Study Shows Positive Impact of FDA Approval and Medicare Coverage on CAS Outcomes

December 3, 2013—Findings from an evaluation of the impact of US Food and Drug Administration (FDA) regulatory approval and Centers for Medicare and Medicaid Services (CMS) coverage on outcomes of carotid artery stenting (CAS) have been published online ahead of print by William A. Gray, MD and Patrick Verta, MD, in Catheterization and Cardiovascular Interventions.

Dr. Gray and Dr. Verta concluded that declines in periprocedural death and stroke rates in CAS appear linked to regulatory and coverage approvals leading to increased operator experience, continued regulatory oversight, and insights into the introduction of other novel therapies.

The background of the study noted that CAS was introduced in the United States nearly a decade ago as a novel treatment of severe carotid stenosis and that voluminous and high-quality prospective data permit analysis of longitudinal trends in CAS outcomes.

As summarized in Catheterization and Cardiovascular Interventions, outcomes from all prospective trials with FDA oversight from 2000 to 2011 were reviewed, as were the subset of studies using a single CAS system. All studies shared common inclusion/exclusion criteria, endpoints, independent assessment/adjudication of neurological events, and were conducted in accordance with FDA regulations. Death and stroke rates from FDA-approved studies in high-surgical-risk patients were assessed.

Between 2000 and 2011, two distinct periods with clustered and differentiated outcomes in CAS investigational device exemption trials were observed, separated by FDA approval and CMS coverage in 2004 to 2005. The mean 30-day death and stroke rate in the first wave (2000 to 2004) of CAS trials was 5.3% (95% CI, 4.6–6.2%), and fell significantly to 2.6% (95% CI, 1.9–3.7%; P = .0001) in the second wave (2006 to 2011). This decline occurred during a simultaneous, independent 24-fold increase in monitored CAS activity. This decline in death and stroke rates was observed in both symptomatic and asymptomatic patients, independent of device tested, reported Drs. Gray and Verta.