Children with IPH Have Similar Transplant Survival Rates as Those with Other Indications, Study Says

Children with idiopathic pulmonary hypertension (IPH) who underwent lung or combined heart-lung transplants show similar survival rates to children who underwent these procedures for other indications, according to a study.

Data also indicated that children who had a transplant at an older age had better outcomes.

The study, “Transplant outcomes for idiopathic pulmonary hypertension in children,” was published in The Journal of Heart and Lung Transplantation.

IPH is an indication for lung transplant or combined heart‒lung transplant in children. Prior studies of lung transplant outcomes in pediatric populations have analyzed a small number of cases, which limits the accuracy of the data.

A team at Nationwide Children’s Hospital in Ohio used the United Network for Organ Sharing (UNOS) registry to evaluate outcomes in children with IPH undergoing lung or combined heart-lung transplant, and to assess clinical characteristics that could be associated with post-transplant survival.

In total, 65 children (26 boys, 39 girls, mean age of 10 years) were included in the study. They had transplants between May 2005 and December 2015, with follow-up data collected through December 2016. Forty-seven patients underwent a double lung transplant, and 18 underwent heart and lung transplant.

Analyzed clinical data included patients’ age, lung allocation score (LAS; used to prioritize waiting list candidates by estimating the severity of illness and chance of post-transplant survival), Status 1A designation for heart‒lung transplant (which refers to patients with the highest priority based on medical urgency), and mean pulmonary artery pressure (mPAP).

Results showed a total of 28 deaths, 19 in the group undergoing lung transplants and nine in children having a combined heart-lung transplant. Five-year survival rates were 61% for lung and 48% for combined heart-lung transplants, although this difference was not statistically significant. In addition, overall survival in the two groups was not different from that of children undergoing the same procedures for other indications.

Researchers also observed that older age at the time of the transplant correlated with a lower risk of death. In contrast, LAS in patients older than 12 years, Status 1A in patients undergoing combined transplant, and mPAP before the procedure did not significantly influence survival.

Fifty-four additional children were listed for but did not receive a transplant; of these, 22 (40.7%) died, 14 experienced clinical improvement and no longer required a transplant, three refused to have the procedure, and four were too sick.

These non-transplanted patients had lower mPAP (63 mmHg vs. 77 mmHg), and had Status 1A less frequently (4% vs. 20%) than children who went through with the procedure.

These results confirmed data from The International Society for Heart and Lung Transplantation Registry, showing that “post-transplant outcomes for IPH appear to be similar to children transplanted for other indications,” the researchers wrote.

“In conclusion, the very small number of children transplanted for a primary indication of IPH (65 over a 10-year period) suggests that transplant may be an underutilized treatment modality in this population, and should strongly be considered for appropriate pediatric candidates, especially older children,” they said.

Results also suggest that measures of disease severity, such as mPAP and LAS, “may not accurately reflect chances of long-term survival in this patient population,” according to the team.