Determinants of High-Sensitivity Troponin T Among Patients with a Noncardiac Cause of Chest Pain

BACKGROUND: It is unknown to what extent noncardiac causes, including renal dysfunction, may contribute to high-sensitivity cardiac troponin T levels. METHODS: In an observational international multicenter study, we enrolled consecutive patients presenting with acute chest pain to the emergency department. Of 1181 patients enrolled, 572 were adjudicated by 2 independent cardiologists to have a noncardiac cause of chest pain. Multiple linear regression analyses were used to determine the important predictors of log-transformed high-sensitivity cardiac troponin T. Kaplan-Meier curve was used to assess the prognostic significance of high-sensitivity cardiac troponin T > 0.014 mu g/L (99th percentile). RESULTS: A total of 88 patients (15%) had high-sensitivity cardiac troponin T > 0.014 mu g/L. Less than 50% of cardiac troponins could be explained by known cardiac or noncardiac diseases. In decreasing order of importance, age, estimated glomerular filtration rate, hypertension, previous myocardial infarction, and chronic kidney disease (adjusted r(2) 0.44) emerged as significant factors in linear regression analysis to predict high-sensitivity cardiac troponin T. High-sensitivity cardiac troponin T was best explained by a linear curve with age as <= 0.014 mu g/L. Patients with high-sensitivity cardiac troponin T levels > 0.014 mu g/L were at increased risk for all-cause mortality (hazard ratio 3.0; 95% confidence interval, 0.8-10.6; P = .02) during follow-up. CONCLUSION: Among the known covariates, age and not renal dysfunction is the most important determinant of high-sensitivity cardiac troponin T. Because known cardiac and noncardiac factors, including renal dysfunction, explain less than 50% of high-sensitivity cardiac troponin T levels among patients with a noncardiac cause of chest pain, unknown or underestimated cardiac involvement during the acute presenting condition seems to be the major cause of elevated high-sensitivity cardiac troponin T. (C) 2012 Elsevier Inc. All rights reserved. The American Journal of Medicine (2012) 125, 491-498