Long-term recurrence-free survival following second-generation cryoballoon ablation for persistent atrial fibrillation: role of the autonomic nervous system

Abstract

Abstract Background The cardiac autonomic nervous system (ANS) plays a pivotal role in the regulation of atrial fibrillation (AF). Cryoballon (CB)-guided pulmonary vein isolation (PVI) is an established treatment for AF. Purpose In our present study we evaluated the impact of vagal reactions (VRs), as a surrogate parameter for ANS modulation, on the long-term outcome of CB-ablation in patients with persistent AF (PERS AF). Methods Data from consecutive PERS AF patients undergoing primary CB-guided PVI for symptomatic drug refractory AF between 2013-2023 were analysed. VRs were defined as bradycardia < 40 beats/min, asystole or higher-degree atrioventricular block. Long-term follow-up data were assessed. AF-recurrence was defined as AF lasting > 30 seconds beyond a 3-month blanking period. Results A total of 250 consecutive patients (mean age 63.9±10.0 years, 30% female) were included. VRs were recorded in 61 patients (24%, mean age 64.2±13.0 years, 30% female). The mean follow-up duration amounted to 84±14 months. Within this observation period 101 patients (40%) developed AF-recurrence. Re-ablation procedures were performed in 61 patients (60%). Patients with PVI-associated VRs presented with a significantly higher estimated AF-free survival rate (log-rank p-value < 0.001) (Figure 1) and a significantly longer median AF-free survival time (75 months, interquartile range (IR) 63-92 months) compared to those without (69 months, IR 13-79 months) (p=0.002). Beyond that Kaplan-Meier plot analyses revealed significant gender differences (Figure 1). Multivariate cox regression analyses confirmed VRs (Confidence interval (CI) 0.294-0.838, Hazard Ratio (HR) 0.497, p=0.009) and male gender (CI 0.352-0.781, HR, 524, p=0.001) as independent predictors (IPs) for AF-free-survival. Conclusion CB-ablation procedure associated VRs and male gender seem to be associated with a favorable long-term outcome in PERS AF. Further studies are warranted to verify our observations.Kaplan Meier plot on long-term AF-free s