Prognosis of non-obstructive coronary plaques with high-risk CT morphology

Abstract

Coronary computed tomography angiography (CTA) is an accurate non-invasive method for the detection of and especially ruling out obstructive coronary artery disease (CAD) in appropriately selected patients. After its arrival, it has become possible to evaluate both coronary anatomy and functional significance of stenosis non-invasively by combined or hybrid coronary CTA and myocardial perfusion imaging (MPI).1 Functionally significant CAD is currently the cornerstone for selection of further medical and invasive therapy,1 but the non-obstructive plaques are also common in patients referred for coronary CTA and might have significant implications for patients' prognosis.2 The majority of coronary thrombi and subsequent acute coronary syndromes (ACS) are caused by plaque rupture. Prototype of the rupture-prone plaque contains a large, lipid-rich necrotic core that is covered by a thin and inflamed fibrous cap, so-called thin-cap fibroatheroma (TCFA).3 The TCFA phenotype on radiofrequency intravascular ultrasound (IVUS virtual histology) imaging was associated with an increased risk of recurrent coronary events after an ACS in a prospective follow-up study.4 Of the events not related to the previous culprit lesion, most occurred at sites with TCFA, whereas the degree of stenosis was a poor predictor of plaque rupture as the average stenosis of culprit lesions at baseline was only 30%.4 The extent and composition of non-obstructive atherosclerotic plaque …