The main objective of this study is to demonstrate the superiority or non-inferiority of the sirolimus-eluting Bx VELOCITY® stent compared to intravascular brachytherapy in patients with in-stent restenotic native coronary artery lesions.

Inclusion Criteria:

• 1. The patient has an in-stent restenosis of > 50% (by subjective angiographic determination of the minimal luminal diameter compared to the distal reference diameter) within a native coronary artery which has previously undergone stent placement ( 4 weeks). Lesions must meet ISR Classification I-III.

  2. The patient has a history, signs of, or laboratory studies that suggest coronary ischemia attributable to the target stenosis. The diagnosis of angina pectoris is defined by Canadian Cardiovascular Society Classification (CCS I, II, III, or IV) OR unstable angina pectoris (Braunwald Classification B&C, I-II) OR patients with documented silent ischemia;

  3. The study target lesion must be located in an in-stent restenotic native coronary artery measuring > 2.75mm and 3.5mm in diameter and > 15mm and 40mm in length to allow treatment with a maximum of three 18mm stents. The target lesion must have undergone coronary interventional treatment > 4 weeks previously. Patients with one or more prior percutaneous coronary interventions at the target lesion are acceptable candidates.

  4. The vessel 1cm distal to the target lesion is > 2.5mm in diameter;

  5. Ejection Fraction must be > 40%;

  6. The study target lesion cannot be located in a vessel containing a second lesion requiring treatment at the time of the procedure.

  7. Male or non-pregnant female patients > 18 years of age inclusive. NOTE: Females of child-bearing potential must have a negative pregnancy test (urine or serum) prior to enrollment and must use birth control for 6 months.

Exclusion Criteria:

1. The study target lesion has definite or possible thrombus present by angiographic criteria.
2. The 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.
3. Impaired renal function (Serum creatinine > 2.0mg/dl);
4. The patient has unstable angina classified as Braunwald III B or C, or is having peri infarction angina.
5. The left ventricular ejection fraction is < 40%.
6. The target vessel has previously sustained a perforation.
7. Totally occluded vessel (TIMI 0 level);
8. Prior stent within 5mm of target lesion;
9. There is a total occlusion of the restenosed-stent (ISR Classification IV) prior to the interventional procedure.
10. Has an ostial target lesion;
11. Significant (> 50%) in-stent restenoses proximal or distal to the target lesion that might require revascularization or impede runoff;