Wait time guidelines needed for Transcather Aortic Valve Implementation

June 3, 2014 (Toronto, ON) – A new study in the Canadian Journal of Cardiology suggests that modest delays in receiving transcatheter aortic valve implementation (TAVI) for severe aortic stenosis could have a substantial impact on the effectiveness of treatment.

Aortic stenosis is a narrowing of the aortic valve opening that restricts normal blood flow to the body. Patients are typically older and often have other health issues, making them high risk for conventional surgery. TAVI has emerged as the preferred treatment for these patients as the replacement valve is implanted through a small incision in the groin or between the ribs, eliminating the need for a large chest incision. There is, however, a lack of data about what is an acceptable wait time for patients deemed as good candidates for TAVI.

A team of investigators from the University of Toronto and the Institute for Clinical Evaluative Sciences in Toronto have used mathematical modeling with the results from a landmark randomized trial, Placement of Aortic Transcatheter Valves (PARTNER), to look what happens when TAVI wait times are increased. Even modest increases in wait times were found to have a substantial impact on how effective TAVI is in otherwise inoperable patients and high-risk surgical candidates.

“To our knowledge, our study is the first to evaluate the effect of delayed access to TAVI, and provides insight into the importance of wait time and outcomes,” says lead investigator Dr. Harindra Wijeysundera, interventional cardiologist at Sunnybrook’s Schulich Heart Centre and assistant professor at the University of Toronto. “Creating benchmarks for appropriate wait times should be a priority.”

Although TAVI would result in fewer deaths in patients deemed inoperable regardless of wait time, the magnitude of benefit decreased dramatically. In the high-risk surgical candidates, at TAVI wait times beyond 60 days, TAVI was less effective on average compared with conventional surgery.

“Our findings have implications on care delivery for severe aortic stenosis patients who are TAVI candidates. Because of the importance of wait-time monitoring, ideally detailed information should be collected on the time of referral for TAVI work-up, the time at which diagnostic work-up is complete, and the time at which a patient is accepted for the procedure,” says Dr. Wijeysundera. “Data on delays in any of these intervals should be made available to programs in a timely fashion, such that cases can be triaged. This is especially important for the patients deemed as good candidates for surgery. The clinical decision of when high-risk surgery is preferable over TAVI should incorporate the program’s current TAVI wait time, and the associated potential wait-time mortality.”