New Research for Babies with Congenital Heart Defects
Alexa Craig MD
Each year, 40,000 babies in the United States are born with Congenital Heart Disease, and one or more surgeries are typically required during the first year of life to correct their heart defects.
Dr. Alexa Craig was recently awarded a KL2 Career Development Awards through Tufts Clinical and Translational Science Institute. The grant will allow Dr. Craig to continue her work on slowing down the rate of rewarming in babies with congenital heart disease following surgery. The idea is that slower rewarming will prevent fever and help improve developmental outcomes.
Listen in today to Dr. Alexa Craig, she is a neonatal and pediatric neurologist with Maine Medical Center.
Dr. Alexa Craig (Guest): What we're seeing is that the surgical advances that have been made in terms of taking care of these children have been absolutely phenomenal and we can do -- 'we' meaning the surgeons and the cardiologists--amazing surgeries to keep these children alive and actually thriving into many, many more longer years than was ever anticipated several decades ago. What we realized, though, is while we're able to correct the heart lesions, their outcomes, developmental outcomes are not always as ideal as what we would like them to be. So, there's a lot of new research being done to try to improve those developmental outcomes. So, what we designed a study for here at Maine Med was to change the way in which the babies' temperatures were managed in the postoperative setting, hoping that by keeping their bodies a little bit colder for a little bit longer and, essentially, preventing them from having fevers that we would be able to improve their developmental outcomes years down the road.
Melanie: This is so scary for parents to hear this. So, speak about now, what is the next sort of step for them and how do you reassure parents that you're working on this? Tell us about your study.
Dr. Craig: Yes, it is a scary thing to first, be pregnant and find out that there's something wrong with your baby's heart and find out that your baby's going to need surgery and, sometimes, several surgeries, to correct those defects. I work a lot with parents who are pregnant and once the baby is born, about kind of really playing a huge role in educating them about the possibility of abnormal developmental outcomes. While that sounds like a real negative, I try to spin it in a positive light because, knowing that something could go wrong allows us to identify it early and then do really high-intensity kind of treatments like occupational therapy, speech therapy, or physical therapy--any of these different things--to try and help improve the outcomes. So, it's really trying to stay focused on the positive: knowing that there could be a problem and then looking at it through that lens.
Melanie: How do you reassure parents with the risks of maybe a perioperative stroke or that their child is about to have a bypass kind of surgery that they only think of in a 70-year-old male?
Dr. Craig: That is definitely terrifying and we talk really separately about the surgical risks of going on bypass and those risks are all discussed with the cardiothoracic surgeon and then, of course, there' are anesthesia risks. The family has those conversations with an anesthesiologist and then, to add on to all that immediate scary stuff, then if I'm involved and we have a conversation, we talk about these longer-term risks. Big injuries like strokes are relatively uncommon in this population and the family doesn't have a choice to make for these surgeries. The child would not survive without these surgeries and so what has to happen is that we just hope that everything goes well and, obviously, the surgeons and all the members of the team do the very best that they can to try to make sure that the child doesn't have any of these kind of adverse outcomes immediately. Where this study comes in is that we know from a lot of research that's been done in babies in the neonatal intensive care unit--and these are baby who don't have congenital heart disease--we know if those babies are born in a situation where they're deprived of oxygen for a whole bunch of different reasons: the umbilical cord could be really tightly wrapped around their neck or something like that. We know that if we make those babies have a lower temperature for about three days, that after that period of being cold or, we use the term 'therapeutic hypothermia', we know that then the babies have a much, much better chance at having a normal neurodevelopmental outcome. They walk on time, they talk on time. Everything is really going according to the anticipated plan, not having cerebral palsy or epilepsy, or hearing or vision impairment, which is what used to happen when those babies weren't treated with the cooling treatment. So, what I did in kind of my idea that was really new and different was to try to take that therapy from the children in the neonatal intensive care unit and apply it to a different population of children, which are the ones who have the congenital heart surgery. It was a very natural thing to do because the kids who have congenital heart surgery have their bodies cooled in the operating room for protection of their brain, it's just that before my study came along, the old system was we re-warmed them very, very quickly and in my study, we re-warm them very slowly over 12 hours.
