Abstract Number: PB0009
Meeting: ISTH 2020 Congress
Background: Dual antiplatelet therapy (DAPT) is standard in acute coronary syndrome because of efficacy in reducing vascular outcomes albeit at an increased bleeding risk.
Aims: To compare effects of clopidogrel-monotherapy with clopidogrel-based DAPT on platelet reactivity and coagulation activation.
Methods: In a randomized, parallel-group, double-blind trial 44 volunteers received a loading dose of clopidogrel (600mg) plus aspirin (100mg) or placebo followed by 6 days of clopidogrel (150mg) plus aspirin (100mg) or placebo. Multiple electrode aggregometry (MEA), the vasodilator-stimulated phosphoprotein (VASP), prothrombin fragment 1.2 (f1.2), d-Dimer, and thromboxane B2(TxB2) were measured in venous blood at different timepoints before first study drug intake and over the course of treatment. Data are given as mean differences (Δmean [95% confidence interval])or geometric mean ratios (GMR [95% confidence interval]) to describe changes in time and differences between groups.
Results: Clopidogrel-based DAPT and clopidogrel-monotherapy comparably decreased adenosine diphosphate-triggered platelet aggregation (MEA-ADP) (Δmean: -37.1 (-44.4; -29.9), p< 0.0001 and -32.2 (-39.8; -24.6), p< 0.0001) and VASP (Δmean: -36.1 (-46.9; -25.3), p< 0.0001 and -43.1 (-54.4; -31.8), p< 0.0001) at 2h. Arachidonic acid-triggered aggregation (MEA-AA) was reduced by clopidogrel-based DAPT and clopidogrel-monotherapy (Δmean: -63.8 (-73.9; -53.8), p< 0.0001 and -24.3 (-34.9; -13.7), p< 0.0001) at 2h. Over 8 days, clopidogrel-based DAPT and clopidogrel-monotherapy comparably affected MEA-ADP and VASP, whereas MEA-AA was significantly stronger influenced by clopidogrel-based DAPT (Δmean: -70.1 (-79.5; -60.7), p< 0.0001 and -21.2 (-31.0; -11.4), p< 0.0001).
Clopidogrel-based DAPT almost entirely eliminated TxB2-generation at 8 days (GMR: 0.03 (0.02; 0.05), p< 0.0001), but clopidogrel monotherapy also reduced TxB2-generationat 8 days (GMR: 0.52 (0.32; 0.86), p=0.01).
Both treatments did not affect f1.2 at 2 hours and 8 days. d-Dimer was slightly reduced by clopidogrel-based DAPT (0.94 (0.89; 1.00), p=0.04) at 2h but not after 8 days. Clopidogrel-monotherapy did not decrease d-Dimer.
Conclusions: Clopidogrel-based DAPT and clopidogrel-monotherapy comparably affect platelet and coagulation activation.
[Boxplots demonstrating the effects of clopidogrel-based DAPT and clopidogrel-monotherapy on platelet aggregation (MEA-ADP, MEA-AA) and VASP]
To cite this abstract in AMA style:
Traby L, Kollars M, Kaider A, Siller-Matula JM, Puhr HC, Steinbrecher O, Eischer L, Wolzt M, Kyrle PA, Eichinger S. Differential Effects of Clopidogrel with or without Aspirin on Platelet Reactivity and Coagulation Activation: A Randomized Placebo-Controlled Trial in Healthy Volunteers [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/differential-effects-of-clopidogrel-with-or-without-aspirin-on-platelet-reactivity-and-coagulation-activation-a-randomized-placebo-controlled-trial-in-healthy-volunteers/. Accessed March 21, 2024.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/differential-effects-of-clopidogrel-with-or-without-aspirin-on-platelet-reactivity-and-coagulation-activation-a-randomized-placebo-controlled-trial-in-healthy-volunteers/