Redo ablation procedures to treat recurrent atrial arrhythmias via a pentaspline pulsed field ablation catheter: a prospective, multicenter experience

BACKGROUND: Patients undergoing atrial fibrillation (AF) catheter ablation may require redo procedures involving pulmonary vein (PV) re-isolation and/or ablation of extra-PV sites. Pulsed field ablation (PFA) offers a highly selective energy source for cardiac tissue, with the potential to reduce collateral damage to adjacent structures. This study aimed to evaluate the feasibility and efficacy of redo ablation using a pentaspline PFA system.

METHODS: Patients undergoing redo procedures with a pentaspline PFA system at three international centers were enrolled. A workflow was established based on rhythm at presentation: sinus rhythm (Group 1), atrial flutter/atrial tachycardia (Group 2), or AF (Group 3). Propensity score matching was used for comparison between PFA- and RF-based redo ablations.

RESULTS: A total of 117 patients were included (Group 1: 64, Group 2: 18, Group 3: 35). PV re-isolation was required in 71.9% and 72.2% of Group 1 and 2 patients, respectively. PFA terminated all cases of non-cavotricuspid isthmus dependent flutter and 45.7% of cases of AF. One major complication (0.9%; frontal cerebral hematoma) was documented. Freedom from atrial tachyarrhythmias at 12 months was 78.3% (95% CI 69.6-84.8%) without statistically significant differences among groups (Group 1: 85.7%; Group 2: 77%; Group 3: 65.5%; p = 0.053). PFA led to similar arrhythmia freedom compared to RF, but with significantly shorter procedural and dwelling times.

CONCLUSION: The adoption of a pentaspline PFA system for repeat ablation procedures was feasible, safe, and effective at 1-year follow-up. No clinical differences were observed between PFA and RF; however, redo PFA cases were significantly shorter.