Presumed safe no more: lessons from the Wingspan saga on regulation of devicesBMJ 2014; 348 doi: https://doi.org/10.1136/bmj.g93 (Published 22 January 2014) Cite this as: BMJ 2014;348:g93
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Two recent articles published in the BMJ have criticized the US Food and Drug Administration (FDA) for the approval of the Wingspan stent used for intracranial stenting (ICS) to prevent recurrent stroke despite insufficient evidence of its effectiveness. Moreover, they further draw attention to FDA’s inadequate response to emergence of randomized controlled trial evidence in the SAMMPRIS trial that demonstrated that intracranial angioplasty and stenting more than doubled the risk of stroke or death within 30 days compared with medical management alone in patients who had a recent stroke or transient ischemic attack.
We share these concerns and would like to draw attention to additional evidence that we published in 2013, regarding adoption of this technology and its outcomes in 100% Medicare population during 2006 to 2010, a period following approval of this device in the setting of inadequate evidence and prior to availability of randomized controlled trial evidence (1). We found limited adoption of the technology during that time when a total of 826 Medicare Fee-for-Service beneficiaries received ICS, although the overall hospitalization rate for ICS increased significantly, from 1 per 1 000 000 person-years (n=35 procedures) in 2006 to 9 per 1 000 000 person-years (n=258 procedures) in 2010 (P=0.009 for trend; Figure 1). After controlling for age, sex, and race, the risk-adjusted IRR that represents the relative annual change in the ICS hospitalization rate was 1.72 (95% confidence interval [CI], 1.69 to 1.76). Procedure rates were higher in men than in women, and were highest among patients aged 75 to 84 years and lowest among those ≥85 years. We attributed this limited adoption of ICS to a highly restrictive reimbursement policy by the Centers for Medicare & Medicaid Services (CMS) as they provided coverage for this procedure only in the context of a randomized trial. After this decision in 2006, CMS maintained this judgment despite a petition for broader coverage filed in 2008 by Boston Scientific. We drew comparison to endovascular devices for mechanical embolectomy in acute stroke patients that were approved through the FDA’s 510(k) pathway and are fully reimbursed by CMS, leading to a much more rapid rate of increase in their use in recent years(2). Our study group may have included some patients from SAMMPRIS, but the number is likely to have been small given that there were only 224 patients, with an average age of 61.0 years, recruited into the ICS arm of SAMMPRIS; whereas our study included 826 patients with an average age of 75.0 years.
We further demonstrated that the 30-day mortality rate increased from 2.9% in 2006 to 12.9% in 2010 (P=0.1 for trend), and the 1-year mortality rate increased from 14.7% to 19.5% during the same time, P=0.01; however, the annual changes were not significant after adjustment. Our database did not allow comparison with patients who received medical management alone, restricting any conclusion regarding safety or efficacy of this procedure. It is unfortunate that even nine years after approval, uncertainty remains regarding the safety and effectiveness of the device in patients who are refractory to medical therapy, even as the harm demonstrated by SAMMPRIS has justified the cautious approach taken by CMS. The device continues to be available in the market with only a safety communication issued by FDA in 2012. Nine years after approval, a post-market surveillance study by Stryker Corp is still pending.
1. Gupta A, Desai MM, Kim N, Bulsara KR, Wang Y, Krumholz HM. Trends in intracranial stenting among medicare beneficiaries in the United States, 2006-2010. Journal of the American Heart Association. Apr 2013;2(2):e000084.
2. Khatri P, Adeoye O, Kleindorfer DO. US rates of mechanical embolectomy for acute ischemic stroke treatment are increasing. Stroke 2010;41(4):e361. abstract.
Competing interests: No competing interests