Repeated ablation procedure in a persistent atrial fibrillation population. The Role of Vein of Marshall Ethanol Infusion combined with an anatomical ablation setup

Abstract Introduction Studies in literature show limited long-term efficacy of catheter ablation (CA) in persistent atrial fibrillation (PeAF) patients. Procedural strategy for repeated ablation is a great challenge especially in patients with already isolated pulmonary veins (PVs). Vein of Marshall ethanol infusion (VOM-EI) is a promising approach for PeAF, but its role in repeated ablations is poorly investigated. In this prospective observational study, we analysed PeAF patients undergoing repeat ablation with VOM-EI, eventual revision of PVI, linear lesions for left atrial (LA) dome, lateral mitral isthmus (MI) and cavo-tricuspid isthmus (CTI). We aimed to evaluate the outcome of this procedural setup based on the previous ablation strategy. Methods Thirty-nine PeAF patients were scheduled for repeated ablation, classified by AF duration into early PeAF (≤3 months), PeAF (3-12 months), and long-lasting PeAF (>12 months). Based on prior ablation, patients were grouped into PVI and PVI+ (PVs isolation only vs combined with linear lesions and/or CFAEs abolition). We applied a systematic anatomical ablation setup. After VOM-EI, PVI reconnections were targeted. During LA pacing, bidirectional block across prior ablation lines was assessed, with touch-up ablation performed if needed. Ablation of the LA dome, lateral MI, and CTI line were performed and validated. Antiarrhythmic drugs were discontinued after 1-month. AT/AF recurrences lasting >30 seconds represented the end-point. Kaplan-Meier analysis with Log Rank test and Cox regression analysis were performed to evaluate recurrence based on prior ablation setup and AFphenotype. Results Thirty-nine PeAF patients were analysed. According to the previous ablation setup 26/39 (67%) and 13/39 (33%) patients were PVI and PVI+, respectively. According with AF duration, 11 patients (27%) were early PeAF, while 10 (27%) and 18 (46%) PeAF and long-lasting PeAF, respectively. Mean follow up was 14.4±7.5 months. 8/39 patients (21%) had documented recurrence of AF/AT during the follow-up. Recurrences happened in 5/26 (19%) PVI patients and 3/13 (23%) PVI+ ones (p=0.76). At univariate analysis, PVs reconnection and long-standing AF were significant determinants of arrhythmic recurrences (p=0.05 and p=0.04, respectively). Interestingly, PVI reconnection, especially in the PVI group, was strongly associated with arrhythmias-free outcome (p=0.006). Conclusion Regardless of previous procedural setup, VOM-EI in addition to PVI and anatomical scheme validation represents a valid option at time of repeated ablation in PeAF patients. PVs reconnections happened frequently in our population. Patients with PVI reconnection demonstrated a better outcome with respect to those with PVI already obtained. Long-lasting PeAF patients had worse outcome.Precedural workflow and outcomes Patients' characteristics