Risk of Intracranial Hemorrhage among Patients with Acute Ischemic Stroke Receiving Warfarin and Treated with Intravenous Tissue Plasminogen Activator: Xian Y, Liang L, Smith EE, et al. JAMA 2012;307:2600–8.

Abstract

The authors of this retrospective observational study analyzed national data from the American Heart Association “Get with the Guidelines–Stroke Registry” to determine the safety of tissue plasminogen activator (tPA) administration for acute ischemic stroke in patients on prior warfarin therapy with an international normalized ratio (INR) of 1.7 or lower. The main outcome measure studied was symptomatic intracranial hemorrhage (sICH), with secondary outcome measures of systemic hemorrhage, any tPA complication, or in-hospital mortality. Of 23,437 total patients receiving tPA in the Registry, a total of 1802 (7.7%) patients were on warfarin before admission. Compared to their non-warfarin peers, these patients tended to have more comorbidities, and after adjustment for these characteristics the authors found no difference in primary or secondary outcomes between the two groups. Furthermore, the authors found no correlation between INR level (at or below 1.7) and sICH risk among patients on warfarin receiving tPA. The authors concluded that there is sufficient evidence to back American Heart Association guidelines that allow for the use of tPA for acute ischemic stroke in warfarin-treated patients with an INR≤1.7.