A Study to Evaluate Safety and Efficacy of the ExcelTM Sirolimus Eluting Stent With a Biodegradable Polymer Versus Sirolimus Eluting Stent With Non-Biodegradable Polymer in the Treatment of Patients With de Novo Coronary Artery Lesions

Inclusion Criteria: 1. Patient \> 18 years of age. 2. Diagnosis of stable angina, unstable angina or silent ischemia (evidence of myocardial ischemia). 3. Positive functional study or reversible change in the electrocardiogram (ECG) consistent with ischemia. 4. Patient must be an acceptable candidate for coronary artery bypass graft (CABG) surgery. 5. Patient must agree to undergo all required follow-up exam- inations. Angiographic Inclusion Criteria: 1. Presence of one or more de novo coronary artery stenosis \> 50% in native coronary arteries that corresponds with the evidence of ischemia. NOTE: In the presence of multiple de novo coronary lesions a maximum of four (4) planned Excel or Cypher stents may be used. 2. The target lesion(s) must be \< 24mm in length and the reference diameter is \> 2.5 mm and \< 3.75 mm (visual estimate). Exclusion Criteria: 1. Patient is pregnant or breast feeding. 2. Patient is allergic or has a contraindication to aspirin, clopidogrel and ticlopidine, heparin and bivalirudin, stainless steel, PLA, contrast media (that can not be adequately pre- medicated), and sirolimus (or its analogues). 3. Patient has evidence of an Acute Myocardial Infarction evidenced by elevation of CK/CK-MB or Troponin per clinical site standards, within 72 hours of the index procedure. 4. Patient is unable to provide informed consent. 5. Patient is participating in another device or drug study that has not reached the primary endpoint of the study. 6. Patient is considered for a DES other than the Excel or the Cypher stents. 7. Patient has a co-morbid condition(s) that could limit the patient's ability to participate in the study, comply with follow- up requirements and impact the scientific integrity of the study. Angiographic Exclusion Criteria: 1. Patient has undergone previous stenting anywhere within the target vessel(s) within the previous 12 months, or will require stenting within the target vessel(s) within 12 months after the study procedure, or has received coronary brachytherapy at anytime. 2. Heavily calcified target lesion(s) which cannot be successfully pre-dilated. 3. Target lesion(s) involves a side branch \>2.5 mm in diameter, or \< 2.5 mm in diameter requiring treatment. 4. Patient has an unprotected Left Main Coronary Lesion with a diameter of \>= 50%. 5. Anticipated use of rotoblator or cutting balloon on target lesion(s).