Troponin-T levels in perinatally asphyxiated infants during the first 15 days of life

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.

Hemodynamic changes and evaluation during hypoxic-ischemic encephalopathy and therapeutic hypothermia

Multiorgan damage is a hallmark of hypoxic-ischemic encephalopathy and cardiovascular and hemodynamic changes during asphyxia contribute significantly to the brain damage. The main insult to the heart is myocardial damage and associated ventricular dysfunction, which is manifested by reduced preload and afterload. The immature myocardium reacts to asphyxia by bradycardia and reduced contractile capacity. Pulmonary hypertension aggrevates cardiac dysfunction. Hypothermia is the only effective treatment for HIE but it may also affect the heart and peripheral vascular system leading to bradycardia and peripheral vasoconstriction. In fact, these effects might be cardioprotective also. Rewarming after hypothermia may increase the heart rate and cardiac metabolism, augmenting the cardiac output. Monitoring of patient with HIE during and after hypothermia is possible by using near-infrared spectroscopy, echocardiography and electrocardiography. Cerebral effects may be monitored by magnetic resonance imaging also. Management should include the physiological status of the patient and appropriate treatments, including inotropes, vasopressors or rarely fluid boluses. Dopamine should not be used unless absolutely necessary. Drugs like melatonin and magnesium are under investigation. All treatments should be evidence-based and targeted echocardiography should be used more often in these vulnerable infants.

Correlation of cardiac troponin T levels with inotrope requirement, hypoxic-ischemic encephalopathy, and survival in asphyxiated neonates

BACKGROUND

Cardiac involvement in neonates with perinatal asphyxia not only complicates perinatal management but also contributes to increased mortality.

AIM

To assess cardiac troponin T (cTnT) levels in asphyxiated neonates and their correlation with echocardiography findings, inotrope requirement, hypoxic-ischemic encephalopathy (HIE) stages, and mortality.

METHODS

cTnT levels, echocardiographic findings, the requirement of inotropes, HIE stages, and outcome were studied in neonates of gestational age ≥ 34 wk with perinatal asphyxia.

RESULTS

Among 57 neonates with perinatal asphyxia, male gender, cesarean section, forceps/vacuum-assisted vaginal delivery and late preterm included 33 (57.9%), 23 (40.4%), 3 (5.3%), and 12 (21.1%) respectively. The mean gestational age was 38.4 wk (1.6 wk). HIE stages I, II, and III were observed in 7 (12.3%), 37 (64.9%), and 9 (15.8%) neonates respectively. 26 (45.6%) neonates had echocardiographic changes and 19 (33.3%) required inotropes. cTnT levels were elevated in 41 (71.9%) neonates [median (IQR); 0.285 (0.211-0.422) ng/mL]. The Median cTnT level showed an increasing trend with increasing changes in echocardiography (P = 0.002). Two neonates with mitral regurgitation and global hypokinesia had the highest cTnT levels (1.99 and 0.651 ng/mL). Of 31 neonates with normal echocardiography, 18 (58.06%) showed elevated cTnT. cTnT levels were significantly higher in those who required inotropic support than those who did not (P = 0.007). Neonates with HIE stage III had significantly higher cTnT levels compared to those with HIE stage I/II (P = 0.013). Survivors had lower median cTnT levels [0.210 (0.122-0.316) ng/mL] than who succumbed [0.597 (0.356-1.146) ng/mL].

CONCLUSION

cTnT levels suggestive of cardiac involvement were observed in 71.9% of asphyxiated neonates. cTnT levels correlated with echocardiography findings, inotrope requirement, HIE stages, and mortality.

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.

Troponin T correlates with MRI results in neonatal encephalopathy

AIM

Troponin is a sensitive marker of asphyxia in term infants mirroring the myocardial injury sustained in global hypoxia-ischaemia. In addition, troponin is a sensitive marker of severity of stroke in adults and neonatal encephalopathy (NE). We aimed to examine the relationship between troponin T in infants with perinatal asphyxia and brain injury on MRI and correlate with neurodevelopmental outcome.

METHODS

Serum troponin was sampled in infants requiring resuscitation at birth and/or neonatal encephalopathy in a tertiary referral neonatal centre. Birth history, clinical parameters, neuroimaging and developmental outcome (Bayley Scores of Infant Development [BSID] III) were evaluated.

RESULTS

Infants with perinatal asphyxia (n = 54) had serum troponin T measured and 27 required therapeutic hypothermia. Troponin T levels on days 1 and 2 were predictive of need for TH, development of seizures and grade II/III NE (AUC = 0.7; P-values < .001), troponin T levels on days 1, 2 and 3 were highly significant predictors of mortality (AUC = 0.99, P-values .005). The cut-off values of troponin T for best prediction of mortality were 0.84, 0.63 and 0.58 ng/mL on days 1, 2 and 3, respectively. Troponin T on day 3 of life was predictive of injury in the combined area of basal ganglia/watershed on MRI (AUC 0.70; P-value = .045).

