Biatrial catheter ablation for persistent atrial fibrillation: Prospective registry-based observational study

BACKGROUND Biatrial surgical ablation has demonstrated superior rhythm outcomes compared with left atrial ablation alone, but is associated with an increased risk of sinus node dysfunction and subsequent pacemaker implantation in patients with atrial fibrillation (AF). OBJECTIVE To evaluate the feasibility of right atrial (RA) linear ablation with bidirectional conduction block and the incidence of pacemaker implantation for sinus node dysfunction. METHODS This prospective, single-center cohort study was conducted between 2022 and 2023. Eligible patients had persistent AF and were scheduled for an initial catheter ablation procedure. RA linear ablation, comprising superior vena cava isolation, intercaval linear ablation, and cavotricuspid isthmus ablation, was performed in addition to pulmonary vein isolation (PVI). The primary efficacy endpoint was successful completion of RA linear ablation. The primary safety endpoint was pacemaker implantation for sick sinus syndrome within 1 month after the procedure. RESULTS 97 patients (median age, 63.0 [IQR: 55.0, 70.0 years]; 17 females [17.5%]) underwent RA linear ablation. Complete RA linear ablation with bidirectional block was achieved in 91 patients (94%). The one-sided lower 97.5% confidence limit was 87%, exceeding the prespecified performance goal of 70% (p <0.001). No patients required permanent pacemaker implantation, which was significantly below the prespecified goal of 7% (p <0.001). Freedom from atrial tachyarrhythmia at 1 year was 82.4%. CONCLUSION RA linear ablation with verified bidirectional block was feasible and safe, with no permanent pacemaker implantation within 1 month; its incremental efficacy requires randomized evaluation with intensive monitoring.