Catheter Ablation Versus Sham for Symptomatic Atrial Fibrillation: A Systematic Review and Bayesian Meta-Analysis of Randomized Trials

Background Catheter ablation reduces atrial fibrillation (AF) recurrence and improves symptoms and quality of life (QoL), but sham-controlled trials have reported discordant results. Objective To synthesise sham-controlled trials of AF ablation and identify why QoL results differ. Methods We searched databases and registries for randomized trials of catheter ablation versus sham in symptomatic AF. The primary outcome was the between-group difference in Atrial Fibrillation Effect on Quality-of-Life (AFEQT) score, pooled using a Bayesian random-effects model. Certainty was rated with the Grading of Recommendations Assessment, Development and Evaluation. Results Four trials (468 patients) were eligible; three (448 patients) were pooled. Ablation improved AFEQT relative to sham by 13.5 points (95% credible interval [CrI] 1.6 to 26.9), with a posterior probability of benefit 0.98, of exceeding the 5-point minimal clinically important difference 0.94, and by 12.9 points (-0.4 to 27.1; probability 0.97 and 0.91) with PVI-SHAM-AF's primary estimator. Heterogeneity (τ 8.2 points, I 2 85.3%) was largely attributed to PVI-SHAM-AF, which differed from the other trials in symptom severity, rhythm monitoring and assessment of blinding; without it, the difference was 18.9 points (6.7 to 31.4). Ablation reduced AF recurrence in every trial (pooled risk ratio 0.49, CrI 0.17-0.89). Certainty was moderate for AF burden and recurrence and low for QoL. Conclusion Compared with sham embedded in active rhythm control, catheter ablation reduces AF recurrence and burden and has a high probability of clinically important QoL benefit, although its magnitude remains uncertain. Trials differ in population, monitoring, and estimator, not direction of effect.