Factors associated with the presence of cerebral microbleeds and its influence on outcomes of stroke not treated with alteplase

Objectives: Cerebral microbleeds (CMB) are associated with increased risk of hemorrhagic transformation (HT) of ischemic stroke with alteplase. Whether the presence of CMB influences the risk of HT and discharge outcomes of stroke patients not receiving alteplase is unclear. We evaluated the factors associated with the presence of CMB, and if the rates of HT and discharge outcomes were modified by the presence of CMB among stroke patients not treated with alteplase. Methods: Ischemic stroke patients who had MRI and did not receive alteplase were included in the study. CMB, HT and white matter hyperintensity (WMH) were evaluated using Microbleed Anatomical Rating Scale, Heidelberg bleeding classification, and Fazekas scales, respectively. Multivariate regression analysis was performed to evaluate factors associated with the presence of CMB. Results: Among 196 patients in the study, 58 (30%) patients had CMB. Nine patients had >= 10 CMBs. Median National Institutes of Health stroke scale score was 4. In multivariate analysis, age (OR=1.07;95% CI=1.01-1.12), history of stroke (OR=3.10;95%CI=1.08-8.92), congestive heart failure (OR=7.26;95% CI=1.58-33.42), admission diastolic blood pressure (OR=1.03;95%CI=1.003-1.06) and severe WMH defined as Fazekas score 4-6 (OR=4.69;95%CI=1.80-12.23) were significantly associated with the presence of CMB. There was no difference in HT (10% vs 12%, p = 0.80) or discharge outcomes (modified Rankin Scale 0-2: 53% vs 57%, p = 0.62) of patients with CMB compared to those without CMB. Conclusion: CMB are associated with severe WMH and higher diastolic blood pressure. CMB are not associated with the HT occurrence or discharge outcome of mild ischemic stroke in the absence of alteplase.