Year in Review: Low-Risk TAVR Trials Big in 2019, but QoL Data Impresses, Too

The expanded indication for transcatheter aortic valve replacement to include severe symptomatic patients at low risk for surgery was the biggest highlight in the field of structural heart disease this year, experts say, but it was far from the only one.

PARTNER 3 and the Evolut Low-Risk Study showed that TAVR was at least as good as surgery for low-risk patients, if not better, and led to a greenlight from the US Food and Drug Administration this summer. But a couple of substudies looking at improvements in quality of life with TAVR, as well as with the MitraClip (Abbott) in patients with functional mitral regurgitation, also impressed.    

To TCTMD, Megan Coylewright, MD (Dartmouth-Hitchcock Heart and Vascular Center, RI), said TAVR has reached a point where rates of the gold-standard endpoint of stroke and mortality are “historically low,” which allows physicians to shift attention toward “softer” endpoints like health status and quality of life.

“Now we can start to think that maybe these other outcomes aren’t so soft,” she commented.

The PARTNER 3 quality-of-life substudy, presented by Suzanne Baron, MD (Lahey Hospital & Medical Center, Burlington, MA), at TCT 2019, was an important contribution to the field, said Coylewright, noting that the results were released on the main stage and not shunted off to an obscure part of the convention center. The substudy showed that TAVR was associated with both early and late health status benefits compared with surgery.

“These are people who do care if they live a long time and live stroke-free,” Coylewright said, highlighting the slightly younger ages of patients included in the low-risk trials. “But because the rates of stroke and mortality are so low, [health status] becomes really important. You can’t differentiate the therapies—TAVR and SAVR—by the stroke or death rates, but the health status questions [posed to patients], which are really powerful, did show a difference.”

COAPT Quality-of-Life Data

In the same vein, Coylewright also highlighted the quality-of-life analysis from COAPT as another achievement in 2019, as did Chandan Devireddy, MD (Emory University School of Medicine, Atlanta, GA).

“When it comes to what we’re trying to achieve with these patients, quality of life is a very impactful variable and an issue that is potentially the most important for our congestive heart failure patients,” Devireddy told TCTMD. “Obviously, survival trumps everything, but it’s one thing to be alive with horrible heart failure. If you can live longer, reduce hospitalizations, and feel better—and MitraClip has borne this out over time—that speaks volumes to the potential for this therapy in selected patients.”

Obviously, survival trumps everything, but it’s one thing to be alive with horrible heart failure. Chandan Devireddy

The COAPT study was similar to some of the early TAVR studies in that these patients were at high-to-prohibitive risk for surgery, said Coylewright. Given their advanced symptomatic heart failure, increasing life span here is less important than improvements in quality of life, she said.

“It really drives decision-making,” said Coylewright, referring to the quality-of-life analysis. “In fact, in the commercial world with MitraClip, that’s how we’ve proceeded. Even though MitraClip did result in a mortality benefit, we’re really talking to patients about quality of life because that’s what’s most important to them.”

Low-Risk Trials Change the Game

Regarding the FDA approval of TAVR for low-risk patients, Devireddy said it has certainly altered practice at his institution, where they’ve started incorporating decision-making models more often to help them explain the data, and options, to patients.

“We’ve had to change our game,” he said. “I think the patients we’re seeing in clinic are very different than who we were seeing 2 years ago. We’re really trying to pay attention to what we consider high-risk features for TAVR, but honestly, most patients when they hear about TAVR, or have already done their own research on it, are seeking out transcatheter-based therapies.”

They’re in my office to accomplish a specific goal they have in mind and think TAVR is the way to get there. Megan Coylewright

Coylewright told TCTMD that there are patients who come in requesting TAVR, so it’s critical to educate them about the two options while factoring in their treatment goals. “They’re not in my office to get a TAVR,” said Coylewright. “They’re in my office to accomplish a specific goal they have in mind and think TAVR is the way to get there. If I can connect their goal with the therapy, I haven’t had pushback from patients.”

In terms of 2019 highlights, Devireddy also pointed to a study by Sreekanth Vemulapalli, MD (Duke University Medical Center, Durham, NC), that has implications for the expanded TAVR indication. In that study, investigators showed that institutional and operator procedural volume remained inversely associated with 30-day risk-adjusted mortality even after accounting for a potential learning curve. These data are particularly relevant in light of the national coverage determination (NCD) from the Centers for Medicare & Medicaid Services (CMS) that mandates volume requirements for centers with and without TAVR experience, he said.

“With the low-risk approval also comes the NCD change,” said Devireddy. “That’s going to greatly alter the playing field and dynamics of who patients see and where they go to have their aortic stenosis treated. There’s differing opinions on this, of course, and there are some elements to suggest access to care might be limited and that there might be underserved populations. On the flip side, there does seem to be this persistent relationship between institutional and operator volume and TAVR outcomes.”

Devireddy said that as the NCD kicks in and new centers emerge, it will be important to determine if the volume-outcome relationship continues to manifest and, if it does, what type of enforcement will be available to regulate centers so that they get their numbers in line.