International Circulation:  What are your thoughts about the predicators of stent thrombosis following primary PCI for stemi?
国际循环：急性ST段抬高性心梗患者PCI治疗后如何预防支架内血栓形成？

Prof. Bruce Brodie:  I think by far the most important is compliance to dual anti-platelet therapy， aspirin and chlopidogrel， currently.  There are a lot of patients who come to the CATH lab with acute stemi and we don’t know if they are going to be compliant or not.  It makes it a difficult decision to put in a bare metal stent or a drug-eluting stent.  Bare metal stents do not require the long duration of chlopidogrel and aspirin that drug-eluting stents do.  Patients who are non-compliant and stop there medication of plavix or aspirin and chlopidogrel early are at the highest risk of stent thrombosis.  Beyond that we look at other associated factors such as renal insufficiency， which is associated with higher risk， and also diabetes， smoking， and smaller vessels.  There is one thing we can do something about and that is underdeployment of stents at the time of stent implantation.  This is a strong predictor of late stent thrombosis and makes it very important that we get full expansion on these stents.  In the setting of stemi that is very difficult because these vessels are frequently in spasm and there is thrombus so it is easy to under-size the stent.  You often have to give a lot of nitroglycerin to give the vessel a chance to grow and have a chance to get a fully expanded stent in stemi patients. 
Prof. Bruce Brodie: 我认为目前最重要的遵守双重抗血小板治疗原则，使用阿司匹林和氯吡格雷。有很多急性ST段抬高性心梗患者到了心导管室，我们不知道他们的依从性如何，这就很难决定到底是植入金属裸支架还是药物洗脱支架。金属裸支架不需要长时间使用氯吡格雷和阿司匹林抗血小板治疗，而药物洗脱支架需要。依从性差、过早停用氯吡格雷或阿司匹林的患者支架内血栓发生率高。除此之外，其他相关因素包括肾功能不全、糖尿病、吸烟、血管较细等也是支架内血栓形成的高危因素。有一项与人为操作相关的危险因素是支架植入时释放不良。这是晚期支架内血栓形成的重要因素，因此我们应该让支架充分扩张释放。在急性ST段抬高性心肌梗死时，由于此时血管通常处于痉挛状态，而且血管内还有血栓，因此很容易低估支架的大小。通常需要给予硝酸甘油，让血管有机会扩张，以便使支架充分扩张释放。