International Circulation: Thank you Dr. Gary Mintz and Dr. Yun Dai Chen for joining us at ACC 2009. First thing I’d like to ask is that contrast imaging was a novel, yet clinical available technique that has the potential to enhance IVUS based characterization of atherosclerotic plaques. Do you think that contrast enhanced IVUS is feasible in the clinic, Professor Mintz?
《国际循环》:非常感谢Gary Mintz 教授和陈韵岱教授参加2009年ACC年会。我的问题是:对比成像是一种新型、临床可行的技术,可用于增强IVUS下动脉粥样硬化斑块特点。您认为对比增强IVUS在临床是否可行?
Prof. Gary Mintz: Well first let me give you the background, one of the things that are seen in vulnerable plaques is an increase amount of the neo-vascularization somewhat related to inflammation. It is feasible to do contrast enhanced IVUS by doing background subtraction before and after injection of standard contrast media such as iohexol and that the density of the contrast once you have done background subtraction as well as the timed activity curve has been shown to correlate with the increased neo-vascularization. So that is the background. Whether it is clinically feasible is another issue. There are many different ways to detect vulnerable plaques and this is just one of them. Is it better than others? I’m not sure, but unfortunately, there have been very little clinical advances in the last year or two while there have been significant advances in other technologies. So the science may make sense but the practical application of it may or may not make sense. Plus there is a whole other issue takes maybe thirsty seconds, maybe longer and you have to find the point at which you want to acquire the images. So it is not just a simple pullback, you have to identify a position, you have to leave the transducer in place, you have to do background image acquisition, you have to do contrast injection, you have to do background subtraction, you have to do your timed activity curves, and hopefully you are at the right point. Gary Mintz教授:首先让我说一下背景,我们发现在易损伤斑块内新生血管化与炎症相关。对比增强IVUS是可行的,在标准对比造影剂(如碘海醇)注射前后行背景减影,行背景减影后的造影密度及定时活动曲线与新生血管化活动增加相关。这就该技术的背景。是否临床可行是另外一回事。目前有很多其他方法检测易损伤斑块,这只是其中一种。是否就优于其他方法?我不确信,遗憾的是,在过去一两年内临床进展似乎很小,而其他技术却突飞猛进。所以这项技术可能说得通,但是实际应用不一定可行。另外还有就是可能花半分钟或更长的时间找到你想成像的位点。然后不是简单地把机器放回去就可以了,你还必须要定位、将探头固定、做背景影像获取、注射造影剂、背景减影、做定时活动曲线等等,所有这一切还必须要建立在你选对了位置做才行。
International Circulation: So this makes it quite difficult?
《国际循环》:所以操作起来很难?
Prof. Mintz: At this point to me it seems relatively cumbersome. But that does not mean that it isn’t a potential area which someone can figure out a way to improve the technology and make it clinically viable, just the way it stands today is quite cumbersome.
Mintz教授:这点对我来说确实相对繁琐。但并不意味着没有潜力,或许有人可以想出更好的办法改进这项技术使其均有临床可操作性,只不过现在这项技术还太显复杂。
International Circulation: Professor Chen, what about in the case of vulnerable plaques detection? Can you add some of your views perhaps on your views on the situation in China, any new research or things that you can add?
《国际循环》:陈韵岱教授 ,据您了解易损伤斑块检测进展如何?您能谈些您对中国目前情况的看法吗?是否有新的研究进展呢?
Prof. Chen: Yes, also it is quite a hot topic in China and also before today, I communicated a lot with Professor Gary Mintz. I think contrast enhanced intravascular imaging is quite a new technique. I would like to know, what is this technology is based on? Is it compared with the non contrast enhanced intravascular imaging or compared to the other currently available technology to detect the vulnerable plaque?
陈韵岱教授 :在中国这也是个热点话题,而且此前我还与Gary Mintz教授沟通了很多,我认为对比增强血管内成像的确是个新技术。我非常想知道这项技术是基于什么?它比较倾向非对比增强血管内成像,还是其他目前可行的探测易损伤斑块的技术呢?
Prof. Mintz: It has been primarily compared to non contrast enhanced imaging. It is based on work that doesn’t seem to make sense but it has been to my knowledge no studies for example pairing this with OCT or spectroscopy or any other technique. This is just been a proposed mechanism and the case examples shown have been quite impressive. But that does not mean that it translates to a clinical technique for detecting vulnerable plaque.
Mintz教授:一开始是基于非造影增强成像。它基于一项似乎不太行得通的技术,但据我所知没有研究将其与OCT、光谱学或任何其他技术联系在一起。这只是一种刚被提出来的理论机制,病例举例也给人印象深刻。但这并不意味着就可以应用于临床监测易损伤斑块。
Prof. Chen: In China the optical coherence tomography is already approved by the SFDA but only usable for detecting vulnerable plaque. For some acute coronary artery patients, if angiograph results show that there is quite a lot of irregularly shaped plaque and thrombus while the stenosis rate is not very high but already with cardiac events, then generally you use OCT technology to detect whether or not we can find some rupture of the capillary or other with some thrombus. Other things are also used, non invasive technology like a CT or MRI.
陈韵岱教授 :在中国,光学相干层析技术已经获得SFDA批准,但仅限用于检测易损伤斑块。对某些急性冠脉患者,如果造影结果提示有很多不规则斑块和血栓,但狭窄率并不是很高,但已经出现心脏事件,通常应用OCT技术检测是否可以发现毛细血管破裂或存在血栓。当然,也应用了其他技术,如非侵入性技术:CT或MRI。
International Circulation: What about in the case of intravascular MRI to evaluate coronary plaque. Professor Mintz, what do you think of the technique, does it have potential and can it be useful at all?
《国际循环》:应用血管内MRI评价冠状动脉斑块如何?Mintz教授,您怎样看待这项技术,是否有应用前景,是否有用?
Prof. Mintz: Well there has been couple of projects to develop an intravascular MRI device because MR is very good at detecting lipids and the vulnerable plaques are very lipid rich. The problem is making a clinically viable catheter technique. The last catheter design that I saw which was not taking into clinical use, allowed for a couple of samples along the coronary artery at one time. But the one at which there is actual clinical experience only imaged about 120 degrees of the coronary artery at one time and requires you to use a offset balloon and push the catheter against the vessel wall, and stop flow during acquisition, let the balloon down, rotate it 1/3 of the circumference, repeat the process and do it again. That only gave you a window of about 10mm in length. So I actually think that is while it sounded like a good idea, it is one of those ideas that are starting to, or maybe it already has, disappeared. Also it is extremely expensive. If your goal is to detect lipid within the vessel wall, infrared spectroscopy is clearly a more user friendly technique and certainly compared to intravascular MR. The pilot study that was done on intravascular MR looked at a number of patients, about a hundred patients, an