Dr. Dunbar Ivy - phaware® interview 480

Dr. Dunbar Ivy, a pediatric cardiologist, discusses the value of repeat heart catheterization in patients with pulmonary hypertension. He highlights a recent study that compared the findings of the first and second heart catheterizations. The study showed that while the first heart catheterization is important for diagnosis and choosing the best therapies, it is not the best predictor of long-term outcomes. Dr. Ivy emphasizes that the decision to perform a second heart catheterization should be individualized and discussed with the patient's pulmonary hypertension physician. He also mentions that cardiac MRI is becoming more valuable in assessing right heart function and can be used as an alternative to heart catheterization in certain cases. 

Hi, I’m Dunbar Ivy. I am a pediatric cardiologist at the University of Colorado in Denver, Colorado. I’ve had an interest in pulmonary hypertension for very close to 30 years. For me, it’s been a very exciting journey to see things move from really no therapies to one therapy to over 12 therapies. That’s really been exciting to be able to use some of those medicines off label, but I think they really have helped children and improved survival.

Today, I’m at the UCSF pediatric and neonatal pulmonary hypertension meetings and one of the topics for discussion is the value of repeat heart catheterization. There was a recent paper from the group in Paris at Necker Hospital for Sick Children. They looked at patients who had repeat cardiac catheterizations. They compared what they learned from the first heart cath to what they learned at the second heart cath. 

This is an important question for clinicians. It’s an important question, particularly for families, because I think heart catheterization is very much a stress point for families and they really want to know is this crucial or not?

What the paper showed is that the first heart catheterization is really standard to be sure we know what we’re treating and can choose the best therapies. Also, so we don’t miss diagnoses that sometimes can be hard to tell by other modalities. That is really important. A few things that were very interesting was that the first heart catheterization is not the best at predicting how you’re going to do. It gives you an idea. What the group there looked at was what did the second heart catheterization tell you? The predictors of how patients would do, children, over the following years were different between the first heart catheterization and the second. There were some similarities, but some that were not so similar.

So, it points out that we need to think about performing the second heart catheterization, but there is value in it. I think it’s really an individual discussion with your pulmonary hypertension physician. But I think there is information that can be very valuable to help manage the patients after the second heart catheterization.

For us at our center, it’s a very patient-dependent and an individual decision on whether we consider a second heart catheterization. A patient that may have, for example, bronchopulmonary dysplasia or chronic lung disease, we don’t tend to repeat those heart catheterizations if the patients are doing well. The patients who have idiopathic or heritable pulmonary hypertension, we feel stronger that a repeat catheterization within the first year is helpful to be sure that we’re treating them appropriately. Reason being, is that patient with idiopathic pulmonary arterial hypertension may have a progressive disease, whereas the patient with bronchopulmonary dysplasia tends to get better over time. So, those are very broad generalities. We tell the patient if they have idiopathic disease that they should expect to have a repeat catheterization within the first year.

With regards to can we replace cardiac catheterization with cardiac MRI, we use cardiac MRI more and more. I think it’s extremely valuable, because the patients in general are not sedated. They’re in their natural state, just laying on the table. It gives us great information about right heart function, right heart size, right heart thickness and overall heart output. So, it’s very valuable. Those are very important clinical measures that we use to determine should we increase therapy, should we stay where we are, maybe should we decrease therapy. So ,our decision about whether we do a heart catheterization next or a cardiac MRI is individualized. But if it’s a patient who’s doing well and had, for us, idiopathic PAH and they had their repeat catheterization and they’re doing well, then we’ll follow them by cardiac MRI. We don’t feel that cardiac catheterization is the only way to follow patients.

With regards to adults, I think they tend to do more heart catheterizations than we do in children, and that’s because it’s safer, and in most adults with minimal or sometimes no sedation, you can get the information very safely and very quickly. Whereas in children, many of them will need sedation or sometimes general anesthesia. I think they tend to repeat the catheterization more than we do. I think the use of cardiac MRI varies amongst adult centers. I think some use it more than others. 

One of the advantages of cardiac MRI is really a very accurate evaluation of right heart function, right heart size, right heart thickness and overall output. Those are major predictors of outcome and how the patient is doing and will do. 

It’s very important to work with your team and to determine the best protocol for your child. This may vary depending on your personal feelings; also the opinions of your pulmonary hypertension program. Some may be more invested in heart catheterization and some may be in cardiac MRI and some in other exercise kind of parameters to follow patients. I think the main key is regular evaluation and follow-up so that these subtle changes can be picked up early and then change treatment if needed.

I’m Dunbar Ivy. I’m aware that my patients are rare.

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