Abstract 172: Does SAMMPRIS Support Stenting Compared to Medical Therapy for Subpopulations of Patients with Intracranial Arterial Stenosis?

Abstract

Objectives: To determine whether SAMMPRIS supported the use of stenting compared to medical therapy alone to prevent recurrent stroke in subpopulations of patients with symptomatic intracranial arterial stenosis. Methods: The primary outcome, 30-day stroke and death and later strokes in the territory of the qualifying artery, was compared in those with and without baseline factors in the two treatment arms, percutaneous transluminal angioplasty and stenting (PTAS) plus aggressive medical therapy (AMM) vs. AMM alone. Baseline factors included gender, age (<60 or ≥60 years), race (white or black), diabetes, hypertension, lipid disorder, smoking status, type of qualifying event (QE) (TIA, non-penetrator stroke or penetrator stroke), QE hypoperfusion symptoms (related to either change in position, exertion or recent change in antihypertensive), use of antithrombotic or proton pump inhibitor at baseline, days to enrollment (≤7 or >7), old infarcts in the same territory, percent stenosis (<80% or ≥80%), other artery stenosis and location of the symptomatic artery (internal carotid, middle cerebral, vertebral or basilar; and anterior or posterior). The subgroup analyses were conducted by fitting a Cox proportional hazards regression model that included treatment, treatment by time, the factor, and the treatment by factor interaction (p-value for which is reported). Results: A total of 451 patients were enrolled, 227 randomized to AMM and 224 to PTAS. Of all variables evaluated, the observed 2-year event rates were higher with PTAS than with AMM in the vast majority and the interaction with treatment was not statistically significant for any of the factors (Table). Conclusions: The SAMMPRIS results do not support the use of PTAS compared to medical treatment in any examined subpopulation of patients with symptomatic intracranial stenosis, including those with QE hypoperfusion symptoms.