Single-Shot Versus Focal Dual-Energy Pulsed Field-Based Ablation for Atrial Fibrillation

Catheter ablation via pulmonary vein isolation (PVI) is an established therapy for symptomatic paroxysmal and persistent atrial fibrillation. In recent years, pulsed-field ablation (PFA) has emerged as an innovative ablation technology. Unlike thermal ablation using radiofrequency or cryoablation, PFA relies on irreversible electroporation of the cell membrane, thereby enabling the selective ablation of cardiomyocytes while largely sparing adjacent structures such as the esophagus, phrenic nerve, and pulmonary veins. Clinical studies and registry data have demonstrated high efficacy and a favorable safety profile for PFA.

Various catheter systems are now available for performing PVI via PFA. These include single-shot systems, which facilitate rapid pulmonary vein isolation through a standardized and efficient workflow. Additionally, focal dual-energy catheters have been developed that combine pulsed-field ablation and radiofrequency ablation within a single catheter. These systems allow for tailored lesion delivery using electroanatomical mapping systems and may offer advantages, particularly in cases of complex anatomy or additional arrhythmogenic substrate.

Both single-shot and focal dual-energy systems have demonstrated high acute success rates and promising clinical outcomes in studies to date. However, there are currently no direct, prospective, randomized comparisons between the two ablation strategies. In particular, it remains unclear whether there are differences between the two approaches regarding long-term freedom from atrial arrhythmias, procedural efficiency, or safety.

Patients with persistent atrial fibrillation and those with a high comorbidity burden face an increased risk of atrial arrhythmia recurrence despite successful pulmonary vein isolation. While single-shot systems enable a standardized, rapid, and reproducible ablation procedure, focal dual-energy systems-due to their greater flexibility-may offer advantages in cases of complex anatomy and for individually tailored ablation strategies.

To date, there are no randomized clinical trials directly comparing these two ablation approaches. In particular, there is a lack of prospective data regarding patients at high risk for atrial arrhythmia recurrence. This study aims to bridge this evidence gap by investigating whether ablation using single-shot PFA is non-inferior to ablation using a focal dual-energy catheter in terms of clinical efficacy in patients at high risk of recurrence.

Inclusion criteria

• Age ≥ 18 years
• First-time pulmonary vein isolation
• Symptomatic atrial fibrillation:

• Paroxysmal atrial fibrillation (≥ 2 episodes in the last 6 months) and one of the following:

CHA2DS2VA score ≥ 2, ≥ 1 cardioversion in the last 6 months or Left atrial (LA) diameter ≥ 45 mm

o or persistent atrial fibrillation (≥ 1 episode in the last 6 months)

Exclusion criteria

• Atrial fibrillation due to reversible or non-cardiac causes
• Severe mitral or tricuspid valve regurgitation requiring therapy
• Previous left atrial endocardial or epicardial ablation
• Pregnancy or breastfeeding
• Lack of opportunity for reliable study participation