Diagnosing significant PDA using natriuretic peptides in preterm neonates: a systematic review

Newborn Screening for High-Risk Congenital Heart Disease by Dried Blood Spot Biomarker Analysis

Importance

Congenital heart disease (CHD) is the most common human organ malformation, affecting approximately 1 of 125 newborns globally.

Objectives

Assessing the performance of 2 diagnostic tests using minimal amounts of dried blood spots (DBS) to identify high-risk CHD compared with controls in a Swedish cohort of neonates.

Design, Setting, and Participants

This diagnostic study took place in Sweden between 2019 and 2023 and enrolled full-term babies born between 2005 and 2023. All cases were identified through centralized pediatric cardiothoracic surgical services in Lund and Gothenburg, Sweden. Controls were followed up for 1 year to ensure no late presentations of high-risk CHD occurred. Cases were verified through surgical records and echocardiography.

Exposure

High-risk CHD, defined as cases requiring cardiac surgical management during infancy due to evolving signs of heart failure or types in which the postnatal circulation depends on patency of the arterial duct. Using 3-μL DBS samples, automated quantitative tests for NT-proBNP and interleukin 1 receptor-like 1 (IL-1 RL1; formerly known as soluble ST2) were compared against established CHD screening methods.

Main Outcomes and Measures

Performance of DBS tests to detect high-risk CHD using receiver operating characteristic curves; Bland-Altman and Pearson correlation analyses to compare IL-1 RL1 DBS with plasma blood levels.

Results

A total of 313 newborns were included (mean [SD] gestational age, 39.4 [1.3] weeks; 181 [57.8%] male). Mean (SD) birthweight was 3495 (483) grams. Analyzed DBS samples included 217 CHD cases and 96 controls. Among the CHD cases, 188 participants (89.3%) were high-risk types, of which 73 (38.8%) were suspected prenatally. Of the 188 high-risk cases, 94 (50.0%) passed pulse oximetry screening and 36 (19.1%) were initially discharged after birth without diagnoses. Combining NT-proBNP and IL-1 RL1 tests performed well in comparison with existing screening methods and enabled additional identification of asymptomatic babies with receiver operating characteristic area under the curve 0.95 (95% CI, 0.93-0.98).

Conclusions and relevance

In this diagnostic study, NT-proBNP and IL-1 RL1 DBS assays identified high-risk CHD in a timely manner, including in asymptomatic newborns, and improved overall screening performance in this cohort from Sweden. Prospective evaluation of this novel approach is warranted.

NT-PROBNP as a screening tool for low-risk patent ductus arteriousus: a follow-up validation study

The purpose of the study is to test whether NT-proBNP serves as a screening tool for low-risk patent ductus arteriosus and safely avoids routine early echocardiography. This is a prospective observational study in preterm infants ≤32 weeks of gestational age. Infants with ≥5100 pg/ml (positive screening) at 48-72 hours of life received comprehensive echocardiography and were treated according to shunt severity. Infants with NT-proBNP below 5100 pg/ml (negative screening) were managed expectantly. The main outcome was need for ductus treatment within the first 7 days of life. One hundred twenty-five infants were included; 82 had a negative NT-proBNP screening and 43 had a positive NT-proBNP screening. No infant (0%) with a negative screening was treated for ductus while 26 (60.4%) with a positive screening were treated (p < 0.001). NT-proBNP avoided a 65.6% of routine echocardiograms. NT-proBNP had an excellent performance to predict PDA treatment (AUC = 0.967).Conclusion: NT-proBNP at 48-72 hours of life has an excellent performance to detect low risk and avoids unnecessary echocardiograms. This may contribute to optimize PDA management in terms of resource utilization.

Diagnostic Accuracy of Urinary N Terminal pro-B Type Natriuretic Peptides for Hemodynamically Significant-Patent Ductus Arteriosus in Preterm Infants

BACKGROUND

Echocardiography is the gold standard for the diagnosis hemodynamically significant-patent ductus arteriosus (hs-PDA). It requires trained personnel and is not readily available. Urinary biomarkers can be used as an adjunct.

OBJECTIVE

The objective of this study was to systematically review the diagnostic accuracy of urinary N terminal pro-B type natriuretic peptides (NT-proBNP) for hs-PDA in preterm neonates.

METHODS

We included studies that evaluated urinary NT-proBNP and urinary NT-proBNP/creatinine ratio (index tests) in preterm neonates with hs-PDA (participants) in comparison with echocardiogram (reference standard). Methodological quality and certainty of evidence were assessed using Quality Assessment of Diagnostic-Accuracy Studies (QUADAS-2) and Grading of Recommendations Assessment, Development and Evaluation (GRADE), respectively.

RESULTS

Low quality of evidence suggests that urinary NT-proBNP has modest sensitivity and specificity for the diagnosis of a hs-PDA, with variation in accuracy based on assay and patient characteristics.

CONCLUSION

Urinary NT-proBNP assays must be locally validated for specific patient populations and further studies to support its use must be performed.

Multisystem inflammatory disease in neonates (MIS-N) due to maternal COVID-19

Multisystem inflammatory disease in neonates (MIS-N) is a disease of immune dysregulation presenting in the newborn period. Thouvgh its etiopathogenesis is proposed to be similar to multisystem inflammatory disease in Children (MIS-C), the exact pathophysiology is largely unknown as of present. The definition of MIS-N is contentious. The evidence for its incidence, the clinical features, profile of raised inflammatory markers, treatment strategies and outcomes stem from case reports, case series and cohort studies with small sample sizes. Though the incidence of MIS-N in severe acute respiratory syndrome caused by the coronavirus CoVID-2 (SARS-CoV-2) infected asymptomatic neonates is low, its incidence in symptomatic neonates is relatively higher. Further, amongst the neonates who are treated as MIS-N, the mortality rate is high. The review also evaluates the various other unresolved aspects of MIS-N from limited published literature and identifies knowledge gaps which could be areas of future research.