CONCLUSION

Infants with brain injury on neuroimaging following perinatal asphyxia had significantly elevated serum troponin, and troponin also correlated with developmental scores at 2 years. Further studies combining troponin and MRI may assist in the classification of neonatal brain injury to define aetiology, prognosis and response to treatment.

Management of Multi Organ Dysfunction in Neonatal Encephalopathy

Neonatal Encephalopathy (NE) describes neonates with disturbed neurological function in the first post-natal days of life. NE is an overall term that does not specify the etiology of the encephalopathy although it often involves hypoxia-ischaemia. In NE, although neurological dysfunction is part of the injury and is most predictive of long-term outcome, these infants may also have multiorgan injury and compromise, which further contribute to neurological impairment and long-term morbidities. Therapeutic hypothermia (TH) is the standard of care for moderate to severe NE. Infants with NE may have co-existing immune, respiratory, endocrine, renal, hepatic, and cardiac dysfunction that require individualized management and can be impacted by TH. Non-neurological organ dysfunction not only has a negative effect on long term outcome but may also influence the efficacy of treatments in the acute phase. Post resuscitative care involves stabilization and decisions regarding TH and management of multi-organ dysfunction. This management includes detailed neurological assessment, cardio-respiratory stabilization, glycaemic and fluid control, sepsis evaluation and antibiotics, seizure identification, and monitoring and responding to biochemical and coagulation derangements. The emergence of new biomarkers of specific organ injury may have predictive value and improve the definition of organ injury and prognosis. Further evidence-based research is needed to optimize management of NE, prevent further organ dysfunction and reduce neurodevelopmental impairment.

Myocardial dysfunction as a predictor of the severity and mortality of hypoxic ischaemic encephalopathy in severe perinatal asphyxia: a case-control study

Background: In perinatal asphyxia, hypoxia often leads to myocardial ischaemia. Few studies have assessed the degree of myocardial dysfunction in severely asphyxiated term neonates. Aim: To assess the extent of myocardial damage in newborns with severe perinatal asphyxia. Methods: A case-control study was conducted in asphyxiated newborns with hypoxic ischaemic encephalopathy (HIE) and in controls who were term non-asphyxiated newborns. Total (T) creatinine kinase (CK), CK-MB, troponin-T and 12-lead electrocardiography (ECG) and echocardiography were performed in both groups within 24-48 h after birth. The proportions of asphyxiated neonates with myocardial dysfunction and its relationship between severity of HIE and immediate outcome was compared. Results: Five of 23 asphyxiated neonates developed stage I, 10 stage II and eight stage III HIE. Serum levels of CK-T and CK-MB were raised in all 23 cases and troponin-T was raised in 13 (56.5%) HIE cases. ECG was abnormal in all cases and echocardiography in three (13%). Left ventricular ejection fraction (LVEF) and right ventricular ejection fraction (RVEF) were significantly decreased in all asphyxiated neonates. Eight (35%) patients died. Enzyme levels were higher and ECG and echocardiography abnormalities were common in infants with more severe HIE (p <0.05). Mean serum levels of CK-T and MB (p <0.001) and troponin-T (p =0.002) were higher in non-survivors. Mean LVEF and RVEF values were higher in survivors (p <0.001). All the controls had normal enzyme levels and echocardiography. ECG was abnormal in one control. Conclusion: Cardiac enzymes, ECG and echocardiography changes were associated with increasing severity of HIE and mortality.

Cardiac Troponin T in Healthy Full-Term Infants

In this prospective cohort study of healthy full-term infants, we hypothesized that high-sensitivity cardiac troponin T (hs-cTnT) would be elevated in cord blood, compared with adult reference values, and that it would further increase over the first days of age. Cardiac troponin T has been shown to be significantly increased in healthy full-term newborns compared with adult reference values, but there is no established reference range. Most studies of cTnT in newborns have been performed before the introduction of high-sensitivity cTnT (hs-cTnT) assay. We conducted a study including 158 full-term newborns, at Stockholm South General Hospital. High-sensitivity cTnT was analyzed in umbilical cord blood and at 2-5 days of age. Median hs-cTnT (interquartile range) in cord blood was 34(26-44) ng/L; 99th percentile 88 ng/L. Median hs-cTnT at 2-5 days of age was 92(54-158) ng/L; 99th percentile 664 ng/L. We conclude that hs-cTnT is elevated in cord blood in healthy, full-term newborn infants compared with adult reference values, and that it increases significantly during the first days of life. Our findings further underline the need of caution when using hs-cTnT as a measurement of cardiac impact in newborns.

