<International Circulation>: Animal studies and clinical trial findings are often completely different; what is your opinion of this phenomenon? How can we raise the value of animal studies?

Dr. Granada: One must start by identifying the objectives or purpose of the research that you are doing at a very early stage. One of the first things that you need to show is feasibility. For example， you should show feasibility of implanting a device， doing imaging into a vessel， of a device， or of a concept. The next step should be focused on safety. What do I mean by safety? If you are going to introduce a device into an artery that you are not going to rupture the artery and making sure that when you implant a device that you do not have major complications. At that time you are making sure that the technology that you are using is safe. When you go to the next level you are looking at efficacy. This is where you start seeing differences. Most of the differences that we see in animals are in the efficacy endpoints because we use normal animals. We use young animals with no disease burden and this is comparable to if you used teenagers for cardiovascular research. As a result， the field is now moving in the direction of using more complex animal models that actually simulate a human environment. For instance， we have an atherosclerotic pig that develops atherosclerosis in a natural way and by implanting devices such as stents in this animal model we have seen similar outcomes to what you would expect in a human. Therefore， as we move into diseased animal models we are going to be able to narrow the differences that we see with normal animals.