SAMMPRIS Supports Aggressive Medical Management Over Stenting to Treat Intracranial Artery Stenosis

September 7, 2011—Findings from the SAMMPRIS (Stenting vs Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis) trial were published by Marc I. Chimowitz, MBChB, et al online ahead of print in The New England Journal of Medicine. The background of the study is that atherosclerotic intracranial arterial stenosis is increasingly being treated with percutaneous transluminal angioplasty and stenting (PTAS) to prevent recurrent stroke but that PTAS has not been compared with medical management in a randomized trial.

As detailed in The New England Journal of Medicine, patients who had a recent transient ischemic attack or stroke attributed to stenosis of 70% to 99% of the diameter of a major intracranial artery were randomly assigned to aggressive medical management alone or aggressive medical management plus PTAS with the use of the Wingspan stent system (Stryker Corporation, Kalamazoo, MI). Stryker acquired Boston Scientific Corporation's (Natick, MA) neurovascular business, including the Wingspan stent system, in January 2011. The primary endpoint was stroke or death within 30 days after enrollment or after a revascularization procedure for the qualifying lesion during the follow-up period or stroke in the territory of the qualifying artery beyond 30 days.

According to the SAMMPRIS investigators, enrollment was stopped after 451 patients underwent randomization because the 30-day rate of stroke or death was 14.7% in the PTAS group (nonfatal stroke, 12.5%; fatal stroke, 2.2%) and 5.8% in the medical management group (nonfatal stroke, 5.3%; nonstroke-related death, 0.4%) (P = .002). Beyond 30 days, stroke in the same territory occurred in 13 patients in each group. The mean duration of follow-up, which is ongoing, currently is 11.9 months. The probability of the occurrence of a primary endpoint event over time differed significantly between the two treatment groups (P = .009), with 1-year rates of the primary endpoint in the PTAS group of 20% and 12.2% in the medical management group.

The investigators concluded that in patients with intracranial arterial stenosis, aggressive medical management was superior to PTAS with the use of the Wingspan stent system, both because the risk of early stroke after PTAS was high and because the risk of stroke with aggressive medical therapy alone was lower than expected.

Also online ahead of print in The New England Journal of Medicine, Joseph P. Broderick, MD, addresses the SAMMPRIS findings and the challenges of intracranial revascularization for stroke prevention. Dr. Broderick discusses three key issues raised by the SAMMPRIS trial and previous trials of revascularization for stroke prevention: (1) the challenges of intracranial revascularization are greater than those of revascularization of extracranial carotid stenoses; (2) aggressive and attentive medical therapy is an effective approach to the prevention of stroke in high-risk populations; and (3) the critical roles of the US Food and Drug Administration and Centers for Medicare & Medicaid Services in the advancement of cost-effective medicine.