The Relationship between Left Epicardial Adipose Tissue Attenuation at CT and Atrial Fibrillation: A Systematic Review and Meta-Analyses

Purpose: To perform a systematic review and meta-analysis to assess the association between epicardial adipose tissue (EAT) attenuation on CT images and atrial fibrillation (AF). Materials and Methods: The Medline, Embase, and Cochrane databases were systematically searched to identify studies published up to July 2023 that assessed the association between CT-derived EAT attenuation and AF prevalence, type, or recurrence after ablation. Meta-analyses were performed to assess the relationship between EAT attenuation and AF outcomes, expressed as the standardized mean difference (SMD). Effect sizes were considered small/ modest (around 0.2), moderate (around 0.5), or large (around 0.8). Sensitivity analyses were performed based on voltage selection. Results: Sixteen articles, encompassing 4175 patients, were included. Overall, CT EAT attenuation was not associated with AF prevalence (SMD, 0.33 [95% CI: −0.14, 0.79]; P =.17; I2 = 90%), AF type (SMD, −0.09 [95% CI: −0.37, 0.20]; P =.56; I2 = 77%), or AF recurrence (SMD, −0.01 [95% CI: −0.21, 0.19]; P =.92; I2 = 84%). However, in studies using consistent or corrected tube voltage settings, higher CT EAT attenuation was moderately associated with higher AF prevalence (SMD, 0.52 [95% CI: 0.07, 0.97]; P =.02; I2 = 81%) and modestly associated with a lower risk of AF recurrence after ablation (SMD, −0.15 [95% CI: −0.27, −0.04]; P =.01; I2 = 0%); EAT attenuation remained unassociated with AF type. Conclusion: Higher CT EAT attenuation was associated with higher AF prevalence and lower risk of AF recurrence after ablation in studies using consistent or corrected tube voltage settings, highlighting the need for methodologically uniform studies to clarify the prognostic value of EAT attenuation in AF.