Cor Vasa 2002, 43(10):422-425
Troponins - the main biochemical markers of myocardial injury. A confrontation of international guidelines with the real potential of clinical laboratories
- Ústav klinické biochemie a diagnostiky, Fakultní nemocnice, Hradec Králové, Česká republika
Both international guidelines for the diagnosis of acute coronary syndrome (NACB for biochemistry and ESC/ACC for cardiology) regard troponins as the pivotal biochemical cardiac marker of myocardial injury. This finding is generally recognized as an evidence-based one. Use of troponin I or T is equivalent. The key data of the recommendations are the values of diagnostic cut-off limits, time to response, and the accuracy of measurement accuracy. The paper shows quite clearly that the current status of analytical technology still does not meet the requirements formulated in the data of these recommendations, nor does it provide enough guarantees the recommendations will in fact be adhered to. The main problems include inadequate standardization and the resultant inadequate degree of inter-laboratory comparability of results obtained when using different measuring systems marketed by different manufacturers. Given the current status, it would be naive to assume that the cut-off limits for the different systems used are equivalent. Another problem is the lack of information on how the use of serum or plasma, obtained using different anticoagulants, affects not the results of measurements but, most importantly, also the actual values of diagnostic cut-off limits. Elimination of these problems will require major advances in the process of worldwide standardization. To mitigate these problems, considering the present-day status, which is far from being optimal, it is imperative to establish intensive and constant cooperation of clinicians and laboratory technicians, preferably based on joint guidelines updated as analytical techniques and technology improve. It is also necessary to provide for three-way flow of information among laboratories, clinicians, and manufacturers. In no case it is possible to continue employing current laboratory-based diagnosis of acute coronary syndromes using determinations of catalytic concentrations of the myocardium-non-specific enzymes LD, CK, CK-MB (or even AST), or measurement of weight concentrations of CK MB, whose values are incapable of stratifying the risk of acute myocardial infarction or sudden coronary death.
Keywords: Acute coronary syndrome; Diagnosis; Troponins; Cut-off limits; Standardization
Published: October 1, 2002 Show citation