Background: New cardiac markers that may be analysed around the clock in emergency can now be performed in our hospitals with commercially available reagents and equipment. Upon the introduction of a new clinical biochemical regime based on these new markers for the diagnosis of acute coronary syndromes, we evaluated the clinical benefit achieved by the new set-up, especially with respect to early diagnosis.
Material and methods: cTroponinT, CK-MBmass, myoglobin and total-CKactivity were analysed in blood sample taken on admission, after 2-3 hours, and further once or twice over the next 24 hours in 300 patients admitted on suspicion of acute coronary syndromes (ACS). The study was based on results of the cardiac markers and information given on questionnaires by the physicians in charge.
Results: With the decision limits applied, CK-MB and myoglobin showed slightly higher sensitivity than cTroponinT for detecting acute myocardial infarction within the first 2-3 hours. cTroponinT showed the highest sensitivity for detecting heart muscle damage in patients with unstable angina. cTroponinT was the most cardiospecific marker. If the patient was considered not having ACS after the first few hours, only 3% ended with a diagnose of unstable angina and none with acute myocardial infarction. Of those considered certain ACS cases after the first few hours, 92% ended up with the diagnosis acute myocardial infarction or unstable angina. Treatment and/or supervision were changed in 68 of 220 patients based on the results of the two first blood samples, 85% of them to a lower level of supervision.
Interpretation: cTroponinT and CK-MB are useful markers for early detection of acute myocardial injuries. A prerequisite is that they are determined in two samples with an interval of at least two hours. In this case, myoglobin did not give additional information. Based on the results from two early blood samples, about one quarter of the patients could immediately be transferred to a less expensive level of care.