• myocardial infarction

Public information campaigns have gone to great lengths to emphasise that a suspected myocardial infarction is a medical emergency requiring immediate medical attention. In the UK, the message is simple, ‘Time is Muscle’—dial 999. Highly skilled call handlers perform the challenging task of telephone triage to determine the urgency of response and the rapid dispatch of medical personnel. While standardised triage questions for chest pain are used to help make an informed judgement regarding the clinical severity, it is widely appreciated that the accuracy of these medical dispatching systems is very low and this results in an excessive deployment of emergency medical responders to mitigate any potential harm to patients.1 Indeed, even when senior medical input is involved in the triage decision-making, myocardial infarction only accounts for one in nine of chest pain call-outs.2 In the prehospital setting, emergency medical services are aware of the modest sensitivity (approximately 80%) of an early triage assessment to safely rule out myocardial infarction,3 hence the high rate of transfers to hospital for early biomarker analysis. This simple pathway of dial 999—emergency medical services assessment—immediate hospital transfer is rightly considered the gold standard for achieving a timely assessment and early intervention to minimise the complications of ischaemia and subsequent infarction. However, despite the call for immediate medical attention being a critical part in initiating the ‘chain of survival’, there is a paucity of data regarding this prehospital decision-making. Importantly, does a deviation from …