Brain natriuretic peptide and N-terminal brain natriuretic peptide for the diagnosis of haemodynamically significant patent ductus arteriosus in preterm neonates

BACKGROUND

Echocardiogram is the reference standard for the diagnosis of haemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. A simple blood assay for brain natriuretic peptide (BNP) or amino-terminal pro-B-type natriuretic peptide (NT-proBNP) may be useful in the diagnosis and management of hsPDA, but a summary of the diagnostic accuracy has not been reviewed recently.

OBJECTIVES

Primary objective: To determine the diagnostic accuracy of the cardiac biomarkers BNP and NT-proBNP for diagnosis of haemodynamically significant patent ductus arteriosus (hsPDA) in preterm neonates. Our secondary objectives were: to compare the accuracy of BNP and NT-proBNP; and to explore possible sources of heterogeneity among studies evaluating BNP and NT-proBNP, including type of commercial assay, chronological age of the infant at testing, gestational age at birth, whether used to initiate medical or surgical treatment, test threshold, and criteria of the reference standard (type of echocardiographic parameter used for diagnosis, clinical symptoms or physical signs if data were available).

SEARCH METHODS

We searched the following databases in September 2021: MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Web of Science. We also searched clinical trial registries and conference abstracts. We checked references of included studies and conducted cited reference searches of included studies. We did not apply any language or date restrictions to the electronic searches or use methodological filters, so as to maximise sensitivity.

SELECTION CRITERIA

We included prospective or retrospective, cohort or cross-sectional studies, which evaluated BNP or NT-proBNP (index tests) in preterm infants (participants) with suspected hsPDA (target condition) in comparison with echocardiogram (reference standard).

DATA COLLECTION AND ANALYSIS

Two authors independently screened title/abstracts and full-texts, resolving any inclusion disagreements through discussion or with a third reviewer. We extracted data from included studies to create 2 × 2 tables. Two independent assessors performed quality assessment using the Quality Assessment of Diagnostic-Accuracy Studies-2 (QUADAS 2) tool. We excluded studies that did not report data in sufficient detail to construct 2 × 2 tables, and where this information was not available from the primary investigators. We used bivariate and hierarchical summary receiver operating characteristic (HSROC) random-effects models for meta-analysis and generated summary receiver operating characteristic space (ROC) curves. Since both BNP and NTproBNP are continuous variables, sensitivity and specificity were reported at multiple thresholds. We dealt with the threshold effect by reporting summary ROC curves without summary points.

MAIN RESULTS

We included 34 studies: 13 evaluated BNP and 21 evaluated NT-proBNP in the diagnosis of hsPDA. Studies varied by methodological quality, type of commercial assay, thresholds, age at testing, gestational age and whether the assay was used to initiate medical or surgical therapy. We noted some variability in the definition of hsPDA among the included studies. For BNP, the summary curve is reported in the ROC space (13 studies, 768 infants, low-certainty evidence). The estimated specificities from the ROC curve at fixed values of sensitivities at median (83%), lower and upper quartiles (79% and 92%) were 93.6% (95% confidence interval (CI) 77.8 to 98.4), 95.5% (95% CI 83.6 to 98.9) and 81.1% (95% CI 50.6 to 94.7), respectively. Subgroup comparisons revealed differences by type of assay and better diagnostic accuracy at lower threshold cut-offs (< 250 pg/ml compared to ≥ 250 pg/ml), testing at gestational age < 30 weeks and chronological age at testing at one to three days. Data were insufficient for subgroup analysis of whether the BNP testing was indicated for medical or surgical management of PDA. For NT-proBNP, the summary ROC curve is reported in the ROC space (21 studies, 1459 infants, low-certainty evidence). The estimated specificities from the ROC curve at fixed values of sensitivities at median (92%), lower and upper quartiles (85% and 94%) were 83.6% (95% CI 73.3 to 90.5), 90.6% (95% CI 83.8 to 94.7) and 79.4% (95% CI 67.5 to 87.8), respectively. Subgroup analyses by threshold (< 6000 pg/ml and ≥ 6000 pg/ml) did not reveal any differences. Subgroup analysis by mean gestational age (< 30 weeks vs 30 weeks and above) showed better accuracy with < 30 weeks, and chronological age at testing (days one to three vs over three) showed testing at days one to three had better diagnostic accuracy. Data were insufficient for subgroup analysis of whether the NTproBNP testing was indicated for medical or surgical management of PDA. We performed meta-regression for BNP and NT-proBNP using the covariates: assay type, threshold, mean gestational age and chronological age; none of the covariates significantly affected summary sensitivity and specificity.

AUTHORS' CONCLUSIONS

Low-certainty evidence suggests that BNP and NT-proBNP have moderate accuracy in diagnosing hsPDA and may work best as a triage test to select infants for echocardiography. The studies evaluating the diagnostic accuracy of BNP and NT-proBNP for hsPDA varied considerably by assay characteristics (assay kit and threshold) and infant characteristics (gestational and chronological age); hence, generalisability between centres is not possible. We recommend that BNP or NT-proBNP assays be locally validated for specific populations and outcomes, to initiate therapy or follow response to therapy.

Can NT-proBNP Levels Be an Early Biomarker of Reduced Left Ventricular Ejection Fraction in Preterm Infants?

Background/Objective: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a cardiac natriuretic hormone that cardiomyocytes release in response to ventricular stretch. It helps with the diagnosis of heart failure in adults, but this application in preterm infants has rarely been reported. This study aimed to evaluate whether NT-proBNP could be used for the early detection of reduced cardiac ejection fraction in preterm infants and the optimal timing for NT-proBNP assessment. Design/Methods: This prospective, single-center, observational study enrolled all preterm infants with NT-proBNP measurements from October 2014 to February 2022. They underwent echocardiographic examinations within 48 h of the NT-proBNP measurements. Reduced left ventricular ejection fraction was defined as below 60%. Receiver operator characteristic (ROC) curves were generated to assess the optimal NT-proBNP cutoff point for the early prediction of reduced cardiac ejection fraction. Results: A total of 68 preterm infants were enrolled, with a total of 134 NT-proBNP measurements being available for analysis. Reduced left ventricular ejection fraction was present in seven infants (10.3%) due to various underlying diseases. The NT-proBNP cutoff level for detecting reduced left ventricular ejection fraction was 9248 pg/mL, with 71.4% sensitivity and 60.8% specificity; the area under the curve was 0.623 (95% CI: 0.487~0.760). The threshold for the optimal postnatal age for applying NT-proBNP to detect reduced left ventricular ejection fraction was >2 days of life (AUC: 0.682; 95% CI: 0.518~0.845), with 70% sensitivity and 67.1% specificity. Conclusions: Although the NT-proBNP levels declined dramatically after birth, a NT-proBNP serum level of 9248 pg/mL might be helpful for the early detection of reduced ejection fraction in preterm infants, and the optimal age for detection was after 2 days of life.

