International Circulation: Effective restoration of myocardial perfusion by PCI in STEMI is a life-saving therapy. Please talk about the advantage and disadvantage in using unfractionated heparin， low molecular weight heparins， the factor Xa inhibitor fondaparinux， and the direct thrombin (factor IIa) inhibitor bivalirudin in PCI procedure.
　　国际循环：STEMI患者采用PCI疗法进行心肌灌注的有效恢复是一种能够挽救生命的疗法。请您谈一谈在PCI的治疗过程中，采用普通肝素，低分子肝素，Xa因子抑制剂磺达肝素，以及直接凝血酶（因子IIA）抑制剂比伐卢定这四种药物各自的优势和劣势？
　　Prof. Stone: We use bivalirudin in almost 100% of cases because it prolongs survival. It is an important endpoint for patients. When we think about using anticoagulants in patients with primary PCI undergoing primary angioplasty， the major consideration is to allow us to safely produce the procedure to minimize any chance of distal embolization， to improve epicardial and microcirculatory flow and to prevent stent thrombosis. There are four possible agents that people have investigated: unfractionated heparin， low molecular weight heparins， the factor Xa inhibitor fondaparinux， and the direct thrombin (factor IIa) inhibitor bivalirudin. Low molecular weight and unfractionatedheparin usually have to be used with glycoprotein inhibitor and that’s because those anti-thrombin inhibitors activate platelets which can actually paradoxically increase ischemia. When you add a glycoprotein IIb/IIIa inhibitors which blocks the final common pathway of platelet aggregation it will markedly reduce ischemia but it causes more bleeding and thrombocytopenia. When those agents have been compared to bivalirudin alone in patients with acute coronary syndrome， that is non-STEMI and STEMI， bivalirudin has been shown to have comparable suppression of ischemic complications while markedly reducing bleeding and thrombocytopenia and as a result has led to better survival.
　　Fondaparinux is a very good agent to use in patients with mild unstable angina or those who need prolonged prophylaxis of the coagulation system. It’s given subcutaneously but in and of itself it does not inhibit contact thrombosis. When it was used in patients with STEMI and those with acute coronary syndrome as the sole anticoagulant you would get thrombis attached to the catheter which would then go downstream into the coronary artery. So it is no longer permitted， recommended or allowed as the sole anticoagulant in patients with ACS. For those patients with acute coronary syndromes undergoing invasive strategy，bivalirudin is now the preferred agent followed by either unfractionated low molecular weight heparin with a glycoprotein IIb/IIIa inhibitor.
　　Stone教授：我们在所有病例中几乎都百分之百的使用比伐卢定治疗，因为其能够延长存活时间，这对于患者来说是一个重要的观察终点。当我们考虑对接受血管成形术的PCI患者采用抗凝血剂治疗的时候，主要考虑的是手术过程安全，尽量降低远端栓塞的几率，改善心外膜和微循环血流以防止支架内血栓的形成。人们已经研究过的合理用药有四种，普通肝素，低分子肝素，Xa因子抑制剂磺达肝素和直接凝血酶（因子IIA）抑制剂比伐卢定。低分子肝素和普通肝素通常需要与糖蛋白抑制剂合用，这是因为这些抗凝血酶抑制剂能够激活血小板，实际上能够反常增加局部缺血的风险。加用糖蛋白IIb/IIIa抑制剂能够阻碍血小板聚集的最终共同通道，显著的降低局部缺血的风险但是会导致更多的出血和血小板减少事件。当这些药物与比伐卢定在急性冠脉综合征患者（即，非STEMI和STEMI患者）上进行对比时，比伐卢定能够在等效降低缺血并发症的同时，显著的降低出血和血小板减少的发生率，因此能够获得更好的存活率。
　　磺达肝素是一种非常好的药物，适用于轻度的不稳定型心绞痛患者，或者那些需要延长凝血机制的预防时间的患者。这种药物为皮下给药，但是就其本身而言不会阻碍血栓形成。当在STEMI患者和急性冠脉综合征患者中作为唯一抗凝血剂使用时，会让支架上粘附的血栓进入导管，进而顺流而下进入冠状动脉。因此不再采用这种疗法，而是建议或者允许其作为唯一的抗凝剂在ACS患者中使用。对于那些采用非侵入性疗法的急性冠脉综合征患者，比伐卢定是目前除普通肝素，低分子肝素和糖蛋白IIb/IIIa抑制剂的首选药物。