Background. The prognosis of patients hospitalized with acute myocardial ischemia is quite variable. We examined the value of serum levels of cardiac troponin T, serum creatine kinase MB (CK-MB) levels, and electrocardiographic abnormalities for risk stratification in patients with acute myocardial ischemia. Methods. We studied 855 patients within 12 hours of the onset of symptoms. Cardiac troponin T levels, CK-MB levels, and electrocardiograms were analyzed in a blinded fashion at the core laboratory. We used logistic regression to assess the usefulness of baseline levels of cardiac troponin T and CK-MB and the electrocardiographic category assigned at admission-ST- segment elevation, ST-segment depression, T-wave inversion, or the presence of confounding factors that impair the detection of ischemia (bundle branch block and paced rhythms)-in predicting outcome. Results. On admission, 289 of 801 patients with base-line serum samples had elevated troponin T levels (>.0.1 ng per milliliter). Mortality within 30 days was significantly higher in these patients than in patients with lower levels of troponin T (11.8 percent vs. 3.9 percent, P<0.001). The troponin T level was the variable most strongly related to 30-day mortality (chi-square=21, P<0.001), followed by the electrocardiographic category (chi-square=14, P=0.003) and the CK-MB level (chi-square = 11, P = 0.004). Troponin T levels remained significantly predictive of 30-day mortality in a model that contained the electrocardiographic categories and CK-MB levels (chi-square=9.2, P=0.027). Conclusions. The cardiac troponin T level is a powerful, independent risk marker in patients who present with acute myocardial ischemia. It allows further stratification of risk when combined with standard measures such as electrocardiography and the CK-MB level.
ASJC Scopus subject areas