Cardiac troponin I concentrations in neonates with hypoxic-ischaemic encephalopathy

Evaluation of Myocardial Injury Using Serum Cardiac Troponin-I in Asphyxiated Neonates at Enugu State University Teaching Hospital, Enugu, South-East Nigeria

BACKGROUND

The burden of perinatal asphyxia remains high in our environment and when asphyxia is severe, vital organs are affected, with resultant multiorgan hypoxic-iscahemic injury to the heart, the brain, adrenals and other organs.

STUDY AIM

To evaluate for myocardial injury in asphyxiated term neonates with hypoxic ischaemic encephalopathy using serum cardiac troponin-I (cTnI).

METHODS

The study was a hospital-based descriptive cross-sectional study involving sixty term asphyxiated neonates and sixty gestational age-and sex-matched controls. The subjects were term neonates with five-minute Apgar score ≤ 6 and HIE while the controls were healthy term neonates with five-minute Apgar score > 6. Five-minute Apgar score was utilized to classify asphyxia into mild, moderate and severe asphyxia. The degree of encephalopathy was determined by modified Sarnat and Sarnat criteria. The serum cTnI was measured in subjects and controls at 12-24 hours of life using Enzyme-linked immunosorbent assay technique. The serum bilirubin levels were also measured in participants to exclude hyperbilirubinemia.

RESULTS

The median serum cTnI levels was significantly higher in the subjects (0.56ng/mL; 0.25-0.94ng/mL) than in the controls (0.50ng/mL; 0.00-0.67ng/mL), respectively; p=0.001. Similarly, the median serum cTnI level in HIE stage II (0.56ng/mL; 0.38-0.72ng/mL) or III (0.56ng/ml; 0.50-0.94ng/mL) was also significantly higher than the median value in HIE stage I (0.38ng/mL;0.25-0.72ng/mL) or in controls (0.50ng/mL; 0.00-0.67ng/mL); p<0.001. There was significant positive correlation between serum cTnI levels and severity of HIE in asphyxiated neonates (rs = 0.505, p < 0.001).

CONCLUSION

serum cTnI levels were elevated in severely asphyxiated neonates with HIE. The concentration of serum cTnI demonstrated significant positive correlation with HIE severity. Hence, the presence of HIE in asphyxiated neonates should prompt an evaluation for myocardial injury using serum cTnI. Any derangement noted should warrant instituting cardiovascular support in order to improve outcome and reduce asphyxia-related mortality.

Pilot Study Investigating Brain Natriuretic Peptide, Troponin, Galectin-3, and miRNA-126a-5p as Biomarkers of Persistent Pulmonary Hypertension in Neonates with Hypoxic-Ischemic Injury Receiving Therapeutic Hypothermia

OBJECTIVE

The objective was to evaluate the utility of brain natriuretic peptide (BNP), troponin, galectin-3 (Gal-3), and microRNA (miRNA)-126a-5p as screening biomarkers for persistent pulmonary hypertension of the newborn (PPHN) by comparing expression in serum of infants with hypoxic-ischemic injury that develop PPHN to those that do not.

STUDY DESIGN

This was a prospective, observational pilot study including neonates with hypoxic-ischemic injury undergoing therapeutic hypothermia (TH) at two regional perinatal medical centers. PPHN in this population was diagnosed clinically and confirmed by echocardiogram. Serial measurements of biomarkers were performed from 6 to 96 hours post-TH initiation in 40 patients.

RESULTS

Of 40 infants in the study, 10 (25%) developed PPHN and 30 (75%) did not. Baseline demographics and hemodynamics were similar between the groups. Patients with PPHN had a significantly higher need for vasopressors compared with patients without PPHN (70 vs. 27%, p = 0.007). Mean serum BNP and troponin levels were significantly higher in the PPHN group peaking at 12 to 24 hours and decreasing following PPHN treatment initiation. miRNA-126a-5p expression was increased in patients with PPHN compared with patients without, with statistical significance detected at 12 hours (p = 0.005) and 96 hours (p = 0.01). Mean circulating Gal-3 levels were not statistically different between the two groups; however, Gal-3 was elevated in all patients with hypoxic-ischemic injury on TH compared with healthy infants from prior studies.

CONCLUSION

BNP and troponin are readily available, low-cost biomarkers that showed significant serial elevations in the PPHN group of the study and, thus, may have value in screening for PPHN in the setting of hypoxic-ischemic encephalopathy (HIE). Gal-3 was elevated in all patients with HIE and may be a useful biomarker of hypoxic injury in infants being evaluated for TH. Elevations in miRNA-126a-5p were not consistently seen in this study. Larger studies are required to establish an association between PPHN and these biomarkers in patients with and without HIE.

KEY POINTS

· Serum biomarkers of persistent pulmonary hypertension of the newborn. · Serum biomarkers of hypoxic-ischemic injury.

Asphyxia, Therapeutic Hypothermia, and Pulmonary Hypertension

Neonates with a perinatal hypoxic insult and subsequent neonatal encephalopathy are at risk of acute pulmonary hypertension (aPH) in the transitional period. The phenotypic contributors to aPH following perinatal asphyxia include a combination of hypoxic vasoconstriction of the pulmonary vascular bed, right heart dysfunction, and left heart dysfunction. Therapeutic hypothermia is the standard of care for neonates with moderate-to-severe hypoxic ischemic encephalopathy. This review summarizes the underlying risk factors, causes of aPH in neonates with perinatal asphyxia, discusses the unique phenotypical contributors to disease, and explores the impact of the initial insult and subsequent therapeutic hypothermia on aPH.

