Abstract 533: Increased Epicardial Adipose Tissue as a Predictor of Coronary Low Density Plaque, Using 64-multidetector Computed Tomography
Background: Some studies suggest that the epicardial adipose tissue surrounding coronary arteries, which has metabolic activity, and produces hormones and cytokines, may be associated with coronary artery disease. However, the relationship between the epicardial adipose tissue and plaque vulnerability remains unclear. We examine whether the increased epicardial fat volume (EFV) is related to coronary plaque vulnerability.
Methods and Results: We enrolled 258 consecutive patients (age: 66 ± 11: 65% men) who underwent 64-multidetector computed tomography (CT) for coronary evaluation. EFV was calculated as the sum of cross-sectional images 1cm thick from the atrial appendage to the apex. A density range from −30 to −250 Hounsfield Units (HU) was used to isolate adipose tissue. Patients were divided by EFV (cut off value: 100ml) into two subgroups: a normal EFV group and an increased EFV group. The cut off value was determined according to a past reported study and necropsy report. The presence of coronary low density plaque (LDP: minimum CT density <40 HU) was used as an indicator of lipid-rich plaque. The EFV ranged from 26.2 to 307.8 ml (mean 125.7 ± 45.7 ml), and was significantly higher in patients with LDP than those without (n = 125; 116.7 ± 41.1 ml vs. n = 133; 132.8 ± 45.1 ml, P = 0.004). In a univariate analysis, the presence of LDP was correlated with gender (odds ratio: OR [95% confidential interval: 95% CI] 2.32 [1.38 –3.60], P = 0.002), diabetes mellitus (2.91 [1.71–5.05], P = 0.0001), smoking (2.27 [1.25–3.86], P = 0.002), hypertension (1.99 [1.18 –3.40], P = 0.01), LDL/HDL ratio (1.82 [1.11–2.99], P = 0.018) and increased EFV (2.90 [1.70 –5.04], P = 0.0005). After adjustment for age, gender, and the traditional cardiovascular risk factors, the increased EFV remained as an independent predictor for the presence of LDP (1.83 [1.02–3.51], P = 0.04).
Conclusions: Quantification of EFV is related to coronary plaque vulnerability and is thought to be a new predictor to identify patients prone to acute coronary syndrome.