A single institution’s experience with using dabigatran, rivaroxaban and warfarin for prevention of thromboembolism in atrial fibrillation

Background: Although non-vitamin K antagonist oral anticoagulants (NOACs) are approved for stroke prevention in atrial fibrillation (AF) patients, their use in the local clinical setting has not been well studied. This study aims to evaluate the clinical outcomes of dabigatran, rivaroxaban and warfarin in a tertiary hospital in Singapore. Methods: This is a retrospective cohort study with one-year follow-up. A total of 383 patients recruited between June 2011 and December 2014 were studied. Incidents of stroke, systemic embolism and clinically relevant bleeding events were compared between dabigatran, rivaroxaban and warfarin. Results: Stroke rates were 5.47% per year with warfarin, 7.27% per year with dabigatran (HR=1.32; 95% CI 0.48−3.64; p=0.591) and 2.76% per year with rivaroxaban (HR=0.49; 95% CI 0.14−1.69; p=0.261). The warfarin group had significantly higher incidence of minor bleeding (62.4% vs 3.64% for dabigatran vs 13.79% for rivaroxaban; p<0.001), major bleeding (3.91% for warfarin, 0.91% for dabigatran, 0% for rivaroxaban; p=0.028) and other adverse events (51.18% for warfarin, 3.64% for dabigatran, 8.28% for rivaroxaban; p<0.001). Incidence of dyspepsia was higher in both NOAC groups compared to warfarin (0% for warfarin, 7.27% for dabigatran, 5.52% for rivaroxaban; p=0.003). Conclusion: Stroke and venous thromboembolism rates after one year were comparable among dabigatran, rivaroxaban and warfarin. Warfarin was associated with more bleeding and adverse events while both NOACs were associated with higher rates of dyspepsia. Further study is needed to assess the clinical benefit of NOACs in the Singaporean population.