Troponin I, CK-MB, and inotropic score in hypoxic-ischemic encephalopathy and associated infant mortality

PURPOSE

Cardiovascular dysfunction is common in hypoxic-ischemic encephalopathy (HIE), which is one of the leading causes of multi-organ failure in neonates. We aimed to assess troponin I and creatine kinase myocardial band (CK-MB) levels, inotropic score (IS) in HIE patients, and their associations with HIE staging and mortality.

METHOD

The medical records of all HIE infants admitted to our unit between 2016 and 2018 were retrospectively analyzed. Demographic characteristics of the infants, seizures, anticonvulsive therapies, maximum inotrope doses, and the derived IS (dopamine dose [µg/kg/min] + dobutamine dose [µg/kg/min] + 100 × epinephrine dose [µg/kg/min]) and CK-MB and troponin-I levels obtained in the first six hours of life were compared according to HIE staging. Comparisons between survivors and non-survivors were made.

RESULTS

The study included data from 195 patients. Twenty-five patients were classified as stage 3, 116 as stage 2, and 54 as stage 1 HIE. Median Troponin-I, CK-MB level, and IS significantly differed by HIE staging (p < 0.01). The deceased infants had significantly higher median troponin I level [0.36 (0.02-3) vs. 0.16 (0.01-1.1) ng/ml; p = 0.006], median IS [20 (5-120) vs. 5 (5-10); p < 0.001], however, CK-MB values were comparable with survivors [129 (51-300) vs. 60.7 (31-300) ng/ml; p = 0.57]. The area under the curve was 0.93 for IS and 0.81 for Troponin I to predict mortality.

CONCLUSION

Troponin I, CK-MB, and IS could be successfully used as disease severity markers in HIE furthermore, troponin I and IS, are good predictors of mortality. These results need to be confirmed with larger prospective multi-center studies.

Early Troponin I Levels in Newborns Undergoing Therapeutic Hypothermia for Hypoxic Ischemic Encephalopathy and Residual Encephalopathy at Discharge

OBJECTIVE

Elevation of serum troponin I has been reported in newborns with hypoxic ischemic encephalopathy (HIE), but it is diagnostic and prognostic utility for newborn under 6 hours is not clear. Study the predictive value of early serum troponin I levels in newborns with HIE undergoing therapeutic hypothermia (TH) for persistent residual encephalopathy (RE) at discharge.

STUDY DESIGN

Retrospective chart review of newborns admitted with diagnosis of HIE to neonatal intensive care unit (NICU) for TH over a period of 3 years. Troponin levels were drawn with the initial set of admission laboratories while initiating TH. Newborns were followed up during hospital course and stratified into three groups based on predischarge examination and their electrical encephalography and cranial MRI findings: Group 1: no RE, Group 2: mild-to-moderate RE, and Group 3: severe RE or needing assisted medical technology or death. Demographic and clinical characteristics including troponin I levels were compared in each group.

RESULTS

Out of 104 newborns who underwent TH, 65 infants were in Group 1, 26 infants in Group 2, and 13 newborns in Group 3. All groups were comparable in demographic characteristics. There was a significant elevation of serum troponin in group 2 (mild-to-moderate RE) and group 3 (severe RE) as compared with group 1 (no RE). Receiver operator curve analysis for any RE (groups 2 and 3) compared with group 1 (no RE as control) had 0.88 (0.81-0.95) area under curve, p < 0.001. A cut-off level of troponin I ≥0.12 µg/L had a sensitivity of 77% and specificity of 78% for diagnosis of any RE, positive predictive value of 68%, and a negative predictive value of 84%.

CONCLUSION

In newborns undergoing TH for HIE, the elevation of troponin within 6 hours of age predicts high risk of having RE at discharge.

KEY POINTS

· Troponin I elevation is a biomarker of myocardial ischemia in adults and children.. · Myocardial ischemia may be part of multi-organ injury in neonatal HIE.. · Early elevation of troponin I level may correlate with the severity of neonatal HIE and predict residual encephalopathy in newborn at discharge from initial hospitalization..

Risk Factors for Clinical Seizures in Neonates with Hypoxic-ischemic Encephalopathy Treated with Therapeutic Hypothermia

BACKGROUND

This study aimed to assess the risk factors for clinical seizures in newborns treated with whole body cooling (WBC) for hypoxic ischemic encephalopathy (HIE).

METHODS

Infants with gestational age≥36 weeks and birth weight≥2.000 g who were treated with WBC due to HIE were retrospectively enrolled in this study. Patients were assigned to two groups: infants without clinical seizures (Group 1) and infants with clinical seizures (Group 2). The two groups were compared to determine the risk factors for the occurrence of clinical seizures.

RESULTS

A total of 25 patients (Group 1=10 and Group 2=15) were included in the study. Prothrombin time (PT) was determined as independent risk factor for clinical seizures (p=0.046) and the odds ratio for the effect of PT was found as 1.475 (%95 CI:1.006-2.299). PT (area under the curve [AUC]=0.764; p=0.041), and increased cardiac troponin-I (cTnI) (AUC=0.935; p=0.002) were found to be significant risk factors for predicting the occurrence of clinical seizures. The optimal PT cut-off value was 22.7 sec, with a sensitivity and specificity of 45.4% and 90%, respectively; as well as positive and negative predictive value of 83.3% and 60.0%, respectively. The chest compression in the delivery room, severely abnormal amplitude integrated electroencephalography and high encephalopathy score were also found risk factors for occurrence of clinical seizures.

CONCLUSION

Chest compression in the delivery room, high encephalopathy score, prolonged PT, and increased cTnI are significant factors for clinical seizures in newborns treated with WBC for HIE.

