Safety of Dronedarone in Routine Clinical Care

Objectives The aim of this study was to examine mortality and liver disease among patients exposed to dronedarone. Background There has been concern about the safety of dronedarone, especially for patients with heart failure and permanent atrial fibrillation (AF). There have also been suspicions about liver toxicity. Methods All 174,995 patients with a diagnosis of AF during 2010 to 2012 were identified in the Swedish Patient Register. Of these, 4,856 patients had received dronedarone according to the Swedish Drug Register, and 170,139 patients who had not were used as a control population. Mean follow-up was 1.6 years, with a minimal follow-up of 6 months. Results Patients prescribed dronedarone were younger (age 65.5 years vs. 75.7 years, p < 0.0001) and healthier than control patients. The annual mortality rate among patients who received dronedarone was 1.3% compared with 14.0% in the control population. There were no sudden cardiac deaths and no deaths related to liver failure among patients who received treatment with dronedarone. After propensity score matching and adjustment for cofactors, patients who received dronedarone had lower mortality than other AF patients (hazard ratio [HR]: 0.41; 95% confidence interval [CI]: 0.33 to 0.51). Dronedarone patients with heart failure had lower mortality than other heart failure patients (HR: 0.40; 95% CI: 0.30 to 0.53). They also had lower mortality than expected from the general population (standardized mortality ratio: 0.67; 95% CI: 0.55 to 0.78), which indicates the selection of low-risk patients. The risk of liver disease was not increased (HR: 0.57; 95% CI: 0.34 to 0.92). Conclusions Dronedarone, as prescribed to AF patients in Sweden, has not exposed patients to increased risks of death or liver disease. (C) 2014 by the American College of Cardiology Foundation