Comparison of Re-Do Ablations of Atrial Fibrillation or Atypical Atrial Flutter Using Point-by-Point Pulsed Field Ablation or Radiofrequency Ablation

Background: The recurrence rate of atrial fibrillation (AF) after initial pulmonary vein isolation (PVI) remains approximately 20% at one year, regardless of the ablation technique used. For these patients, achieving a lasting sinus rhythm can be challenging and often necessitates more extensive ablation strategies. This study aims to compare outcomes between redo PVI procedures using focal pulsed field ablation (PFA) and radiofrequency (RF) ablation.

Methods: This observational cohort study included 116 patients who underwent redo PVI between 2019 and 2023, with 76 patients receiving RF ablation and 40 undergoing focal PFA using the Centauri PFA System (CardioFocus Inc., Marlborough, MA, USA). Key procedural characteristics, complication rates, and long-term outcomes were analyzed and compared.

Results: Baseline characteristics and cardiovascular risk profiles were similar between the groups. Both ablation methods were effective in achieving pulmonary vein re-isolation, as well as creating additional ablation lines. Notably, a significantly higher number of additional ablation lines, particularly posterior box ablation, were performed in the PFA group, reflecting the investigator’s preference based on PFA’s favorable tissue penetration and safety profile near the esophagus. Procedure duration was longer with PFA (128.3 ± 42.73 min vs. 111.9 ± 31.41 min; p=0.02), while fluoroscopy times were comparable. Complications were minimal across both groups. AF recurrence within the first year was similar, observed in 27.63% of RF cases and 30% of PFA cases (p=0.79), suggesting comparable efficacy. Eighteen (23.68%) patients in the RF group and 8 (20%) in the PFA group required further redo ablations after the index procedure. In the RF group, 55.55% of patients showed complete isolation of previous ablation lines, whereas gaps were observed in the remaining cases, particularly in the pulmonary vein isolations. In the PFA group, 25% of patients had complete isolation of all previous lines, with gaps primarily detected in the anterior line in the remaining cases.

Conclusion: Focal PFA using the Centauri generator shows comparable safety to RF ablation and similar AF recurrence rates at one year, supporting its use as an effective alternative for rhythm control in persistent atrial arrhythmias. The findings reveal a notable incidence of gaps in the anterior mitral line following focal PFA ablation, indicating an area for potential refinement in future procedures