Serum troponin I: a potential biomarker of hypoxic-ischemic encephalopathy in term newborns

OBJECTIVE

This study was intended to evaluate the predictive values of serum procalcitonin (PCT), lactate, creatine kinase (CK-MB), and troponin I on the diagnosis and staging of neonatal hypoxic-ischemic encephalopathy (HIE).

MATERIALS AND METHODS

We retrospectively retrieved data from electronic medical records at our children's hospital, and we included all term newborns admitted between December 2018 and June 2020 with features of perinatal asphyxia. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to measure and evaluate the predictive values of biomarkers. p values < 0.05 were set as statistical significance.

RESULTS

A total of 201 neonates were included. They were grouped as control (n = 40), mild HIE (n = 105), moderate HIE (n = 36), and severe HIE (n = 20). Serum lactate, PCT, CK-MB, and troponin I levels in severe hypoxic-ischemic brain injury group were significantly higher than those in mild to moderate hypoxic-ischemic brain injury group and control group (p < 0.05). Based on ROC and AUC analysis, troponin I showed highest predictive ability with AUC of 0.904, and sensitivity and specificity of 95.00% and 87.50% respectively.

CONCLUSION

Serum troponin I has a good predictive value for neonatal hypoxic-ischemic encephalopathy after perinatal asphyxia.

Troponin I Levels in Neonatal Hypoxic-Ischemic Encephalopathy Are Related to Cardiopulmonary Comorbidity and Neurodevelopmental Outcomes

Troponin I is a biomarker for cardiac injury in children. The role of troponin I in neonatal Hypoxic-Ischemic encephalopathy (HIE) may have valuable clinical implications. Troponin I levels were measured within 6 h of birth to determine their relationship to HIE stage, short-term cardiac functional outcomes, and neurodevelopmental outcomes at 1 year. Seventy-three patients were divided into two groups: mild HIE and moderate to severe HIE. Troponin I levels within 6 h of birth were obtained in 61 patients, and were significantly higher in patients with moderate to severe HIE than in patients with mild HIE (Mann-Whitney U test, U = 146, p = 0.001). A troponin I cut-off level of ≥60 pg/mL predicted moderate to severe HIE with a specificity of 81.1% and a negative prediction rate of 76.9%. A troponin I cut-off level of ≥180 pg/mL was significantly (χ2 (1, n = 61) = 33.1, p = 0.001, odds ratio 96.8) related with hypotension during first admission and significantly (χ2 (1, n = 61) = 5.3, p = 0.021, odds ratio 4.53) related with abnormal neurodevelopmental outcomes at 1 year. Early troponin I level may be a useful biomarker for predicting moderate to severe HIE, and initialization of hypothermia therapy.

Hemodynamic optimization for neonates with neonatal encephalopathy caused by a hypoxic ischemic event: Physiological and therapeutic considerations

Neonatal encephalopathy due to a hypoxic-ischemic event is commonly associated with cardiac dysfunction and acute pulmonary hypertension; both therapeutic hypothermia and rewarming modify loading conditions and blood flow. The pathophysiological contributors to disease are complex with a high degree of clinical overlap and traditional bedside measures used to assess circulatory adequacy have multiple confounders. Comprehensive, quantitative echocardiography may be used to delineate the relative contribution of lung parenchymal, pulmonary vascular, and cardiac disease to hypotension and/or hypoxemic respiratory failure. In this review, we provide a detailed overview of the contributors to hemodynamic instability following perinatal hypoxic-ischemic injury. Our proposed approach to therapy focuses on physiopathological considerations with interventions individualized to this potentially complex condition and considers the pharmacological idiosyncrasies, which may occur among neonates with NE presenting with multiorgan dysfunction while undergoing therapeutic hypothermia.

Thermal Index for early non-invasive assessment of brain injury in newborns treated with therapeutic hypothermia: preliminary report

Perinatal asphyxia (PA) is the 3rd most common cause of neonatal death and one of the most common causes of severe neurological impairments in children. Current tools and measurements mainly based on the analysis of clinical evaluation and laboratory and electrophysiological tests do not give consistent data allowing to predict the severity of hypoxic-ischemic encephalopathy (HIE) until a magnetic resonance imaging (MRI) score is performed. The aim of this work is to evaluate the usefulness of the new index, called Thermal Index (TI) in the assessment of the degree of brain damage in newborns in the course of therapeutic hypothermia (TH) due to PA. This was a prospective, observational, pilot study which did not require any changes in the applicable procedures. Analysis has been applied to six newborn babies treated with TH in Neonatal/Paediatric ICU in University Hospital in Opole in 2018 due to PA. They all met criteria for TH according to the current recommendations. Brain MRI was performed after the end of TH when the children were brought back to normal temperature, with the use of a 1.5 T scanner, using T1-, T2-weighted images, fluid-attenuated inversion recovery (FLAIR), inversion recovery (IR), susceptibility-weighted imaging (SWI), and diffusion-weighted imaging (DWI). The images were assessed using MRI score according to the scoring system proposed by Weeke et al. The Thermal Index assessing endogenous heat production was calculated according to the formula proposed in this paper. A high, statistically significant positive correlation was found between MRI scores and TI values (0.98; p = 0.0003) in the 1st hour of therapy. High correlation with MRI assessment, the non-invasiveness of measurements and the availability of results within the first few hours of treatment, allow authors to propose the Thermal Index as a tool for early evaluating of the brain injury in newborns treated with TH. Further research is required to confirm the usefulness of the proposed method.

