Background:
Recent data suggest that pulsed field ablation (PFA) is associated with progressively shorter procedure times, particularly with fluoroscopy-only PFA systems. The Varipulse™ PFA platform combines 3D electroanatomical mapping (EAM) with pulsed field delivery via a variable-loop circular catheter (VLCC). While its safety is increasingly reported, data on the learning curve and procedural efficiency remain limited.
Objective:
To assess the learning curve and procedural efficiency associated with a variable-loop circular catheter PFA system.
Methods:
Fifty-three patients (mean age 62 ± 10.5 years; 75.5% male; 72% paroxysmal atrial fibrillation) underwent PVI-only procedures using the Varipulse™ PFA system. The mean CHA₂DS₂-VA score was 1.8 ± 1.2, and the mean left ventricular ejection fraction (LVEF) was 57.7 ± 6.3%. Left atrial size was normal (<20 cm²) in 43.4% and mildly dilated in 22.6%. Sinus rhythm was present at the start of the procedure in 94.3%. Four experienced electrophysiologists performed all procedures. For each operator, the first three procedures were defined as the training phase and compared with subsequent post-training cases. Total procedure time, LA dwell time, fluoroscopy time, area dose product, and procedural success were analysed.
Results:
Across the total cohort, mean procedure time decreased from 86.7 ± 15.7 min in the training phase to 73.9 ± 21.0 min post-training (–14.7%; p = 0.031; Cohen’s d = 0.64).
LA dwell time showed a pronounced reduction from 76.7 ± 14.1 min to 61.6 ± 15.8 min (–19.6%; p = 0.005; d = 0.97). Fluoroscopy time decreased modestly (10.5 ± 5.8 min to 9.0 ± 4.6 min; p = 0.341), and radiation dose remained unchanged (3.41 ± 2.14 Gy·cm² vs. 3.72 ± 2.68 Gy·cm²; p = 0.676).
In operator-specific analyses, similar results were observed: LA dwell time improved significantly after the first three cases (F = 4.24, p = 0.045), while no significant differences were found for total procedure time, fluoroscopy time, or radiation dose.
In multivariate analysis, learning curve significantly affected LA dwell time (F = 6.55; p = 0.014; η² = 0.141), whereas operator and BMI influenced radiation exposure but not procedural duration. Acute PVI was achieved in all patients without RF-touch-up.
Conclusion:
The learning curve for the Varipulse™ PFA system is short. Procedural efficiency, particularly in LA dwell time, improves after only a few cases, while radiation parameters did not decline.
