Clinical trial NCT01793597: Platelet Reactivity After CABG
Official title: Platelet Activation, Reactivity, and Inflammation After Coronary Bypass Surgery In Patients Treated With Ticagrelor or Clopidogrel
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Acute Coronary Syndrome
Keywords: ticagrelor
Coronary artery bypass surgery
platelet function
receptor binding
platelet reactivity
reversible binding
Lead sponsor: University of Vermont
Sponsor class: OTHER
First posted: 2013-02-15
Enrollment: 18
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: 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.

Brief summary: 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.


Eligibility criteria: 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

Primary outcomes:
measure: reactivity of juvenile platelets
timeFrame: 16-24 hours after CABG
Secondary outcomes:
measure: platelet-leukocyte aggregates
timeFrame: 16-24 hours after CABG
measure: platelet microparticles
timeFrame: 16-24 hours after CABG
measure: cytokine/chemokine array
timeFrame: 16-24 hours after CABG
Other outcomes:
Locations:
city: Burlington
country: United States
facility: University of Vermont Medical Center
state: Vermont
Study officials:
References: