Recent approaches to the standardization of cardiac markers.

The development of commercial assays for the determination of cardiac proteins has been one of the most important innovations in the field of cardiovascular diagnostics in the last decade. Some assays are, however, inadequately appraised prior to their introduction to clinical use. This paper focuses on some important preanalytical, analytical and interpretative problems, and summarizes the status of the ongoing local and international standardization efforts. The most urgent issue at the moment is the development of international reference materials, which can be used for the calibration of different assays, thus decreasing between-assay biases. In order to achieve comparability of test results, another important item is the standardization of the epitopes of the antibodies used for the assay development. Efforts to improve the precision of cardiac marker assays are also warranted. Finally, the effect of storage time and temperature on apparent marker concentration and the possible influence of different anticoagulants on measured marker values should clearly be evaluated.