Randomized Evaluation of Patients With Stable Angina Comparing Diagnostic Examinations

Inclusion Criteria: * Willing and able to provide a written informed consent; * 40 years or older; * Presentation with symptoms of stable angina (CCS Class I to III) or angina equivalent with or without known CAD; * Planned non-invasive imaging for CAD diagnosis; * Able to tolerate CCTA or SPECT MPI per randomization as required by protocol, to be performed at an ACRIN-qualified facility with a RESCUE-qualified scanner. Exclusion Criteria: * Prior revascularization; * Not suitable to undergo CT with an iodinated contrast agent: * Known allergy-like reaction to contrast media as defined by the American College of Radiology (ACR) (see www.acr.org/SecondaryMainMenuCategories/quality\_safety/contrast\_manual.aspx for reaction definition) or moderate to severe allergic reactions to more than one allergen; * Renal failure, as determined by glomerular filtration rate (GFR) \< 30 mL/min/1.73 m2 based on a serum creatinine level obtained within 28 days prior to registration; * Renal insufficiency at the time of enrollment, as determined by GFR 30 to 60 mL/min/1.73 m2 based on a serum creatinine level obtained within 28 days prior to registration, unless permitted by the institution's policy and/or ACR guidance for risk reduction strategies (see www.acr.org/SecondaryMainMenuCategories/quality\_safety/contrast\_manual.aspx for guidance on contrast selection and pre-treatment strategies); * Atrial fibrillation or significant arrhythmia judged to potentially limit quality of CCTA; * Acute ischemia; * Acute myocardial infarction; * Severe myocardial ischemia: known markedly positive exercise treadmill stress test (ST) \[significant ST segment depressions or hypotensive response during stage I of the Bruce protocol\]; * Unable to suspend respiration for 15 seconds or to follow instructions to do so; * Unstable angina and symptoms refractory to maximal oral and intravenous medical therapy (persistent CCS Class IV); * History of known left ventricular ejection fraction \< 45%; * Pulmonary edema or heart failure unresponsive to standard medical therapy; * Pacemaker; * Valvular heart disease likely to require surgery in the next 18 months; * Congenital heart disease or cardiomyopathy likely to affect prognosis during follow up; * Significant systemic hypertension (blood pressure \> 200/100 mm Hg) unresponsive to medical therapy; * Severe noncardiovascular comorbidity limiting survival (e.g., cancer or other life threatening illness for which the patient is expected to live less than 12 months); * Prior imaging evaluation for this episode of symptoms (e.g., SPECT MPI or CCTA within the previous 72 hours); * BMI \> 40 kg/m2; * Pregnancy or intent to become pregnant (if a female is of childbearing potential-defined as a premenopausal female capable of becoming pregnant-a pregnancy test should be done prior to enrollment).