Initial experience with a novel pulsed field ablation catheter for ablation of atrial fibrillation: procedural findings and acute safety

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Currently employed catheters for treatment of symptomatic atrial fibrillation (AF) leverage thermal energy to ablate the myocardium. Despite excellent acute success rates, the non-selective nature of thermal injury has been associated with frequent AF recurrences and complications such as pulmonary vein stenosis and thermal damage to adjacent structures. Recently, a novel, non-thermal ablative modality has been introduced for the treatment of AF: pulsed field ablation (PFA). The selective nature of PFA translates in the ability to perform full transmural lesions whilst sparing adjacent tissues and structures, making PFA an attractive solution to limitations faced with thermal energy sources. Although several pre-clinical studies investigated the safety and feasibility of PFA, limited reports have been published so far describing the clinical application of this novel catheter technology. Purpose In this study we present our initial experience with a pulsed field ablation catheter and describe procedural findings and acute safety of the first 68 patients treated at our center. Methods We investigated the first 68 patients treated for symptomatic AF at our center using pulsed field ablation between July 2021 and January 2022. Procedural findings at the time of ablation are presented. Procedure-related complications are reported. Qualitative analysis of electrograms and electrophysiological maps before and after ablation are also provided. Lastly, learning curves of operators who performed more than 10 procedures are described. Results Mean age of patients was 63.1±9.2 years, and most were men (57.4%). Most patients suffered from paroxysmal AF (79.4%). The median CHA2DS2-VASc score was 2.0 (1.0; 3.0) and mean left-atrium (LA) volume index was 33.0±8.3 ml/m2. All procedures were performed using conscious sedation. In 63/68 patients ablation of the PVI was performed and in 5/68 patients additional ablation of the left atrial posterior wall was performed. 3D electroanatomic mapping was performed during 10/68 procedures which lasted on average 107.3±15.5 min. Procedures where no mapping was performed lasted on average 48.5±20.7 min. Mean LA time was 39.9±19.0 min. Mean number of applications per pulmonary vein (PV) were 8.6±1.1. In all patients (100%) PVs were confirmed to be isolated. Four different operators performed the ablations: operator 1 performed 25/58 procedures (36.8%), operator 2 28/58 (41.2%), operator 3 9/58 (13.2%), and operator 4 6/58 (8.8%). The learning curves of both operator 1 and operator 2 showed negligible variation of performance over time (R2: Operator 1 = 0.181; Operator 2 = 0.078). The only complications reported were two cases of bleeding at the percutaneous access site of the femoral vein. Conclusions Our initial experience with a PFA catheter in 68 patients shows that PFA is a safe, quick, easy-to-learn, and effective ablation technique for the treatment of symptomatic AF.