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Interactive Learning : HealthCast Transcripts

Episode 16 : The Critical Role of Research

Release Date: April 30, 2007

Dr. David Meyerson: Hi, I'm Dr. David Meyerson, cardiologist at Johns Hopkins and your host for this edition of Vascular Disease Foundation's HealthCast. Again, we are so very excited to bring you excellent, easy to understand science on all topics relating to heart and blood vessel diseases as a public service. As a public education forum, the Vascular Disease Foundation is made up of representatives of premiere medical and scientific advisory groups throughout the country that relate to vascular diseases. These are groups that use peer-reviewed science to verify that the information you are getting is nationally recognized as the very best and most reliable data available.

We're talking about peripheral arterial disease, narrowings or blockages in the arteries that nourish the legs which can limit your ability to walk, cause pain, cause ulcers of the legs and in extreme situations, can even cause one to risk amputations. These are largely preventable diseases. Once developed, they are very treatable diseases and the early recognition and treatment can prevent your disability, promote your physical well-being and help you maintain the healthiest and most active lifestyle you possibly can. We used that analogy of the sixty- year-old house. If the plumber told you that the pipes in the basement were corroded, it wouldn't, it shouldn't surprise you that the pipes on the second floor were also at risk In our last episode, we mentioned very special information which tells us that identifying certain conditions of the circulation of the legs may be a critical window on the potential disease lurking in other parts of the body. We continue with Dr. Alan Hirsch. He's the Director of the Vascular Medicine Program of the Minneapolis Heart Institute. Like me again, he's a card-carrying cardiologist, but he's also Professor of Epidemiology and Community Health, University of Minnesota School of Public Health, he's a past president of the Vascular Disease Foundation and he is an author on several of the papers that appear in recent medical journals talking about peripheral arterial disease and the risk it poses to all of us. Alan, Dr. Alan Hirsch, thank you again for being with us.

Dr. Alan Hirsch: Really it's a pleasure being here. I have also become a fan of the PodCasts.

Dr. David Meyerson: Oh wonderful. It's a wonderful way to reach people at their convenience. They can turn on the PodCast at their home computer; they can download it to a portable device and listen to it wherever they want. They could even pull it up at their office during their lunch break. It's just a very convenient way and again, the Vascular Disease Foundation and people like you are to be thanked for giving the public such superior, truly superior, truly first rate information. Now, let's go back, there was something -- our listeners need to listen because we're going to tell them during this PodCast about how they can identify certain risks of heart attack and stroke and mortality just by paying attention to other areas of the body, but before I want to do this, I want to touch upon an area that's very near and dear to your heart, no pun intended. And that's the following: when we do clinical trials in this country, we are trying to ask questions when a research committee gets together at a major university, they are not doing this just to make people guinea pigs. First of all, we have something called informed consent. Nobody in this country gets in a research study or gets research done on them unless it is in the clearest possible way, you are told this is a trial, these are the risks, these are the benefits. However, I want to go a step further. When we do clinical research, we do it because we truly don't know whether one therapy is better than the other. So, Alan, tell us what happens there? We try to pit what we think perhaps the one or two best therapies are against one or two of the most promising new things. Is that right?

Dr. Alan Hirsch: Right. I think that the constant that we're talking about is the need for the public to realize that when they go to their physician to ask for their advice regarding a diagnosis or regarding a therapy, the information, the answer comes from research. Comes from other individuals, partnered with their physicians were willing to actually ask the question, what happens when we compare one treatment to the other? And they dedicate themselves to collecting information that's useful for many, many other people including their own family.

Dr. David Meyerson: And so participation in research should really be encouraged?

Dr. Alan Hirsch: Absolutely. You know, just conceptually for me, clinical research, the willingness to help create the knowledge that keeps society healthy is the equivalent of living in a world where the roads are safe, where there's a weather system that allows you to know when a storm is coming, that allows you to build a levee around a city that may be at risk. Without knowledge that we can only create by participating, we don't have the access to information that allows us to navigate our lives.

