<International Circulation>: Optical Coherence Tomography (OCT) is a helpful tool for lesion assessment. Would you please to assess the value of quantitative OCT in percutaneous coronary intervention (PCI)?

Prof. M.C. Morice: OCT is a new tool and very helpful in assessing the lesion and the result of stenting. OCT is much more precise than Intravascular Ultrasound (IVUS). Maybe it could be a way to know if it is the correct time to stop anti-platelet treatment just because the stent is nicely analyzed. I can not imagine a new stent coming on the market without OCT data early after implantation and during follow-up.

Prof. Wen Shangyu: OCT has some drawbacks because the procedure is very difficult. You have to occlude the artery. So it may be very good for research， but in clinical work， IVUS is more useful than OCT. Moreover， OCT is very expensive in China; I think there are only two OCT machines in China. The availability of the equipment is a big limitation for OCT in China.

Prof. M.C. Morice: I agree with you that OCT requires occlusion， cleaning of the artery， which is really not easy. Also， you can not see the wall surface very well in very big arteries. IVUS is easier to apply to more patients， but OCT is more precise.
<International Circulation>: During these past few years， non-invasive vascular imaging including multi-slice CT (MSCT)， MRI is the hot topic. Do you think MSCT alone is best suited for ruling out coronary artery disease?

Prof. M.C. Morice: With the excellent images， MSCT can be a useful tool to detect coronary artery disease. However， it has its own limitation in particular at this moment. First， MSCT can not provide ischemic information but anatomy. Second， the radiation dose of MSCT is at least three times of coronary angiogram. At the moment all the companies are working on lowering the dose and I think that will increase the indication of MSCT.

Prof. Wen Shangyu: MSCT may sometimes be useful for total occlusion. Sometimes it can help us know where the calcification is and know what the duration of the occlusion is. But actually the dose is very high in CT which may be a problem. However， now a new MRI-CT， dual-source CT may be helpful.

<International Circulation>: We know that you were involved in the SYNTAX trial. Could you introduce a little bit about the design and main results of this trial? And what is the message that we obtain from the SYNTAX trial?

Prof. M.C. Morice: SYNTAX is really a very important trial because since the last decade both PCI and surgery have made major progress. It was time to reconsider of the two approaches in a randomized fashion. What is also very interesting in the design of the SYNTAX trial is the all-comer strategy， which means that each patient that came into the center， with triple-vessel disease or left main stem disease was randomized. Each patient was assessed by both cardiac surgeons and interventional cardiologists; if the patient can be treated by both CABG and PCI， the patient is accepted for randomization; if either CABG or PCI is deemed unsuitable for technical reasons or the presence of co-morbidities， then the patient is recruited into one of two parallel registries for CABG or PCI. Most of the previous trials include no more than 4% of the population. So， it was difficult to generalize the result to the whole population because it was highly selective.

Prof. Wen Shangyu: In the subgroup of patients with the left main stem disease， SYNTAX result is favorable for PCI. Early in this year， Dr. Park also gave a report with a favorable result for PCI. Do you think the two results can change the practical strategy for patients with the left main stem disease?

Prof. M.C. Morice: The results are sufficiently encouraging. The SYNTAX trial did not meet its end point that PCI was inferiority due to re-intervention in the PCI group. In terms of safety there is no doubt a real equivalency of death， MI， stroke in the two groups. In particular， when left main stem disease is isolated or plus one-vessel disease， this trial really achieved an excellent result. I think left main will not be a taboo with the progress of PCI.
Prof. Wen Shangyu: Another thing we have learned from SYNTAX trial is SYNTAX score. Can you give some introduction to the SYNTAX score? 

Prof. M.C. Morice: I think this will be important information coming from that trial. SYNTAX score provides guidance to physicians on optimal treatment options for patients. The score is high when there is a left main lesion， bifurcation， total occlusion， and so on. SYNTAX score can help to predict the outcome of patients， that higher score means more major adverse cardiac events (MACE).

《国际循环》：请您谈谈光学相干断层成像（OCT）在经皮冠状动脉介入术（PCI）中的应用价值。

Morice教授：OCT是一个新的诊断工具，对于评估病变和评价支架的效果非常有帮助。它的精确性高于IVUS。因为它可以对支架进行很好的分析，因此也许可以用于判断停止抗血小板治疗的准确时间。一个新的支架产品上市必然要有置入后以及随访期间的OCT数据作为保证。

温尚煜教授：OCT有它的不足——操作时必须阻断血流，所以它可能对研究很有帮助，但在临床工作中IVUS 比OCT更有用。此外，OCT非常昂贵，据我所知，中国只有2台OCT 仪器，这也限制了它的应用。

Morice教授：的确，OCT的操作存在一定的困难，而且OCT很难看清楚大动脉的管壁。IVUS的适用性更好，但OCT更精确。

《国际循环》：单独使用MSCT是排除冠状动脉疾病的最佳选择吗？

Morice教授：MSCT成像质量很好，可以作为检测冠心病的有效工具。然而，它仍有局限性：首先，MSCT只能提供解剖信息，而不能提供缺血信息；其次，它的辐射剂量至少是冠状动脉造影的3倍。目前各家公司正致力于降低辐射，我认为这将扩大MSCT的应用。

温尚煜教授：MSCT对诊断完全闭塞病变会有帮助，可以帮我们了解钙化病变的定位以及阻塞病变的持续时间。但是CT的辐射剂量大仍是我们面临的一个问题。新型MRI-CT——双源CT可能有助于解决这一问题。

《国际循环》：请您简单介绍一下SYNTAX试验的设计和主要结果。

Morice教授：SYNTAX试验是一项非常重要的研究。近10年，PCI和手术技术都取得了很大进步，现在应该对这2种治疗方法进行重新评价。SYNTAX试验设计方面有趣的是，它是一项all-comer试验，就是说每位来中心的三支血管病变或左主干病变的患者均进入随机化。同时由介入心脏病专家和外科医生对患者进行评估，如果患者既可以进行CABG也可以进行PCI治疗，那么患者被随机分组。如果由于存在技术或共存病等情况导致患者不适宜进行某一项治疗，那么他将进入另一项平行注册研究。之前的绝大部分研究入组的患者不超过4%，由于这种高度选择性限制了试验结果的适用范围。

温尚煜教授：SYNTAX 试验的一个亚组分析表明，左主干病变更适宜PCI治疗。今年Park教授也在一项报告中提出了有利于PCI的结果。您认为这会改变对左主干病变的治疗策略吗？

Morice教授：SYNTAX研究中，并未由于PCI组需要更多的介入，而得到PCI不如CABG的结果。从安全性的角度看，PCI组和CABG组死亡、心肌梗死和脑卒中事件上没有差异。尤其，对于单纯的左主干病变或左主干+单支血管病变，这项研究得到了很好的结果。随着PCI技术的进步，左主干病变将不再是PCI的禁忌证。

温尚煜教授：请您介绍一下SYNTAX评分的应用价值。

Morice教授： SYNTAX评分可以指导内科医生为患者选择最佳的治疗措施。当存在左主干病变、分支病变、完全堵塞病变等情况时，评分升高。SYNTAX评分可以协助判断患者的预后，评分越高，主要不良心脏事件（MACE）的发生率越高。

专家介绍：

Prof.Morice MC：
ESC大会特邀发言专家，法国Jacq