Cardiovascular Biomarkers in Amniotic Fluid, Umbilical Arterial Blood, Umbilical Venous Blood, and Maternal Blood at Delivery, and Their Reference Values for Full-Term, Singleton, Cesarean Deliveries

Copeptin as a diagnostic and prognostic biomarker in pediatric diseases

Arginine vasopressin (AVP) plays a main role in maintaining the homeostasis of fluid balance and vascular tone and in regulating the endocrine stress response in response to osmotic, hemodynamic and stress stimuli. However, the difficulty in measuring AVP limits its clinical application. Copeptin, the C-terminal part of the AVP precursor, is released in an equimolar concentration mode with AVP from the pituitary but is more stable and simple to measure. Therefore, copeptin has emerged as a promising surrogate marker of AVP with excellent potential for the diagnosis, differentiation and prognosis of various diseases in recent decades. However, its application requires further validation, especially in the pediatric population. This review focuses on the clinical value of copeptin in different pediatric diseases and the prospects for its application as a potential biomarker.

Fetal cardiac troponin I levels decline toward birth in sheep

Elevated cardiac troponin I (cTnI), a myocardial damage biomarker, has been reported in cord blood of neonates delivered vaginally or by cesarean section. Although the neonatal peak likely reflects the physiological adjustment to extrauterine life, a better understanding of serial prepartum changes is required to determine physiological causes of fetal cTnI release. We longitudinally sampled eight healthy lambs (20 days before spontaneous birth to 5 days postnatal), and from three fetuses receiving intravenous IGF-1. Samples were collected into heparin, and the plasma was stored at -80°C for later determination of high-sensitivity (hs) cTnI levels (BeckmanCoulter UniCel DxI Access IA; log transformed detection limit = 0.30, quantification limit = 0.78, 99th percentile = 1.78). Positive and negative control samples were drawn from an adult ewe during a terminal experiment (myocardial ischemia) and similarly assessed. hs-cTnI data were log transformed from ng/L. Log(hs-cTnI) was 1.47 ± 0.30 (means ± SD) at 20 days before birth and declined to 1.02 ± 0.65 in fetuses 12 ± 4 h before birth (P < 0.0001, R2 = 0.7869). Birth stimulated a delayed, transient peak in hs-cTnI (P = 0.0058). Newborn (43 ± 19 min postnatal) levels were 1.39 ± 0.40 (P = 0.0650 vs. fetus on day of birth) and 2.14 ± 0.63 the day after birth (P = 0.0331 vs. newborn). The second day after birth, levels declined to 1.65 ± 0.48 (P = 0.0238 vs. day 1). IGF-1 infusion increased hs-cTnI levels 25-50% over baseline (P = 0.0252, R2 = 0.9938). Baseline adult ewe log(hs-cTnI) was below the limit of detection; 3 h following coronary artery ligation, levels were 3.21. In conclusion, we newly report that fetal hs-cTnI levels decline concomitantly with reduced proliferation of cardiomyocytes toward term.NEW & NOTEWORTHY Serial blood samples were collected from catheterized, normally developing fetal and newborn lambs and high-sensitivity cardiac troponin I (hs-cTnI) levels were assessed, providing unprecedented insight into the physiological processes leading to high levels in the perinatal period. Moderately high levels of hs-cTnI found in the normally developing fetus declined toward term. An elevation to high levels peaked the day after birth, after which hs-cTnI declined again. Stimulation of fetal cardiomyocyte proliferation with IGF-1 also elevated hs-cTnI.

Intra-amniotic infection and/or inflammation is associated with fetal cardiac concentric hypertrophy and diastolic dysfunction in preterm labor and preterm prelabor rupture of membranes

BACKGROUND

Preterm delivery is associated with cardiovascular remodeling and dysfunction in children and adults. However, it is unknown whether these effects are caused by the neonatal consequences of preterm birth or if these are already present in utero.

OBJECTIVE

We evaluated fetal cardiac morphology and function in fetuses of mothers admitted for preterm labor or preterm prelabor rupture of membranes and the association of these changes with the presence of intra-amniotic infection and/or inflammation.

