Abstract Introduction The role of pericardial adipose tissue has been investigated in numerous studies in relation to the development of coronary artery disease (CAD) and other cardiac pathologies. Total pericardial fat (TPF) consists of epicardial adipose tissue (EAT), which is located between the myocardium and the visceral pericardium, and pericardial fat (PCF), which adheres to the parietal pericardium. The suspected mechanisms are complex and include the acceleration of inflammation and oxidative stress as well as proximity to the coronary arteries. Purpose The aim of the study was to investigate the existence of a correlation between the thickness of epicardial and pericardial adipose tissue and the presence of CAD, with the hope of using this marker in the future for risk stratification of cardiovascular disease. Methods This study enrolled 264 patients with a mean age of 59,9 +/- 10.6 years, 60,6% (160 pts) male, with cardiovascular risk factors who were investigated for suspected CAD. In all patients, the thickness of the TPF, EAT, and the PCF were measured echocardiographically during end-diastole, at the anterior atrioventricular groove. Intra- and interobserver variability was excellent (ICC 0.995-0.998 and ICC 0.992-0.995 for all three layers). Results Out of the total patients included, 54,2% (142 pts) had lesions on conventional angiography, of which 46% had hemodynamically significant lesions requiring revascularization. There were no statistically significant differences in the thickness of the three layers according to the presence of cardiovascular risk factors (diabetes mellitus, smoking, hypertension) and there was no correlation with body mass index. There were statistically significant differences in the dimensions of the pericardial adipose tissue layers between the group of patients with CAD and the group of patients without CAD (EAT 7,1 +/-2,34 vs 5,07+/-2,36 mm, PCF 9.3+/-3,01 vs 7,2+/-2,9 mm and TPF 16,7+/-3,8 vs 12.59+/-4,3 mm, p=0.001 for all cases). There were no statistically significant differences between patients who had one, two, or all three coronary arteries affected (p=0.5). There is a significant correlation between EAT and TPF (r 0.81), PCF and TPF (r 0.83), but no significant correlation between the two substrates (r 0.44). Women without CAD had a lower epicardial layer thickness than men without CAD (4,8+/-0,26 vs 5,4+/-0,29,p <0,001), but this difference did not exist in those with CAD (6.9+/-0.47 vs 7.2+/-0.24). Conclusions The study shows that echocardiographic measurement of the thickness of pericardial adipose tissue layers is a feasible method, easy to perform with good intra- and interobserver reproducibility. The data presented suggest that the thickness of the pericardial adipose tissue layers (EAT and TPF) may represent an independent risk factor for CAD and could be included in the pre-test risk assessment of patients with suspected CAD.
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