Pericardial fat volume as a predictor of atherosclerosis, stenosis severity and plaque composition in symptomatic and asymptomatic populations - a cardiac CT angiography study

Abstract

Introduction: Coronary CT angiography (CCTA) can provide comprehensive information of the coronary arteries, including the identification of coronary plaques, determination of stenosis severity and morphological characterization of plaques with regard to the presence or absence of calcification – all of which have been linked to the pathogenesis of coronary artery disease (CAD). It is also possible to calculate the pericardial fat volume (PFV) using CCTA; however the relationship of PFV to CAD has been controversial. The aim of this study was to evaluate the relationship between PFV and these indicators of CAD in asymptomatic and symptomatic population-based cohorts. Method and Results: The CCTA scans of asymptomatic (383) people and symptomatic (549) patients were examined. The symptomatic patients were part of the “Cardiac cT in the treatment of acute Chest pain” (CATCH) trial and were admitted on suspicion of acute coronary syndrome with a normal electrocardiogram and troponins. The asymptomatic cohort was taken randomly from the Copenhagen General Population Study. Measurements were made on the PFV, stenosis grading, plaque characteristics, and coronary artery calcium (CAC) scores. Relations between PFV and the indicators of CAD were assessed using logistic regression. In the symptomatic population, 59% of the patients had atherosclerosis present, compared to 73% in the asymptomatic population. Symptomatic patients with atherosclerosis had a significantly higher mean PFV (142.96 mL) compared to those without (111.22 mL, P<0.001). A significant difference was also detected in the asymptomatic population (199.32 mL vs. 171.5 mL, P=0.079). When adjusting for age, gender, and BMI, a larger PFV was significantly associated with atherosclerosis in symptomatic patients (P=0.044), but not asymptomatic patients (P=0.358). PFV was not a predictor of significant coronary artery stenosis (≥70%) in either population, although in symptomatic patients, increased PFV was independently associated with the presence of noncalcified plaques (P=0.032). There was no relationship between PFV and CAC scores in symptomatic or asymptomatic populations (P=0.403 and P=0.292 respectively). Conclusion: These findings support the hypothesis that PFV contributes to the presence of coronary atherosclerosis and also can indicate the presence of non-calcified plaques, but only for symptomatic patients. However, PFV cannot predict the degree of stenosis.