THE PROGNOSTIC VALUE OF SERUM TROPONIN-T IN UNSTABLE ANGINA

Background: Cardiac troponin T is a regulatory contractile protein not normally found in blood. Its detection in the circulation has been sh own to be a sensitive and specific marker for; myocardial cell damage. We used a newly developed enzyme immunoassay fbr troponin T to determ ine whether its presence in the serum of patients with unstable angina was a prognostic indicator. Methods: We screened 72 patients with uns table angina (Class III, acute unstable angina) for serum creatine kin ase activity, creatine kinase myocardial band (isoenzyme M) activity, and troponin T, every 8 h for 2 days after admission to the hospital. The outcomes of interest during the hospitalization were death and myo cardial infarction. Results: Troponin T was detected in the serum of 2 4 of the 72 patients (34%) with acute angina at rest. Only four of the se patients had elevated creatine kinase M activity. Of the 24 patient s who were positive for troponin T, 12 had myocardial infarction, and 6 of these died during hospitalization. In contrast, only 2 of the 48 patients with angina at rest who were negative for troponin T had an a cute myocardial infarction, and these patients died. Thus, 12 of the 1 4 patients with myocardial infarctions had detectable levels of tropon in T; only 2 had elevated creatine kinase M activity. Conclusions: Car diac troponin T in serum appears to be a more sensitive indicator of m yocardial-cell injury than serum creatine kinase MB activity, and its detection in the circulation may be a useful prognostic indicator in p atients with unstable angina.