Background To investigate the effectiveness and safety of withholding or restarting antithrombotic agents, and different antithrombotic therapies among patients with atrial fibrillation post-intracranial hemorrhage. Methods and Results This is a nationwide retrospective cohort study involving patients with atrial fibrillation receiving antithrombotic therapies who subsequently developed intracranial hemorrhage between January 1, 2011 and December 31, 2017. The risk of ischemic stroke (IS), recurrent intracerebral hemorrhage (ICH), and all-cause mortality were investigated between patients receiving no treatment versus patients reinitiating oral anticoagulants (OACs) or antiplatelet agents, and warfarin versus non-vitamin K antagonist OACs. We applied inverse probability of treatment weighting to balance the baseline characteristics and Cox proportional hazards model to estimate the hazard ratios (HRs) of different outcomes of interest. Compared with no treatment, OACs reduced the risk of IS (HR, 0.61; 0.42-0.89), without increase in the risk of ICH (1.15, 0.66-2.02); antiplatelet agent users showed a similar risk of IS (1.13, 0.81-1.56) and increased risk of ICH (1.81, 1.07-3.04). Use of OACs or antiplatelet agents did not reduce the risk of all-cause mortality (0.85, 0.72-1.01; and 0.88, 0.75-1.03, respectively). Compared with warfarin, non-vitamin K antagonist OAC users showed a similar risk of IS (0.92, 0.50-1.70), non-significantly reduced risk of ICH (0.53, 0.22-1.30), and significantly reduced all-cause mortality (0.60, 0.43-0.84). Conclusions OACs are recommended in patients with atrial fibrillation and intracranial hemorrhage because they reduced the risk of IS with no increase in the risk of subsequent ICH. Non-vitamin K antagonist OACs are recommended over warfarin owing to their survival benefits.
Keywords: antiplatelet therapy; antithrombotic therapy; atrial fibrillation; intracerebral hemorrhage; oral anticoagulant therapy.