Randomized Study Comparing Endeavor With Cypher Stents (PROTECT)

Inclusion Criteria: 1. Patient is \> 18 years of age (or minimum age as required by local regulations). 2. The patient has consented to participate and has authorized the collection and release of his medical information by signing the "Patient Informed Consent Form". 3. All lesions requiring interventions (target lesions - one to a maximum of four) in one or more native coronary arteries are amendable for implantation of one or more Endeavor® Zotarolimus Eluting Coronary Stent System or Cypher® Sirolimus-eluting Coronary Stent\*. 4. Patient indication, lesion length and vessel diameter of the target lesion(s) are according to the 'Indications for Use' as mentioned in the 'Instructions for Use' that comes with every Endeavor® Zotarolimus Eluting Coronary Stent System and Cypher® Sirolimus-eluting Coronary Stent. Patients should qualify for both systems before randomization\*. 5. The patient is willing and able to cooperate with study procedures and required follow up visits. Exclusion Criteria: 1. Women with known pregnancy or who are lactating. 2. Planned elective surgery necessitating discontinuation of clopidogrel within the regular planned period of clopidogrel administration. 3. Patients expected not to be compliant with the anti-platelet and/or anticoagulation therapy regimen. 4. Previous brachy-therapy. 5. Previous implantation of a drug eluting stent. 6. Previous implantation of a bare metal stent in the preceding year. 7. Simultaneous or planned intervention other non cardiac vessels including but not limited to renal artery or carotid artery. 8. Current medical condition with a life expectancy of less than 3 years. 9. Manifest acute severe heart failure (Killip class III-IV). 10. The patient is currently, and during the first 3 years of the PROTECT trial, participating in another investigational device or drug study that clinically interferes with the PROTECT-study endpoints; or requires coronary angiography or other coronary artery imaging procedures. The patient may only be enrolled in the PROTECT-study once. 11. Patients with medical conditions that preclude the follow-up as defined in the protocol or that otherwise limits participation in this study. 12. Patients on warfarin or similar anti-coagulant therapy. 13. Patients with hypersensitivity or allergies to one of the drugs or components indicated in the Instructions for Use of either stents. 14. Patients who are judged to have a lesion that prevents complete inflation of an angioplasty balloon. 15. Patients in whom anti-platelet and/or anticoagulation therapy is contraindicated. 16. Transplant patients.