Can help in risk stratification

Despite a fall in the age adjusted prevalence of cardiovascular disease in the developed world,1 the number of patients presenting with chest pain is rising. Greater public awareness of the importance of chest pain has lowered the threshold for seeking medical help, while improvements in our ability to manage acute coronary syndromes necessitate prompt and accurate identification of ischaemic cardiac pain. Most patients who present to accident and emergency departments will have non-cardiac pain and others, with ischaemic pain, will be at low risk of serious adverse events in the short term. In contrast, many of those at high risk have no diagnostic clinical or electrocardiographic findings at presentation (about 50% of patients ultimately diagnosed as having an acute myocardial infarction, and 65% of those with unstable angina, present with non-diagnostic electrocardiograms).2 The major challenge is therefore determining the risk of an individual patient.

There are two components to such risk. “Acute risk” is determined by the volume and severity of ischaemic myocardium (usually reflected in electrocardiographic changes) and the extent of myocardial injury (indicated by troponins and cardiac enzymes). “Prognostic risk” is influenced by prior cardiac damage, confounding …