Efficacy and tolerability of dronedarone for patients with atrial fibrillation

Dronedarone is a new antiarrhythmic drug used in the treatment of atrial fibrillation (AF). We investigate its efficacy and tolerability in clinical practice.

We identified 208 patients treated with dronedarone for AF at the Northwestern outpatient practice. Charts were reviewed for clinical efficacy and reasons for discontinuation of the drug.

The average age was 65.2 ± 10.8 years, 37% females. Paroxysmal, persistent andpermanent AF were noted in 46.2%, 51.9%, and 1.9%, respectively. Average ejection fraction was 56.3 ± 9.1%, 12.8% had a history of congestive heart failure, and 10.3% had valvularheart disease. Dronedarone was discontinued in 25 patients after curative catheter or surgical ablation procedure. Of the remaining 183 patients, dronedarone was discontinued in 48.6% after a mean duration of 6.2 ± 6.3 months because of in efficacy (26.2%), side effects (6%), and other reasons (16.4%). For those remaining on dronedarone (n = 94), after a mean of 11.6 ± 6.6 months, clinical efficacy (resolution of or patient-reported improvement in symptoms) was noted in 45.4% patients. On dronedarone therapy, 57.4% had no AF on follow-up (overallefficacy of 29.5%). To evaluate efficacy, ECG only or long-term monitoring were performed in 62.7% and 37.3%, respectively, and found no AF in 69.2 and 48.4%, respectively. There were 3 deaths and 2 transient ischemic attacks (TIA) off dronedarone vs. 1 death, 1 TIA and 2 strokes on dronedarone.

Dronedarone has a significant discontinuation rate due to both inefficacy and side effects in clinical practice. Nevertheless, it has moderate clinical efficacy and tolerability in an outpatient population of patients with AF.