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 : www.umin.ac.jp . Unique identifier: UMIN 000013735.