Catheter ablation for recurrent atrial arrhythmias after surgical atrial fibrillation ablation: procedural characteristics, safety, and clinical outcomes

Background Surgical ablation procedures, such as the Cox-Maze operation and its modified variants, are established treatment options for atrial fibrillation (AF). Despite favorable success rates, a significant proportion of patients experience recurrent atrial arrhythmias (AA). The underlying mechanisms include incomplete lesion sets, atrial remodeling, or the emergence of novel arrhythmogenic substrates. In such cases, catheter ablation (CA) may serve as an effective therapeutic option. However, evidence regarding the efficacy, safety, and procedural characteristics of first CA after surgical ablation remains limited. Purpose To evaluate procedural characteristics, safety, and clinical outcomes of first CA in patients with recurrent AA after surgical AF ablation. Methods We retrospectively analyzed all patients undergoing first CA for recurrent AA after prior surgical AF ablation between June 2016 and September 2025 at a single tertiary care center. Procedural data, acute outcomes, and complications were collected. Freedom from AA was assessed during follow-up. Results A total of 40 patients (mean age 67±9 years, 14 (35 %) female) were included. Recurrence of AF was the predominant indication for CA (38 patients, 95%), although 23 patients (58%) had a history of atrial tachycardia (AT) after surgical ablation. Mean procedure time was 142 ± 46 minutes. Re-isolation of pulmonary veins (PV) was required in 34 patients (85%). Low-voltage areas (LVA) were observed in 20 patients (50%), necessitating additional ablation lines in the left atrium (LA). Cavotricuspid isthmus ablation (CTI) was performed in 14 patients (35%). AT was either present at baseline or inducible during the procedure in 18 patients (45%). One access-site complication (AV fistula, 3%) occurred. After a median follow-up of 11 months (IQR 5–12), 25 of 37 patients (68%) remained in sinus rhythm (SR). Conclusion CA for recurrent AA after surgical AF ablation is feasible and safe. PV reconnection was frequently observed and required re-isolation. Nevertheless, the frequent presence of atrial cardiomyopathy with extensive LVA and AT often necessitated additional substrate modification. More than two-thirds of patients (68%) remained in SR during follow-up, supporting CA as an effective therapeutic option in this complex patient population.