Peri-Coronary Adipose Tissue Density Is Associated With 18F-Sodium Fluoride Coronary Uptake in Stable Patients With High-Risk Plaques

OBJECTIVES This study aimed to assess the association between increased lesion pen-coronary adipose tissue (PCAT) density and coronary F-18-sodium fluoride (F-18-NaF) uptake on positron emission tomography (PET) in stable patients with high-risk coronary plaques (HRPs) shown on coronary computed tomography angiography (CTA). BACKGROUND Coronary F-18-NaF uptake reflects the rate of calcification of coronary atherosclerotic plaque. Increased PCAT density is associated with vascular inflammation. Currently, the relationship between increased PCAT density and F-18-NaF uptake in stable patients with HRPs on coronary CTA has not been characterized. METHODS Patients who underwent coronary CTA were screened for HRP, which was defined by 3 concurrent plaque features: positive remodeling; low attenuation plaque (LAP) (<30 Hounsfield units [HU]) and spotty calcification; and obstructive coronary stenosis >= 50% (plaque volume >100 mm(3)). Patients with HRPs were recruited to undergo F-18-NaF PET/CT. In lesions with stenosis >= 25%, quantitative plaque analysis, mean PCAT density, maximal coronary motion-corrected F-18-NaF standard uptake values (SUVmax), and target-to-background ratios (TBR) were measured. RESULTS Forty-one patients (age 65 +/- 16 years; 68% men) were recruited. Fifty-one lesions in 23 patients (56%) showed increased coronary F-18-NaF activity. Lesions with F-18-NaF uptake had higher surrounding PCAT density than those without F-18-NaF uptake (-73 HU; interquartile range 79 to 68 HU vs. 86 HU; interquartile range 94 to 80 HU; p < 0.001). F-18-NaF TBR and SUVmax were correlated with PCAT density (r 0.63 and r 0.68, respectively; all p < 0.001). On adjusted multiple regression analysis, increased lesion PCAT density and LAP volume were associated with F-18-NaF TBR (beta = 0.25; 95% confidence interval: 0.17 to 0.34; p < 0.001 for PCAT, and (beta = 0.07; 95% confidence interval: 0.03 to 0.11; p = 0.002 for LAP). CONCLUSIONS In patients with HRP features on coronary CTA, increased density of PCAT was associated with focal F-18-NaF PET uptake. Simultaneous assessment of these imaging biomarkers by F-18-NaF PET and CTA might refine cardiovascular risk prediction in stable patients with HRP features. (C) 2019 by the American College of Cardiology Foundation.