Determinants of Pericoronary Adipose Tissue Attenuation on Computed Tomography Angiography in Coronary Artery Disease

Abstract

Background Recent studies have reported the association between pericoronary inflammation assessed by pericoronary adipose tissue attenuation (PCATA) on computed tomography angiography and worse outcomes in patients with coronary artery disease. We investigated the determinants predicting increased PCATA in patients with known or suspected coronary artery disease. Methods and Results A total of 540 patients who underwent computed tomography angiography and invasive coronary angiography were studied. Mean computed tomography attenuation values of PCAT (-190 to -30 Hounsfield units) (PCATA) were assessed at the proximal 40-mm segments of all 3 major coronary arteries by crude analysis. Univariable and multivariable analyses were performed to determine the predictors of increased PCATA surrounding the proximal right coronary artery. Mean right coronary artery-PCATA was -72.22±8.47 Hounsfield units and the average of 3-vessel PCATA was -70.24±6.60 Hounsfield units. Multivariable linear regression analysis revealed that the independent determinants of right coronary artery-PCATA were male (β coefficient=4.965, P<0.001), left ventricular mass index (β coefficient=0.040, P=0.025), and angiographically significant stenosis (diameter stenosis >50%) (β coefficient=2.418, P=0.008). Sex-related determinants were NT-proBNP level (N-terminal pro-B-type natriuretic peptide; β coefficient <0.001, P=0.026), Agatston score (β coefficient=-0.002, P=0.010), left ventricular mass index (β coefficient=0.041, P=0.028), and significant stenosis (β coefficient=4.006, P<0.001) in male patients and left ventricular ejection fraction (β coefficient=-0.217, P=0.010) and significant stenosis (β coefficient=3.835, P=0.023) in female patients. Conclusions Right coronary artery-PCATA was associated with multiple clinical characteristics, established risk factors, and the presence of significant stenosis. Our results suggest that clinically significant factors such as sex, left ventricular hypertrophy, ejection fraction, calcification, and epicardial stenosis should be taken into account in the assessment of pericoronary inflammation using computed tomography angiography.

Keywords: adipose tissue; computed tomography angiography; coronary artery disease; inflammation.

Figure 1. Representative computed tomography (CT) images of a patient with stable coronary artery disease.

A, Three‐dimensional reconstruction of the heart. B, Curved planar reformation view shows an intermediate stenosis (dotted line) in the mid right coronary artery (RCA). C, Pericoronary adipose tissue (defined as the adipose tissue located within a radial distance from the outer wall equal to the diameter of the coronary vessel) at the proximal 40‐mm segment was traced. D, Cross‐sectional view shows an atherosclerotic plaque at the stenotic site. E, Histogram of CT attenuation within the traced proximal 10 to 50 mm segment revealed that the pericoronary adipose tissue attenuation (PCATA) in the RCA was −60.81 Hounsfield units (HU).

Figure 2. The comparisons (A) and the correlations (B) of pericoronary adipose tissue attenuation (PCATA) among the 3 epicardial coronary arteries, and the distribution of PCATA surrounding the right coronary artery (RCA) (C).

LAD indicates left anterior descending coronary artery; and LCx, left circumflex coronary artery.

Figure 3. Comparisons of pericoronary adipose tissue attenuation (PCATA) surrounding the right coronary artery (RCA) (A) and left anterior descending coronary artery (LAD) (B) according to the localization and the clinical presentation.

ACS indicates acute coronary syndrome; CAD, coronary artery disease; and HU, Hounsfield units.