 This study is designed to evaluate a new approach to the diagnosis of chronic or sub-acute chest pain patients in the out-patient setting. Patients in this study are selected to be low-risk, meaning they are not having an acute or recent heart attack AMI, based on screening blood tests and electrocardiograms EKGs. In addition, these patients have a low or intermediate pre-test likelihood of the coronary artery disease CAD, which means that probability of the CAD based on the available clinical and historical information, does not make a diagnosis of the CAD a certain clinical diagnosis in the particular patient and this, in turn, requires an additional diagnostic work up. 