[Impact of cerebral microbleeds on outcomes of acute ischemic stroke treated with intravenous thrombolysis].

OBJECTIVE: To assess the impact of cerebral microbleeds (CMBs) on clinical outcomes in patients with acute ischemic stroke treated by intravenous thrombolysis.

METHODS: The clinical data of 225 patients with acute ischemic stroke who received intravenous recombinant tissue plasminogen activator therapy in the Second Affiliated Hospital, Zhejiang University School of Medicine from June 2009 to May 2013 were reviewed. The severity of CMBs and hemorrhagic transformation (HT) after thrombolytic therapy and clinical neurological outcome based on modified Rankin scale (mRS) at 3 months were evaluated. Favorable outcome was defined as mRS 0-1 and unfavorable outcome as mRS 2-6. Multivariate logistic-regression analysis and binary logistic-regression were used to determine independent risk factors of HT and favorable outcome.

RESULTS: The mean age of 225 patients was (66.29±13.01) y, 73 (32.4%) patients were women, mean pretreatment National Institutes of Health Stroke Scale (NIHSS) score was 11.40±5.89, and onset-to-needle time was (238.40±89.16) min. Totally, 522 CMBs were detected in 91 patients (36.1%). Postlytic radiological HT was found in 64 patients (28.4%), among which 43 (19.1%) were hemorrhagic infarction and 21 (9.3%) were parenchymal hematoma. Univariate analysis showed that patients with HT had higher NIHSS score and more incidence of atrial fibrillation and that patients with unfavorable outcome were older and had higher NIHSS score and more CMBs. Multivariate logistic regression analysis showed that multiple CMBs (>=3) was independently associated with parenchymal hematoma (OR=4.957, 95%CI 1.306-18.811, P=0.019), but not with hemorrhagic infarction (OR=1.204, 95%CI 0.386-3.754, P=0.749). Binary logistic regression analysis showed that multiple CMBs (>=3) was independently associated with unfavorable outcome (OR=3.496, 95%CI 1.381-8.849, P=0.008).

CONCLUSION: Multiple CMBs are correlated with parenchymal hematoma and unfavorable neurological outcome after thrombolytic therapy in patients with acute ischemic stroke.