Evaluation of Pulsed Field Ablation versus Conventional Thermal Ablation for Pulmonary Vein Isolation in Paroxysmal Atrial Fibrillation: Acute Procedural Efficacy, Safety Profile, and One-Year Rhythm Outcomes from a Randomized Controlled Trial

Abstract Background: Pulmonary vein isolation (PVI) remains the cornerstone of catheter ablation for paroxysmal atrial fibrillation (PAF). Conventional thermal ablation techniques, including radiofrequency and cryoballoon ablation, are effective but carry risks of collateral tissue injury. Pulsed field ablation (PFA), a novel non-thermal energy modality based on electroporation, has demonstrated myocardial selectivity and a potentially improved safety profile. However, randomized comparisons between PFA and conventional thermal ablation in PAF remain limited. Objectives: To compare the acute procedural efficacy, safety profile, and one-year rhythm outcomes of PFA versus conventional thermal ablation for PVI in patients with PAF. Methods: In this prospective, multicenter, randomized controlled trial, 286 patients with symptomatic PAF refractory to at least one antiarrhythmic drug were randomly assigned (1:1) to undergo PVI using either PFA or conventional thermal ablation (radiofrequency or cryoballoon, at operator discretion). The primary efficacy endpoint was acute procedural success, defined as durable electrical isolation of all pulmonary veins confirmed by entrance and exit block. The primary safety endpoint was the incidence of major procedure-related complications within 30 days. Secondary endpoints included procedural time, fluoroscopy exposure, atrial arrhythmia recurrence at 12 months, and quality-of-life measures. Continuous rhythm monitoring was performed using periodic Holter monitoring and implantable loop recorders in a subset of patients. Results: Acute PVI success was achieved in 98.6% of patients in the PFA group and 96.5% in the thermal ablation group (p = 0.21). PFA was associated with significantly shorter procedural time (78 ± 22 minutes vs 105 ± 30 minutes, p < 0.001) and reduced fluoroscopy exposure (p = 0.003). Major complication rates were lower in the PFA group (1.4% vs 5.6%, p = 0.04), primarily driven by reduced incidence of esophageal injury and phrenic nerve palsy. At one-year follow-up, freedom from atrial arrhythmia recurrence without antiarrhythmic drugs was observed in 79% of PFA-treated patients compared with 74% in the thermal ablation group (hazard ratio [HR] 0.82; 95% confidence interval [CI], 0.56–1.20; p = 0.30). Quality-of-life scores improved significantly in both groups, with no between-group differences. Conclusions: Pulsed field ablation demonstrated comparable acute efficacy and one-year rhythm outcomes to conventional thermal ablation for PVI in patients with PAF, with shorter procedural times and a more favorable safety profile. These findings support PFA as a promising alternative ablation modality and highlight its potential to improve procedural safety in AF ablation strategies. Longer-term follow-up studies are warranted to confirm durability and clinical benefit.