Heart Attack Recovery: Understanding the World s Smallest Heart Pump Webcast February 4, 2009 Antony Kim, M.D.

Transcription

1 Heart Attack Recovery: Understanding the World s Smallest Heart Pump Webcast February 4, 2009 Antony Kim, M.D. Please remember the opinions expressed on Patient Power are not necessarily the views of Oregon Health & Science University, its staff, our sponsors, partners or Patient Power. Our discussions are not a substitute for seeking medical advice or care from your own doctor. Please have this discussion you re your own doctor, that s how you ll get care that s most appropriate for you. Introduction Hello and welcome to "Ask the Experts. I m Andrew Schorr. These are the programs we do every two weeks connecting you with a leading expert from OHSU and talking about a significant medical topic. Today we re talking about a really hot area of cardiology. Now in the past we ve talked about just the amazing technology that continues to improve to help the electrical system of the heart and for the heart to beat properly, but there s a whole other side of the heart and that is how well it moves blood through and actually the whole circulatory part of it. So joining us to understand some innovations in devices there that they re now using at OHSU in studying further to help people for instance who have had a heart attack or who ve been told maybe they have inoperable heart disease. Joining us is Dr. Antony Kim. He is Associate Professor of Medicine at OHSU. He s the new Director of the Heart Failure and Transplantation area at OHSU. Dr. Kim, thank you so much for joining us. Thank you for having me. Dr. Kim, so as I said, we ve talked with electrophysiologists about all the more sophisticated devices to zap the heart or put impulses where they need to be or just get the electrical system of the heart working right, but of course we worry about coronary artery disease, people s hearts become weak and don t pump well, or can t pump well enough for them to undergo a procedure, so I imagine this whole area of circulatory support is an exciting one in cardiology. Yes, that s right Andrew. One of the big areas of growth in our healthcare population is the development of heart failure or weaker and weaker hearts, and so there s really been a need and a lot of technological advancement over the last few years in trying to provide some level of support that will help the circulation system to improve the amount of blood flow that the heart is unable to provide. So these 1

2 devices are starting to become more and more on our radar, and basically its main function is to give that additional amount of circulation support that the heart lacks. New Technologies in Cardiology Now let s talk about a situation. So someone comes to OHSU. They re having a heart attack, and they re pretty weak, and it s thought normally let s say you d like to do some sort of cardiac catheterization, go in there and clear out the arteries. I understand there are some people where you re concerned that their heart is just too weak for that. So what kind of device do you have now that maybe could help that person? There are a couple of different devices that are on the horizon and a couple that have already begun to be looked at that have been approved by the FDA. The devices are percutaneous devices, which just means that they are a little less invasive. Usually the point of insertion is through the skin and into an artery, but these small devices are now becoming available to really help those patients that you ve mentioned that really are very high risk without some sort of additional support. So there is now a new device that s available by Abiomed called the Impella device. It s a very nifty little device that is essentially like a long straw with sort of a curly tip that sits in the heart and helps to take some of the blood that s in the heart and shoot it out into the rest of the body. So by doing that is that just allowing someone s weakened heart to just sort of get a rest? It doesn t have to do all the work itself and more blood can be moved that the body needs? That s right Andrew. So the devices basically have the same type of theme, which is that the heart is unable to basically provide that blood flow to the rest of the body, and so these devices are put in, usually they are temporary, but they re put in to take some of the blood that sits in the heart that s not able to get to the rest of the body and basically sends it forward into the rest of the body. So we re talking about maybe not, this isn t nanotechnology or maybe even micro, but it s certainly, at least inside the body, miniaturized pumps. Really this is a whole new innovation in cardiology I would think. 2

