Matched cohort comparison between endo epicardial and lattice tip catheter ablation for non paroxysmal atrial fibrillation utilising a standardised left atrial lesion set

Background Despite recent advances, catheter ablation for persistent atrial fibrillation remains limited in efficacy. Catheter-based linear lesion sets have not consistently shown benefit, largely owing to insufficient transmurality with endocardial radiofrequency. An endo-epicardial ablation strategy has been associated with higher acute block rates, and the lattice-tip catheter has reported to achieve greater lesion depth and more durable endocardial linear block. Objective An age, sex, and AF classification–matched retrospective cohort treated with endo–epicardial ablation was compared with a prospective series undergoing lattice-tip catheter ablation for non-paroxysmal atrial fibrillation. Methods Between January 2021 and April 2024, 24 patients with non-paroxysmal AF (75% male; mean age 71 years [56–78]; 21% longstanding persistent; median LA volume 91 mls) underwent an endo–epicardial ablation. Outcomes were compared with a matched cohort of 24 patients (75% male; mean age 71 years [55–85]; 21% longstanding persistent; median LA volume 97 mls) who underwent a lattice-tip catheter ablation for non-paroxysmal AF between April and October 2025. All procedures used a standardised left atrial lesion set comprising pulmonary vein isolation, posterior wall isolation, and anterior mitral line, with optional cavotricuspid isthmus ablation. Results Epicardial access using the EpiCO2 technique was achieved in 24 anticoagulated endo–epicardial cases without complications; lesion sets comprised an anterior mitral line (100% acute block, 92% with epi ablation), a roof line (100% acute block, 75% with epi ablation), a floor line (96% acute block, 33% with epi ablation), and four cavotricuspid isthmus lines (100% acute block). In the lattice-tip cohort, procedures included an anterior mitral line (100% acute block, 67% dual energy), an anterior roof line (100% acute block, 38% dual energy), a floor line (100% acute block, 100% pulsed-field ablation), and 17 cavotricuspid isthmus lines (100% acute block, 65% dual energy), with no complications observed. During the blanking period, there were four atrial arrhythmia recurrences in the lattice-tip cohort (50% atrial tachycardia) and seven in the endo–epicardial cohort (14% atrial tachycardia). 83% remained free from persistent AF/AT after 12 months (21% ILR, 58% TTM, 21% 3 monthly holters) in the endo-epicardial cohort. The median 10 month follow up data for the lattice-tip cohort will be presented at the congress (96% 3 monthly holters, 4% ILR). Conclusion In this matched comparative study, endo–epicardial and lattice-tip ablation achieved similarly high rates of acute block with comparable safety. The high acute block rate in the endo–epicardial cohort may account for the observed freedom from atrial arrhythmia recurrence. Additional follow-up in the lattice-tip cohort is required to determine whether its acute block rates translate into comparable long-term freedom from atrial arrhythmias.