Effects of Dronedarone on Cardiac Geometry and Function in Patients With Atrial Fibrillation and Left Atrial Enlargement

Inclusion criteria: * Signed written informed consent and Health Insurance Portability and Accountability Act (HIPAA) Authorization; * Nonpermanent AF or AF/Atrial Flutter (AFL) documented electrocardiographically by both AF (or AF/AFL) and sinus rhythm within the prior 12 months; * At screening, sinus rhythm and Left Atrial Volume index (LAVi) ≥32 mL/m2 based on 2D-echocardiography; * At least one of the following cardiovascular (CV) risk factors: Age \>70 years at start of screening, hypertension, diabetes mellitus, prior CV accident (stroke or transient ischemic attack) or systemic embolism, or left ventricular ejection fraction \<0.40. Exclusion criteria: * Permanent AF defined as continuous AF for 6 months or longer; * Persistent AF defined as sustained AF \>7 days duration and/or requiring cardioversion in the 4 weeks before screening; * Prior valvular heart surgery or significant valvular heart disease including rheumatic heart disease or acquired valvular heart disease; * Aortic or mitral regurgitation greater than mild (\>1+) or any degree of mitral stenosis at the screening echocardiogram; * Myocardial infarction within the 6 months prior to screening or stroke within 2 months prior to screening; * Pacemaker, implantable cardioverter defibrillator, or cardiac resynchronization therapy devices placed within the 6 months prior to screening or at anytime during the study; * Ongoing potentially dangerous symptoms when in AF/AFL such as angina pectoris, transient ischemic attacks, stroke, syncope as judged by the Investigator; * Cardiac ablative procedure or cardiac surgery within 3 months prior to screening, or percutaneous coronary intervention within 4 weeks prior to screening; * Need for concomitant medication that is prohibited in this trial, and would preclude the use of the study drug during the planned study period including the following: * Antiarrhythmics (eg, amiodarone, flecainide, propafenone, quinidine, disopyramide, dofetilide, sotalol); * Drugs or products that are strong inhibitors of CYP3A (eg, ketoconazole, itraconazole, voriconazole, cyclosporine, telithromycin, clarithromycin, nefazodone, ritonavir, and grapefruit juice); * Drugs that are inducers of CYP3A (eg, rifampin, phenobarbital, carbamazepine, phenytoin, and St John's wort); * QTc Bazett interval ≥500 msec on the screening ECG; * Bradycardia \<50 bpm and/or PR interval ≥0.28 sec on the screening ECG unless the patient has a functional pacemaker; * New York Heart Association (NYHA) Class IV heart failure or NYHA Class II or III heart failure with a recent decompensation requiring hospitalization or referral to a specialized heart failure clinic within 4 weeks prior to screening. The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.