Epidemiology and Biostatistics Publications
Long-Term Outcomes of Ischemic Stroke of Undetermined Mechanism: A Population-Based Prospective Cohort
Document Type
Article
Publication Date
12-1-2017
Journal
Neuroepidemiology
Volume
49
Issue
3-4
First Page
160
Last Page
164
URL with Digital Object Identifier
10.1159/000482019
Abstract
Background and Purpose: Little is known about the short-and long-term outcomes of ischemic stroke of undetermined mechanism (ISUM). Methods: Subjects were recruited from the Mashhad Stroke Incidence Study. Ischemic stroke (IS) was classified on the basis of the TOAST criteria. We further categorized patients with ISUM into ISUM (negative clinical/test results for large artery, small artery) and ISUM (incomplete investigations). Cox proportional hazard models and the competing-risk regression model were used to compare 1 and 5 years mortality (all-causes) and recurrent rate among IS subtypes. Results: Overall, 1-year mortality was higher in those with ISUM than in ISUM (adjusted hazard ratio [aHR] 1.6, 95% CI 1.01-2.8; p = 0.04) and in other stroke subtypes. Cardioembolic stroke was associated with the greatest risk of stroke recurrence at one year (aHR 4.9, 95% CI 1.8-12.9; p = 0.001) and 5 years (HR 2.1, 95% CI 1.1-3.7; p = 0.01) as compared to ISUM . Conclusions: The classification of ISUM as a single group may lead to over-or underestimation of mortality and recurrence in this major category of IS. A better definition of ISUM is necessary to predict death and recurrence accurately. neg inc inc neg neg