Impact of Pulmonary Vein Stenosis and Congenital Heart Disease on Mortality in Premature Infants with Bronchopulmonary Dysplasia and Pulmonary Hypertension
Background: Pulmonary hypertension (PH) is increasingly recognized in premature infants with bronchopulmonary dysplasia. Management of PH is more difficult in the presence of pulmonary vein stenosis (PVS) and significant congenital heart disease (CHD).
Objectives: To describe the characteristics of premature infants with BPD and PH who underwent cardiac catheterization and evaluate the effect of PVS and CHD on mortality at follow-up.
Methods: This was a single-centered retrospective study to describe premature infants born at 1.5) and structural heart diseases requiring transcatheter and/or surgical interventions. To evaluate the effect of PVS and CHD on the survival, the Kaplan-Meier survival method with a log-rank test and Cox proportional hazards regression was used.
Results: The 53 infants that met inclusion criteria were born prematurely at mean gestational age of 26 ± 3 weeks with a birth weight of 782 ± 346 gm. Cardiac catheterization was performed at mean age of 11 months. The study cohort was divided into CHD (n=13), PVS (n=8) and non-CHD (n=32) groups based on the catheterization findings. In the CHD group, simple lesions (atrial and/or ventricular septal defect 4, and patent ductus arteriosus 7) were treated in 10 patients. In contrast, 2 with complex CHD lesions (truncus arteriosus and tricuspid atresia ) were left untreated due to significant pulmonary vascular disease. In the PVS group, PVS was not detected by pre-procedural echocardiography and was discovered by cardiac catheterization in 4/8 (50%) patients. Three patients with PVS received surgical (n=1) and transcatheter (n=2) interventions and remain alive. In the non-CHD group, all were treated with oral pulmonary vasodilators and 3 died (9%). At a median follow-up age of 3.6 years (range 5 months – 17.7 years), overall mortality rate was 19% (10/53). The PVS group had a highest mortality rate at 63% with a hazard ratio of 8.7 (95% confidence interval: 2.5 to 30.9, p=0.001) compared to the others.
Conclusions: Pulmonary vein stenosis occurred in 15% of premature infants with BPD and PH. Severe pulmonary vascular disease associated with CHD and/or PVS carried a poor prognosis. Screening for PVS should be emphasized in premature infants with BPD and PH.