Dr. David Meyerson: And the patients that are agreeing and the family members that are agreeing to participate in research with quality researches from our major universities, these people are actually giving a gift to society, aren't they?

Dr. Alan Hirsch: Well, it's a gift to themselves and society and let's be as open and community focused as we can be. Everyone participates ideally in a world that creates knowledge so whether at a university researcher and a academically focused private practice, working with both the U.S. government, with the pharmaceutical and device industry, there is no member of society that actually doesn't have a stake in improving the healthcare knowledge environment, so yes, one should actually seek an opportunity during one's lifetime to participate.

Dr. David Meyerson: And again, I'd like to point out that research trials don't generally get done unless we really don't know. If we knew what the answer was going to be, we wouldn't fund with a very large amount of money, a research trial, would we?

Dr. Alan Hirsch: I've always said if we give to our children, the state of healthcare knowledge and treatments that we have now, we haven't done our job as parents or members of society, correct. So there's a major reason to participate is because there are fundamental unanswered questions and they're very basic questions that we really need answers to immediately. Unless we start to ask those questions, collect the knowledge and analyze the data then share it widely with everyone, we stagnate and in fact, we lose a knowledge base. Knowledge creation has to continue forever.

Dr. David Meyerson: Why is it harder to recruit people to participate in good research these days? You know, one of the benefits that people get when they do participate is they do get free healthcare, they get looked at much more often and they may get a higher level of healthcare inherent in their participation. But why is it getting tougher to recruit people?

Dr. Alan Hirsch: Let me try to answer that by both being general about research in the medical community, but also focusing on our interest in this called vascular research. First of all, I'm not sure it's necessarily more difficult or there are any more barriers, but the reasons to participate obviously are that in general, one's safety is almost always exceedingly well protected within a research environment. In other words, one is usually more closely monitored for the particular illness, one usually gets more information about the illness itself to make an informed choice and one has an ongoing relationship with allows you to learn throughout the process and in fact, even when there is a placebo or inactive treatment used, the evidence is crystal clear, that even with placebo treatment generally people are superiorly treated then with routine care. But the barriers that exist are many. I think that the reality is we're surrounded by noise in the media. The current environment is one of creating worry. There have been research experiments done in the past primarily that have had challenges and foibles that scare people. There also car accidents that happen if one only watches the news for a car accident, you would think that you can't drive. So instead of creating a climate of optimism, we live in a climate currently of fear. The joy of participating is developing a relationship with a physician, a nurse that actually is a partnership which everyone learns together in a safe environment, so that's a very brief summary. For vascular diseases, in the past there were very few clinical trials, research studies that one could join. There are more of these, but I fear that most members of the public, whether they have lower extremity peripheral arterial disease or carotid artery disease and stroke, or an aneurysm really don't learn about the studies that exist where they could not only receive care, but actually leave a legacy of knowledge for their family members and for the future generation.

Dr. David Meyerson: Well, you have to admit that when new studies do come out, I think the media is pretty friendly with an attempt to get new good quality science out there, are they not?

Dr. Alan Hirsch: With a grin on my face, here in my office in Minneapolis, I don't agree that the media is friendly to clinical research. I think that the choice of interesting studies are often based on small anecdotes and hype that creates short-term interest and does no often highlight the major importance we could talk about some of these here in which fundamental questions require patients to enroll, media might simply say, "It doesn't make a good story."

Dr. David Meyerson: Well, if something of major importance gets by the media and they choose not to do it, aren't we in part to blame?

Dr. Alan Hirsch: I do believe we live in a democracy and so we get the media we watch and we get the newspapers we read, so there's no question that we never look for blame.

Dr. David Meyerson: You said as a past president of the Vascular Disease Foundation and somebody so involved in epidemiology and I as a – who works for the American Heart Association at times and other groups, I think both of us have a responsibility to make sure that the public knows the new and important information that's getting out there.

Dr. Alan Hirsch: Well here we are on a PodCast. This is one of our mechanisms, so obviously we're devoted to this idea of actually bringing all of the information that is accurate to the public, including access to research studies. I hope as we go forward in the years ahead, we will continue this circle back and let the public know what's out there, what's available that they might want to participate in. They might seek.

