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Platelet aggregation in response to ADP is highly variable in normal donors and patients on anti-platelet medication

Eimear Dunne, Karl Egan, Siobhán McFadden

    Clinical Chemistry and Laboratory Medicine
    |November 13, 2015
    PubMed

    Insights

    Current guidelines may misclassify platelet inhibition in patients. Many healthy individuals and those on aspirin alone show adequate P2Y12 inhibition, suggesting current thresholds need re-evaluation for personalized antiplatelet therapy.

    Area of Science:

    • Cardiology
    • Pharmacology
    • Hematology

    Background:

    • P2Y12 inhibitors are crucial post-percutaneous coronary intervention.
    • High on-treatment platelet reactivity correlates with adverse outcomes, but guided therapy lacks proven benefit.
    • Limited data exists on pre-treatment platelet aggregation response to ADP.

    Purpose of the Study:

    • To characterize platelet aggregation responses to 20 μM ADP using light transmission aggregometry (LTA).
    • To evaluate platelet reactivity in patients on antiplatelet therapy and healthy volunteers before initiating P2Y12 inhibition.

    Main Methods:

    • Light transmission aggregometry (LTA) assessed platelet aggregation.
    • Study included 201 patients on dual antiplatelet therapy, 98 on aspirin alone, and 47 healthy volunteers.
    • Adenosine diphosphate (ADP) was used as the agonist at a concentration of 20 μM.

    Main Results:

    • Consensus guidelines define <57% platelet aggregation to ADP as adequate P2Y12 inhibition.
    • Seven healthy donors and 38 patients on aspirin alone exhibited aggregation responses below 57%.

    Conclusions:

    • 15% of healthy donors and 38% of patients on aspirin alone met the <57% aggregation threshold.
    • Current guidelines may overestimate therapeutic response in certain populations before P2Y12 inhibitor initiation.
    Abstract

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