Warfarin resumption following anticoagulant-associated intracranial hemorrhage: A systematic review and meta-analysis

Background: This study aims to assess the effect of warfarin resumption in patients who experienced warfarin-associated intracranial hemorrhage (ICH). Methods: We conducted a systematic review and meta-analysis of studies evaluating the outcomes of adult patients who survived warfarin-associated ICH. We included studies that compared patients who resumed warfarin versus those who did not. Results: Of 3145 studies screened, ten observational studies were included in the final analysis. Death occurred in 181 of 968 patients (18.7%) who resumed warfarin and 834 of 2579 (32.3%) who did not resume warfarin (RR 0.51, 95% CI 0.34 to 0.76, P = 0.0009). Ischemic stroke occurred in 32 of 902 (3.5%) patients who resumed warfarin and 172 of 2467 (7.0%) patients who did not resume warfarin (RR 0.56, 95% CI 0.39 to 0.82, P = 0.002). Venous thromboembolism occurred in 4 of 224 (1.8%) patients who resumed warfarin and of 33 of 681 (4.8%) patients who did not resume warfarin (RR 0.39, 95% CI, 0.15 to 1.03, P = 0.06). Recurrent ICH occurred in 200 of 2994 (6.7%) patients who resumed warfarin and 358 of 4652 (7.7%) patients who did not resume warfarin (RR 0.89, 95% CI 0.65 to 1.23, P = 0.49). Conclusion: The study suggests that warfarin resumption is associated with significant reduction in ischemic stroke and venous thromboembolism when compared to no warfarin resumption in patients who experience warfarin-associated ICH. Although these results are strongly supportive of restarting anticoagulation, prospective studies are required to confirm our results due to the high likelihood of bias in the included studies.