First-in-human assessment of atrial fibrillation ablation using the circular multielectrode pulsed field ablation catheter with a new impedance-based proximity indicator

Background/Introduction Tissue contact is critical for effective energy delivery and durable lesion creation with pulsed field ablation (PFA). Currently operators rely on fluoroscopy and intracardiac echocardiography (ICE) to evaluate catheter-tissue contact with the fixed loop multielectrode PFA catheter. However, these visualization modalities are limited in their ability to clearly display contact across the entire catheter array. Purpose This prospective, first-in-human study evaluated the performance of a new impedance-based tissue proximity indicator that measures and displays real-time impedance changes at each catheter electrode on the circular multielectrode PFA system. Methods This analysis included data from 11 patients indicated for atrial fibrillation (AF) that were enrolled September - October 2025 at a single center. All patients underwent pulmonary vein isolation (PVI) using a circular multielectrode PFA system (PulseSelect) and investigational proximity adaptor. Impedance-based tissue proximity indication on the generator screen was confirmed against ICE images and electrogram recordings. In 5 patients, data were recorded, but proximity feedback was not used to inform catheter positioning. The next 6 patients utilized feedback from the proximity indicator to optimize catheter positioning during the normal case workflow. The number of electrodes in contact with tissue immediately before energy delivery based on proximity indication was evaluated across cases. Results A total of 11 patients (64.2±10.0 years, 73% male, 82% paroxysmal AF) received de novo AF ablation. All procedures were performed using general anesthesia. Mean total procedure time was 116.5±18.7 minutes, with an average "first-to-last" energy application time of 33.7±11.0 minutes and mean fluoroscopy time of 16.2±3.5 minutes. Acute PVI was achieved in 100% of subjects. No serious adverse events (AEs) occurred. The mean number of electrodes indicating tissue proximity immediately prior to energy delivery increased from 63% without proximity feedback to 75% when proximity feedback was used to optimize catheter positioning (Figure 1). Conclusion This analysis demonstrates the clinical performance of local impedance recordings for assessing catheter-tissue contact with the circular multielectrode PFA catheter. Visual feedback from the proximity indicator increased the number of electrodes in close proximity to tissue during energy delivery.