Comparative outcomes of amiodarone and dronedarone in atrial fibrillation: a real-world retrospective cohort study
A Akuka, T Stahi, M Geist, U Nussunovitch, G Zacay, R Rubinshtien, H SteinerAbstract
Background
Atrial fibrillation is the most prevalent sustained arrhythmia, and antiarrhythmic drugs remain the cornerstone of management. Amiodarone is recognized for its high efficacy, however, its utility is significantly curtailed by side effects. While dronedarone has an improved safety profile, it has lesser antiarrhythmic efficacy. Both drugs are among the few options for rhythm control in patients with structural heart disease. Comparisons between treatments with these agents is limited.
Purpose
This study sought to evaluate the long-term comparative outcomes with amiodarone versus dronedarone for atrial fibrillation in a real-world cohort of patients.
Methods
We conducted a retrospective cohort study using comprehensive data from national health maintenance organization including all adult patients initiating amiodarone or dronedarone for atrial fibrillation management between 2014 and 2021. The primary outcome was defined as all-cause mortality. Secondary outcomes included a composite of cardiovascular hospitalizations, hospitalization due to bradyarrhythmia, need for electrical cardioversion, pacemaker implantation, and incidence of ventricular arrhythmias.
Results
The final cohort comprised 4739 patients initiating amiodarone and 192 patients with dronedarone. The amiodarone group exhibited a significantly higher rate of prior heart failure (30.0% vs. 20.8%, p=0.008). Other baseline characteristics and risk factors were comparable between the groups. Regarding the study outcomes, the crude all-cause mortality rate was significantly higher in the amiodarone group compared to the dronedarone group (18% vs. 2.6%, p<0.001). The mean duration in days of drug adherence was also significantly lower in the amiodarone group (557.6 ±679.4 vs. 693.4 ±719.9, p=0.011). Multivariate Cox regression analysis showed that amiodarone use remained independently associated with significantly lower all-cause mortality compared to dronedarone (HR 6.98, CI 2.89-16.84, p<0.001). No significant differences were observed between the two treatment groups for the secondary outcomes, including rates of cardiovascular hospitalization, hospitalization due to atrial fibrillation, and episodes of ventricular arrhythmias.
Conclusion
In this large, real-world cohort of patients, dronedarone was associated with superior long-term survival and better therapeutic adherence compared to amiodarone, without increasing the risk of cardiovascular or atrial fibrillation hospitalization or the need for cardioversion. These findings suggest that dronedarone should be considered as the preferred initial antiarrhythmic drug in this challenging patient population.Table 1:Baseline characteristics and ouTable 2:Multivariate cox regression ana