A Single-center prospective pilot study enrolling chest pain patients. CD 26 measurement will be performed and compared to troponin µs for early triage of these patients. This novel biomarker of myocardial ischemia (CD26) will be measured at the time of first medical contact (T0) and after 30 min simultaneously o troponin Ic.

All patients aged over 18 years with chest pain which may be related to acute coronary syndrome requiring pre hospital medical contact through the Emergency Medical Service.

First objectives: demonstrating the early positivity of CD26 compared to ultra-sensitive troponin.

Inclusion Criteria:

• Subject with compatible symptoms with an acute coronary syndrome, for at least 15 minutes and not older than 3 hours (eg discomfort, tightness or chest pain, pain radiating to the left arm or two arms, pain in the jaw, pain in the back / neck / stomach, breathlessness , cold sweats, nausea / vomiting , dizziness )
• Man or woman,
• Patient Did not receive heparin or low molecular weight heparin (LMWH ) before the initial blood sample ,
• Patient Agreeing to participate in the study and who signed an informed consent

Exclusion Criteria:

• Minor or major patient trust
• Patient Not having signed informed consent (refusal , physical or mental disability ... )
• Patient Who received anticoagulation before carrying blood samples
• Patient With a progressive septic processes , neoplasia undergoing treatment, dialyzed kidney failure, a history of surgery or coronary angioplasty less than six months.
• Transplanted heart, renal or hepatic
• heart attack
• Subject Whose symptoms clearly eliminates acute coronary syndrome ( penetrating trauma, traumatic injury by crushing ... )
• Patient Died between the time of inclusion and arrival in the cardiology intensive care ( SIC )
• Patient Withdrawing consent under study