Pulmonary Vein Isolation vs Sham Intervention in Symptomatic Atrial Fibrillation
Rajdip Dulai, Neil Sulke, Nick Freemantle, Pier D. Lambiase, David Farwell, Neil T. Srinivasan, Stuart Tan, Nikhil Patel, Adam Graham, Rick A. Veasey
Abstract
Importance: There are concerns that pulmonary vein isolation for atrial fibrillation may have a profound placebo effect, but no double-blind randomized clinical trials have been conducted. Objective: To determine whether pulmonary vein isolation is more effective than a sham procedure for improving outcomes in atrial fibrillation. Design, Setting, and Participants: Double-blind randomized clinical trial conducted at 2 tertiary centers in the UK between January 2020 and March 2024 among patients with symptomatic paroxysmal or persistent atrial fibrillation. Major exclusion criteria included long-standing persistent atrial fibrillation, prior left atrium ablation, other arrhythmias requiring ablative therapy, a left atrium of 5.5 cm or larger, and ejection fraction of less than 35%. Intervention: Participants were randomly assigned to receive pulmonary vein isolation with cryoablation (n = 64) or a sham procedure with phrenic nerve pacing (n = 62). Main Outcomes and Measures: The primary end point was atrial fibrillation burden at 6 months, excluding a 3-month blanking period. Secondary outcomes included quality-of-life measures, time to events, and safety. Atrial fibrillation burden was measured by an implantable loop recorder. Results: A total of 126 participants were randomized (mean age, 66.8 years; 89 men [70.63%]; 20.63% with paroxysmal atrial fibrillation). The absolute mean atrial fibrillation burden change from baseline to 6 months was 60.31% in the ablation group and 35.0% in the sham group (geometric mean difference, 0.25; 95% CI, 0.15-0.42; P < .001). The estimated difference in the overall Atrial Fibrillation Effect on Quality of Life score at 6 months, favoring catheter ablation, was 18.39 points (95% CI, 11.48-25.30 points). The Short Form 36 general health score also improved substantially more with ablation, with an estimated difference of 9.27 points at 6 months (95% CI, 3.78-14.76 points). Conclusions and Relevance: Pulmonary vein isolation resulted in a statistically significant and clinically important decrease in atrial fibrillation burden at 6 months, with substantial improvements in symptoms and quality of life, compared with a sham procedure. Trial Registration: ClinicalTrials.gov Identifier: NCT04272762.