Survival analysis of infants with bronchopulmonary dysplasia-associated pulmonary hypertension: a single-center study in China

To describe the outcome and identify the risk factors associated with death in very premature infants with bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH). A single-center retrospective study was conducted in infants with a gestational age <32 weeks and/or birth weight <1500 g who developed BPD associated PH (BPD-PH) at Children's Hospital of Zhejiang University School of Medicine between January 2011 and December 2023. Kaplan-Meier's estimate and Cox regression were performed for survival analysis. Eighty-three infants had BPD-PH beyond 36 weeks' postmenstrual age (PMA), with 37 (44.6%) died during the hospitalization or follow-up. The overall survival rates at 2, 6 months and 1 year after diagnosis of PH were 85.5%, 66.3%, and 57.5%, respectively. Univariate Cox regression analyses showed that lower birthweight, invasive mechanical ventilation (IMV) at 36 weeks PMA, supra-systemic PH, longer duration of IMV, right ventricular (RV) dilation, postnatal dexamethasone use, and multiple PH-targeted therapy were significantly associated with a worse survival. However, in the multivariate Cox regression analysis, only supra-systemic PH (HR 3.660, 95%CI 1.586-8.442, p = .002) and RV dilation (HR 2.159, 95%CI 1.061-4.393, p = .034) were associated with a lower survival. Infants with BPD-PH have a high risk of death, especially in the first year after diagnosis of PH. Mortality in those infants was associated with increased severity of PH and RV dilation.