Melanie: So, what are you seeing now?
Dr. Craig: It's basically a very early, early study, so we've only done 14 children in the kind of first pilot phase of the project. What we were primarily looking for was to make sure that this idea was safe to implement in babies. We looked at a lot of different parameters like their blood pressure, their heart rate, and their respiratory rate, and whether or not they had any more incidences of infection or bleeding, how long they stayed in the hospital, how long they had breathing tubes--all of those different variables and what we found was actually that the babies who were on my treatment, they stayed a little colder a little longer, those babies were actually more stable from a blood pressure standpoint and from a heart rate standpoint and they actually stayed fewer days in the hospital. So, it seems like, at least in this very early--and I emphasize--very preliminary analysis, that it looks like preventing fever by keeping them a little cold seems to actually be overall beneficial to the whole system. The kids are just coming back this summer for developmental assessments. We're going to be doing Bayley-III testing, which is kind of, in its simplest analogy, like doing an IQ test on a baby. So, most of these kids are 9-12 months old now and we're looking to see how do they do on their vocabulary and how do they do on their motor skills? Are they walking? Are they talking? All that kind of stuff.
Melanie: So, are they? What is the outlook and prognosis for children that have this slower rewarming and what are you seeing? That's fascinating!
Dr. Craig: Yes. We don't really know yet. That's why we're having them come back for follow-up. All the indications during their inpatient hospitalization looked favorable for this procedure and it was very, very effective at preventing the children from having fever. I don't think I actually described what we do to keep their body temperature down. The baby is placed on what we call a 'cooling blanket', and the blanket circulates water at various temperatures in it to control the temperature of the child. What I like about it is it's a very minimally-invasive thing to do to just lay this baby on a blanket and then have such good control of the temperature. And I actually think that a lot of the benefit comes from preventing fever, because, believe it or not, when you're sick with having had a surgery on your heart and all of the things that go with it, it's really bad for your brain to also have a fever. And so the developmental outcomes are soon to be tested. I was very fortunate. I have just started on May of this year on a two-year federal grant to continue studying this. So, we're going to continue to recruit patients here at Maine Medical Center and possibly other institutions, if I'm persuasive enough in my arguments about why this should be done, and try to prove in a much bigger population of children that not only is this intervention safe but, hopefully, also that it's effective at improving developmental outcomes.
Melanie: Absolutely fascinating, Dr. Craig. So, in just the last few minutes here, give parents listening kind of your best advice, doing what you do for a living, and kind of giving them a little reassurance about if their baby does have a congenital heart defect, what you can tell them about your research, what you're doing there at Maine Medical Center.
Dr. Craig: So, what I would say to parents is I absolutely think that a child's brain and, particularly an infant's brain, is about the most phenomenal thing in the entire universe. It's so programmed to grow and develop and to learn that while, it's sometimes really, really sad to break bad news to families and tell them that something bad has happened to their baby, such as a stroke, like you mentioned before, I can also tell them that I've seen children who have had strokes who learn to walk, who learn to talk, who do these absolutely amazing things, even though they had brain injuries. So, I think the name of the game is early identification of the vulnerable child and putting lots and lots of therapy into the child to really maximize the opportunity that we have to help the brain grow and develop and re-circuit or rewire if it needs to. Children just seem to have this unbelievable capacity to get better, you know? The injuries that these kids have--if I had them, I'd be in a nursing home for the rest of my life and these kids just get better, you know? It's knowing it and supporting them the best way we can.
Melanie: It's great information and I applaud all the great work that you're doing, Dr. Craig. Thank you so much for all your hard work. You're listening to MMC Radio and for more information, you can go to mmc.org. That's mmc.org. This is Melanie Cole. Thanks so much for listening.