Hemodynamic phenotypes in congenital diaphragmatic hernia and their association with morbidity and mortality

Congenital diaphragmatic hernia (CDH) is a severe condition associated with high morbidity and mortality. Its severity correlates with the degree of pulmonary hypoplasia. Recent literature has emphasized the importance of identifying distinct hemodynamic phenotypes (HP) to guide physiology-based management.

We included all CDH patients evaluated by targeted neonatal echocardiography from January 2017 to April 2022. HPs were classified into three groups: HP1 (mild pulmonary hypertension [PH] without ventricular dysfunction), HP2 (pre-capillary PH), and HP3 (post-capillary PH). We compared differences between survivors and non-survivors using the Mann-Whitney U-test, analyzed baseline and pre/post-surgical echocardiographic parameters using the Wilcoxon test, estimated survival curves using Kaplan-Meier analysis, and compared length of stay using the Kruskal-Wallis test.

Among 28 included neonates, 24 survived (86%). HP distribution was: HP1 9 patients (32%), HP2 8 patients (29%), and HP3 11 patients (39%). Four patients died, two post-surgery and two without surgical intervention. Mortality-associated factors included higher pCO₂, lower left ventricular (LV) output, decreased LV compliance, and elevated pulmonary vascular resistance (PVR). Survival analysis revealed a non-significant trend toward higher mortality in HP2 (one death) and HP3 (three deaths). Follow-up demonstrated progressive increases in biventricular output, PVR reduction, and compensatory cerebral vasodilation.

HP correlated with patient mortality, particularly in cases with greater pulmonary hypoplasia (higher CO₂) and compromised ventricular performance. Echocardiographic monitoring revealed improvements in biventricular performance, decreased PVR facilitating surgical intervention, and cerebral perfusion adaptation.