Natural history of atherosclerotic disease progression as assessed by (18)F-FDG PET/CT.

The aim of this study was to assess the impact of cardiovascular risk factors and plaque inflammation on the progression of atherosclerosis as assessed by positron emission tomography/computed tomography (PET/CT) imaging with (18)F-radiolabled fluorodeoxyglucose ((18)F-FDG). This study was designed as a retrospective cohort study. Patients who received a (18)F-FDG PET/CT scan and follow-up scan 9-24 months later without systemic inflammation or steroid medication were eligible for the study. (18)F-FDG PET/CT included a full diagnostic contrast enhanced CT scan. Cardiovascular risk factors and medication were documented. Calcified plaque volume, lumen area and (18)F-FDG uptake, quantified by the target-to-background ratio (TBR), were measured in the carotid arteries, aorta and iliac arteries. Influence of cardiovascular risk factors and vessel wall inflammation on atherosclerotic disease progression was analyzed. Ninety-four patients underwent baseline and follow-up whole body (18)F-FDG PET/CT (mean follow-up time 14.5 ± 3.5 months). Annualized calcified plaque volume increased by 15.4 % (p < 0.0001), carotid and aortic lumen area decreased by 10.5 % (p < 0.0001) and 1.7 % (p = 0.045). There was no significant difference in (18)F-FDG uptake at baseline and follow-up (mean TBR 1.44 ± 0.18 vs. 1.42 ± 0.19, p = 0.18). Multiple linear regression analysis identified hypertension as an independent predictor for total, aortic and iliac calcified plaque volume progression (all p < 0.04). Carotid lumen reduction was predicted by hypercholesterolemia (p = 0.008) while aortic lumen reduction was associated with BMI and mean (18)F-FDG uptake (p ≤ 0.005). Furthermore we observed a dose response relationship between the number of cardiovascular risk factors and calcified plaque volume progression in the aorta (p = 0.03). Findings from this study provide data on the natural history of atherosclerotic disease burden in multiple vascular beds and emphasize the value of morphological and physiologic information provided by (18)F-FDG PET/CT imaging.