Acute chest pain is a common diagnostic and management problem that places a considerable burden on emergency departments (EDs). Amongst a large group of patients with a good prognosis exists a small number of individuals harbouring a high risk of potentially fatal recurrent ischaemic events in the short to medium term. Rapid identification of these high risk patients with acute coronary syndrome (ACS) remains a challenge. The detection of a raised cardiac troponin (cTn) is an integral part of the diagnosis of acute myocardial infarction (AMI). However there are numerous causes for a raised troponin in patients presenting to the ED. The diagnosis of AMI requires evidence of a rise and/or fall of cTn in association with clinical evidence of myocardial ischaemia. Few studies have addressed the implications of the use of delta troponin in the ED, where the focus of both rapid identification of patients with an AMI and exclusion of serious pathology is required in a heterogenous population. The presentation will focus on the evidence of use of delta troponin in the ED for the diagnosis of AMI and other conditions. Results from ED-based research will be presented.