B-type Natriuretic Peptide: A Diagnostic Biomarker for a Hemodynamically Significant PDA

Background: B-type natriuretic peptide (BNP) it has been reported to be a useful biomarker for the severity of hemodynamically significant patent ductus arteriosus (HsPDA) in premature infants. Objective: To assess serum levels of BNP in premature neonates with echocardiographically-confirmed hemodynamically significant and non-significant PDA (HnsPDA) and to explore the effect of PDA on left ventricular function. We also aimed to detect the level of BNP that differentiates between HsPDA and HnsPDA. Patients and methods: This was a cross-sectional observational study conducted on 73 randomly selected preterm neonates with HsPDA or hemodynamically nonsignificant PDA (HnsPDA), between May 2017 and May 2018. Echocardiography was done. BNP was measured using enzyme linked immunosorbent assay Results: There was no affection of left ventricular function in either group (LA/Ao ratio, FS, LVESD and LVEDD). PDA size, PFO size and PAP were significantly larger in HsPDA (p<0.001, p=0.001, p<0.001 respectively). Levels of BNP were significantly higher in HsPDA and correlated with the size of the PDA. At a cut-off value of 160.5 pg/ml, BNP had 80.49% sensitivity and 90.62% specificity with a positive predictive value of 91.7% and a negative predictive value of 78.04%, (AUC: 0.923, 95% C.I. 0.837 to 0.973). Conclusion: Levels of BNP in preterm babies with hemodynamically significant PDA rise early in neonatal life and correlate well with the size of the PDA. BNP can be used to screen for this condition. Ventricular dysfunction may not appear in the first 3 days of life.

Early N-Terminal Pro B-Type Natriuretic Peptide (NTproBNP) Plasma Values and Associations with Patent Ductus Arteriosus Closure and Treatment-An Echocardiography Study of Extremely Preterm Infants

The aim was to investigate the association of gestational age (GA), echocardiographic markers and levels of plasma N-terminal pro-B-type natriuretic peptide (NTproBNP) with the closure rate of a haemodynamically significant patent ductus arteriosus (hsPDA). Ninety-eight Swedish extremely preterm infants, mean GA 25.7 weeks (standard deviation 1.3), born in 2012–2014, were assessed with echocardiography and for levels of NTproBNP. Thirty-three (34%) infants had spontaneous ductal closure within three weeks of age. Infants having spontaneous closure at seven days or less had significantly lower NTproBNP levels on day three, median 1810 ng/L (IQR 1760–6000 ng/L) compared with: infants closing spontaneously later, 10,900 ng/L (6120–19,200 ng/L); infants treated either with ibuprofen only, 14,600 ng/L (7740–28,100 ng/L); or surgery, 32,300 ng/L (29,100–35,000 ng/L). Infants receiving PDA surgery later had significantly higher NTproBNP values on day three than other infants. Day three NTproBNP cut-off values of 15,001–18,000 ng/L, predicted later PDA surgery, with an area under the curve in ROC analysis of 0.69 (0.54–0.83). In conclusion, the spontaneous PDA closure rate is relatively high in extremely preterm infants. Early NTproBNP levels can be used with GA in the management decisions of hsPDA.

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.

Exploring the NT-proBNP expression in Premature Infants with Patent Ductus Arteriosus (PDA) by Echocardiography

Objectives:

To investigate the correlation between echocardiographic indicators and the expression level of N-terminal pro-brain natriuretic peptide (NT-proBNP) in premature infants (PIs) with patent ductus arteriosus (PDA) and the value of NT-proBNP in diagnosing symptomatic PDA (sPDA) in PIs whose gestational age (GA) was less than 32 weeks.

Methods:

Ninty premature infants were selected as the research objects, including 52 in the non-PDA group and 38 in the PDA group (26 sPDA cases and 12 cases with asymptomatic PDA (asPDA)) from February 2019 to March 2020. The general information of these infants was recorded, including gender, delivery method, maternal infection, and serum NT-proBNP level on the 3rd day after birth. They were screened by echocardiographic indicators under an artificial intelligence convolutional neural network (AI-CNN). The Receiver Operating Characteristic (ROC) curves were illustrated to decide serum NT-proBNP expression levels, thereby determining specificity and sensitivity of sPDA and the correlation between serum sPDA NT-proBNP expression and echocardiographic indicators.

Results:

The expression level of serum NT-proBNP in the sPDA group was greater than that in the asPDA group and the non-PDA group (P<0.001). The serum NT-proBNP expression level was positively correlated with the diameter of the ductus arteriosus in the sPDA group (r=0.462, P<0.001); it was also positively correlated with the ratio of left atrium/aorta (LA/AO) (r=0.573, P<0.001), but was not correlated with left ventricular ejection fraction (LVEF) (r=-0.015, P=0.747).

Conclusion:

The combination of serum NT-proBNP expression and echocardiography had clinical values in early diagnosis of PDA.

Patent ductus arteriosus, systemic NT-proBNP concentrations and development of bronchopulmonary dysplasia in very preterm infants: retrospective data analysis from a randomized controlled trial

BACKGROUND

Patent ductus arteriosus (PDA) is a common complication in very preterm infants. It is known that there is an association between PDA and development of bronchopulmonary dysplasia (BPD) or death before the postmenstrual age (PMA) of 36 weeks, but this association remains one of the most controversial aspects of the problem. The study aimed to evaluate the relationship between PDA, serum NT-proBNP levels at 2-3 and 8-9 days of life, and BPD/death in very preterm infants.

