Chest pain is one of the main common causes of ED [1] presentation and admission. In the USA database AHRQ News and Numbers, based on data in Emergency Department Visits for Adults in Community Hospitals from Selected States, 2005 [2], chest pain was the reason for more than 1.6 million visits to EDs in 23 states in the USA in 2005. Ultimately, only 345000 patients were hospitalized for observation or treatment. An ACS is a high-risk situation and must be eliminated as a possible diagnosis before the patient leaves the ED. While in some situations there is no real doubt (clear ST-segment elevation myocardial infarction, clear non-cardiac cause, etc.), in a number of cases it is impossible to confirm or exclude the diagnosis, especially in the first hours after admission to the ED, without additional tests. However, it is crucial to begin effective treatment as early as possible, due to the high risk of complications in patients with undetected unstable angina. On the other hand, beginning an aggressive anticoagulant therapy in all patients in the ED at risk of an ACS is not a good alternative, due to the relatively high risk of complications in a large cohort and the fact that only a small number of patients would gain a possible benefit from such therapy, as reported in this article [2] and in other registries.