The Dual Antiplatelet Therapy Study (DAPT Study)

Subjects with ischemic heart disease due to stenotic lesions in either native coronary
arteries or coronary artery bypass grafts undergoing percutaneous coronary intervention
(PCI) with stent placement and no contraindications to prolonged dual antiplatelet therapy
are eligible to be enrolled in the study.

All enrolled subjects will undergo PCI with stent placement. All enrolled subjects will be
treated with either an FDA-approved drug eluting stent(s) (DES) or an FDA-approved bare
metal stent(s) (BMS) (per their respective Instructions for Use) and assigned to 12 months
of open label FDA-approved thienopyridine treatment in addition to aspirin. Operators will
select the thienopyridine according to the package insert. Thienopyridine treatment dose
will be according to the standard of practice and prescribing information for the selected
medication. Aspirin treatment will be 75-325 mg for the first 6 months after the procedure
and 75-162 mg subsequently, to be continued indefinitely. All DES or BMS subjects who are
treated with 12 months of dual antiplatelet therapy post index procedure and who are event
free per protocol will be eligible for randomization to either placebo (12 m DAPT Study arm)
or an additional 18 months of thienopyridine treatment (30 m DAPT Study arm). Both arms will
continue aspirin therapy.

Up to four (4) separate post-market approval studies will be allowed to incorporate the
randomized design of the DAPT Study for a subset of subjects who may then be contributed for
the DAPT Study analyses.

Inclusion Criteria (Enrollment):

1. Subject is > 18 years of age.

2. Subjects undergoing percutaneous intervention with stent deployment (or has w/in 24
hours).

3. Subjects without known contraindication to dual antiplatelet therapy for at least 30
months after enrollment and stent implantation.

4. The subject has consented to participate and has authorized the collection and
release of his medical information by signing the "Patient Informed Consent Form".
The informed consent will be valid for the duration of the trial or until the subject
withdraws.

Inclusion Criterion (Randomization at 12 months):

1. Subject, at 12 months, is free from death, MI, stroke, repeat coronary
revascularization, major bleeding, and stent thrombosis and has been compliant with dual
antiplatelet therapy following stent implantation.

Exclusion Criteria (Enrollment):

1. Index procedure stent placement with stent diameter <2.25 mm or >4.0 mm.

2. Pregnant women.

3. Planned surgery necessitating discontinuation of antiplatelet therapy within the 30
months following enrollment.

4. Current medical condition with a life expectancy of less than 3 years.

5. Concurrent enrollment in another device or drug study whose protocol specifically
excludes concurrent enrollment or that involves blinded placement of a DES or BMS
other than those included as DAPT Study devices. The subject may only be enrolled in
the DAPT Study once.

6. Subjects on warfarin or similar anticoagulant therapy.

7. Subjects with hypersensitivity or allergies to one of the drugs or components
indicated in the Instructions for Use for the device implanted.

8. Subjects unable to give informed consent.

9. Subject treated with both DES and BMS during the index procedure.

Exclusion Criteria (Randomization at 12 months):

1. Pregnant women.

2. Subject switched thienopyridine type or dose within 6 months prior to randomization.

3. Percutaneous coronary intervention or cardiac surgery between 6 weeks post index
procedure and randomization.

4. Planned surgery necessitating discontinuation of antiplatelet therapy within the 21
months following randomization.

5. Current medical condition with a life expectancy of less than 3 years.

6. Subjects on warfarin or similar anticoagulant therapy.