By Matthew E. Fink, MD

Professor and Chairman, Department of Neurology, Weill Cornell Medical College; Neurologist-in-Chief, New York Presbyterian Hospital

Dr. Fink reports he is a consultant for Procter & Gamble and Pfizer.

SOURCE: Kwon HM, et al. Frequency, risk factors, and outcome of coexistent small vessel disease and intracranial arterial stenosis: Results from the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) Trial. JAMA Neurol 2015; Nov 30. doi:10.1001/jamaneurol.2015.3145 [Epub ahead of print].

The SAMMPRIS trial investigated the consequences of medical vs endovascular therapy for the treatment of symptomatic intracranial atherosclerosis, but the trial was terminated early because of the high rate of complications in the endovascular arm. The medical arm included intensive medical therapy with lifestyle modifications, use of statins, and dual antiplatelet therapy, and this resulted in an unexpected low rate of recurrent stroke in the medical arm. The investigators then performed a post-hoc analysis of 451 participants to ascertain the prevalence and associated risk factors of small vessel disease as it relates to known intracranial atherosclerosis of large vessels. A total of 313 participants had baseline brain MRI imaging and, of those, 49.5% had small vessel disease based on the presence of lacunar infarction, high-grade white matter hyperintensities, or microbleeds. Variables that were significantly more prevalent in the small vessel disease group, compared to the others, were advanced age, higher systolic blood pressure, higher glucose level, and lower Montréal Cognitive Assessment score. Additional significant variables were the number of patients with diabetes mellitus, coronary artery disease, or stroke before the qualifying event. Although there was an association between the presence of small vessel disease and any ischemic stroke, small vessel disease was not associated with an increased risk of stroke in the territory of the affected atherosclerotic large vessel. This study points out the high prevalence of coexisting small vessel disease with large vessel atherosclerosis, but it did not clarify any of the mechanisms or etiologies for small vessel disease, which are many and varied.