Could a high epicardial adipose tissue volume increase the ability of the calcium score to discriminate cardiovascular events in an asymptomatic population?

Abstract

Abstract Background Evidence indicates that an elevated calcium score (CAC) is a risk marker for subclinical atherosclerosis and cardiovascular (CV) events in the asymptomatic population. Recent research has shown that high epicardial adipose tissue (EAT) volume is associated with coronary calcification and CV events It is unknown whether the association between the two risk markers improved the ability to predict CV events. Objective Evaluate whether a high EAT volume added to the CAC score improves the predictive ability to discriminate CV events in an asymptomatic population without apparent cardiovascular disease (CVD). Methods A prospective cohort was performed with 1024 participants (mean age 51.6±8.2 years, 75.6% male) selected from controls of the GENEMACOR Study. CAC score was performed by cardiac computed tomography, and CAC severity was reported as an absolute Agatston unit stratified for age and sex- percentile (according to the Hoff Nomogram). EAT volume was measured with a quantitative semi-automated procedure using a postprocessing workstation-TeraRecon Aquarius Workstation (version 4.4.7, TeraRecon, Inc., San Mateo, CA, USA). We evaluated the discriminative ability of the CAC model without (model 1) and with EAT volume (model 2) using the ROC curve along with respective AUC and Harrel C statistics. Categorical free Net Reclassification Improvement (cfNRI) and Integrated Discrimination Index (IDI) reclassified patients. Results CAC model showed a C Index of 0.733 (95%CI 0.633-0.833), which increased to 0.756 (95%CI 0.638-0.874) when EAT volume was included in the model. The difference between the two C indexes was significant (delta C statistic=0.023; p=0.020). CfNRI reclassified 63.6% of the population (p=0.0003), and IDI improved the discrimination when EAT was included in CAC model (IDI=0.011; p=0.015). Conclusion Our findings displayed that the CAC score associated with a high EAT volume increased the predictive and discriminative ability to event occurrence. Improving the identification of high-risk patients at a subclinical stage could avoid atherosclerosis progression and events occurrence through preventive measures.