STUDY DESIGN

In this prospective cohort study, fetal echocardiography and amniocentesis were performed at admission in singleton pregnant women with preterm labor and/or preterm prelabor rupture of membranes between 24.0 and 34.0 weeks' gestation with (intra-amniotic infection and/or inflammation group, n=41) and without intra-amniotic infection and/or inflammation (non-intra-amniotic infection and/or inflammation, n=54). Controls (n=48) were outpatient pregnant women without preterm labor or preterm prelabor rupture of membranes. Intra-amniotic infection was defined by a positive amniotic fluid culture or positive 16S ribosomal RNA gene. Intra-amniotic inflammation was defined by using the amniotic fluid interleukin-6 cutoff levels previously reported by our group being >1.43 ng/mL in preterm prelabor rupture of membranes and >13.4 ng/mL in preterm labor. Fetal cardiac morphology and function was evaluated using echocardiography, and troponin-I and N-terminal pro-brain natriuretic peptide concentrations were measured in amniotic fluid from women with preterm labor or preterm prelabor rupture of membranes and compared with 20 amniotic fluid Biobank samples obtained for reasons other than preterm labor or preterm prelabor rupture of membranes or cardiac pathology. The data were adjusted for the estimated fetal weight below the 10th percentile and for preterm prelabor rupture of membranes at admission and also for gestational age at amniocentesis when amniotic fluid biomarkers were compared.

RESULTS

From 2018 to 2021, 143 fetuses were included; 95 fetuses were from mothers admitted with a diagnosis of preterm labor or preterm prelabor rupture of membranes, and among those, 41 (28.7%) were in the intra-amniotic infection and/or inflammation group and 54 (37.8%) were in the non-intra-amniotic infection and/or inflammation group. A total of 48 (33.6%) fetuses were included in the control group. Fetuses with preterm labor and/or preterm prelabor rupture of membranes had signs of subclinical cardiac concentric hypertrophy (median left wall thickness of 0.93 [interquartile range, 0.72-1.16] in the intra-amniotic infection and/or inflammation group; 0.79 [0.66-0.92] in the non-intra-amniotic infection and/or inflammation group; and 0.69 [0.56-0.83] in controls; P<.001) and diastolic dysfunction (tricuspid A duration 0.23 seconds [0.21-0.25], 0.24 [0.22-0.25], and 0.21 [0.2-0.23]; P=.007). Systolic function was similar among groups. Higher values of amniotic fluid troponin I (1413 pg/mL [927-2334], 1190 [829-1636], and 841 [671-959]; P<.001) and N-terminal pro-brain natriuretic peptide were detected (35.0%, 17%, and 0%; P=.005) in fetuses with preterm labor or preterm prelabor rupture of membranes when compared with the control group. The highest N-terminal pro-brain natriuretic peptide concentrations were found in the intra-amniotic infection and/or inflammation group.

CONCLUSION

Fetuses with preterm labor or preterm prelabor rupture of membranes showed signs of cardiac remodeling and subclinical dysfunction, which were more pronounced in those exposed to intra-amniotic infection and/or inflammation. These findings support that the cardiovascular effects observed in children and adults born preterm have, at least in part, a prenatal origin.

Copeptin: Up-to-date diagnostic and prognostic role highlight

Arginine Vasopressin (AVP) is one of the key hormones in the human body. AVP is clinically important because it maintains body fluid balance and vascular tone. Unfortunately, AVP laboratory measurements are always difficult and with low accuracy. Copeptin, the C-terminal of the AVP precursor, is released in equal amounts with AVP, making it a sensitive marker of AVP release. Despite being a non-specific biomarker, copeptin earned a lot of attention as a novel biomarker due to easy and quick laboratory measurements. Recent studies have reported the critical role of copeptin as a clinical indicator, especially in the diagnosis and prognosis of many diseases. Besides, it was reported that the combination between copeptin and gold standard biomarkers improved the prognostic values of those biomarkers. In this review, the role of copeptin as a new predictive diagnostic and prognostic biomarker of various diseases is highlighted according to the most recent studies. In addition, the importance of using copeptin as a marker in different medical departments and the impact of this on improving healthcare service was discussed.

