Long-Term Outcomes of Cardioneuroablation with and without Extra-Cardiac Vagal Stimulation Confirmation in Severe Cardioinhibitory Neurocardiogenic Syncope

Background Cardioneuroablation (CNA) is a novel therapeutic approach for functional bradyarrhythmias, specifically neurocardiogenic syncope or atrial fibrillation, achieved through endocardial radiofrequency catheter ablation of vagal innervation, obviating the need for pacemaker implantation. Originating in the nineties, the first series of CNA procedures was published in 2005. Extra-cardiac vagal stimulation (ECVS) is employed as a direct method for stepwise denervation control during CNA. Objective This study aimed to compare the long-term follow-up outcomes of patients with severe cardioinhibitory syncope undergoing CNA with and without denervation confirmation via ECVS. Method A cohort of 48 patients, predominantly female (56.3%), suffering from recurrent syncope (5.1±2.5 episodes annually) that remained unresponsive to clinical and pharmacological interventions, underwent CNA, divided into two groups: ECVS and NoECVS, consisting of 34 and 14 cases, respectively. ECVS procedures were conducted with and without atrial pacing. Results Demographic characteristics, left atrial size, and ejection fraction displayed no statistically significant differences between the groups. Follow-up duration was comparable, with 29.1 ± 15 months for the ECVS group and 31.9±20 months for the NoECVS group (p=0.24). Notably, syncope recurrence was significantly lower in the ECVS group (2 cases vs. 4 cases, Log Rank p=0.04). Moreover, the Hazard ratio revealed a five-fold higher risk of syncope recurrence in the NoECVS group. Conclusion This study demonstrates that concluding CNA with denervation confirmation via ECVS yields a higher success rate and a substantially reduced risk of syncope recurrence compared to procedures without ECVS confirmation.