Dr. David Meyerson: Absolutely and again I don't want to leave this topic without us accepting the responsibility to take at least a little bit more of the responsibility to get out there and to make sure that the public does know that medicine as a profession need to communicate better and better every day.

Dr. Alan Hirsch: Let me raise the flag higher one more time as we climb the mountain of volunteer base knowledge creation. If I had a friend, a sibling, a parent with an illness where they had questions to ask, I wouldn't simply go to the internet, I would actually help that individual look for research studies, investigators in their area where they might again both gain care as well as learn as much as they can about their illness. In other words, we can help each other reach across and gather the information for participation in clinical trials.

Dr. David Meyerson: That's wonderful, Alan. Now I want to ask you since you just mentioned reaching, I'd like you to just remind us -- we talked last time about a study that involved almost sixty eight-thousand patients from forty-four countries, the data was recent, it was gathered from 2003 to 2004 and tell us why that reach registry was so important in telling us the interrelationship between peripheral arterial disease and cardiovascular risk in general.

Dr. Alan Hirsch: I want to provide then a moment of background for the listeners. On these PodCasts, we've talked about the risk of heart attack and stroke that exists in individuals who have blockages in their leg arteries or peripheral arterial disease. And I think thankfully many physicians also have gained some knowledge that when there's an artery blockage in one place as you said at the opening of the program, you actually face a lifetime risk of future artery related health illness problem. That, on the one hand, is knowledge, but let's side again. We do live in an interesting culture. I live here in Minnesota and for those whoever listen to the Prairie Home Companion, we smile and say, "In our state, all physicians are wise, all nurses empathetic and outcomes above average." With humor, we tend to believe that the care we get, the improvement in outcomes continue to get better year by year. Life is just advancing. The Reach study was a very major international effort offered to help us understand whether we really have accomplished our goal. Reach stands for Reduction of Athrothrombosis for Continued Health and reduction means that we hopefully can make life better and have fewer heart attacks and strokes. When people have atherosclerosis or athrothrombosis, blockage in arteries, for continued health because if you present to your physician today with either known coronary artery blockage or prior stroke or leg artery blockage or even risk factors, you do face an ongoing risk. So Reach designed by many of my colleagues around the world and specifically Dr. Gabrielle Steg and Deepak Bot [phonetic] and many others beyond my ability to name them, were able to ask the question in the current environment, right now, in a healthcare systems around the world in which motivated physicians take care of motivated patients and have access to medications and other interventions, what is the yardstick of benefit that we've achieved? Well, as you said, over these recent years, we were able to work very collaboratively with wonderful primary care physicians to recruit ultimately well over sixty-four thousand individuals from nearly every major country in the world and over twenty-four thousand in the United States to ask what is the rate of heart attacks, strokes, other adverse outcomes and death and for those patients who participated, they signed an informed consent form and said, "During my routine care with my physician, I will allow investigators privately with no loss of private information to measure when I'm hospitalized, whether I suffer heart attack and whether I still exist." And by collecting these data continuously and annually, we were able to bring to publication in the journal of the American Medical Association just about two to three weeks ago, the results which demonstrated that, in fact, in spite the fact that we think everything is so wonderful, that rates of subsequent heart attack, stroke and death remain high throughout the world and including the United States.

Dr. David Meyerson: Let me just mention for our listeners so that they can link this, as clinicians we often talk to our patients about their family histories, about their blood pressure, about their cholesterol, about their history of tobacco smoking, their exercise habits and whether or not they're diabetic, but in the Reach registry and other trials, we're now seeing that if somebody has a manifestation of peripheral arterial disease, we are now telling them that this is -- if you have P.A.D., if you have claudication or diminished pulses in your legs, this should be a concern -- this should be considered a coronary heart disease risk equivalent. Is that right?

Dr. Alan Hirsch: Absolutely right. So regardless of where an artery is damaged, once there is evidence of damage, again regardless of where, whether it's in the heart, the brain or the legs, you remain at some increased risk for the rest of your life and you want to develop this partnership with your physician to lower that risk as best you can. A coronary risk equivalent.

