Safety and Chronic Atrial Lesion Formation With a Large-Tip, Contact-Force-Sensing Multipolar Pulsed Field Ablation...

Integration of catheter-tissue contact force with pulsed field ablation (PFA) dosing is essential for achieving safe and durable lesion formation with contact force sensing catheters in ventricular models. However, data on the use of these catheters for atrial ablation remain limited. This study evaluated the procedural safety and 30-day lesion characteristics of atrial PFA delivered with the OMNYPULSE ablation catheter in a porcine model.

Twelve pigs were randomized to receive either 6 (×6 or Group A) or 12 (×12 or group B) PFA applications per ablation. Following 3-dimensional electroanatomic mapping, PFA was delivered to the right superior and inferior pulmonary veins, cavotricuspid isthmus, right atrial posterior wall, left atrial roof, and mitral annulus. Procedural safety was assessed acutely, and lesion characteristics were evaluated on 30-day histology. Maximum transmurality extent (MTE) was defined as >80% of the lesion span exhibiting continuous endocardial-to-epicardial fibrosis within representative histological sections.

Adequate catheter-tissue contact was achieved during PFA delivery (contact force, 28±15 g). No acute procedural complications were observed. At 30 days, PVs and right atrial sites (ie, cavotricuspid isthmus and right atrial posterior wall) demonstrated near-complete MTE regardless of PFA dosing. In contrast, MTE was significantly lower at the mitral annulus and LA roof compared with other sites (44±30% and 21±26%, respectively; P<0.001). Increasing the number of PFA applications (×12) resulted in a remarkable improvement in MTE at these locations, with MTE increases of up to 68% compared with ×6 dosing at these sites.

Atrial PFA using the OMNYPULSE catheter was feasible and safe in a porcine model. However, lesion transmurality varied by atrial location and was dose-dependent at select sites, underscoring the need for site-specific PFA dosing strategies. Further studies are warranted to define optimal PFA parameters for consistent atrial lesion formation.