Jul 24, 2018
Dunbar Ivy, MD gives an update on the 6th World Symposium on Pulmonary Hypertension, which was held in Nice, France earlier this year. Dr. Ivy discusses the progress of pulmonary hypertension science and its anticipated future developments. The WSPH series takes place once every five years.
Hi, this is Dunbar Ivy, I'm chief of pediatric cardiology at the University of Colorado School of Medicine and Director of the Pediatric Pulmonary Hypertension Program at Children's Hospital of Colorado.
The World Symposium is a meeting of experts every five years to look at what's happened in the last five years and come up with proceedings that will help guide the clinicians and future directions for research.
The working groups each contribute to different areas, so there's a working group on definition and classification, and then on patients with lung disease or heart disease and what should we use for risk factors in adults, and based on the new therapies that have come out, how should we use them and what's a potential algorithm for treatment. The new thing for us in the last two World Symposiums have been the inclusion of a pediatric working group, which I think is long overdue. We know that children are different than adults and in particularly in how they present with pulmonary hypertension, but also in the causes of pulmonary hypertension. One important example is the developmental aspect.
There are probably genes that are contributing developmentally to pulmonary hypertension and if you look at the classifications, most of the forms of pulmonary hypertension in children are there, but there are many that are not. And so our goal at the World Symposium, one of them was to try to incorporate these developmental lung disease or perinatal causes. We know that in many children that their pulmonary hypertension may start in the womb and then continues immediately after birth, and then for some of them, lifelong. And one of the findings was a gene called T-box 4 or TBX4, which we think is very important in lung development. And we are finding this more in children with pulmonary hypertension.
I believe there were 13 task forces. And so I tried to go to all of them, because you learn from each adult area and try to see how you can apply that to children. For the first time this year was a session on the patient perspective and there was a lady who lost her daughter, unfortunately, to idiopathic pulmonary hypertension from South Africa. But her talk was just amazing in terms of what they went through and the need for worldwide advocacy and awareness campaigns.
We have not been as successful as we want to be in disease recognition. I think one of the keys to better treatment is earlier diagnosis and I think by just getting the word out on how this disease presents and it can be challenging to diagnose. Still, unfortunately, there's a delay of one to two years for many children and adults in diagnosis. So then the patient has more significant disease and it's harder to treat.
The other thing is that by using media, whether that's television or social media. More people have access to the internet. So in the case of South Africa, they had a campaign, which really raised awareness of pulmonary hypertension and raised a lot of money and recognition that some therapies that should be available in many countries are not. And so that's a challenge. I think using media is very important. There have been attempts to train the physicians more to recognize pulmonary hypertension and that has been successful but not nearly as much as direct interaction with parents, families and patients.
Some of the big changes in the last five years have been the development of guidelines for pulmonary hypertension in children in general, but also for patients with bronchopulmonary dysplasia (BPD). So we, as a field, are seeing more and more kids who are born prematurely who develop pulmonary hypertension. They're living longer and they have pulmonary hypertension and needed guidelines for treatment. And so this is a first step to teach people how to manage these patients in a stepwise fashion.
There was some controversy with regards to the change in the definition of pulmonary hypertension and the lowering of the catheterization derived mean pulmonary pressure from 25 to 20, which is good, but also challenging. Good because I think there are certain small subgroups of patients who have real pulmonary hypertension that's going to progress and that may allow earlier treatment. But on the opposite side of the coin, is that there may be many more people who are treated who may not need therapy, who have a very mild form that's associated with left heart disease, and these medications have not been shown to be beneficial in adults with left heart disease.
I would like to see better designs for approval of drugs in children between Europe and the Americas. I would like to see that there's an accepted endpoint. That we can work together as an international community to understand how drugs are used in children, how to use them, what doses should we be using, and then to get them labeled and approved because we're seeing more and more, because of the cost of medications, that it can be very challenging to get these drugs for people who really need it. So that would be one thing, would be a better regulatory environment, if you will, where we would work as an international community to develop end points and trial design.
I think the other would be continued guidelines on treatment of certain diseases. When should we use combination therapy in children, I think is a very important area. And then the other thing is how to use the registries that we've developed. There are about 3000 pediatric patients in registries and how do we use that data to define which drugs are working better, which combinations of drugs, what kind of patients should we be targeting? So, for example, in the Pediatric Pulmonary Hypertension Network [PPHNet], almost half of the patients have some form of chronic lung disease and particularly bronchopulmonary dysplasia and congenital diaphragmatic hernia. So that is three to four fold times what some of the other registries have shown. And so that just says that we need to a look at that population better and continue to look at treatment for them.
My name is Dr. Dunbar Ivy, and I'm aware that I'm rare.
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