Cardiac computed tomography-derived epicardial fat volume and attenuation independently distinguish patients with and without myocardial infarction

Abstract

Background and objectiveEpicardial adipose tissue (EAT) volume is associated with coronary plaque burden and adverse events. We aimed to determine, whether CT-derived EAT attenuation in addition to EAT volume distinguishes patients with and without myocardial infarction.Methods and resultsIn 94 patients with confirmed or suspected coronary artery disease (aged 66.9±14.7years, 61%male) undergoing cardiac CT imaging as part of clinical workup, EAT volume was retrospectively quantified from non-contrast cardiac CT by delineation of the pericardium in axial images. Mean attenuation of all pixels from EAT volume was calculated. Patients with type-I myocardial infarction (n = 28) had higher EAT volume (132.9 ± 111.9ml vs. 109.7 ± 94.6ml, p = 0.07) and CT-attenuation (-86.8 ± 5.8HU vs. -89.0 ± 3.7HU, p = 0.03) than patients without type-I myocardial infarction, while EAT volume and attenuation were only modestly inversely correlated (r = -0.24, p = 0.02). EAT volume increased per standard deviation of age (18.2 [6.2–30.2] ml, p = 0.003), BMI (29.3 [18.4–40.2] ml, p<0.0001), and with presence of diabetes (44.5 [16.7–72.3] ml, p = 0.0002), while attenuation was higher in patients with lipid-lowering therapy (2.34 [0.08–4.61] HU, p = 0.04). In a model containing volume and attenuation, both measures of EAT were independently associated with the occurrence of type-I myocardial infarction (OR [95% CI]: 1.79 [1.10–2.94], p = 0.02 for volume, 2.04 [1.18–3.53], p = 0.01 for attenuation). Effect sizes remained stable for EAT attenuation after adjustment for risk factors (1.44 [0.77–2.68], p = 0.26 for volume; 1.93 [1.11–3.39], p = 0.02 for attenuation).ConclusionCT-derived EAT attenuation, in addition to volume, distinguishes patients with vs. without myocardial infarction and is increased in patients with lipid-lowering therapy. Our results suggest that assessment of EAT attenuation could render complementary information to EAT volume regarding coronary risk burden.

The Natural history of Epicardial Adipose Tissue Volume and Attenuation: A long-term prospective cohort follow-up study

“…EAT volume, and more recently attenuation have been increasingly investigated in the literature for associations with cardiac disease 8,[11][12][13][14][15] . Several studies have demonstrated significant cross-sectional relationships www.nature.com/scientificreports www.nature.com/scientificreports/ between EAT and cardiac disease, however a lack of longitudinal data prevents understanding of what therapies or targets may be a modulating factor for EAT.…”

Associations of cardiovascular fat radiodensity and vascular calcification in midlife women: The SWAN cardiovascular fat ancillary study

“…15 Our EAT radiodensity exploratory findings where we found no association with CAC were consistent with Alvey et al and Lu et al 13, 35 In a study among men and women with confirmed or suspected coronary artery disease, Mahabadi et al found that EAT radiodensity was only mildly correlated with EAT volume and positively associated with type-I myocardial infarction. 36 In a study among primarily male patients suspected of CVD, Marwan et al found that pericoronary fat radiodensity was positively associated with coronary atherosclerotic plaque in unadjusted analyses. 37 …”

Perivascular adipose tissue and coronary atherosclerosis

“…Similarly, in 609 asymptomatic low-risk to intermediate-risk patients, Abazid et al 45 observed a negative correlation between EAT attenuation and coronary calcification independent of EAT volume. In contrast, in a cross-sectional analysis of patients with acute MI and stable CAD controls, Mahabadi et al 27 observed a positive association between EAT attenuation and type I acute MI, while Hell et al 35 did not report a link between EAT attenuation and myocardial ischaemia on SPECT. These contradicting results may be explained by a small sample size, the variable nature of the study population, as well as methodological limitations, such as selection bias, reverse causality and the presence of confounders that were not taken into account.…”

“…Indeed, EAT can be easily visualised by routine transthoracic echocardiography and its thickness in the anterior surface of the right ventricle can be measured in a safe and easy manner 26. However, the amount of EAT is more accurately and reproducibly quantified by cardiac CT or MRI 27. Most studies have relied on non-contrast CT scans for EAT segmentation; however, coronary CT angiography provides an optimal method of assessing not only the coronary anatomy, but also specific features of coronary PVAT.…”