The Prognostic Significance of Troponin-T in Patients with Acute Myocardial Infarction: Can Late Peak Concentration of Troponin-T after Myocardial Infarction Predict Cardiovascular Events?

ABSTRACT

BACKGROUND AND OBJECTIVES: It has been demonstrated that the estimated infarct size is a prognostic variable which significantly influences the short-term and long-term prognosis after an acute myocardial infarction (AMI). Recently, the late peak level of troponin-T has been determined as a reliable and simple non-invasive method for estimation of infarct size. This study was performed to determine whether the late peak level of troponin-T can be used to predict cardiovascular events during in-hospital stay and out-patient follow-up in patients with AMI. MATERIALS AND METHOD: The study was comprised 100 patients (male 91, mean age 57+/-1 years) with AMI and thrombolysis which was initiated within 6 hours after the onset of symptoms. The late peak concentration of troponin-T was defined as a more larger level between 48 and 72 hours after thrombolysis. We investigated the factors influencing on the late peak level of troponin-T and assessed the relation of the late peak level and cardiovascular events. RESULTS: 1) The late peak level of troponin-T was significantly correlated with the peak creatine kinase (CK) level, (r=0.69, p=0.0001) but not ejection fraction of left ventricle (LVEF) at 7 days after AMI. The late peak level of troponin-T was significantly higher in patients with LVEF of <40% at 7 days after AMI (13.49+/-3.62 vs. 6.44+/-0.72, p=0.035) but not different by location of AMI and reperfusion status. 2) During clinical follow-up at a mean duration of 27 months, 1 cardiac death, 10 congestive heart failure, 8 recurrent infarction, and 20 post-myocardial infarction angina were occurred. 3) In patients who occurred cardiac events during in-hospital stay, the peak level of CK (4377+/-938 vs. 2661+/-234, p=0.001) and TIMI forward flow grade < 3 (5/13 vs. 6/55, p=0.022) were significantly higher, but the late peak level of troponin-T (8.69+/-1.22 vs. 6.91+/-0.79, p=0.021) and the peak level of troponin-T (21.09+/-2.29 vs. 13.28+/-1.37, p=0.021) were significantly higher in patients who occurred cardiac events during out-patient follow-up. On multi-variate analysis by logistic regression, the late peak level of troponin-T was predicted the cardiac events during clinical follow-up (CI 1.022-1.196, p=0.022). CONCLUSIONS: The late peak level of troponin-T is significantly correlated with peak CK level and higher in patients with LVEF of patients who occurred cardiac events during clinical follow-up. These results sugggest that the late peak level of troponin-T is a simple and useful non-invasive method to predict the cardiac events during clinical follow-up in patients with acute myocardial infarction.