Cardiovascular biomarkers pro-atrial natriuretic peptide and pro-endothelin-1 to monitor ductus arteriosus evolution in very preterm infants

Vasoactive peptides as biomarkers for the prediction of retinopathy of prematurity

BACKGROUND

Retinopathy of prematurity (ROP) is a major complication in preterm infants. We assessed if plasma levels of midregional pro-atrial natriuretic peptide (MR-proANP) and C-terminal pro-endothelin-1 (CT-proET1) serve as early markers for subsequent ROP development in preterm infants <32 weeks gestation.

METHODS

Prospective, two-centre, observational cohort study. MR-proANP and CT-proET1 were measured on day seven of life. Associations with ROP ≥ stage II were investigated by univariable and multivariable logistic regression models.

RESULTS

We included 224 infants born at median (IQR) 29.6 (27.1-30.8) weeks gestation and birth weight of 1160 (860-1435) g. Nineteen patients developed ROP ≥ stage II. MR-proANP and CT-proET1 levels were higher in these infants (median (IQR) 864 (659-1564) pmol/L and 348 (300-382) pmol/L, respectively) compared to infants without ROP (median (IQR) 299 (210-502) pmol/L and 196 (156-268) pmol/L, respectively; both P < 0.001). MR-proANP and CT-proET1 levels were significantly associated with ROP ≥ stage II in univariable logistic regression models and after adjusting for co-factors, including gestational age and birth weight z-score.

CONCLUSIONS

MR-proANP and CT-proET1 measured on day seven of life are strongly associated with ROP ≥ stage II in very preterm infants and might improve early prediction of ROP in the future.

IMPACT

Plasma levels of midregional pro-atrial natriuretic peptide and C-terminal pro-endothelin-1 measured on day seven of life in very preterm infants show a strong association with development of retinopathy of prematurity ≥ stage II. Both biomarkers have the potential to improve early prediction of retinopathy of prematurity. Vasoactive peptides might allow to reduce the proportion of screened infants substantially.

N-terminal pro-brain natriuretic peptide used for screening hemodynamically significant patent ductus arteriosus in very low birth weight infants: How and when?

BACKGROUND

N-terminal pro-B-type natriuretic peptide (NTproBNP) appears to be a useful tool for diagnosing hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. However, a consensus for its application has not been reached.

OBJECTIVE

The present study aims to evaluate the role of NTproBNP in predicting hsPDA in preterm infants, and explore the optimal cutoff value and testing-time.

METHODS

A prospective blind study of 120 preterm infants with birth weights of < 1,500 g was conducted at the NICU of Peking University Shenzhen Hospital. Blood samples were successively collected on the first three days after birth for NTproBNP analysis. Echocardiographies were performed on day three of life to confirm the status of the ductus arteriosus. A receiver operating characteristic curve (ROC) analysis was performed to determine the ability of NTproBNP to recognize hsPDA.

RESULTS

NTproBNP was significantly higher in infants with hsPDA, than in infants in the control group, on both day two (P < 0.001) and day three (P < 0.001). On day two, a NTproBNP cutoff value of 3,689.0 pmol/L offered an optimal predictive value for hsPDA, while on day three, the optimal cut-off value for hsPDA was 2,331.5 pmol/L. The investigators proposes day three of life (48-72 hours) as the optimal testing time.

CONCLUSION

The NTproBNP biomarker during the early neonatal period can be a useful tool for screening and assessing hsPDA in premature infants, especially on day three of life.

Cardiovascular biomarkers in the evaluation of patent ductus arteriosus in very preterm neonates: A cohort study

BACKGROUND

The evaluation of the patent ductus arteriosus (PDA) in the very premature neonate is a challenge. Echocardiography provides an interpretation of the hemodynamic condition. It is however, only a snapshot. Biomarkers may represent a physiological response to the hemodynamic alterations brought on by the PDA and may add to the identification of the clinical significant PDA.

AIM

To investigate the association between mid regional proadrenomodulin (MR-proADM), N-terminal pro b-type natriuretic peptide (NT-proBNP), mid regional pro-atrial natriuretic peptide (MR-proANP), C-terminal pro endothelin-1 (CT-proET1) and copeptin and echocardiographic measures of PDA.

