The cardiac troponins: uses in routine clinical practice. Experiences from GUSTO and other clinical trials

Recent advances in pharmacological and mechanical approaches to acute coronary syndromes have led to rapid changes in the management of patients admitted with acute coronary syndromes. These changes have been mirrored by the appearance of newer highly specific biochemical markers of myocardial damage particularly the cardiac troponins. When new biochemical markers become available it is the responsibility of the clinical chemist to evaluate them critically in terms of sensitivity, specificity, efficiency and analyzer precision, in the rigid setting of quality control that laboratories practise, and to compare them with other markers. When the data are shown to Clinical Cardiologists with supporting statements such as 'useful management tool' and 'can be used for early diagnosis of Myocardial Infarction', a different set of questions may need to be answered. The 'So what?' response is most frequent and is the most important hurdle that these newer biochemical markers have to overcome to convince physicians to change their current practice. This presentation will review the results of studies that have examined the potential clinical usefulness of the cardiac troponins with respect to diagnosis and risk stratification of patients admitted with suspected acute coronary syndromes. Any troponin variable that survives the 'so what' question has one further major hurdle to overcome. This is the requirement to inform physicians what different therapeutic strategies they should follow if the variable is present. Available clinical trial evidence about differing management options for patients according to their troponin status will be reviewed and outline management algorithms will be presented. Many questions remain unanswered and these will be included at the time points where they may be relevant.