Limited data are available on the impact of dronedarone treatment in Asian patients with atrial fibrillation (AF) or atrial flutter (AFL). This post hoc analysis evaluated the efficacy and safety of dronedarone compared with placebo in populations from Asian and non-Asian regions randomized in the ATHENA trial (A Placebo-Controlled, Double-blind, Parallel Arm Trial to Assess the Efficacy of Dronedarone 400 mg BID for the Prevention of CV Hospitalization or Death From Any Cause in Patients With AF/AFL).Time to first hospitalization for cardiovascular events or death from any cause (primary outcome) and time to first AF/AFL event recurrence (secondary outcome) were analyzed by Kaplan-Meier curves and Cox proportional hazards regression.The risk of experiencing the primary composite outcome was significantly lower in the dronedarone-treated patients in both the Asian (hazard ratio = 0.541; 95% CI, 0.320-0.914]) and non-Asian (hazard ratio = 0.768; 95% CI, 0.696-0.848) populations than in the placebo-treated patients. The median time to the first AF/AFL event recurrence was longer in the dronedarone-treated population than in the placebo-treated populations: 183 vs 92 days (P = 0.165) in the Asian population and 534 vs 196 days (P < 0.001) in the non-Asian population. Treatment-emergent adverse events in Asian (81.2% vs 78.4%) and non-Asian (71.4% vs 68.7%) populations and serious treatment-emergent adverse events in Asian (14.3% vs 15.7%) and non-Asian (20.3% vs 21.5%) patients were comparable in patients taking dronedarone compared with those taking placebo.Efficacy and tolerability of dronedarone were consistent in the Asian population compared with the non-Asian population in the ATHENA trial. These finding may aid Asian health care professionals to select the appropriate first-line treatment for Asian patients with AF/AFL.Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.