Non-isotope Based Imaging Modalities vs Technetium-99m Single-Photon Emission Computed Tomography(99mTcSPECT)

Obtain a better understanding of the clinical utility of advanced non-isotope-based imaging modalities to detect relevant CAD as potential alternatives to SPECT. Approximately 450 subjects will be enrolled in total. Three groups of about 150 patients per group. Each group will undergo imaging with 2 modalities; Group 1: 99mTcSPECT plus CMR, Group 2: 99mTcSPECT plus CT, Group 3:99mTcSPECT plus stress echocardiography. All 450 patients will undergo standard invasive coronary angiography following completion of non-invasive imaging, except for patients in whom both nuclear and non-nuclear imaging modalities reveal a normal result confirming the absence of significant coronary artery disease (i.e invasive angiography would not be clinically indicated and FFR would be considered to be above 0.8). Thrombolysis in Myocardial Infraction (TIMI) flow will be measured in all patients undergoing angiography, and fractional flow reserve (FFR) will be measured in all patients except those with TIMI flow =0, 1 and 2. All imaging procedures must be completed within 6 weeks. All patients will have a follow-up visit at 6 months after enrollment. During the 6 month follow-up visit major adverse cardiovascular events will be collected and adjudicated by a clinical endpoint committee (CEC).

Inclusion criteria

• clinically indicated request for SPECT
• ability to undergo at least one of three non-nuclear imaging tests; CMR, CT or Stress Echocardiography
• History of recent symptoms suggestive of myocardial ischemia
• High risk for ischemic cardiovascular events

Exclusion criteria

• severely reduced systolic function (LV ejection fraction less than 35%)
• Recent (less than 3 days) acute coronary syndrome including acute myocardial infarction
• contraindications to dipyridamole SPECT including : i)severe reactive airway disease; ii) less than 3 days post Myocardial Infarction - Acute Coronary Syndrome (MI-ACS); iii) high-grade Atrioventricular block (AV block); iv)allergy to dipyridamole or theophylline; v) caffeine within 12 hours; vi) theophylline use within 48 hours; vii) severe claustrophobia; or viii) women who may be pregnant
• kidney dysfunction (i.e estimated Glomerular Filtration Rate (eGFR) less than 45)
• use of investigational drug or device within 30 days of screening visit
• Coronary Artery Bypass Graft(s) surgery (CABG)