ABSTRACT NUMBER: ESOC2026LT76 LT76 - EXTENDING ORAL ANTICOAGULATION TREATMENT AFTER ACUTE CEREBRAL VEIN THROMBOSIS: 24-MONTH RESULTS OF THE EXCOA-CVT CLUSTER-RANDOMIZED TRIAL

Abstract Background and aims After cerebral vein thrombosis (CVT), there is an increased risk of venous thromboembolic events (VTEs), but the optimal duration of oral anticoagulation (OAC) to prevent VTE remains uncertain. Methods EXCOA-CVT (ISRCTN25644448) was a multicenter, prospective study that included both a cluster-randomized trial and a parallel observational study for centers with pre-established OAC policies. The study compared short-term (3-6 months) vs. long-term (12 months) OAC for secondary prevention after CVT, with follow-up at 6, 12, and 24 months. The primary efficacy outcome was symptomatic VTE, including recurrent CVT, at 24 months. Primary safety outcomes included bleeding events and all-cause mortality at 24 months. Study inclusion started in 2014 and was terminated prematurely in December 2023. Results A total of 1257 patients (62.5% female, mean age 39.4±14.1 years) were enrolled from 21 countries. Of these, 448 (35.6%) were in the cluster-randomized trial and 809 (64.4%) in the parallel observational study. In the cluster-randomized trial, 221 patients (49.3%) were assigned to short-term policy and 227 (50.7%) to long-term OAC policy. In the observational arm, 514 (63.5%) were from centres with long-term policy. At 24 months, follow-up data were available for 1,187 patients (94.4%), including 93.8% of patients in the cluster-randomized trial. Final results at 24-months will be presented. Conclusions EXCOA-CVT provides the first evidence on the optimal duration of anticoagulation after CVT from a large cluster-randomised trial, complemented by an observational cohort. We will present 24-month efficacy and safety outcomes, providing critical insights into the balance between recurrent thrombosis and bleeding risk. Conflict of interest