Biomarkers of cardiovascular disease risk in the neonatal population

The consistently high prevalence of cardiovascular disease (CVD) has urged the need for punctual and effective prevention. Extended research on this specific area has demonstrated the influence of fetal and neonatal periods on the risk of developing CVD in adulthood. Thus, the role of traditional and novel biological markers to the effective screening of CVD among the neonatal population is widely investigated. The objective of the present narrative review is to examine those neonatal biomarkers that may play a role in the development of CVD, to exhibit scientific data that appertain to their association with various perinatal conditions leading to CVD predisposition, and their potential role on prediction and prevention strategies. Multiple biomarkers, traditional and novel, have been mined across the studied literature. Adiposity, insulin resistance, altered lipid profile, inflammation, and endothelial dysfunction seem among the headliners of CVD. Even though various novel molecules have been studied, their clinical utility remains controversial. Therefore, it is quite important for the scientific community to find elements with strong predictive value and practical clinical use.

Comparison of cord blood pro-BNP levels in newborns of SARS-COV-2-positive and -negative women, and its association with adverse perinatal outcomes

OBJECTIVE

To compare umbilical cord blood pro-B-type natriuretic peptide (BNP) levels in newborns of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) positive pregnancies to those of SARS-COV-2 negative pregnancies.

METHODS

Prospectively cord blood samples from newborns of 42 SARS-COV-2 positive women, and 42 negative pregnant were collected at birth and analyzed for pro-BNP levels.

RESULTS

The mean cord blood pro-BNP level was significantly higher in newborns of SARS-COV-2 positive women than in controls. Furthermore, the pro-BNP level was an independent predictor of NİCU admission in both SARS-COV-2 positive and control patients.

CONCLUSION

Cord blood pro-BNP level may be a parameter that can predict the under-stress fetus and adverse perinatal outcomes especially, in cases where placental involvement is present as in SARS-COV-2 infection.

Insights and perspectives into clinical biomarker discovery in pediatric heart failure and congenital heart disease-a narrative review

Background and Objective

Heart failure (HF) in the pediatric population is a multi-factorial process with a wide spectrum of etiologies and clinical manifestations, that are distinct from the adult HF population, with congenital heart disease (CHD) as the most common cause. CHD has high morbidity/mortality with nearly 60% developing HF during the first 12 months of life. Hence, early discovery and diagnosis of CHD in neonates is pivotal. Plasma B-type natriuretic peptide (BNP) is an increasingly popular clinical marker in pediatric HF, however, in contrast to adult HF, it is not yet included in pediatric HF guidelines and there is no standardized reference cut-off value. We explore the current trends and prospects of biomarkers in pediatric HF, including CHD that can aid in diagnosis and management.

Methods

As a narrative review, we will analyze biomarkers with respect to diagnosis and monitoring in specific anatomical types of CHD in the pediatric population considering all English PubMed publications till June 2022.

Key Content and Findings

We present a concise description of our own experience in applying plasma BNP as a clinical biomarker in pediatric HF and CHD (tetralogy of fallot vs. ventricular septal defect) in the context of surgical correction, as well as untargeted metabolomics analyses. In the current age of Information Technology and large data sets we also explored new biomarker discovery using Text Mining of 33M manuscripts currently on PubMed.

Conclusions

(Multi) Omics studies from patient samples as well as Data Mining can be considered for the discovery of potential pediatric HF biomarkers useful in clinical care. Future research should focus on validation and defining evidence-based value limits and reference ranges for specific indications using the most up-to-date assays in parallel to commonly used studies.

Different expressions of cardiac biomarkers between different types of acquired right ventricular outflow tract abnormality in monochorionic twins

OBJECTIVE

To investigate the differences in amniotic fluid cardiac biomarkers and clinical features among types of right ventricular outflow tract (RVOT) abnormality in monochorionic (MC) twins.

METHOD

This prospective study included MC twins that underwent laser surgery. Recipient or larger twins (group A) and donor or smaller twins (group B) were assessed and divided into those with a normal right ventricular outflow tract (normal RVOT), functional pulmonary atresia (fPA), or pulmonary stenosis (PS). Amniotic fluid levels of NT-proBNP (afNT-proBNP) and cardiac troponin T (afTnT) were examined during surgery.