METHODS

Data of 52 preterm infants with a gestational age < 32 weeks, chronological age < 72 h, and PDA diameter > 1.5 mm, enrolled in a randomized controlled trial, were used for the retrospective analysis. All patients underwent daily echocardiographic and two serum NT-proBNP measurements within the first 10 days after birth. Two groups of infants were formed retrospectively at PMA of 36 weeks depending on the outcome, BPD (n = 18)/death (n = 7) or survival without BPD (n = 27). Receiver operator characteristic (ROC) curve was used to evaluate the predictive performance of serum NT-proBNP levels for BPD/death occurrence.

RESULTS

The percentage of infants who received pharmacological treatment for PDA did not differ between the groups. Based on the area under the ROC curve, serum NT-proBNP levels on the 2-3 day of life (AUC = 0.71; 95% confidence interval (CI): 0.56-0.9; p = 0.014)) and on the 8-9 day of life (AUC = 0.76; 95% CI: 0.6-0.9; p = 0.002) could reliably predict BPD/death in very preterm infants who had PDA diameter > 1.5 mm in the first 72 h of life. Hemodynamically significant PDA (hsPDA) was significantly more often detected in newborns with BPD/death, however, treatment of infants with hsPDA did not reduce the incidence of BPD/death.

CONCLUSIONS

In very preterm infants with PDA > 1.5 mm at the age of 24-48 h, serum NT-proBNP concentration could reliably predict the development of BPD or death, regardless of the persistence of PDA, with the highest diagnostic value at 8-9 days.

TRIAL REGISTRATION

This study is registered in ClinicalTrials.gov - NCT03860428 on March 4, 2019.

Management of Patent Ductus Arteriosus in Premature Infants in 2020

The patent ductus arteriosus (PDA) is the most commonly found cardiac condition in neonates. While there have been several studies and thousands of publications on the topic, the decision to treat the PDA is still strongly debated among cardiologists, surgeons, and neonatologists. This is in part due to the shortage of long-term benefits with the interventions studied. Practice variations still exist within sub-specialties and centers. This article briefly summarizes the history, embryology and histology of the PDA. It also succinctly discusses the hemodynamic significance of a PDA which builds the framework to review all the available literature on PDA closure in premature infants, though not a paradigm shift just yet; it introduces transcatheter PDA closure (TCPC) as a possible armament to the clinician for this age-old problem.

Predictive Value of Blood N-Terminal Pro-Brain Natriuretic Peptide Concentrations for Early Patent Ductus Closure in Very Preterm Infants

Objectives

It has been shown that blood concentrations of NT-proBNP may be useful in identifying preterm infants at risk of hemodynamically significant patent ductus arteriosus and its complications. The aim of the study was to assess predictive value of serum NT-proBNP levels for early ductus arteriosus (DA) closure in very preterm newborns.

Methods

Fifty-two infants <32 weeks’ gestation aged <72 hours with patent ductus arteriosus (PDA) diameter >1.5 mm were involved in a randomized study. Twenty-seven (52%) of them were treated with ibuprofen or paracetamol starting within the first 3 days of life. Expectant management was applied to 25 (48%) infants. All patients underwent planned echocardiographic (daily) and two serum NT-proBNP measurements within the first 10 days after birth. Depending on the DA closure within the first 10 days of life, 2 groups of patients were formed retrospectively, with closed (n = 30) or patent (n = 22) DA by this age.

Results

In the first 10 days of life, DA closure occurred in 19 (70%) treated infants and in 11 (44%) infants managed expectantly (p > 0,05). Initial concentrations of NT-proBNP were significantly higher in infants that had patent ductus arteriosus (PDA) at 10 days of life. By the eighth day, median NT-proBNP values in both groups significantly decreased but remained considerably higher in newborns with PDA. NT-proBNP serum concentrations on the second day of life could reliably predict DA closure within the first 10 days after birth in treated babies (the AUC was significant 0.81 [95% CI: 0.58–1.03], p < 0.05) but not in infants who were managed expectantly.

Conclusions

Serum NT-proBNP concentrations on the second day of life could reliably predict early PDA closure in treated but not in expectantly managed very preterm infants.

Serum N-Terminal Pro-B-Type Natriuretic Peptide as a Biomarker of Critical Pulmonary Stenosis in Neonates

Objectives: To determine the efficacy of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in predicting critical pulmonary stenosis (CPS) in neonates. Methods: All neonates with pulmonary stenosis (PS) admitted to the neonatal intensive care unit of Xinhua Hospital from October 2014 to December 2020 were retrospectively reviewed. Infants with serum NT-proBNP levels measured within 48 h after birth were enrolled and divided into CPS and non-CPS groups. Serum NT-proBNP levels and cardiac Doppler indices were compared between the two groups. Correlations were determined using the Spearman's rank correlation coefficient. Receiver operator characteristic curve analysis was used to explore the predictive value of NT-proBNP for identifying neonatal CPS. Results: Among 96 infants diagnosed with PS by echocardiography, 46 were enrolled (21 and 25 in the non-CPS and CPS groups, respectively). Serum NT-proBNP levels were significantly higher in the CPS group than in the non-CPS group [3,600 (2,040-8,251) vs. 1,280 (953-2,386) pg/ml, P = 0.003]. Spearman's analysis suggested a positive correlation between Ln(NT-proBNP) levels and the transvalvular pulmonary gradient (r = 0.311, P = 0.038), as well as between Ln(NT-proBNP) levels and pulmonary artery velocity (r = 0.308, P = 0.040). Receiver operating characteristic curve analysis showed that a cutoff serum NT-proBNP level of 2,395 pg/ml yielded a 66.7 and 78.9% sensitivity and specificity for identifying CPS, respectively. The area under the curve was 0.784 (95% CI, 0.637-0.931). A positive correlation was found between Ln(NT-proBNP) and length of hospital stay (r = 0.312, P < 0.05). Conclusion: Serum NT-proBNP level was positively correlated with PS severity and could be used as a biomarker to identify CPS in neonates.

