Selected Podcast

Heart Transplants in Children

February is Heart Month, and we're decked out in red at Children's of Alabama. Behind the scenes, our pediatric heart transplant team is a well-oiled machine, with extensive experience caring for children with advanced heart disease. Our transplant team combines cutting edge research and clinical expertise to produce the most modern approaches to care for our patients and their families. Dr. Wally Carlo, medical director of the heart transplant team, explains how the care we provide impacts children in Alabama and around the world.
Heart Transplants in Children
Featured Speaker:
Wally Carlo, MD
Waldemar F. Carlo, MD, joined the pediatric cardiology team at the University of Alabama at Birmingham (UAB) in 2010. He currently serves as medical director of the Pediatric Advanced Heart Failure and Transplant program and head of cardiac MRI imaging. Before coming to UAB and Children’s of Alabama, Dr. Carlo completed his pediatric residency training at Cincinnati Children’s Hospital Medical Center and his pediatric cardiology fellowship at Texas Children’s Hospital. Dr. Carlo’s interests lie in transplant-related patient care and clinical research; advanced therapies for heart failure; cardiac imaging including MRI; and management of children with congenital and acquired heart disease in both the inpatient and outpatient setting.

Tiffany Kaczorowski (Host): Welcome to Inside Pediatrics, a podcast brought to you by Children’s Hospital of Alabama in Birmingham. I’m Tiffany Kaczorowski. It’s February and that means we are decked out in red here at Children’s of Alabama to celebrate Heart Month. Dr. Wally Carlo, one of our pediatric cardiologists is joining us today. He’s an Associate Professor at UAB, the University of Alabama at Birmingham and Medical Director of the Pediatric Advanced Heart Failure and Transplant Program here at Children’s. Welcome Dr. Carlo.

Wally Carlo, MD (Guest): Thank you for having me today Tiffany.

Host: So, we’re talking about heart transplantation today because you’re the Medical Director of that program. And how often do you find out that a patient might need a heart transplant when the mother is still pregnant?

Dr. Carlo: Those are uncommon times. What we tend to find prenatally are babies who have really important heart conditions and those babies are then born here at UAB and cared for here at Children’s of Alabama and they undergo any number of high risk congenital heart surgeries early in life. In general, we have surgeries for most types of heart conditions that babies can be born with. There are very rare conditions that are not amenable to surgery or conditions wherein the heart muscle is very weak. And so those are the babies who are candidates for heart transplantation. We might have 15 to 20 patients per year in whom we think heart transplantation is an appropriate treatment option.

Ultimately, we average about 9 to 10 per year and for reasons we can discuss later, we wish we had more availability of donor organs to offer transplantation to some patients who otherwise might not make it to transplant.

Host: Okay. Are you trying to make sure that baby gets to a certain age before they can have a heart transplant? Do they need to grow a little bit before they can undergo such a surgery?

Dr. Carlo: Well there’s no minimum age again, because most babies we elect to try standard surgical operations, they don’t necessarily need a heart transplant when they are a seven pound baby. Though, in the past, yes, we have transplanted infants of that size. In general, these are patients who are presenting after a failed surgical palliation so they might be 9 - 10 pounds, they might be 20 pounds, 30 pounds and weights far above that. But in general, there’s no minimum weight for transplantation.

Host: Okay. And then what about your older patients, maybe adolescents, teenagers; what type of symptoms are they having?

Dr. Carlo: So, these are really patients that run the gamut. Some patients who are born with important congenital heart conditions and have undergone multiple operations but finally their heart is giving out and there is no further surgery available to them. So, those patients are appropriate candidates at that time for transplantation. And then you have other patients who’ve previously been healthy children and teenagers who all of the sudden present with the first symptoms of a weakened heart or cardiomyopathy that they may have had for many, many years but just did not demonstrate any symptoms until that time. Or maybe patients who have acquired a new infection of the heart and so for those patients, even though we haven’t cared for them previously; they quickly become our patients and we have different therapies to offer them including sometimes transplantation as an appropriate option.

Host: So, it’s really used as a last resort for obvious reasons. You want to try everything you can possibly do before undergoing such a big surgery.

