Background: For patients with atrial fibrillation and history of intracranial hemorrhage (ICH), the risk of further ICH and the benefit of antithrombotic agents for stroke risk reduction remain unclear.
Study design: Retrospective cohort study.
Setting: National Health Research Institutes, Taiwan.
Synopsis: Using the National Health Insurance Research Database in Taiwan, researchers identified 307,640 patients with atrial fibrillation and a CHA2DS2-VASc score >/= 2. Of this group, 12,917 patients with a history of ICH were identified and separated into three groups: no treatment, antiplatelet treatment, or warfarin. Among the no treatment group, the rate of ICH and ischemic cerebrovascular accident were 4.2 and 5.8 per 100 person-years, respectively. Among patients on antiplatelet therapy, the rates were 5.3% and 5.2%, respectively. Among patients on warfarin, the number needed to treat (NNT) for preventing one ischemic stroke was lower than the number needed to harm (NNH) for producing one ICH among patients with a CHA2DS2-VASc score >/= 6. In patients with lower CHA2DS2-VASc scores, the NNT was higher than NNH.
Bottom line: Treatment with warfarin may benefit patients with atrial fibrillation and prior ICH with CHA2DS2-VASc scores >/= 6, but risk likely outweighs benefit in patients with lower scores.
Citation: Chao TF, Liu CJ, Liao JN, et al. Use of oral anticoagulants for stroke prevention in patients with atrial fibrillation who have a history of intracranial hemorrhage. Circulation. 2016;133(16):1540-1547.