Clinical fellow Asan Medical Center Children's Hospital Seoul, Seoul-t'ukpyolsi, Republic of Korea
Background: Pulmonary hypertension (PH) is a major contributor to the mortality and morbidity of infants with congenital diaphragmatic hernia (CDH). Objective: This study aims to evaluate long-term course of PH and both early and long-term cardiopulmonary outcomes and assess prognostic markers for long-term outcomes of PH in CDH infants. Design/Methods: A single-center, retrospective cohort study conducted from the neonatal intensive care unit (NICU) at Asan Medical Center over a decade (2013-2022). Inclusion criteria included survivors with isolated Bochdalaek diaphragmatic hernia and a gestational age of ≥ 35 weeks, with available observed-to-expected lung-to-head ratio (O/E LHR) measurements in fetal ultrasound. PH assessments via echocardiograms were performed at the following intervals: P0 (within 48 hours of birth), P1 (between 48 hours and 2 weeks), P2 (between 2 weeks and 3 months of age), P3 (between 6 months and 1 year of age), and P4 (between 2 and 6 years of age). Right ventricular systolic pressure (RVSP) was calculated using Bernoulli’s equation in the presence of tricuspid regurgitation. PH was defined as an estimated pulmonary arterial pressure ≥ 2/3 systemic blood pressure. The severity of PH was assessed hierarchically based on ductus arteriosus level shunt, interventricular septal position, and tricuspid regurgitant jet velocity. Results: Among 124 infants, mean gestational age was 38 ± 1 weeks, and mean birth weight was 3013 ± 452 g. Mean O/E LHR was 57.0 ± 17.6 %, with 16 (12.9%) infants necessitating extracorporeal membrane oxygenation (ECMO). The incidence of PH has decreased overtime with rates of 76% (P0), 66% (P1), 13% (P2), 6% (P3), and 3% (P4) among the survivors. PH remained unresolved at the time of discharge in 6 (4.8%). Those with persistent PH showed a higher incidence of ECMO (P < 0.001), inhaled nitric oxide (P=0.005), and patch repair (P=0.003). Within the subgroup of CDH infants for whom RVSP documented at P0 (n=67), a negative correlation between RVsp and prenatal O/E LHR was observed (r=-0.335, P=0.005). There was no significant correlation between O/E LHR and RVSP from P1 to P4.
Conclusion(s): In majority of survivors with isolated CDH, resolution of PH occurred after 2 weeks of age. The O/E LHR correlated with RVSP during the early days of life, but this correlation was not present in measurement taken thereafter.
