LAUSR

BACKGROUND AND AIMS Atherosclerotic plaque molecular imaging with 18F-sodium fluoride (NaF) in positron emission tomography with computed tomography (PET-CT) provides potential discrimination between active unstable microcalcification and established dormant calcification. We aimed to study 18F-NaF atherosclerotic plaque uptake in high cardiovascular (CV) risk participants and its associations with CV risk factors, coronary calcium score and thoracic fat volume. METHODS High CV risk hypertensive individuals from a single centre were prospectively scanned with 18F-NaF-PET-CT in the coronary, aortic and carotideal arteries. Atherosclerotic plaque 18F-NaF uptake was expressed as Corrected Uptake per Lesion (CUL): maximum standard uptake value in each vascular territory subtracted by mean blood pool activity. RESULTS Mean age was 64 years, 56% male and 96% Caucasian (n = 25). Ninety six per cent of the subjects showed 18F-NaF uptake in the aorta (CUL 0.9 ± 0.3), 40% in the carotid arteries (median CUL 0.0, IQR 0.0-0.7) and 64% in the coronary arteries (0.4, IQR 0.0-0.6). Individuals with ≥ five risk factors (60%) had increased overall 18F-NaF uptake (1.1 ± 0.3 vs. 0.7 ± 0.3, p < 0.01), which was positively correlated with predicted fatal CV risk - SCORE (r = 0.49, p = 0.01). There was no correlation between 18F-NaF uptake in the coronary arteries and calcium score (p = 0.87). Thoracic fat was moderately correlated with overall CUL (r = 0.41, p = 0.04). CONCLUSIONS In a high CV risk group, 18F-NaF atherosclerotic plaque uptake was related to the burden of CV risk factors and thoracic fat volume, but there was no association between coronary uptake and calcium score.