Acute coronary syndrome (ACS) is a major public health problem and its diagnosis remains a challenge for the emergency physician. The European Society of Cardiology recommends a troponin dosage and renew it if necessary during any suspicion of ACS. However, the criteria leading to initiate a diagnostic procedure during chest pain are imprecise. The fear is, on the one hand, to miss a potentially vital diagnosis and, on the other hand, to expose a large number of patients to unnecessary examinations.

The CARE rule (also known as HEAR score) seems to streamline this first step. It assigns a value of 0 to 2 using 4 items: Characteristic of pain, Age, Risk factors and Electrocardiogram (ECG). The search for an ACS is not justified if the sum of the points is <2 (negative rule) and, inversely, a troponin determination must be carried out if the sum is > 1 (positive rule).

The aim of the study is to demonstrate the safety and interest of the CARE rule associated with the HEART score to streamline ACS's diagnostic approach to thoracic pain in emergencies departments.

Data collected in this study are not anticipated to be published in a data repository. However, data will be shared per requested need to researchers, upon presentation of a structured protocol, when approved by the competent ethic committee and approved by the steering committee.

Inclusion Criteria:

• Admission to an Emergency Department participating in the study
• Non-traumatic chest pain
• Age greater than or equal to 18 years
• Patient's consent (oral for France, written for Belgium)

Exclusion Criteria:

• 30 days follow-up not possible
• ST-segment Elevation Myocardial Infarction (STEMI) on admittance ECG
• Chest pain formally reported to a diagnosis other than an ACS before inclusion (e.g., pneumothorax, pleurisy, etc.)
• Troponin assay performed prior to inclusion (less than 24 hours old)
• Patient referred by another care structure (excluding primary medicine)
• Patient already included in study still in follow-up period
• Pregnant, breastfeeding or parturient patient,
• Patient deprived of liberty by judicial or administrative decision,
• Patient undergoing psychiatric care under duress,
• Patient subject to a legal protection measure,
• Patient unable to give free and informed consent.