Study to Determine the Clinical Significance of Intravascular OCT-NIRAF

Inclusion Criteria: * Participants with stable CAD or acute coronary syndromes undergoing invasive coronary angiography in the MGH cardiac catheterization laboratory * Participant is eligible for PCI * Participants must be over the age of 18 * Participant must be able to give informed consent * Women with childbearing potential must have a negative pregnancy test within seven days prior to the procedure Exclusion Criteria: * CLINICAL EXCLUSION CRITERIA: * Renal insufficiency (GRF\<45 ml/min/1.73m2) * Pregnancy * Acute myocardial infarction: Participants with ST elevation MI will be excluded for at least 72 hours post event. Participants with non-ST elevation MI will be excluded if they have evidence of ongoing ischemia defined as chest pain or new ECG changes in the previous 12 hours and/or rising cardiac biomarker enzymes (e.g., troponin or CKMB) * Evidence of ongoing or active clinical instability, including acute chest pain (sudden onset), cardiogenic shock, unstable blood pressure with systolic blood pressure \<90 mmHg, and severe congestive heart failure (NYHA III or IV) or acute pulmonary edema, * Emergent procedures * Ejection fraction \<= 35% * Clinically significant bleeding within the past 14 days * Any active, serious, life-threatening disease with a life expectancy of less than 12 months * Inability to be evaluated at follow-up * Currently enrolled in another study utilizing OCT imaging, or in an investigational trial that involves a non-ap…