Development of a Nomogram for Moderate-to-Severe Bronchopulmonary Dysplasia or Death: Role of N-Terminal Pro-brain Natriuretic Peptide as a Biomarker

Objectives: This study aimed to explore the clinical value of N-terminal pro-brain natriuretic peptide (NT-proBNP) in predicting moderate-to-severe bronchopulmonary dysplasia (BPD)/death, and to establish an effective clinical predictive nomogram. Methods: We retrospectively analyzed very low birth weight infants (VLBWs) with gestational age ≤ 32 weeks. The NT-proBNP values were determined on the 1st, 3rd, 7th, 14th, 21st, and 28th days after birth. The correlation between NT-proBNP level and moderate-to-severe BPD/death was evaluated. Receiver operating characteristic (ROC) curve analysis was used to evaluate the prediction ability. Then, we used multivariable logistic regression to build the prediction model and nomogram, and calibration of the model was assessed by calibration curve. Results: In total, 556 VLBWs were involved, among whom 229 developed BPD (mild: n = 109; moderate: n = 68; severe: n = 52) and 18 died. The NT-proBNP level in the moderate-to-severe BPD/death group was significantly higher than that in the no-to-mild BPD group from the 3rd to 28th day (P < 0.001). When the natural logarithm of the serum NT-ProBNP level increased by 1 unit at day 7 (±2 days) of life, the risk of moderate and severe BPD/death was the highest (OR = 3.753; 95% CI: 2.984~4.720), and ROC analysis identified an optimal cutoff point of 3360 ng/L (sensitivity: 80.0%; specificity: 86.2%; AUC: 0.861). After adjusting for confounding factors, the level of NT-proBNP at day 7 (±2 days) of life still had important predictive value for the development of moderate-to-severe BPD/death, significantly improving the predictive ability of the model. Conclusion: The level of NT-proBNP at day 7 (±2 days) of life can be used as an early promising biomarker for VLBWs to develop moderate-to-severe BPD/death. We constructed an early predictive nomogram to help clinicians identify high-risk populations.

Evaluation of Circulating Cardiovascular Biomarker Levels for Early Detection of Congenital Heart Disease in Newborns in Sweden

IMPORTANCE

Congenital heart disease (CHD) is the most common congenital malformation in humans worldwide. Circulating cardiovascular biomarkers could potentially improve the early detection of CHD, even in asymptomatic newborns.

OBJECTIVES

To assess the performance of a dried blood spot (DBS) test to measure the cardiovascular biomarker amino terminal fragment of the prohormone brain-type natriuretic peptide (NT-proBNP) levels in newborns and to compare DBS with standard EDTA analysis in control newborns during the first week of life.

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic study was conducted in a single regional pediatric service in southern Sweden. Healthy, term neonates born between July 1, 2018, and May 31, 2019, were prospectively enrolled and compared against retrospectively identified newborns with CHD born between September 1, 2003, and September 30, 2019. Neonates who required inpatient treatment beyond the standard postnatal care were excluded.

EXPOSURE

New DBS test for NT-proBNP quantification in newborns that used 3 μL of blood vs the current screening standard.

MAIN OUTCOMES AND MEASURES

Performance of the new test and when combined with pulse oximetry screening was measured by receiver operating characteristic curve analysis. Performance of the new test and EDTA screening was compared using Pearson linear correlation analysis.

RESULTS

The DBS samples of 115 neonates (81 control newborns and 34 newborns with CHD, of whom 63 were boys [55%] and the mean [SD] gestational age was 39.6 [1.4] weeks) were analyzed. The new NT-proBNP test alone identified 71% (n = 24 of 34) of all CHD cases and 68% (n = 13 of 19) of critical CHD cases as soon as 2 days after birth. Detection of any CHD type improved to 82% (n = 28 of 34 newborns) and detection of critical CHD improved to 89% (n = 17 of 19 newborns) when combined pulse oximetry screening and NT-proBNP test results were used. Performance of the NT-proBNP test was excellent when control newborns were matched to newborns with CHD born between July 1, 2018, and May 31, 2019 (area under the curve, 0.96; SE, 0.027; 95% CI, 0.908-1.0; asymptotic P < .05).

CONCLUSIONS AND RELEVANCE

This study found that NT-proBNP assay using minimal DBS samples appears to be timely and accurate in detecting CHD in newborns and to discriminate well between healthy newborns and newborns with various types of CHD. This finding warrants further studies in larger cohorts and highlights the potential of NT-proBNP to improve neonatal CHD screening.

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.

Circulating Forms of B-Type Natriuretic Peptide in Very Preterm Infants

BACKGROUND

B-type natriuretic peptide (BNP) is a cardiac hormone released with an N-terminal fragment (NTproBNP) under conditions of ventricular pressure or volume overload. BNP has been proposed for use as a biomarker of cardiac dysfunction in premature infants in the setting of hemodynamically significant patent ductus arteriosus (HsPDA) and bronchopulmonary dysplasia (BPD). In adult settings the presence of proBNP and glycosylated isoforms may affect assay interpretation. However, there are limited data on how immature preterm physiology may affect BNP or NTproBNP levels and no published data on post-translational BNP processing in premature infants.

METHODS

Pooled serial plasma samples from preterm infants born at less than 30 weeks gestation were analyzed for BNP congeners using Luminex® assay and high performance liquid chromatography. Samples were grouped according to clinical status: Group 1, no HsPDA and no BPD, Group 2 HsPDA and no/mild BPD, Group 3 HsPDA and moderate/severe BPD.

RESULTS

Plasma from 15 infants was analyzed, and across all three groups NTproBNP predominated with minimal amounts of other isoforms; no glycosylation was detected.

CONCLUSIONS

NTproBNP appears to be the predominant isoform across each of our clinical groups in our pooled sample analysis with no evidence of significant glycosylation. This suggests NTproBNP is likely to be a robust marker in this clinical setting.

Natriuretic peptides in bronchopulmonary dysplasia: a systematic review

OBJECTIVES

To systematically review the diagnostic accuracy of brain natriuretic peptide (BNP) and amino-terminal pro-B-type natriuretic peptide (NT-proBNP) in bronchopulmonary dysplasia (BPD) and BPD-pulmonary hypertension (PH).

