Diagnosis of AMI in the patients presenting with chest pain of an atypical nature or with a nondiagnostic ECG requires the evaluation of certain biochemical markers. Biochemical markers most often used for the early detection of myocardial damage are CK-MBact, troponin, and myoglobin. The clinical value of measuring serum myoglobin was compared to that of troponin and CK-MBact in the patient with acute chest pain syndrome.

We studied timed, sequential measurements of serum myoglobin, CK-MBact and troponin-T obtained from 72 patients who were admitted for the evaluation of suspected AMI within 12 hours after the chest pain onset. Patients with a history of recent trauma, cardiogenic shock, renal failure, or who had received recent cardiopulmonary resuscitation were excluded. We calculated the sensitivity, specificity, negative predictive value, and positive predictive value. Data were analyzed with the Chi-square test for differences in proportion. A value of p<0.05 was considered statistically significant.

1) The mean time from symptom onset to arrival at the emergency department was 3.5±0.6 hours. 2) There were no statistical differences in age, sex and risk factors between AMI, angina pectoris and atypical chest pain group. 3) The negative predictive value of myoglobin was significantly higher than those of CK-MBact and troponin-T from 3 to 6 hours after the onset of chest pain. 4) The time to peak of myoglobin level was shorter than those of CK-MBact and troponin-T in AMI patients.

Within 3 to 6 hours after the onset of symptoms, myoglobin is a better marker than CK-MBact or troponin-T in ruling out AMI for the patient with acute chest pain syndrome.