Abstract 15740: Concomitant Use of Dronedarone and Direct Oral Anticoagulants and Risk of Bleeding in Patients With Atrial Fibrillation: An Analysis of the U.S. Truven Health MarketScan Database

Abstract

Introduction: Dronedarone (DR), a P-gp and CYP 3A4 inhibitor may increase exposure and the risk of bleeding when combined with direct oral anticoagulants (DOACs). Objective: To examine the association between concomitant use of DR and the DOACs, apixaban (A), dabigatran (D), and rivaroxaban (R), and risk of bleeding compared to DOAC monotherapy in patients with atrial fibrillation (AF). Methods: A retrospective cohort study using a U.S. claims database, Truven Health MarketScan identified new users of A, D, and R in patients with AF ≥18 years from Jan 1, 2007 to Sep 30, 2017. Bleeding was defined as hospitalization or emergency room visit with a primary diagnosis of gastrointestinal (GI) bleeding, intracranial hemorrhage (ICH), or bleeding at other sites. Risk of overall and by type of bleeding was examined in concomitant users of DOAC and DR compared to patients using DOAC alone after adjusting for covariates of interest and applying propensity score (PS) trimming via Cox proportional hazards modeling. Results: Among concomitant users of DR and A (1,932), D (3,117), and R (2,395), crude incidence rates of bleeding per 1,000 person-years were 17.2, 37.8, 61.8, respectively versus 26.8, 31.3, and 44.9 in users of A (51,420), D (42,312), and R (57,300) alone. Incidence rates stratified by PS showed higher bleeding incidence in concomitant users of DR with D or R, but not with A. No increased bleeding risk was associated with use of DR and A vs A alone [Adjusted Hazard ratio (aHR): 0.69 (95% CI: 0.40, 1.17), p=0.16]. A modestly increased risk of GI bleeding but not overall bleeding was associated with combined use of DR and D vs D alone [aHR bleeding: 1.18 (95% CI: 0.89, 1.56), p=0.26; aHR GI bleeding: 1.40 (95% CI: 1.01, 1.93); p=0.04]. An increased risk of overall bleeding, driven by GI bleeding, was associated with combined use of DR and R vs R alone [aHR bleeding:1.31 (95% CI: 1.01, 1.69); p=0.04; aHR GI bleeding:1.39 (95% CI: 0.98, 1.95); p=0.06]. There was no increase in the risk of ICH associated with combined use of DR and any DOAC. Conclusions: Concomitant treatment with DR and A showed no increased risk of bleeding, but DR increased the risk of GI bleeding when given with D or R, and of overall bleeding only with R. Concomitant treatment with DR and any DOAC did not increase ICH risk.