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Increased expression of platelet P-selectin and formation of platelet–leukocyte aggregates in blood from patients treated with unfractionated heparin plus eptifibatide compared with bivalirudin

https://doi.org/10.1016/j.thromres.2005.07.020Get rights and content

Abstract

Introduction

Platelet–leukocyte aggregates have been implicated in atherogenesis. This study was designed to determine the influence in vivo of a direct thrombin inhibitor, bivalirudin, compared with unfractionated heparin (UFH) plus the GP IIb–IIIa inhibitor eptifibatide (E) on platelet reactivity, the formation of platelet–leukocyte aggregates, and leukocyte activation.

Materials and methods

Blood was taken before and after percutaneous coronary intervention (PCI) from 60 patients randomized to UFH + E (n = 26) or bivalirudin (n = 34). Platelet function and the formation in vivo of platelet–monocyte aggregates (PMA) and platelet–neutrophil aggregates (PNA) were assessed with the use of flow cytometry. Myeloperoxidase (MPO) elaborated during leukocyte activation was measured by ELISA.

Results

Compared with those treated with bivalirudin, patients treated with UFH + E exhibited a 45% decrease in the capacity of platelets to bind fibrinogen (p = 0.006) but a 2-fold increase in platelet surface expression of P-selectin (p = 0.04) in samples taken from the coronary ostium before PCI. Platelet–leukocyte aggregation in vivo was greater (PMA = 2-fold, p = 0.04; PNA = 3-fold, p = 0.006) with UFH + E as was the concentration in blood of MPO (1.5-fold, p = 0.007).

Conclusions

Increased platelet surface expression of P-selectin, augmented platelet–leukocyte aggregation in vivo, and consequent activation of leukocytes was seen before PCI in blood from patients treated with UFH + E compared with bivalirudin. Benefits associated with decreased platelet aggregation when PCI is performed with UFH plus GP IIb–IIIa inhibition may be partially offset by increased platelet–leukocyte aggregation.

Section snippets

Methods

The institutional review board approved the protocol. All patients provided written informed consent. Eligible patients included adult men and women in whom performance of PCI was clinically indicated. Patients were ineligible if they had received abciximab during the preceding week or eptifibatide or tirofiban within the past 48 h; had a contraindication to UFH, eptifibatide or bivalirudin; or were pregnant or breastfeeding. Patients with and without diabetes mellitus were randomized

Characteristics of patients studied

We studied 60 patients of whom 34 were randomized to bivalirudin and 26 to UFH + E. Their clinical characteristics are shown in Table 1. Most of the patients had stable symptoms of coronary artery disease, with cardiac catheterization performed as an elective procedure. In those with unstable angina, catheterization was performed during their admission for unstable angina. Thirty three percent had diabetes mellitus. Most procedures involved PCI of a single vessel. Two patients in the UFH + E group

Platelet–leukocyte aggregates

To determine whether the increased propensity of platelets to express P-selectin on their surfaces had functional implications, we quantified the presence of platelet–neutrophil (PNA) and platelet–monocyte (PMA) aggregates in coronary blood before and after PCI. A greater prevalence of PNA and PMA was evident in patients treated with UFH + E compared with bivalirudin (Fig. 3). Similar to the case with expression of P-selectin the greatest difference was apparent shortly after initiation of

Influence of clopidogrel

An additional analysis was performed to determine whether pretreatment with clopidogrel altered the influence of either of the two treatment regimens studied. Table 2 shows the results for platelet function, prevalence of platelet–leukocyte aggregation and the concentration of MPO with respect to pretreatment with clopidogrel. Pretreatment with clopidogrel attenuated differences in platelet function and platelet–leukocyte aggregation seen with the 2 anti-thrombotic regimens before and

Discussion

In this comparison of the effect of UFH + E compared with bivalirudin in vivo, we observed greater agonist-induced expression of P-selectin in whole blood samples obtained before PCI from patients treated with UFH + E. The functional significance of the increased platelet reactivity was suggested by an increased prevalence in vivo of platelet–leukocyte aggregates and evidence of greater activation of leukocytes in those treated with UFH + E compared with bivalirudin. We obtained blood from the

Acknowledgements

The authors thank Mary Lord, RN, for her expert assistance. The study was supported by a grant from The Medicine Company.

References (42)

  • A. Aggarwal et al.

    Decreased platelet reactivity in blood anticoagulated with bivalirudin or enoxaparin compared with unfractionated heparin: implications for coronary intervention

    J Thromb Thrombolysis

    (2002)
  • Randomised placebo-controlled and balloon-angioplasty-controlled trial to assess safety of coronary stenting with use of platelet glycoprotein-IIb/IIIa blockade. Evaluation of platelet IIb/IIIa inhibitor for stenting

    Lancet

    (1998)
  • Platelet glycoprotein IIb/IIIa receptor blockade and low-dose heparin during percutaneous coronary revascularization

    N Engl J Med

    (1997)
  • The EPIC Investigation

    Use of a monoclonal antibody directed against the platelet glycoprotein IIb/IIIa receptor in high-risk coronary angioplasty

    N Engl J Med

    (1994)
  • Enhanced suppression of the Platelet IIb/IIIa receptor with integrilin therapy. Novel dosing regimen of eptifibatide in planned coronary stent implantation (ESPRIT): a randomised, placebo-controlled trial

    Lancet

    (2000)
  • A.M. Lincoff et al.

    Bivalirudin and provisional glycoprotein IIb/IIIa blockade compared with heparin and planned glycoprotein IIb/IIIa blockade during percutaneous coronary intervention: REPLACE-2 randomized trial

    JAMA

    (2003)
  • T. Scholz et al.

    The GPIIb/IIIa antagonist eptifibatide markedly potentiates platelet–leukocyte interaction and tissue factor expression following platelet activation in whole blood in vitro

    Platelets

    (2002)
  • S.S. Kabbani et al.

    Platelet reactivity in coronary ostial blood: a reflection of the thrombotic state accompanying plaque rupture and of the adequacy of anti-thrombotic therapy

    J Thromb Thrombolysis

    (2001)
  • S.S. Kabbani et al.

    Platelet reactivity characterized prospectively: a determinant of outcome 90 days after percutaneous coronary intervention

    Circulation

    (2001)
  • M.R. Barnard et al.

    Whole blood analysis of leukocyte–platelet aggregates

    Cur Protoc Cytometry

    (2003)
  • F.D. Rubens et al.

    The effect of antithrombin III-independent thrombin inhibitors and heparin on fibrin accretion onto fibrin-coated polyethylene

    Thromb Haemost

    (1993)
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