The Impact of Prematurity on Morbidity and Mortality in Newborns with Dextro-transposition of the Great Arteries.

Prematurity is a risk factor for adverse outcomes after arterial switch operation in newborns with D-TGA (D-TGA). In this study, we sought to investigate the impact of prematurity on postnatal and perioperative clinical management, morbidity, and mortality during hospitalization in neonates with simple and complex D-TGA who received arterial switch operation (ASO). Monocentric retrospective analysis of 100 newborns with D-TGA. Thirteen infants (13.0%) were born premature. Preterm infants required significantly more frequent mechanical ventilation in the delivery room (69.2% vs. 34.5%, p = 0.030) and during the preoperative course (76.9% vs. 37.9%, p = 0.014). Need for inotropic support (30.8% vs. 8.0%, p = 0.035) and red blood cell transfusions (46.2% vs. 10.3%, p = 0.004) was likewise increased. Preoperative mortality (23.1% vs 0.0%, p = 0.002) was significantly increased in preterm infants, with necrotizing enterocolitis as cause of death in two of three infants. In contrast, mortality during and after surgery did not differ significantly between the two groups. Cardiopulmonary bypass times were similar in both groups (median 275 vs. 263 min, p = 0.322). After ASO, arterial lactate (34.5 vs. 21.5 mg/dL, p = 0.007), duration of mechanical ventilation (median 175 vs. 106 h, p = 0.038), and venous thrombosis (40.0% vs. 4.7%, p = 0.004) were increased in preterm, as compared to term infants. Gestational age (adjusted unit odds ratio 0.383, 95% confidence interval 0.179-0.821, p = 0.014) was independently associated with mortality. Prematurity is associated with increased perioperative morbidity and increased preoperative mortality in D-TGA patients.

Outcomes in very low birthweight infants with severe congenital heart defect following cardiac surgery within the first year of life.

OBJECTIVES: Very low birthweight (<1500 g, VLBW) infants with severe congenital heart defect (CHD) are at increased risk for perinatal and operative mortality. This study aims to describe morbidity, long-term mortality and neuro-developmental outcome in early childhood in VLBW infants who received cardiac surgery for severe CHD within 1 year after birth. METHODS: Monocentric observational study on VLBW infants with severe CHD born between 2008 and 2017. Neurodevelopmental impairment at 2 years corrected age was defined as cognitive deficit, cerebral palsy or major neurosensory deficit. RESULTS: A total of 24 patients were included. Twenty-one (87.5%) infants underwent cardiac surgery with hypothermia during cardiopulmonary bypass (median temperature 30.3°C, interquartile range 27.0-32.0°C) at a median age of 96 (40-188) days. Seven (29.2%, 95% confidence interval 14.9-49.2%) patients died within the first year after cardiac surgery. Survival rates decreased with increasing STAT mortality category of the surgical procedure. Neurodevelopmental impairment at 2 years of corrected age was found in 9 out of 17 (52.9%) surviving infants, with 8 infants (47.1%) presenting with a cognitive deficit or delay and 4 infants (23.5%) being diagnosed with cerebral palsy. Survival without neuro-developmental impairment was 29.2% (n = 7, 95% confidence interval 14.9-49.2%) in the entire study cohort. Eighty percent of the newborns with dextro-transposition of the great arteries, but no patient with univentricular anatomy, survived without neuro-developmental impairment. CONCLUSIONS: Individual VLBW infants with severe CHD may develop well despite the high combined risk for adverse outcomes. The type of cardiac malformation may affect early- and long-term outcomes.

Right ventricular function and vasoactive peptides for early prediction of bronchopulmonary dysplasia.

