International Circulation：Bioabsorbable stents can be called as the new milestone in the history of PCI， but it is at the beginning of development. How large is the gap between BRS data and it’s theory building in your opinion?

　　《国际循环》：生物可吸收支架堪称介入史上的第四个里程碑，但仍处于起步阶段。目前已有少数支架在临床使用，您认为当前生物可吸收支架数据与理论构建还有多少差距？

　　Dr. Stone : Thank you. So the bioresorbable scaffolds are a very exciting development and they offer the potential to overcome many of the limitations of metallic drug eluting stents by absorbing， going away without the first 2 to 3 years， they can restore the normal vessel physiology， allow adaptive remodeling responses， allow plaque regression， and other advantages but of course we have to translate this into clinical advantages within clinical studies before they start being used widely or replace metallic drug eluting stents. We are just starting to get robust clinical data to see if these devices are as good or better than metallic drug eluting stents and the first study we have was the ABSORB II randomized trial which was 501 patients with relatively simple lesions. They were randomized to either the Absorb bioresorbable scaffold， that is the one that is made by Abbott， or a standard metallic everolimus eluting stent and with follow up to 1 year the outcomes were pretty similar in terms of the hard clinical events between Absorb and Xience although the study was not really yet powered to show differences. There were some advantages to Absorb in terms of less ischemia at 6 months on exercising testing and less angina recurrence within the first year and there is a hypothesis that there will be less angina with Absorb bioresorbable scaffold compared to a metallic drug eluting stent. With this in mind， we are performing 2 very large studies – ABSORB III and ABSORB IV which together are in randomizing 5000 patients with simple and moderately complex lesions， both stable coronary artery disease， unstable angina， and non ST segment elevation MI to see if Absorb compared to Xience really does reduce angina and improve long term freedom from adverse ischemic events though it is going to take several years for us to really know the answer but we are now on a good pathway to having this evidence.

　　Stone 教授：谢谢。生物可吸收支架是心血管介入领域非常令人振奋的一个发展与进步，其具有可吸收性，2~3年后可消失，因此，可能具有重新恢复血管生理、导致适应性重构反应、促进斑块消退等优势，具有能够克服很多金属药物洗脱支架局限性的潜力。当然，在开始广泛应用生物可吸收支架或是用其替代金属药物洗脱支架前，我们需要开展相关临床研究证实生物可吸收支架确实具有上述临床优势。我们已经开始获得了有关生物可吸收支架是否与金属药物洗脱支架相当或更好的强力临床证据。这方面的首项研究ABSORBⅡ随机试验入选501例存在相对简单病变的患者，将其随机分为Absorb生物可吸收支架（简称Absorb支架，雅培研制）组与标准金属依维莫司药物洗脱支架（Xience支架）组。随访1年结果显示，尽管未能发现Absorb支架组与Xience支架组的临床硬终点事件发生率有显著差异，但起码发现两组患者的上述事件发生率非常相似。此外，与Xience支架相比，Absorb支架可减少术后6个月时运动试验期间的缺血事件，减少术后1年内心绞痛的发生。这提示，与金属药物洗脱支架相比，可能应用Absorb生物可吸收支架后会更少发生心绞痛。为验证这一点，我们正在开展ABSORB Ⅲ及ABSORB Ⅳ两项大型研究，共计随机入选5000例简单及中等复杂程度的稳定性冠心病、不稳定性心绞痛及非ST段抬高心肌梗死患者以确定“与Xience支架相比，Absorb支架能否减少心绞痛的发生，改善长期无不良缺血事件发生率”。虽然我们可能需要花费数年的时间才能真正知道答案，但至少现在我们有了获取相关证据的好方法。

　　International Circulation：Along with the development of PCI， unprotected LM bifurcation lesion never be the absolute contraindication， which is increasingly treated with PCI recently. And SYNTAX trial provide more choices to lower risk patients， and the results of EXCEL trial provide evidences again. What are the problems to be solved in the years to come?

　　《国际循环》：随着导管介入技术的快速发展和技术的不断进步，无保护左主干病变的经皮冠脉介入（PCI）治疗已不再是绝对禁忌，并且逐渐增多。特别是SYNTAX的研究结果让低危患者有了更多治疗选择，EXCEL研究也再次给出了坚实的证据。纵观左主干病变治疗的多年发展，您认为临床实践还存在哪些疑惑尚未解决？

　　Dr. Stone : Right so the SYNTAX trial was a large trial with a first generation drug eluting stent， the TAXUS drug eluting stent， versus bypass surgery in patients with either unprotected left main or triple vessel disease and it was actually a negative trial. The results with bypass were better but if you looked in the subset of patients with left main disease and particularly the subset of patients with relatively non complex unprotected left main disease， there it looked like TAXUS did as good or maybe a little bit better than bypass surgery. So this hypothesis， that cannot be a definitive finding， but the hypothesis that led to the EXCEL trial which is a large randomized trial in approximately 2000 patients of bypass surgery versus better drug eluting stents， that is the fluoropolymer coated everolimus eluting stent called Xience. Here we are only enrolling patients with unprotected left main disease with a SYNTAX score up to 32 so they are simple or moderately complex concomitant coronary disease other than the left main. We have randomized all those patients and they are in their follow up stage right now and we expect to have that result by PCT in the fall of 2016. If that looks good for Xienceeverolimus eluting stents， then that might become the new standard of care for unprotected left main disease.

　　Stone教授：SYNTXA试验是有关第一代药物洗脱支架即TAXUS药物洗脱支架与冠状动脉旁路移植在无保护左主干病变或三支血管疾病患者中应用的对比研究。其结果为阴性，总体来说，冠状动脉旁路移植要优于TAXU药物洗脱支架；但对左主干病变患者尤其是相对并不复杂的无保护左主干病变患者而言，TAXU药物洗脱支架与冠状动脉旁路移植相当，甚至可能会稍优于后者。因此，该研究未能得出有关TAXU药物洗脱支架与冠状动脉旁路移植对比的明确结论，为此人们又设计开展了EXCEL试验。EXCEL试验是一项大型随机试验，入选近2000例SYNTAX评分高达32分的合并简单或中等复杂程度冠心病的无保护左主干病变患者，随机分为冠状动脉旁路移植组与相对TAXU药物洗脱支架而言更好的药物洗脱支架（即氟聚合物涂层依维莫司药物洗脱支架Xience支架）组。目前，研究已进入到随访阶段，预计结果将于2016年秋天发布。如果研究结果能够证实对上述患者而言，应用Xience依维莫司洗脱支架的效果更好，则有望为无保护左主干病变的治疗提供新标准。