RESULTS

Of 190 fetuses in group A, there were 14 RVOT abnormality cases (including 7 fPA and 7 PS). No group B fetuses showed RVOT abnormality findings. In group A, later and earlier gestational age at surgery were observed in fPA (25.1±2.8 weeks) and PS groups (17.8±0.9 weeks). All survived PS cases demonstrated progressive pulmonary valve obstruction, not observed in fPA groups. AfNT-proBNP were significantly higher in fPA and PS than in normal RVOT group (p<0.05). AfTnT was significantly higher in group A with PS than fPA and normal RVOT groups (p<0.05).

CONCLUSION

Among RVOT abnormality types in group A, amniotic fluid cardiac biomarkers were differently expressed, and clinical features were also differentiated. These findings provide insight into the pathophysiological influence on RVOT in MC twins. This article is protected by copyright. All rights reserved.

NT-proBNP Concentrations in the Umbilical Cord and Serum of Term Neonates: A Systematic Review and Meta-Analysis

The detection of NT-proBNP levels both in umbilical cord blood (UCB) samples and in serum samples collected from healthy term neonates during the neonatal period. A systematic review of relevant literature in accordance with PRISMA guidelines was conducted. For quality appraisal, the potential risk of bias was assessed using the BIOCROSS evaluation tool. The random-effects and fixed-effects models were used to calculate weighted mean differences with a corresponding 95% confidence interval. A total of forty (40) studies met the inclusion criteria for the systematic review. After further examination, eighteen (18) studies (1738 participants) from the UCB sample group and fourteen (14) studies (393 participants) from the serum sample group were selected to perform a meta-analysis. Using the fixed-effects model, the mean intervals of NT-proBNP in UCB and serum samples were 492 pg/mL (95% CI: 480−503 pg/mL) and 1341 pg/mL (95% CI: 1286−1397 pg/mL), respectively. A higher concentration of ΝΤ-proBNP was observed in the serum sample group compared to the UCB samples (p < 0.001). We present the intervals of NT-proBNP in UCB and in the serum of healthy term neonates. The determination of the potential effect of perinatal factors on the biomarker’s reference range was also aimed.

Metabolic Pathway of Cardiospecific Troponins: From Fundamental Aspects to Diagnostic Role (Comprehensive Review)

Many molecules of the human body perform key regulatory functions and are widely used as targets for the development of therapeutic drugs or as specific diagnostic markers. These molecules undergo a significant metabolic pathway, during which they are influenced by a number of factors (biological characteristics, hormones, enzymes, etc.) that can affect molecular metabolism and, as a consequence, the serum concentration or activity of these molecules. Among the most important molecules in the field of cardiology are the molecules of cardiospecific troponins (Tns), which regulate the processes of myocardial contraction/relaxation and are used as markers for the early diagnosis of ischemic necrosis of cardiomyocytes (CMC) in myocardial infarction (MI). The diagnostic value and diagnostic capabilities of cardiospecific Tns have changed significantly after the advent of new (highly sensitive (HS)) detection methods. Thus, early diagnostic algorithms of MI were approved for clinical practice, thanks to which the possibility of rapid diagnosis and determination of optimal tactics for managing patients with MI was opened. Relatively recently, promising directions have also been opened for the use of cardiospecific Tns as prognostic markers both at the early stages of the development of cardiovascular diseases (CVD) (arterial hypertension (AH), heart failure (HF), coronary heart disease (CHD), etc.), and in non-ischemic extra-cardiac pathologies that can negatively affect CMC (for example, sepsis, chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), etc.). Recent studies have also shown that cardiospecific Tns are present not only in blood serum, but also in other biological fluids (urine, oral fluid, pericardial fluid, amniotic fluid). Thus, cardiospecific Tns have additional diagnostic capabilities. However, the fundamental aspects of the metabolic pathway of cardiospecific Tns are definitively unknown, in particular, specific mechanisms of release of Tns from CMC in non-ischemic extra-cardiac pathologies, mechanisms of circulation and elimination of Tns from the human body, mechanisms of transport of Tns to other biological fluids and factors that may affect these processes have not been established. In this comprehensive manuscript, all stages of the metabolic pathway are consistently and in detail considered, starting from release from CMC and ending with excretion (removal) from the human body. In addition, the possible diagnostic role of individual stages and mechanisms, influencing factors is analyzed and directions for further research in this area are noted.

