Outcomes Following Diffuse Posterior Left Atrial Ablation with Low-Flow, Medium-Power and Short-Duration for Atrial Fibrillation

Objective: This study aimed to assess the safety and efficacy of diffuse left atrial posterior wall isolation (PWI) with low-flow, medium-power, short-duration (LF-MPSD) ablation in atrial fibrillation (AF) management. Background: LF-MPSD ablation at the posterior left atrium during pulmonary vein isolation (PVI) was previously shown to create transmural lesions without esophageal injury, but its clinical safety and efficacy were not tested for diffuse PWI. Methods: We retrospectively studied patients undergoing LF-MPSD ablation for AF (PVI + diffuse PWI) between 8/2017 and 12/2019. Clinical characteristics and procedural data were collected. Kaplan-Meier survival analysis was performed to study AF/atrial flutter (AFL) recurrence. Ablation data were analyzed in patients who underwent a repeat AF/AFL ablation. Results: A total of 137 patients were included in the study. Periprocedural complications were rare, and there were no cases of stroke or significant esophageal injury. Among the 126 patients who were followed after PVI+PWI, 30.2% had AF/AFL recurrence during a median follow up of 14 months. Eighteen patients received redo ablations: 2 patients (11.1%) had PV reconnection, and 11 patients (61.1%) had partial PW conduction recovery - which frequently occurred in the upper and rightward regions. PW-dependent AFL occurred in only 2 of the 11 (18.1%) patients despite partial conduction recovery. Conclusion: Diffuse PWI with LF-MPSD protocol is safe with reasonable clinical efficacy. Among patients undergoing repeat ablations, there was a high rate of PVI durability, but partial posterior wall conduction recovery was common but was uncommonly substrate for AFL.