In-depth doctor’s interview with Charles D. Fraser, Jr., M.D., chief of congenital heart surgery at Texas Children’s Hospital in Houston, talking about the Berlin Heart, a pediatric ventricular assist device.
What is the Berlin Heart?
Dr. Fraser: The Berlin Heart is a heart assist device. It is a blood pump designed to support failing circulation in children. It sits outside the body and is connected to the heart and the great blood vessels through canals or tubes. It’s driven by a pneumatic compressor and it pumps the blood.
Can the Berlin Heart keep a person alive — a child alive — when their heart has failed completely?
Dr. Fraser: Two questions there. Can it keep a child alive when their heart is failing? Yes, the heart has to have some function for the Berlin Heart to work. In other words, it’s not replacing the heart, but assisting the heart. Now, we can do the lion share of the cardiac output, but the heart does have to have some function. One question that people often ask me is: are we taking the patient’s own heart out when we put a Berlin Heart in? No, the Berlin Heart is connected to their heart and is a ventricular assistance device. The terminology tells you that the Berlin Heart helps the heart without completely replacing it.
How much can the Berlin Heart extend a child’s life?
Dr. Fraser: We don’t really know what the outer limit of support is yet. We have had patients here at Texas Children’s Hospital and elsewhere in North America on the Berlin Heart for months. There are patients worldwide that I am aware of that have had this device supporting their circulation for over a year. Theoretically, it’s an indefinite prospect, but that is not how the device is designed. The Berlin Heart is designed to support the failing circulation until the patient receives a heart transplant.
Why is it so important to have something like the Berlin Heart?
Dr. Fraser: It is so important to have something like this because prior to this device becoming available, or potentially available, we didn’t have much to offer children with acutely failing circulations. There were only some very temporary options. ECMO or extracorporeal membrane oxygenation is one, but that has a very short potential duration of successful support, and when you have a desperate child with failing circulation, that patient is dying. The risk eventually for a heart transplant is left to the reality that donor hearts are a very precious and scarce commodity and most patients often times succumb to their failing circulation before a donor heart becomes available. For children, there just has not been technology available. That is not true for adults. There are assist devices that have been used very effectively for adults for over a decade, like left ventricular assist devices.
What is the difference between having an LVAD for an adult and something for a child?
Dr. Fraser: The difference between adults and children are myriad. In children there are size issues — children’s physiology is different, they have growth issues, their ability to recover is different. There is a tremendous difference between adults and children with heart disease. The technology of scale in children has been hard to overcome, but there are people that are working on that both here in North America and around the world. The Berlin Heart is kind of leading that chart.
What is the likelihood a child with a Berlin Heart will be bridged to transplant?
Dr. Fraser: We don’t really know the answer to that right now. We are collecting data and our perception is about three-quarters of the children that are supported with the Berlin Heart are successfully bridged to transplant, but that is very preliminary information and that is why we are investigating.
Is the Berlin Heart the most promising thing that you have seen?
Dr. Fraser: I would not say it is the most promising thing in terms of technology. There are a lot of really interesting technologies being developed. Many very smart people and wonderful cardiac centers are working on small circulatory assist devices at the Texas Medical Center. The Berlin Heart is one that is farther down the track and has already been applied to lots of people around the world successfully. It’s kind of at the head of the pack right now in terms of experience and that is very attractive to me to help take care of these children.
Is there a certain type of candidate that would be better than others to receive the Berlin Heart?
Dr. Fraser: Yes. We would not place the Berlin Heart in someone that we didn’t think had the prospect of recovering and successfully surviving a heart transplant. Now, there have been some patients — we have not had any here at Texas Children’s — but there have been some patients in the United States and around the world where the Berlin Heart was placed, their circulation was supported, their heart was rested, and then the heart recovered and the Berlin Heart was removed. That is a very exciting proposition. Like an adult with an LVAD, if they can survive a transplant, that makes them a good candidate.
Before the Berlin Heart, what were the options for children?
