Possible reasons for the prognostic value of troponin-T on admission in patients with ST-elevation myocardial infarction

BACKGROUND: In patients with acute myocardial infarction and ST-segment elevation, increased troponin-T (TnT) on admission implies an increased mortality. OBJECTIVE: To elucidate the underlying mechanisms of the prognostic value of TnT. METHODS AND RESULTS: One hundred and one patients were included and all received thrombolytic treatment. The patients were compared according to TnT level on admission (cut-off 0.1 microg/l). Elevation of TnT was associated with long-term mortality and also with longer delay, more episodes of chest pain during the last 24 h and fewer noninvasive signs of reperfusion at 90 min. In the group with elevated TnT, the coronary angiography at 24 h showed a strong trend towards lower patency in the infarct-related artery. TnT was also associated with increased infarct size if a higher cut-off level (0.43 microg/l) was used. In univariate analysis, elevated TnT, longer delay, repeated chest pain, Q-waves on admission and reduced left ventricular (LV) function were significantly associated with long-term mortality. In multivariate models, only reduced LV function and less than TIMI (thrombolysis in myocardial infarction) grade 3 flow turned out to be significant independent risk factors. CONCLUSIONS: The prognostic value of TnT level on admission regarding long-term mortality was confirmed and seems mainly to be explained by its association with longer delay and recent myocardial damage, but its association with reduced effect of thrombolytic treatment, larger infarct size and impaired LV function might also be of importance.