PO-01-186 PERCUTANEOUS LEFT ATRIAL APPENDAGE CLOSURE AND PULSED-FIELD ISOLATION WITH A NOVEL DEVICE SYSTEM IN A CANINE MODEL: FEASIBILITY, SAFETY, ENDOTHELIALIZATION, AND LESION DURABILITY EVALUATION

Abstract

Left atrial appendage (LAA) electrical isolation (LAAEI) can reduce the recurrence of atrial fibrillation in patients with LAA firing. However, LAAEI using either radiofrequency or cryoablation endured a <95% acute success rate and a further lower durability rate, with potential harm to the left phrenic nerve and left circumflex artery (LCXa). LAAEI is an independent risk factor for left atrial thrombogenesis and stroke, which can be effectively decreased by LAA closure (LAAC). To investigate the feasibility, safety, and efficiency of the percutaneous left atrial appendage closure and pulsed-field isolation with a novel device system. The E-SeaLATM device system was utilized in 18 canines: Group 1a - LAAEI with initial parameters (6 cases), Group 1b - LAAC+LAAEI with initial parameters (3 cases), Group 2a - LAAEI with optimized parameters (3 cases), and Group 2b – LAAC+LAAEI with optimized parameters (6 cases). Device position and LAAEI rate in the acute phase, and endothelialization, LAAEI durability, and stenosis of LCXa in the follow-up phase were evaluated. Acute LAAEI was achieved in all 18 canines. LAA reconnected in 8/9 cases (88.9%, at 1 week to 6 months) in Group 1, and 2/9 (22.2%, at 1-6 months) in Group 2. Full endothelialization was observed in 1/3 cases at 3 months and 6/6 at 6 months. No device displacement occurred after LAAC. No LCXa spasm or fixed stenosis was detected. Mild pericardial effusion (1-2mm) without hemodynamic influence was noticed in 2/18 (11.1%) in the acute phase, which spontaneously resolved in the follow-up phase. The novel E-SeaLATM system could effectively occlude and electrically isolated the LAA in the canine model, with full endothelialization at 6 months, and satisfactory LAAI durability using the optimized pulsed field parameters. Future studies should address feasibility, efficacy, and safety in humans.