Abstract T MP35: Frequency, Risk Factors, and Impact of Coexistent Small Vessel Disease in the SAMMPRIS Trial

Abstract

Background: Intracranial atherosclerotic stenosis (ICAS) and small vessel disease (SVD) may coexist. We investigated the frequency and risk factors for SVD in SAMMPRIS patients and the impact of SVD on stroke recurrence in the medical arm of the trial. Methods: Of 451 patients enrolled in SAMMPRIS, 313 had baseline brain MRIs read centrally for SVD. SVD was defined by any of the following: old lacunar infarction, Fazekas score of 2-3 for white matter hyperintensities, or microbleeds. We compared risk factors in patients with vs. without SVD using Fisher’s exact test (for percentages), independent groups t test (for means) or Wilcoxon rank sum test (for medians), and compared the survival curves of patients with vs. without SVD in the medical arm for ischemic stroke in the territory of the stenotic artery and any ischemic stroke using the logrank test. Results: Of the 313 patients, 161 (51.4%) had SVD on the baseline MRI. Variables that were significantly (p<0.05) higher in patients with SVD were age, diabetes, lipid disorder, baseline SBP, coronary disease, and old infarct in the territory. The Kaplan-Meier curves in the figure show that patients with SVD were at significantly higher risk of any ischemic stroke (p = 0.048) but not stroke in the territory (p = 0.10) compared with patients without SVD. Conclusion: SVD in patients with ICAS is common, especially in patients who are older, diabetic, hyperlipidemic, and have higher SBP. Patients with ICAS and coexistent SVD are at higher risk of any ischemic stroke but may not be at higher risk for stroke in the territory.