Aggressive medical management maintained its advantage over intracranial stenting in a long-term analysis of SAMMPRIS trial data. The absolute risk reduction from medical treatment was 9 percent at three years, according to results published online Oct. 26 in The Lancet.
SAMMPRIS (Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis) compared percutaneous transluminal angioplasty and stenting plus aggressive medical management with aggressive medical management alone in patients with recent transient ischemic attack or stroke and 70 percent to 99 percent stenosis of a major intracranial artery.
A total of 227 patients underwent aggressive medical management that included aspirin, clopidogrel (Plavix, Bristol Myers-Squibb/Sanofi Aventis), management of primary risk factors such as cholesterol levels and blood pressure and a lifestyle modification program. Another 224 patients received the Wingspan stent system (Stryker Neurovascular, formerly Boston Scientific Neurovascular) and aggressive medical management.
The primary endpoint was stroke or death within 30 days after enrollment, ischemic stroke in the territory of the qualifying artery after 30 days of enrollment and stroke or death within 30 days of revascularization during follow-up.
Enrollment closed early when data indicated that stenting was associated with more strokes and death. Early results showed that the stenting group had a 30-day rate of stroke or death of 14.7 percent vs. 5.8 percent in the medical management group.
Researchers revised their plans for follow-up to two years after enrollment of the last patient, for a period of Nov. 25, 2008 to March 11, 2011. At a median follow-up of 32.4 months, 15 percent of patients in the medical management group experienced a primary endpoint event vs. 23 percent in the stenting group. Medical management held its advantage at one year (12.6 percent vs. 19.7 percent), two years (14.1 percent vs. 20.6 percent) and three years (14.9 percent vs. 23.9 percent).
“Although we cannot rule out the possibility that longer follow-up would have shown less benefit from medical treatment alone, we think this possibility is unlikely because there was no suggestion that the efficacy gap between the two groups narrowed over time—the absolute risk reduction from medical treatment was 8.9 percent at 30 days and 9.0 percent at three years,” wrote Colin P. Derdeyn, MD, of the University of Washington School of medicine in St. Louis, and colleagues.
The medical management group in SAMMPRIS experienced a much lower rate of stroke than was seen in the WASID (Warfarin–Aspirin Symptomatic Intracranial Disease) trial, Derdeyn et al pointed out. They attributed that to SAMMPRIS’ strategy to use dual antiplatelet therapy.
The authors also addressed concerns that SAMMPRIS’ aggressive medical management protocol might be difficult to adhere to in real-world practice. “Blood pressure and LDL-C [low-density lipoprotein cholesterol] were managed by study coordinators and neurologists who followed the study's risk factor management algorithms,” they wrote. “These algorithms are available elsewhere and could easily be used in practice. Provision of a lifestyle management programme to patients with stroke is not yet routine care.”
Patients who don’t respond to medical management remain at high risk of stroke, though, and are in need of new treatments, they added.