Outcomes-Based Measurement of TAVR Program Quality Goes Live

Mitchel L. Zoler

March 30, 2020

The long-sought goal of measuring the quality of U.S. transcatheter aortic valve replacement (TAVR) programs by patient outcomes rather than by the surrogate measure of case volume is about to be realized.

Starting more or less immediately, the U.S. national register for all TAVR cases that's mandated by Food and Drug Administration labeling of these devices and run through a collaboration of the American College of Cardiology and the Society of Thoracic Surgeons will start applying a newly developed and validated five-item metric for measuring 30-day patient outcomes and designed to gauge the quality of TAVR programs.

At first, the only recipients of the data will be the programs themselves, but starting in about a year, by sometime in 2021, the STS/ACC TVT (transcatheter valve therapy) Registry will start to make its star-based rating of TAVR programs available to the public, Nimesh D. Desai, MD, said on March 29 at the joint scientific sessions of the ACC and the World Heart Federation. The meeting was conducted online after its cancellation because of the COVID-19 pandemic.

These societies already make star-based ratings of U.S. programs available to the public for several other types of cardiac interventions, including coronary artery bypass surgery and MI management.

The new, composite metric based on 30-day outcome data "is appropriate for high-stakes applications such as public reporting," said Dr. Desai, a thoracic surgeon and director of thoracic aortic surgery research at the University of Pennsylvania in Philadelphia. "We're confident this model can be used for public reporting. It's undergone extensive testing of its validity." The steering committee of the STS/ACC TVT Registry commissioned development of the metric, and it's now "considered approved," and ready for use, he explained.

To create the new metric, Dr. Desai and his associates used data from 52,561 patients who underwent transfemoral TAVR during 2015-2017 at any of 301 U.S. sites. These data came from a total pool of more than 114,000 patients at 556 sites, but data from many sites weren't usable because they were not adequately complete.

The researchers then identified the top four measures taken during the 30 days following intervention (hospitalization included) that best correlated with 1-year survival and patients' quality-of-life scores on the Kansas City Cardiomyopathy Questionnaire: stroke; major, life-threatening, or disabling bleed; acute kidney injury (stage III); and moderate or severe paravalvular leak. These outcomes "matter most to patients," Dr. Desai said.

They used these four outcomes plus 30-day mortality to calculate the programs' ratings. Among the 52,561 patients, 14% had at least one of these adverse outcomes. The researchers then used a logistic regression model that adjusted for 46 measured variables to calculate how each program performed relative to the average performance of all the programs.

Programs with outcomes that fell within the 95% confidence intervals of average performance were rated as performing as expected; those outside rated as performing either better or worse than expected. The results showed 34 centers (11%) had worse than expected outcomes and 25 (8%) had better than expected outcomes, Dr. Desai said.

"This is a major step forward in measuring TAVR quality," commented Michael Mack, MD, a cardiac surgeon with Baylor Scott & White Health in Dallas who has been very active in studying TAVR. "Until now, we used volume as a surrogate for quality, but the precision was not great. This is an extremely welcome metric." The next step is to eventually use 1-year follow-up data instead of 30-day outcomes, he added.

"With the rapid expansion of TAVR over the past 6-8 years, we're now at the point to start to do this. It's an ethical obligation This will be one of the most high-fidelity, valid models for public reporting" of clinical outcomes," said Joseph Cleveland, MD, a professor of surgery at the University of Colorado at Denver in Aurora. "It's reassuring that about 90% of the program performed as expected or better than expected," he added.

"Transparency and outcomes should drive how TAVR is delivered," commented Ashish Pershad, MD, an interventional cardiologist at Banner-University Medicine Heart Institute in Phoenix who estimated that he performs about 150 TAVR procedures annually. "This is a step forward. I've been waiting for this for a long time. Until now, volume has been used as a surrogate outcome, but we know it's not accurate. I'm confident that this model is a good starting point."

But Dr. Pershad also had concern that this new approach "can lend itself to some degree of gaming," like a bleeding event getting classified as minor when it was really major, or outlier patients getting dropped from reports.

The temptation to cut corners may be higher for TAVR than it's been for the cardiac-disease metrics that already get publicly reported, like bypass surgery and myocardial infarction management, because of TAVR's higher cost and higher profile, Dr. Pershad said. Existing measures "have not been as linked to financial disincentive as TAVR might be" because TAVR reimbursements can run as high as $50,000 per case. "The stakes with TAVR are higher," he said.

Ultimately, the reliable examination of TAVR outcomes that this new metric allows may lead to a shake-up of TAVR programs, Dr. Pershad predicted. "This is clearly a step toward closing down some programs that [consistently] underperform."

The STS/ACC TVT Registry receives no commercial funding. Dr. Desai has been a consultant to, speaker on behalf of, and received research funding from Gore, and he has also spoken on behalf of Cook, Medtronic, and Terumo Aortic. Dr. Cleveland, Dr. Mack, and Dr. Pershad had no disclosures.

American College of Cardiology 2020 Scientific Session (ACC.20)/World Congress of Cardiology: Presented March 29, 2020.

This article originally appeared on MDedge.com.

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