22-03: Thoracoscopic Ganglionic Plexus Ablation does not Improve Outcome in Advanced Atrial Fibrillation. The AFACT trial

Abstract

Introduction: Patients with long atrial fibrillation (AF) duration, enlarged left atria (LA) or previously failed ablation, have advanced AF and may require more extensive treatment than pulmonary vein isolation (PVI) alone. AFACT (NCT01091389) investigated efficacy and safety of additional ganglionic plexus (GP) ablation in patients undergoing thoracoscopic surgery for advanced AF during one year of follow-up. Method(s): Patients were subjected to PVI ( paroxysmal AF) or PVI plus a roof and trigone line (Dallas lesion set, persistent AF), and randomized 1:1 to GP ablation (GP group) or no GP ablation. In the GP group, 4 major GPs and the ligament of Marshall were ablated epicardially. Follow up was performed with ECGs and 24-hour Holters every 3 months for 1 year, with additional symptom driven ECGs. After a 3-month blanking period, all antiarrhythmic drugs (AAD) were discontinued in all patients. Any atrial arrhythmia lasting .30 seconds after the blanking period defined recurrence. Result(s): We included 240 patients (age 60 + 8 years, 73% men, AF duration 5.7 + 5.1 (1-35) years, 59% persistent). LA volume was 40 and 41 ml/m2 in the GP (n = 117) and control group (n = 123) respectively. Procedure time was 185 + 54 and 168 + 54 minutes (p = 0.015), and GP ablation eliminated 100% of evoked vagal responses (a vagal response remained in 87% of control patients). Major bleedings occurred in 9 patients, all in the GP group (p , 0.001). Eight bleedings were managed thoracoscopically, 1 patient underwent a sternotomy. After one year, 4 patients had died (all in the GP group, not procedure related p = 0.055) and 9 were lost to followup. Freedom of AF recurrence was 80 vs 74.5% (p = 0.6) in paroxysmal and 65.7 vs 62.9% (p = 0.9) in persistent AF; in the GP and control group after a single procedure. During the blanking period AF recurred in 34.5 and 29.3% patients, cardioversion was performed in 25 and 28 patients. Cardioversions were performed in 22 vs 21 patients after the blanking period, respectively. Recurrences constituted more atrial tachycardia in the GP group (78.1 vs 51.4%) and more AF in the control group (48.6 vs 21.9%, p = 0.026). Clinically relevant sinus node dysfunction occurred in 12 GP and 4 control patients (p = 0.038), necessitating 3 pacemaker implantations during admission and 3 during follow up, all in the GP group (5%, p = 0.013). Conclusion(s): AFACT, the largest randomized study in thoracoscopic surgery for advanced AF to date, demonstrates that GP ablation is associated with significantly more periprocedural major bleeding, sinus node dysfunction, and pacemaker implantation, but not with improved rhythm outcome. Routine GP ablation offers no clinical benefit and should not be performed in this patient category.