Characteristics and outcomes of patients undergoing extra-pulmonary vein ablation using pulsed field ablation for atrial fibrillation

PFA has been shown to be comparable to radiofrequency ablation and cryoablation in terms of acute safety and outcome for PVI for AF. Characteristics and outcomes of patients undergoing additional ablations beyond PVI using PFA (extra-PV ablation) such as posterior wall (PWA), cavotricuspid isthmus (CTI), mitral isthmus (MI) and superior vena cava (SVC) ablation are still under investigation. We hereby report the patient profile, procedural characteristics and 1-year outcomes for patients undergoing extra-PV PFA ablation.

Consecutive patients with paroxysmal or persistent atrial fibrillation who underwent PFA were included. The primary efficacy endpoint was any atrial arrhythmia recurrence after a 90-days blanking period at 1-year. Safety endpoints included all-cause death within 30 days, cardiac tamponade, CVA, myocardial infarction, PNI, AEF, PV stenosis, hemolysis and AKI.

200 (68% males) patients underwent PFA for AF, 45 (22.5%) were persistent and 16 (8.0%) had prior AF ablation. All patients had PVI. A total of 77 (38.5%) patients underwent extra-PV PFA ablation of which 66 (85.7%) underwent PWA only, 7 (9.1%) had both PWA + MI ablation and the remaining 4 patients each underwent either PWA + SVC ablation (n=1), PWA + CTI ablation (n=1), CTI + SVC ablation (n=1) or CTI + MI ablation (n=1). Extra-PV PFA ablations were more likely performed in patients with persistent AF, prior AF ablation, require GA, have lower mean LVEF and 100% EAM use (all p<0.001). While total PFA applications was expectedly higher in the extra-PV PFA group (63.8 ± 9.8 vs 46.0 ± 9.6, p<0.001), there were no significant differences in PFA LA dwell time (38.4 ± 11.8 vs 39.9 ± 15.6min, p=0.444), procedural time (116.3 ± 41.8 vs 121.6 ± 45.6min, p=0.402) and fluoroscopic time, (26.5 ± 8.0 vs 28.5 ± 11.8min, p=0.154). The average number of applications required for PWA, MI, CTI and SVC were 17, 11, 9 and 4 applications, respectively. Extra-PV isolation/ block was acutely successful in all 77 patients. Factors for performing PWA include presence of PW scar (21.6%), prior/ inducible LA tachycardia (16.2%), redo AF indication (13.5%), empiric in persistent AF patients (21.6%) and inadvertent narrow gap in the posterior wall (27.1%). There were no significant differences in all safety endpoints (all p>0.05). Arrhythmia recurrence occurred in 19 patients (9.9%), 11 (9.6%) in PVI only and 8 (10.5%) in extra-PV group (p=0.811). Use of AAD at follow-up was not significantly different (p = 0.143).

Extra-PV PFA ablation appears to be feasible and safe with excellent acute isolation and does not lengthen procedural nor fluoroscopic duration. Extra-PV PFA lesion sets using PFA should be tailored according to patient’s atrial substrate/ clinical context and requires larger studies to evaluate its utility.