Objective: Troponin I is a reliable and sensitive marker which is used to evaluate the myocardial injury. However there are different cut-off values for Troponin I due to different measurement technics. Therefore it is recommended that laboratories must define their own cut-off values. The purpose of this study is to determine the most appropriate cut-off value for serum Troponin I to evaluate acute myocardial infarction.

Materials and Methods: In this study, 114 patients (mean of age 55 ± 16) who applied to the Emergency Department with chest pain were included. Troponin I levels were measured within 6 hours from the onset of clinical symptoms of the patients. The six of 114 patients were diagnosed as acute myocardial infarction according to the clinical features, ECG findings and cardiac enzymes. The cut-off values that show the optimum sensitivity and specificity were determined by Receiver Operator Characteristic analysis.

Results: According to the Receiver Operator Characteristic analysis, %80 sensitivity and %99 specificity were found when we used 0.17 ng/mL as the cut-off value.

Conclusion: Troponin I cut-off value for acute myocardial infarction diagnosis was determined as 0.17 ng/mL in our laboratory. However, each laboratory needs to determine most available cut-off value for their patient population.