The aim of this study is to define the best prognostic strategy for patients presenting suspected acute CORONARY syndrome, between MSCT and stress echocardiography.

Patients presenting with a suspected acute CORONARY syndrome is based on the interrogation, the realization of an electrocardiogram (ECG) and 2 dosages of the cardiac troponin at some hours of interval. However, the ECG and the troponin are frequently normal and this does not absolutely eliminate the diagnosis. In that case, it is at present recommended to practise an effort ECG or a stress imaging, such as echocardiography. Several studies estimated the diagnostic exactness of stress echography for patients presenting a recent chest pain without modification of the ECG nor a rise of the troponin with a sensibility from 71 to 86% and a specificity from 91 to 98%. Recently, several teams estimated the interest of multislice computed tomography (MSCT) in the same population. The MSCT sensibility reported by 2 teams is promising because was found between 91 and 100%. On the other hand, the specificity was appreciably less good : between 76 and 82%. The negative predictive value to MSCT was excellent : between 97 and 100%.The aim of this work is to compare the diagnostic exactness between stress echography and MSCT for patients presenting with a suspected acute coronary syndrome without modification of the ECG nor rise of the troponin. It is about a prospective monocentric diagnostic study concerning 400 patients. The primary end point is the proportion report of true positives in MSCT with regard to stress echocardiography (the main diagnosis is the coronarography). The secondary end points include the proportion of false positives, the non interpretable or non contributory examination rate and especially the proportion of unwanted events in 6 months for the negative patients in both examinations according to a combined criteria including death, myocardial infraction (MI), percutaneous CORONARY intervention (PCI), coronary artery bypass graft (CABG) or readmission for chest pain with coronarography visualizing a stenosis greater than 50 %.

Inclusion Criteria:

• chest pain < 24 hours
• normal ECG
• normal troponin I

Exclusion Criteria:

• ECG evolution
• troponin I evolution
• hemodynamic instability
• rhythmic instability
• allergy to iodized contrast products
• Creatinin > 150 micromol/L
• venous capital absence
• auricular fibrillation