Usefulness of High-Sensitivity Cardiac Troponin T for the Identification of Outlier Patients With Diffuse Coronary Atherosclerosis and Low-Risk Factors

Abstract

Novel high-sensitivity assay can detect very low levels of circulating cardiac troponin (hs-cTnT) in apparently healthy subjects. Within normal range, higher levels are associated with coronary artery disease (CAD) and cardiac abnormalities commonly associated to traditional risk factors (RFs) for CAD. Therefore, we investigated the relation between circulating hs-cTnT and CAD in patients with a spectrum of RF burden aiming to assess the added value of hs-cTnT to identify "outlier" patients with CAD despite a low RF burden. Hs-cTnT was measured in 525 stable patients without previous diagnosis of ischemic heart disease with 0 to 1 RF, excluded diabetes, (low-RF group, n= 263) or ≥2 RFs (multiple-RF group, n= 262) and without CAD (segment involvement score= 0) or diffuse CAD (segment involvement score >5) at coronary computed tomography angiography. Outlier patients with diffuse CAD despite low-RF burden had similar extent, severity, and plaque composition than patients with multiple RFs. Overall, hs-cTnT was measurable in 81% of patients with median value of 6.0ng/L. In both groups, hs-cTnT concentration was higher in patients with CAD than in patients with normal coronary arteries (p <0.0001). Hs-cTnT was more accurate to detect patients with CAD in the low-RF group than in the multiple-RF group (p= 0.04). In multivariate analysis, higher level of hs-cTnT (>6ng/L) was independently associated with CAD in low-RF group only. Despite very low circulating concentrations, hs-cTnT may identify with a good accuracy the outlier patients with diffuse CAD despite low-RF burden.