Comparative outcomes of biatrial and left atrial endo epicardial lesion sets in longstanding persistent atrial fibrillation

Background Management of long-standing persistent atrial fibrillation remains unclear and despite multiple procedures success rates remain approximately 45%. Surgical strategies, such as the Cox-Maze IV procedure, have shown improved efficacy in this population; however, these gains are accompanied by higher complication rates and longer hospital stays. Objective Safety and clinical outcomes of an endo–epicardial strategy were evaluated by comparing a left-atrial only lesion set; pulmonary vein isolation, posterior wall isolation, and an anterior mitral line, with a bi-atrial lesion set comprising pulmonary vein isolation, posterior wall isolation, anterior mitral line, intercaval line, and cavotricuspid isthmus line, utilising high-power radiofrequency ablation in longstanding persistent AF patients presenting with recurrent atrial arrhythmias. Methods Between January 2024 and March 2025, 20 patients with recurrent atrial fibrillation underwent redo ablation using a bi-atrial endo–epicardial approach (70% male; mean age 67 years [50–77]; median AF duration 22 months; median left atrial volume 88 mL [45–114]). This was compared with 20 patients who underwent redo ablation using a left-atrial endo–epicardial approach between October 2020 and June 2024 (85% male; mean age 61 years [47–78]; median AF duration 19 months; median left atrial volume 65 mL [48–114]). Results Using an intentional coronary sinus exit with CO2 insufflation, epicardial access was achieved in all 40 anticoagulated patients. No complications occurred in the left-atrial cohort; in the bi-atrial cohort, one transient ischaemic attack (<1 hour) and two elective pacemaker were implanted seven months post-ablation for pre-existing sinus node disease. The bi-atrial cohort included roof lines (100% acute block; 85% with epicardial ablation), inferior line (95% acute block; 40% epicardial), anterior mitral lines (95% acute block; 75% epicardial), CTI lines (100% acute block), SVC isolation (100% acute block), and an intercaval line (100% acute block). In the left-atrial cohort, roof lines (90% acute block; 65% epicardial), the floor line (95% acute block; 20% epicardial), and the anterior mitral line (85% acute block; 75% epicardial). At 12 months, the bi-atrial cohort (median follow-up 609 days; monitoring: 75% implantable loop recorder, 25% Holter) demonstrated 85% freedom from persistent atrial arrhythmias, whereas the left-atrial cohort (median follow-up 1,348 days; monitoring: 15% implantable loop recorder, 45% transtelephonic monitoring, 35% Holter) demonstrated 60% freedom; favoring the bi-atrial strategy but this did not reach statistical significance (p=0.081). Conclusion Endo–epicardial atrial ablation appears feasible, promoting greater higher rates of acute linear block. A bi-atrial strategy may be promising for longstanding persistent atrial fibrillation; definitive assessment of clinical benefit requires evaluation in a randomised controlled trial.