Anticoagulants Resumption after Warfarin-Related Intracerebral Haemorrhage: The Multicenter Study on Cerebral Hemorrhage in Italy (MUCH-Italy)

Whether to resume antithrombotic treatment after oral anticoagulant-related intracerebral haemorrhage (OAC-ICH) is debatable. In this study, we aimed at investigating long-term outcome associated with OAC resumption after warfarin-related ICH, in comparison with secondary prevention strategies with platelet inhibitors or antithrombotic discontinuation. Participants were patients who sustained an incident ICH during warfarin treatment (2002-2014) included in the Multicenter Study on Cerebral Hemorrhage in Italy. Primary end-point was a composite of ischemic stroke/systemic embolism (SE) and all-cause mortality. Secondary end-points were ischemic stroke/SE, all-cause mortality and major recurrent bleeding. We computed individual propensity score (PS) as the probability that a patient resumes OACs or other agents given his pre-treatment variables, and performed Cox multivariable analysis using Inverse Probability of Treatment Weighting (IPTW) procedure. A total of 244 patients qualified for the analysis. Unlike antiplatelet agents, OAC resumption was associated with a lower rate of the primary end-point (weighted hazard ratio [HR], 0.21; 95% confidence interval [CI], 0.09-0.45), as well as of overall mortality (weighted HR, 0.17; 95% CI, 0.06-0.45) and ischemic stroke/SE (weighted HR, 0.19; 95% CI, 0.06-0.60) with no significant increase of major bleeding in comparison with patients receiving no antithrombotics. In the subgroup of patients with atrial fibrillation, OACs resumption was also associated with a reduction of the primary end-point (weighted HR, 0.22; 95% CI, 0.09-0.54), and the secondary end-point ischemic stroke/SE (weighted HR, 0.09; 95% CI, 0.02-0.40). In conclusion, in patients who have an ICH while receiving warfarin, resuming anticoagulation results in a favorable trade-off between bleeding susceptibility and thromboembolic risk.