Outpatients scheduled to undergo cardiac catheterization and coronary angiography for the specific indication of inconclusive or indeterminate stress tests will be considered for this study. Patients will be initially screened by their cardiologist for the presence of inclusion/exclusion criteria, as well as pre-test and post-test likelihood of CAD.16, 17 All patients must have undergone a stress (exercise or pharmacologic) test within the past 3 months.