This study was designed to clarify the influence of pericoronary adipose tissue (PAT) on plaque vulnerability using coronary computed tomography angiography (CCTA). A total of 103 consecutive patients who underwent CCTA and subsequent percutaneous coronary intervention (PCI) using intravascular ultrasound (IVUS) for coronary artery disease were enrolled. The PAT ratio was calculated as the sum of the perpendicular thickness of the visceral layer between the coronary artery and the pericardium, or the coronary artery and the surface of the heart at the PCI site, divided by the PAT thickness without a plaque in the same vessel. PAT ratios were divided into low, mid and high tertile groups. Epicardial adipose tissue (EAT) thickness was measured at the eight points surrounding the heart. Multivariate logistic analysis was performed to determine whether the PAT ratio is predictive of vulnerable plaques (positive remodeling, low attenuation and/or spotty calcification) on CCTA or echo-attenuated plaque on IVUS. The Hounsfield unit of obstructive plaques >50% was lower in the high PAT group than in the mid and low PAT groups (47.5 ± 28.8 vs. 53.1 ± 29.7 vs. 64.7 ± 27.0, p = 0.04). In multivariate logistic analysis, a high PAT ratio was an independent, associated factor of vulnerable plaques on CCTA (OR: 3.55, 95% CI: 1.20-10.49), whereas mean EAT thickness was not (OR: 1.22, 95% CI: 0.82-1.83). We observed a similar result in predicting echo-attenuated plaque on IVUS. PAT ratio on CCTA was an associated factor of vulnerable plaques, while EAT was not. These results support the important concept of local effects of cardiac adipose tissue on plaque vulnerability.
Keywords: Coronary atherosclerosis; Coronary computed tomography angiography; Epicardial adipose tissue; Pericoronary adipose tissue; Vulnerable plaque.