Efficacy of Catheter Ablation for Persistent Atrial Fibrillation: A Systematic Review and Meta-Analysis of Evidence From Randomized and Nonrandomized Controlled Trials

Background—Catheter ablation (CA) is commonly performed for persistent atrial fibrillation, but few high-quality randomized controlled trials (RCTs) exist, leading to funding restrictions being proposed in several countries. We performed a random-effects meta-analysis of RCTs and non-RCTs to assess the efficacy of CA for persistent atrial fibrillation. Methods and Results—We systematically searched PubMed, EMBASE, CENTRAL, OpenGrey, and clinicaltrials.gov for RCTs and non-RCTs reporting clinical outcomes after CA for persistent atrial fibrillation. Forty-six eligible studies were identified containing 3819 patients. After a single procedure, CA significantly reduced the risk of recurrent atrial fibrillation compared with medical therapy (odds ratio [OR], 0.32; 95% confidence interval [CI], 0.20–0.53; P<0.001). Outcomes were better if the pulmonary veins were encircled (OR, 0.26; 95% CI, 0.09–0.74; P=0.01), and electrical isolation reduced AF recurrence compared with purely anatomic encirclement (OR, 0.33; 95% CI, 0.13–0.86; P=0.02). Linear ablation within the left atrium (OR, 0.22; 95% CI, 0.10–0.49; P<0.001), but not complex fractionated atrial electrogram ablation (OR, 0.64; 95% CI, 0.35–1.18; P=0.15), significantly reduced AF recurrence. Results were not improved by performing more extensive linear lesion sets (OR, 0.77; 95% CI, 0.41–1.43; P=0.40) or from biatrial ablation (OR, 0.62; 95% CI, 0.31–1.24; P=0.17). Where data were available, the relative benefits seen held true both after a single or multiple procedure(s). Sensitivity analyses showed that inclusion of non-RCTs increased statistical power without biasing the calculated effect sizes. Conclusions—For patients with persistent atrial fibrillation, CA achieves significantly greater freedom from recurrent atrial fibrillation compared with medical therapy. The most efficacious strategy is likely to combine isolation of the pulmonary veins with limited linear ablation within the left atrium.