STUDY DESIGN

Cohort study with echocardiography performed on day 3 and 6. Blood samples from day 3.

SUBJECT

139 consecutive neonates born at a gestational age <32 weeks.

OUTCOME MEASURES

The main outcomes were presence of a PDA day 3 and 6, PDA diameter, left atrium to aorta ratio (LA:Ao-ratio), and descending aorta diastolic flow (DADF).

RESULTS

Adjusted plasma levels of all investigated biomarkers, except CT-proET1, were found to be associated with both PDA diameter and LA:Ao-ratio, and also the presence of a large PDA. CT-proET1 and copeptin was found to be associated with abnormal DADF. Using pre-specified cut-off values NT-proBNP and MR-proANP day 3 seemed to be of value in identifying a large PDA day 3 and 6 in very preterm neonates.

CONCLUSION

Among the investigated biomarkers NT-proBNP and MR-proANP performed best in relation to echocardiographic markers of PDA severity in very preterm neonates.

Spontaneous Closure of the Ductus Arteriosus in Preterm Infants: A Systematic Review

The optimal management strategy for patent ductus arteriosus in preterm infants remains a topic of debate. Available evidence for a treatment strategy might be biased by the delayed spontaneous closure of the ductus arteriosus in preterm infants, which appears to depend on patient characteristics. We performed a systematic review of all literature on PDA studies to collect patient characteristics and reported numbers of patients with a ductus arteriosus and spontaneous closure. Spontaneous closure rates showed a high variability but were lowest in studies that only included preterm infants with gestational ages below 28 weeks or birth weights below 1,000 g (34% on day 4; 41% on day 7) compared to studies that also included infants with higher gestational ages or higher birth weights (up to 55% on day 3 and 78% on day 7). The probability of spontaneous closure of the ductus arteriosus keeps increasing until at least 1 week after birth which favors delayed treatment of only those infants that do not show spontaneous closure. Better prediction of the spontaneous closure of the ductus arteriosus in the individual newborn is a key factor to find the optimal management strategy for PDA in preterm infants.

Pro-atrial natriuretic peptide and pro-adrenomedullin before cardiac surgery in children. Can we predict the future?

INTRODUCTION AND OBJECTIVE

Pro-atrial natriuretic peptide (proANP) and pro-adrenomedullin (proADM) levels increase in acute heart failure and sepsis. After cardiac surgery, children may require increased support in the intensive care unit and may develop complications. The aim of this study was to evaluate the utility of proANP and proADM values, determined prior to cardiac surgery, for predicting the need for increased respiratory or inotropic support during the post-operative period.

METHODS

This was a prospective study in children. Biomarkers were analyzed before surgery using a single blood test. The primary endpoints were the need for greater respiratory and/or inotropic support during the post-operative period. Secondary endpoints were the relationship between these biomarkers and complications after surgery.

RESULTS

One hundred thirteen patients were included. ProANP and proADM were higher in children who required greater respiratory and inotropic support, especially proANP; for increased respiratory support, 578.9 vs. 106.6 pmol/L (p = 0.004), and for increased inotropic support, 1938 vs. 110.4 pmol/L (p = 0.002). ProANP had a greater AUC than proADM for predicting increased respiratory support after surgery: 0.791 vs. 0.724. A possible cut-off point for proANP could be ≥ 325 pmol/L (sensitivity = 66.7% and specificity = 88.8%). In the multivariate analysis, the logarithmic transformation of proANP was independently associated with the need for increased respiratory support (OR = 3.575). Patients who presented a poor outcome after cardiac surgery also had higher biomarker values (proADM, p = 0.013; proANP, p = 0.001).

CONCLUSIONS

Elevated proANP before cardiac surgery may identify which children will need more respiratory and inotropic support during the post-operative period.

Exploration of potential biochemical markers for persistence of patent ductus arteriosus in preterm infants at 22-27 weeks' gestation

BACKGROUND

Early identification of infants at risk for complications from patent ductus arteriosus (PDA) may improve treatment outcomes. The aim of this study was to identify biochemical markers associated with persistence of PDA, and with failure of pharmacological treatment for PDA, in extremely preterm infants.