Effect of therapeutic hypothermia on renal and myocardial function in asphyxiated (near) term neonates: A systematic review and meta-analysis

BACKGROUND

Therapeutic hypothermia (TH) is a well-established neuroprotective therapy applied in (near) term asphyxiated infants. However, little is known regarding the effects of TH on renal and/or myocardial function.

OBJECTIVES

To describe the short- and long-term effects of TH on renal and myocardial function in asphyxiated (near) term neonates.

METHODS

An electronic search strategy incorporating MeSH terms and keywords was performed in October 2019 and updated in June 2020 using PubMed and Cochrane databases. Inclusion criteria consisted of a RCT or observational cohort design, intervention with TH in a setting of perinatal asphyxia and available long-term results on renal and myocardial function. We performed a meta-analysis and heterogeneity and sensitivity analyses using a random effects model. Subgroup analysis was performed on the method of cooling.

RESULTS

Of the 107 studies identified on renal function, 9 were included. None of the studies investigated the effects of TH on long-term renal function after perinatal asphyxia. The nine included studies described the effect of TH on the incidence of acute kidney injury (AKI) after perinatal asphyxia. Meta-analysis showed a significant difference between the incidence of AKI in neonates treated with TH compared to the control group (RR = 0.81; 95% CI 0.67-0.98; p = 0.03). No studies were found investigating the long-term effects of TH on myocardial function after neonatal asphyxia. Possible short-term beneficial effects were presented in 4 out of 5 identified studies, as observed by significant reductions in cardiac biomarkers and less findings of myocardial dysfunction on ECG and cardiac ultrasound.

CONCLUSIONS

TH in asphyxiated neonates reduces the incidence of AKI, an important risk factor for chronic kidney damage, and thus is potentially renoprotective. No studies were found on the long-term effects of TH on myocardial function. Short-term outcome studies suggest a cardioprotective effect.

Biomarkers in newborns with hypoxic-ischemic encephalopathy treated with therapeutic hypothermia

PURPOSE

The aim of the presented study was to evaluate the differences between selected biochemical markers in infants with moderate or severe hypoxic-ischemic encephalopathy (HIE) and their impact on patient prognosis.

METHODS

A total of 57 cooled newborns were divided into groups according to Sarnat staging of HIE (A, moderate vs. B, severe). The differences between groups were evaluated depending on the mode of delivery, pregnancy and labor complications, gestational age at birth, birth weight, and Apgar score at 1.3 and 5 min. The differences in biochemical biomarkers of HIE (pH, base excess, serum lactate) as well as biomarkers of hepatic injury (aspartate transaminase, (AST), alanine transaminase (ALT), prothrombin time (PT), and activated partial thromboplastin time (APTT)), kidney failure (creatinine, urea), myocardial injury (troponin T (TnT)), levels of fibrinogen, and platelet counts were also examined. Univariate Kaplan-Meier method was used for survival analyses.

RESULTS

The biomarker levels in severe HIE newborns compared with moderate were as follows: pH (7.10 vs. 6.99), serum lactate (22.50 vs. 17.00 mg/dL), AST (109.50 vs. 270.55 IU/L), ALT (27.30 vs. 108.05 IU/L), PT (17.00 vs. 44.20 s), APTT (47.75 vs. 47.90 s), TnT (0.22 vs. 0.85 ng/mL), creatinine (0.68 vs. 1.15 mg/dL), urea (44.55 vs. 73.30 mg/dL), and fibrinogen (1.65 vs. 1.90 mg/dL). Survival analyses showed significantly reduced survival for severe HIE infants (75%) vs. moderate HIE (100%).

CONCLUSION

In conclusion, the severity of HIE can be evaluated based on selected markers; however, their levels do not correspond with future prognosis of newborns.

A retrospective study on the incidence of acute kidney injury and its early prediction using troponin-I in cooled asphyxiated neonates

Acute kidney injury (AKI) is a common complication of perinatal asphyxia and is associated with poorer short-term and long-term outcomes. This retrospective study describes the incidence of AKI in asphyxiated neonates who have received therapeutic hypothermia using the proposed modified Kidney Diseases: Improving Global Outcomes (KDIGO) definition and investigates clinical markers that would allow earlier recognition of at-risk neonates. We included asphyxiated  neonates who underwent therapeutic hypothermia between the period of January 2011 and May 2018 in our study. The serum creatinine levels within a week of birth were used in establishing AKI according to the modified KDIGO definition. Demographic data, resuscitation details, laboratory results and use of medications were collected and compared between the AKI and non-AKI groups to identify variables that differed significantly. A total of 66 neonates were included and 23 out of them (35%) were found to have AKI. The neonates with AKI had a lower gestational age (p = 0.006), lower hemoglobin level (p = 0.012), higher lactate level before and after therapeutic hypothermia (p = 0.013 and 0.03 respectively) and higher troponin-I level after therapeutic hypothermia (p < 0.001). After logistic regression analysis, elevated troponin-I after therapeutic hypothermia was independently associated with risk of AKI (OR 1.69, 95% CI 1.067–2.699, p = 0.025). The receiver operating curve showed that troponin-I after therapeutic hypothermia had an area under curve of 0.858 at the level 0.288 ng/ml. Our study concludes that the incidence of AKI among asphyxiated newborns who received therapeutic hypothermia is 35% and an elevated troponin-I level after therapeutic hypothermia is independently associated with an increased risk of AKI in asphyxiated newborns.

Use of high-sensitivity cardiac troponin I levels for early diagnosis of myocardial injury after neonatal asphyxia

Objective

Low-cost diagnostic and prognostic biomarkers could help guide clinical management of neonates with myocardial injury after asphyxia. This study aimed to assess the utility of creatine kinase (CK)-MB, high-sensitivity cardiac troponin I (hs-cTnI), brain natriuretic peptide (BNP), and myoglobin in the early diagnosis of myocardial injury following neonatal asphyxia.

