A Study to Assess Regadenoson Administration Following an Inadequate Exercise Stress Test as Compared to Regadenoson Alone for Myocardial Perfusion Imaging (MPI) Using Single Photon Emission Computed Tomography (SPECT)

Inclusion Criteria:

- Subjects referred for an exercise or pharmacologic stress test SPECT MPI procedure
for the evaluation of coronary artery disease (CAD) are eligible for study
participation. Subjects referred for pharmacologic stress should have a reasonable
potential of attempting exercise stress. Subject must have one of the following:

- a. Past ischemia on any prior imaging stress test without invasive intervention
on the artery subtending this territory

- b. Subject with known CAD who have symptoms similar to previous ischemic
symptoms, or recent onset of symptoms or recently worsened symptoms suggestive
of ischemia

- c. Diamond Forrester estimated pretest probability of CAD of ≥ 50%

- d. History of most recent coronary artery bypass surgery or most recent
percutaneous coronary intervention (PCI) > 10 years (patients who are > 30 days
but less than 10 years post coronary artery bypass graft (CABG) or PCI can be
included if they meet criteria a, b, or e)

- e. Previously demonstrated 100% occlusion by invasive coronary or computed
tomography (CT) angiography without successful intervening revascularization as
these foods may alter regadenoson effects

Exclusion Criteria:

- Subject has a clinically significant illness, medical condition, or laboratory
abnormality

- Female subject who is pregnant or lactating

- Subject is on dialysis for end stage renal disease or has a history of glomerular
filtration rate (GFR) < 15 mL/min (calculated using MDRD [Modification of Diet in
Renal Disease] formula)

- Subject has a history of coronary revascularization by either PCI or CABG within 1
month prior to the rest myocardial perfusion imaging (MPI)

- Subject has a pacemaker or an implantable cardioverter defibrillator (ICD)

- Subject has a history of acute myocardial infarction (MI) or high risk unstable
angina within 30 days prior to the rest MPI or has had cardiac transplantation

- Subject has uncontrolled hypertension at any point on Visit 2 prior to exercise
testing (i.e., systolic blood pressure (SBP) ≥ 180 or diastolic blood pressure (DBP)
≥ 95 mmHg on two consecutive measurements while at rest).

- Subject has severe aortic stenosis or hypertrophic cardiomyopathy with obstruction or
has decompensated congestive heart failure

- Subject has a history of severe respiratory disease including: asthma, chronic
obstructive pulmonary disease (COPD) or other bronchospastic reactive airway disease
or who is on 24-hour continuous oxygen