title: Efficacy of catheter ablation for persistent atrial fibrillation: a systematic review and meta-analysis of evidence from randomized and nonrandomized controlled trials.
abstract: 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.
  
  
  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.
authors.affiliation: From the Institute of Cardiovascular Medicine and Science, Liverpool and London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Cardiology, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom (G.J.W., M.D., D.G.); National Heart and Lung Institute, Imperial College London, London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom (L.J.B.); and Department of Cardiology, Royal Brompton Hospital, London, United Kingdom (S.P., T.W.).
authors.forename: Gareth J
authors.initials: GJ
authors.lastname: Wynn
authors.affiliation: From the Institute of Cardiovascular Medicine and Science, Liverpool and London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Cardiology, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom (G.J.W., M.D., D.G.); National Heart and Lung Institute, Imperial College London, London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom (L.J.B.); and Department of Cardiology, Royal Brompton Hospital, London, United Kingdom (S.P., T.W.).
authors.forename: Moloy
authors.initials: M
authors.lastname: Das
authors.affiliation: From the Institute of Cardiovascular Medicine and Science, Liverpool and London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Cardiology, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom (G.J.W., M.D., D.G.); National Heart and Lung Institute, Imperial College London, London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom (L.J.B.); and Department of Cardiology, Royal Brompton Hospital, London, United Kingdom (S.P., T.W.).
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Bonnett
authors.affiliation: From the Institute of Cardiovascular Medicine and Science, Liverpool and London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Cardiology, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom (G.J.W., M.D., D.G.); National Heart and Lung Institute, Imperial College London, London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom (L.J.B.); and Department of Cardiology, Royal Brompton Hospital, London, United Kingdom (S.P., T.W.).
authors.forename: Sandeep
authors.initials: S
authors.lastname: Panikker
authors.affiliation: From the Institute of Cardiovascular Medicine and Science, Liverpool and London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Cardiology, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom (G.J.W., M.D., D.G.); National Heart and Lung Institute, Imperial College London, London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom (L.J.B.); and Department of Cardiology, Royal Brompton Hospital, London, United Kingdom (S.P., T.W.).
authors.forename: Tom
authors.initials: T
authors.lastname: Wong
authors.affiliation: From the Institute of Cardiovascular Medicine and Science, Liverpool and London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Cardiology, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom (G.J.W., M.D., D.G.); National Heart and Lung Institute, Imperial College London, London, United Kingdom (G.J.W., M.D., S.P., T.W., D.G.); Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom (L.J.B.); and Department of Cardiology, Royal Brompton Hospital, London, United Kingdom (S.P., T.W.). Dhiraj.gupta@lhch.nhs.uk.
authors.forename: Dhiraj
authors.initials: D
authors.lastname: Gupta
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods; D018572:Disease-Free Survival; D006325:Heart Atria / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D016017:Odds Ratio; D011667:Pulmonary Veins / Q000503:physiopathology / Q000601:surgery; D016032:Randomized Controlled Trials as Topic; D012008:Recurrence; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents
keywords: atrial fibrillation; meta-analysis