Atherosclerotic Coronary Vulnerable Plaque: Correlation With Coronary Artery Calcium

Inclusion Criteria: * Patient is ≥18 years of age * Patient is clinically indicated due to angina, abnormal functional test or other ischemic symptoms to undergo non-emergent cardiac catheterization with IVUS evaluation i.If the patient has not had a cardiac MDCT with CACS meeting the protocol requirements within 3 months prior to the cardiac catheterization, the patient is able to undergo CACS following LipiScan IVUS and NIRS evaluation, prior to any coronary revascularization ii. If the patient has had a cardiac MDCT evaluation with CACS meeting the protocol requirements within 3 months prior to the cardiac catheterization, LipiScan IVUS and NIRS imaging will be completed in at least two (2) major epicardial vessels prior to any coronary revascularization * At least two (2) major epicardial native vessels are suitable for interrogation by LipiScan IVUS imaging and NIRS evaluation, defined as: i.At least 30 mm of vessel that is \> 2.0mm in diameter ii.No other contraindications to imaging * No contraindications for LipiScan IVUS and NIRS evaluation * No contraindications for CACS evaluation by MDCT * Subject must be able to provide informed consent form and comply with the protocol requirements Exclusion Criteria: * Evidence of clinical hemodynamic instability in the 6 hours before either procedure * Prior history of percutaneous coronary intervention (PCI) with stent placement * Prior history of bypass grafts * Female subject that is pregnant or lactating * Any other factor that the investigator feels would put the patient at increased risk or otherwise make the patient unsuitable for participation in the protocol