Supplementary Material for: Risk of Intracerebral Hemorrhage After Thrombolysis in Patients with Asymptomatic Hemorrhage on T2*

<b><i>Background:</i></b> Intravenous thrombolysis using the tissue-type plasminogen activator (t-PA) is contraindicated for patients with a history of intracerebral hemorrhage (ICH). T2*-weighted magnetic resonance imaging (MRI) is able to detect asymptomatic ICH. If there is an association between asymptomatic ICH on T2* before t-PA therapy and ICH after t-PA therapy, we may be able to take preventive measures before starting t-PA therapy in patients with MRI-proven hemorrhage. The aim of the present study was to investigate whether asymptomatic ICH seen on T2* increases the risk of new ICH after t-PA therapy. <b><i>Methods:</i></b> Patients who had consecutive stroke treated with t-PA between October 2005 and November 2013 were enrolled. A hypointense T2* signal with a diameter >5 mm was defined as asymptomatic ICH before t-PA therapy. The presence of new ICH at 24 h after t-PA therapy was assessed using T2*. Symptomatic ICH (sICH) was defined as new ICH combined with an increase in the National Institutes of Health Stroke Scale score ≥4. At 3 months after onset, good and poor outcomes were defined as modified Rankin Scale (mRS) scores of 0-1 and 4-6, respectively. <b><i>Results:</i></b> Of 300 patients (age 77 [68-83] years; 173 [58%] males), 25 (8%) had an asymptomatic ICH on T2* before t-PA therapy. Eleven (45%) patients showed an isolated asymptomatic ICH. Three (12%) patients had a round hypointense lesion similar to microbleeds. Nine (36%) patients had a hemorrhagic transformation within a prior infarcted area. Multiple asymptomatic ICHs were seen in 2 (8%) patients. The rates of good and poor outcomes at 3 months were 24 and 59% of patients with asymptomatic ICH and 38 and 41% of patients without asymptomatic ICH (p = 0.300 and 0.202, respectively). At 24 h after t-PA therapy, 11 (44%) of the 25 patients with asymptomatic ICH before t-PA therapy and 87 (32%) of 275 without asymptomatic ICH had new ICH (p = 0.265). Only 1 (4%) of 25 patients with asymptomatic ICH before t-PA therapy and 6 (2%) of 275 without asymptomatic ICH had sICH within 24 h (p = 0.460). On multivariate logistic regression analysis, neither new ICH (odds, 1.19; 95% CI, 0.40-3.54, p = 0.753) nor sICH (odds, 0.95; 95% CI, 0.08-11.90, p = 0.970) was related to asymptomatic ICH on T2* before t-PA therapy. <b><i>Conclusion:</i></b> The presence of T2* hypointensity as a marker of asymptomatic ICH may not be associated with new ICH and sICH after t-PA therapy.