[Determination of cardiac troponins for diagnosis of 'acute myocardial infarct']

Abstract

The diagnosis of 'myocardial infarction' was recently redefined by a commission of European and American cardiologists. The main element of the new definition is a raised serum level of heart-specific troponin (T or I). In healthy adults virtually no cardiac troponin is demonstrable, so that every rise of the level of the heart-specific troponin in the blood means that there is myocardial damage. An infarction during a coronary bypass operation and myocardial damage during skeletomuscular injury can be diagnosed almost faultlessly by a troponin assay. A raised troponin level in acute coronary ischaemia is associated with a raised mortality risk. However, even when the level is normal, a risk of cardiac complications is present. For the diagnosis of a recurrent infarction during a developing infarction, determination of the peak level of the creatine kinase muscle brain mass (CK-MBmass) is most appropriate. Also, the value of including troponin in the existing rule-out protocols has not yet been proven. Now that most Dutch hospitals shortly will be capable of troponin assays, cardiologists and clinical chemists should consider the implementation of this assay in clinical practice.