METHODS

Infants born at 22-27 weeks' gestation were included in this prospective study. Blood samples were collected on the second day of life. Fourteen biochemical markers associated with factors that may affect PDA closure were analyzed and related to persistent PDA and to the response of pharmacological treatment with ibuprofen.

RESULTS

High levels of B-type natriuretic peptide, interleukin-6, -8, -10, and -12, growth differentiation factor 15 and monocyte chemotactic protein 1 were associated with persistent PDA, as were low levels of platelet-derived growth factor. High levels of erythropoietin were associated with both persistent PDA and failure to close PDA within 24 h of the last dose of ibuprofen.

CONCLUSIONS

High levels of inflammatory markers were associated with the persistence of PDA. High levels of erythropoietin were associated with both the persistence of PDA and failure to respond to pharmacological treatment.

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

Background: Several cardiovascular biomarkers have regulatory functions in perinatal physiology. Aim: This study aimed to analyze the feto-maternal distribution pattern of biomarkers in samples of amniotic fluid, umbilical arterial blood, umbilical venous blood, and maternal blood samples, and to establish reference values. Each linked sample set consisted of the combined samples obtained in an individual pregnancy. Study design: We performed a prospective, observational, cross-sectional, single-center study. Subjects: The sample cohort included 189 neonates who were born to 170 mothers. A total of 162/189 neonates were full term and 129/189 were delivered by elective cesarean section. Outcome measures: Midregional pro-adrenomedullin (MRproADM [nmol/L]), midregional pro-atrial natriuretic peptide (MRproANP [pmol/L]), brain natriuretic peptide (BNP [pg/mL]), N-terminal pro-brain natriuretic peptide (NTproBNP [pg/mL]), copeptin [pmol/L], and high-sensitive troponin I (hsTnI [pg/mL]) levels were measured. Results: In singleton, full-term, primary cesarean deliveries (n = 91), biomarker levels (median, [IQR]) at delivery were as follows. MRproADM levels in umbilical arterial blood/umbilical venous blood/amniotic fluid/maternal blood were 0.88 (0.20)/0.95 (0.18)/2.80 (1.18)/1.10 (0.54), respectively. MRproANP levels were 214.23 (91.38)/216.03 (86.15)/0.00 (3.82)/50.67 (26.81), respectively. BNP levels were 14.60 (25.18)/22.08 (18.91)/7.15 (6.01)/6.20 (18.23), respectively. NTproBNP levels were 765.48 (555.24)/816.45 (675.71)/72.03 (55.58)/44.40 (43.94), respectively. Copeptin levels were 46.17 (290.42)/5.54 (9.08)/9.97 (7.44)/4.61 (4.59), respectively. Levels of hsTnI were 6.20 (4.25)/5.60 (5.01)/0.45 (1.73)/2.50 (2.40), respectively. Conclusion: We determined reference values for biomarkers in term neonates delivered by primary cesarean section in amniotic fluid, umbilical arterial and venous blood, and maternal blood. Biomarkers in the fetal circulation appear to be of primary fetal origin, except for MRproADM.

Cardiac biomarkers and haemodynamically significant patent ductus arteriosus in preterm infants

Accurately defining haemodynamically significant patent ductus arteriosus (PDA) in preterm infants who are at risk of PDA related morbidities are active areas of neonatal research. Natriuretic peptides are cardiac hormones that respond to volume and pressure loading, with elevated plasma levels found in infants with PDA. In the preterm neonatal setting, studies to date have predominantly investigated the ability of these biomarkers to discriminate between infants with and without a PDA at various postnatal ages. Their clinical utility has therefore been exclusively evaluated as a method of triaging cases of suspected hsPDA to decrease the need for echocardiograms, and to monitor treatment response. Biomarkers are yet to be robustly investigated for their ability to predict important PDA associated morbidities. In this review, we examine the most recent literature to date on the use of biomarkers in the management of PDA.

