<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.
<International Circulation>: Sometimes the same clinical trial can have different conclusions， including meta-analysis. What is your opinion of this situation? How can we get the most useful information from the literature?
Dr. Granada: This is why you must pay attention to the type of study you are examining. There are randomized clinical studies and what we call real life experiences， which are the registries. In terms of meta-analysis， you must be careful because the conclusion lies in the eye of the beholder and how you want to analyze the data.
<International Circulation>: A lot of experimental research has received financial support from large corporations. How can we handle the relationship between trial findings and commercial sponsorship? How can we ensure the trials are scientific and precise?
Dr. Granada: This is a very important question. One of things that we do to ensure this is following good laboratory practices. The final endpoint in the studies that we do is always histology in which the final analysis is done by independent laboratories and the data analysis is done in an independent manner. Most of the studies that are done at the experimental stage are aiming to finding non-competitive differences. For clinical research it is rare that we do head-to-head comparisons or superiority studies. What we do is technology validation to ensure that any given technology is safe and shows signs of efficacy. We never do head-to-head comparisons in which there is an incentive to show superiority. Our objective is to show biological efficacy and safety for any given device or technology. Therefore， the incentive is only to show that a device is efficacious and safe， but not superior to anything else.
<International Circulation>: Implanted stem cells are a promising treatment in cardiology. What is your view of this technology?
Dr. Granada: Stem cells have gone through what I call a biphasic response. There was a lot of excitement and a good amount of investment went into that area from the NIH and also from industry and other sources. As we started to understand the complexity of the field， including the need for sophisticated mapping systems， imaging systems， catheter systems， and most importantly and efficacious cell， the field has gone more into a research mode than a product development mode. However， the field is moving very rapidly and the imaging companies have made important advances in algorithms for mapping and detecting， catheters are getting safer， and biologists are learning more about cell implantation. As a result， I am excited about what is to come and within the next several years we are going to see significant advances in endomyocardial cell delivery.
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