The AtheroRemo-IVUS study aims to investigate the relation of coronary plaque phenotype and vulnerability as determined by intravascular ultrasound and near infrared spectroscopy with genetic profile and novel circulating biomarkers. AtheroRemo-IVUS is a prospective, observational, cohort study of patients who underwent coronary catheterization for acute coronary syndrome or stable angina pectoris. Prior to the catheterization procedure, blood samples were drawn for biomarker measurements and genetic analyses. Subsequent to the catheterization procedure, intravascular ultrasound is performed in a non-culprit coronary artery. In patients who are also participating in the AtheroRemo-NIRS substudy, near-infrared spectroscopy is additionally performed in the same non-culprit vessel. Primary endpoint is the presence of vulnerable plaque as determined by intravascular ultrasound. Secondary endpoint is long-term incidence of major adverse cardiac events. Results from AtheroRemo-IVUS are expected to improve our knowledge on the role of genetic profile and inflammation in the development of atherosclerosis and vulnerable plaques. Furthermore, novel biomarkers and intracoronary imaging techniques will be validated in this study.

Inclusion Criteria:

1. Patients of both sexes, more than 21 years old.
2. Patients with stable angina pectoris (CCS Class 1, 2, 3 or 4) or unstable angina pectoris (Braunwald Class 1-3, B-C) or patients with documented silent ischemia or patients with an acute myocardial infarction (STEMI and NSTEMI).
3. Patients eligible for coronary revascularization in the native coronary artery/arteries.
4. Willing and able to comply with the specified follow-up evaluation.
5. Written informed consent obtained.
6. Flow-limiting stenosis (diameter stenosis ≥50% by QCA or visual estimate) that is held responsible for angina pectoris or acute coronary syndrome
7. The study vessel has not undergone percutaneous coronary intervention in the last 8 months.

Exclusion Criteria:

1. Braunwald class IA, IIA, IIIA (angina caused by non-cardiac illness).
2. Women who are pregnant or women of childbearing potential who do not use adequate contraception.
3. Known allergies to aspirin, clopidogrel bisulfate (Plavix ®), Ticlopdine (Ticlid ®) heparin, stainless steel, copper or a sensitivity to contrast media which cannot be adequately pre-medicated.
4. Previous participation in this study or participation in another study with any investigational drug or device within the past 30 days (study participation ends after completion of the final follow-up.)
5. Life expectancy of less than one year or factors making clinical and/or angiographic follow-up difficult.
6. Planned or being status post coronary bypass surgery.
7. Planned major non-cardiac surgery.
8. Impaired renal function (creatinine >2 mg/dl or >150 umol/L).
9. The subject has a history of bleeding diathesis or coagulopathy.
10. The subject suffered disabling stroke within the past year.
11. 3-vessel coronary artery and/or Left main disease with > 50% stenosis.
12. Minimal lumen diameter <2mm in the segments to be analyzed within the study vessel.
13. Diameter Stenosis >70% or total occlusion of the study vessel.
14. In case the study-vessel has been stented previously (>8 months ago), more than 1/3 proximal of the study vessel (at least 40mm in length) should be available for examination (i.e., outside the length of the stent plus 5mm proximal to the stent).
15. Poor LV function as assessed by Echo or by Angiography.
16. The proximal vessel is moderately to severely tortuous (moderate: 2 bends >75 degrees or one bend >90 degrees) in the segment(s) to be analyzed.
17. Known tendency to coronary vasospasm.

Patients with acute coronary syndrome or stable angina pectoris, referred for percutaneous coronary intervention or coronary angiography