Clinical findings from a large endo-epicardial atrial arrhythmia ablation registry

Abstract Background Despite advances, catheter ablation success rates for persistent AF remain at 50-60%. The approach for recurrent persistent AF, beyond pulmonary vein isolation, remains contentious. Surgical maze procedures have demonstrated superior outcomes compared to catheter ablation. Catheter-based linear lesions sets have failed to demonstrate efficacy, perhaps due to a lack of consistent transmurality with endocardial radiofrequency. Objective We report our safety and clinical data of an endo-epicardial approach using high-power radiofrequency ablation for atrial arrhythmias. Methods 126 patients (80% male; mean age 65 years [43-81]) underwent redo ablation, between August 2020 and February 2024, for recurrent symptomatic atrial arrhythmias using an endo-epicardial approach. We used a standardised linear lesion set (posterior wall isolation and anterior mitral line) for recurrent persistent AF. Results Utilising an intentional coronary sinus exit and C02 insufflation technique, we achieved epicardial access in 121 anti-coagulated patients. 5 patients were found to have pericardial adhesions, prohibiting access. There were 2 LIMA punctures which were coiled, 2 cases of excess pericardial bleeding (not access related), that settled conservatively, and no surgery or death. 92% of patients received epicardial ablation. 86 anterior mitral lines (95% acute block, 79% with epi ablation), 88 roof lines (92% blocked, 50% with epi ablation) and 81 floor lines (98% blocked, 36% with epi ablation) were undertaken. 106 posterior wall isolations were performed (94% isolated, 51% epi ablation). 75 patients had a standardised lesion set and were included for recurrence analysis. 49 had persistent AF (71% male, mean age 65 years, mean LAVI 38 ml/m2, 26 PVI at baseline and 23 PV reconnections) and 26 longstanding persistent AF (92% male, median age 64 years, mean LAVI 37.1 mls/m2, 16 PVI at baseline and 10 PV reconnections). 82% with persistent AF (median follow up time 11 months) and 38% with longstanding persistent AF (median follow up time 10.1 months) maintained sinus rhythm. The submitted image demonstrates the freedom from persistent AF, for the cohort who are beyond the 3-month blanking period, as per classification of atrial arrhythmia. Conclusion In one the largest cohorts to date, we have shown that endo-epicardial atrial ablation is feasible and safe with epicardial ablation allowing improved transmurality and thus acute linear block. Clinical outcomes, using a posterior wall isolation and anterior mitral line, were favourable for persistent but not longstanding persistent AF.