Evaluation of Sirolimus-Eluting, Heparin-Coated CoCr Stent in the Treatment of de Novo Coronary Artery Lesions in Small Vessels(EVOLUTION)

Inclusion Criteria: 1. The patient must be minimum 18 years of age; 2. Diagnosis of angina pectoris as defined by Canadian Cardiovascular Society Classification (CCS I, II, III, IV) OR unstable angina pectoris (Braunwald Classification B\&C, I-II-III) OR patients with documented silent ischemia; 3 Treatment of one lesion in a native coronary artery. The treated lesion will be the one with the highest % diameter stenosis by visual estimate. Additional study stents may be used for procedural complications such as dissections. Multivessel treatment is permissible in non-target vessels; however, additional lesions may only be treated with commercial stents. If other non-target vessels are treated with commercial stents during the index procedure, they must be successfully treated prior to the study lesion; 4\. The target lesion is \>/=2.0 mm and \</=2.5mm in diameter (visual estimate); 5\. The target lesion can be covered with a single 18mm stent; 6\. Target lesion stenosis is \>50% and \<100% (TIMI I) (visual estimate); Exclusion Criteria: 1. Patient has experienced a Q-wave or non-Q-wave myocardial infarction with documented total CK\>2 times normal within the preceding 24 hours and the CK and CK-MB enzymes remain above normal at the time of treatment; 2. Target lesion is due to in-stent restenosis; 3. Ejection fraction 30%; 4. Totally occluded vessel (TIMI 0 level); 5. Impaired renal function (creatinine \> 3.0 mg/dL);