- Question
- To determine whether pulmonary vein isolation is more effective than a sham procedure at reducing atrial fibrillation burden in symptomatic patients, given concerns about a large placebo effect.
- Design
- Double-blind randomized clinical trial conducted at 2 tertiary centers in the UK between January 2020 and March 2024, with 126 participants randomized. Atrial fibrillation burden was measured with an implantable loop recorder.
- Population
- Patients with symptomatic paroxysmal or persistent atrial fibrillation. Patients with long-standing persistent atrial fibrillation, prior left atrial ablation, other arrhythmias requiring ablation, a left atrium of 5.5 cm or larger, or an ejection fraction below 35% were excluded.
- Intervention
- Pulmonary vein isolation with cryoablation (n = 64).
- Control
- Sham procedure with phrenic nerve pacing (n = 62).
- Primary outcome
- Atrial fibrillation burden at 6 months, excluding a 3-month blanking period.
- Results
- The absolute mean change in atrial fibrillation burden 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 overall Atrial Fibrillation Effect on Quality of Life score at 6 months favored ablation, with an estimated difference of 18.39 points (95% CI 11.48-25.30).
- Conclusion
- Pulmonary vein isolation produced a statistically significant and clinically important reduction in atrial fibrillation burden at 6 months, with substantial improvements in symptoms and quality of life compared with a sham procedure.
- Why it matters
- As the first double-blind, sham-controlled trial of its kind, it provides evidence that the benefit of atrial fibrillation ablation is not explained by placebo effect alone, supporting its value in symptomatic patients.
Card generated automatically with AI from the abstract of the original publication and the trial registry; every figure was checked against those sources. It may contain errors: verify the data at the source before using it for clinical decisions.
Generated on October 21, 2026