Dr. Carlo: You’re absolutely right. Our goal is to keep patients alive and healthy with their own heart, with the use of medications, or other assist devices. Transplantation really is the last option. And a transplantation is not a perfect treatment, a transplanted organ does not last forever.

Host: Okay. And what about when a baby does undergo a heart transplantation; how long does that particular heart last?

Dr. Carlo: Well these are really the most remarkable patients that we have in that infants tend to have a very forgiving immune system for reasons that we don’t fully understand but an infant transplanted successfully in the current era should be expected to have at least a 25 year graft survival meaning that you would expect them to be benefitting from that transplanted organ for two or three decades. And then, at that point, 25 years from now, we may have new options to treat them at that point.

Host: Now UAB has a very long history with heart transplantation. Can you give us a little bit of information about that and how strong the team is here? You guys have been doing this for a very long time.

Dr. Carlo: Right. So, I joined the team in 2010 or so. But the history predates my involvement by at least a couple of decades. So, if we go back to the early 80s, UAB was one of the early centers to employ pediatric transplantation. Dr. Jim Kirkland began doing them in the early to mid-80s and at that time, they would perform a pediatric heart transplant maybe three or four times a year. They were one of the few centers in the country doing that in that era. In the early 90s, the volume had increased a little bit. Dr. Bennett Pearce joined the program and Melanesia Hubbard, one of our fantastic nurse practitioners joined at that time also.

And really them two, Dr. Kirkland and a collection of other talented doctors and assistants really helped out for many years over at UAB. We were very fortunate to move here to Children’s of Alabama in 2012. And we have a really phenomenal team here with Dr. Bennett Pearce, myself, we recently welcomed Dr. Leslie Collins to our transplant program. And really a fine collection of nurse practitioners who are on the front lines of caring for these patients on a daily basis. The team didn’t stop there though. It continues with an assortment of other social workers, nutritionists, administrators, psychologists and many others that really help us take care of these complicated patients and assure them as best as we can of an excellent outcome after their transplant.

Host: So, posttransplant, you do have to give the patients some medications to try to prevent your body from rejecting that particular heart, right? And I would imagine there are a whole host of other things that parents have to take care of and do with those patients to make sure that that heart is up and running and is working well for that child.

Dr. Carlo: Well yeah and you make a good point in that these are complicated patients after transplant. So, we don’t just one day wake up and ask for a transplant this is a really involved process that involves a thorough evaluation of the patient and the family. We get to know them; they get to know us. And they get to really learn all about transplantation and what it entails because it is a life changing therapy. They do require immunosuppressive medications. These are medications that help the body not reject the organ. At the same time, those medications set up patients to potentially have infections that their body cannot fight off or other cancers or other complications. So, we really want families to enter transplantation being fully informed of the risks that come along with that treatment strategy.

Host: Let’s talk about now some of the innovations and research coming out of UAB and Children’s today and some of the collaborations that you guys are a part of that will help not only the patients here in Alabama but can help with patients everywhere across the globe.

Dr. Carlo: We are actually in the process of going back and studying the different immune system therapies that are done at around the time of transplantation and try to learn how our patients do in that first year after transplant. Are we doing a better job of preventing early rejection issues while at the same time not causing more infection or other complications for these patients. There’s other research where we look back at our transplant outcomes and try to learn to see who on the heart transplant waitlist is not having great success reaching transplantation, who is benefitting the most from different immunosuppressive strategies after transplantation. We just published a short paper about patients, the risk of rejection in the setting of low blood counts. So, we’re actively involved in transplant related research.

Going along with that, an important number of our patients, are patients who are born with hypoplastic left heart syndrome. So, these are really our highest risk babies. And we know that over the course of their lifetime; they are going to be different than you and me because they are going to live off their weaker ventricle or pumping chamber, this is the right ventricle as opposed to you or me, which we have a strong left ventricle. We anticipate that these babies when they grow up, they are going to have weaker right ventricles. And so hypoplastic left heart syndrome patients absolutely make up an important number of our transplant candidates and we would love to have a way to reduce the number of those patients coming to us and if we could help keep their function of their right ventricle better for a longer period of time; those patients will have a better quality of life and duration of life.

