Expert Consensus Document on TAVR Provides ‘Roadmap’ for Clinicians

On the heels of the United States Food and Drug Administration’s (FDA) November 2011 approval of the first prosthetic device for use in transcatheter aortic valve replacement (TAVR), an expert task force has published a consensus document to examine the current state of evidence and provide clinicians with important guidance on appropriate use of the new technology.

The document, which was released online January 30, 2012, ahead of print in the Journal of the American College of Cardiology, is endorsed by multiple professional societies including the American College of Cardiology (ACC) Foundation, the American Association for Thoracic Surgery (AATS), the Society for Cardiovascular Angiography and Interventions (SCAI), and the Society of Thoracic Surgeons (STS). It serves as a detailed follow-up to the joint position statement from ACC and STS released in late 2011.

With PARTNER being the only randomized study examining TAVR, writing committee vice chair Sanjay Kaul, MD, of Cedars-Sinai Medical Center (Los Angeles, CA), told TCTMD in a telephone interview that much of the data regarding TAVR outcomes has come from registry studies. Dr. Kaul said he and his colleagues set out to create “a roadmap for the practicing physician to ensure judicious use and to ensure rational dispersion and careful post-marketing scrutiny.”

Complex Procedure Calls for Cautious Protocol

In order to provide a “critical appraisal of the evidence,” Dr. Kaul said the writing committee focused on several issues they considered significant. First, the document highlights the importance of careful patient selection and a team-based approach, given the complexity of the procedure. Also, they write that TAVR is best performed at specialized heart centers equipped with hybrid operating rooms and/or modified cath labs.

Dr. Kaul stressed the issue of incorporating patients’ values and judgments into the risk/benefit assessment prior to TAVR and determining how physicians can best communicate with patients during this process.

“Patients exhibit a remarkable range of preferences with respect to their willingness to trade short-term risk for long-term gain or to trade the duration of survival for the quality of survival,” he said. “For example, if you have an octogenarian with significant comorbid conditions, they’re more likely to trade off avoidance of disabling stroke than decreased mortality. We believe that a framework that incorporates patients’ values and preferences is likely to be more effective.”

The last main point of the consensus document is a call for ongoing evaluation and participation in a national TAVR registry. Dr. Kaul said the registry, begun in December 2011 and sponsored jointly by ACC and STS, will help “to track outcomes in the real world as well as the patterns of use, because one of the challenges is to be able to reproduce the results of the randomized clinical trials in real-world clinical practice.” Dr. Kaul and colleagues also suggest that linking reimbursements to registry participation may increase the usefulness of the registry down the line.

Potential Confounders

A few remaining issues surrounding TAVR warrant further examination. “Stroke is likely going to be the Achilles’ heel of this technology,” Dr. Kaul said, noting that so far increased stroke rates have only been seen with the first-generation TAVR devices.

Going forward, Dr. Kaul said lingering questions revolve around:

• The impact of embolic protection devices on stroke
• The role of improved profiles of newer generation devices
• The impact of a formal protocol of antithrombotic therapy on stroke

There also is concern that there might be a trend toward TAVR use in lower risk patients, Dr. Kaul said, adding that even though patients considered ‘low risk’ have a lower risk of mortality, they have the same risk of stroke.

“The benefit/risk balance in the lower-risk patients may not be as desirable,” he said. “So we have to wait for the right types of studies to provide us with the right evidence to be able to move to lower-risk patients.”

Another issue is “the need for new pacemakers,” Dr. Kaul said, suggesting that lower profile devices may solve this problem. “There’s a concern that these devices are associated with paravalvular aortic regurgitation and we know from previous data that leaks that are significant are a predictor of late mortality, but we don’t have the data.” Durability, he added, may become an issue.

Lastly, Dr. Kaul said cost-effectiveness will come into play as TAVR use becomes more widespread. Questions about the procedure being cost-effective across a spectrum of at-risk patients and society’s role in paying for it have already been raised, he said.

“The bottom line is that this is a potentially transformational technology but we have to be very careful in applying this to the right patient at the right time and at the right place,” he concluded. “That’s critical.”

 

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Source:
Holmes DR, Mack MH, Kaul S, et al. 2012 ACCF/AATS/SCAI/STS Expert Consensus Document on Transcatheter Aortic Valve Replacement. J Am Coll Cardiol. 2012;Epub ahead of print.

 

 

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