BACKGROUND: To assess the prognostic value of early echocardiographic indices of right ventricular function and vasoactive peptides for prediction of bronchopulmonary dysplasia (BPD) or death in very preterm infants. METHODS: Prospective study involving 294 very preterm infants (median [IQR] gestational age 28.4 [26.4-30.4] weeks, birth weight 1065 [800-1380] g), of whom 57 developed BPD (oxygen supplementation at 36 weeks postmenstrual age) and 10 died. Tricuspid annular plane systolic excursion (TAPSE), right ventricular index of myocardial performance (RIMP), plasma concentrations of mid-regional pro-atrial natriuretic peptide (MR-proANP) and C-terminal pro-endothelin-1 (CT-proET1) were measured on day 7 of life. RESULTS: RIMP was significantly increased (median [IQR] 0.3 [0.23-0.38] vs 0.22 [0.15-0.29]), TAPSE decreased (median [IQR] 5.0 [5.0-6.0] vs 6.0 [5.4-7.0] mm), MR-proANP increased (median [IQR] 784 [540-936] vs 353 [247-625] pmol/L), and CT-proET1 increased (median [IQR] 249 [190-345] vs 199 [158-284] pmol/L) in infants who developed BPD or died, as compared to controls. All variables showed significant but weak correlations with each other (rS -0.182 to 0.359) and predicted BPD/death with similar accuracy (areas under receiver operator characteristic curves 0.62 to 0.77). Multiple regression revealed only RIMP and birth weight as independent predictors of BPD or death. CONCLUSIONS: Vasoactive peptide concentrations and echocardiographic assessment employing standardized measures, notably RIMP, on day 7 of life are useful to identify preterm infants at increased risk for BPD or death.

Preoperative Anemia and Outcomes After Corrective Surgery in Neonates With Dextro-Transposition of the Great Arteries.

OBJECTIVES: The authors aimed to assess whether untreated preoperative anemia was associated with increased risk for adverse outcomes after the arterial switch operation in neonates with dextro-transposition of the great arteries (d-TGA). DESIGN: Retrospective cohort study. SETTING: Single cardiac surgery center. PARTICIPANTS: Eighty-two newborns with d-TGA. INTERVENTIONS: The authors categorized the cohort into the following two groups: the infants with preoperative anemia group (defined as a hematocrit <0.40 L/L) and the control group. MEASUREMENTS AND MAIN RESULTS: Preoperative anemia was diagnosed in 21 (25.6%) infants. Anemic infants received intraoperative red blood cell transfusions significantly more often than controls (81.0% v 34.4%, p < 0.001). No differences were observed in the incidence of adverse events, duration of hospitalization (median 27 days v 26 days, p = 0.881), and mortality (0% v 4.9%, p = 0.566). Postnatal hematocrit was the only variable independently associated with preoperative anemia in multivariate logistic regression analysis (unit odds ratio, 0.832; 95% confidence interval, 0.743-0.931; p = 0.001). CONCLUSIONS: Untreated preoperative anemia was not associated with adverse outcomes in neonates undergoing reparative surgery for d-TGA.

Hypothermia for cardiogenic encephalopathy in neonates with dextro-transposition of the great arteries.

OBJECTIVES: Neonates with dextro-transposition of the great arteries (d-TGA) may experience rapid haemodynamic deterioration and profound hypoxaemia after birth. We report on d-TGA patients with severe acidosis, encephalopathy and their treatment with systemic hypothermia. METHODS: This study is a single-centre retrospective cohort analysis of newborns with d-TGA. RESULTS: Ninety-five patients (gestational age ≥35 weeks) with d-TGA and intended arterial switch operation were included. Ten infants (10.5%) with umbilical arterial blood pH > 7.10 experienced profound acidosis (pH < 7.00) within the first 2 h of life. Six of these patients displayed signs of encephalopathy and received therapeutic hypothermia. Apgar scores at 5 min independently predicted the development of neonatal encephalopathy during postnatal transition (unit Odds Ratio 0.17, 95% confidence interval 0.06-0.49, P = 0.001). Infants treated with hypothermia had a more severe preoperative course and required more often mechanical ventilation (100% vs 35%, P = 0.003), treatment with inhaled nitric oxide (50% vs 2.4%, P = 0.002) and inotropic support (67% vs 3.5%, P < 0.001), as compared to non-acidotic controls. The median age at cardiac surgery was 12 (range 6-14) days in cooled infants and 8 (4-59) days in controls (P = 0.088). Postoperative morbidity and total duration of hospitalization were not increased in infants receiving preoperative hypothermia. Mortality in newborns with severe preoperative acidosis was zero. CONCLUSIONS: Newborn infants with d-TGA have a substantial risk for profound acidosis during the first hours of life. Systemic hypothermia for encephalopathic patients may delay corrective surgery without compromising perioperative outcomes.

