Nicolas Madsen, MD: Hi there. This is Dr. Nicolas Madsen, Chief of Cardiology and Co-Director of the Heart Center at Children's Health in UT Southwestern. I am excited to be back today to introduce you to a new member of our Heart Center faculty, Dr. Megan Griffiths, who joined us just a few short months ago to help us address a clinical need that we think is particularly important for the patients of the Heart Center, and that clinical need is specifically pulmonary hypertension. We'll be talking a little bit about pulmonary hypertension, what exactly that means, why it requires unique expertise to care for it, and why Dr. Griffiths and the team that she's building is so perfectly ready to help these children who have unfortunately quite pressing, time-sensitive needs. So with that, Dr. Griffiths, thanks so much for joining us today. I really appreciate your time.

Megan Griffiths, MD: It's a pleasure to be here. Thank you for having me, Dr. Madsen.

Nicolas Madsen, MD: Yeah. You're very welcome. Well, I think before we get started and, if you're okay, I'm going to call you Megan. Does that sound okay? You have to call me Nicolas in return, however.

Megan Griffiths, MD: That sounds great, Nicolas.

Nicolas Madsen, MD: Good, good. Megan, tell the audience a little bit more, just foundationally, about pulmonary hypertension. What is PH exactly?

Megan Griffiths, MD: So, PH just really means high blood pressure in the lungs. So, people talk about hypertension, high blood pressure that you measure with a cuff when you go to your regular doctor's office. This is high blood pressure in the lungs specifically. And just like with regular high blood pressure, your heart has to pump harder. In this case, the other side, the right side of your heart, has to pump harder against this high blood pressure.

Nicolas Madsen, MD: Excellent. And so, it seems, as I know it and I think probably the audience is becoming more familiar with pulmonary hypertension, which we'll also refer to as PH, it's a subspecialty field in particular within pediatrics. How does someone like you with a cardiology background become particularly interested in PH? And can you share a little bit about your journey to becoming an expert in this field?

Megan Griffiths, MD: Of course. So, PH on its own is actually quite a rare disease, but it also happens to a lot of kids who have other diseases. And specifically, about 50% of our kids with PH actually have congenital heart. So, it's a natural fit for someone who's a practicing pediatric cardiologist.

The other thing is that really the main focus of pulmonary hypertension treatment is on taking care of the heart and preventing heart failure. So in that sense, it's really, really important to have that cardiology background and experience when you're treating pH.

Nicolas Madsen, MD: So, Megan, you're suggesting that unique expertise is necessary. What is your background exactly?

Megan Griffiths, MD: So, I'll give you the long version. I am from Colorado. I did my medical school at the University of Colorado. I ended up doing my cardiology fellowship at Johns Hopkins, which is where I got interested in pulmonary hypertension. And then, I did additional subspecialty training just in pulmonary hypertension at Columbia. So, I'm a pediatric cardiologist, but I focus exclusively on treating children with pulmonary hypertension of all types.

Nicolas Madsen, MD: So, you mentioned a moment ago that pulmonary hypertension is a rare disease, but that it can uniquely impact infants, children, young adults, adults with congenital heart disease. Can you expand a little bit on that relationship between congenital heart disease and PH?

Megan Griffiths, MD: Yeah. So, the classic, what we call idiopathic pulmonary hypertension that doesn't have any other issues associated with it, that's pretty rare. But for children with congenital heart disease, there are many different reasons to get pulmonary hypertension. Many of our children who have large holes or shunts in their heart, the increased blood flow can cause injury to the blood vessels in their lungs and cause pulmonary hypertension. And then, a whole new emerging field is for our children with single ventricles who have had a Glenn or a Fontan operation. They have to have very, very low blood pressures in their lungs for that physiology to really work for them. And the thing is that pulmonary hypertension can make these kids very, very sick and really get in the way of them being able to move forward, them being able to get their surgeries that they need to repair their heart disease or to be able to really function and have a full life. So when we treat that, we improve their quality of life.

Nicolas Madsen, MD: Megan, before we talk a bit about the types of treatments that you employ and why those treatments require your particular expertise, can you talk a little bit about other pediatric healthcare populations that are impacted by PH?

