Platelet Reactivity In Patients With Nuisance Bleeding On A Thienopyridine

Study Overview
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Brief Summary
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The objective is to describe and quantify levels of platelet reactivity in three different cohorts of patients taking thienopyridine: patients who report nuisance bleeding, patients who report alarming bleeding, and patients who report no nuisance or alarming bleeding. The investigators hypothesize that patients with nuisance or alarming bleeding events on maintenance thienopyridine therapy will have lower levels of platelet reactivity than patients without nuisance or alarming bleeding on thienopyridine therapy.

Official Title
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Platelet Reactivity In Patients With Nuisance Bleeding On A Thienopyridine

Conditions
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Platelet Aggregation, Bleeding

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients 18 years or older from both genders Underwent PCI within the last year Taking maintenance dose of clopidogrel 75 mg once a day or prasugrel 10 mg once a day for at least five days Exclusion Criteria: Known allergies to aspirin, clopidogrel, or prasugrel. Use of a glycoprotein (GP)IIb/IIIa inhibitor within 8 hours of the blood draw. Patient known to be pregnant or lactating Patient with known history of anemia, thrombocytopenia, bleeding disorder, or currently active bleeding On warfarin therapy at the time of blood draw Known blood transfusion within the preceding 10 days of the blood draw Patients treated with non-steroidal anti-inflammatory drugs (NSAIDS, not to include aspirin) within the previous 5 days Any significant medical condition that, in the investigator's opinion, may interfere with the patient's optimal participation in the study.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| nuisance bleeding<br> | |
| alarming bleeding<br> | |
| maintenance therapy<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| platelet reactivity | Level 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. | post percutaneous coronary intervention (PCI) while still on clopidogrel | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Platelet reactivity | Platelet reactivity, as measured with the VerifyNow P2Y12 assay, expressed as platelet reactivity units (PRUs) Platelet reactivity, as assessed with the Vasodilator Stimulated Phosphoprotein (VASP) assay, which measures percentage platelet reactivity inhibition by flow cytometry of the VASP-P protein. Aspirin resistance, as assessed with the VerifyNow aspirin resistance assay, which measures aspirin resistance (ARUs). | post PCI while still on clopidogrel |