Restarting Anticoagulant Therapy After Intracranial Hemorrhage: A Systematic Review and Meta-Analysis

Background and purpose: The safety and efficacy of restarting anticoagulation therapy after intracranial hemorrhage (ICH) remain unclear. We performed a systematic review and meta-analysis to summarize the associations of anticoagulation resumption with the subsequent risk of ICH recurrence and thromboembolism.

Methods: We searched published medical literature to identify cohort studies involving adults with anticoagulation-associated ICH. Our predictor variable was resumption of anticoagulation. Outcome measures were thromboembolic events (stroke and myocardial infarction) and recurrence of ICH. After assessing study heterogeneity and publication bias, we performed a meta-analysis using random-effects models to assess the strength of association between anticoagulation resumption and our outcomes.

Results: Eight studies were eligible for inclusion in the meta-analysis, with 5306 ICH patients. Almost all studies evaluated anticoagulation with vitamin K antagonists. Reinitiation of anticoagulation was associated with a significantly lower risk of thromboembolic complications (pooled relative risk, 0.34; 95% confidence interval, 0.25-0.45; Q=5.12, P for heterogeneity=0.28). There was no evidence of increased risk of recurrent ICH after reinstatement of anticoagulation therapy, although there was significant heterogeneity among included studies (pooled relative risk, 1.01; 95% confidence interval, 0.58-1.77; Q=24.68, P for heterogeneity <0.001). No significant publication bias was detected in our analyses.

Conclusions: In observational studies, reinstitution of anticoagulation after ICH was associated with a lower risk of thromboembolic complications and a similar risk of ICH recurrence. Randomized clinical trials are needed to determine the true risk-benefit profile of anticoagulation resumption after ICH.