First multicenter Japanese registry on tissue proximity-guided pulsed field ablation: Procedural safety and mid-term outcomes

Background Pulsed field ablation (PFA) is a novel therapy for atrial fibrillation (AF) with myocardial selectivity and safety. The VARIPULSE catheter (variable-loop circular catheter [VLCC]; Biosense Webster, Inc.) was recently introduced in Japan, but multicenter real-world data remain scarce. Objective This study aimed to evaluate procedural features, acute safety, and early outcomes of tissue proximity indication (TPI)-guided PFA under structured training and standardized protocols. Methods We retrospectively analyzed 387 consecutive patients with AF (66.4 ± 10.9 years, 69% male, 87.1% paroxysmal) undergoing initial pulmonary vein isolation (PVI) with the VLCC at 10 Japanese centers (April 2024-May 2025). TPI-guided first-pass PVI targeted ≥12 applications per vein in 4 sets (proximal/distal), with additional ablation at TPI-negative sites. Operators received training and followed a harmonized workflow emphasizing TPI guidance and sheath management. Results First-pass PVI was achieved in 360 patients (93.0%). After limited touch-up (6.9 ± 3.6 applications), complete PVI was obtained in all. Mean PVI time was 32.1 minutes, procedure duration 89.7 minutes, and median fluoroscopy time 3.0 minutes. Three patients (0.8%) had vascular complications; no tamponade, stroke, transient ischemic attack, or renal injury occurred. Predictors of first-pass failure were higher body mass index and lack of pre-mapping, mainly in early cases, declining from 11.4% to 3.0% ( P < .001). At median follow-up of 182 days, arrhythmia-free survival was 94.1% at 3 months and 88.5% at 6 months. Conclusion In this first multicenter real-world study, TPI-guided PFA with the VLCC demonstrated high acute efficacy, no clinical strokes or TIAs, low complication rates, and favorable mid-term outcomes with structured training and standardized protocols.