STUDY DESIGN

PubMed, Embase, the Web of Science, and the Cochrane Library were searched in March 2019. We included studies that evaluated BNP or NT-proBNP in preterm neonates as a marker for predicting BPD, BPD or death, and BPD-PH.

RESULTS

Nine studies evaluating NT-proBNP/BNP were included. The quality of evidence was low, using GRADE criteria. The diagnostic accuracy of NT-proBNP and BNP for diagnosing BPD-PH showed high sensitivity and specificity in infants with BPD. Lower sensitivities and specificities of NT-proBNP and BNP were reported for predicting BPD, BPD or death, compared with that for BPD-PH.

CONCLUSIONS

Low quality evidence suggests that NT-proBNP and BNP have adequate diagnostic accuracy for diagnosing and monitoring BPD-PH and may be used to triage patients to receive an echocardiogram.

Role of NT-proBNP in the prediction of moderate to severe Bronchopulmonary Dysplasia in preterm infants

OBJECTIVE

The objective of the study was to determine the clinical utility of brain natriuretic peptide (NT-proBNP) for prediction of moderate to severe bronchopulmonary dysplasia (BPD). We hypothesized that elevated NT-proBNP levels at 4 weeks of postnatal age may predict the severity of BPD in preterm infants.

STUDY DESIGN

The study design was a prospective observational study. The research team enrolled and followed a cohort of 70 infants with gestational age less than or equal to 30 weeks. The plasma NT-proBNP levels were measured at the postnatal day 28th. We further followed and categorized infants into two groups. Infants with no or mild BPD (Group 1) and infants with moderate or severe BPD (Group 2). We compared plasma NT-proBNP levels at 28th day of postnatal life between Groups 1 and 2. The difference in NT-proBNP levels on day 28th between groups was used to predict the severity of BPD.

RESULTS

Plasma NT-proBNP was significantly elevated in Group 2 compared with Group 1, median (IQR) of 845 pg/mL (553, 1632) compared with 726 pg/mL (391, 923), P = 0.02. NT-proBNP had a fair predictive accuracy (C statistics of 0.68) to determine moderate to severe BPD.

CONCLUSION

NT-proBNP may be a useful biomarker in conjunction with clinical factors as a predictor of severe BPD. For future directions, the trend of NT-proBNP in infants with BPD may have clinical significance in monitoring of the disease.

Serum and Urinary N-Terminal Pro-brain Natriuretic Peptides as Biomarkers for Bronchopulmonary Dysplasia of Preterm Neonates

Bronchopulmonary dysplasia (BPD) is a common cause of respiratory illness in preterm newborns with high morbidity and mortality rates. At present, there are no early prognostic biomarkers that can be used in clinical practice to predict the development of BPD. In this review, we critically appraise evidence regarding the use of serum N-terminal pro-brain natriuretic peptide (NTproBNP) levels as a biomarker for BPD in neonates. Furthermore, we summarize studies assessing the feasibility of urinary NTproBNP levels as a non-invasive method to predict BPD in preterm infants. Multiple studies reported a strong association between NTproBNP serum levels and the onset of BPD. For urinary NTproBNP there is scarce evidence showing an association with BPD. Given the promising data obtained by preliminary studies, further assessment of this biomarker in both serum and urine is needed. Standardized reference values should be defined before conducting any further clinical studies.

Early Urinary Metabolomics in Patent Ductus Arteriosus Anticipates the Fate: Preliminary Data

Introduction: In premature neonates, the persistence of hemodynamically significant ductus arteriosus (hsPDA) can be associated with short- and long-term consequences, impairing their outcome. The correct strategy of management for such condition is under debate, especially regarding contraindications and/or side effects. In recent years, metabolomics was applied to several perinatal, pediatric, and adult conditions to investigate potential biomarkers of disease, which have become useful for early diagnosis and/or therapeutic management. Aim of the Study: The main purpose of our exploratory study was to asses, through ¹H-NMR metabolomics analysis of urinary samples at birth, possible metabolic pathways differentiating, with a significant predictive power, those preterm neonates who will subsequently develop hsPDA and neonates of comparable gestational age (GA) who will undergo spontaneous ductal closure or the persistence of an irrelevant PDA (no-hsPDA). Moreover, we investigated potential prenatal or perinatal clinical factors potentially influencing the development of hsPDA. Materials and Methods: We enrolled n = 35 preterm neonates with GA between 24 and 32 weeks; urinary samples were collected within the first 12 h of life. Patients were closely monitored regarding intensive care, respiratory support, fluid balance and administered drugs; an echocardiogram was performed at 48-72 h. Results: Our results reported a significant correlation between lower GA at birth and the development of hsPDA. Moreover, neonates with GA ≤ 30w developing hsPDA were characterized by lower Apgar scores at 1' and 5', higher rates of perinatal asphyxia, higher need of delivery room resuscitation and subsequent surfactant administration. Interestingly, metabolomics analysis at birth detected a clear separation between the ¹H-NMR urinary spectra of subjects GA ≤ 30w not developing hsPDA (n = 19) and those of subjects born at GA ≤ 30w in which hsPDA was confirmed at 48-72 h of life (n = 5). Conclusions: This is the first study applying metabolomics to investigate the PDA condition. Although preliminary and conducted on a limited sample, our results reveal that metabolomics could be a promising tool in the early identification of hsPDA, potentially superior to the clinical or laboratory predictive tools explored to date and even to the clinical observations and correlations in our sample, through the detection of specific urinary metabolites.

