Combination antithrombotic therapy and bleeding risk: Comparing atrial fibrillation and venous thromboembolism

Document Type

Conference Proceeding

Publication Date


Publication Title

Vascular Medicine


Background: Existing studies regarding combination anticoagulant- antiplatelet management have focused on patients with atrial fibrillation (AF). It is unknown if the combination of anticoagulant-antiplatelet therapy presents a comparable risk of bleeding for patients with venous thromboembolism (VTE).

Methods: Adult patients initiating warfarin at six anticoagulation clinics in Michigan from 2009 to 2020 were enrolled via a registry-based cohort study. Participants were stratified based on sole indication for anticoagulation: AF or VTE. Two propensity score-matched cohorts were generated based on demographics, comorbidities, antiplatelet use, and follow-up time. Survival analysis and Cox proportional hazards were used to examine adverse events.

Results: Propensity score matching generated two wellbalanced cohorts of 1593 patients each. Bleeding risk was significantly higher in patients treated for VTE compared to AF (see Fig.). After adjusting for the number of antiplatelet agents, being anticoagulated for VTE remained significantly associated with increased bleeding risk (hazard ratio: 1.23; 95% CI: 1.08-1.42).

Conclusion: Patients anticoagulated for VTE have a significantly higher bleeding risk compared to similarly matched patients with AF. As most guidelines regarding antithrombotic management have focused on patients with AF, further research is needed to tailor these recommendations to the unique VTE population.





First Page