Abstract
Introduction: Identifying markers to discriminate high and low-risk individuals better is essential. Coronary Calcium Score (CAC) is an established marker of subclinical atherosclerosis. Epicardial Adipose Tissue (EAT), a new imaging biomarker, has shown considerable interest in the scientific community.
Purpose: Study the impact of EAT volume in discrimination and reclassification of cardiovascular events when added to CAC score. Investigate whether EAT volume is a good prognosis marker in an asymptomatic population.
Methods: A cohort of 1024 individuals without coronary disease were selected and followed prospectively during an extended period. CAC score was evaluated by cardiac tomography. Quantification of EAT was performed through a semi-automated technique (TeraRecon Aquarius Workstation). Pearson’s or Spearman’s correlations identified EAT-associated parameters. Harrel C-statistics assessed the discriminative ability for events. Categorical free Net Reclassification Improvement (cfNRI) and Integrated Discrimination Index (IDI) reclassified the individuals. Kaplan-Meier evaluated cardiovascular disease prognosis, and Cox regression identified variables independently associated with cardiovascular events.
Results: EAT volume was significantly correlated with age, body mass index, non-high-density lipoprotein (HDL) cholesterol, triglycerides, systolic and diastolic blood pressure, and inversely with HDL cholesterol. CAC score and EAT had a C-Statistic of 0.737 (0.651 - 0.823) and 0.662 (0.564-0.760), respectively. When EAT was added to CAC, it increased to 0.777 (0.681 - 0.873) and 60% of the participants were better reclassified (NRI=60%). Higher EAT volume displayed the worst prognosis (p=0.006) and was associated, independently, with cardiovascular events, even after adjusting for risk factors and CAC score (p=0.021).
Conclusions: EAT may be an essential imaging marker of subclinical atherosclerosis and a potential therapeutic target for primary prevention. Reducing EAT volume with adequate measures (physical exercise, proper diet, pharmacological interventions) could decrease atherosclerosis and improve outcomes.