Methods

Eighteen neonates with asphyxia and myocardial injury, 22 neonates with asphyxia and no myocardial injury, and 19 neonates without asphyxia (controls) were enrolled consecutively at the Neonatology Department, First Hospital of Lanzhou University (August 2013 to December 2014). Serum CK-MB, hs-cTnI, BNP, and myoglobin levels were evaluated at 12 hours and 7 days after birth. Their diagnostic value for myocardial injury was assessed by receiver operating characteristic (ROC) curve analysis.

Results

Levels of all four markers were higher in neonates with asphyxia and myocardial injury than in neonates with asphyxia and no myocardial injury or controls 12 hours after birth. The marker hs-cTnI had the highest diagnostic value. Using a cutoff value of 0.087 µg/L for hs-cTnI, the sensitivity, specificity, and diagnostic accuracy for asphyxia-induced myocardial injury were 55.6%, 95.5%, and 77.5%, respectively.

Conclusions

Serum hs-cTnI levels can predict myocardial injury caused by neonatal asphyxia at an early stage.

Mechanisms of death in structurally normal stillbirths

Objectives To investigate mechanisms of in utero death in normally formed fetuses by measuring amniotic fluid (AF) biomarkers for hypoxia (erythropoietin [EPO]), myocardial damage (cardiac troponin I [cTnI]) and brain injury (glial fibrillary acidic protein [GFAP]), correlated with risk factors for fetal death and placental histopathology. Methods This retrospective, observational cohort study included intrauterine deaths with transabdominal amniocentesis prior to induction of labor. Women with a normal pregnancy and an indicated amniocentesis at term were randomly selected as controls. AF was assayed for EPO, cTnI and GFAP using commercial immunoassays. Placental histopathology was reviewed, and CD15-immunohistochemistry was used. Analyte concentrations >90th centile for controls were considered "raised". Raised AF EPO, AF cTnI and AF GFAP concentrations were considered evidence of hypoxia, myocardial and brain injury, respectively. Results There were 60 cases and 60 controls. Hypoxia was present in 88% (53/60), myocardial damage in 70% (42/60) and brain injury in 45% (27/60) of fetal deaths. Hypoxic fetuses had evidence of myocardial injury, brain injury or both in 77% (41/53), 49% (26/53) and 13% (7/53) of cases, respectively. Histopathological evidence for placental dysfunction was found in 74% (43/58) of these cases. Conclusion Hypoxia, secondary to placental dysfunction, was found to be the mechanism of death in the majority of fetal deaths among structurally normal fetuses. Ninety-one percent of hypoxic fetal deaths sustained brain, myocardial or both brain and myocardial injuries in utero. Hypoxic myocardial injury was an attributable mechanism of death in 70% of the cases. Non-hypoxic cases may be caused by cardiac arrhythmia secondary to a cardiac conduction defect.

Neonatal Encephalopathy: Need for Recognition of Multiple Etiologies for Optimal Management

Neonatal encephalopathy (NE) is associated with high mortality and morbidity. Factors predisposing to NE can be antenatal, perinatal, or a combination of both. Antenatal maternal factors, familial factors, genetic predisposition, hypoxic ischemic encephalopathy, infections, placental abnormalities, thrombophilia, coagulation defects, and metabolic disorders all have been implicated in the pathogenesis of NE. At present, therapeutic hypothermia is the only treatment available, regardless of etiology. Recognizing the etiology of NE involved can also guide investigations such as metabolic and sepsis workups to ensure optimal management. Understanding the etiology of NE may allow the development of targeted adjunctive therapies related to the underlying mechanism and develop preventative strategies.

Misoprostol regulates Bnip3 repression and alternative splicing to control cellular calcium homeostasis during hypoxic stress

The cellular response to hypoxia involves the activation of a conserved pathway for gene expression regulated by the transcription factor complex called hypoxia-inducible factor (HIF). This pathway has been implicated in both the adaptive response to hypoxia and in several hypoxic-ischemic-related pathologies. Perinatal hypoxic injury, often associated with prematurity, leads to multi-organ dysfunction resulting in significant morbidity and mortality. Using a rodent model of neonatal hypoxia and several representative cell lines, we observed HIF1α activation and down-stream induction of the cell death gene Bnip3 in brain, large intestine, and heart which was mitigated by administration of the prostaglandin E1 analog misoprostol. Mechanistically, we determined that misoprostol inhibits full-length Bnip3 (Bnip3-FL) expression through PKA-mediated NF-κB (P65) nuclear retention, and the induction of pro-survival splice variants. We observed that the dominant small pro-survival variant of Bnip3 in mouse cells lacks the third exon (Bnip3ΔExon3), whereas human cells produce a pro-survival BNIP3 variant lacking exon 2 (BNIP3ΔExon2). In addition, these small Bnip3 splice variants prevent mitochondrial dysfunction, permeability transition, and necrosis triggered by Bnip3-FL by blocking calcium transfer from the sarco/endoplasmic reticulum to the mitochondria. Furthermore, misoprostol and Bnip3ΔExon3 promote nuclear calcium accumulation, resulting in HDAC5 nuclear export, NFAT activation, and adaptive changes in cell morphology and gene expression. Collectively, our data suggests that misoprostol can mitigate the potential damaging effects of hypoxia on multiple cell types by activating adaptive cell survival pathways through Bnip3 repression and alternative splicing.

