Association of inflammation of the left anterior descending coronary artery with cardiovascular risk factors, plaque burden and pericardial fat volume: a PET/CT study

Measurements of [F-18]fluorodeoxyglucose (FDG) uptake as a potential marker of the inflammatory activity of the vessel wall could be useful to identify vulnerable atherosclerotic plaques. The purpose of this study was to correlate the FDG uptake in the left anterior descending coronary artery (LAD) with cardiovascular risk factors, pericardial fat volume (PFV) and calcified plaque burden (CPB). A total of 292 consecutive tumour patients were examined by whole-body FDG PET and contrast-enhanced CT. The blood pool-corrected standardized uptake value (target to background ratio, TBR) was measured in the LAD, and the contrast-enhanced CT images were used to measure the PFV and the CPB. The Spearman correlation coefficient and the unpaired t test were used for statistical comparison between image-based results and cardiovascular risk factors. Vascular FDG uptake could be measured for 161 of 292 (55%) patients without myocardial uptake, but the vessel uptake could not be distinguished in the other patients, due to pervasive myocardial uptake. The TBR of the LAD showed significant correlations with hypertension (R = 0.18; p < 0.05), coronary heart disease (R = 0.19; p < 0.05), body mass index (BMI) (R = 0.19; p < 0.05), CPB (R = 0.36; p < 0.001) and PFV (R = 0.20; p < 0.05), but not with other risk factors. Patients with a TBR in the upper tertile had a larger CPB and a higher PFV than patients with a TBR in the lower tertile (9.1 vs 3.5; p < 0.001 for CPB and 92.2 vs 71.5 mm(3); p < 0.05 for PVF). FDG uptake measurement in the LAD correlates with hypertension, coronary heart disease, BMI, PFV and CPB. However, due to myocardial FDG uptake these measurements are only feasible in one half of the patients.