Aggarwal Atul, Sobel Burton E, Schneider David J
Department of Medicine, The University of Vermont College of Medicine, Burlington, VT, USA.
J Thromb Thrombolysis. 2002 Jun;13(3):161-5. doi: 10.1023/a:1020478923794.
Platelet reactivity predicts complications after percutaneous coronary intervention (PCI). Accordingly, agents that suppress platelet reactivity should decrease adverse events after PCI. This study was designed to determine the effects of therapeutic concentrations of unfractionated heparin (UFH), bivalirudin, or enoxaparin alone or in combination with tirofiban on platelet reactivity.
Blood taken from 13 patients with coronary artery disease was exposed to each anticoagulant alone or in combination with tirofiban ex vivo. Platelet reactivity was characterized with flow cytometry to quantify the percentage of platelets capable of binding fibrinogen (activation of glycoprotein IIb-IIIa) and expressing P-selectin in response to adenosine diphosphate (ADP, 0, 0.2, and 1 microM).
Platelet reactivity was greater in blood treated with UFH than in blood anticoagulated with bivalirudin with respect to both the capacity to bind fibrinogen (by 4 +/- 1.8%, p = 0.01) and P-selectin expression (by 7.7 +/- 0.7%, p, < 0.0001) in response to 1 microM ADP. Platelet reactivity was greater in blood treated with UFH than in blood exposed to enoxaparin with respect to P-selectin expression (by 7 +/- 1.1%, p, < 0.0001) in response to 1 microM ADP. Platelet reactivity was similar in blood treated with bivalirudin or enoxaparin. Addition of tirofiban suppressed the capacity to bind fibrinogen in the presence of each anticoagulant to a similar extent.
As platelet reactivity is greater in blood anticoagulated with UFH in comparison with blood anticoagulated with enoxaparin or bivalirudin, the use of bivalirudin or enoxaparin rather than UFH during PCI should contribute to a reduced incidence of adverse cardiac events after PCI.
血小板反应性可预测经皮冠状动脉介入治疗（PCI）后的并发症。因此，抑制血小板反应性的药物应能减少PCI后的不良事件。本研究旨在确定治疗浓度的普通肝素（UFH）、比伐卢定或依诺肝素单独使用或与替罗非班联合使用对血小板反应性的影响。
从13例冠心病患者采集的血液在体外分别单独暴露于每种抗凝剂或与替罗非班联合。用流式细胞术对血小板反应性进行表征，以量化能够结合纤维蛋白原（糖蛋白IIb-IIIa激活）和响应二磷酸腺苷（ADP，0、0.2和1微摩尔）表达P-选择素的血小板百分比。
在响应1微摩尔ADP时，就结合纤维蛋白原的能力而言（增加4±1.8%，p = 0.01）以及P-选择素表达而言（增加7.7±0.7%，p < 0.0001），用UFH处理的血液中的血小板反应性高于用比伐卢定抗凝的血液。在响应1微摩尔ADP时，就P-选择素表达而言（增加7±1.1%，p < 0.0001），用UFH处理的血液中的血小板反应性高于暴露于依诺肝素的血液。用比伐卢定或依诺肝素处理的血液中的血小板反应性相似。添加替罗非班在每种抗凝剂存在下对结合纤维蛋白原能力的抑制程度相似。
由于与用依诺肝素或比伐卢定抗凝的血液相比，用UFH抗凝的血液中的血小板反应性更高，因此在PCI期间使用比伐卢定或依诺肝素而非UFH应有助于降低PCI后不良心脏事件的发生率。
