise healthy 83-year-old patient. The procedure team included physicians John Carroll, John Messenger, David Fullerton, Joseph Cleveland, Javier Valle, and Tamas Seres with the nursing and technical staff from the operating room and cardiac catheterization laboratory. (Image courtesy John Carroll.)

“A substantial increase in the volume of TAVR patients is likely to parallel the increase in the elderly population, especially with the arrival of the baby boomers after 2020,” Carroll wrote. He noted that the 35,000 TAVR procedures performed in the United States in 2016 conceivably could quadruple by 2020.

Whatever the number it will include many with aortic stenosis made frail because of a long list of conditions that will very high surgical risks or truly inoperable, Carroll said. Demographics and registry data will combine to force discussions of how to make decisions about providing TAVR and other expensive treatments to people with poor prognoses in a society with limited resources. There will be no clear or easy answers.

“The questions will be how to draw the line and who will draw it,” Carroll said.

Carroll noted in his editorial that the link between aging and degenerative aortic valve disease makes it unlikely that the average age of TAVR patients will significantly decline even if TAVR is approved for lower risk patients. Still, the fact that moderate- and low-risk patients will have access to the treatment raises another question. How long will the new valves last in younger patients who can generally be expected to live longer after their procedures than those in the older, higher-risk group?

“One of the major unanswered questions we have now is about the long-term durability of the valves – that is, beyond five to 10 years,” Carroll said. The answers could come from CT scans of patients in each of the low-risk TAVR trials. “We will want to see how the valve leaflets are working for both surgical and TAVR patients at 10 years and beyond,” he said.

The march of medical and information technology only underscores the primacy of an individual’s decision about his or her health care, Carroll said.

“We can inform patients with our data, predictions and personal recommendations for care,” he said. “But I have found in sitting down with them and their families that they are often very wise. Helping them to define their own goals of care is hugely important in deciding whether TAVR is appropriate for them or not.”

About the author

Tyler Smith is a freelance writer based in metro Denver.