Plasma Levels of Macrophage Migration Inhibitory Factor and d-Dopachrome Tautomerase Show a Highly Specific Profile in Early Life

Macrophage migration inhibitory factor (MIF) is a pleiotropic, constitutively expressed, pro-inflammatory cytokine and an important regulator of immune responses. d-dopachrome tautomerase (DDT), a newly described member of the MIF protein superfamily, shares sequence homology and biological activities with MIF. We recently reported that high expression levels of MIF sustain innate immune responses in newborns. Here, we elected to further characterize age-dependent MIF expression and to define whether DDT shares a similar expression profile with MIF. Therefore, we delineated the circulating concentrations of MIF and DDT throughout life using a large cohort of 307 subjects including fetuses, newborns, infants, children, and adults. Compared to levels measured in healthy adults (median: 5.7 ng/ml for MIF and 16.8 ng/ml for DDT), MIF and DDT plasma concentrations were higher in fetuses (median: 48.9 and 29.6 ng/ml), increased further at birth (median: 82.6 and 52.0 ng/ml), reached strikingly elevated levels on postnatal day 4 (median: 109.5 and 121.6 ng/ml), and decreased to adult levels during the first months of life. A strong correlation was observed between MIF and DDT concentrations in all age groups (R = 0.91, P < 0.0001). MIF and DDT levels correlated with concentrations of vascular endothelial growth factor, a protein upregulated under low oxygen tension and implicated in vascular and lung development (R = 0.70, P < 0.0001 for MIF and R = 0.65, P < 0.0001 for DDT). In very preterm infants, lower levels of MIF and DDT on postnatal day 6 were associated with an increased risk of developing bronchopulmonary dysplasia and late-onset neonatal sepsis. Thus, MIF and DDT plasma levels show a highly specific developmental profile in early life, supporting an important role for these cytokines during the neonatal period.

Diagnostic performance and reference values of novel biomarkers of paediatric heart failure

OBJECTIVE

Biomarkers play a pivotal role in heart failure (HF) management. Reference values and insights from studies in adults cannot be extrapolated to the paediatric population due to important differences in pathophysiology and compensatory reserve. We assessed the diagnostic utility of four novel biomarkers in paediatric HF.

METHODS

Midregional (MR) pro-atrial natriuretic peptide (proANP), soluble ST2 (sST2), growth differentiation factor-15 (GDF-15), MR-pro-adrenomedullin (proADM) and N-terminal pro-B natriuretic peptide (NT-proBNP) were measured in 114 patients and 89 controls. HF was defined as the presence of HF symptoms and/or abnormal systolic ventricular function. Receiver-operating characteristics were plotted, and the area under the curve (AUC) was measured. This was repeated for subgroups with cardiomyopathy and congenital heart disease (CHD). Ventricular systolic function was measured by magnetic resonance or echocardiography. Reference values were calculated according to the current guidelines.

RESULTS

The AUC for diagnosing HF was 0.76 for MR-proANP (CI 0.70 to 0.84) and 0.82 for NT-proBNP (CI 0.75 to 0.88). These parameters performed similarly in the subgroups with CHD and cardiomyopathy. By contrast, MR-proADM, GDF-15 and sST2 performed poorly. When used in conjunction with NT-proBNP, no parameter added significantly to its diagnostic accuracy. NT-proBNP, MR-proANP, GDF-15 and sST2 could accurately discriminate between patients with preserved and patients with poor functional status. In a subset of patients with dilated cardiomyopathy, NT-proBNP, MR-proANP, MR-proADM and GDF-15 were associated with poor LV function.

CONCLUSIONS

MR-proANP could accurately detect HF in children and adolescents. Its diagnostic performance was comparable with that of NT-proBNP, regardless of the underlying condition. Reference values are presented.

Cardiovascular biomarkers in paired maternal and umbilical cord blood samples at term and near term delivery

BACKGROUND

Cardiovascular biomarkers might help to identify fetuses or pregnancies at risk.

AIM

To examine the umbilical cord neonatal and maternal levels of cardiovascular biomarkers at the time of delivery, and to correlate maternal and fetal biomarker levels to each other, to gestational age and to delivery mode.

STUDY DESIGN

In a prospective, observational, cross-sectional, single-center study biomarkers were measured in paired maternal and umbilical venous cord blood samples.

