Efficacy and safety of dronedarone in patients previously treated with other antiarrhythmic agents

Abstract

Background: Currently available antiarrhythmic drugs (AADs) for the prevention of atrial fibrillation (AF)/atrial flutter (AFL) suffer from incomplete efficacy and poor tolerability. Hypothesis: Dronedarone could represent an effective and safe option in patients previously treated with AADs, especially class Ic AADs and sotalol. Methods: Retrospective analysis of 2 double-blind, parallel-group trials (EURIDIS [European Trial in Atrial Fibrillation or Flutter Patients Receiving Dronedarone for the Maintenance of Sinus Rhythm] and ADONIS [American-Australian-African Trial With Dronedarone in Atrial Fibrillation or Flutter Patients for the Maintenance of Sinus Rhythm]) comparing the efficacy and safety of dronedarone with placebo over 12 months. The primary end point was AF/AFL recurrence in patients previously treated with another AAD that was discontinued for whatever reason prior to randomization. Results: In patients previously treated with any AADs, dronedarone decreased the risk of AF recurrence by 30.4% vs placebo (hazard ratio [HR]: 0.70; 95% confidence interval [CI]: 0.59-0.82; P < 0.001). In patients previously treated with a class Ic agent, dronedarone decreased the risk of recurrence by 31.4% (HR: 0.69; 95% CI: 0.53-0.89; P = 0.004), whereas in patients previously treated with sotalol, dronedarone showed a trend toward a decrease of risk of recurrence (HR: 0.86; 95% CI: 0.67-1.11; P = 0.244). Dronedarone was equally effective irrespective of whether class Ic or sotalol were stopped for lack of efficacy or adverse events (AEs). Discontinuation rates were similar in the 2 groups (55.9% vs 43.1%), as were incidence of AEs and serious AEs. Conclusions: Dronedarone seems to be effective in preventing AF recurrences in patients without permanent AF previously treated with other AADs, even if those were discontinued for lack of efficacy. Dronedarone appears to be well tolerated even in patients who already had tolerability issues with AADs.