Effectiveness Study of Single Photon Emission Computed Tomography (SPECT) Versus Positron Emission Tomography (PET) Myocardial Perfusion Imaging

The purpose of this study is to compare pharmacologic stress myocardial perfusion PET with pharmacologic stress myocardial perfusion SPECT in a near-simultaneous, head-to-head comparison in the same patient. The investigators hypothesize that pharmacologic stress myocardial perfusion PET will prove superior to pharmacologic stress myocardial perfusion SPECT as a first-line diagnostic test for higher-risk patients with known coronary artery disease (CAD) who present with symptoms consistent with possible worsening of their CAD.