Relationships of pericoronary and epicardial fat measurements in male and female patients with and without coronary artery disease

Introduction: Although pericoronary adipose tissue (PCAT) is a component of the epicardial adipose tissue (EAT) depot, they may have different associations to coronary artery disease (CAD). We explored relationships between pericoronary adipose tissue mean attenuation (PCAT(MA)) and EAT measurements in coronary CT angiography (CCTA) in patients with and without CAD.Material and methods: CCTA scans of 185 non-CAD and 81 CAD patients (86.4% >50% stenosis) were included and retrospectively analyzed. PCAT(MA) and EAT density/volume were measured and analyzed by sex, including associations with age, risk factors and tube voltage using linear regression models.Results: In non-CAD and CAD, mean PCAT(MA) and EAT volume were higher in men than in women (non-CAD: -92.5 +/- 10.6HU vs -96.2 +/- 8.4HU, and 174.4 +/- 69.1 cm(3) vs 124.1 +/- 57.3 cm(3); CAD: -92.2 +/- 9.0HU vs -97.4 +/- 9.7HU, and 193.6 +/- 62.5 cm(3) vs 148.5 +/- 50.5 cm(3) (p < 0.05)). EAT density was slightly lower in men than women in non-CAD (-96.4 +/- 6.3HU vs -94.4 +/- 5.5HU (p < 0.05)), and similar in CAD (-98.2 +/- 5.2HU vs 98.2 +/- 6.4HU). There was strong correlation between PCAT(MA) and EAT density (non-CAD: r = 0.725, p < 0.001, CAD: r = 0.686, p < 0.001) but no correlation between PCAT(MA) and EAT volume (non-CAD: r = 0.018, p = 0.81, CAD: r = -0.055, p = 0.63). A weak inverse association was found between EAT density and EAT volume (non-CAD: r = -0.244, p < 0.001, CAD: r = -0.263, p = 0.02). In linear regression models, EAT density was significantly associated with PCAT(MA) in both non-CAD and CAD patients independent of risk factors and tube voltage.Conclusion: In CAD and non-CAD patients, EAT density, but not EAT volume, showed significant associations with PCAT(MA). Compared to women, men had higher PCAT(MA) and EAT volume independently of disease status, but similar or slightly lower EAT density. Differences in trends and relations of PCAT(MA) and EAT by sex could indicate that personalized interpretation and thresholding is needed.