Abstract 4144844: Comparison of Adjunctive Strategies Beyond Pulmonary Vein Isolation for Persistent Atrial Fibrillation: Cryoballoon-Based Left Atrial Modification vs. Posterior Left Atrial Box Isolation.

Background: To improve outcome of catheter ablation for persistent atrial fibrillation (AF), adjunctive strategies targeting non-pulmonary vein triggers and atrial substrate modification were pursued. Objectives: To investigate the efficacy of cryoballoon left atrial roof ablation as an adjunctive ablation for persistent AF. Methods: This retrospective study included 448 consecutive patients who underwent their first ablation procedure for persistent atrial fibrillation at Keio University Hospital from January 2016 to May 2023. Using propensity score matching, we extracted 79 pairs who underwent cryoballoon left atrial roof ablation (CB-RA) or BOX posterior wall isolation (BOX-PWI) using radiofrequency. We evaluated procedural characteristics and the recurrence incidence of atrial arrhythmia after a 90-day blanking period within one year. Results: In the matched cohort of 158 patients (median age 64 [58-70], 88% male, 30.4% with longstanding persistent AF), 25 patients (15.8%) experienced atrial arrhythmia relapse after the blanking period within one year. CB-RA was successfully completed in 55 patients (69.6%), and touch-up radiofrequency roof line ablation was required in 24 patients (30.4%). Additional bottom linear ablation was performed with cryoballoon or radiofrequency in 22 patients (27.8%) in the CB-RA group, based on the physician’s decision during the procedure. Freedom from atrial arrhythmia recurrence was comparable between groups over one year of follow-up (83.5% for CB-RA vs. 84.8% for BOX-PWI; hazard ratio (HR) 1.34, 95% confidence interval (CI) 0.61–2.94, P=0.48). Conclusion: In Japanese clinical practice, cryoballoon-based left atrial modification as an adjunctive therapy for persistent atrial fibrillation demonstrated acceptable outcomes comparable to those of posterior left atrial box isolation using radiofrequency.