Serum and plasma as alternative sample types in analysis of cardiac markers in the clinical routine

There is an increasing demand for the results of cardiac markers (troponin I or T, creatine kinase MB mass and myoglobin) to be made available promptly after sample-taking. In order to shorten the turnaround time, the possibility of using EDTA- or heparin-plasma instead of serum was investigated. The study population comprised 391 patients with acute chest pain. Four different instruments and systems routinely used in Finland giving quantitative results were studied for the assays of creatine kinase isoenzyme MB mass, myoglobin, and troponin I or troponin T. In addition to serum samples, heparin-plasma seems to be useful for all three assays using the Access and Immulite systems, while EDTA-plasma seems to be useful for all three assays with the Access and Elecsys systems. For the AxSYM assays, serum samples seem to be the best alternative. In conclusion, it is possible to use a single EDTA- or heparin-plasma sample for Access, Elecsys and Immulite analysers, and thereby to shorten the turnaround time. In this way the quantitative analyses from plasma can be performed 30 min after taking the sample.