Paroxysmal Atrial Fibrillation Ablation Using a Novel Variable-Loop Biphasic Pulsed Field Ablation Catheter Integrated With a 3-Dimensional Mapping System: 1-Year Outcomes of the Multicenter inspIRE…

Mattias Duytschaever, Tom De Potter, Massimo Grimaldi, Ante Anic, Johan Vijgen, Petr Neuzil, Hugo Van Herendael, Atul Verma, Allan Skanes, Daniel Scherr, Helmut Pürerfellner, Gediminas Rackauskas, Pierre Jaïs, Vivek Y. Reddy, Andrea Natale, Luigi Di Biase, Sebastien Knecht, Jan Petru, Georgios Kollias, Peter Lukac, Jim Hansen, Thomas Phlips

Background - The inspIRE study evaluated safety and effectiveness of a fully integrated biphasic pulsed field ablation (PFA) system with a variable loop circular catheter for the treatment of drug-refractory paroxysmal atrial fibrillation (AF). Methods - Subjects underwent pulmonary vein isolation (PVI) with the PFA system, using at least 12 applications per vein; adenosine/isoproterenol was administered to confirm entrance block. Wave I assessed initial safety, including for esophageal lesions, silent cerebral lesions (SCLs), and PV stenosis. Wave II (pivotal phase) tested i) primary safety - incidence of early onset primary adverse events (PAEs), and primary effectiveness - confirmed PVI with freedom from documented atrial arrhythmia at 12-months (12M). The study design specified an interim analysis to determine early success once 30 subjects reached 12M follow-up (FU) and all subjects reached 3M FU. Results - Across 13 centers in Europe/Canada, 226 subjects were enrolled, met criteria for safety and effectiveness evaluations and received PFA (Wave I: 40; Wave II: 186). Wave I demonstrated no esophageal thermal lesions or PV stenosis. Among 39 subjects with cerebral MRI, SCLs were detected in 4 of the first 6 subjects, after which workflow enhancements, including a 10s pause between PFA applications was implemented; subsequently, only 4 of 33 subjects had SCLs. In the Wave II phase, no PAE was reported. Upon declaring early success, 83 subjects reached 12M FU. With 100% entrance block, PVI without acute reconnection was achieved in 97.1% of targeted veins. For Wave II, the primary effectiveness endpoint per Kaplan Meier at the time of interim analysis was 70.9%; 12M freedom from symptomatic AF/atrial flutter/atrial tachycardia recurrence and repeat ablation was 78.9% and 92.3%, respectively. Total procedure and transpired PFA times were 70.1 ± 27.7 min and 26.7 ± 14.0 min, respectively. Conclusions - The inspIRE trial confirmed the safety and effectiveness of the novel mapping-integrated PFA system.