Abstract 2668: Lacunar Strokes In Patients With Symptomatic Intracranial Stenosis

Abstract

Background and Purpose: Lacunar strokes are conventionally attributed to a distinct microvascular pathophysiology, but the “lacunar hypothesis” has been challenged since some small deep infarcts are identified in patients with sources of cardioembolism or large vessel atherosclerotic disease. We hypothesized that patients with intracranial stenosis with a lacunar stroke presentation would have a lower risk of recurrent stroke than those with an index non-lacunar stroke, and that their recurrent strokes would predominantly be lacunar. Methods: We analyzed subjects enrolled with an index stroke into the Warfarin Aspirin Symptomatic Intracranial Disease (WASID) trial. The index and endpoint strokes were classified as lacunar or non-lacunar by central adjudication. The primary endpoint was recurrent ischemic stroke. Cox proportional hazard models were generated with stratification for severity of stenosis. Results: 347 subjects were enrolled after an index stroke, 38 were lacunar and 309 were non-lacunar. Over a mean follow-up of 1.8 years there was no significant difference in stroke recurrence between patients whose index stroke was lacunar (7/38; 18%) vs. non-lacunar (69/309; 22%) (HR 0.79, 95%CI: 0.36-1.71). Further, no significant differences were found when groups were stratified by 50-69% stenosis (HR 0.50, 95%CI:0.12-2.1) and ≥70% stenosis (HR 0.87, 95%CI: 0.34-2.2) but power was limited. Of the 7 recurrent strokes in patients whose index stroke was lacunar, all 7 were non-lacunar and 3 were in the territory of the stenotic artery. Of the 69 recurrent strokes in patients whose index stroke was non-lacunar, 6 (9%) were lacunar of which 4 were in the territory of the stenotic artery. Conclusions: The risk of recurrent stroke due to intracranial stenosis was similar in patients who presented with lacunar vs. non-lacunar strokes, and all recurrent strokes in patients presenting with lacunar stroke were non-lacunar. These findings suggest that the pathophysiology of index and recurrent strokes in patients presenting with a lacunar stroke and intracranial stenosis is related to the stenosis and not microvascular disease. Therefore, patients with intracranial stenosis who present with lacunar strokes should be included in future trials investigating secondary stroke prevention for symptomatic intracranial stenosis.