The purpose of this study is to evaluate a near-infrared (NIR) spectroscopy system that has been designed to identify the chemical composition of coronary artery plaques in patients undergoing a percutaneous coronary intervention (PCI).

Extensive studies conducted over the past 7 years in autopsy specimens have demonstrated that NIR spectroscopy can identify the plaque structures that are suspected to cause the acute coronary artery syndromes(unstable angina, myocardial infarction, and sudden death).

The application of NIR spectroscopy to identify lipid deposition within coronary arteries has shown promising results in preclinical ex vivo studies (14). Infrared spectra are collected as follows: light of discrete wavelengths from a laser is directed onto the tissue sample via glass fibers. Light scattered from the samples is collected in fibers and launched into a spectrometer. The plot of signal intensity as a function of wavelength can be then used to develop chemometric models to discriminate lipid-rich deposits from non-atherosclerotic tissue, and from atherosclerotic tissue that is predominantly fibrotic and from blood elements. This technique is incorporated into a thin catheter with similar dimensions to an IVUS catheter, and the intracoronary dwell time for analysis is similar to the broad experience with established techniques with proven safety, such as IVUS.

Inclusion Criteria:

• >=18yrs and undergoing elective or non-emergent PCI of a de novo native coronary artery lesion
• Treatment plan (at time of consent and at time of intervention) must be to perform an intervention on no more than 2 lesions, where one is the culprit lesion and the other lesion requires revascularization at the discretion of the treating physician.
• Target lesion should have "low-risk" characteristics(defined by angiography)
• Subject must be able to read, understand and sign an approved informed consent form and follow protocol
• Female subjects of child bearing potential must have a negative serum pregnancy test prior to enrollment

Exclusion Criteria:

• Evidence of Clinical instability in the 6 hours before the procedure, or at any time during the procedure (72 hours stable post-STEMI)
• Angiographically Unsuitable Coronary and/or Lesion Morphology in the culprit vessel.
• A contraindication to anticoagulation or increased risk of bleeding.
• Clinically significant abnormal laboratory findings
• Presence of a drug eluting stent in the artery for experimental study prior to NIR measurement, unless all struts are covered by endothelium as documented by IVUS
• Elective PCI on or through bypass grafts or LIMA grafts
• Allergy or intolerance to aspirin or clopidogrel
• Planned use of laser ablation, rotational ablation, brachytherapy, or atherectomy device
• Enrollment or participation in any other medication trial within the previous 30 days
• Current enrollment participation or enrolled in another clinical trial
• Any other factor that the investigator feels would put the patient at increased risk if participating in the protocol

Technical limits of the prototype device factored into the data set reduction(28 patients).Data made available to evaluate handling of the device(30 patients) could not be prospectively evaluated for the primary endpoint of Spectral Similarity.