Left Ventricular Diastolic Dysfunction and Diastolic Heart Failure in Preterm Infants

Diastolic dysfunction is primarily an echocardiographic diagnosis. Its clinical counterpart is diastolic heart failure, where the heart has difficulty to fill at normal pressure and the patient develops signs of pulmonary edema. Although diastolic dysfunction is common in adults, limited information is available in preterm infants. The aim of this study is to explore left ventricular diastolic dysfunction and diastolic heart failure in preterm infants and describe clinical manifestations in this population. This is a retrospective observational study in preterm infants < 30 weeks' gestation who received an echocardiography in the first 4 weeks after birth. Diastolic dysfunction was graded using a population-specific adapted version of the adult recommendations for the evaluation of left ventricular diastolic function by echocardiography. Left ventricular diastolic dysfunction was absent, indeterminate, and definite in 82%, 14%, and 4% of the 168 echocardiograms analyzed, and is associated with increased respiratory signs and respiratory deterioration at 48 h before echocardiogram. In seven infants, diastolic heart failure was diagnosed with both ultrasound and clinical signs. The cumulative risk of diastolic dysfunction increased with the increasing postnatal age and a patent ductus arteriosus. Evidence of left ventricular diastolic dysfunction on echocardiography is relatively common in preterm infants, while the left ventricular diastolic heart failure is less frequent. Prolonged exposure to volume load was the most common cause.

Early prediction of spontaneous Patent Ductus Arteriosus (PDA) closure and PDA-associated outcomes: a prospective cohort investigation

BACKGROUND

Patent ductus arteriosus (PDA), the most commonly diagnosed cardiovascular condition in preterm infants, is associated with increased mortality and harmful long-term outcomes (chronic lung disease, neurodevelopmental delay). Although pharmacologic and/or interventional treatments to close PDA likely benefit some infants, widespread routine treatment of all preterm infants with PDA may not improve outcomes. Most PDAs close spontaneously by 44-weeks postmenstrual age; treatment is increasingly controversial, varying markedly between institutions and providers. Because treatment detriments may outweigh benefits, especially in infants destined for early, spontaneous PDA closure, the relevant unanswered clinical question is not whether to treat all preterm infants with PDA, but whom to treat (and when). Clinicians cannot currently predict in the first month which infants are at highest risk for persistent PDA, nor which combination of clinical risk factors, echocardiographic measurements, and biomarkers best predict PDA-associated harm.

METHODS

Prospective cohort of untreated infants with PDA (n=450) will be used to predict spontaneous ductal closure timing. Clinical measures, serum (brain natriuretic peptide, N-terminal pro-brain natriuretic peptide) and urine (neutrophil gelatinase-associated lipocalin, heart-type fatty acid-binding protein) biomarkers, and echocardiographic variables collected during each of first 4 postnatal weeks will be analyzed to identify those associated with long-term impairment. Myocardial deformation imaging and tissue Doppler imaging, innovative echocardiographic techniques, will facilitate quantitative evaluation of myocardial performance. Aim1 will estimate probability of spontaneous PDA closure and predict timing of ductal closure using echocardiographic, biomarker, and clinical predictors. Aim2 will specify which echocardiographic predictors and biomarkers are associated with mortality and respiratory illness severity at 36-weeks postmenstrual age. Aim3 will identify which echocardiographic predictors and biomarkers are associated with 22 to 26-month neurodevelopmental delay. Models will be validated in a separate cohort of infants (n=225) enrolled subsequent to primary study cohort.

DISCUSSION

The current study will make significant contributions to scientific knowledge and effective PDA management. Study results will reduce unnecessary and harmful overtreatment of infants with a high probability of early spontaneous PDA closure and facilitate development of outcomes-focused trials to examine effectiveness of PDA closure in "high-risk" infants most likely to receive benefit.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03782610. Registered 20 December 2018.

Base excess and hematocrit predict response to indomethacin in very low birth weight infants with patent ductus arteriosus

Background

The treatment of patent ductus arteriosus (PDA) in very low birth weight (VLBW) infants remains a challenge. The ability to predict which infants will respond to indomethacin could spare some from the risks of unnecessary medications. Our objective was to determine if indicators of acid-base homeostasis could predict response to indomethacin treatment for ductal closure, and thus help guide treatment decisions.

Methods

We performed a retrospective analysis of medical records of VLBW (< 1500 g) neonates with hemodynamically significant PDA born at our institution between January 2009 and December 2012; all infants included in the study were treated with indomethacin for ductal closure within the first 2 weeks of life. We extracted data for a number of clinical variables including gestational age, birth weight, blood chemistries, surfactant use, hematocrit, and blood gas parameters. Our primary outcome measure was successful closure of PDA following the first round of indomethacin. Using variables that were significant on initial testing, we created multivariable regression models to determine the independent association of selected variables with indomethacin response.

Results

Of the 91 infants included in the study, 62 (68%) responded to the first course of indomethacin with successful ductal closure. Multivariable regression modeling revealed that both base excess and hematocrit were independently associated with indomethacin response; odds of PDA closure increased with increasing base excess (OR [odds ratio]: 1.81; 95% confidence interval [CI]: 1.36–2.60) and increasing hematocrit (OR: 1.21; 95% CI: 1.01–1.45). The optimal cutoff value for base excess was − 4.56, with a sensitivity of 96.8% (95% CI: 89–100) and specificity of 79.3% (95% CI: 60–92); optimal cutoff value for hematocrit was 40, with 69.4% sensitivity (95% CI: 56–80) and 65.5% specificity (95% CI: 46–82).

Conclusions

Base excess and hematocrit may be independent predictors of indomethacin response in VLBW infants with PDA. Low-cost and readily accessible, acid-base indicators such as base excess could help guide treatment decisions.

Electronic supplementary material

The online version of this article (10.1186/s13052-019-0706-y) contains supplementary material, which is available to authorized users.

