Syncope, a frequent reason for emergency room visits and hospitalization, is a symptom of three major etiological entities: cardiac causes, vaso-reflex causes and orthostatic hypotension. The etiological diagnosis is often uncertain and the prognostic assessment orients the outcome of the patient. The vast majority of syncope management costs are related to hospitalizations. Hospitalization in the immediate aftermath of emergency care is justified by a short-term prognosis. The current relevance of hospitalizations and the prognostic assessment of syncope is questioned.

The improvement of cardiac troponin assay techniques has increased its sensitivity to detect myocardial ischemic conditions, even at the expense of a loss of specificity. Myocardial infarction type 2 is due to an imbalance between needs and oxygen supply to cardiomyocytes at the time of an increase of the first and / or a decrease of the second and is favored by an underlying cardiovascular field fragile. Syncope, because of the low flow that they imply, can be the cause of a type II myocardial infarction on fragile cardiovascular ground.

The study is prospectively conducted in all patients admitted for syncope to assess the actual diagnostic performance of hypersensitive troponin in the syncope risk stratification. The primary benefit is to identify patients at risk of serious cardiac events in the short term. The secondary benefits expected from the study are a decrease in unjustified hospitalizations of patients admitted to the emergency for syncope and thus a decrease in the cost of care.

The validation of the indication of the troponin assay in the stratification of the risk after a syncope passes by its prospective evaluation in a prognostic study.

Inclusion Criteria:

• Patients admitted to the emergency department for syncope as defined by European Society of Cardiology (ESC) recommendations.

Exclusion Criteria:

• Patient under guardianship or safeguard of justice
• Refusal to participate
• Inability to contact the patient again at M1, M3, M6
• Malaise without loss of consciousness (lipothymia)
• Loss of post-traumatic knowledge (after head trauma)
• Loss of consciousness of toxic origin
• Loss of consciousness of confirmed epileptic origin (known epileptic or strongly evocative history with post-critical state)
• Diagnosis performed during the initial emergency assessment of a major adverse cardiovascular event.

Knowing that the number of malaise admitted per year to emergencies is 3972 (2016 data), and 20% are syncope (about 800 syncope per year), recruitment can be done in 12 months.

248 patients admitted for syncope.