THE PROGNOSTIC-SIGNIFICANCE OF TROPONIN-I AND TROPONIN-T

Objectives: To determine and compare the prognostic abilities of early , single-sample measurements of cardiac troponin I (cTn-I), cardiac tr oponin T (cTn-T), and creatine kinase-NIB (CK-MB) among ED patients wi th possible myocardial ischemia. Methods: Prospective collection of cl inical and serologic data using an identity-unlinked technique from pa tients with possible myocardial ischemia at 2 urban EDs. Outcome data concerning the occurrence of adverse events (AEs) during the 14 days a fter enrollment were used Do calculate and compare the relative risks (RRs) and predictive values (with 95% confidence intervals) of the 3 m arkers for predicting AEs. Results: Among the 401 study patients, 105 AEs occurred in 67 patients. cTn-I, cTn-T, and OK-ME were all signific antly predictive of AEs, with RRs of 3.87 (2.39, 6.26), 3.03 (1.92, 4. 79), and 6.45 (4.74, 8.77), respectively. For prediction of AEs, sensi tivity for each of the 3 markers was low (cTn-I = 15.38, cTn-T = 24.62 , OK-ME = 15.38), while specificity was high (cTn-I = 97.62, cTn-T = 9 3.15, CK-MB = 99.70). No significant difference in predictive ability was found between cTn-I and cTn-T. However, a positive CK-MB result wa s a stronger predictor of AEs than either cTn-I (p = 0.01) or cTn-T (p = 0.001). Conclusions: No significant difference in predictive abilit ies was found between cTn-I and cTn-T. However, routine testing for bo th CK-MB and either of the troponins may optimize early identification of high-risk patients so they may be targeted for a higher level of c are and consideration of more aggressive therapies.