3 Right, right, it certainly is. These devices are very small, and they are still temporary meaning that the idea is to eventually wean patients or take patients off of these devices, but they are small enough that they can be placed, for instance, at the bedside and yet they provide enough strength and power to generate quite a bit of blood flow. All right, so there s that example I talked about if somebody came to the ER and needed a catheterization procedure with the addition of these miniature pumps that you can insert through the groin to the heart, you re now able to help that person where maybe there was a concern that you couldn t before. So it seems to me that could be lifesaving. That s right, especially in patients that are considered very high risk for going into their arteries and opening up blockages. There are a few scenarios for instance where very large coronary artery vessels are blocked or partially blocked where in the past cardiologists would have basically been apprehensive to proceed forward with unblocking them or opening them up, and now with devices such as these there s a little bit more backup support to make sure that the heart continues to generate good blood flow or cardiac output as we might say for the rest of the body while an intervention or some sort of procedure is being done. And the idea is often people who have these problems may be older or more feeble where certainly there are other candidates for bypass surgery and major heart surgery, but the idea is that if you can do it in the cath lab that may be much less invasive? That s right. I think that most people would agree that it would be a lot easier to tolerate a procedure where there is a small stick into a vessel in your leg as opposed to a procedure where the chest has to be opened. So this is really an example, I know you re new to OHSU, and they re delighted to have you, but this is an example of the kind of research and innovation that goes on there I would think. Yes. In fact there are several additional trials that are going on at the current time that are looking at some of these various devices, and some of them are looking at whether or not to expand the indication, for instance whether or not these devices might be helpful for severe, advanced congestive heart failure or if patients develop cardiogenic shock. So scenarios where the heart is very sick, the heart is very weak 3

4 and unable to generate any kind of forward flow, and these devices may have an indication. So some studies are currently being looked at. Now just so I understand the current use. So you mentioned it s temporary, so let s follow that example of the person who comes to the emergency room, they re in pretty bad shape, they re a high risk patient, but with the help of a pump that you can insert through the groin to help the heart move blood you can proceed and try to unblock major arteries. So now they go to I imagine the cardiac intensive care unit as their post procedure. How long might they have this unit in, and what would happen from there? Typically the idea is to rest the heart, so sort of the goals of a device like this are to rest the heart during that period of time when it has been damaged or injured and to allow the heart to sort of recover. So that time period can vary patient to patient, but typically these devices are put in for a short amount of time, usually in the setting of a couple of days. It has been looked at. For instance another device called the TandemHeart, which I believe is manufactured by CardiacAssist, that device has been looked at all the way up to two weeks. So there are times when the heart might take a lot longer to recover, and so it might stay in for a little bit longer, but these devices are currently being looked at as temporary in the matter of a couple of days to even a couple of hours during the procedure. It s basically to give your heart a break while through other interventions you try to improve blood flow, unblock arteries, and give the heart a chance to recover. Right. Heart Failure and Cardiogenic Shock All right. Let s sort of move forward with this a little bit. One of the things that maybe many people don t understand that you mentioned at the outset is the term heart failure and before I start doing all these programs I used to think well heart failure is like pass/fail, the heart either works or it fails and then you re dead, but when we talk about heart failure, we re really talking about the heart not beating efficiently, right, not moving the blood through efficiently, and as with some of the problems we have in our society where people are sedentary, obese, diabetes, etc., this is becoming more common isn t it? Yes. That s right Andrew. So the way I typically like to think of heart failure is that it s an economic problem. It s a physiologic economic problem where it s a supply/demand mismatch. 4

