Investigation of the Athero-Protective Effects of Clopidogrel
Condition: Coronary Artery Disease
MeSH terms: Coronary Artery Disease; Myocardial Ischemia; Coronary Disease
Study type: Interventional
Phase: Phase 4

Summary: 
      The investigators would like to investigate whether clopidogrel will help lower the level of
      harmful markers in patients with coronary artery disease, and at the same time will help
      increase the cells that are useful in repairing the damaged blood vessels. The investigators
      will give half of the patients clopidogrel and the other half a sugar pill, placebo, and
      check the levels of these markers and helpful cells in each group. At the same time the
      investigators will check how well these patient's blood vessels work using ultrasound imaging
      of the forearm to see how blood vessels relax and tonometry to see how stiff the patient's
      blood vessels are. After 6 weeks of drug therapy, the patients will switch to the other drug
      and these same tests will be performed after an additional 6 weeks of therapy. The drug taken
      by the patient will not be known to the patient or the researchers. The patients will
      continue on their prescribed medical therapy during the duration of the 12 week study.
    

Detailed description: 
      Blockages in the blood vessels of the heart are caused by atherosclerosis. Atherosclerosis is
      the main cause for chest pain and heart attacks. Gradual narrowing of the vessels of the
      heart caused by blockages causes chronic symptoms, such as chest pain. Those with these
      findings often have a cardiac catheterization to detect these blockages. Additionally these
      patients may have an angioplasty or stent placed to help relieve these symptoms. With this
      angioplasty/stent procedure, patients are placed on the drug clopidogrel to help prevent
      clots from forming and narrowing of the blood vessels. Clopidogrel is a blood thinner that
      prevents clots from forming similar to an aspirin, but is more powerful and effective.
      Markers, or substances, have been identified that cause worsening of the blockages in the
      blood vessels of the heart. Many of these substances have been shown to decrease with the use
      of clopidogrel. This occurs separately from clopidogrel's ability to prevent clots.
      Endothelial progenitor cells, or EPCs, come mostly from the bone marrow and is helpful in
      repairing damage to the lining of the blood vessels of the heart. The EPCs help balance out
      the damage incurred in the blood vessels from those harmful markers. Several other drugs
      commonly used in heart disease have recently been shown to improve EPCs function. With this
      in mind, it is important to understand more of clopidogrel's function. A decrease in markers
      that cause worsening of the blockages, and an increase in the number of cells that will help
      repair damaged blood vessels of the heart is important in avoiding future chest pain and
      heart attacks. This may be how clopidogrel is currently protecting patients from developing
      new blockages. The investigators would like to investigate whether clopidogrel will help
      lower the level of harmful markers in patients with coronary artery disease, and at the same
      time will help increase the cells that are useful in repairing the damaged blood vessels. The
      investigators will give half of the patients clopidogrel and the other half a sugar pill,
      placebo, and check the levels of these markers and helpful cells in each group. At the same
      time the investigators will check how well these patient's blood vessels work using
      ultrasound imaging of the forearm to see how blood vessels relax and tonometry to see how
      stiff the patient's blood vessels are. After 6 weeks of drug therapy, the patients will
      switch to the other drug and these same tests will be performed after an additional 6 weeks
      of therapy. The drug taken by the patient will not be known to the patient or the
      researchers. The patients will continue on their prescribed medical therapy during the
      duration of the 12 week study.
    

Intervention name(s): Clopidogrel; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): Clopidogrel 75 mg PO qday for 6 weeks; Placebo PO qday for 6 weeks
Other intervention name(s): Plavix
Intervention MeSH terms: Clopidogrel
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Basic Science