Procedural safety and outcome of additional left atrial posterior wall ablation using pulse field ablation for atrial fibrillation

Abstract Introduction Pulsed field ablation (PFA) has recently been shown to be comparable to radiofrequency ablation and cryoablation in terms of acute safety and outcome for pulmonary vein isolation (PVI) for atrial fibrillation (AF). Efficacy and safety of additional left atrial posterior wall ablation (LAPWA) is unknown. We hereby report safety profile and short-term success at 6 months. Methods Consecutive patients with paroxysmal or persistent atrial fibrillation who underwent PFA were included. Procedures were performed under conscious sedation or general anaesthesia, with or without intracardiac echocardiography/ pre- or post-ablation electroanatomic mapping at the operators’ discretion. Safety endpoints included all-cause death within 30 days, cardiac tamponade, stroke/ TIA, MI, diaphragmatic paralysis, AE fistula. Primary efficacy endpoint was arrhythmia recurrence after 90 days blanking period at 6 months. LAPWA was performed using 2.0 kV biphasic waveforms, 2 deliveries for each application site. The lesion set depended on the patient’s AF ablation history, LA size, and anatomy. After LA mapping post PVI (index or re-do), 2 anchor lesions per vein extending to the LAPW were deployed. A lesion set was then performed between the anchor lesions on the LAPW (upper and lower row) with the catheter in a flower configuration and the intention of 50% overlap for the neighbouring application sites at 3D EAM. Results Seventy-two (76% males) patients underwent PFA for AF, 55 (76.4%) were paroxysmal and 4 (5.6%) were redo cases. 19 (72%) underwent additional LAPWA. LAPWA was more likely performed in patients with persistent AF (57.9% vs 11.3%, p0.001), require GA (p=0.043), with 100% EAM use (p=0.026). While total PFA applications was expectedly higher in the LAPWA group (65.7 ± 12.4 vs 42.9 ± 9.0, p0.001), there were no significant differences in PFA dwell time in LA (44.2 ± 14.8 vs 42.3 ± 15.5min, p=0.628), procedural time (121.3 ± 43.8 vs 119.2 ± 49.4min, p=0.866) and fluoroscopic dose, AK (130 ± 107 vs 139 ± 102mGy, p=0.748). Average number of applications required for LAPW was 18 applications. LAPW isolation was acutely successful in all 19 patients on EAM. There were 6 inpatient complications of which all happened in the non-LAPWA group and unrelated to PFA. Arrhythmia recurrence was comparable at 6 months (11.1% vs 8.9%, p=1.00). Conclusion Additional LAPWA on top of PVI using PFA is safe with excellent acute isolation of posterior wall and does not increase procedural nor fluoroscopic duration. Short term outcome appears comparable and LAPWA may be useful especially in patients with persistent AF who may not be able to tolerate long procedures but will benefit from durable rhythm control.