Edoxaban vs warfarin in vitamin K antagonist experienced and naive patients from the edoxaban versus warfarin in subjects undergoing cardioversion of atrial fibrillation (ENSURE-AF) randomized trial

Background: In the ENSURE-AF study (NCT 02072434), the oral factor Xa inhibitor edoxaban showed a similar efficacy and safety profile vs enoxaparin- warfarin (enox-warf) in patients undergoing electrical cardioversion of nonvalvular atrial fibrillation. Methods: This prespecified ancillary analysis examined the efficacy and safety of edoxaban vs enox-warf in patients who were vitamin K antagonist (VKA) naïve or experienced at the time of randomisation in the ENSURE-AF study. The primary efficacy endpoint was a composite of stroke, systemic embolic event (SEE), myocardial infarction (MI), and cardiovascular death analysed during the overall study period, 28 days on study drug after cardioversion + 30 days follow-up. The primary safety endpoint was the composite of major and clinically relevant nonmajor bleeding analysed during the on-treatment period from the time of first dose to last dose of study drug taken + 3 days. (Figure Presented) Results: Of 2,199 patients enrolled in ENSURE-AF, 1,095 were randomised to edoxaban and 1,104 to enox-warf. Mean age was 64±10 years and 64.2±11 years, respectively. Baseline characteristics were similar for patients who were VKA naïve and experienced vs the comparative edoxaban treatment arm. There were fewer primary efficacy endpoint events with edoxaban than enox-warf in VKA experienced or naïve. There were no significant differences in bleeding rates regardless of treatment or VKA experience (Table). Conclusion: In the ENSURE-AF study, edoxaban had comparable efficacy and safety to optimized usual anticoagulation with enox-warf. The primary efficacy endpoint outcomes were not significantly different between patients who were VKA experienced or naïve.