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Platelet Reactivity After CABG

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ClinicalTrials.gov Identifier: NCT01793597
Recruitment Status : Completed
First Posted : February 15, 2013
Last Update Posted : September 22, 2015
Information provided by (Responsible Party):

February 13, 2013
February 15, 2013
September 22, 2015
May 2013
September 2015   (Final data collection date for primary outcome measure)
reactivity of juvenile platelets [ Time Frame: 16-24 hours after CABG ]
We will use flow cytometry to identify juvenile platelets and assess their likelihood to activate in response to a submaximal concentration of agonist.
Same as current
Complete list of historical versions of study NCT01793597 on ClinicalTrials.gov Archive Site
  • platelet-leukocyte aggregates [ Time Frame: 16-24 hours after CABG ]
    We will identify the prevalence of platelet-leukocyte aggregates - a marker of platelet activation in vivo
  • platelet microparticles [ Time Frame: 16-24 hours after CABG ]
    We will quantify the prevalence of platelet microparticles, reflecting platelet activation in vivo
  • cytokine/chemokine array [ Time Frame: 16-24 hours after CABG ]
    We will quantify the concentration of common cytokines and chemokines.
Same as current
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Platelet Reactivity After CABG
Platelet Activation, Reactivity, and Inflammation After Coronary Bypass Surgery In Patients Treated With Ticagrelor or Clopidogrel
Patients who have a heart attack are regularly treated with either clopidogrel or ticagrelor. In a large clinical trial, treatment with ticagrelor before coronary bypass surgery (CABG) was associated with a lower risk of death than treatment with clopidogrel. The reason for this difference cannot be explained on the basis of the study. One possible explanation is that the reversible binding of ticagrelor is advantageous because when new platelets are released, they are inhibited by the drug. Because clopidogrel binds irreversibly it cannot redistribute. The investigators will recruit patients who are scheduled for surgery after an acute coronary syndrome who have been treated with either ticagrelor or clopidogrel. After the patient provides informed consent, the investigators will review their medical record,record information and on the day after surgery the investigators will take one sample of blood. That blood will be analyzed for evidence of platelet activation (platelet microparticles, and platelet-leukocyte aggregates), the reactivity of young platelets, and the concentration of inflammatory cytokines. The investigators hypothesize that the evidence of platelet activation (platelet microparticles and platelet-leukocyte aggregates) and the reactivity of young platelets will be less in patients who have been treated previously with ticagrelor.
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Observational Model: Cohort
Time Perspective: Prospective
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Retention:   Samples Without DNA
Platelets and leukocytes will be evaluated acutely. Plasma will be stored for cytokine and chemokine analysis.
Non-Probability Sample
Patients with acute coronary syndrome who based on clinical indications require urgent CABG. CABG is scheduled for clinical indications within 48 hours. Previous treatment with clopidogrel or ticagrelor.
Acute Coronary Syndrome
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  • clopidogrel
    previous treatment with clopidogrel
  • ticagrelor
    previous treatment with ticagrelor
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
September 2015
September 2015   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Acute coronary syndrome, CABG, within 48 hours of last dose of clopidogrel or ticagrelor, treatment with aspirin

Exclusion Criteria:

  • Treatment with an antiplatelet agent other than aspirin, clopidogrel, or ticagrelor, Acute or chronic hematologic disorder including a preoperative Hgb less than 10 g/dl or platelet count less than 100,000/mm3, Moderate or severe renal insufficiency (glomerular filtration rate less than 60 ml/min), Active infection, Active malignancy, Unable/unwilling to provide informed consent
Sexes Eligible for Study: All
18 Years and older   (Adult, Senior)
Contact information is only displayed when the study is recruiting subjects
United States
Not Provided
Not Provided
David J. Schneider, MD, University of Vermont
University of Vermont
Not Provided
Not Provided
University of Vermont
September 2015