Dr. David Meyerson: Let's go even a step further because I want -- we talked about trying to maybe push you on this topic --

Dr. Alan Hirsch: Please.

Dr. David Meyerson: -- because this may be a coronary risk equivalent like saying that you have high blood pressure or you have high cholesterol, it needs to be treated, but once you've actually developed blockages in the arteries in the lower extremities, this in my judgment should even be considered a marker for active, existing disease in other areas of the circulation. Would you agree?

Dr. Alan Hirsch: Well, you've actually said that very well, so I'll expand that point for the listener. The other thing that Reach observed is not only is this no longer merely a risk factor, the presence of a history of symptomatic disease from a prior stroke or a prior heart attack or even claudication or leg muscle discomfort from P.A.D., not only is this evidence in your circulation a marker of ongoing risk, of continued risk, but the number of beds affected also, maybe this is not surprising, the number of beds affected effects that risk as well, so --

Dr. David Meyerson: When you say the number of beds affected, you mean the vascular beds, the areas of --

Dr. Alan Hirsch: The vascular beds, so if you only have disease in the heart, there's a particular rate, but if you add also blockage of the leg arteries, that rate markedly increases.

Dr. David Meyerson: Now work with me just a second because I want to bring you right back to this point, but I want to do it by reminding our listeners about that test that you want every clinician to be doing when they evaluate somebody for circulatory disease and that's the ankle-brachial index. So in twenty-five words or less, what's the ankle-brachial index?

Dr. Alan Hirsch: We enjoyed the phrase on our last PodCast that the ankle-brachial index is sort of like the EKG of the legs. The ankle-brachial index is designed to measure with a simple office blood pressure cuff, the higher blood pressure in either arm and the blood pressure at the ankle arteries and it's a comparison of the ratio so as I talked to you on this PodCast, my arm blood pressure might be one hundred over something and my leg blood pressure hopefully is equal also one hundred over something because of the absence of any blockage in my arteries.

Dr. David Meyerson: And so if one does the math, one above the other, the ratio is going to be one, right? One point zero.

Dr. Alan Hirsch: Right. One hundred divided by one hundred is one point zero.

Dr. David Meyerson: One point zero and if the pressure in legs is lower than the pressure in the arms that is a warning sign, is it not?

Dr. Alan Hirsch: That is a sign there must be a seventy percent or greater blockage, that's the only reason that could happen and that means you're no longer theoretically at risk at some point, you actually have artery disease and you are at high proximate risk of heart attack --

Dr. David Meyerson: And this is again the message I want to get to our listeners, a simple test, this ankle-brachial index, taking the blood pressure in the arm comparing it with the pressure in the legs, it should be done in both legs to compare --

Dr. Alan Hirsch: Correct.

Dr. David Meyerson: -- and if the ankle- brachial index is less than point nine, is that right? It indicates at least a seventy percent stenosis. Right?

Dr. Alan Hirsch: That's correct. And we actually learned very large population studies that any decrement even values between zero point nine zero one point zero are a risk, but we define even a ten percent fall as zero point nine ankle-brachial index ratio as the disease and for the listener --

Dr. David Meyerson: Now Alan, this is ninety percent sensitive and ninety-five percent specific for peripheral arterial disease. Can you explain what those numbers mean, the ninety percent sensitive and the ninety-five percent specific?

Dr. Alan Hirsch: With a grin, I'm going to make this a nonscientific explanation for the listeners.

Dr. David Meyerson: That's your job.

Dr. Alan Hirsch: When the test is abnormal that there's a ninety percent likelihood that you actually have the disease, the test is accurate. There is no perfect test for any particular illness. All tests have an error rate, but that's very, very good and it means when the test is normal, you don't have the disease. In other words, by simply measuring blood pressure, you accurately classify people to those who have truly normal circulation or truly abnormal circulation.

Dr. David Meyerson: And then if they have the symptoms like intermittent claudication such as you know, you walk and you get pain in your legs or the abnormal examination of the pulses, this heightens your suspicion even more.

