Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Double-blind, Randomized Study of Clopidogrel 75 mg/d vs Placebo, on a Background of ASA 75-100 mg/d,in Peripheral Arterial Disease (PAD) Patients Receiving a Unilateral Below Knee Bypass Graft.
Brief Summary: Primary objective:

To evaluate whether clopidogrel 75 mg o.d. versus placebo (on a background of ASA 75-100 mg/d) will lead to an increased rate of primary patency, limb salvage and survival, in patients receiving a below knee bypass graft for the treatment of PAD.

Secondary objectives:

Comparison, between the two treatment groups, of :

* Primary patency,
* Assisted primary patency,
* Cardiovascular death / myocardial infarction / stroke / any amputation above the ankle.
* Ankle Brachial Pressure Index (ABPI) changes from baseline


Options:
A: Inclusion Criteria:

1. Among consecutive patients treated with DES, event-free patients who survived at least the first 12 months without nonfatal MI or repeat revascularization
2. The patient or guardian agrees to the study protocol and the schedule of clinical follow-up, and provides informed, written consent, as approved by the appropriate Institutional Review Board/Ethical Committee of the respective clinical site.

Exclusion Criteria:

1. Contraindication to antiplatelet therapy (aspirin or clopidogrel)
2. Non-cardiac co-morbid conditions are present with life expectancy \<1 year or that may result in protocol non-compliance (per site investigator's medical judgment).
3. Patients who are actively participating in another drug or device investigational study, which have not completed the primary endpoint follow-up period.
4. Concurrent bleeding diathesis or major bleeding history requiring discontinuation of antiplatelet drugs.
5. Patients with left main stem stenosis (\>50% by visual estimate) or left main stenting
6. Concomitant disease requiring long-term use of clopidogrel (stroke, peripheral vascular disease, significant carotid a. disease, etc)
B: Inclusion Criteria:

* Patients presenting with ST elevation, left bundle branch block or ST depression within 24 hours of the onset of the symptoms of suspected acute MI

Exclusion Criteria:

* clear indications for, or contraindications to, any of the study treatments
C: Inclusion Criteria:

* Coronary artery disease including stable angina, unstable angina, acute non-ST elevation myocardial infarction and acute ST elevation myocardial infarction
* Age 20 years of older
* Patients with typical chest pain or evidences of myocardial ischemia (e.g., stable, unstable angina, silent ischemia and positive functional study or reversible changes in the electrocardiogram (ECG) consistent with ischemia
* Patients with signed informed consent
* Lesion and stent length for ACS and DM subgroup : Length of single lesion \< 24 mm and, Summation of total length of all inserted DES in 3 vessel \< 60 mm
* Lesion and stent length for ACS and DM subgroup : Length of single lesion \< 24 mm and, Summation of total length of all inserted DES in 3 vessel \< 60 mm
* Lesion and stent length for long lesion subgroup : Length of single stent per single lesion \> 28 mm and, Summation of total length of all inserted DES in 3 vessel ≤ 90 mm, Possible overlapping stent
* Lesion and stent length for short lesion subgroup : Length of single lesion \< 24 mm and, Summation of total length of all inserted DES in 3 vessel \< 60 mm
* Significant coronary artery stenosis (\>50% by visual estimate) considered for coronary revascularization with stent implantation
* Reference vessel diameter of 2.5 to 4.0 mm by operator assessment
* Lesion success (30% or less residual stenosis by visual assessment over the entire stent length, with TIMI-3 flow and no more than an NHLBI type B peri-stent dissection

Exclusion Criteria:

* Contraindication to anti-platelet agents \& bleeding history within prior 3 months
* Known hypersensitivity or contraindication to any of the following medications: Heparin, Aspirin, Clopidogrel, limus related drug
* Prior history of the following presentations : Cerebral vascular accident (not including transient ischemic attack, Peripheral artery occlusive diseases, Thromboembolic disease, Stent thrombosis
* Severe hepatic dysfunction (3 times normal reference values)
* Significant renal dysfunction (Serum creatinine \> 2.0 mg/dl)
* Significant leukopenia, neutropenia, thrombocytopenia, anemia, or known bleeding diathesis
* Cardiogenic shock
* LVEF \< 40%
* Pregnant women or women with potential childbearing
* Life expectancy 3 year
* Overlapped DESs(only long lesion subgroup is possible overlapping)
* Left main disease requiring PCI
* Bifurcation lesion with 2-stent technique
* Target lesions with in-stent restenosis at the stented segment of DES or BMS
* Lesions with chronic total occlusion
* History of PCI with DES
* In-stent restenosis lesion
D: Inclusion Criteria: A patient is eligible for inclusion in the study 2-4 days after surgery if all the following criteria are fulfilled:

* Informed consent obtained;
* Chronic background treatment with daily ASA, whatever the dose, started at least 4 weeks before surgery. A window of a few days without ASA before surgery is acceptable, according to local practice. Post-randomization use of ASA must be between 75 and 100 mg/day.
* Unilateral below knee bypass graft (i.e. the distal anastomosis is below the level of the knee joint) for atherosclerotic PAD within the previous 4 days;
* Demonstration of initial patency of the index graft by an objective measurement (e.g. intra-operative Doppler scanning, flow measurement, angiography, Duplex scanning) during bypass surgery, or between surgery and the time of randomization;
* No clinical evidence of graft occlusion at time of randomization.

Exclusion criteria :

PAD medical/surgical history

* Onset of PAD symptoms before the age of 40 years
* Non-atherosclerotic vascular disease (e.g. Buerger's disease, popliteal entrapment syndrome)
* Patient receiving aorto-bifemoral, iliac-femoral or crossover (femoral-femoral) grafts, or undergoing peripheral transcutaneous angioplasty (PTA), with or without stenting, during the same surgery.

Medical history related to bleeding risk

* Current active bleeding at surgical site
* Withdrawal of an epidural catheter less than 12 hours before randomization
* Current active bleeding or increased risk of bleeding, such as severe hepatic insufficiency, proliferative diabetic retinopathy, peptic ulceration, bleeding diathesis or coagulopathy
* Peptic ulceration within 12 months of randomization
* Previous or current intracranial hemorrhage or hemorrhagic stroke, or any previous stroke for which the diagnosis of hemorrhagic stroke cannot be excluded
* Any history of severe spontaneous bleeding such as gastrointestinal bleeding, gross hematuria, intraocular bleeding

Other medical conditions

* Previous disabling stroke (severe cerebral deficit such that the patient is bedridden or demented)
* NYHA Class IV heart failure
* Uncontrolled hypertension: Systolic Blood Pressure (SBP) \> 180 mm Hg, or Diastolic Blood Pressure (DBP) \> 100 mm Hg

Answer: D