Pulsed Field Ablation Versus Sham to Treat Atrial Fibrillation: The PFA-SHAM Randomized Clinical Trial

BACKGROUND: Catheter ablation for atrial fibrillation (AF) is one of the most common cardiovascular procedures being performed worldwide. Despite the large body of evidence of its effectiveness, with a single exception, prior ablation studies were largely unblinded trials. Accordingly, residual concerns remained about placebo effects, both for AF recurrence and, in particular, on subjective outcomes such as quality of life or anxiety. Here, we compared pulsed field ablation (PFA) with a sham procedure to treat patients with symptomatic AF. METHODS: This prospective, sham-controlled, single-blind, randomized clinical trial with blinded end-point assessment enrolled patients with AF that was highly symptomatic (Atrial Fibrillation Effect on Quality-of-Life score <50). Patients were assigned 1:1 to PFA or a sham procedure. All participants received implantable cardiac monitors for continuous rhythm monitoring during follow-up. The 6-month co-primary outcomes were (1) time to first recurrence of atrial tachyarrhythmia and (2) changes from baseline in Atrial Fibrillation Effect on Quality-of-Life scores compared between groups. Secondary outcomes were AF burden and psychological distress (assessed by the Hospital Anxiety and Depression Scale [HADS]). RESULTS: Patients (n=60) were randomized to PFA or sham. At 6 months, the first co-primary end point of AF recurrence was met in 2 patients (6.7%) who underwent PFA and 25 patients (83.3%) who underwent sham (posterior hazard ratio, 19.6 [95% bayesian credible intervals, 6.7-76.9]; posterior probability of superiority >0.99). For the second co-primary end point, Atrial Fibrillation Effect on Quality-of-Life scores showed greater improvement from baseline with PFA than sham (improved by 43.9+18.1 points versus 11.3+27.9 points; posterior median difference, 32.6 [95% bayesian credible interval, 20.2-44.9]; posterior probability of superiority >0.99). AF burden at 6 months was significantly lower in the PFA than the sham group (0 [0-0] versus 0.43 [0.04-3.47]; between group median difference, -0.39 [95% credible interval, -2.5 to -0.1], posterior probability of superiority >0.99). The Hospital Anxiety and Depression Scale score changed by -4 points (-7.8 to -2.0) with PFA and by -0.5 (-4.5 to 1.0) with sham (group median difference, -3.5 [95% credible interval, -6.0 to -1.0]; posterior probability of superiority >0.99). CONCLUSIONS: In patients with AF, PFA was superior to sham in reducing arrhythmia recurrences and burden and improving quality of life and AF-associated psychological distress. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05717725.