So, we are participating in a multicenter trial that’s run from up near the Mayo Clinic and this is a group of about 10 institutions. We recently joined and this is a study where we’re looking at muscle injections of stem cells into the right ventricle. The goal is that these stem cells will stimulate the right ventricle to become stronger or to remain stronger for a longer period of time.

Host: At what point are you injecting these stem cells?

Dr. Carlo: So, these are being performed at the time of the second surgery. As a reminder, these patients have three surgeries that they undergo. One, early in life at about a week old. The second at about four to six months old and the third at about four years old. So, we take them at the second surgery, and they undergo this surgery just like any other hypoplastic left heart syndrome patient undergoes but at the very end of the operation; we take a couple of minutes and we inject specially preserved stem cells that are retrieved from the patient themselves at birth. This is what’s called a phase II study and it is based on preliminary results from a phase I study done in the past couple of years.

So, we will then once enough patients are gathered from around the country; be able to go back and look and see whether we are keeping the right ventricular function improved comparing patients who do or do not receive the stem cell injections at the time of the second surgery. And we’re recruiting patients from our own center here but it’s important to know that not every center in the country is involved in this study. There might be just one or two centers in a region that are able to enroll patients. So, we are certainly open to having families contact us from around the region who may be interested in learning more about this treatment. Importantly, patients need to be aware of this before birth and patient advocacy groups for HLHS are doing a good job of spreading that word. This is important because when the babies are born, the OB doctors at the birth hospital need to collect umbilical cord blood. So, we take that blood and send it to the group up at the Mayo clinic that preserves those stem cells.

Host: So, remind me, do you find our often that a child has HLHS while they are in utero?

Dr. Carlo: Correct. These days the majority of them are picked up in utero. They are picked up by their local OB doctors or ultrasound technicians at around the 16 week or 22 week ultrasound. And then they are referred to us. So, we meet them in their second trimester, sometimes in the third trimester. And less commonly these days, no one picks up on it and we find out after birth.

Host: So, if someone wanted to inquire about that study, about that HLHS study; they can go to this website it’s //This email address is being protected from spambots. You need JavaScript enabled to view it. /">This email address is being protected from spambots. You need JavaScript enabled to view it. and then they would be referred to the center closest to them which in Alabama would be here.

Dr. Carlo: That’s correct. And from that website, there’s a link to all the centers that are participating including us and you’re right, if a family lives not too far away from here in the surrounding states; then it might make sense for them to be born locally, have their first surgery locally but then consider travelling here for the stem cell injection presuming that they collected the stem cells at the time of delivery. The delivery can occur anywhere. But the family needs to be aware of the diagnosis ahead of time, has to have reached out to the HLHS collaborative so that they can arrange for the collection kit to be sent and then for the cord blood to be collected at delivery.

Host: Okay. So, very important for that parent involvement and engagement so they can make sure that that happens. Anything else about the transplant program or the transplant team that we wanted to discuss? I know organ donation.

Dr. Carlo: We’re very excited about our program. And we have a fantastic team. we average about 9 to 10 transplants per year. We would love for children to be healthy and not need any transplants. But we are there for them and for their families and I think we provide a really tremendous service. There are patients who need a transplant, but the wait times are quite long because of lack of organ availability. So, we do encourage, and we have events throughout the year where we support organ donation and try to get that word out about the importance of increasing the organ pool so that our patients have a better chance at getting the therapy that they need.

Host: Okay so if anyone is interested in finding out more about this HLHS consortium and the stem cell study where should they go?

Dr. Carlo: The HLHS Collaborative is called the Todd and Karen Wanek Family Program for Hypoplastic Left Heart Syndrome. They can be reached by the email This email address is being protected from spambots. You need JavaScript enabled to view it. . We are available to be contacted directly and can help families make contact with that collaborative if needed.

Host: Well thank you so much Dr. Carlo for joining us today. We’ve learned a lot about heart transplantation and about some of the innovative things going on and research. So, it’s really wonderful. Lots going on.

Dr. Carlo: Well thank you Tiffany for having me today. Appreciate it.

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