Considerations for early acute myocardial infarction rule-out for emergency department chest pain patients: the case of copeptin

The evaluation of patients admitted at the emergency department (ED) for chest pain is challenging and involves many different clinical specialists including emergency physicians, laboratory professionals and cardiologists. The preferable approach to deal with this issue is to develop joint protocols that will assist the clinical decision-making to quickly and accurately rule-out patients with non life-threatening conditions that can be considered for early and safe discharge or further outpatient follow-up, rule-in patients with acute coronary syndrome and raise the degree of alert of the emergency physicians on non-cardiac life-threatening emergencies. The introduction of novel biomarkers alongside the well-established troponins might support this process and also provide prognostic information about acute short-term or chronic long-term risk and severity. Among the various biomarkers, copeptin measurement holds appealing perspectives. The utility of combining troponin with copeptin might be cost-effective due to the high negative predictive value of the latter biomarker in the rule-out of an acute coronary syndrome. Moreover, in the presence of a remarkably increased concentration (e.g., more than 10 times the upper limit of the reference range), to reveal the presence of acute life-threatening conditions that may not necessarily be identified with the use of troponin alone. The aim of this article is to review current evidence about the clinical significance of copeptin testing in the ED as well as its appropriate placing within diagnostic protocols.