Platelet Reactivity After CABG

NCT01793597 | Completed

• 1 other identifier: ISSBRIL0095
• Study Type: observational
• Target: 18
• Locations: 1 country
• Sites: 1

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.

Conditions

Acute Coronary Syndrome

Keywords

ticagrelor; Coronary artery bypass surgery; platelet function; receptor binding; platelet reactivity; reversible binding

Outcome Measures

Primary Outcomes (1)

• reactivity of juvenile platelets

  We will use flow cytometry to identify juvenile platelets and assess their likelihood to activate in response to a submaximal concentration of agonist.

  16-24 hours after CABG

Secondary Outcomes (3)

• platelet-leukocyte aggregates

  16-24 hours after CABG

• platelet microparticles

  16-24 hours after CABG

• cytokine/chemokine array

  16-24 hours after CABG

Study Arms (2)

clopidogrel

previous treatment with clopidogrel

ticagrelor

previous treatment with ticagrelor

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• 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.

You may qualify if:

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

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Vermont: lead

Study Sites (1)

University of Vermont Medical Center

Burlington, Vermont, 05401, United States

Location

Biospecimen

Retention: SAMPLES WITHOUT DNA

Platelets and leukocytes will be evaluated acutely. Plasma will be stored for cytokine and chemokine analysis.

MeSH Terms

Conditions

Acute Coronary Syndrome

Condition Hierarchy (Ancestors)

Myocardial Ischemia; Heart Diseases; Cardiovascular Diseases; Vascular Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor Of Medicine, Director of Cardiology

Study Record Dates

• First Submitted: February 13, 2013
• First Posted: February 15, 2013
• Study Start: May 1, 2013
• Primary Completion: September 1, 2015
• Study Completion: September 1, 2015
• Last Updated: September 22, 2015

Record last verified: 2015-09

Locations

US (1)