CARDIONEUROABLATION FOR FUNCTIONAL BRADYCARDIA AND VASOVAGAL SYNCOPE OUTCOMES FROM THE US MULTICENTER CNA REGISTRY.

Background: Cardioneuroablation (CNA) shows promise as a viable alternative to permanent cardiac pacing and pharmacotherapy for patients with symptomatic functional bradycardia and debilitating vasovagal syncope (VVS). The evidence supporting a potential therapeutic role of CNA is limited by relatively small sample sizes from predominantly single-center reports.

Objective: To report the feasibility, safety, and clinical efficacy of CNA from a large, first-ever multicenter US registry.

Methods: A multicenter registry from 15 US sites was established by collecting data from consecutive patients undergoing CNA for recurrent VVS or symptomatic functional bradycardia [sinus bradycardia (SB) or atrioventricular block (AVB)] refractory to medical therapy and behavioral modification (2018-2024).

Results: 205 patients that underwent 210 CNA procedures were included, the mean age was 47±17 years, 49% were female, and baseline LVEF was 60±5%. The most common indication for CNA was VVS syncope in 62%, followed by SB in 32%, AVB in 3%, or both SB and AVB in 2%. An anatomic approach to target typical ganglionated plexus (GP) locations was implemented in all cases, with high-frequency stimulation in 47% of procedures. Endocardial ablation targeting GPs was performed in both atria in 77%, with 697±515 seconds of radiofrequency application. Vagal and sympathetic responses during ablation were observed in 52% and 73% of cases, respectively. The mean increase in heart rate immediately after ablation was 20±15 bpm. Complications were observed in 4.7% of procedures: 2 respiratory failures requiring BiPAP, 1 right diaphragmatic paralysis, 4 sinus node dysfunction, with a major adverse event rate of 1.4% (2 hemopericardium, 1 death). At a mean follow-up of 14±11 months, 78% of patients with syncope remained free from recurrence, with a reduction in episodes from a median 7 (4-15) to median of 0 (0-0) episodes. 97% of the cohort remained free from pacemaker implantation.

Conclusions: In the largest multicenter CNA experience to date, acceleration of baseline heart rate and a significant reduction in syncope burden were achieved with an acceptable rate of major procedural complications. These observational data pave the way for future randomized trials to evolve CNA indications beyond compassionate usage for managing functional bradycardia and reflex syncope.