Cardiac function at follow-up in infants treated with therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy

Abstract

Compromised myocardial function and persistent elevated pulmonary vascular resistance are common among neonates treated with therapeutic hypothermia (TH) for hypoxic-ischemic encephalopathy (HIE). There is a lack of data regarding persistence of cardiac alterations after discharge from the neonatal intensive care unit (NICU). We assessed cardiovascular profiles after NICU discharge. Echocardiogram data, including speckle-tracking echocardiography (STE), were extracted from the latest outpatient scan. Data were compared by initial amplitude-integrated encephalography (aEEG) profiles on admission [normal vs. abnormal]. In total, 70 (19%) neonates had a follow-up echocardiogram (22 with initial normal aEEG, 48 with abnormal aEEG). Age at follow-up was similar between the two groups (6.2 vs. 7.7 months, [p = 0.08]). Neonates with an initially abnormal aEEG showed more negative Right Ventricle (RV)-peak global longitudinal strain (−28.2 vs. −26.0%, [p = 0.02]), RV-peak free wall longitudinal strain rate (−1.24 vs. −1.10 [1/second], [p = 0.01]), and RV-peak free wall longitudinal strain rate (−1.50 vs. −1.27 [1/second], [p = 0.001]). These associations remained after multilinear regression analysis, indicating persistent enhanced RV contraction in the abnormal aEEG group. Neonates with initial abnormal aEEG profiles exhibited increased RV contraction after NICU discharge. Future studies should explore long-term cardiovascular follow-up of neonates with HIE, beyond the perinatal period.