Is Epicardial Adipose Tissue Associated with Atrial Fibrillation Following Cardiac Surgery? A Systematic Review and Meta-Analysis

Abstract

Background: Although epicardial adipose tissue (EAT) has been proven to be related to atrial fibrillation (AF) and post-ablation AF recurrence, the association between EAT and AF after cardiac surgery (AFACS) remains unclear. Objective: This study was a systematic review and meta-analysis that assessed the relationship between EAT and AFACS. Methods: Electronic databases were systematically searched for “atrial fibrillation” and “epicardial adipose tissue.” The analysis was stratified according to the EAT measurement into three meta-analyses as (1) total EAT volume, (2) left atrial (LA)-EAT volume, and (3) EAT thickness. Standardized mean difference (SMD) was estimated using a random effects model. Results: Eight articles with 10 studies (546 patients) were included. The meta-analysis revealed that EAT was higher in those with AFACS irrespective of the EAT measurement (total EAT volume: SMD = 0.56 mL, 95% confidence interval, CI = 0.56–1.10 mL, I2 = 0.90, P = .04; EAT thickness: SMD = 0.85 mm, 95% CI = 0.04–1.65 mm, I2 = 0.90, P = .04; LA-EAT volume: SMD = 0.57 mL, 95% CI = 0.23–0.92 mL, I2 = 0.00, P = .001). Conclusion: EAT was higher in patients with AFACS, measured either as volume or thickness.

Impact of Obesity on Atrial Fibrillation Pathogenesis and Treatment Options

“…Population studies demonstrate EAT volume is independently associated with AF occurrence, severity, and recurrence, and therefore may mediate the link between obesity and AF. 25 , 26 This association was stronger than those detected for measures of abdominal or overall adipose tissue (including BMI), suggesting a unique role for EAT. 26 Increased LA EAT volume also independently correlated with greater LA fibrosis and dilatation, which are predictors for AF.…”

“… 98 Recently, meta‐analyses have found that EAT was associated with POAF. 25 The underlying mechanism of POAF is not fully elaborated. Possible mechanisms may include pericardial inflammation, including EAT‐mediated interleukin‐6 and MCP‐1 (monocyte chemoattractant protein‐1) signaling, 99 and autonomic imbalance after cardiac surgery.…”

Redistribution of adipose tissue is associated with left atrial remodeling and dysfunction in patients with atrial fibrillation

“…Therefore, we make it clear that compared with the overall fat environment, changes in the local fat microenvironment of the heart have more critical value for the pathophysiology of AF. (2) For evaluating the change of LA in AF patients, traditional index of LA size or area has been used in most previous studies ( 11 – 13 ). Nakamori et al confirmed the correlation between EAT and LA remodeling by measuring LA diameter and volume ( 13 ).…”

“…(2) For evaluating the change of LA in AF patients, traditional index of LA size or area has been used in most previous studies ( 11 – 13 ). Nakamori et al confirmed the correlation between EAT and LA remodeling by measuring LA diameter and volume ( 13 ). In Yorguns’ study, EAT was associated with the presence of AF and the diameter of the LA ( 12 ).…”

“…Therefore, we make it clear that compared with the overall fat environment, changes in the local fat microenvironment of the heart have more critical value for the pathophysiology of AF. ( 2 EAT and LA remodeling by measuring LA diameter and volume (13). In Yorguns' study, EAT was associated with the presence of AF and the diameter of the LA (12).…”