Study of Near Infrared Spectroscopy (NIRS) and Intravascular Ultrasound (IVUS) Combination Coronary Catheter

Inclusion Criteria: * \>=18yrs of age. * diagnosed with stable angina pectoris or documented silent ischemia * scheduled for elective, non-emergent cardiac catheterization * able to read, understand, and provide written informed consent * \>=1 obstructive stenosis (\>50%DS by visual estimate)in a major native coronary artery * clinically indicated treatment plan includes placement of a guidewire into the target artery. * target artery has a \>=30mm segment with a reference vessel diameter \>=2.5mm * target artery has a \>50%DS luminal narrowing Exclusion Criteria: * Subject unwilling or unable to provide written informed consent. * Subject unwilling to comply with protocol * Subject is pregnant * Subject is of childbearing potential without negative pregnancy test. * Subject received prolonged CPR within 2 weeks of enrollment procedure * Subject is intubated. * Subject is diagnosed with an acute coronary syndrome. * Subject has severe persistent hypertension. * Subject has renal dysfunction or insufficiency. * Subject has an abnormal platelet count. * Subject has low hemoglobin levels. * Subject has active liver disease or dysfunction. * subject diagnosed with acute pulmonary edema or congestive heart failure. * Subject diagnosed or suspected to have acute myo-, peri-, or endo- carditis, cardiac tamponade, or dissected aortic aneurysm. * Subject has significant valvular heart disease, cardiomyopathy, or congenital heart disease. * Subject has history of intracranial bleeding or aneurysm. * Subject has a history of stroke that precludes the use of routine antithrombotic agents during PCI? * Subject has known hypercoagulable state, coagulopathy, or abnormal bleeding. * subject has family history of coagulopathy or bleeding diathesis. * subject has undergone PCI in the last 30days. * subject enrolled or participating in pharmaceutical study in last 30 days. * subject enrolled or participating in medical device treatment study in last 30 days. * subject has obstructive LMCA disease. * subject has multivessel CAD that requires additional treatment in a separate procedure with 30days of enrollment. * subject has unprotected left main disease. * three vessel intervention is required during enrollment procedure. * target artery is the left circumflex artery. * target artery is accessed through a vein or arterial graft. * target artery is tortuous * target artery contains segments of severe calcification * target artery has \>2 serial obstructions exceeding 50%DS. * target artery has an aneurysm or suspected aneurysm. * target artery has \<=1 TIMI flow. * target lesion is \>99% DS. * target lesion is severely calcified * target lesion has angiographic characteristics of thrombus. * target lesion has angiographic characteristics of ulceration. * target lesion has inclusion of a side branch greater than 1mm. * target lesion is located in a vessel segment with \>4.0mm reference vessel diameter.