Abstract 19119: Concomitant Use of Antiplatelet Therapy with Edoxaban or Warfarin in Patients with Atrial Fibrillation in the ENGAGE AF-TIMI 48 Trial

Abstract

BACKGROUND: Patients with atrial fibrillation (AF) who receive both antiplatelet (AP) and anticoagulant therapy are at markedly higher risk of bleeding. The ENGAGE AF-TIMI 48 trial showed that both the high- (HD) and low-dose (LD) regimens of the once-daily factor Xa inhibitor edoxaban (Edox) were as effective as well-managed warfarin (Warf) (median TTR 68.4%) in preventing stroke or systemic embolism (SEE) with significant reductions in major bleeding and cardiovascular mortality. In this study, we assessed the relative efficacy and safety of Edox as compared with Warf in patients with and without concomitant use of AP therapy. METHODS: This was a randomized, double-blind, double-dummy trial comparing HD (60 mg daily, reduced to 30mg in patients with anticipated increased drug exposure) and LD (30 mg daily, reduced to 15mg) Edox with Warf. Dual AP therapy was prohibited while receiving study drug. Cox proportional hazards models were performed stratified by AP use at 3 months with treatment as a covariate. RESULTS: Of the 21,105 patients, 4,912 (23%) were receiving AP therapy at 3 months (92% aspirin). Patients who received concomitant AP therapy had higher rates of major bleeding compared to patients who did not (Fig). Both Edox regimens had similar relative efficacy in preventing stroke or SEE compared with Warf regardless of concomitant AP use (P int >0.10 for both) with consistent reductions in major bleeding (HD Edox vs. Warf: P int =0.91; LD Edox vs. Warf: P int =0.59). In patients randomized to LD Edox, AP therapy was associated with a further reduction in the net clinical outcome of death, stroke, SEE, or major bleeding (P int =0.02) compared with Warf. CONCLUSIONS: Regardless of concomitant AP therapy, both doses of Edox significantly reduced bleeding compared to well-managed Warf. The safety profile of Edox may be particularly attractive in patients with AF who receive a combination of AP and anticoagulant therapy because of higher absolute risk of bleeding.