Pulsed Field or Cryoballoon Ablation for Paroxysmal Atrial Fibrillation

BACKGROUND: Pulmonary-vein isolation is an effective treatment for paroxysmal atrial fibrillation. Pulsed field ablation (PFA) is a nonthermal ablation method with few adverse effects beyond the myocardium. Data are lacking on outcomes after PFA as compared with cryoballoon ablation as assessed with continuous rhythm monitoring. METHODS: In this randomized noninferiority trial in Switzerland, we randomly assigned patients with symptomatic paroxysmal atrial fibrillation in a 1:1 ratio to undergo PFA or cryoablation. All the patients received an implantable cardiac monitor to detect atrial tachyarrhythmias. The primary end point was the first recurrence of an atrial tachyarrhythmia between day 91 and day 365 after ablation. We assessed noninferiority using a margin of 20 percentage points for the difference in the cumulative incidence of recurrence. The safety end point was a composite of procedure-related complications. RESULTS: A total of 105 patients were assigned to undergo PFA, and 105 were assigned to undergo cryoablation. A recurrence of atrial tachyarrhythmia was observed between day 91 and day 365 in 39 patients in the PFA group and in 53 patients in the cryoablation group (Kaplan-Meier cumulative incidence, 37.1% and 50.7%, respectively; between-group difference, -13.6 percentage points; 95% confidence interval, -26.9 to -0.3; P<0.001 for noninferiority, P = 0.046 for superiority). The safety end point occurred in 1 patient (1.0%) with PFA and in 2 patients (1.9%) with cryoablation. CONCLUSIONS: Among patients with symptomatic paroxysmal atrial fibrillation, PFA was noninferior to cryoballoon ablation with respect to the incidence of a first recurrence of atrial tachyarrhythmia, as assessed by continuous rhythm monitoring. (Funded by Inselspital and others; SINGLE SHOT CHAMPION ClinicalTrials.gov number, NCT05534581.).