title: Association between left atrial size and atrial fibrillation recurrence after single circumferential pulmonary vein isolation: a systematic review and meta-analysis of observational studies.
abstract: OBJECTIVE
  Left atrial (LA) enlargement is associated with atrial fibrillation (AF). However, it is controversial whether dilated atrium can predict post-ablation AF recurrence. We undertook a systematic review and meta-analysis to analyse the association between LA diameter and AF recurrence after single circumferential pulmonary vein isolation (CPVI) and explore the potential mechanism.
  
  
  RESULTS
  Electronic databases and bibliographies of retrieved studies were searched. The anteroposterior diameters of LA were available in all included studies, which were measured at end-systole by M-mode transthoracic echocardiography. Subgroup analysis was conducted based on the duration of follow-up. Weighted mean difference (WMD) and 95% confidence interval (CI) were calculated using random-effect or fixed-effect model, depending on statistical heterogeneity. Twenty-two studies with a total of 3750 individuals met the inclusion criteria. The summary WMD of LA diameter between patients with and without recurrence was 1.87 mm (95% CI 1.26-2.48, P< 0.001). Meta-regression analysis of the 22 studies indicated that study design, duration of follow-up, and measurement of asymptomatic recurrences were significant sources of heterogeneity. Sensitivity analysis suggested that the difference in LA diameter between patients with and without recurrences persisted regardless of the duration of follow-up.
  
  
  CONCLUSIONS
  Dilated LA significantly increases the risk of AF recurrence after single CPVI. This is especially applicable to the patients with long-term follow-up.
authors: Department of Cardiology, Shanghai Tenth People's Hospital,  Tongji University School of Medicine, 301 Middle Yanchang Road, Shanghai 200072,  China.
authors: Jianhui
authors: J
authors: Zhuang
authors: Yi
authors: Y
authors: Wang
authors: Kai
authors: K
authors: Tang
authors: Xiankai
authors: X
authors: Li
authors: Wenhui
authors: W
authors: Peng
authors: Chun
authors: C
authors: Liang
authors: Yawei
authors: Y
authors: Xu
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D006332:Cardiomegaly / Q000453:epidemiology* / Q000473:pathology*; D017115:Catheter Ablation / Q000379:methods*; D006325:Heart Atria / Q000473:pathology; D006801:Humans; D011667:Pulmonary Veins / Q000601:surgery*; D012307:Risk Factors; D055502:Secondary Prevention