Megan Griffiths, MD: Yeah. So, a couple of our biggest populations are neonates or babies. So, we have large numbers of babies nowadays who are born prematurely and our neonatologists are very skilled and getting more skilled and able to look after these babies at younger and younger ages. But those babies are born with very immature lungs and many of them develop pulmonary hypertension, which is quite a severe complication. So, they really need someone focused just on that to help move them along and get them out of the hospital.

Along with that, our kids who are born even full term, but have some major problems like something called a congenital diaphragmatic hernia, they tend to be very, very sick in the first few days of life from very severe pulmonary hypertension. And then, there's this whole group of people who we call PPHN, persistent pulmonary hypertension of the newborn, which can be various things. It can just be that it was a really difficult delivery. And those babies can have persistent pulmonary hypertension the first few days of life that can make them extremely, extremely ill. So, having dedicated, specialized care to help take care of those children in the best way possible, I think, really improves their outcomes.

Nicolas Madsen, MD: Yeah. So you know, it is clear that pulmonary hypertension is a field that involves uniquely vulnerable or medically fragile pediatric population in particular. What do you do for them? How does a person with your expertise uniquely help these more vulnerable patients?

Megan Griffiths, MD: So, all pediatric cardiologists and pulmonologists are taught about pulmonary hypertension, so everybody knows a little bit about it. But being subspecialized in it, it's all that I think about all day and night when I'm at work. So, you start to get a really, really good understanding of how the heart works with the lungs, how they interact together, and how you can influence that.

The first thing I think about is instead of just is there pulmonary hypertension, is why exactly is there pulmonary hypertension? Because there's all these different possible diseases. And if I can figure out the why, then I can treat that specifically and be more successful.

Then, the second thing is there's been major advances. There's a huge research community in pulmonary hypertension that's been making major advances over the last 10 or 20 years. And we have a lot of new medications, new therapies, new ways of doing things that are sometimes a little bit complicated to use and do. And so, I can bring those easily to the bedside to all these children and give them an option for the newest possible treatment or treatment combination to fit their specific disease.

Nicolas Madsen, MD: And are there medications that are uniquely at your disposal, given your background and your training?

Megan Griffiths, MD: Yeah. Probably, the most obvious one is a class of medications called prostacyclins or prostanoids. They're a very, very strong pulmonary vasodilator. And I have these available inhaled, I have IV continuous infusions, and now also even some oral medicines. They're not commonly used in general pediatrics or even in general cardiology or pulmonology, because they are quite difficult to use and especially manage as an outpatient. But if you're a pulmonary hypertension specialist, they are kind of your bread and butter of your arsenal. Some things that are really helpful, especially with the inhaled medicines, those PPHN babies that I mentioned, the standard medicine that everybody uses at every children's hospital or NICU is something called inhaled nitric oxide. That only actually works for about half of babies. the other half of those babies really benefit from some of these inhaled prostanoids. And so, that's something we have readily available here to give to those babies right away.

Nicolas Madsen, MD: Great. We are certainly glad that you are here and we're really glad that you're helping us take care of these patients. I'm curious as to the future. What does the future of PH management look like to you? Do you expect the patient population to grow and their needs to evolve? And then, maybe we can talk a little bit about some of the research that you are well known for that has particular PH implications.

Megan Griffiths, MD: Yeah. So, I think the future of pulmonary hypertension is very exciting. I think the future for us is precision medicine, really targeting what a patient's disease is, what's their risk, and then targeting their treatment to that, so giving a really individualized approach for every patient.

There are new drugs coming on the horizon. Fortunately or not fortunately, this disease does also affect a large adult population. And so, as drugs are developed for that population, we're able to pull them over to pediatrics. And there are some new drugs that are exciting in clinical trials with adults, and I expect to see them used in children within the next couple of years, a whole new classes of medicines.

But the other thing is one of the primary things in pulmonary hypertension is heart failure. And for example, here at Children's Medical Center, we have a large and active heart failure and mechanical support team that hasn't ever made it over to pulmonary hypertension treatment. But I would imagine in the future, we'll be able to support our patients better that way and give them more longevity until we can get them to what would hopefully be a cure.

