18F-FDG uptake and calcifications on positron emission tomography/computed tomography in octogenarians with severe...

The degree of inflammation within the atherosclerotic plaque can be detected non-invasively by positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG). The incidence of aortic plaques with 18F-FDG increased uptake in octogenarians with aortic stenosis is unknown. Aim of this study was to evaluate the frequency of inflamed aortic atherosclerotic plaques in octogenarians with or without severe aortic stenosis and their correlations with calcifications.

The study group comprised 27 patients older than 80 years who underwent a 18FDG PET/CT. Nine patients with severe symptomatic aortic stenosis, eligible to TAVI procedure (TAVI Group), and 18 patients age and sex matched, without clinical evidence of aortic stenosis (No TAVI Group), were selected and analysed.

In the whole population 4/27 patients (9.3%) had a significant focal aortic vessel wall 18F-FDG increased uptake: 1 patient (11.1%) in TAVI group and 3 in non-TAVI Group (16.7%). Overall 81 aortic segments were analysed. 18F-FDG uptake rates were similar in the two groups (1/27, 3.7% in TAVI Group and 3/54, 5.5% in No TAVI Group, P=0.7). At CT scan calcifications were significantly more frequent in the TAVI Group compared to non-TAVI Group (23/27, 85.2% and 28/54, 51.8% P=0.005). None of the sites of arterial calcification had an increased focal 18F-FDG uptake.

Irrespectively to the presence of aortic stenosis, a significant FDG plaque uptake in octogenarians is rare while calcifications are extremely frequent.