Patients with new or worsening chest pain suggesting acute coronary syndromes need treating as an emergency. Rapid assessment is crucial but difficult. Patients with acute chest pain now represent 20% or 30% of all emergency medical admissions, yet less than one third of these will have acute coronary syndromes (acute myocardial infarction or unstable angina).¹ The majority thus do not have significant coronary heart disease. There are approximately 600 000 unnecessary admissions each year in the UK. If adequately investigated, on the basis of rule out algorithms, admission could be avoided. However, up to 2% of acute myocardial infarctions are mistakenly sent home with perhaps a 25% case fatality rate and a high risk of medicolegal problems.^2–4 Any effective scheme would potentially save substantial NHS resources and reduce stress for patients, carers and staff.¹

It is important to emphasise the social context. This is a continuous spectrum ranging from patients who never present grading imperceptibly into patients who present as emergencies. The trigger for such presentation represents the final step in a complex pathway commencing with the patient's perception of symptoms, illness behaviour, family and social norms, advice from significant others, level of education, availability of primary care support, access to accident and emergency (A&E) and response of A&E staff. Although the incidence of coronary heart disease …