Risk of thromboembolism, recurrent hemorrhage, and death after warfarin therapy interruption for intracranial hemorrhage

Background Whether and when to resume oral anticoagulant therapy for patients who survive warfarin-related intracranial hemorrhage (ICH) remains a dilemma lacking consensus recommendations and high-quality evidence to guide clinical decision making. Objective To determine the incidences of recurrent ICH, thrombosis, and death in relation to resumption or non-resumption of warfarin therapy during the 365 days after incident ICH. Methods We conducted a retrospective cohort study of adult patients in an integrated healthcare delivery system who were receiving warfarin therapy at the time of incident (index) ICH between 1/1/2000 and 12/31/2007 and survived to hospital discharge. The primary outcomes were recurrent ICH, thrombosis (stroke, systemic embolism, and venous thromboembolism), and all-cause mortality during the 365 days following index ICH. Patients were assigned to one of two groups defined by warfarin therapy resumption after the index ICH. Results There were 160 patients discharged from the hospital following warfarin-related index ICH; of these 54 (33.8%) resumed warfarin therapy and 106 (66.2%) did not. Recurrent ICH occurred in a numerically greater, but statistically non-significant, proportion of patients who did not resume warfarin therapy (7.6% vs. 3.7%, p = 0.497). Similarly, patients who did not resume warfarin had a three-fold higher (12.3% vs. 3.7%, p = 0.092) and approximately two-fold higher (31.1% vs. 18.5%, p = 0.089) rates of thrombosis and all-cause mortality, respectively, during follow up. Conclusion Resumption of warfarin therapy following warfarin-associated ICH appeared not to be associated with increased risk of recurrent ICH but trended toward reduced thrombosis and all-cause mortality.