Efficacy and Safety of Catheter abLation in patiEnts With seVere mitrAl regurgiTation and pErsistent Atrial Fibrillation: a Randomized Controlled Trial

Inclusion criteria

• Patients were required to have moderate-to-severe or greater (≥3+) atrial functional mitral regurgitation assessed by transthoracic echocardiography within 14 days before randomization. Mitral regurgitation severity was graded by an echocardiography core-lab based on the American Society of Echocardiography criteria, specifically an effective regurgitant orifice area (EROA) ≥30 mm²
• Age 18-80 years
• Persistent atrial fibrillation diagnosed by electrocardiogram
• Left ventricular ejection fraction ≥50% assessed by transthoracic echocardiography within 14 days before randomization(confirmed by the echocardiography core-lab)
• Left ventricular end-diastolic internal diameter ≤60 mm and left atrial anterior- posterior diameter ≤60 mm in echocardiographic parasternal long-axis view within 14 days before randomization(confirmed by the echocardiography core-lab)
• Agree to undergo catheter ablation and be able to undergo follow-up as required.

Exclusion criteria

• paroxysmal atrial fibrillation, atrial fibrillation secondary to an apparently reversible cause, or with history of previous ablation;
• primary mitral valve pathology, including calcification, sclerosis, prolapse, flail, tendon cable rupture, valve degeneration, infective endocarditis, rheumatic lesions, or ischemic lesions;
• history of previous mitral valve surgery or transcatheter manipulation;
• mitral valve orifice area \<4 cm2;
• aortic valve disease requiring surgical or transcatheter intervention;
• untreated clinically significant coronary artery disease requiring revascularization;
• history of previous myocardial infarction;
• previous definitive diagnosis of cardiomyopathies such as dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, constrictive pericarditis, arrhythmogenic cardiomyopathy, and infiltrative cardiomyopathies (e.g., amyloidosis, hemochromatosis, and nodular disease)
• echocardiographic evidence of intracardiac mass or thrombus;
• implant of cardiac device (pacemaker, implantable cardioverter defibrillator, cardiac resynchronization therapy device, or left atria appendage closure);
• hemodynamic instability requiring cardiac assist devices, intra-aortic balloon pump (IABP), or other hemodynamic support;
• any percutaneous cardiac intervention (percutaneous coronary intervention, transcatheter aortic valve replacement, etc.) within the 30 days prior to randomization,
• any cardiac surgery within the 6 months prior to randomization;
• active infections requiring current antibiotic therapy;
• a known hypersensitivity or contradiction to procedure medications which cannot be adequately managed medically;
• contraindication to appropriate anti-coagulation therapy;
• chronic obstructive pulmonary disease (COPD) requiring continuous home oxygen therapy or chronic oral steroid therapy;
• acute cerebrovascular accident within 30 days prior to randomization or Modified Rankin Score ≥ 4;
• symptomatic severe carotid stenosis (\>70% by ultrasound);
• other planned surgical or interventional procedures within the next 3 months;
• liver failure;
• renal failure or dialysis status;
• pregnant or planning pregnancy within the next 3 months;
• life expectancy \< 12 months (e.g., advanced malignant tumors);
• currently participating in other interventional studies;
• circumstances that, in the judgment of the researcher, make participation in this study unsuitable.