06 Feb 18. Featured paper
18F–sodium fluoride uptake in abdominal aortic aneurysms: the SoFIA3 study
Rachael O. Forsythe MD, Marc R. Dweck MD, Olivia M.B. McBride MD, Alex T. Vesey MD, Scott I. Semple PhD, Anoop S.V. Shah MD, Philip D. Adamson MD, William A. Wallace MD, Jakub Kaczynski MD, Weiyang Ho MD, Edwin J.R. van Beek MD, Calum D. Gray PhD, Alison Fletcher PhD, Christophe Lucatelli PhD, Aleksander Marin MD, Paul Burns MD, Andrew Tambyraja MD, Roderick T.A. Chalmers MD, Graeme Weir MD, Neil Mitchard BS, Adriana Tavares PhD, Jennifer M.J. Robson MD, David E. Newby MD
Fluorine-18–sodium fluoride (18F-NaF) uptake is a marker of active vascular calcification associated with high-risk atherosclerotic plaque.
In prospective case-control (n = 20 per group) and longitudinal cohort (n = 72) studies, patients with AAA (aortic diameter >40 mm) and control subjects (aortic diameter <30 mm) underwent abdominal ultrasound, 18F-NaF PET-CT, CT angiography, and calcium scoring. Clinical endpoints were aneurysm expansion and the composite of AAA repair or rupture.
Fluorine-18-NaF uptake was increased in AAA compared with nonaneurysmal regions within the same aorta (p = 0.004) and aortas of control subjects (p = 0.023). Histology and micro-PET-CT demonstrated that 18F-NaF uptake localized to areas of aneurysm disease and active calcification. In 72 patients within the longitudinal cohort study (mean age 73 ± 7 years, 85% men, baseline aneurysm diameter 48.8 ± 7.7 mm), there were 19 aneurysm repairs (26.4%) and 3 ruptures (4.2%) after 510 ± 196 days. Aneurysms in the highest tertile of 18F-NaF uptake expanded 2.5× more rapidly than those in the lowest tertile (3.10 [interquartile range (IQR): 2.34 to 5.92 mm/year] vs. 1.24 [IQR: 0.52 to 2.92 mm/year]; p = 0.008) and were nearly 3× as likely to experience AAA repair or rupture (15.3% vs. 5.6%; log-rank p = 0.043).
Fluorine-18-NaF PET-CT is a novel and promising approach to the identification of disease activity in patients with AAA and is an additive predictor of aneurysm growth and future clinical events. (Sodium Fluoride Imaging of Abdominal Aortic Aneurysms [SoFIA3]; NCT02229006; Magnetic Resonance Imaging [MRI] for Abdominal Aortic Aneurysms to Predict Rupture or Surgery: The MA3RS Trial; ISRCTN76413758)