Cardiac Troponin-T as a Marker of Myocardial Dysfunction in Term Neonates with Perinatal Asphyxia

OBJECTIVES

To describe the diagnostic test properties of Cardiac Troponin-T (cTnT) in predicting myocardial dysfunction in asphyxiated term neonates by taking echocardiography as the gold standard and to establish the optimum cut-off values of cTnT for myocardial dysfunction, shock, severe hypoxic ischemic encephalopathy (HIE) and mortality by receiver operator characteristic (ROC) curve analysis.

METHODS

This was a prospective study based on diagnostic test evaluation. The study included 120 term asphyxiated neonates in a tertiary care neonatal intensive care unit (NICU) in Southern India from June 2011 through June 2015. All the neonates were clinically evaluated. Venous blood was taken at 4 h of life for cTnT estimation. Echocardiography was done within 24 h of birth.

RESULTS

The mean cTnT level of asphyxiated term neonates was 0.207±0.289 ng/ml (mean ± SD). Asphyxiated neonates with myocardial dysfunction had higher cTnT levels (0.277±0.231) as compared to those without myocardial dysfunction (0.061±0.036, p = 0.0001). Using ROC curve, the cut-off cTnT values for myocardial dysfunction was 0.1145 ng/ml with sensitivity 92.4% and specificity 94.1%. Cardiac Troponin-T levels were significantly higher among asphyxiated neonates with shock (0.378±0.348, p = 0.0001) and the levels also correlated positively with increasing grades of HIE. The cut-off cTnT value for mortality was 0.2505 ng/ml with sensitivity 83.9% and specificity 96.6%.

CONCLUSIONS

In asphyxiated term neonates, early cTnT elevation is a marker for predicting myocardial dysfunction and elevated cTnT levels had high sensitivity and specificity. There was significant relation with increasing cTnT values and increasing grades of HIE.

Early survival following in utero myocardial infarction

Intrauterine myocardial infarction is a rare and frequently fatal diagnosis. It has been presented in the literature only as case reports and short series. We present a case report of a coronary occlusive intrauterine myocardial infarction and survival and present a systematic review of the literature. This is the first summative description of current data on intrauterine and perinatal myocardial infarction. We performed the systematic review based on the guidelines established by the PRISMA statement. Our population of intrauterine and perinatal myocardial infarction included published cases who presented as a live birth within the first 28 postnatal days, and had a diagnosis of myocardial infarction. We conducted descriptive statistics and regression analysis on short-term mortality as the primary outcome. After applying exclusion criteria we described 84 individual cases of myocardial infarction from 63 full-text articles including our own case. Presentation within the first 12 hours was associated with mortality (OR 3.90, p=0.004). Treatment modalities were varied and inconsistently recorded. The aetiologies and comorbidities are varied in our systematic review. We would have a low threshold to perform viral testing, consider anticoagulation early and coronary imaging if feasible. The use of extracorporeal membranous oxygenation may serve as a bridge to cardiac recovery.

Troponin-T as a biomarker in neonates with perinatal asphyxia

BACKGROUND

Troponin-T is a commonly used cardiac biomarker, which could be useful in perinatal asphyxia. We aimed to analyze troponin-T concentrations in asphyxiated neonates and to correlate the concentrations with clinical outcomes.

METHODS

Data were collected from electronic medical records of neonates diagnosed with perinatal asphyxia over a period of four years.

RESULTS

There were 63 neonates with moderate to severe encephalopathy, in whom serial troponin-T concentrations had been done on days 1, 3, and 7. 53 (84%) asphyxiated infants had troponin-T concentration >100 pg/ml at 2-4 h of life.The difference in troponin-T concentrations between moderate and severe encephalopathy was not statistically significant (173 vs. 263 pg/ml, p value 0.40). The difference in the concentrations at 72 hours between cooled and non-cooled neonates was not significant (48.5 vs. 62.5 pg/ml, p value 0.22). Troponin-T concentration was significantly higher in babies with hypotensive shock and hepatic injury, but not acute kidney injury. There was no significant correlation between troponin-T and the extent of resuscitation needed.Troponin-T concentration on day 1 of life was significantly higher in babies who died than who survived (407 vs. 168 pg/ml, p value 0.03). ROC curve for troponin-T to predict mortality had an area under the curve (AUC) of 0.803; the best cut-off value (190 pg/ml) had 82% sensitivity and 80% specificity.

