Abstract 15077: Reconnection of Pulmonary Veins and Left Atrial Posterior Wall Following Catheter Ablation for Atrial Fibrillation in Real-World Patients: Registry Data From a High-Volume Center

Introduction: Durable isolation of the pulmonary veins (PV) and the left atrial posterior wall (LAPW) are considered as key determinants of long-term success after catheter ablation in AF patients. Objective: We aimed to evaluate the PV and LAPW reconnection rate in real-world patients undergoing redo-ablation at our center. Methods: Consecutive AF patients that underwent their first AF ablation at our center from 2015-19 were included in this analysis. At the index procedure, all received electrical isolation of PVs and the LAPW area between the PVs, using radiofrequency (RF) ablation. Procedure was conducted with 3.5-mm irrigated-tip catheter guided by circular mapping catheter, intra-cardiac echocardiography and a 3-D mapping system. RF energy was delivered with a maximum temperature setting of 42 0 C, contact force of 10g and a power of up to 45W. Posterior wall isolation was performed using multiple ablation points covering the whole posterior wall. An esophageal probe was utilized in all patients to monitor esophageal temperature during ablation in the LAPW in close proximity to the esophagus. Complete abolition of all PV potentials rather than decrease in the amplitudes was the end point and confirmed by entrance and/or exit block. All patients were followed up prospectively for 2 years with quarterly evaluation during the first year and bi-annually afterwards and the data was collected in our IRB-approved AF registry. Recovery of conduction in the PVs and LAPW were assessed at the redo procedure using pacing or incremental isoproterenol infusion of 20- 30μg/min for 15-20min. Results: During the study period, 6,817 AF ablation procedures were performed at our institution of which 3,113 AF patients undergoing their first catheter ablation were included in the analysis and prospectively followed up for 2 years. Baseline characteristics of the study population is given in Table 1. At 23.1±12.8 months of follow-up, 614 (19.7%) patients had received redo-ablation, of which 139 (22.6%) had one or more PV or LAPW reconnected. Conclusion: In this series, with experienced operators performing the procedures, the rate of recovery of conduction in the PVs and LAPW was low compared to the reported high incidence rate in the literature.