Caffeine's Effect on Regadenoson Administration With Single Photon Emission Computed Tomography (SPECT) Myocardial Perfusion Imaging (MPI)

Inclusion Criteria: * Subject must have undergone a previous diagnostic study \[e.g., SPECT, echocardiography, magnetic resonance imaging (MRI), etc.\] for a clinical indication demonstrating evidence of reversible defects in ≥ 1 vascular segment, have had other stress testing within the past 3 months, or the subject's history suggests at least a 50% likelihood of CAD * If the previous diagnostic study shows only 1 reversible defect and it is in segment 17, another reversible defect will need to be present * Subject with CAD must have an intermediate/low-risk for immediate intervention * Subject must ingest caffeinated food or beverages regularly (at least the equivalent of one cup of caffeinated coffee daily) * Subject must agree to not ingest any caffeine or other foods containing methylxanthine at least 24 hours prior to each study visit * Subject must agree to abstain from eating solid food or drinking liquids other than water for at least 30 minutes prior to each study visit and 30 minutes following each study visit Exclusion Criteria: * Subject with documented myocardial infarction (MI) ≤ 30 days prior to enrollment * Subject with history of percutaneous coronary intervention (PCI) ≤ 4 weeks prior to enrollment * Subject with history of coronary artery bypass graft (CABG) ≤ 8 weeks prior to enrollment * Subject has prior history of heart transplantation * Subject has unstable angina, known severe left main coronary artery stenosis, severe heart failure, uncontroll…