LyTONEPAL: long term outcome of neonatal hypoxic encephalopathy in the era of neuroprotective treatment with hypothermia: a French population-based cohort

Background

Hypoxic-ischemic encephalopathy (HIE) is a rare neonatal condition affecting about 1‰ births. Despite a significant improvement in the management of this condition in the last ten years, HIE remains associated with high rates of death and severe neurological disability. From September 2015 to March 2017, a French national cohort of HIE cases was conducted to estimate the extent of long-term moderate and severe neurodevelopmental disability at 3 years and its determinants.

Methods

This prospective population-based cohort includes all moderate or severe cases of HIE, occurring in newborns delivered between 34 and 42 completed weeks of gestation and admitted to a neonatal intensive care unit. Detailed data on the pregnancy, delivery, and newborn until hospital discharge was collected from the medical records in maternity and neonatology units. All clinical examinations including biomarkers, EEG, and imaging were recorded. To ensure the completeness of HIE registration, a registry of non-included eligible neonates was organized, and the exhaustiveness of the cohort is currently checked using the national hospital discharge database. Follow-up is organized by the regional perinatal network, and 3 medical visits are planned at 18, 24 and 36 months. One additional project focused on early predictors, in particular early biomarkers, involves a quarter of the cohort.

Discussion

This cohort study aims to improve and update our knowledge about the incidence, the prognosis and the etiology of HIE, and to assess medical care. Its final objective is to improve the definition of this condition and develop prevention and management strategies for high-risk infants.

Trial registration

NCT02676063. Date of registration (Retrospectively Registered): February 8, 2016.

Application of Neonatologist Performed Echocardiography in the Assessment and Management of Neonatal Heart Failure unrelated to Congenital Heart Disease

Neonatal heart failure (HF) is a progressive disease caused by cardiovascular and non-cardiovascular abnormalities. The most common cause of neonatal HF is structural congenital heart disease, while neonatal cardiomyopathy represents the most common cause of HF in infants with a structurally normal heart. Neonatal cardiomyopathy is a group of diseases manifesting with various morphological and functional phenotypes that affect the heart muscle and alter cardiac performance at, or soon after birth. The clinical presentation of neonates with cardiomyopathy is varied, as are the possible causes of the condition and the severity of disease presentation. Echocardiography is the selected method of choice for diagnostic evaluation, follow-up and analysis of treatment results for cardiomyopathies in neonates. Advances in neonatal echocardiography now permit a more comprehensive assessment of cardiac performance that could not be previously achieved with conventional imaging. In this review, we discuss the current and emerging echocardiographic techniques that aid in the correct diagnostic and pathophysiological assessment of some of the most common etiologies of HF that occur in neonates with a structurally normal heart and acquired cardiomyopathy and we provide recommendations for using these techniques to optimize the management of neonate with HF.

Hyperdehydroepiandrosterone in neonates with hypoxic ischemic encephalopathy and circulatory collapse

BACKGROUND

Circulatory collapse is a very common complication of the critical illnesses in neonates including neonates with hypoxic ischemic encephalopathy; it can be the end result and cause of death of several conditions. Often, despite treatment with fluid resuscitation and vasopressor agents, circulatory collapse persist, and blood pressure can remain critically low, compromising adequate blood flow to vital organs and brain. Low blood pressure has been associated with increased mortality.

METHOD

To investigate adrenal function in newborn infants who suffer from circulatory collapse during hypoxic ischemic encephalopathy. A total of 30 infants were analyzed in the study: 15 neonates in group A (neonates had hypoxic ischemic encephalopathy with vasopressor resistant hypotension) and 15 neonates in group B (neonates with hypoxic ischemic encephalopathy without vasopressor resistant hypotension). All the studied patients were subjected to history, examinations and laboratory investigation including serum cortisol concentrations and cortisol precursor's levels.

RESULTS

The cortisol concentrations did not differ significantly between the two groups: (12.9 ± 4.3) μg/dL and (12.1 ± 2.4) μg/dL in group A and group B, respectively. There are highly significant differences between groups A and B regarding Dehydroepiandrosterone (342.1 ± 101.3) μg/dL, (33.4 ± 16.5) μg/dL, respectively.

CONCLUSION

In this study, we noticed that cortisol concentrations did not differ between both groups in contrast to the expectation that neonates with critical illnesses should have higher cortisol concentrations than normal neonates. However, the marked increase in dehydroepiandrosterone DHEA may cause decrease cortisol function, so those neonates having accumulation of dehydroepiandrosterone may suffer from manifestation of adrenal insufficiency and vasopressor resistant hypotension in spite of normal cortisol level.

Biomarkers of multiorgan injury in neonatal encephalopathy

Neonatal encephalopathy (NE) is a major contributor to neurodevelopmental deficits including cerebral palsy in term and near-term infants. The long-term neurodevelopmental outcome is difficult to predict with certainty in first few days of life. Multiorgan involvement is common but not part of the diagnostic criteria for NE. The most frequently involved organs are the heart, liver, kidneys and hematological system. Cerebral and organ involvement is associated with the release of organ specific biomarkers in cerebrospinal fluid, urine and blood. These biomarkers may have a role in the assessment of the severity of asphyxia and long-term outcome in neonates with NE.

Using adrenaline during neonatal resuscitation may have an impact on serum cardiac troponin-T levels

AIM

It has been suggested that serum cardiac troponin-T (cTnT) can predict the severity of neonatal hypoxic-ischaemic encephalopathy. We evaluated whether cTnT was better correlated with adrenaline during cardiopulmonary resuscitation (CPR) than with the severity of the insult itself, based on the Apgar scores.

