Arterial involvement has been implicated in the coronavirus disease of 2019 (COVID-19). 18F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging is a valuable tool for the assessment of disease severity in different types of vasculitis and is a predictor of outcome. We sought to prospectively assess the presence of aortic inflammation and its time-dependent trend by measuring the 18-FDG uptake in PET/CT in patients with severe or critical COVID-19.
In this pilot case control study, we recruited 20 patients, who were admitted with severe or critical COVID-19 illness. Patients underwent imaging between 20 to 120 days after hospital admission. Ten age- and sex-matched individuals with prior history of malignancy but free of active disease served as the control group. Arterial inflammation was assessed by measuring 18-FDG uptake in PET/CT and calculating aortic target to blood ratio (TBR).
There was a significant correlation between aortic TBR values and time distance from diagnosis to 18F-FDG PET/CT scan (-rho- =0.547, p=0.015) even after adjustment for confounders (p=0.002). Patients who were scanned less than 60 days (median) from diagnosis had significantly higher TBR values compared to patients examined more than 60 days post-diagnosis (1.55 [1.47-1.61] vs 1.40 [1.33-1.45], respectively, p=0.013).
This is the first study suggesting that 18 FDG PET/CT imaging could be used for assessment of arterial inflammation in patients with severe/critical COVID-19. These findings may have important implications for the understanding of the pathophysiology and the course of the disease and for improving our preventive and therapeutic strategies.