In these case studies, Dr. Griffiths shares how specialized treatment helps manage complex pulmonary hypertension in children.
Pulmonary hypertension (PH), or high blood pressure in the lungs, is exceedingly difficult to manage because it is often a multifactorial disease that involves the heart and lungs.
“A key part of our approach is understanding how pulmonary hypertension manifests in each patient. Then we determine the best targeted medications for that individual,” says Megan Griffiths, M.D., Pediatric Cardiologist at Children’s Medical Center Dallas, part of Children’s Health℠, and Assistant Professor at UT Southwestern.
In September 2022, Dr. Griffiths launched the Pulmonary Hypertension Program within The Heart Center at Children’s Health. She was excited to meet a growing need to provide advanced therapy for children in North Texas with pulmonary hypertension. Dr. Griffiths and her team now offer the full range of PH medications, many of which require specialized training because of their potency and potential side effects.
The case studies below illustrate how the pulmonary hypertension team successfully navigated the diagnosis and treatment of patients who once couldn’t breathe on their own -- and who now have a good long-term prognosis.
Case study #1: Managing potent medication in a child with severe heart disease
A 4-year-old girl in the Children’s Health ICU needed high levels of oxygen. Born with a single ventricle, she had received several surgeries to repair the left side of her heart and restore the flow of blood from her lungs to her body. But her last surgery was not successful. “This child was struggling and out of options,” Dr. Griffiths says.
The team suspected PH, something many patients with a single ventricle develop. But diagnosing PH and determining its severity required a cardiac catheterization under anesthesia. “It was a risk because the girl was so sick,” Dr. Griffiths says. “Thankfully, our anesthesia and catheterization teams frequently perform similar procedures on medically fragile patients and are experts in conducting them safely.”
The catheterization revealed severe PH. “I knew right away that the girl needed IV Remodulin, which is the strongest tool in my toolbox,” Dr. Griffiths says. She worked with the program’s dedicated pharmacist and started the patient on the medication.
Managing Remodulin for a patient with both severe PH and heart disease is challenging. As the medication reduces blood pressure in the lungs, it increases blood flow to the left side of the heart, forcing it to pump more blood and work harder. Because of her training in PH therapy, Dr. Griffiths had the expertise to slowly increase the dose while monitoring the patient to ensure the left side of the heart was able to adapt.
The girl made a “magical turnaround,” Dr. Griffiths says. Within a few weeks, she went from needing 50 liters of oxygen per minute to only two liters and was able to get out of bed and eat.
She made it home for Christmas with a pump providing continuous Remodulin. After one year, Dr. Griffiths successfully switched her to an oral version, which is easier to manage and less potent. The patient will need a heart transplant because of issues related to having a single ventricle. And now she is healthy enough to receive one.
Case study #2: Balancing disease complexity in a premature baby
A baby born at 22 weeks gestation had a form of PH caused by underdeveloped lungs. She did not respond to the first-line treatment, inhaled nitric oxide.
“She had to be sedated and couldn’t get off the ventilator,” Dr. Griffiths says. “The NICU team did a phenomenal job keeping her alive, but she wasn’t progressing.”
Cardiac catheterization showed that the baby had PH that involved both sides of her heart. The right side of her heart was failing and couldn’t get blood into the lungs, and the left side was very stiff and couldn’t get blood from the lungs.
“It is an under-recognized problem that premature babies with PH can also have an underdeveloped heart that is not able to pump blood in and out of the lungs,” Dr. Griffiths said.
Working with her colleagues in the Children’s Health pediatric heart failure team, Dr. Griffiths started the baby on heart failure medications to restore cardiac function. Then she slowly added back in Sildenafil and other PH meds.
The baby, now age 1, is getting ready to go home from the hospital at last. The team expects that the child will be able to stop taking meds in about two years if her lungs continue to grow well.
Why Children’s Health: Speeding cutting-edge PH treatments to patients
Pulmonary hypertension is extremely rare and very challenging to treat. Dr. Griffiths is working with colleagues at other leading PH care centers in the U.S. so they can learn from each other’s experiences. They have recently been discussing the best timing for switching children who have PH and single ventricle disease, like Dr. Griffiths’ patient, from IV to oral Remodulin.
Other discussions focused on the recently approved drug, called Winrevair, that may be the first to cure some forms of the disease, rather than just managing them. Although Winrevair is only approved for use in adults, Dr. Griffiths notes that many adult PH medications are successfully used off-label in children. Children’s Health will initially use Winrevair in children whose prognoses are dismal, but as their pediatric experience grows, they will be able to offer it more widely. They have already planned how to administer and monitor the treatment.
“It is an exciting time in the field,” Dr. Griffiths says. “Expertise in developing plans and managing treatment is becoming more critical as the formulary of PH medications grows. And we’re ready for it.”