Nicolas Madsen, MD: Excellent. Megan, you have a tremendously successful academic background. Can you talk a little bit about questions that you are particularly interested in and where you are hoping to take your research?

Megan Griffiths, MD: Yeah. So, I have been doing research in proteomics of pulmonary hypertension, proteomics meaning protein, study of the proteins in the blood. And it falls into that precision medicine category. And my group is trying to understand the particular protein profiles of patients with different types and different severities of pulmonary hypertension, so that we can try and non-invasively understand that patient's disease.

Right now, the standard is, when I'm learning about a patient with pulmonary hypertension, I take them to the cath lab. if they're old enough, I try and do pulmonary function testing and stress testing, we do genetic testing. But we're really trying to see, can we understand on a microscopic protein and metabolite level how a patient's heart and lungs are functioning? And then, based on that, can we target treatments? And then even more, because obviously your heart and lung function on one day may be different three months from now, can we target treatment over time and really, really closely monitor how a patient is doing with minimal intervention, with minimal having to come back to the hospital for caths and stress tests and echoes. And all these other labor intensive things. So, so far, we've got a panel of some proteins and they're looking quite exciting.

Nicolas Madsen, MD: That's terrific. We are enormously privileged and grateful, privileged to support you and your efforts and grateful to you for applying this expertise to this vulnerable patient population.

Before we sign off, I guess one thing that may be helpful for the audience to hear a little bit about is you've mentioned some uniquely vulnerable patient populations who oftentimes travel from far distances to come to Children's for this particular type of care and whose care is quite long-lasting and chronic in nature. Tell me a little bit about the team necessary to do this. I assume that this is not something that you necessarily juggle all on your own. What does that team look like and how do you imagine that team growing and expanding over the near term?

Megan Griffiths, MD: Yeah, you're absolutely right. I can't juggle this all on my own. And for children with this disease and for families really, I think it's essential to have a lot of support once they leave the hospital, both in the hospital, but especially once they leave the hospital. So, our patients on medicines, especially IV or inhaled medicines, we have somebody on call for them 24 hours a day, seven days a week. You just pick up the phone, call us, somebody will answer.

We have social work support. We have a pharmacist. I'm very privileged to be part of the pediatric advanced cardiac care team, where really our approach is multidisciplinary, where we're looking at physician, advanced practitioner or nurse practitioner, nurses with experience in this, social workers, we have dieticians, a pharmacist who's just dedicated to us. So, we really are bringing in expertise from many different places.

And then, I also work closely with my pulmonology colleagues and my other cardiology colleagues. And our goal is to try and meet the family where they are. So if you live hours away from here and you have your cardiologist that you've been going to for 10 years, we want you to continue to go and see that cardiologist and we'll work with them, and then you just come and see us periodically. We also work closely with the specialty pharmacies to make sure that our patients are getting all of their medications delivered to them timely, never running out, making sure that all the insurance stuff is taken care of. So, we really want to partner with the families and make sure that they feel like they have somebody there available to them supporting them through this, because it can be a difficult disease to navigate.

Nicolas Madsen, MD: Well, Megan, really appreciate your time today. Appreciate your willingness to chat about a subject matter that I know you are so passionate about and the patient population you care so deeply for. We are very grateful that you are member of the Heart Center team. And we really look forward to supporting you and really principally supporting our patients in the years to come. I leave it to you for any last words.

Megan Griffiths, MD: I just really am so glad that I got the privilege of coming out here, really enjoying being in Dallas, and I look forward to being able to provide this for the children and for the families of North Texas.

Nicolas Madsen, MD: Outstanding. Thanks Megan.

Megan Griffiths, MD: Thank you, Nicolas.

Nicolas Madsen, MD: Thanks again for tuning in. It was a real pleasure to have Dr. Megan Griffiths with us today, as we learned a little bit more about pulmonary hypertension and, in particular, this patient population which is certainly growing. And thankfully, our ability to help them is growing right alongside them. Thanks to the audience for listening in. Please don't hesitate to reach out to us at the Heart Center at Children's Health in UT Southwestern anytime. We look forward to your questions and I certainly look forward to the next time I have an opportunity to speak with a member of our team. Thanks very much.