5 For those in the audience who took their macroeconomics the idea is that there is a demand that the body has for oxygen and in a normal performing heart the heart can deliver that or supply that to the demands of the body, but there are some patients that eventually develop worsening heart failure where the heart can no longer supply what the body demands, and that sort of leads to this syndrome of heart failure. And then you mentioned one other condition, was it cardiac shock? Right, cardiogenic shock. What does that mean? Cardiogenic shock is a very serious state where basically the heart is unable to do what its main function is, and so because of the fact that the heart has basically stopped being able to generate that supply of blood and oxygen the entire body begins to shut down, and what I mean by the body is the major vital organs of the body begin to completely shut down, so it s gotten to such a state that the kidneys, the liver, and eventually the brain begin to shut down. Evaluation and Diagnosis You don t want to get to that point I m sure. Dr. Kim, let me ask you about OHSU a little more generally related to heart failure for example. So now we ve talked about these innovations that you re studying and using related to these very small pumps for the heart to give the heart a rest and can be implanted in a very minimally invasive way, but prior to that you ve had various drug therapies on one side, and maybe in extreme cases you ve had heart transplantation. So I know you do it all at OHSU. How do you decide which approach for which patient? I think that s a fantastic question Andrew because I think that very often the general perception is that it s very simple algorithms that we follow in what each patient should receive, and I think that it s more complex than that. There are a number of different factors that help us in that decision making process, but I think one of the important parts of evaluation of the patient is that it really I think is beneficial for the patient to receive a full, complete cardiac evaluation to really know what the etiology or the cause of their main problem is because oftentimes if you don t have the right diagnosis it s hard to give the right treatment, and so if somebody comes with this sort of diagnosis of having heart 5

6 failure, well the causes of heart failure are multiple, and it could be because they have a blocked artery, but it could also be because they have anemia. So there are extremes in sort of what could be causing the heart failure, and I think the key is to sort of do a proper evaluation, and once the evaluation is completed then I think that the steps become clearer in what each patient needs. So I think that that initial step of sort of point of care where a patient arrives and really undergoes this level of diagnostic workup is really the most important part of the entire evaluation. I don t think people understand that as much because I think, right, you say well, I was told by a doctor, maybe on an initial workup that I have heart failure, but you re right understanding what the cause is has everything to do with what the approach is to deal with it, and I know you re really serious about that in cardiology at OHSU. What are you dealing with? Yes, you know, I ve kind of a funny story where I once had a patient that came to see me in the clinic, a patient that came for the first time, and when I entered the room the patient said that they were here to schedule their heart transplant, the idea being that they knew that transplants were being done here and therefore they were ready to go forward with getting one, but I think that again sort of begs the point that we really need to do a better job of doing a full evaluation and making sure that we don t miss anything because there are some treatments for various cardiac diseases that are very straightforward, and you don t want to miss those things in lieu of doing a much bigger operation or procedure that may or may not have been necessary. Right, well I think the idea that it could be something fixable is very compelling. Now let s talk about that. So on the one hand you may have somebody who s been very feeble, and you need one of those little miniature pumps while you unblock the arteries and do all you can for them. I know recovery is very variable, but give us an idea, and give people maybe some hope, if you will, of if they can get out of the hospital, what is the variety of scenarios of going back to hopefully a decent quality of life? I think that there are clearly established standards for how we ought to treat patients that are chronically ill, and the scenario that you re mentioning Andrew is one where you might have a heart problem but it s chronic, it s been going on for a good bit of time, and it most likely will be persistent. Therefore in those cases I think there has been considerable advancement in the last two decades on the medical management of these chronic diseases, especially cardiac diseases. 6

7 So one of the, I think, most important messages that cardiologists are constantly discussing with their patients is compliance with their medical therapy. If they have been prescribed medication to continue that on a routine basis without missing them, and so the treatment for chronic diseases usually is medical management while the treatment for these acute events on top of the chronic disease is really when the diagnostic cardiologist needs to be on top of their game in being able to figure out exactly what s going on so that they can properly treatment them. So I think the chronicity part I think has been well established. It s really these acute events that develop that really need a lot of attention, a lot of acuity, a lot of diagnostic competence by the cardiologist. Drug-Eluting Stents I have a question that has sort of been hanging around for the last year or so. So beyond the improvements now that you have in pumping the blood through the heart with these small devices as you re in the cath lab, one of the other things that s going on in the cath lab are insertion of devices, for instances over the last few years drug-coated stents, and there was a variety of publicity about when should these be used, how reliable they are, you mentioned about people staying on medical therapy, and there were some people who kind of forgot or stopped, and then there were some bad outcomes sometimes, so it was reviewed by the FDA. From where you sit, what s the use of those devices in the arteries that supply the heart now and how confident are you about them? Andrew, you ve touched upon one of the hot topics and controversies of cardiology, and so I think if you talk to ten different cardiologists you might get ten different responses. I m very close to this data, and a lot of the publications regarding this topic, so I ll give you my opinion about it. Right, sure. The main concern over the last couple of years has been in the area of drug-coated stents and the correlation that it has with complications that occur after a year or much later after the device was implanted or deployed, and the question is whether or not these events are related to the particular device itself or the stent itself or if it s related to other issues, and I think that there s very likely a combination of different factors that are going on. The drug-coated stents have been very heavily scrutinized over the last few years because of the fact that there seems to be according to whichever data set that you look at a possible trend that these devices have towards a very unfavorable and potentially catastrophic outcome after a couple of years, but if you look at other 7

