047 - Characteristics and Outcomes of Extremely Low Gestational Age Neonates with Early Pulmonary Hypertension

Publication Number: 47.4234

Rachel Mullaly, The Rotunda Hospital, Dublin, Dublin, Ireland; Aisling M. Smith, The Rotunda Hospital, Dublin, Dublin, Ireland; Claire Murphy, Chelsea and Westminster Hospital, London, England, United Kingdom; Sean Armstrong, Rotunda Hospital, Lusk, Dublin, Ireland; Orla M. Franklin, Trinity College Dublin, Dublin, Dublin, Ireland; Naomi McCallion, Royal College of Surgeons in Ireland, Dubin, Dublin, Ireland; Afif EL-Khuffash, Royal college of surgeons in Ireland, Dublin, Dublin, Ireland

Background: There is limited evidence on the effect that early pulmonary hypertension (PH) has on outcomes in extremely low gestational age neonates (ELGANs) and even less relating to the use of advanced echocardiographic techniques in this setting.

Objective: To assess the incidence and outcomes, and to analyse the initial and final echocardiographic parameters in ELGANs with initial PH versus controls.

Design/Methods: Infants born < 28 weeks gestation between July 2020 and March 2024 were considered for inclusion. Echocardiographic assessments were carried out at multiple timepoints. Initial assessment scan was performed at 24 – 48 hours and early PH was diagnosed if there was a bidirectional shunt present. A repeat echocardiogram was performed at 36 weeks corrected gestational age (CGA). SPSS version 25 was used to conduct the analyses.

Results: 166 infants were considered for inclusion. Initial PH was detected in 20 (12%) infants. 146 infants did not have initial PH and were considered controls. Clinical characteristics are shown in Table 1. Functional echocardiographic measurements on initial and 36 week CGA echocardiograms are shown in Tables 2 and 3, respectively. Infants with initial PH had a higher rate of death before discharge than controls (11 (55%) vs 16 (11%)) (p < 0.01). They were also more likely to develop severe intraventricular haemorrhage (7 (35%) vs 15 (10%)) (p < 0.01) and were more likely to require inotropic support (15 (75%) vs 36 (25%)) (p < 0.01). Infants with initial PH had an 8.8-fold increased risk of death compared to controls (8.8 (2.2 – 35.3) (OR (95% CI)) (p < 0.01).

Conclusion(s): Early echocardiographic screening successfully identified a subgroup of ELGANs who had initial PH. Shorter systolic time, longer IVRT and a trend towards longer IVCT in the PH group on initial echo suggests that there is altered cardiac function secondary to PH. Although LV and RV systolic and diastolic function, as measured by ejection fraction, TDI and global longitudinal strain did not differ significantly between groups, the reduced twist and torsion apparent in the PH group suggests subtle impairments in myocardial function. The significant difference in echocardiographic parameters at 36 weeks CGA between groups, particularly in left ventricular rotational mechanics, suggests that subclinical cardiac dysfunction persists in these infants following resolution of PH. This may have long-term cardiorespiratory implications that remain yet unknown.

Table 1 Clinical characteristics of infants with initial pulmonary hypertension
Values are presented as means ± standard deviation, median [interquartile range], or count (percentage (%)).
CPR: cardiopulmonary resuscitation; MgSO4: magnesium sulphate; PPROM: preterm prelabour rupture of membranes

Table 2 Functional echocardiographic measurements on first echocardiogram
Values are presented as means ± standard deviation or median [interquartile range].
LV: left ventricle; RV: right ventricle; TAPSE: tricuspid annular plane systolic excursion


Table 3 Functional echocardiographic measurements on echocardiogram at 36 weeks corrected gestational age
Values are presented as means ± standard deviation or median [interquartile range].
PAAT: pulmonary artery acceleration time; RVET: right ventricular ejection time; LV EI: left ventricular eccentricity index; TAPSE: tricuspid annular plane systolic excursion