CONCLUSION

There was no significant difference in troponin-T concentrations between cooled and non-cooled neonates. Troponin-T concentration had a good predictive accuracy for mortality before discharge.

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.

The Evaluation of Cardiac Troponin T in Newborns

Introduction

In this paper, we evaluated the physiologic ranges of cardiac troponin T (cTnT) serum concentrations in healthy newborns. This is significant because these ranges have not been determined yet, especially for newborns older than 7 days. Cardiac troponins are widely used as diagnostic markers in adults; however, they cannot be routinely used in infants due to lack of data concerning normal values in this age group.

Aim

To determine the physiologic ranges of cTnT concentrations in newborns and to evaluate the influence of factors such as age, sex, and blood saturation.

Methods

The study involved 59 newborns up to 46 weeks of postmenstrual age (full-term and preterm). The exclusion criteria were severe perinatal asphyxia and presence of severe diseases. Troponin T concentrations were evaluated by the Roche CARDIAC T Quantitative Test. The obtained results were statistically analyzed by the use of the Statistica 9.0 computer program.

Results

The study revealed that cTnT levels in newborns correlate with postmenstrual age, but not with chronologic or fetal age. Sex, delivery mode, and blood oxygenation did not influence cTnT concentrations in the studied patients.

Conclusions

(1) Cardiac troponin T concentration depends on postmenstrual age in newborns. (2) Cardiac troponin T concentration in newborns does not depend on sex, mode of delivery, or blood saturation.

Management and investigation of neonatal encephalopathy: 2017 update

This review discusses an approach to determining the cause of neonatal encephalopathy, as well as current evidence on resuscitation and subsequent management of hypoxic-ischaemic encephalopathy (HIE). Encephalopathy in neonates can be due to varied aetiologies in addition to hypoxic-ischaemia. A combination of careful history, examination and the judicious use of investigations can help determine the cause. Over the last 7 years, infants with moderate to severe HIE have benefited from the introduction of routine therapeutic hypothermia; the number needed to treat for an additional beneficial outcome is 7 (95% CI 5 to 10). More recent research has focused on optimal resuscitation practices for babies with cardiorespiratory depression, such as delayed cord clamping after establishment of ventilation and resuscitation in air. Around a quarter of infants with asystole at 10 min after birth who are subsequently cooled have normal outcomes, suggesting that individualised decision making on stopping resuscitation is needed, based on access to intensive treatment unit and early cooling. The full benefit of cooling appears to have been exploited in our current treatment protocols of 72 hours at 33.5°C; deeper and longer cooling showed adverse outcome. The challenge over the next 5-10 years will be to assess which adjunct therapies are safe and optimise hypothermic brain protection in phase I and phase II trials. Optimal care may require tailoring treatments according to gender, genetic risk, injury severity and inflammatory status.

The Severity of Hypoxic-Ischemic Encephalopathy Correlates With Multiple Organ Dysfunction in the Hypothermia Era

OBJECTIVES

The objectives are to 1) determine whether there is a positive correlation between the severity of hypoxic-ischemic encephalopathy and multiple organ dysfunction and 2) evaluate the organ dysfunction pattern in infants with hypoxic-ischemic encephalopathy in the hypothermia era.

DESIGN

Retrospective observational study of prospective data collected between April 2009 and December 2012.

SETTING

The study took place in the neonatal ICU of Hospital Sant Joan de Déu-Hospital Clínic of Barcelona.

PATIENTS

Prospective consecutive newborns with greater than or equal to 36 weeks of gestation, greater than or equal to 1,800 g of weight at birth, and a diagnosis of hypoxic-ischemic encephalopathy was included.

INTERVENTIONS

Severity of hypoxic-ischemic encephalopathy was established before starting controlled hypothermia. Six organ systems and 23 clinical and laboratory variables were studied by means of an asymmetrical grading scale. Data were recorded daily during the first 72 hours of life.

MEASUREMENTS AND MAIN RESULTS

Seventy-nine patients were studied. All presented with multiple organ dysfunction on day 1. There were differences in the number of affected organs on day 1 according to hypoxic-ischemic encephalopathy stage (p < 0.001). Scale scores correlated positively with the severity of hypoxic-ischemic encephalopathy (area under the curve ranged from 0.77 to 0.87 on every day studied). There were significant differences in the severity of dysfunction of each organ system among the three hypoxic-ischemic encephalopathy stages (p < 0.05). Although the most frequently involved were hepatic and pH and electrolyte imbalance, the most severely affected were the respiratory and cardiovascular systems.

