The Diagnostic Value of Cardiac Troponin T in the Detection of Acute Myocardial Infarction in Hospital USM Patients

Acute myocardial infarction (AMI) was defined based on clinical findings, ECG abnormalities and cardiac enzymes. However with sensitive marker such as troponin the definition has been refined. In this study two cut-off values of troponin T (0.03ng/mL and 0.1ng/mL) were compared with the final diagnosis of AMI made by the physician. This was a retrospective study to determine the efficiency of cardiac troponin T in the diagnosis of AMI. Receiver operating curve (ROC) was obtained and calculated to determine the best cut-off point for troponin T. A total of 246 patients with acute coronary syndrome were recruited. Out of these, 48.8% of patients had AMI with 36.2% of them diagnosed as non-ST elevation MI and 12.6% as ST-elevation MI. The remaining 51.2% were diagnosed as unstable angina. Troponin T at the cut-off value of 0.03ng/mL had high sensitivity with low specificity (94.2% and 87.3%, respectively) whereas cut-off value of 0.1ng/mL had low sensitivity with high specificity (76.7% and 96.8%, respectively). The optimal cut-off value of troponin T in our patients was 0.037ng/mL with sensitivity and specificity of 90.0% and 90.5 %. Therefore, the best cut-off value of troponin T for the diagnosis of AMI was 0.037ng/mL with area under curve of 0.9652. However for the diagnosis, it should be matched with clinical findings.