METHODS

Serum cTnT was analysed in 47 asphyxiated newborn infants treated with hypothermia. Blood samples and resuscitation data were collected from medical records, and multiple linear regressions were used to evaluate the effect of the treatment and the Apgar scores on cTnT levels.

RESULTS

The infants were divided into three groups: the no CPR group (n = 29) just received stimulation and ventilation, the CPR minus adrenaline group (n = 9) received cardiac compression and ventilation and the CPR plus adrenaline group (n = 9) received complete CPR, including adrenaline. In the univariate analysis, the five and ten-minute Apgar scores were significantly lower in the CPR plus adrenaline group and the cTnT was significantly higher. Multiple regression analysis showed significantly higher cTnT values in the CPR plus adrenaline group, but no significant relationship between cTnT and the Apgar scores.

CONCLUSION

Although cTnT correlated with the severity of the insult in neonatal hypoxic-ischaemic encephalopathy, the levels may have been affected by adrenaline administered during CPR.

Serum liver enzyme pattern in birth asphyxia associated liver injury

PURPOSE

To study temporal pattern of serum liver enzymes levels in newborns with hepatic injury associated with birth asphyxia (BA).

METHODS

Singleton term newborns with BA and ≤72 hours of age admitted to neonatal intensive care unit were prospectively enrolled. Term newborns with physiological jaundice and without BA were studied as controls. Serum liver enzymes were measured at <24 hours, 24-72 hours, and at 6-12 days of age for cases and at 1-6 days of age for controls. BA was defined by 1 minute Apgar score <7 or delayed or absent cry with hypoxic ischemic encephalopathy. BA-associated liver injury was defined as serum alanine aminotransferase (ALT) elevation beyond +2 standard deviation (ALT > +2 SD) above the mean of control subjects at any of the three time points.

RESULTS

Sixty controls and 62 cases were enrolled. Thirty-five cases (56%) developed BA-associated liver injury (ALT>81 IU/L). They had higher serum levels of ALT, aspartate aminotransferase, lactate dehydrogenase than the control infants, with peak at 24-72 hours. In controls, serum liver enzyme levels were significantly higher in appropriate-for-date (AFD) babies than small-for-date (SFD) babies. Serum enzyme pattern and extent of elevation were comparable between SFD and AFD babies. Degree of serum liver enzyme elevation had no relationship with severity of hypoxic encephalopathy.

CONCLUSION

Serum liver enzyme elevation is common in BA; it peaks at 24-72 hours followed by a sharp decline by 6-12 days of age. Pattern and extent of enzyme elevation are comparable between SFD and AFD babies.

Cardiac troponin I concentrations as a marker of neurodevelopmental outcome at 18 months in newborns with perinatal asphyxia

OBJECTIVE

To investigate whether creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) can be used to predict neurodevelopmental outcome at 18 months in infants with perinatal asphyxia (PA). The diagnostic value of cTnI to assess myocardial dysfunction was considered as well.

STUDY DESIGN

Retrospective study of 178 neonates admitted with PA. cTnI concentrations measured within 12 h of birth were compared with medium-term outcome assessed with the Bayley Scales of Infant Development. cTnI concentrations measured within 12 h of birth were compared with clinical grade of hypoxic-ischemic encephalopathy (HIE) and with duration of inotropic support. Two-dimensional Doppler and color Doppler findings were recorded. Fractional shortening, tricuspid and mitral regurgitation were evaluated.

RESULT

A statistically significant correlation between cTnI concentration and BSID-II score was found (mental development index r -0.69, P<0.05 and psychomotor development index r -0.39, P<0.05). There was no statistically significant correlation between CK-MB and BSID-II score (P>0.05).Serum cTnI concentrations and duration of inotropic support were significantly greater with increasing severity of PA. cTnI was negatively correlated with fraction shortening (r -0.64; P<0.05). The severity of tricuspid regurgitation was correlated with the cTnI concentration (r 0.61; P<0.05).

CONCLUSION

In asphyxiated neonates, cTnI concentrations within 12 h of birth correlate with medium-term outcome. Early cTnI concentration correlates with severity of HIE, myocardial dysfunction and with Bayley II scores at 18 months.

Cardiac troponin I in healthy newborn goat kids and in goat kids with cardiac nutritional muscular dystrophy

This study was designed to establish serum cardiac troponin I (cTnI) concentrations in healthy newborn goat kids and in those with cardiac nutritional muscular dystrophy (NMD). Thirty-five single full-term newborn goat kids (20 males and 15 females; age: 6.1 ± 3.5 h; weight 3.4 ± 0.68 kg), together with their respective mothers (Group 1; G1) were enrolled consecutively. Thirty-one goat kids (age: 9.5 ± 4.3 days) with NMD, together with 20 control goat kids (age: 7.8 ± 4.3 days) were also included in this study (Group 2; G2). Blood samples were collected from G1 within 12 h of birth and from G2 on admission. Serum samples were collected and analysed for cTnI. In G1, the mean serum concentration of cTnI in goat kids was 0.290 ± 0.37 ng/mL, with no statistically significant difference between male and female kids (P = 0.61). The mean cTnI concentration in the does was 0.017 ± 0.04, ng/mL. Serum values of cTnI in the goat kids and in their respective mothers differed significantly (P = 0.0001). In G2, the mean cTnI concentration was 0.02 ± 0.05 ng/mL in the control and 11.18 ± 20.07 ng/mL in the diseased goat kids, with a statistically significant difference between diseased and control goat kids (P = 0.017). Serum concentrations of cTnI are higher in goat kids than in their respective mothers. In conclusion, the cTnI assay appears to be a sensitive and specific marker for myocardial injury in goat kids.

