Symptomatic Intracerebral Hemorrhage Among Eligible Warfarin-Treated Patients Receiving Intravenous Tissue Plasminogen Activator for Acute Ischemic Stroke

Objective: To determine whether warfarin-treated patients with an international normalized ratio less than 1.7 who receive intravenous tissue plasminogen activator for acute ischemic stroke are at increased risk for symptomatic intracerebral hemorrhage. Design: Retrospective study. Setting: Academic hospital. Patients: Consecutive patients with acute ischemic stroke who are treated with intravenous tissue plasminogen activator. Main Outcome Measure: Symptomatic intracerebral hemorrhage. Results: One hundred seven patients were included (mean age, 69.2 years; 43.9% men; median National Institutes of Health Stroke Scale score, 14; median onset-to-treatment time, 140 minutes; baseline warfarin use, 12.1%). The median international normalized ratio was 1.04 (range, 0.82-1.61). The overall rate of symptomatic intracerebral hemorrhage was 6.5%, but it was nearly 10-fold higher among patients taking warfarin compared with those not taking warfarin at baseline (30.8% vs 3.2%, respectively; P=.004). Baseline warfarin use remained strongly associated with symptomatic intracerebral hemorrhage (P=.004) after adjusting for relevant covariates, including age, atrial fibrillation, National Institutes of Health Stroke Scale score, and international normalized ratio. Conclusions: Despite an international normalized ratio less than 1.7, warfarin-treated patients are more likely than those not taking warfarin to experience symptomatic intracerebral hemorrhage following treatment with intravenous tissue plasminogen activator. Larger studies in this subgroup are warranted.