EARLY DIAGNOSIS AND EXCLUSION OF ACUTE MYOCARDIAL-INFARCTION USING BIOCHEMICAL MONITORING

Background: The aim was to evaluate whether frequent analysis of creat ine kinase MB (CK-MB), myoglobin and troponin T alone or in combinatio n could either confirm or exclude acute myocardial infraction (AMI) wi thin the first few hours after patients were admitted to hospital with chest pain and a non-diagnostic EGG. Methods: One hundred and forty-t wo patients with chest pain (less than or equal to 12h) and a non-diag nostic ECG were included in the study. Blood samples were obtained eve ry 30 min during the first 3 h and thereafter at longer intervals. Dif ferent discriminatory levels and combinations of markers were tested f or their ability to detect (n = 59) or exclude (n = 83) AMI during the first 6 h after admission. Results: No single marker adequately combi ned high early sensitivity and specificity. However, a combination of myoglobin and CK-MB analyses had a sensitivity at entry of 59%, which increased by 5-10% every 30 min and reached 92% after 2 h and 98% afte r 6 h with a specificity of 93%. A combination of myoglobin and tropon in T analyses showed identical sensitivity but a slightly inferior spe cificity. In the patients with no AMI it was possible to exclude AMI i n 64% within 3h by using myoglobin and within 6h in approximately 70% by using CK-MB or troponin T. Conclusions: Monitoring of a combination of myoglobin and CK-MB or troponin T will allow confirmation or exclu sion of AMI within 3-6 h in almost all patients. This method will have a large impact on the handling of patients with suspected AMI without a diagnostic EGG.