This is a multicenter (11 centers), prospective, randomized single blind study. This study has a 2-arm design assessing the safety and effectiveness of the Sirolimus-eluting stent CYPHERTM and/or updated version to the bare metal Bx SONICTM stent. A total of 250 patients will be entered in the study and will be randomized on a 1:1 basis. Patients who meet the eligibility criteria will be either randomized to the Sirolimus-eluting stent or the bare metal Bx SONIC stent. The investigator cannot be blind because the outer appearance of the system for the implant of the Sirolimus-eluting stent differs from that of the bare metal stent and will therefore immediately be recognized by the surgeon. However the patient will not know which stent will be implanted. Patients will be followed at 30 days, 9 and 12 months post-procedure, with all patients undergoing repeat angiography at 8 months. Additionally, medical costs associated with the index hospitalization and length of stay, and repeat hospitalizations and costs associated with other relevant medical resource use during the 1 year follow-up period will be collected and analyzed.