Evaluation of patients presenting with chest pain in the emergency department: Where do troponins fit in?

Abstract

Patients presenting to the Emergency Department with symptoms consistent with possible acute cardiac ischaemia, particularly chest pain, are one of the most common patient groups presenting to Emergency Departments in the developed world. These patients account for approximately 10 % of Emergency Department presentations and up to 25 % of hospital admissions (Goodacre et al., Heart 91:229-230, 2005). Up to 90 % of these patients do not have a final diagnosis of an acute coronary syndrome (ACS). This large group of patients consumes considerable hospital resources with extensive investigations being common practice. Cardiac troponin is very important in this assessment process because traditionally, the large number of hospital admissions has been driven by a need to measure circulating cardiac troponin on arrival at hospital and then again at a delayed period afterwards. Historically, the second blood sample has been approximately 6 h or later after arrival or symptom onset. This timeframe has been used because early research on cardiac troponins suggested that troponin rises due to myocardial necrosis from acute myocardial infarction (AMI) were not reliably detectable until 6-12 h after symptom onset (Cooper et al., Chest pain of recent onset: assessment and diagnosis of recent onset chest pain or discomfort of suspected cardiac origin. London: National Clinical Guideline Centre for Acute and Chronic Conditions. http://publications. nice.org.uk/chest-pain-of-recent-onset-cg95. Accessed 15 Mar 2011, 2010).