Impact of pulsed field ablation on outcome in obese patients undergoing pulmonary vein isolation for atrial fibrillation

Background Pulsed field ablation (PFA) is an established non-thermal ablation modality for pulmonary vein isolation (PVI) in atrial fibrillation (AF). PFA has shown efficacy comparable to cryoballoon ablation for PVI in patients with obesity (BMI ≥30 kg/m²). However, data comparing outcome after PFA-PVI between patients with obesity classes I-III are scarce. The objective of the study was to evaluate the impact of obesity class on outcome after PFA-PVI. Methods This retrospective study included a total of 144 patients with AF (median age: 66 [59–72] years; 57% male; 56% paroxysmal AF) who underwent first-time PFA-PVI between July 2022 and November 2024. According to obesity class, patients were assigned to group BMI-30 (BMI 30-34.9 kg/m²; n=85), group BMI-35 (BMI 35-39.9 kg/m²; n=35), or group BMI-40 (BMI ≥40 kg/m²; n=24). The primary endpoint was freedom from atrial arrhythmia (AF, atrial flutter, and atrial tachycardia) at 1 year, assessed by Holter monitoring at 3 and 12 months. Safety endpoints comprised cardiac tamponade, major bleeding requiring transfusion, pneumonia, stroke or transient ischemic attack, phrenic nerve palsy, major femoral access-site complications, acute kidney injury, and death. Results In group BMI-40, female sex and obstructive sleep apnea were significantly more prevalent compared with the other two groups (p<0.05). Freedom from atrial arrhythmia was similar across all groups (70.2% [BMI-30] vs. 65.7% [BMI-35] vs. 61.9% [BMI-40]; p=0.676). Subgroup analysis showed no significant difference between the 3 groups in paroxysmal (79.1% [BMI-30] vs. 72.0% [BMI-35] vs. 68.4% [BMI-40]; p=0.707) and persistent AF (61.2% [BMI-30] vs. 50.0% [BMI-35] vs. 54.5% [BMI-40]; p=0.635). Serious adverse events were observed in 9 patients (6.3%), with no significant differences between the 3 groups (p=0.138). Of the 9 serious adverse events, 4 (2.8%) were major femoral access-site complications. The remaining 5 serious adverse events were pneumonia (n=2 [1.4%]), stroke (n=1 [0.7%]), and acute kidney injury (n=2 [1.4%]). Conclusion PFA-PVI in patients with obesity classes I-III may result in comparable clinical outcome, despite the higher prevalence of comorbidities in patients with obesity class III. Most adverse events were access-site related. Further studies with larger sample sizes and continuous rhythm monitoring may be necessary to confirm these results. Figure 1. Freedom from atrial arrhythmia at 1 year. Kaplan-Meier analysis of freedom from atrial arrhythmia in group BMI-30, group BMI-35, and group BMI-40: (A) All patients, (B) Patients with paroxysmal atrial fibrillation, (C) Patients with persistent atrial fibrillation. AF = atrial fibrillation