Cerebral Microbleeds and the Risk of Incident Ischemic Stroke in CADASIL (Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy)

Background and Purpose— Cerebral microbleeds are associated with an increased risk of intracerebral hemorrhage. Recent data suggest that microbleeds may also predict the risk of incident ischemic stroke. However, these results were observed in elderly individuals undertaking various medications and for whom causes of microbleeds and ischemic stroke may differ. We aimed to test the relationship between the presence of microbleeds and incident stroke in CADASIL (Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy)—a severe monogenic small vessel disease known to be responsible for both highly prevalent microbleeds and a high incidence of ischemic stroke in young patients. Methods— We assessed microbleeds on baseline MRI in all 378 patients from the Paris–Munich cohort study. Incident ischemic strokes were recorded during 54 months. Survival analyses were used to test the relationship between microbleeds and incident ischemic stroke. Results— Three hundred sixty-nine patients (mean age, 51.4±11.4 years) were followed-up during a median time of 39 months (interquartile range, 19 months). The risk of incident ischemic stroke was higher in patients with microbleeds than in patients without (35.8% versus 19.6%, hazard ratio, 1.87; 95% confidence interval, 1.16–3.01; P =0.009). These results persisted after adjustment for history of ischemic stroke, age, sex, vascular risk factors, and antiplatelet agents use (hazard ratio, 1.89; 95% confidence interval, 1.10–3.26; P =0.02). Conclusions— The presence of microbleeds is an independent risk marker of incident ischemic stroke in CADASIL, emphasizing the need to carefully interpret MRI data.