Troponin

Troponin T and I can be found within the myocardial filaments. Measuring these cardiac troponin levels in full-term newborns and premature infants has not become a common practice in the neonatal intensive care unit and newborn nurseries. Research studies are discovering that an elevation in troponin T and I levels can be directly correlated with the severity of the infant's illness, and it can be potentially prognostic of morbidity. This literature analysis discusses what can be considered normal cardiac troponin levels along with what elevated levels are and possible conditions associated with those elevations.

Effect of cardiac compressions and hypothermia treatment on cardiac troponin I in newborns with perinatal asphyxia

BACKGROUND

The American Heart Association, the European Resuscitation and the International Liaison Committee issued new neonatal resuscitation guidelines (2010) where therapeutic hypothermia is introduced after hypoxic-ischaemic encephalopathy (HIE) in term infants to prevent brain injury. Our study aimed to investigate whether hypothermia can reduce the release of a cardiac cellular marker, cardiac troponin I (cTnI), in HIE infants compared to normothermia care, if cTnI can be used as a prognostic marker for long term neuro-developmental outcome and if cardiac compression at birth affects the level of cTnI.

METHODS

We retrospectively collected resuscitation data at birth and cTnI levels for the first 3 days in HIE infants who fulfilled cooling entry criteria. These infants received either normothermia care or induced hypothermia treatment in the neonatal period and were then followed up and tested by standard cognitive and motor assessments. The outcome is defined as death, disability or good.

RESULTS

We confirmed an increase in cTnI after cardiac compressions (p=0.003, Mann-Whitney test). We found that hypothermia significantly reduced the release of cTnI (peak level and area under the curve within 24h of age), p=0.002, linear regression. Receiver operating characteristic curves showed a level of cTnI at 24 h of age <0.22 ng/ml for normothermic and <0.15 ng/ml for hypothermic infants predicts a good outcome.

CONCLUSIONS

Our results suggest that hypothermia is cardio protective after HIE. The level of cTnI at 24h of age is a good prognostic marker for neuro-developmental outcome at 18-22 months in both normothermia and hypothermia infants.

Use of cardiac biomarkers in neonatology

Cardiac biomarkers are used to identify cardiac disease in term and preterm infants. This review discusses the roles of natriuretic peptides and cardiac troponins. Natriuretic peptide levels are elevated during atrial strain (atrial natriuretic peptide (ANP)) or ventricular strain (B-type natriuretic peptide (BNP)). These markers correspond well with cardiac function and can be used to identify cardiac disease. Cardiac troponins are used to assess cardiomyocyte compromise. Affected cardiomyocytes release troponin into the bloodstream, resulting in elevated levels of cardiac troponin. Cardiac biomarkers are being increasingly incorporated into clinical trials as indicators of myocardial strain. Furthermore, cardiac biomarkers can possibly be used to guide therapy and improve outcome. Natriuretic peptides and cardiac troponins are potential tools in the diagnosis and treatment of neonatal disease that is complicated by circulatory compromise. However, clear reference ranges need to be set and validation needs to be carried out in a population of interest.

Therapeutic strategies to protect the immature newborn myocardium during resuscitation following asphyxia

Perinatal asphyxia contributes to over one million newborn deaths worldwide annually, and may progress to multiorgan failure. Cardiac dysfunction, of varying severity, is seen in 50%-70% of asphyxiated newborns. Resuscitation is necessary to restore oxygenation to deprived tissues, including the heart. However, reoxygenation of asphyxiated newborns may lead to generation of reactive oxygen species (ROS) and further myocardial damage, termed reperfusion injury. The newborn heart is especially vulnerable to oxidative stress and reperfusion injury due to immature antioxidant defense mechanisms and increased vulnerability to apoptosis. Currently, newborn myocardial protective strategies are aimed at reducing the generation of ROS through controlled reoxygenation, boosting antioxidant defenses, and attenuating cellular injury via mitochondrial stabilization.

Cardiac biomarkers as indicators of hemodynamic adaptation during postasphyxial hypothermia treatment

BACKGROUND

Little is known about the effects of hypothermia on the cardiovascular system in term newborns with neonatal encephalopathy.

OBJECTIVES

To evaluate whether mild hypothermia for neonatal encephalopathy is cardioprotective as indicated by the cardiac biomarkers cardiac troponin I (cTnI) and B-type natriuretic peptide (BNP).

METHODS

This was an observational cohort study of infants treated for perinatal asphyxia. In infants, mild total body hypothermia treatment of 33.5°C during 72 h was initiated (n = 20). Samples of cTnI and BNP were collected before the start of hypothermia, at 24 and 48 h after birth, and after rewarming (84 h). BNP and cTnI values were then compared with BNP and cTnI values of asphyxiated infants not treated with hypothermia (n = 28).

RESULTS

No differences were found between the groups in clinical patient characteristics or inotropic support. The hypothermia-treated patients seemed to be clinically more affected (5-min Apgar score, p < 0.05; umbilical artery pH, p = 0.08), but showed similar encephalopathy scores. Significantly lower values for BNP were found in hypothermia- compared to nonhypothermia-treated infants at 48 h and at normothermia after rewarming [144 pmol/l (95-286) vs. 75 pmol/l (45-143), 182 pmol/l (73-341) vs. 43 pmol/l (24-163)]. No differences were found for cTnI concentrations between both groups.

CONCLUSIONS

The raised, but similar, cTnI values between hypothermia- and nonhypothermia-treated infants indicate similar myocardial damage in both groups. The lower BNP levels during hypothermia treatment suggest that hypothermia after perinatal asphyxia exerts a beneficial effect on cardiac function.