Predictive Value of (18)F‐Sodium Fluoride Positron Emission Tomography in Detecting High‐Risk Coronary Artery Disease in Combination With Computed Tomography

BACKGROUND: Application of (18)F‐sodium fluoride ((18)F‐NaF) positron emission tomography (PET) to coronary artery disease has attracted interest. We investigated the utility of (18)F‐NaF uptake for predicting coronary events and evaluated the combined use of coronary computed tomography (CT) angiography (CCTA) and (18)F‐NaF PET/CT in coronary artery disease risk assessment. METHODS AND RESULTS: This study included patients with ≥1 coronary atherosclerotic lesion detected on CCTA who underwent (18)F‐NaF PET/CT. High‐risk plaque on CCTA was defined as plaque with low density (<30 Hounsfield units) and high remodeling index (>1.1). Focal (18)F‐NaF uptake in each lesion was quantified using the maximum tissue:background ratio (TBR (max)), and maximum TBR (max) per patient (M‐TBR (max)) was determined. Thirty‐two patients having a total of 112 analyzed lesions were followed for 2 years after (18)F‐NaF PET/CT scan, and 11 experienced coronary events (acute coronary syndrome and/or late coronary revascularization [after 3 months]). Patients with coronary events had higher M‐TBR (max) than those without (1.39±0.18 versus 1.19±0.17, respectively; P=0.0034). The optimal M‐TBR (max) cutoff to predict coronary events was 1.28 (area under curve: 0.79). Patients with M‐TBR (max) ≥1.28 had a higher risk of earlier coronary events than those with lower M‐TBR (max) (P=0.0062 by log‐rank test). In patient‐based (n=41) and lesion‐based (n=143) analyses of CCTA findings that predicted higher coronary (18)F‐NaF uptake, the presence of high‐risk plaque was a significant predictor of both M‐TBR (max) ≥1.28 and TBR (max) ≥1.28. CONCLUSIONS: (18)F‐NaF PET/CT has the potential to detect high‐risk coronary artery disease and individual coronary lesions and to predict future coronary events when combined with CCTA. CLINICAL TRIAL REGISTRATION: URL: http://www.umin.ac.jp. Unique identifier: UMIN000013735.