Cardiac troponin T predicts occult coronary artery stenosis in patients with chronic kidney disease at the start of renal replacement therapy

Abstract

The high prevalence of asymptomatic coronary artery stenosis (CAS) in chronic kidney disease (CKD) has emerged as an important predictor of outcome. However, diagnostic tools that can identify asymptomatic CAS have not yet been established. We investigated whether asymptomatic patients at the initiation of renal replacement therapy (RRT) could be screened using cardiac troponin T (cTnT) and atherosclerotic surrogate markers such as ankle-brachial blood pressure index (ABPI) and intima-media thickness (IMT). Among 142 patients who were about to start RRT, 60 who were asymptomatic underwent coronary evaluation by multi-slice computed tomography (MSCT) and/or coronary angiography (CAG). CAG diagnosed 35 patients (43.8%) as CAS positive and 27 of them had multi-vessel disease. Factors associated with CAS were smoking, elevated cTnT, low ABPI and high IMT. Moreover, the severity of CAS was associated with smoking, cTnT and ABPI. Stepwise logistic regression analyses revealed that cTnT was a powerful predictor of asymptomatic multi-vessel CAS. Receiver operating characteristic analysis documented the usefulness of cTnT as a screening tool with a cut-off point 0.05 ng/ml. The optimal screening tool for multi-vessel CAS was cTnT (sensitivity, 92.6%; 95% CI, 82.7-99.9; specificity, 63.6%; 95% CI, 47.2-80.0). We concluded that cTnT should be measured as part of a strategy for detecting asymptomatic CAS, especially multi-vessel disease in patients with CKD at the start of RRT.