Platelet Reactivity in Patients on a Thienopyridine and Awaiting Coronary Artery Bypass Grafting (Serial CABG)

This study is ongoing, but not recruiting participants.
Sponsor:
Information provided by (Responsible Party):
Medstar Research Institute
ClinicalTrials.gov Identifier:
NCT01406483
First received: July 22, 2011
Last updated: August 8, 2014
Last verified: April 2013
  Purpose

The primary objective of this exploratory cohort study is to describe levels of platelet reactivity in patients on a thienopyridine awaiting coronary artery bypass grafting (CABG).


Condition Intervention
Complication of Coronary Artery Bypass Graft
Peri-operative Hemorrhage or Hematoma
Post Operative Bleeding
Other: Platelet reactivity assessment

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: Platelet Reactivity in Patients on a Thienopyridine and Awaiting Coronary Artery Bypass Grafting

Resource links provided by NLM:


Further study details as provided by Medstar Research Institute:

Primary Outcome Measures:
  • Serial levels of platelet reactivity, as assessed with the Chrono-log Lumi-Aggregometer [ Time Frame: Duration of hospital stay; average hospital stay of 1 week ] [ Designated as safety issue: No ]
    Serial levels of platelet reactivity, as assessed with the Chrono-log Lumi-Aggregometer, which measures levels of light transmittance after stimulation with ADP to estimate levels of platelet aggregation

  • Perioperative rates of bleeding complications [ Time Frame: Duration of hospital stay; average hospital stay of 1 week ] [ Designated as safety issue: No ]

    Perioperative rates of bleeding complications:

    1. need for reoperation because of bleeding
    2. need for perioperative red blood cell transfusion (units of packed red blood cells)
    3. rates of TIMI, GUSTO, and nuisance bleeding
    4. quantity of postoperative drainage (mL)


Secondary Outcome Measures:
  • Serial levels of platelet reactivity, as assessed with the VerifyNow P2Y12 assay [ Time Frame: Duration of hospital stay; average hospital stay of 1 week ] [ Designated as safety issue: No ]
    Serial levels of platelet reactivity, as assessed with the VerifyNow P2Y12 assay, which measures platelet reactivity units (PRUs)

  • Serial levels of platelet reactivity, as assessed with the Vasodilator Stimulated Phosphoprotein (VASP) assay [ Time Frame: Duration of hospital stay; average hospital stay of 1 week ] [ Designated as safety issue: No ]
    Serial levels of platelet reactivity, as assessed with the Vasodilator Stimulated Phosphoprotein (VASP) assay, which measures percentage of platelet reactivity inhibition (PRI) by flow cytometry of the VASP-P protein


Estimated Enrollment: 100
Study Start Date: September 2010
Estimated Study Completion Date: July 2016
Estimated Primary Completion Date: February 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
CABG Other: Platelet reactivity assessment
Platelet reactivity, as measured by the Chrono-log Lumi-Aggregometer, VerifyNow P2Y12 assay, and Vasodilator Stimulated Phosphoprotein (VASP) flow cytometry assay.

Detailed Description:

The recent emergence of platelet reactivity testing as a potential option for evaluating the degree of platelet inhibition promises to add another level of understanding to our concept of CABG-related bleeding. There is an emerging literature that links high levels of platelet reactivity with adverse clinical events, primarily in patients on clopidogrel.

For example, studies of the VerifyNow P2Y12 platelet function assay have shown that Platelet Reactivity Units (PRU) > 235-240 in patients on clopidogrel therapy appears to predict cardiovascular events.15,16 There is a paucity of literature, however, on the use of platelet reactivity testing to predict bleeding events and complications. In other words, if excessively high levels of platelet reactivity predict ischemic events, do excessively low levels of platelet reactivity predict bleeding events? This is an especially relevant question, given the emergence of prasugrel as a therapeutic option.

The investigators therefore propose an exploratory cohort study of patients receiving a thienopyridine (clopidogrel or prasugrel) and undergoing CABG, in order to describe levels of platelet reactivity in such patients by using a variety of platelet function tests.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  1. Patients ≥ 18 years old from both genders.
  2. Taking maintenance thienopyridine therapy within 5 days of surgery OR received a loading dose of thienopyridine therapy within 48 hours of surgery for CABG.
  3. Referred for CABG (which is scheduled to be performed during the current admission).

Exclusion Criteria:

  1. Known allergies to aspirin, clopidogrel, or prasugrel.
  2. Use of a glycoprotein (GP) IIb/IIIa inhibitor within 8 hours of initial platelet reactivity testing.
  3. Patient known to be pregnant or lactating.
  4. Patient with known history of bleeding diathesis or currently active bleeding.
  5. Platelet count <100,000/mm the day of initial blood draw.
  6. Hematocrit <25% the day of initial blood draw.
  7. On warfarin therapy at the time of initial blood draw.
  8. Known blood transfusion within the preceding 10 days of the blood draw.
  9. Patients treated with non-steroidal anti-inflammatory drugs (NSAIDS) within the previous 5 days.
  10. Plan for patient to be discharged before undergoing CABG.
  11. Any significant medical condition that, in the investigator's opinion, may interfere with the patient's optimal participation in the study.
  Contacts and Locations
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  More Information

No publications provided

Responsible Party: Medstar Research Institute
ClinicalTrials.gov Identifier: NCT01406483     History of Changes
Other Study ID Numbers: Serial CABG
Study First Received: July 22, 2011
Last Updated: August 8, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by Medstar Research Institute:
Platelet reactivity
CABG
Perioperative and in hospital bleeding

Additional relevant MeSH terms:
Blood Loss, Surgical
Hemorrhage
Postoperative Hemorrhage
Intraoperative Complications
Pathologic Processes
Postoperative Complications

ClinicalTrials.gov processed this record on October 23, 2014