Abstract 12257: The Relationship Between Histological Features of Epicardial Adipose Tissue and Aortic Valve Calcification Assessed on Computed Tomography

Abstract

Background: It has been hypothesized that epicardial adipose tissue (EAT) biologically contributes to the pathogenesis of cardiac diseases. However, it remains unclear how EAT correlates with the progression of aortic valve calcification (AVC). We evaluated if histological features of EAT are specifically related to AVC assessed on computed tomography (CT). Methods: We enrolled 35 patients undergoing cardiac CT examination before elective cardiac surgery (coronary artery bypass graft [CABG] and/or cardiac valve surgery), in which AVC was detected on CT. Each patient was evaluated with EAT volume, coronary calcium score (CCS), AVC score, and the presence of high-risk coronary plaque (HRP) on CT. During each cardiac surgery, histological samples for immunohistochemistry were obtained from EATs adjacent to the left anterior descending and right coronary arteries. Each patient was assessed with the numbers of CD-68 + and CD-11c + individual macrophages and osteocalcin + individual cells in a total of 6 random high-power fields (x400) of EAT samples. Results: In the histological findings of EAT, osteocalcin + cells showed a weak correlation with CD-68 + macrophages ( r = 0.40, p = 0.016) and a moderate correlation with CD-11c + macrophages ( r = 0.60, p = 0.0001). The AVC score on CT correlated with CD-11c + macrophages and osteocalcin + cells in EAT (Fig 1), whereas CCS had no correlation with such histological findings. On multivariate analysis adjusted for age, sex, CABG vs. non-CABG, EAT volume, CCS, and the presence of HRP, the AVC score independently correlated with increased CD-11c + macrophages (β = 0.58; p = 0.0036) and osteocalcin + cells (β = 0.59; p = 0.0021) in EAT. Fig 2 shows representative cases with different levels of AVC and EAT histology. Conclusions: The inflammatory and osteogenic activity in EAT significantly correlate with the progression of AVC, which may indicate a specific contribution of EAT to aortic valve degeneration through biological activities.