Is epicardial fat tissue associated with atrial fibrillation recurrence after ablation? A systematic review and meta-analysis

Introduction: Although an undoubted association between epicardial fat tissue (EFT) and atrial fibrillation (AF) has been recently approved, the association between EFT and post-ablation AF recurrence is not evident yet. This study aimed to assess the association between EFT and AF recurrence after ablation. Methods: The present study was a systematic review and meta-analysis using related literature available in electronic databases until July 2018 via “atrial fibrillation” and “epicardial fat” as the main keywords. Considering the different methods of EFT measurement, three different pooled meta-analyses were conducted in this study including: 1) comparison of total EFT volume, 2) left atrium (LA)-EFT volume, and 3) EFT thickness between two groups with and without AF recurrence estimating standardized mean difference (SMD) through a random and non-random effect meta-analysis. Statistical analysis was also performed using Comprehensive Meta-analysis (CMA) Software. Results: Following a search into a total number of 518 articles, the findings of 12 studies published in 10 articles were enrolled in this meta-analysis. Accordingly, the results of meta-analysis showed that LA-EFT and total EFT volumes were higher in recurrent subjects (LA-EFT: SMD = 0.862 ml; I2 = 0.00, 95% confidence interval (CI) = 0.567–1.156; total EFT: SMD = 1.017 ml, I2 = 0.00, 95% CI = 0.748–1.286). Besides, a significant higher EFT thickness in patients with AF recurrence compared to those with no AF recurrence was observed (SMD = 0.808 mm, I2 = 91.07, 95% CI = 0.215–1401). Conclusion: The total EFT and LA-EFT volumes, as well as EFT thickness, seemed to be associated with AF recurrence in patients undergoing AF ablation. Keywords: Epicardial fat, Adipose tissue, Atrial fibrillation, Recurrence, Risk assessment, Prognosis