Troponin T in the evaluation of prognosis in patients with unstable angina

441 Abstract: Cardiac troponin T (TnT) is a regulatory contractile protein not normally found in blood. Minor elevations of TnT in patients with unstable angina have been associated with an increased risk of subsequent death or Acute Myocardial Infarction (AMI). We used a neewly developed enzyme immunoassay for TnT to determine whether its presence in the serum of patients with unstable angina was a prognostic indicator. We screened 105 hatients with unstable angina (23 with accelerated or subacute angina and, 82 with acute angina at rest) for TnT every eight hours for two days after admission to the hospital. The outcomes of interest during the hospitalization were death and myocardial infarction. Troponin T was detected (range 0.20 to 3.64 μg per liter; mean 0.78; median, 0.50) in the serum of 32 of the 82 patients. (39 percent) with acute angina at rest. of the 33 patients who were positive for TnT, 10 (30 percent) had myocardial infarction (3 after coronary artery bypass surgery), and 5 of these died during hospitalization. In contrast only 1 of the 50 patients with angina at rest who were negative for troponin T had an acute myocardial infarction (p<0.001), and this patient died (p=0.03). Thus, 10 of the 11 patients with myocardial infarctions had detectable levels of TnT; troponin T was not detected in any of the 23 paitents with accelerated or subacute angina and none of these patients died. Conclusion: Cardiac troponin T is a cheap, simple and prognostically very useful indicator in patients with unstable angina.