A Study of Regadenoson in Subjects Undergoing Stress Myocardial Perfusion Imaging (MPI) Using Multidetector Computed Tomography (MDCT) Compared to Single Photon Emission Computed Tomography (SPECT)

Inclusion Criteria: * Male subjects must be ≥ 45 years of age * Female subjects must be ≥ 50 years of age * Subject has met at least one of the following three criteria: * has a suspected (clinical impression) or known diagnosis of coronary artery disease (CAD) with typical angina that has been referred from nuclear cardiology lab schedule or cardiac computed tomography (CT) schedule * has stable symptoms with possible elective catheterization procedure scheduled and where further imaging may be beneficial; * has known CAD from a previous invasive coronary angiography (ICA) performed more than 12 weeks prior to screening who now present with new cardiac symptoms * Subject has been referred for a clinically indicated myocardial perfusion imaging procedure or Cardiac CT procedure for suspected moderate or high risk CAD * Subject must abstain from eating and drinking 30 minutes prior and 30 minutes post study drug administration * Subject must abstain from smoking 3 hours prior and 8 hours post study drug administration * Subject must abstain from any intake of methylxanthine-containing foods and beverages within 12 hours prior to Day 1 visit through the Day 3 Follow-Up Visit, as these foods may alter regadenoson effects. Subject is able to safely abstain from theophylline use for 12 hours prior to study drug administration Exclusion Criteria: * Subject is concurrently participating in another drug study or has received an investigational drug within 30 days prior to S…