Dronedarone Lowers All-Cause Mortality in Patients with AFib

SAN FRANCISCO, CA—Dronedarone use resulted in lower all-cause mortality compared with other antiarrhythmic drugs with no increased risk of cardiovascular-related deaths/ hospitalizations observed in patients with atrial fibrillation (AFib), as presented at ACC.13, the American College of Cardiology's 62nd Annual Scientific Session.

Dronedarone is the latest antiarrhythmic drug approved to reduce the risk of hospitalization for AFib in patients in sinus rhythm with a history of paroxysmal or persistent AFib.

Earl Goehring, from The Degge Group, Ltd., Arlington, VA, and study team conducted a retrospective cohort study to evaluate cardiovascular outcomes associated with dronedarone use compared to more established atrial fibrillation treatments in a “real-world” setting. The study's assessment of health outcomes and associated risk factors included: all-cause mortality, cardiovascular hospitalizations and/or death from any cause, inpatient hospitalization of >1 night, cardioversion, hospitalization for AFib or atrial flutter recurrence, and inpatient hospitalization of >1 night for cardioversion, transient ischemic attack, cerebrovascular accident, heart failure, and/or bleeding.

Data was extracted from the United States Department of Defense Electronic Health Record database from July 20,2009–July 19, 2011. Based on the patient's first prescription, they were allocated to one of four cohorts: dronedarone, calcium channel blockers (eg, nifedipine, verapamil, nicardipine, diltiazem, isradipine, nimodipine, amlodipine, felodipine, nisoldipine, or bepdril), “other antiarrhythmic drugs” (Class Ic/III: amiodarone, adenosine, disopyramide, dofetilide, flecainide, lidocaine, mexilitine, quinidine, phenytoin, procainamide, propafenone, ranolazine, or sotalol), or digoxin.  This sub-analysis only focused on patients that were new initiators of dronedarone and “other antiarrhythmic drugs”.

In total, 41, 178 patients were identified and included in the study population (n=3,020 dronedarone users and n=38,158 “other antiarrhythmic drugs” users). Propensity-score matching resulted in 2,079 baseline dronedarone patients and 4,158 other antiarrhythmic patients with similar baseline characteristics.  This sub-analysis showed that all-cause mortality was higher in the other antiarrhythmics patients compared with the dronedarone initiators (0.7% vs. 0.3%, respectively; hazard ratio 2.28; confidence interval [CI] 1.00–5.20, P<0.05).

There were no significant differences in cardiovascular hospitalizations (8.4% vs. 7.8%, respectively; hazard ratio 1.16; CI 0.96–1.40, P=0.117) or non-cardiovascular hospitalizations (14.6% vs. 13.8%, respectively; hazard ratio 1.11; CI 0.96–1.28; P=0.15].

Dronedarone use resulted in lower all-cause mortality compared with “other antiarrhythmics,” concluded Dr. Goehring and team. He added, “Notably, the benefit observed on cardiovascular hospitalizations and/or death was not offset by an increased risk of hospitalization for heart failure between dronedarone and other antiarrhythmics."