Use of biochemical markers in acute coronary syndromes

This paper presents evidence and suggestions from the IFCC Committee on "St andardization of Markers of Cardiac Damage" (C-SMCD) on the use of biochemi cal markers for the triage diagnosis of acute coronary syndromes. There is general agreement that both 'early' and 'definitive' biochemical markers of myocardial damage are necessary and that these assays must be available wi th a turnaround time of 1 h or less. Currently, myoglobin is the marker tha t most effectively fits the role as an 'early' marker, whereas 'definitive' markers are cardiac troponins. Since the sensitivity of the initial electr ocardiogram is only 50 % for detecting myocardial infarction, the use of bi ochemical markers may significantly contribute to the early diagnosis and b ecome relevant when the electrocardiogram is not diagnostic. In addition, n ew sensitive biochemical markers, particularly the cardiac troponins, are p resently the best to detect the presence of minor myocardial cell damage. W ith regard to this, two decision limits are probably needed for the optimal use of troponins: a low abnormal value suggesting the presence of myocardi al damage and a higher value suggesting the diagnosis of myocardial infarct ion according to traditionally used criteria. Properly designed studies sho uld be performed to establish limits for each commercially available tropon in assay. Finally, it is recognized that there is no need for the use of an y biochemical marker when the clinical diagnosis is unequivocal, other than for diagnosing reinfarction, estimating the infarct size, and monitoring t hrombolytic therapy.