Dr. Fraser: The options were a struggle that usually meant being in the intensive care unit, typically on a ventilator with a lot of very intense medicine to support the circulation. Often times with declining, not only cardiac function but other end organ functions, the patient gets worse over time. When we get ultimate desperation and the patient is clearly just acutely dying, we would place them on this ECMO device or some form of temporary heart/lung assist. That is a very precarious arrangement and one of our beliefs is the Berlin Heart is a superior option and is what we need.
Would the Berlin Heart work like an LVAD some day, where patients might not even have to be in the hospital and can go home?
Dr. Fraser: That is a really good question. There are patients in Europe who have had the Berlin Heart and have been discharged from the hospital. I can remember when we starting in the venture of LVAD therapy for adults and that was thought to be way out there in terms of a proposition and now is accepted as a therapy. I cannot imagine that the same will not be true for children, but we are just at the start right now and we are very cautious with our patients. We are keeping them in the intensive care unit if they are on the Berlin Heart. Our next goal would be to start to transition them through the hospital. I think eventually there would be the prospect that some of these patients could be discharged home, but that is well down the track right now.
How young can a child be to have the Berlin Heart?
Dr. Fraser: Days … hours. That is to me one of the very attractive features of the Berlin Heart — it comes in different sizes. The smallest patient that we have placed it in was just around three kilograms or six and a half pounds. I am aware of a patient smaller than that in North America. This is an option that really is very unusual because it can support such a small circulation.
What made Derek a good candidate for the Berlin Heart?
Dr. Fraser: Well, Derek fits the criteria we discussed earlier. Derek was presented with failing circulation — cardiomyopathy — getting sicker and sicker, not able to eat and being really miserable. There was a lot of angst on our part about whether or not we were going to be able to keep him alive until he got a heart transplant. Ultimately, we decided that was not going to be the case and we gave him a Berlin Heart. It was successful. He was supported for a lengthy period of time and then transplanted.
How you seen Derek change since you first met him?
Dr. Fraser: It’s remarkable. First of all, he grew while he was on the Berlin Heart and it was pretty cool to watch. He was able to get good nutrition. Another thing we extrapolate from the patients that get LVADS who are in end stage cardiac failure, are subsequently better transplant candidates then they would have been had they been languishing, malnourished and what not. I think Derek was a better transplant candidate when he ultimately was transplanted because he was able to eat. He was ambulatory and off a ventilator and doing kid things.
If everything goes as planned for Derek and he recovers successfully from the transplant, is he just a normal kid?
Dr. Fraser: I don’t think it would be fair to say that children who have heart transplants are the same as kids that have normal hearts. He has a normally functioning, structurally normal heart, but it’s not his heart and the reality is heart transplantations face a lifelong issue of rejection or infection. He will be forever part of our family in the sense that he needs diligent follow up with our transplant cardiologists and medical team; however, patients who have heart transplants with very good qualities of life — which is our optimistic hope for him — do lead normal lives.
How good does it feel to see a little boy that probably wouldn’t be alive without the Berlin Heart?
Dr. Fraser: Oh, it’s extremely gratifying to have a patient like this. Here at Texas Children’s and other major transplant centers, we have watched children not survive because of heart failure and we know we could have gotten them a heart to help them through. To have a patient like Derek, that from our objective criteria would not have survived otherwise, and be able to bridge him through a heart transplant is extremely gratifying and it gives us confidence to go forward.
Is the Berlin Heart FDA approved?
Dr. Fraser: No, the Berlin Heart is not currently FDA-approved. But in May 2007, the FDA agreed to allow a three-year prospective study in cooperation with 10 U. S. hospitals and two Canadian hospitals, in collecting and reporting data on the safety and probable benefit of the pediatric heart pump. At the study’s conclusion, Berlin Heart, Inc. will present those data to the FDA for their consideration of approval of the EXCOR Pediatric VAD for use in the United States. The Berlin Heart holds a lot of promise for infants and children whose hearts are failing. It’s extremely gratifying to be part of such a collaborative study involving the FDA and the other leading heart centers around the nation in exchanging information that will ultimately benefit many pediatric heart patients.
Source: Medical Breakthroughs, 04-21-08
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