Timing for the Resumption of Anticoagulants after Intracranial Hemorrhage

To identify the ideal timing for resuming oral or injectable anticoagulants therapy after spontaneous intracranial hemorrhage (sICH). We conducted a retrospective cohort study involving 90 patients from a tertiary hospital in Korea, between June 2000 and May 2022, who had experienced sICH while receiving anticoagulant therapy and who resumed treatment within six months. Exclusions were made for trauma-induced hemorrhages and early post-ictus fatalities. The interval between sICH occurrence and anticoagulant resumption was the main exposure variable. We evaluated hemorrhagic and thromboembolic events as outcomes. Multivariate analysis was used to determine the risk factors for post-resumption complications. Receiver operating characteristic (ROC) and locally estimated scatterplot smoothing (LOESS) were used to identify optimal timing. The median patient age was 71 years, with 56.7% male. Warfarin was the most commonly used anticoagulant prior to sICH (63.3%), and non-vitamin K antagonist oral anticoagulants (NOACs) were used in 22.2%. Within six months of resuming anticoagulants, 9 patients experienced hemorrhagic and 13 experienced ischemic complications. Age ≥80 years was significantly associated with ischemic events (OR 4.29, p=0.048), while NOAC use was strongly associated with hemorrhagic complications (OR 16.59, p=0.003). ROC analyses suggested possible cut-off points for anticoagulants resumption at day 30 for ischemic risk and day 7.5 for hemorrhagic risk, though AUC values were not statistically significant. Risk modeling using LOESS curves indicated that the combined complication risk was lowest when anticoagulants were resumed between days 20 and 22 after ictus. The findings suggest that approximately 3 weeks after sICH is the optimal time to resume anticoagulants, minimizing the risk of rebleeding or thromboembolic events. These findings may inform clinical decision-making in a broad patient population, though individualized assessment remains essential.