Dr. Alan Hirsch: Right. So, going back to the --

Dr. David Meyerson: Let me -- I've got to take you one more place though because this important. I want the listeners to understand this. A low ankle- brachial index, this simple test that the doctor can do in the office at minimal cost and zero discomfort and risk, if the ankle-brachial index is less than point eight, isn't the risk of subsequent coronary events of all types, blood vessel events of all types, six times greater than that in the general population?

Dr. Alan Hirsch: That's generally correct. We're not talking about a small risk, we're talking about a high risk.

Dr. David Meyerson: This is staggering information. And if somebody told you that you could get this information and know that you were driving sixty-miles per hour into a brick wall and find out early enough to apply the brakes or make a turn or do any one of a number of things, this would be critical information.

Dr. Alan Hirsch: At almost no cost, at essentially no risk, I would think that turning on the headlights before the deer is in the road ahead of you would be a wise thing to do.

Dr. David Meyerson: So we should literally be standing on the clinical mountaintops telling patients and healthcare providers how important this is.

Dr. Alan Hirsch: I agree.

Dr. David Meyerson: It reminds me of that joke, what's that -- there ain't no freaking french fries, that's what I've been trying to tell you. So this has been -- you know, it sounds like I'm trying to extract this information from Dr. Hirsch, but the fact of the matter is that he's been a national leader in this area for many years now and we really should be standing on the clinical mountaintops telling patients not to ignore symptoms relating to peripheral arterial disease because again, it's a marker for disease in other areas of the body. It could be your biggest and best and possibly even earliest clue that you have high risk for subsequent stroke or heart attack or death and it could be that clue that could get you to the proper -- into the proper clinical hands to avoid that terrible risk, Alan, wouldn't you say?

Dr. Alan Hirsch: So we're asking consumers, we're asking the public, we're asking people who are at risk to be proactive to be advocates for their own health and that of their loved ones and to ask their physicians if they are in a category where an ankle- brachial index or ABI test should be performed and to get it done.

Dr. David Meyerson: Alan, Dr. Kerry Stewart, Professor of Medicine at Johns Hopkins and my sidekick for many of these is in studio with us and I think he has a question for you as well.

Dr. Kerry Stewart: I don't really have a question as much as I'd like to just get back to the whole topic of clinical trials for a second. I think Alan made it very clear that volunteers on the part of patients is extremely important and for those listeners out there that like to participate in clinical trials, there is a website that the government has called and that provides regularly updated information about federally funded, privately supported clinical research in which patients can look for a particular condition that they might have and make contact with the investigative team and see if they are eligible to be a participant of a study and that would be a tremendous contribution, not only to perhaps helping themselves, but also as Alan clearly pointed out, making a contribution to science and society.

Dr. Alan Hirsch: And Kerry, thank you. They also, they also might go to the Vascular Disease Foundation website where there's also a clinical trial listing for vascular trials in particular.

Dr. Kerry Stewart: That's right. We started to post those recently and thanks for reminding me about that.

Dr. David Meyerson: Well, that's wonderful. I'd like again to remind everybody that those types of research -- one never does research on an individual without their absolute, the clearest possible expressed consent, they have to be in laymen's language and these institutions that you see on these websites with National Institutes of Health funding are of the highest quality and they have to report not only to their own institutions, but to the NIH as well and these are -- these institutions are doing very high quality research and they are asking questions that we truly don't know the answer to. I want you to remember that any manifestation of peripheral arterial disease should be considered a coronary heart disease risk equivalent. You should consider that you have that, if you have peripheral arterial disease, you should be talking to your cardiologist and your internal medicine physician and your family practitioner to say, "Doctor, I have this, do I have this in other areas of my body?"

So my special guest has been Dr. Alan Hirsch, he's the Director of Vascular Medicine program at the Minneapolis Heart Institute, Professor Epidemiology and Community Health at the University of Minnesota School of Public Health. Also with me in studio engineer producer, Professor of Medicine, Dr. Kerry Stewart. Until next time, I'm Dr. David Meyerson for the Vascular Disease Foundation. Thanks so much for listening.


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