Esophageal safety of pulsed field versus radiofrequency ablation including posterior wall isolation in persistent atrial fibrillation: a blinded endoscopic study

Background Posterior wall isolation in patients with persistent atrial fibrillation (AF) using thermal ablation techniques is associated with an increased risk of esophageal injury, which remains a major safety concern. Despite esophageal temperature monitoring and energy modulation, radiofrequency (RF) ablation of the posterior wall may result in thermal damage. Pulsed field ablation (PFA), a non-thermal modality with myocardial selectivity, may reduce collateral injury while allowing effective posterior wall ablation. Comparative data with blinded endoscopic assessment remain limited. Purpose To compare esophageal injury, procedural characteristics, and periprocedural safety of pulsed field ablation versus radiofrequency ablation in patients with persistent AF undergoing pulmonary vein isolation (PVI) plus posterior wall isolation. Methods This single-center comparative study included 120 patients with persistent atrial fibrillation undergoing first-time catheter ablation with a standardized strategy of PVI combined with posterior wall isolation. Sixty patients were treated using pulsed field ablation and sixty using radiofrequency ablation. In the radiofrequency group, esophageal temperature was continuously monitored, and energy delivery was interrupted in case of temperature increase. In a predefined subgroup of 60 patients (30 PFA, 30 RF), systematic upper gastrointestinal endoscopy was performed before and after ablation to identify new esophageal lesions. Endoscopic assessment was performed by operators blinded to the ablation energy source. Procedural duration and major periprocedural complications were prospectively recorded. Results Baseline characteristics were comparable between groups. New esophageal lesions were detected in 30% of patients treated with radiofrequency ablation, whereas no new esophageal lesions were observed in the pulsed field ablation group (0%). Mean procedural duration was significantly longer with radiofrequency ablation (120 ± 8 minutes) compared with pulsed field ablation (45 ± 5 minutes). Major periprocedural complications occurred in three patients in the radiofrequency group, including two cases of pericardial bleeding not requiring drainage and one air embolism. No major complications were observed following pulsed field ablation. Conclusion In patients with persistent atrial fibrillation undergoing pulmonary vein isolation plus posterior wall isolation, pulsed field ablation demonstrated a markedly improved esophageal safety profile compared with radiofrequency ablation, even with esophageal temperature monitoring in the radiofrequency group, and was associated with substantially shorter procedural duration.