The Importance of Cardiac Troponin Metabolism in the Laboratory Diagnosis of Myocardial Infarction (Comprehensive Review)

The study of the metabolism of endogenous molecules is not only of great fundamental significance but also of high practical importance, since many molecules serve as drug targets and/or biomarkers for laboratory diagnostics of diseases. Thus, cardiac troponin molecules have long been used as the main biomarkers for confirmation of diagnosis of myocardial infarction, and with the introduction of high-sensitivity test methods, many of our ideas about metabolism of these cardiac markers have changed significantly. In clinical practice, there are opening new promising diagnostic capabilities of cardiac troponins, the understanding and justification of which are closely connected with the fundamental principles of the metabolism of these molecules. Our current knowledge about the metabolism of cardiac troponins is insufficient and extremely disconnected from various literary sources. Thus, many researchers do not sufficiently understand the potential importance of cardiac troponin metabolism in the laboratory diagnosis of myocardial infarction. The purpose of this comprehensive review is to systematize information about the metabolism of cardiac troponins and during the discussion to focus on the potential impact of cTns metabolism on the laboratory diagnosis of myocardial infarction. The format of this comprehensive review includes a sequential consideration and analysis of the stages of the metabolic pathway, starting from possible release mechanisms and ending with elimination mechanisms. This will allow doctors and researchers to understand the significant importance of cTns metabolism and its impact on the laboratory diagnosis of myocardial infarction.

Copeptin Concentrations in Plasma of Healthy Neonates in Relation to Water–Electrolyte Homeostasis in the Early Adaptation Period

Copeptin (CTproAVP) is a stable by-product of arginine–vasopressin synthesis and reflects its secretion by the pituitary gland, considered as a potential new marker of dehydration. The objective of the study was to investigate CTproAVP measured after the first 48 h of postnatal life in relation to serum effective osmolality, urine osmolality, and vessels filling according to the following variables: delivery mode, postnatal weight loss, fluids administered intravenously to the mother, and fluids given orally to the neonate. A prospective observational study was conducted with 200 healthy term infants (53% male) enrolled. Serum CTproAVP concentrations were measured using the ELISA kit; haematocrit, urine osmolality, serum effective osmolality were assessed after 48 h of life. Sonographic measurements of inferior vena cava (IVC) and aorta (Ao) were performed and IVC/Ao ratios were calculated. No correlations were found between CTproAVP concentrations and both serum effective osmolality and urine osmolality. There was also no association between CTproAVP concentrations and vessel filling represented by IVC/Ao index at 48 h of life.

Biology of Cardiac Troponins: Emphasis on Metabolism

Understanding of the biology of endo- and exogenous molecules, in particular their metabolism, is not only of great theoretical importance, but also of high practical significance, since many molecules serve as drug targets or markers for the laboratory diagnostics of many human diseases. Thus, cardiac troponin (cTns) molecules have long been used as key markers for the confirmation of diagnosis of myocardial infarction (MI), and with the introduction of contemporary (high sensitivity) test methods, many of our concepts related to the biology of these cardiac markers have changed significantly. In current clinical practice, there are opening new promising diagnostic capabilities of cTns, the understanding and justification of which is closely connected with the theoretical principles of the metabolism of these molecules. However, today, the biology and metabolism of cTns have not been properly investigated; in particular, we do not know the precise mechanisms of release of these molecules from the myocardial cells (MCs) of healthy people and the mechanisms of circulation, and the elimination of cTns from the bloodstream. The main purpose of this manuscript is to systematize information about the biology of cTns, with an emphasis on the metabolism of cTns. The format of this paper, starting with the release of cTns in the blood and concluding with the metabolism/filtration of troponins, provides a comprehensive yet logically easy way for the readers to approach our current knowledge in the framework of understanding the basic mechanisms by which cTns are produced and processed. Conclusions. Based on the analysis of the current literature, the important role of biology and all stages of metabolism (release, circulation, removal) of cTns in laboratory diagnostics should be noted. It is necessary to continue studying the biology and metabolism of cTns, because this will improve the differential diagnosis of MI and i a new application of cTns immunoassays in current clinical practice.

