Increased Epicardial, Pericardial, and Subcutaneous Adipose Tissue Is Associated with the Presence and Severity of Coronary Artery Calcium

Rationale and Objectives: Epicardial adipose tissue (EAT), pericardial adipose tissue (PAT), and subcutaneous adipose tissue (SAT) are mediators of metabolic risk and may be involved in the pathogenesis of coronary artery disease. The aim of this study was to investigate the association of visceral and subcutaneous fat depots with the presence and severity of coronary artery calcium (CAC) in asymptomatic individuals. Materials and Methods: One hundred eleven consecutive subjects underwent CAC assessment, and their Framingham risk scores were measured. EAT, total thoracic adipose tissue, and SAT volumes were measured from slice level 15 mm above to 30 mm below the ostium of the left main coronary artery. PAT was calculated as thoracic adipose tissue - EAT. SAT was defined as the volume of fat depot anterior to the sternum and posterior to the vertebra. CAC was defined as 0, 1 to 100, 101 to 400, or >= 400. Relative risk regression analysis was used to assess the association between fat depots and CAC. Results: There were modest correlations between EAT (r = 0.58), PAT (r = 0.47), SAT (r = 0.34), and CAC (P < .01). EAT, PAT, and SAT increased proportionally with the severity of CAC in both genders (P < .05). After adjustment for cardiovascular risk factors and body mass index, the relative risks for each standard deviation increase in EAT, PAT, and SAT were 3.3 (95% confidence interval, 1.9-5.6), 2.7 (95% confidence interval, 1.6-3.9), and 2.6 (95% confidence interval, 1.5-4.4) for CAC >= 100 compared to CAC 0, respectively (P < .05). The area under the receiver-operating characteristic curve to predict CAC >= 100 was higher in each fat depot compared to Framingham risk score, and addition of fat depots to Framingham risk score provided maximum prognostication value to detect CAC >= 100. Conclusions: Increased EAT, PAT, and SAT are associated with the severity of CAC independent of risk factors.