SUBJECTS

The sample cohort included 66 sets of fetal and maternal blood samples (11 after multiple gestation, 53 after cesarean section, 17 after exposure to labor).

OUTCOME MEASURES

Midregional pro-adrenomedullin (MRproADM), midregional-pro atrial natriuretic peptide (MRproANP), brain natriuretic peptide (BNP), n-terminal-pro brain natriuretic peptide (NTproBNP), copeptin, and high sensitive troponin I (hsTnI) levels were measured.

RESULTS

Mean ± SEM for biomarker levels in umbilical venous/maternal blood were: MRproADM [nmol/L] 1.02 ± 0.04/1.24 ± 0.08, MRproANP [pmol/L] 215.53 ± 12.96/54.65 ± 3.41, BNP [pg/mL] 32.02 ± 3.37/19.76 ± 3.29, NTproBNP [pg/mL] 1228.94 ± 91.73/71.48 ± 8.65, copeptin [pmol/L] 103.42 ± 22.89/10.41 ± 1.71, and hsTnI [pg/mL] 13.54 ± 5.17/4.91 ± 2.37. Fetal MRproANP, NTproBNP, and BNP were inversely correlated with gestational age. Maternal and fetal MRproANP (r=0.472, p=0.002) and copeptin (r=0.572, p<0.001) levels were correlated, whereas there was no feto-maternal correlation for the other biomarkers. Fetal copeptin was elevated after exposure to labor.

CONCLUSIONS

Biomarker levels appear to be regulated independently in mother and fetus. Fetal biomarkers are influenced by gestational age and delivery mode. In this study on term and near term pregnancies without specific fetal pathology, correlation between paired maternal and fetal biomarker levels was weak or not demonstrable.

What is new for patent ductus arteriosus management in premature infants in 2015?

PURPOSE OF REVIEW

A patent ductus arteriosus (PDA) in premature infants is common and is associated with a number of adverse outcomes. The purpose of this review is to discuss recent literature in PDA diagnosis and management.

RECENT FINDINGS

The diagnosis of a 'hemodynamically significant' PDA is challenging and a robust definition is lacking. The risks and benefits of therapies, either medical or surgical, designed to close the PDA, are controversial. Oral acetaminophen has gained increasing attention as an alternative pharmaceutical agent for PDA closure in premature infants, although safety concerns remain. Compared to surgical ligation, transcatheter PDA closure may be associated with less risk and fewer adverse events. Both aggressive and conservative management of PDA has similar clinically important outcomes, although the strength of evidence is derived mostly from cohort studies.

SUMMARY

Clinicians should weigh the potential adverse effects of pharmaceutical or surgical PDA closure against the likelihood of spontaneous closure. The infant population most likely to benefit from PDA closure remains ill-defined and clinical context is recommended.

Plasma Proendothelin-1 as an Early Marker of Bronchopulmonary Dysplasia

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a common complication in preterm infants. Clinical prediction of BPD at an early stage in life is difficult. Plasma proendothelin-1 (CT-proET-1) is a lung injury biomarker in pulmonary hypertension and respiratory distress.

OBJECTIVE

To assess the prognostic ability of CT-proET-1 in BPD.

METHODS

In 227 prospectively enrolled preterm infants born at <32 weeks gestational age (GA), plasma CT-proET-1 was measured at birth, day of life (DOL) 2, 3, 6 and 28, and at 36 weeks postmenstrual age (PMA). BPD was defined as mild in infants requiring supplemental oxygen at DOL 28 and moderate/severe in those requiring it at 36 weeks PMA.

RESULTS

The predictive ability of CT-proET-1 for any BPD was poor at birth [area under the ROC curve (AUC) 0.654, 95% CI 0.494-0.814], moderate at DOL 2 and 3 (AUC 0.769, 95% CI 0.666-0.872) and excellent at DOL 6 (AUC 0.918, 95% CI 0.840-0.995). Multivariable regression analysis revealed that CT-proET-1 levels at DOL 2, 3, 6 and 28 were strongly related to the duration of oxygen supplementation, independently of GA and the duration of respiratory support.

CONCLUSIONS

CT-proET-1 is a novel promising biomarker for predicting the development of BPD in preterm infants when measured at the end of the first week of life.