Dose-dependent ventricular lesion formation using a novel large-area pulsed field ablation catheter: A preclinical feasibility study
Thomas Kueffer, Daniela Casoni, Christine Goepfert, Olgica Beslac, Chiara Parodi, David A. Ramirez, Kara Garrott, Brendan Koop, Sean Coe, Nathan Hagstrom, Guillaume Gibert, Laurent Roten, Andreas Haeberlin, Tobias Reichlin
Abstract
BACKGROUND: Pulsed field ablation (PFA) has shown promising data in terms of safety and procedural efficiency for pulmonary vein isolation. Large-area focal PFA catheter designs might be suitable to deliver deep and durable lesions in ventricular myocardium. OBJECTIVE: We aimed to investigate the dose-response of a novel large-area focal 3-dimensional (3D)-enabled map-and-ablate PFA catheter for ventricular ablation in a chronic preclinical swine model. METHODS: An 8F catheter with a 9-mm hexaspline tip was used for 3D mapping of both ventricles in a porcine model. Using a PFA generator with a proprietary waveform optimized for the catheter, left and right ventricular lesions were placed with either a monopolar or bipolar ablation vector and with 1, 2, or 4 applications per site (2.0 kV/application). Tissue contact was ensured by intracardiac echocardiography and electrograms. The animals were kept alive for 1 week. Ablation lesions were assessed macroscopically after triphenyl tetrazolium chloride staining and by histopathology. RESULTS: A total of 69 chronic ventricular lesions from 7 pigs were available for analysis. By stacking 4 PFA applications rather than a single application, median chronic lesion depth increased from 4.8 mm (interquartile range [IQR], 4.1-5.6 mm) to 5.5 mm (IQR, 5.0-6.2 mm; P = .06) with bipolar ablation and from 4.9 mm (IQR, 4.4-5.2 mm) to 6.5 mm (IQR, 5.9-6.9 mm; P = .002) with monopolar ablation. On histologic evaluation, lesion borders were clearly demarcated, with vessels and nerves preserved. CONCLUSION: A novel large-area focal ablation catheter with the ability for 3D mapping and PFA was able to create dose-dependent deep ventricular lesions durable 1 week after ablation.