[Redefinition of myocardial infarction--relevance of biomarkers]

Myocardial infarction (MI) as an acute and life-threatening complication of coronary heart disease is one of the most frequent causes of death in Germany. Therefore, diagnosis, risk stratification and treatment of acute MI are of great clinical relevance. Specific recommendations concerning diagnosis of acute MI can be found in current guidelines of the European Society of Cardiology (ESC) and the German Cardiac Society, as well as in a consensus document "Universal definition of myocardial infarction", which has been published at the end of 2007. Here, cardiac markers, namely cardiac troponins, play a central role as a criterion for the diagnosis of myocardial infarction. Moreover, cardiac troponins provide prognostic information and are of great value for risk stratification of patients. Measurement of creatine kinase CK-MB is an alternative to troponin measurement, but is only recommended, if troponins are not available. As a cutoff value for cardiac biomarkers the 99th percentile of a healthy reference population has been defined. However, assays that are used for routine testing require adequate precision. Besides established biomarkers, several novel markers have been evaluated in clinical studies in recent years. Especially B-type natriuretic peptides (BNP and NT-proBNP) and C-reactive protein (CRP) have gained great interest and sufficient data has been gathered, justifying clinical application of these novel markers. As a consequence, BNP/NT-proBNP and CRP are mentioned in the current guidelines of the ESC as appropriate biomarkers for risk stratification. The clinical relevance of other novel biomarkers remains uncertain and necessitates further studies.