CONCLUSIONS

In the hypothermia era, multiple organ dysfunction continues to be almost universal in newborns with hypoxic-ischemic encephalopathy. There is a high correlation between the severity of hypoxic-ischemic encephalopathy and multiple organ dysfunction during the first 3 days of life. A high index of suspicion of relevant multiple organ dysfunction is required in infants admitted with a diagnosis of severe hypoxic-ischemic encephalopathy. Patients with moderate hypoxic-ischemic encephalopathy present wide variability in the severity of multiple organ dysfunction. In the absence of multiple organ dysfunction, a perinatal hypoxic-ischemic origin of acute severe neonatal encephalopathy should be carefully reconsidered.

The Diagnostic Value of Troponin T Level in the Determination of Cardiac Damage in Perinatal Asphyxia Newborns

Perinatal asphyxia is a clinical condition which results from oxygen deprivation of the fetus or newborn and the breakdown of perfusion in various organs. The aim of this study was to evaluate and compare troponin T levels over time as a marker of cardiac injury in cases of perinatal asphyxia and healthy newborns. The study included a total of 30 newborns diagnosed with perinatal asphyxia with a gestational age of 32-41 weeks, based on the last menstruation date, and 30 healthy newborns with a gestational age of 34-40 weeks, as the control group. Levels of troponin T and creatinin kinase MB were recorded for all participants. No difference was determined between the groups in terms of gestational age, manner of birth, electrocardiographic findings, and PaO2 and PaCO2 values. The umbilical artery pH levels and bicarbonate levels in the study group were found to be statistically lower than those in the control group (p < 0.001). The troponin T and creatinin kinase MB levels in the patients in the study group were higher than those within the control group, at all times. The periods when specificity and sensitivity were highest together for troponin T were the 12th and 24th h. Specificity for troponin T reached the highest value at the 24th h and sensitivity reached the highest value in the cord blood. A positive correlation was found between the troponin T and creatinin kinase MB values at the 6th and 12th h. However, no correlation could be found in the blood between the serum troponin T and creatinin kinase MB levels at the 3rd and 24th h. The troponin T level is a useful test for showing cardiac damage in hypoxic patients in the neonatal period. The sensitivity and specificity of cardiac specific troponin T levels in detecting cardiac damage are much higher according to telecardiography and electrocardiography, while the implementation of the method is simple.

Troponin T and NT ProBNP Levels in Gestational, Type 1 and Type 2 Diabetic Mothers and Macrosomic Infants

This study compares NT proBNP and troponin T levels in umbilical cord arterial blood and postnatal echocardiographic findings for infants of gestational and pregestational diabetic mothers and macrosomic infants. Twenty-seven infants of pregestational diabetic mothers, 61 infants of gestational diabetic mothers and 37 macrosomic infants of nondiabetic mothers were prospectively enrolled in this study along with a control group of 58 healthy infants of mothers without any pregestational or gestational disorders as the control group. All enrollees were born after 34 weeks of gestation. For this study, umbilical cord blood was drawn during delivery to determine NT proBNP and troponin T levels. Echocardiography was performed 24-72 h after the delivery. Umbilical cord troponin T and NT proBNP levels were found to be higher in the diabetic and macrosomic groups than in the control group (all of them p < 0.001). NT proBNP levels were positively correlated with interventricular septum thickness in the pregestational and gestational infants of diabetic mothers groups (r = 0.564 and r = 0.560, respectively, p < 0.01). Both pregestational and gestational diabetic mothers were divided into two groups according to HbA1c levels in the third trimester as good (<6.1 %) and suboptimal (>6.1 %) metabolic control. In the good and suboptimal metabolic control diabetic groups, NT proBNP levels were also positively correlated with interventricular septum thickness (r = 0.536 and r = 0.576, respectively, p < 0.01). In the suboptimal metabolic control diabetic group, NT proBNP was only found to be positively correlated with the left ventricular mass index (r = 0.586, p < 0.01). While there was no correlation in the myocardial performance index between infants of diabetic mothers and the control group, the myocardial performance index of macrosomic infants was lower than that of the control group (p = 0.017). Cardiac biomarkers (NT proBNP and troponin T) were elevated in infants of diabetic mothers and macrosomic infants. While there was a positive correlation between NT proBNP levels and cardiac structure in infants of pregestational and gestational diabetic mothers, there was no relationship between NT proBNP levels and cardiac function.

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.

Salivary lactate dehydrogenase levels can provide early diagnosis of hypoxic-ischaemic encephalopathy in neonates with birth asphyxia

AIM

Timely detection of hypoxic-ischaemic encephalopathy (HIE) is crucial for selecting neonates who are likely to benefit from neuroprotective therapy. This study evaluated the efficacy of salivary lactate dehydrogenase (LDH) in the early diagnosis of HIE among neonates with perinatal asphyxia.

