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

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.

Patients undergoing persistent AF ablation were included. Patients that had <30% low voltage zones (LVZs) in the left atrium underwent pulmonary vein isolation and GP ablation. Dominant frequency (DF), coronary sinus (CS) electrogram characteristics, and AF inducibility score were assessed pre- and post-GP ablation. Ganglionated plexi ablation response was determined. One hundred twenty 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 of ≥30 ms (33.3%)]. The average DF, CS cycle length variability (CLV), and CS activation pattern stability (APS) pre-GP ablation were predictive of AF termination. Ganglionated plexi ablation resulted in a significant change in the DF (6.3 ± 1.2 Hz pre-GP ablation vs. 5.1 ± 1.0 Hz; P < 0.001), CS CLV (40.2 ± 6.5 ms vs. 28.2 ± 6.8%; P < 0.001), and CS APS (25.2 ± 5.8% vs. 35.2 ± 6.5%; P < 0.001). Atrial fibrillation 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/atrial tachycardia (AT) off anti-arrhythmic drugs at 12-months.

Ganglionated plexi ablation results in a mechanistic impact in AF with an ablation response, changes in DF, CS electrogram characteristics, and AF inducibility score. Pulmonary vein isolation and GP ablation in patients with minimal LVZs results in a high freedom from AF/AT.