Research has shown that pulmonary hypertension is associated with substantial morbidity and mortality in children. Registry data from the United Kingdom and the Netherlands estimate an incidence of idiopathic pulmonary hypertension of 0.48 to 0.70 cases per million, respectively. However, such data on pediatric pulmonary hypertension remain unknown in the United States. Studies assessing the inpatient care of pediatric pulmonary hypertension in the U.S. have been small or focused on select subgroups of patients.

Reviewing the Data

To determine trends in volume, demographics, procedures performed during admission, and resource use, Bryan Maxwell, MD, MPH, Melanie Nies, MD, and colleagues examined national data on hospitalizations among pediatric patients with pulmonary hypertension. The study, published in Pediatrics, reviewed data from 1997 to 2012 in the Kids’ Inpatient Database, the largest publicly available database of inpatient pediatric care in the United States, according to Dr. Nies. Beginning in 1997, the database has released discharge data every 3 years from thousands of hospitals throughout the U.S.

Overall, children with pulmonary hypertension accounted for 0.13% of 43 million pediatric hospitalizations included in the registry during the study period. Discharges for pediatric pulmonary hypertension doubled from 1997 to 2012. Cumulative, inflation-adjusted national hospital charges associated with pediatric pulmonary hypertension hospitalizations increased from $926 million in 1997 to $3.12 billion in 2012. “It is important to note that although all-cause, in-hospital mortality associated with the condition remains high, it decreased from 11.3% of hospitalizations in 1997 to 5.9% in 2012,” Dr. Nies says.

The study investigators also found a shift in the type of children who accounted for the majority of pediatric pulmonary hypertension cases. “Children with congenital heart disease have historically been associated with the majority of pediatric pulmonary hypertension cases,” says Dr. Nies. “However, we showed that children without congenital heart disease accounted for an increasing number of pediatric pulmonary hypertension-associated hospitalizations.” In 2012, children without congenital heart disease actually accounted for the majority of pulmonary hypertension-related hospitalizations (56.4%).

Important Implications

Dr. Nies notes that the exact reasons for the study team’s findings are not completely clear. “Our findings may reflect improved recognition of pulmonary hypertension over time and broader inclusion of patients with the condition,” she says. “It could also be the result of improvements in medication that have enabled more children to survive longer than was possible 15 to 20 years ago.”

Surprisingly, the study found that only about one-third of pediatric pulmonary hypertension-related hospitalizations were at children’s hospitals. This occurred despite such centers often being best suited to care for this patient population, and may have implications for the persistently high in-hospital mortality rate.

“Clinicians have suspected for some time that there’s a growing population of children being hospitalized for pulmonary hypertension,” says Dr. Nies. “Our findings confirm these suspicions and can help us appropriately allocate resources in order to optimize care of this patient population. A national registry to track patient outcomes over time may help provide a foundation for future studies to test novel therapies.”