METHODS

We prospectively enrolled 30 neonates who needed resuscitation at birth or had a history of delayed cry into the HIE group if they developed HIE within 12 h of birth. The control group comprised 30 neonates who had no evidence of HIE, but had intrapartum foetal distress or needed resuscitation at birth. LDH was measured using saliva samples collected within 12 h of birth.

RESULTS

Salivary LDH was significantly higher in the HIE group, with a median of 2578 and an interquartile range (IQR) of 1379-3408 international units per litre (IU/L), than in the control group (median 558.5, IQR: 348-924 IU/L, p < 0.001). The test demonstrated excellent discriminating ability: the area under the curve was 0.92 and the levels of 893 IU/L showed a sensitivity of 90% and a specificity of 73.3%.

CONCLUSION

Measuring salivary LDH among neonates with birth asphyxia provided an early and accurate diagnosis of HIE and could be used as a triage tool.

Metabolomics applied in neonatology

Over the past two decades, host-response biomarkers have been extensively used by clinicians for a better understanding of normal biological processes, the complexity and severity of illnesses, or pharmacological responses to therapeutic intervention. A myriad of information can be drawn from the gender, age, dietary intake and the disease history of an individual. These biomarkers may be promising for the complete phenotyping of a cell, tissue or an organism. In neonatology, these molecular markers may help in prediction of disease severity and its outcome, thus allowing personalized interventions. In this Review, existing data in the literature on metabolites in plasma, urine and maternal milk that may offer a unique insight into the host's dynamic behavior in different neonatal conditions will be examined.

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.

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.

Serum cardiac troponin T in asphyxiated term neonates delivered at two teaching hospitals in lagos, Nigeria

BACKGROUND

Asphyxia is a leading cause of perinatal morbidity and mortality in the developing countries. All organs including the myocardium are vulnerable to ischemic injury in asphyxia. The aim of the current study was to assess myocardial injury in asphyxiated full-term neonates using their serum cardiac troponin T levels.

METHODS

In all, 30 term asphyxiated neonates and 30 gestational age-, birth weight-, and sex-matched controls were studied. Asphyxia was defined by double criteria of low umbilical arterial blood pH <7.20 and low five-minutes Apgar score ≤6, while the controls were term nonasphyxiated neonates with umbilical arterial blood pH ≥7.20 and five minutes Apgar score >6. The umbilical arterial pH was done soon after delivery, while the serum cardiac troponin T was done within the first 4 to 24 hours of life.

RESULTS

Participants and controls were similar in terms of mean gestational age, mode of delivery, gender, and birth weight (P = 1.0, .07, 1.0, and 1.0, respectively). Two thirds of the asphyxiated babies had elevated serum cardiac troponin T in the high risk range (> 0.1 ng/mL). On the contrary, none of the controls had serum cardiac troponin T in that range. Serum cardiac troponin T showed negative correlation with pH (r = -.75), five-minute Apgar score (r = -.74), and one-minute Apgar score (r = -0.70).

CONCLUSION

The study identified perinatal asphyxia as a high-risk factor for elevated serum cardiac troponin T and hence for myocardial cellular injury.

Cardiac biomarkers in neonatal hypoxic ischaemia

Following a perinatal hypoxic-ischaemic insult, term infants commonly develop cardiovascular dysfunction. Troponin-T, troponin-I and brain natriuretic peptide are sensitive indicators of myocardial compromise. The long-term effects of cardiovascular dysfunction on neurodevelopmental outcome following perinatal hypoxic ischaemia remain controversial. Follow-up studies are warranted to ensure optimal cardiac function in adulthood.

CONCLUSION

Cardiac biomarkers may improve the diagnosis of myocardial injury, help guide management, estimate mortality risk and may also aid in longterm neurodevelopmental outcome prediction following neonatal hypoxic-ischaemia.

Cardiac troponin T as a marker of myocardial injury in a group of asphyxiated African neonates

BACKGROUND

In caucasian newborns, troponin T (cTnT) is a specific marker for myocardial injury in perinatal asphyxia. This is the first such study in negroid neonates.

AIMS

To evaluate myocardial injury in a group of asphyxiated African newborns and determine the influence of mode of delivery on cTnT levels.

METHODS

Serum cTnT and clinical parameters in 40 asphyxiated and 40 healthy negroid neonatal controls were measured within the first 72 hours of life by chemiluminescence immune-assay. Perinatal asphyxia was assessed by APGAR score. The infants were followed up until discharge or death.

