Abstract 54: Incidence And Predictors Of Dural Arteriovenous Fistulae After Cerebral Venous Sinus Thrombosis: Analysis Of ACTION-CVT

Background: Intracranial dural arteriovenous fistulae (DAVF) are uncommon vascular anomalies with a reported incidence of 0.2 per 100,000 person years. An association between cerebral venous thrombosis (CVT) and DAVF has been reported; however, the direction of causality between the two remains uncertain. We aimed to identify the incidence and predictors of development of DAVF among patients with CVT. Methods: This is a post-hoc analysis of Anticoagulation in the Treatment of Cerebral Venous Thrombosis (ACTION-CVT), a multicenter retrospective study comparing outcomes of CVT patients treated with warfarin versus direct oral anticoagulants (DOACs) from 2015 to 2020. Patients were included in this analysis if they did not have DAVF on initial imaging and had follow-up vascular imaging during the study. Clinical, imaging, and anticoagulation characteristics of patients who developed DAVF were compared to those who did not. Stepwise binary logistic regression including important variables (achieving p Results: A total of 751 patients (median age 43, 66% female) met inclusion criteria of whom 13 (1.7%) developed DAVF with an estimated rate of 2.40 per 100 patient years. Patients with DAVF were less likely to have headache at presentation (53.8% vs 79.3%, p=0.037), but more likely to have no venous recanalization on follow-up imaging (46.2% vs 14.8%, p=0.008), baseline cortical vein thrombosis (15.4% vs 2.7%, p=0.053), and received warfarin (vs. DOACs) as initial oral anticoagulant (84.6% vs 58.7%, p=0.085) but the latter two missed the statistical significance threshold. In stepwise binary logistic regression analysis, cortical vein thrombosis (OR 7.98, 95% CI 1.40-45.35, p=0.02) and lack of venous recanalization (OR 4.93, 95% CI 1.48-16.39, p=0.01) were associated with development of DAVF. Conclusion: In this large multicenter study of CVT, the incidence of DAVF development was higher than the previously reported rate in the general population. The presence of cortical vein thrombosis and lack of venous recanalization were associated with increased risk of development of DAVF.