Pulsed Field Ablation as Initial Therapy for Persistent Atrial Fibrillation

BACKGROUND: Guidelines recommend a trial of antiarrhythmic drugs before catheter ablation for persistent atrial fibrillation. Whether pulsed field ablation (PFA) may be a preferred initial treatment is unclear. METHODS: We conducted an international, randomized trial involving patients with previously untreated persistent atrial fibrillation. The patients were randomly assigned in a 2:1 ratio to receive PFA performed with a pentaspline catheter or to receive antiarrhythmic-drug therapy. An additional group of patients (PFA-assigned) underwent PFA for the analysis of the primary safety end point alone. All the patients received an insertable cardiac monitor. The primary effectiveness end point was the short-term and long-term success of treatment through 12 months. Short-term success was defined as procedural success in the PFA group and the absence of ablation during the blanking period (90 days after treatment initiation) in the antiarrhythmic-drug group. Long-term success was defined as freedom from recurrence of atrial arrhythmias, repeat ablation, or need for antiarrhythmic drugs from 90 days through 12 months (in the PFA group) and freedom from amiodarone use at any time. The primary safety end point was device- and procedure-related serious adverse events. RESULTS: At 12 months, treatment success was observed in 128 of 207 patients (Kaplan-Meier estimate, 56%; 95% confidence interval [CI], 48 to 63) in the PFA group and in 40 of 103 patients (Kaplan-Meier estimate, 30%; 95% CI, 21 to 40) in the antiarrhythmic-drug group (hazard ratio for composite treatment failure [a lack of short- and long-term success], 0.46; 95% CI, 0.33 to 0.65; P