The purpose of this study is to determine whether exercise testing can detect an obstruction in a coronary artery, and, thereby, can avoid performing a coronary imaging in some cases. Patients with a suspicion of coronary artery disease perform an exercise test on an exercise bike with increasing load. EKG, blood pressure, and other parameters are monitored. Patients benefit also of either a cardiac CT scan or a coronary angiography to establish whether they really have coronary obstruction.