Application of B-Type Natriuretic Peptide in Neonatal Diseases

Numerous congenital or secondary diseases, including, heart disease, respiratory disease, sepsis and many others, can lead to neonatal death. B-type natriuretic peptide (BNP) is a peptide hormone secreted by ventricular cells following an increase in ventricular wall tension. BNP functions to promote vasodilation, diuresis, and sodium release to regulate blood pressure. BNP is a sensitive index reflecting ventricular function, which may aid the diagnosis and monitoring of various neonatal diseases. In neonates, there is currently no consensus on a reference BNP level, as the plasma BNP concentration of healthy newborns varies with age, peaks in the first week after birth, and then gradually decreased to a stable level. In disease states, the correlation between the plasma BNP concentration and the results of echocardiography is good, which is of great significance in the screening, monitoring, and prognosis evaluation of neonatal cardiovascular diseases, including congenital heart disease, patent ductus arteriosus, etcetera. It also facilitates the judgment of the efficacy of treatment and perioperative management. Moreover, the monitoring of plasma BNP concentration provides guidance for the diagnosis, evaluation, and treatment selection of certain neonatal respiratory diseases and neonatal sepsis. This review summarizes the normal BNP values and discusses the application value of BNP in relation to physiological and pathological aspects in neonates.

Copeptin and Stress

Vasopressin (AVP) and copeptin are released in equimolar amounts from the same precursor. Due to its molecular stability and countless advantages as compared with AVP, copeptin perfectly mirrors AVP presence and has progressively emerged as a reliable marker of vasopressinergic activation in response to osmotic and hemodynamic stimuli in clinical practice. Moreover, evidence highlighting the prognostic potential of copeptin in several acute diseases, where the activation of the AVP system is primarily linked to stress, as well as in psychologically stressful conditions, has progressively emerged. Furthermore, organic stressors induce a rise in copeptin levels which, although non-specific, is unrelated to plasma osmolality but proportional to their magnitude: suggesting disease severity, copeptin proved to be a reliable prognostic biomarker in acute conditions, such as sepsis, early post-surgical period, cardiovascular, cerebrovascular or pulmonary diseases, and even in critical settings. Evidence on this topic will be briefly discussed in this article.

Pregnancy-specific Reference Intervals for BNP and NT-pro BNP-Changes in Natriuretic Peptides Related to Pregnancy

Context

Cardiac disease is the leading cause of maternal mortality in the UK, so accurate cardiovascular diagnoses in pregnancy are essential. BNP (B-type natriuretic peptide) and NT-pro BNP (N-terminal-pro BNP) are useful clinical tools for investigating suspected peripartum cardiomyopathy but, as the pregnancy-specific reference intervals are undefined, it is uncertain how they should be interpreted in pregnant women.

Objectives

To define trimester-specific 95% reference intervals for BNP and NT-pro BNP in pregnancy.

Methods

Longitudinal study of 260 healthy pregnant women, with sampling in each trimester.

Results

The upper reference limit for NT-pro BNP was 200 pg/mL in the first and second trimesters, and 150 pg/mL in the third. Levels were significantly reduced in overweight women in the third trimester (P = .0001), which supports the partitioning of reference intervals by body mass index (BMI). The upper limit for BNP was 50 pg/mL, with no detectable trimester-related differences. Although other biomarkers (hemoglobin and platelets) fell throughout pregnancy, both natriuretic peptides were initially elevated before falling by the third trimester, suggesting that the observed changes in natriuretic peptides are driven by dynamic interplay between cardiac strain and progressive hemodilution. NT-pro BNP in the first trimester was inversely associated with neonatal birthweight at term (P = .011).

Conclusion

Cardiac biomarkers have an important role for investigating suspected disease in high-risk pregnant women, but a robust assessment of the levels expected in healthy pregnant women is an essential prerequisite to their application in clinical practice. This study has defined trimester- and BMI-specific reference intervals for NT-pro BNP and BNP, which may improve how women with suspected cardiovascular disease are investigated in pregnancy.