Therapeutic Hypothermia After Perinatal Asphyxia in Infants With Severe, Ductal-Dependent Congenital Heart Disease.

OBJECTIVES: Patients with severe congenital heart disease and cardiac anomalies such as restrictive foramen ovale, intact atrial septum, or narrowing of ductus arteriosus are at risk for perinatal asphyxia, leading to hypoxic-ischemic encephalopathy. We hypothesize that therapeutic hypothermia can be applied to these patients and seek to investigate feasibility and safety of this method. DESIGN: A retrospective observational study. SETTING: The Department of Neonatology of Charité, University Hospital, Berlin, Germany. PATIENTS: Newborns with severe congenital heart disease and perinatal asphyxia were retrospectively analyzed over a 6-year period. INTERVENTIONS: Application of therapeutic hypothermia. MEASUREMENTS AND MAIN RESULTS: Ten patients with perinatal asphyxia were enrolled in this study. All patients received low-dose prostaglandin E1 for ductal maintenance. Three patients without evidence for hypoxic-ischemic encephalopathy did not receive therapeutic hypothermia. One patient died at the age of 15 hours, and therapeutic hypothermia was discontinued after 19 hours in another patient with severe arterial hypotension. Adverse effects during hypothermia included respiratory insufficiency (100%), arterial hypotension (71%), the need for inotropic support (71%), and pulmonary hypertension (43%), the latter associated with prolonged postoperative inotropic support. No neurologic complications occurred before or after the surgery. Operative outcome of surviving patients was excellent. Early brain MRI scans were suggestive of good neurodevelopmental prognosis for most patients. CONCLUSIONS: Therapeutic hypothermia can be applied to patients with severe congenital heart disease and hypoxic-ischemic encephalopathy. Low-dose prostaglandin E1 infusions are safe for ductal maintenance during cooling, but cardiopulmonary adverse effects should be anticipated.

A critical role for Fas/CD-95 dependent signaling pathways in the pathogenesis of hyperoxia-induced brain injury.

OBJECTIVE: Prematurely born infants are at risk for development of neurocognitive impairment in later life. Oxygen treatment has been recently identified as a trigger of neuronal and oligodendrocyte apoptosis in the developing rodent brain. We investigated the role of the Fas death receptor pathway in oxygen-triggered developmental brain injury. METHODS: Six-day-old Wistar rats were exposed to 80% oxygen for various periods (2, 6, 12, 24, 48, and 72 hours), and mice deficient in either Fas (B6.MRL-Tnfrsf6(lpr)) or Fas ligand (B6Smn.C3-Fasl(gld)) and control mice (C57BL/6J) were exposed to 80% oxygen for 24 hours. Polymerase chain reaction, Western blotting, and caspase activity assays of thalamus and cortex tissue were performed. RESULTS: Fas and Fas ligand messenger RNA and protein were upregulated. Furthermore, hyperoxia resulted in induction of downstream signaling events of Fas, such as Fas-associated death domain (FADD), the long and short form of FADD-like interleukin-1beta-converting enzyme (FLICE) inhibitory protein (FLIP-L, FLIP-S), and cleavage of caspase-8 and caspase-3. Injection of a selective caspase-8 inhibitor (TRP801, 1mg/kg) at the beginning of hyperoxia blocked subsequent caspase-3 cleavage in this model. B6.MRL-Tnfrsf6(lpr) mice were protected against oxygen-mediated injury, confirming Fas involvement in hyperoxia-induced cell death. Mice deficient in Fas ligand did not differ from control animals in the amount of cell death. INTERPRETATION: We conclude that neonatal hyperoxia triggers Fas receptor and its downstream signaling events in a Fas ligand-independent fashion. Lack of functional Fas receptors and selective pharmacological inhibition of caspase-8 prevents activation of caspase-3 and provides significant neuroprotection.