The main objective of this study is to assess the safety and effectiveness of the Cypher™ sirolimus-eluting stent in reducing angiographic in-lesion late loss in patients with an in-stent restenotic native coronary artery lesion.

This is a multicenter (11 sites), non-randomized study. Patients who meet the eligibility criteria will be treated with the Cypher™ sirolimus-eluting stent. All patients will have a repeat angiography at six months post-procedure and will be additionally followed clinically at 1, 6 and 9 months and up to 3 years. The results of this study will be compared with the outcome of the GAMMA I / II as the historical control.

Inclusion Criteria:

1. The patient has an in-stent restenosis of ≥ 60% and < 100% (by QCA online of the MLD compared to the distal reference diameter) in a native coronary artery.
2. The study target lesion can not be located in a vessel containing another lesion requiring treatment. Lesions located in other vessels may be treated with percutaneous revascularization at the time of the procedure, BUT they must be successfully treated prior to the treatment of the study target lesion.

Exclusion Criteria:

1. Unprotected left main coronary disease with ≥ 50% stenosis;
2. Patient previously treated with brachytherapy in any coronary vessel.
3. Target lesion involves bifurcation including a side branch >2.5mm in diameter.
4. The patient sustained a recent (<72 hours) myocardial infarction defined as a serum CK 2x the upper limit of normal and elevated MB or abnormal lab values.