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)

The purpose of this study is to compare Multidetector Computed Tomography (MDCT) and Single Photon Emission Computed Tomography (SPECT) stress myocardial perfusion imaging (MPI) with regadenoson in order to detect the presence or absence of reversible defects.

All participants will be randomized to one of two imaging sequences: rest/stress SPECT on Day 1 followed by stress/rest MDCT on Day 2 or stress/rest MDCT on Day 1 followed by rest/stress SPECT on Day 2. All stress scans will involve the injection of regadenoson as the pharmacologic stress agent.

Eligibility Criteria:
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 Screening
* Subject has a history of a clinically significant illness (other than CAD), medical condition, or laboratory abnormality, which would preclude participation in the study
* Subject has renal dysfunction demonstrated by a glomerular filtration rate (GFR) \< 45 mL/min (calculated using Cockroft-Gault formula Note: Subjects with a GFR 45-60 mL/min will undergo a hydration procedure
* Female subject who is pregnant, lactating or of childbearing potential that refuses to use a medically acceptable form of contraception until the Telephone Follow up Visit is complete
* Female subject has a positive pregnancy test prior to randomization
* Subject has a history of second or third degree heart block or sinus node dysfunction unless the subject has a functioning pacemaker
* Subject has symptomatic hypotension (temporary and reversible conditions that no longer exist are allowed)
* Subject is allergic or intolerant to aminophylline, nitroglycerin or metoprolol
* Subject is allergic or intolerant to regadenoson or any of its excipients
* Subject is unable or unwilling to comply with the procedure schedule
* Subject has previously enrolled in this study or was enrolled in another regadenoson study sponsored by Astellas
* Subject has atrial fibrillation or significant arrhythmias which may result in decreased image quality for the imaging studies (CT and SPECT)
* Subject has high heart rate (\> 65 beats per minute) and contra-indications to administer beta-blockers (severe chronic obstructive pulmonary disease (COPD) or asthma, second and third degree atrioventricular block)