Clinical Research Directory

Inclusion Criteria: * Persistent or long-standing persistent AF proved on at least two 12-lead ECG recordings more than one week apart or \> 7-day EKG Holter recordings * Age ≥ 18 years at the time of study enrollment * Signed informed consent Exclusion Criteria: * Paroxysmal AF * Sinus rhythm on the 12-lead ECG on admission unless recent external electrical cardioversion was carried out within the last six months and the patient is treated by amiodarone * LA diameter \> 55 mm (measured in the parasternal long-axis view) * History of AF ablation in the past * History of cardiac surgery * Significant valvular defect * Age below 18 years * Pregnancy, breastfeeding * Any disease with a life expectancy \<1 year * Terminal renal failure * History of pacemaker or defibrillator implantation * Significant thyroid disease * Uncorrected congenital heart disease or valvular obstruction * Obstructive hypertrophic cardiomyopathy * Active myocarditis * Constrictive pericarditis * Untreated hypothyroidism or hyperthyroidism * Adrenal insufficiency * Active vasculitis due to collagen vascular disease * Presence on a heart transplant waiting list (UNOS category 1A or 1B or equivalent). Patients on a non-acute heart transplant waiting list (UNOS category 2 or 7 or equal) are eligible for inclusion in the study * Recipient of any major organ transplant (e.g., lung, liver, heart) * Patient who is undergoing or has undergone cytotoxic or cytostatic chemotherapy and radiation therapy for the treatment of malignancy within six months before randomization or clinical evidence of current malignancy, with the following exceptions: basal or squamous cell carcinoma of the skin, cervical intraepithelial neoplasia, prostate cancer (if the localized disease is stable, with life expectancy \> 2.5 years in the opinion of the investigator) * HIV positivity with a survival expectancy of less than five years due to HIV * Chronic kidney disease with glomerular filtration rate \< 30 ml/min * Chronic dialysis treatment * Recent (within three months) self-reported history of alcoholism or illicit drug dependence * Any illness (e.g., psychiatric illness) or situation that, in the opinion of the investigator, could place the subject at significant risk, confound the results of the study, or significantly affect the subject's participation in the study * Unwillingness to participate.