RESULTS

Mean (SD) cTnT values were significantly higher in asphyxiated infants [0.03 (0.04) ng/ml] than in healthy controls [0.01 (0.006) ng/ml, P = 0.002]. Asphyxiated infants delivered by forceps and vacuum extraction had significantly higher levels of cTnT [0.04 (0.018) ng/ml] than those born by caesarian section [0.02 (0.008) ng/ml] and by normal delivery [0.03 (0.01) ng/ml, P = 0.003]. cTnT levels were higher in infants who died (P = 0.037).

CONCLUSION

In the asphyxiated infants, mean cTnT levels were significantly higher than in controls. They were also significantly higher in those born by vacuum and forceps delivery and asphyxiated infants who died.

Biomarkers in neonatology: the next generation of tests

Over the past two decades, neonatal clinicians have commonly used host response biomarkers to diagnose and assess the severity of systemic infection. Most of these biomarkers, such as acute-phase proteins or cytokines, are non-specific immunomodulating mediators of the inflammatory cascade. With advances in biochemical/genetic research, it is anticipated that future biomarkers will be 'organ and/or disease specific'. There is also the quest for discovery of 'novel' biomarkers to assist diagnosis and prognosis of neonatal diseases using powerful mass-screening techniques, e.g. the next-generation sequencing, proteomics and arrays. This article aims to introduce the concept of the next generation of biomarkers to practising neonatal clinicians, and, hopefully, to integrate basic science research into day-to-day clinical practice in the future.

Cardiac troponin I concentrations in neonates with hypoxic-ischaemic encephalopathy

AIM

Myocardial dysfunction is a frequent sequel of perinatal asphyxia. Cardiac troponin I (cTnI) is a marker of myocardial injury and a surrogate marker of myocardial dysfunction in adults, but there are few data in neonates. Our aim was to compare serum cTnI concentrations with clinical severity of encephalopathy and with duration of inotropic support in asphyxiated neonates.

METHODS

Retrospective study of 60 neonates admitted with hypoxic-ischaemic encephalopathy (HIE). cTnI concentrations measured within 36 h of birth were compared with clinical grade of HIE (Sarnat-Sarnat classification) and with duration of inotropic support.

RESULTS

Serum cTnI concentrations and duration of inotropic support were significantly greater with increasing severity of HIE. Median (95% CI) cTnI concentrations were 0.04 μg/L (0.02-0.07 μg/L) in grade 1 HIE, 0.12 μg/L (0.08-0.20 μg/L) in grade 2 HIE and 0.67 μg/L (0.41-1.35 μg/L) in grade 3 HIE. Median (95% CI) duration of inotropic support required was 0 h (0-24 h) in grade 1 HIE, 28 h (0-118 h) in grade 2 HIE and 48 h (0-140 h) in grade 3 HIE.

CONCLUSION

In asphyxiated neonates, cTnI concentrations within 36 h of birth correlate strongly with clinical grade of HIE and with duration of inotropic support. Early cTnI concentrations may provide a useful proxy marker for the anticipated severity of myocardial dysfunction.

The relation between delivery type and cord blood levels of chitotriosidase and Troponin T

The operative deliveries can expose the fetus to acute and systemic hypoxia along with an increase in perinatal morbidity. The aim of this study was to reveal any relationship between delivery type and Chitotriosidase and Troponin T levels in cord blood. Ninety babies born in Ankara Etlik Maternity and Women’s Health Teaching Hospital were involved in the study. The babies were divided into three groups; Group 1: Normal vaginal; Group 2: Caesarean section; Group 3: Forceps application. Cord blood samples were drawn from umbilical arteries of the babies soon after the birth. Chitotriosidase enzyme activities in group 3 (141 nmol/ml/h (0–246)) were found higher than groups 1 (100 nmol/ml/h (0–208)) and 2 (91 nmol/ml/h (0–202)) (p<0.01 and p<0.03 respectively). Although cardiac Troponin T levels were higher in group 3, the difference among groups was not statistically significant (p=0.79). Acute or systemic hypoxic exposure of the organism gives rise to a microvascular response characterized by interactions between leukocytes and endothelium. We are hypothesizing that the high levels of chitotriosidase found in the forceps group were due to hypoxia, and that chitotriosidase level can be used as a marker of acute and systemic hypoxia.

