Optimal Timing of Dronedarone Initiation After Conversion in Patients With Persistent Atrial Fibrillation

Inclusion criteria: Screening: * Persistent AF for more than 72 hours (documented by an ECG taken within the last 72 hours) for whom cardioversion, anti-arrhythmic treatment and anticoagulation treatment are indicated in the opinion of the Investigator * Naive of amiodarone treatment in the last three months * QTc Bazett \< 500 ms on 12-lead ECG, * At least one cardiovascular risk factor (i.e. age \> 70, hypertension, diabetes, prior cerebrovascular disease or left atrial diameter \>= 50 mm Randomization: * Outpatient and Inpatients (except patients hospitalized during screening period for SAE) * Sinus rhythm * Effective oral anticoagulation verified by International Normalized Ratio/INR (target \> 2) * QTc Bazett \< 500 ms and PR \< 280 ms on 12-lead ECG * Completed treatment period with amiodarone (28 days ± 2 days) Exclusion criteria: Screening: * Contraindication to oral anticoagulation * Acute condition known to cause AF * Permanent AF * Paroxysmal AF * Bradycardia \< 50 bpm on the 12-lead ECG * Clinically overt congestive heart failure: * with New York Heart Association (NYHA) classes III and IV heart failure * with LVEF \< 35% * or NYHA class II with a recent decompensation requiring hospitalization or referral to a specialized heart failure clinic * or unstable hemodynamic conditions * Severe hepatic impairment * Previous treatment with class I or class III anti-arrhythmic drugs (including sotalol) if taken less than one week * Previous history of amiodarone intolerance or toxicity * Any contraindication as per dronedarone and amiodarone labelling * Wolff-Parkinson-White Syndrome * Previous ablation for atrial fibrillation or any planned ablation in the next 2 months * Contraindicated concomitant treatment: * Potent cytochrome P450 (CYP3A4) inhibitors * Use of drugs or herbal products that prolong the QT interval and known to increase the risk of Torsades de Pointes * Class I or III anti-arrhythmic drugs (including sotalol) Randomization: * Bradycardia \< 50 bpm on the 12-lead ECG * Clinically overt congestive heart failure: * with New York Heart Association (NYHA) classes III and IV heart failure * with LVEF \< 35% * or NYHA class II with a recent decompensation requiring hospitalization or referral to a specialized heart failure clinic * or unstable hemodynamic conditions * Severe hepatic impairment * Previous treatment with class I or class III anti-arrhythmic drugs (including sotalol) if taken less than one week * Patient in whom the following contraindicated concomitant treatment is mandatory: * Potent cytochrome P450 (CYP3A4) inhibitors * Use of drugs or herbal products that prolong the QT interval and known to increase the risk of Torsades de Pointes * Class I or III anti-arrhythmic drugs (including sotalol) The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.