8 data points or other data sets, like registries, it s not as clear. It could be occurring in both drug-coated stents or in bare metal stents, which don t have any drugs that are eluted. So it s really not clear whether or not the specific device that has these drugs coated on them are related to these catastrophic events, but I think that the sort of short answer to it is that there needs to be a lot more investigation about this and the actual percentage of these really bad events is very, very small in general. It has, however, affected some of the guidelines that we follow as cardiologists, and so the typical patient that doesn t have any major adverse risk for developing bleeding are now recommended to be on a platelet inhibitor, namely a ADP inhibitor, for as long as possible after the deployment or implantation of one of these drug-eluting stents. So that has changed in a large part because of this big question mark of is there a correlation between these small devices and eventual bad outcome. I think that s important for the public to understand. Cardiology is a highly technical area, and the heart and blood flow and electricity around it, these are complicated issues, and as scientific development and medicine grapple with it there are often questions to be studied long term, and that maybe takes us full circle. So you re excited about these miniature devices to help give the heart a rest on a temporary basis particularly for people who otherwise couldn t have a procedure. How long will it be before you get more familiar with this? You re seeing some benefit now, and like you said this Impella device has been approved, so will this be just an area that will continue to be looked at and be tweaked and improved? Where are we headed? Yes, absolutely. I think that the devices will continue to be improved upon, and particularly these areas of research are very much technology driven, and so the development of these different devices only will continue to get better and better over time. The real question though will be how do these devices improve outcome because the devices might get smaller, they might get niftier, they might be more portable, they might last longer, but the real question will always be do they actually improve mortality and morbidity of patients, and I think that that s really where the big clinical studies need to be performed on these devices. We can certainly make the devices better, but can we improve overall patient and overall healthcare by using these devices, and I think that that s the piece that we re most interested in because while having the newest toys to use are great for certain parts of patient care because they are usually an improvement on convenience and less pain and other complications, but ultimately we want to know if these devices improve outcome. 8

9 I think that s an important point to make as you mentioned about toys. Cardiology has a lot of toys or exciting devices, and many hospitals around the country and sometimes healthcare professionals get excited about all that, but it s very reassuring from you being one of the directors at OHSU to say what it s really all about is does it improve the prospect of life and a long life for a patient, and I think that s really what it s all about. Dr. Antony Kim, the new Director of the Heart Failure and Transplantation area at OHSU, I want to thank you for joining us and talking about really I think some very promising areas of cardiology as unfortunately we have this growing heart failure problem, but it s reassuring to know that there s progress being made and OHSU is at the forefront. Thanks for being with us. Thank you very much for having me. This is what we do on our "Ask the Experts" program produced by Patient Power. I m Andrew Schorr. Remember, knowledge can be the best medicine of all. Please remember the opinions expressed on Patient Power are not necessarily the views of Oregon Health & Science University, its staff, our sponsors, partners or Patient Power. Our discussions are not a substitute for seeking medical advice or care from your own doctor. Please have this discussion you re your own doctor, that s how you ll get care that s most appropriate for you. 9