Platelet Reactivity After CABG
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.
Acute Coronary Syndrome
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||Platelet Activation, Reactivity, and Inflammation After Coronary Bypass Surgery In Patients Treated With Ticagrelor or Clopidogrel|
- reactivity of juvenile platelets [ Time Frame: 16-24 hours after CABG ] [ Designated as safety issue: No ]We will use flow cytometry to identify juvenile platelets and assess their likelihood to activate in response to a submaximal concentration of agonist.
- platelet-leukocyte aggregates [ Time Frame: 16-24 hours after CABG ] [ Designated as safety issue: No ]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 ] [ Designated as safety issue: No ]We will quantify the prevalence of platelet microparticles, reflecting platelet activation in vivo
- cytokine/chemokine array [ Time Frame: 16-24 hours after CABG ] [ Designated as safety issue: No ]We will quantify the concentration of common cytokines and chemokines.
Biospecimen Retention: Samples Without DNA
Platelets and leukocytes will be evaluated acutely. Plasma will be stored for cytokine and chemokine analysis.
|Study Start Date:||May 2013|
|Study Completion Date:||September 2015|
|Primary Completion Date:||September 2015 (Final data collection date for primary outcome measure)|
previous treatment with clopidogrel
previous treatment with ticagrelor
Please refer to this study by its ClinicalTrials.gov identifier: NCT01793597
|United States, Vermont|
|University of Vermont Medical Center|
|Burlington, Vermont, United States, 05401|