Ganglionated plexi ablation impact on AF mechanisms and outcomes in patients with low scar burden

Background and Aims Persistent atrial fibrillation (AF) ablation success rates remain limited. The aim was to evaluate the impact of ganglionated plexi (GP) ablation on AF mechanisms and outcomes in patients with low scar burden. Methods Patients undergoing persistent AF ablation were included. Patients that had <30% low voltage zones (LVZs) in the left atrium (LA) underwent pulmonary vein isolation (PVI) and GP ablation. Dominant frequency (DF), coronary sinus (CS) electrogram characteristics and AF inducibility score was assessed pre- and post-GP ablation. GP ablation response was determined. Results 120 patients were included of which 84 (70.0%) patients had <30% LVZs and underwent GP ablation. An ablation response was seen in all patients (AF termination (66.7%) and CL slowing ≥30ms (33.3%)). The average DF, CS cycle length variability (CLV) and CS activation pattern stability (APS) pre-GP ablation was predictive of AF termination. GP ablation resulted in a significant change in the DF (6.3±1.2Hz pre-GP ablation vs. 5.1±1.0Hz; p<0.001), CS CLV (40.2±6.5ms vs. 28.2±6.8%; p<0.001) and CS APS (25.2±5.8% vs. 35.2±6.5%; p<0.001). AF inducibility was harder post-GP ablation than pre-GP ablation (3.8±1.2 AF inducibility score pre-ablation vs. 1.3±1.8 AF inducibility score post-ablation; p<0.001). Seventy-eight out of the 84 (92.9%) patients were free from AF/AT off anti-arrhythmic drugs at 12-months. Conclusion GP ablation results in a mechanistic impact in AF with an ablation response, changes in DF, CS electrogram characteristics and AF inducibility score. PVI and GP ablation in patients with minimal LVZs results in a high freedom from AF/AT.