Physiological Markers of Effective Autonomic Denervation Are Associated With Outcomes After Cardioneuroablation for Vasovagal Syncope

BACKGROUND: Cardioneuroablation (CNA) has been increasingly pursued as a treatment for patients with recurrent vasovagal syncope. The optimal procedural approach and acute endpoints are unclear. OBJECTIVE: The goal of this study was to characterize procedural markers linked to durable freedom from syncope. METHODS: All patients who underwent CNA for vasovagal syncope refractory to lifestyle modification with at least 1 year of follow-up were included in a retrospective cohort. Clinical and procedural characteristics were analyzed for association with recurrence of syncope. RESULTS: A total of 57 patients (mean age 39.8 ± 10.7 years; 53% female; 6.7 ± 3.8 episodes of syncope in the prior year) met inclusion criteria. During 2.2 ± 0.8 years of follow-up, 25 patients (44%) had recurrent syncope. Symptomatic inappropriate sinus tachycardia occurred in 14% and was more common after CNA guided by extracardiac vagal stimulation (64% vs 2%). Patients who remained free from recurrent syncope were more likely to exhibit a vagal response during ablation of the left-sided ganglionated plexus (56% vs 12%; P = 0.001), had a greater increase in sinus rate during the ablation (29.9 ± 15.1 beats/min vs 10.0 ± 15.8 beats/min; P = 0.01), and were less likely to exhibit a positive atropine response at the end of the procedure (3% vs 24%; P = 0.04). Patients who exhibited a greater number of these favorable physiological markers had progressively lower rates of recurrent syncope. Patients meeting all 3 criteria had the lowest recurrence rate (14%). CONCLUSIONS: There is a substantial rate of recurrent syncope after CNA with intermediate-term follow-up. Inadequate acute procedural endpoints may be associated with recurrence.