PET imaging of vulnerable coronary artery plaques

Purpose In the last years, the identification of vulnerable atherosclerotic plaques to prevent acute coronary events has been one of the main objectives of the cardiovascular science community. In this review, we provide an overview of vulnerable coronary artery plaque imaging by positron emission tomography (PET). Methods and results Relevant methodological and technical aspects of PET on coronary artery plaque imaging are first analysed. Second, the main radiotracers used in this area as well as the main results of the clinical studies published so far are described. From published data, specialized approaches are recommended for imaging protocol and quantitative analysis of plaque activity. F-18-fluorodeoxyglucose (F-18-FDG), the first radiotracer used for its wide availability, has several limitations for the detection and quantification of coronary artery plaque inflammation. F-18-sodium fluoride (F-18-NaF), a marker of vascular microcalcification, seems to be the most promising radiotracer for vulnerable coronary artery plaque imaging. Ga-68-DOTATATE and Ga-68-pentixafor have also shown interesting results on coronary plaque inflammation in humans. Data on coronary imaging in humans are lacking for other radiotracers that target inflammation, hypoxia and neoangiogenesis. Conclusions Molecular imaging by PET is a powerful tool for imaging different components of vulnerable coronary artery plaques and, potentially, for selecting patients at high-risk of myocardial infarction for personalized treatments. However, the results of large clinical trials on asymptomatic patients to link coronary plaque activity to patient outcome are strongly required.