147 - Therapeutic Hypothermia Treatment for Hypoxic Ischemic Encephalopathy in Infants with Congenital Heart Disease

Poster Number: 147
Publication Number: 147.135

Devon Swofford, Washington University in St. Louis School of Medicine, St. Louis, MO, United States; Paige Rawitscher, The College Of William and Mary, Clayton, MO, United States; Cynthia Ortinau, Washington University in St. Louis School of Medicine, St. Louis, MO, United States; Avihu Z. Gazit, Washington University in St. Louis School of Medicine, St Louis, MO, United States; Zachary A. Vesoulis, Washington University School of Medicine, St. Louis, MO, United States

Background: Hypoxic Ischemic Encephalopathy (HIE) and congenital heart disease (CHD) are two common conditions that increase the risk of neonatal brain injury and neurodevelopmental impairment. A subset of neonates is diagnosed with HIE and CHD. While there are treatment strategies for HIE and CHD separately, there is conflict on the course of treatment when both conditions occur together.

Objective: This study aims to identify characteristics of infants with CHD and HIE, and the differences between infants who were treated with therapeutic hypothermia (TH) and those who were not.

Design/Methods: Newborn infants admitted to the CICU or NICU of St. Louis Children’s Hospital between 2011 and 2021 were screened for inclusion. Inclusion criteria: neonates born at ≥35 weeks gestational age and diagnosed with HIE and CHD between 1/1/11 and 12/31/20 (Table 2). Exclusion criteria: congenital anomalies other than CHD, non-CHD surgical problems, or genetic conditions (other than Trisomy 21). Chart review was conducted to collect: maternal factors (pre-eclampsia, gestational diabetes), sentinel events (cord trauma, uterine rupture, placental abruption), and neonatal factors (Apgar scores, birth weight, TH treatment, seizures, hepatic dysfunction, renal failure, PPHN diagnosis, and mortality). Analysis done with Mann Whitney U test or Fisher’s Exact Test.

Results: 31 neonates met inclusion criteria. 22 underwent TH and 9 did not. CHD infants who received TH treatment were similar to those who did not undergo TH with the exception of mortality and PPHN diagnosis. Mortality was significantly lower for infants who received TH (14% vs. 44% p< 0.01). PPHN was significantly more common in infants who received TH (23% vs. 0%, p< 0.01). 15 patients had seizures; this was not statistically different between TH and no TH groups. Gestational diabetes, pre-eclampsia, gestational age, birthweight, Apgar score at 1 and 5 minutes, sentinel events, cord pH, renal and hepatic failure were not significant between groups.

Conclusion(s): CHD infants who undergo therapeutic hypothermia treatment for HIE have a lower mortality rate, but higher incidence of pulmonary hypertension compared to CHD infants who do not undergo TH. Patients with CHD and HIE who undergo TH treatment have a mortality rate which is comparable to HIE infants without CHD who undergo TH (14% vs 10-20%). CHD infants who do not undergo TH treatment have a significantly higher mortality rate (44%), despite having similar perinatal characteristics. Although this is a small data set, TH treatment appears to be beneficial and should be considered for all infants with CHD and HIE.