Clinical Investigations Serum Troponin T in Acute Myocardial Infarction

Troponin T (Tn-T) is a cardiospecific antigen released from the damaged myocardium. The serum levels of Tn-T in healthy individuals are negligible. These properties suggested that Tn-T might be useful in the diagnosis of AMI. To evaluate the release profile of Tn-T and compare it with CK-MB levels, 15 patients who were hospitalized in the Coronary Care Unit of the Hacettepe University hospital with chest pain and typical ECG changes of AMI were studied (10 male, 5 female, age 35-68; mean age 54). Only patients who did not receive thrombolytic therapy were evaluated to study the natural release curve of Tn-T. Serum levels of Tn-T and CK-MB Tn-T and CK-MB levels increased within a few hours. Tn-T levels peaked at 24 hours, followed by a plateau and started to decrease on the 4th day. CK-MB levels peaked at 12 hours. The sensitivity of Tn-T at 6, 12, 48, hours and 7 days was 54, 73, 100, 86 %, respectively. The sensitivity of CK-MB at the same time intervals was 54, 86, 100, 60, 0 % respectively. Both medhods were useful for the early diagnosis of acute myocardial infarction (p>0.05). However, Tn-T was more sensitive after 36 hours (p<0.05). We concluded that Tn-T levels start to increase within a few hours similar to CK-MB but stay elevated for a longer period of time permitting a longer diagnostic window. Although Tn-T cannot replace CK-MB in the early diagnosis of AMI, it will be a helpful alternative in patients with borderline CK-MB levels or those who are first seen later in the course of myocardial infarction.