Thoracoscopic Versus Catheter Ablation in Persistent Atrial Fibrillation With Enlarged Left Atrium

Pulmonary vein isolation is an established rhythm-control therapy for symptomatic atrial fibrillation refractory to antiarrhythmic drugs. Its efficacy is lower in persistent than in paroxysmal atrial fibrillation, and additional substrate modification of the left atrium is frequently required.

Percutaneous catheter ablation (radiofrequency, cryoballoon or PFA) and thoracoscopic surgical ablation are both used in current practice. Thoracoscopic ablation additionally allows epicardial pulmonary vein isolation, ganglionated plexi ablation, dissection of the ligament of Marshall, and left atrial appendage exclusion, at the cost of a longer hospital stay and a higher incidence of post-procedural pericarditis. Recent trials have shown broadly comparable efficacy and safety between the two approaches, so both are used interchangeably in practice.

In a retrospective analysis of the institutional ablation registry at the study site, overall outcomes of the two strategies were comparable, but among patients with an enlarged left atrium thoracoscopic ablation was associated with significantly lower recurrence of atrial tachyarrhythmia. Because that finding came from a subgroup of a retrospective cohort, it could not support a firm conclusion.

This trial therefore prospectively tests, in patients with persistent atrial fibrillation and an enlarged left atrium undergoing a first rhythm-control procedure, whether thoracoscopic ablation is superior to percutaneous catheter ablation.

Post-procedural management is identical in both arms: a 3-month blanking period, discontinuation of antiarrhythmic drugs at 3 months (up to 6 months) if sinus rhythm is maintained, and anticoagulation for at least 3 months with subsequent decisions based on recurrence, prior stroke, and CHA2DS2-VASc score. Follow-up visits occur at 3, 6, and 12 months and every 6 months thereafter until 1 year after the last patient is enrolled. Rhythm monitoring uses 12-lead ECG, 24-hour Holter (3, 6, 12 months), and 14-day patch monitoring; echocardiography and NT-proBNP are obtained at baseline, 12 months, and annually thereafter.

Inclusion criteria

• Age 19 years or older
• Persistent atrial fibrillation refractory to antiarrhythmic drug therapy, or in whom antiarrhythmic drug therapy cannot be maintained
• European Heart Rhythm Association (EHRA) symptom score ≥ 2
• Considered suitable for rhythm-control therapy by either percutaneous catheter ablation or thoracoscopic ablation, at the investigator's medical discretion
• Enlarged left atrium, defined as left atrial diameter ≥ 50 mm or left atrial volume index ≥ 45 mL/m²

Exclusion criteria

• Previous percutaneous catheter ablation or thoracoscopic ablation for atrial fibrillation
• Previous thoracic or cardiac surgery
• Absolute contraindication to anticoagulation therapy
• Life expectancy less than 1 year due to non-cardiac disease, or anticipated poor adherence to treatment, at the investigator's medical discretion
• Refusal to participate in the study