Transseptal puncture for catheter ablation of atrial fibrillation in patients with septal occluder devices

Transseptal puncture (TSP) is critical for atrial fibrillation (AF) ablation. However, patients with atrial septal occluders (ASO) for atrial septal defects (ASD) or persistent foramen ovale (PFO) pose unique challenges. This study aimed to evaluate the peri- and post-procedural safety, AF recurrence, and incidence of newly developed ASD/PFO up to 12 months post-procedure. This multicenter, prospective observational study included 59 patients (mean age 61.2±12.1 years, 56% male) with drug-refractory AF who underwent pulmonary vein isolation (PVI) between 2019 and 2024. Of these, 38 had ASDs and 21 had PFOs, with ASOs in situ. All punctures (Single TSP) were performed under fluoroscopic guidance. The majority of TSP-position in IAS related to the ASO was inferior-posterior to the ASO (66.1%) or inferior-anterior (23.7%). In the case of failure of the inferior part, puncture was performed in superior-posterior puncture (8.5%) or puncture through the occluder (1.7%). The mean ablation time was 14.9±8.4 minutes, including radiofrequency (83.0%), cryoballoon (11.9%), and pulsed-field ablation (5.1%). No major complications were observed, except for one transient phrenic nerve palsy during cryoballoon ablation, which recovered intra-procedurally. Voltage mapping revealed no additional substrate related to the occluder. During a 12-month follow-up, 7 patients (11.9%) experienced AF recurrence. TSP and PVI are safe and can be safely performed in patients with an ASO. No additional substrate related to the occluder was seen. While no direct comparison was made, outcomes align with existing literature. Further studies are needed.