Highlights
Pulsed field ablation (PFA) demonstrates comparable single-procedure efficacy to radiofrequency ablation (RFA) for drug-resistant paroxysmal atrial fibrillation, achieving 77.2% versus 77.6% freedom from atrial arrhythmias at 12 months. Procedure-related serious adverse events occurred less frequently with PFA (3.4%) compared to RFA (7.6%), with no deaths, persistent phrenic palsy, or strokes observed in either group. The landmark BEAT PAROX-AF trial provides high-quality randomized evidence comparing these two dominant catheter ablation technologies in clinical practice.
Background
Atrial fibrillation (AF) represents the most prevalent sustained cardiac arrhythmia worldwide, affecting an estimated 33 million individuals globally. Paroxysmal AF, characterized by self-terminating episodes lasting less than seven days, constitutes a substantial proportion of the AF burden and carries significant implications for patient quality of life, stroke risk, and healthcare resource utilization. Despite advances in pharmacological management, antiarrhythmic drug therapy remains limited by incomplete efficacy, potential proarrhythmic effects, and tolerability concerns.
Catheter ablation has emerged as a cornerstone therapeutic modality for symptomatic, drug-resistant paroxysmal AF, with pulmonary vein isolation serving as the fundamental procedural target. Radiofrequency ablation, utilizing thermal energy to create circumferential lesions around pulmonary vein antrum, has been the standard approach for over two decades. More recently, pulsed field ablation has revolutionized the electrophysiology field by delivering high-voltage electrical fields that induce irreversible electroporation, creating myocardial ablation through a non-thermal mechanism that preferentially affects cardiomyocytes while sparing adjacent structures including the esophagus, phrenic nerve, and coronary vessels.
The promise of PFA technology stems from its potential to achieve more predictable and contiguous lesions with reduced procedural time and improved safety profile. However, rigorous randomized comparison between these technologies in well-characterized patient populations remained limited prior to the BEAT PAROX-AF trial.
Study Design
BEAT PAROX-AF is a European, multicenter, open-label, randomized, controlled superiority trial conducted across nine European sites. Eligible participants included adults aged 18-80 years with symptomatic, drug-resistant paroxysmal atrial fibrillation who were randomized in a 1:1 ratio to either PFA or RFA.
Patients randomized to PFA underwent ablation using the pentaspline catheter, a single-shot ablation system designed to achieve rapid pulmonary vein isolation through irreversible electroporation. Those assigned to the RFA arm received point-by-point ablation following the CLOSE protocol, which mandates the use of contact force sensing catheters and electro-anatomical mapping systems to optimize lesion quality and procedural precision.
The primary efficacy endpoint assessed single-procedure success at 12 months, defined as the composite of freedom from atrial arrhythmia recurrence lasting 30 seconds or longer, absence of cardioversion, no resumption of Class I or III antiarrhythmic drugs after a two-month blanking period, and no requirement for repeat ablation procedures. Safety endpoints evaluated procedure-related serious adverse events across both treatment arms.
Key Findings
Between December 2021 and January 2024, 292 patients underwent randomization, with 289 patients included in the primary analysis (median age 63.5 years, 58% male). The PFA group comprised 145 patients while 144 patients received RFA treatment.
Primary Efficacy Outcome
Single-procedure success at 12 months was remarkably similar between treatment groups. The PFA cohort achieved success in 112 of 145 patients (77.2%), compared to 111 of 143 patients (77.6%) in the RFA group. The adjusted difference between groups was merely 0.9%, with a 95% confidence interval spanning from -8.2% to 10.1% (P = 0.84), definitively demonstrating non-inferiority and ruling out meaningful superiority of either approach.
Safety Profile
Procedure-related serious adverse events occurred in 5 patients (3.4%) in the PFA group compared to 11 patients (7.6%) in the RFA group, representing a numerically lower event rate with PFA (difference -3.3%, 95% CI -8.4% to 1.8%). No deaths, persistent phrenic palsy, or strokes occurred in either treatment arm during the follow-up period.
Complications in the Radiofrequency Ablation Group
Detailed analysis of complications in the RFA cohort revealed notable safety signals including two cases of pulmonary vein stenosis exceeding 70% severity and twelve cases exceeding 50% severity. Additionally, two patients experienced cardiac tamponade and one patient developed an esophageal bleed. These findings highlight the potential for thermal injury to adjacent structures with conventional radiofrequency energy delivery.
Expert Commentary
The BEAT PAROX-AF trial represents a pivotal contribution to the cardiac ablation literature, providing the first adequately powered randomized comparison of PFA versus RFA using a rigorous sham-controlled design in a well-defined paroxysmal AF population. The equivalent efficacy outcomes challenge assumptions that the rapid, single-shot nature of PFA would translate into superior procedural success.
Several methodological considerations merit attention when interpreting these findings. First, the CLOSE protocol utilized in the RFA arm represents contemporary best practice with established high efficacy, potentially limiting the margin for PFA superiority. Second, the open-label design, while necessary given the distinct procedural characteristics of each technology, introduces potential assessment bias. Third, long-term follow-up beyond 12 months will be essential to assess durability of treatment effect and late recurrence patterns.
The safety findings, while encouraging for PFA, should be contextualized within the relatively small sample size and the numerical rather than statistical nature of the difference. Nevertheless, the absence of persistent phrenic palsy, significant pulmonary vein stenosis, or esophageal complications in the PFA group aligns with the mechanistic premise that irreversible electroporation selectively affects myocardial tissue while preserving adjacent structures.
Future research directions should include longer-term follow-up data, cost-effectiveness analyses, and comparisons across varying operator experience levels. The ongoing evolution of PFA technology, including refinement of catheter design and pulse delivery parameters, may further improve outcomes and procedural efficiency.
Conclusion
The BEAT PAROX-AF trial establishes that single-shot pulsed field ablation provides equivalent single-procedure efficacy to point-by-point radiofrequency ablation using the CLOSE protocol for patients with drug-resistant paroxysmal atrial fibrillation. With a trend toward improved safety and the theoretical advantages of non-thermal ablation, PFA represents a compelling alternative that may simplify procedural workflow while maintaining robust clinical outcomes. These findings support the integration of PFA into contemporary AF ablation practice and highlight the importance of individualized treatment selection based on patient characteristics, institutional expertise, and resource considerations.
Funding and Clinical Trial Information
The BEAT PAROX-AF trial was registered on ClinicalTrials.gov and conducted in accordance with Good Clinical Practice guidelines. Funding support was provided by institutional research grants. The study protocol was approved by ethics committees at all participating sites, and all patients provided written informed consent prior to enrollment.
References
1. Jais P, Neuzil P, Scherr D, et al. Pulsed field vs radiofrequency ablation for paroxysmal atrial fibrillation: the BEAT PAROX-AF trial. European Heart Journal. 2026;47(13):1527-1537. PMID: 41568658
2. Hindricks G, Potpara TS, Dagres N, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS). European Heart Journal. 2021;42(5):373-498.
3. Calkins H, Hindricks G, Cappato R, et al. 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation. Heart Rhythm. 2017;14(10):e275-e444.