Renal artery wall 18F-NaF activity and glomerular filtration rate

OBJECTIVES Atherosclerotic plaque molecular imaging with F-sodium fluoride (NaF) PET with computed tomography (PET-CT) may identify active unstable microcalcification. We sought to explore renal arteries calcification activity in a group of high cardiovascular (CV) risk subjects without manifest CV disease. METHODS High CV risk hypertensive individuals from a single centre were prospectively scanned with F-NaF-PET-CT in major vascular territories. Renal arterial wall activity was retrospectively analysed and expressed as the ratio between maximum standard uptake value in the lesion and mean blood pool activity in the superior vena cava [tissue-to-background ratio (TBR)]. We explored renal artery wall F-NaF activity's association to CV risk factors and renal function. RESULTS Mean age was 64 ± 8.6 years, 56% male, 96% Caucasian and 24% had chronic kidney disease (CKD) (n = 25). Six individuals (24%) showed renal artery wall radiotracer uptake (TBR 1.4 ± 0.4); these subjects were heavier, had higher triglycerides, high-sensitivity C-reactive protein and predicted CV risk (SCORE) compared to the remaining cohort (P < 0.05 for all comparisons). There was a trend toward higher F-NaF uptake in other major vessels and increased thoracic fat volume in subjects with renal artery wall uptake. Glomerular filtration rate (GFR) was lower in subjects with positive renal plaques (93.0 ± 29.7 vs. 65.0 ± 19.7 ml/min, P = 0.04). Renal artery radiotracer uptake and eGFR were inversely correlated (r = -0.42, P = 0.04). CONCLUSION In a high CV risk group without manifest CV disease, higher renal artery wall F-NaF activity is associated with superior predicted CV risk and lower GFR.