Controls pose challenge in ACC/STS trial

A report in the April 17 issue of the Journal of the American Medical Association offered another glimpse into a clinical trial to evaluate expanded uses of transcatheter aortic valve replacement (TAVR). In what is likely the first of its kind, the study is being conducted by the American College of Cardiology (ACC) and the Society of Thoracic Surgeons (STS).

The FDA granted an investigational device exemption to the two medical societies in February, paving the way for Medicare reimbursement for alternative access approaches for patients with severe aortic stenosis in the ACC/STS trial.  

The trial is expected to enroll inoperable patients to be treated with TAVR using various access sites. The primary outcomes include 30-day major adverse cardiac and cerebrovascular events. Secondary outcomes are events and one-year mortality, according to clinicaltrials.gov, and mortality, stroke, stroke or transient ischemic attack, major vascular complications, valve related dysfunction requiring re-intervention, incident renal replacement therapy, life-threatening bleeding, and high-degree aortic valve block requiring permanent pacemaker implantation at 30 days.

The trial is an observational cohort study that will use the TVT Registry, which was developed and is maintained by the medical societies. JAMA writer Mike Mitka, MSJ, noted that the control group for safety data will be high-risk patients who underwent TVR and the control group for efficacy data will be inoperable patients who received medical treatment.

“The control groups, which are not ideal, makes it difficult for the FDA to assess whether the results of this trial, if they are positive, give the agency enough confidence to approve expanding TAVR,” he wrote.