Myocardial performance in asphyxiated full-term infants assessed by Doppler tissue imaging

The aim of this study was to assess myocardial performance of full-term infants with perinatal asphyxia using Doppler tissue imaging (DTI) and to correlate it with serum cardiac troponin T (cTnT) concentrations. Twenty-five asphyxiated and 20 nonasphyxiated term infants were investigated. Serum cTnT concentrations were measured between 12 and 24 h of life. Conventional two-dimensional Doppler echocardiography and DTI were done during the first 72 h of life. Right ventricular (RV) and left ventricular (LV) Tei indexes were significantly higher in asphyxiated neonates (mean +/- SD: 0.45 +/- 0.05 vs. 0.28 +/- 0.05, P < 0.001 and 0.51 +/- 0.04 vs. 0.38 +/- 0.04, P < 0.001, respectively). Mitral and tricuspid systolic (Sm) velocities were significantly lower in asphyxiated neonates (mean +/- SD: 5.06 +/- 0.89 vs. 6.89 +/- 0.94 cm/s, P < 0.001 and 5.78 +/- 0.58 vs. 6.69 +/- 0.87 cm/s, P < 0.001, respectively). cTnT concentrations were significantly higher in asphyxiated neonates [median (range): 0.17 (0.05-0.23) vs. 0.03 (0-0.07) microg/l, P < 0.001)], and they correlated positively with the LV Tei index (r = 0.67, P < 0.001) and the RV Tei index (r = 0.68, P < 0.001) and negatively with the mitral systolic (Sm) velocity (r = -0.68, P < 0.001) and tricuspid systolic (Sm) velocity (r = -0.41, P = 0.01). A higher cTnT was a significant predictor of mortality, whereas fractional shortening (FS) and DTI measurements did not show any significant predictive value. The DTI technique appears to be more sensitive than conventional echocardiography in the early detection of myocardial dysfunction induced by perinatal asphyxia in full-term infants.

Staphylococcus aureus Septicemia with a fatal transmural myocardial infarction in a 27-week-gestation twin infant: a case study

Septicemia, one of the major causes of morbidity and mortality in the neonatal period, often has a rapid and fulminant course. Low-birth-weight infants with persistent Staphylococcus aureus septicemia, possibly associated with percutaneous central venous catheters, may develop metastatic infections including endocarditis with large vegetations. This article describes a neonate with S. aureus bacteremia that resolved with treatment who died secondary to decreased left ventricular function. At autopsy, organizing microthrombi were seen within both atria, the left ventricle, and the left coronary arterial system. Extensive infarcts were noted throughout the entire myocardium of the left ventricle. It was suspected, but not proven, that the thrombotic sequelae from septicemia caused this neonate's death.

Serum troponin in neonatal intensive care

Cardiac troponins have a major role in screening and diagnosis of myocardial ischaemia in adults and children. Their introduction has redefined the diagnosis of myocardial infarction in adults and provided valuable prognostic information. In the paediatric population, troponins show a good correlation with the extent of myocardial damage following cardiac surgery and cardiotoxic medication, and can be used as predictors of subsequent cardiac recovery and mortality. This review discusses the current established reference values in term and preterm infants and demonstrates their potential use in neonatology. They may serve as a useful adjunct in the assessment of the magnitude of myocardial injury in respiratory distress syndrome and asphyxia. They may also benefit centres without on-site echocardiography with some evidence showing good correlation with echo-derived markers of myocardial function. The use of troponins in the neonatal unit remains a research tool. More work is needed to explore their prognostic role and monitoring response to treatment following cardioprotective strategies. In preterm infants the effect of inotropes on myocardial function needs further study and troponin may form an integral part of this research.

Myocardial injury in infants ventilated on the paediatric intensive care unit: a case control study

Introduction

Cardiac troponin T (cTnT) has been used to assess prevalence of myocardial injury in critically ill children. The majority of studies investigated patients undergoing cardiac surgery. Myocardial injury has been associated with increased mortality. Our objectives were to investigate whether cTnT levels are elevated in infants without congenital heart disease admitted to the paediatric intensive care unit (PICU) and whether levels are associated with increased disease severity.

Methods

We measured cTnT in consecutive infants (<12 months old) without congenital heart disease admitted to the PICU and healthy infants. The Paediatric Index of Mortality (PIM) score was determined in patients on the PICU.

Results

We recruited 107 infants: 47 infants admitted to the PICU and 60 healthy controls. Controls were, with a median (interquartile range (IQR)) age of 20 (12 to 34) weeks, significantly older than cases, with a median age of 6.5 (0.3 to 20.6) weeks. CTnT levels were, with a median (IQR) of 18 (10 to 60) pg/ml, significantly higher in admissions to the PICU than in controls, with a median level of 10 (10 to 10) pg/ml (95th centile of 20 pg/ml) (p < 0.001). There was a significant positive correlation (r = 0.41, p = 0.004) between PIM score and cTnT levels. Admissions under one month old had higher cTnT levels than older patients (p = 0.013) but the PIM score was not significantly different between them. When corrected for age and weight the correlation of PIM and cTnT was no longer significant.

Conclusion

Infants on the PICU in the neonatal period have higher cTnT levels compared to older infants despite not having more severe disease.