Platelet Reactivity After CABG
This study has been completed.
First Posted: February 15, 2013
Last Update Posted: September 22, 2015
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Information provided by (Responsible Party):
David J. Schneider, MD, University of Vermont
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.
||Observational Model: Cohort
Time Perspective: Prospective
||Platelet Activation, Reactivity, and Inflammation After Coronary Bypass Surgery In Patients Treated With Ticagrelor or Clopidogrel
Primary Outcome Measures:
Biospecimen Retention: Samples Without DNA
Secondary Outcome Measures:
- 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.
Platelets and leukocytes will be evaluated acutely. Plasma will be stored for cytokine and chemokine analysis.
| Study Start Date:
| Study Completion Date:
| Primary Completion Date:
||September 2015 (Final data collection date for primary outcome measure)
previous treatment with clopidogrel
previous treatment with ticagrelor
Information from the National Library of Medicine
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|Ages Eligible for Study:
||18 Years and older (Adult, Senior)
|Sexes Eligible for Study:
|Accepts Healthy Volunteers:
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, CABG, within 48 hours of last dose of clopidogrel or ticagrelor, treatment with aspirin
- 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
Information from the National Library of Medicine
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01793597
|University of Vermont Medical Center
|Burlington, Vermont, United States, 05401 |
University of Vermont
||David J. Schneider, MD, Professor Of Medicine, Director of Cardiology, University of Vermont
History of Changes
|Other Study ID Numbers:
||February 13, 2013
||February 15, 2013
|Last Update Posted:
||September 22, 2015
Keywords provided by David J. Schneider, MD, University of Vermont:
Coronary artery bypass surgery
Additional relevant MeSH terms:
Acute Coronary Syndrome
Platelet Aggregation Inhibitors
Purinergic P2Y Receptor Antagonists
Purinergic P2 Receptor Antagonists
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs