Biomarkers for identification of high-risk coronary plaques in patients with suspected coronary artery disease

Abstract Background Patients with atherosclerotic plaques containing high-risk features have an increased likelihood of events and a worse prognosis. Whether elevated levels of biomarkers of ischemia e.g. TnI and inflammation e.g. high sensitive C-reactive protein (hsCRP) are associated with the presence of high-risk coronary atherosclerotic plaques (HRP) evaluated on coronary computed tomography angiography (CCTA) is not well described. Objectives To assess the association between 1) TnI and 2) hsCRP and quantified coronary plaque burden, luminal diameter stenosis and HRP in symptomatic patients with low/intermediate pre-test probability of obstructive coronary artery disease (CAD) referred to CCTA evaluation. Methods On enrolled patients (n=1,615), CCTA were analysed using a semiautomatic software for coronary artery plaque characterization. Patients with high (>6 ng/L) and low (<3 ng/L) TnI as well as high (>2 mg/L) and low (<1 mg/L) hsCRP were identified. Associations of high levels of TnI and hsCRP compared to low levels were investigated for the following: high plaque burden (defined as having total plaque volume above the 75th percentile on CCTA), presence of significant stenosis (defined as ≥50% luminal diameter stenosis on CCTA), and presence of HRP (defined as having a plaque with at least two risk features on CCTA). Results TnI and hsCRP were both positively correlated with total plaque burden (TnI rs=0.14, p<0.001; hsCRP rs=0.08, p<0.001). In multivariate logistic regression analyses, high TnI was when compared to low TnI associated with presence of stenosis (OR 1.43, 95% confidence interval (CI) 1.03-1.99, p=0.034), the presence of HRP (OR 1.79, 95% CI: 1.17– 2.74, p=0.008) and further the subtypes of HRP including low attenuation plaque (OR 1.93, 95% CI: 1.24–3.00, p=0.003) and positive remodelling (OR 1.51, 95% CI: 1.07–2.13, p=0.018). For high hsCRP levels, only the presence of stenosis and the HRP-subtype napkin ring sign correlated significantly. Conclusion In patients with suspected CAD TnI and hsCRP are associated with the presence of HRP features. These findings suggest that inflammatory and particularly ischemic biomarkers might improve early risk stratification and potentially also affect patient management.