Diagnostic Value of Cardiac Creatin Kinase and Cardiac Troponin I Measurement in Suspected Myocardial Infarction Patients

Based on previous studies, the clinical sensitivity of cardiac troponin I (cTnI) is higher than creatine kinase MB (CK-MB) in diagnosing acute coronary syndromes. The present study aimed to assess the diagnostic accuracy of cTnI and CK-MB biomarkers in diagnosing suspected myocardial infarction (MI).

In this descriptive study, 453 patients suspected of acute coronary syndrome who visited the emergency department of Farshchian Hospital in Hamadan in 2017 with chest pain were included. Of these, 360 patients had MI, and 93 patients did not have MI. In order to measure serum levels of CK-MB and cTnI, blood samples were taken from patients at the beginning and one and six hours later. The sensitivity and specificity of CK-MB and cTnI enzymes in MI were compared.

The sample size of this research was 453 cases, of which 66.45% were male and 33.55% were female. The mean age of subjects was 65.28±14.38 years. The sensitivity and specificity of cTnI in the diagnosis of MI were 96.67% and 100%, respectively. The sensitivity and specificity of CK-MB in diagnosing MI were 81.11% and 12.90%, respectively. The positive and negative predictive values of cTnI were 88.57 and 100, respectively, while the positive and negative predictive values of CK-MB were 78.28 and 15%, respectively. The accuracy of cTnI in differentiating cases of MI from non-MI (97.35%) was higher than that of CKMB (67.08%).

As evidenced by the obtained results, the sensitivity, specificity, and accuracy of cTnI detection in MI cases were higher than CK-MB. Therefore, troponin is a better marker than creatine kinase to identify patients with myocardial infarction.