Epicardial Adipose Tissue Thickness as a Predictor of Coronary Artery Disease Severity

Abstract

Introduction: Epicardial adipose tissue (EAT) is a metabolically active visceral fat depot that may locally influence coronary atherosclerosis. Whether EAT thickness measured by echocardiography predicts coronary artery disease (CAD) severity beyond traditional risk factors remains unclear.
Methods: A systematic review of cross-sectional and prospective studies using transthoracic echocardiography to measure EAT at end-systole. Inclusion: adults undergoing coronary angiography. Exclusion: prior revascularization. Primary endpoint: moderate-to-severe CAD (≥50% stenosis in ≥1 vessel) or SYNTAX score.
Results: 24 studies (n=8,432 patients) met criteria. Pooled EAT thickness was significantly higher in patients with vs. without CAD (mean difference 2.8 mm, 95%CI 2.1–3.5). For predicting significant CAD, optimal cutoff ranged 5.5–7.0 mm with sensitivity 70% and specificity 68%. Each 1 mm increase in EAT was associated with a 23% higher odds of multivessel disease (OR 1.23, 1.12–1.35). Correlation with SYNTAX score: r=0.54 (p<0.001).
Discussion: EAT may exert paracrine effects through secretion of pro-inflammatory cytokines (IL-6, TNF-α) and adipokines. Limitations include measurement variability (different cardiac cycles, training) and lack of standardized protocols. Most studies from single centers, predominantly Asian populations.
Conclusions: Increased EAT thickness is associated with presence and severity of coronary artery disease. Echocardiographic EAT assessment is a simple, low-cost adjunctive risk marker, but standardization is needed before clinical implementation.