Intravascular Near Infrared Spectroscopy (NIRS) Bifurcation - Lipid Core Plaque Shift Study

Inclusion Criteria: * Subject must be \>=40yrs * Subject must provide written informed consent. * Subject must be diagnosed with stable or unstable angina pectoris, or documented silent ischemia * Subject must be scheduled for elective or non-emergent percutaneous coronary intervention * Angiographic evidence of a bifurcation lesion with the following characteristics: * Native coronary artery * De novo coronary stenosis at the bifurcation site * Bifurcation Medina class 1,1,0 or 1,0,0 or 0,1,0 * Main vessel stenosis \>50%, with the stenotic lesion in close proximity (≤2mm) to the side branch ostium, by visual estimate. * Side branch diameter ≥ 2.0mm by visual estimate. * Side branch without significant stenosis (\<30% stenosis) * LipiScan catheter optical tip must cross lesion without the need for pre-dilatation Exclusion Criteria: * Subject is pregnant or nursing * Renal insufficiency (Creatinine \>2.0mg/dL) * Left ventricular ejection fraction \<25% by visual estimate. * Known allergy to contrast media that cannot be medically managed. * Acute ST segment elevation myocardial infarction (STEMI) that has not been stabilized. * Any condition or symptom that in the investigator's opinion may adversely alter the risk profile of this study for the subject. * Target lesion is dilated prior to first LipiScan imaging. * Subject experiences procedural complication that precludes clear post angioplasty imaging of the target lesion.