Oral ibuprofen is superior to oral paracetamol for patent ductus arteriosus in very low and extremely low birth weight infants

Paracetamol (acetaminophen) has been proposed as an alternative medication for closing hemodynamically significant patent ductus arteriosus (PDA). However, the clinical outcomes remain inconclusive in very low birth weight (VLBW) and extremely low birth weight (ELBW) infants.The aim of this study was to compare the efficacy and safety of oral paracetamol and ibuprofen for pharmacological closure of PDA in premature infants from a real-world study.This retrospective study enrolled 255 preterm infants with birthweights of ≤1.5 kg, and echocardiographically confirmed significant PDA. Subjects were classified into 3 groups: Group I (standard-dose ibuprofen group) received 10 mg/kg oral ibuprofen followed by 5 mg/kg/day for 2 days. Group II (high-dose ibuprofen group) received 10 mg/kg/day oral ibuprofen for 3 days. Group III (paracetamol group) received 15 mg/kg/6 h oral paracetamol for 3 days.On day 9 after medication start, PDA closure was achieved in 61 (71.7%) patients assigned to the high-dose ibuprofen group, (63.8%) in the standard-dose ibuprofen group, and 33 (37.9%) of those in the oral paracetamol group (P <.001). Oral standard-dose ibuprofen was more effective than oral paracetamol (P = .001). The ductus closed faster in the high-dose ibuprofen group than in the standard-dose group (median closure time 3.9 ± 1.0 versus 4.4 ± 1.0 days, P = .009). Total bilirubin significantly increased in the high-dose ibuprofen group (P = .02). No gastrointestinal, renal, or hematological adverse effects were reported. Subgroup analyses indicated paracetamol was minimally effective in ELBW infants (PDA closure 13%).This study demonstrated that paracetamol may be a poor medical alternative for PDA management in VLBW and ELBW infants. High dosage ibuprofen was associated with a faster clinical improvement and higher rate of PDA closure.

NT-proBNP as an Early Marker of Diastolic Ventricular Dysfunction in Very-Low-Birth-Weight Infants

The objective is to examine the correlation between plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and tissue Doppler imaging (TDI) echocardiographic parameters in the first 28 days of life in very-low-birth-weight infants (VLBWI). VLBWI admitted to the Neonatal Intensive Care Unit (NICU) at Hospital Puerta del Mar, Spain, from January 2015 to January 2017 were prospectively enrolled. Weekly determination of plasma NT-proBNP (pg/mL), and echocardiograms were done during the first 28 days of life. 101 preterm infants with a mean GA of 28.85 weeks (± 1.85 SD) and mean birth weight of 1152 g (± 247.4 SD) were included. A total of 483 echocardiograms and 139 NT-proBNP determinations were performed. We found a negative correlation between plasma NT-proBNP levels and diastolic velocities: mitral A' (ρ = - 0.15, p = 0.04), mitral E' (ρ = - 0.17, p = 0.02), tricuspid A' (ρ = - 0.20, p = 0.006), tricuspid E' (ρ = - 0.24, p = 0.0009). In the first 24 h of life, NT-proBNP levels were strongly correlated with mitral A' and E' velocities in patients with no patent ductus arteriosus (PDA) (ρ = - 0.75, p = 0.04). In preterm patients, elevated NT-proBNP levels are related to worse diastolic myocardial function. In the first 24 h, this correlation is much stronger in the absence of PDA.

NTproBNP is a useful early biomarker of bronchopulmonary dysplasia in very low birth weight infants

Bronchopulmonary dysplasia (BPD) is a severe complication of prematurity that impacts survival and neurodevelopment. Currently, no early marker exists which could help clinicians identify which preterm infants will develop BPD. Given the evidence that NTproBNP is elevated in children with BPD, we hypothesized that it could be used as an early marker of BPD development. We conducted a prospective cohort study including very low birth weight infants (VLBWI) admitted to our NICU between January 2015 and January 2017 in which we determined serial NTproBNP levels on days 1 and 3 and then weekly, until 49 days of life. A total of 101 patients were recruited (mean birth weight 1152 g (SD 247.5), mean gestational age 28.9 weeks (SD 1.9)). NTproBNP levels differed among infants who did and did not develop BPD from 14 to 35 days of life with the greatest difference on day 14 of life (non-BPD group (n = 86): 1155 (IQR 852-1908) pg/mL, BPD (n = 15): 9707 (IQR 3212-29,560) pg/mL; p = 0.0003). The presence of HsPDA did not account for higher levels of NTproBNP at day 14 (p = 0.165). We calculated an optimal cutoff point of 2264 pg/mL at 14 days of life (sensitivity 100%, specificity 86% and AUC 0.93).Conclusions: NTproBNP at 14 days of life could be used as an early marker of later BPD development in VLBWI. What is Known: • Children with BPD have elevated NTproBNP levels, which are related to the severity of BPD and the development of pulmonary hypertension. What is New: • NTproBNP at 14 days of life is higher in those who later develop BPD, regardless of the presence of hemodynamically significant patent ductus arteriosus. • A calculated cutoff point of 2264 pg/mL of NTproBNP at 14 days has a sensitivity of 100% and specificity of 86% in the prediction of BPD.

Practice for preterm patent ductus arteriosus; focusing on the hemodynamic significance and the impact on the neonatal outcomes

Hemodynamically significant preterm patent ductus arteriosus (PDA) affects mortality; comorbidities such as necrotizing enterocolitis, intraventricular hemorrhage, and bronchopulmonary dysplasia; and adverse long-term neurodevelopmental outcomes in preterm infants, particularly in very low birth weight infants. However, recent studies have indicated that there is no consensus on the causal relationship between PDA and neonatal outcomes, the benefit of PDA treatment, the factors guiding the need for treatment, and optimal treatment strategies. Such uncertainty has resulted in wide variations in practice for treating preterm PDA between units, regions, and nations. Nowadays, there has been a paradigm shift to more conservative treatment for preterm PDA, and suggestions regarding selective management of preterm PDA considering risk factors and hemodynamic significance are increasing. Neonatologist-performed echocardiography and advances in modalities to assess hemodynamic significance such as biologic markers and near-infrared spectroscopy also help improve the efficacy of selective treatment of preterm PDA.

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.

Turkish Neonatal Society guideline on the management of patent ductus arteriosus in preterm infants

Ductus arteriosus is a physiologic phenomenon in utero and it closes spontaneously in term babies. The closure is problematic in preterm infants due to the intrinsic properties of the preterm ductus arteriosus tissue. Although patent ductus arteriosus has been reported to be associated with many adverse outcomes in this population, treatment has not led to a decrease in outcomes such as bronchopulmonary dysplasia. Treatment modalities also have their own risks and restrictions. The aim of the "Turkish Neonatal Society guidelines for the management of patent ductus arteriosus in preterm babies" is to standardize the diagnosis and treatment of patent ductus arteriosus in preterm infants by combining the current scientific data and the resources of our country.

Management strategies for the preemie ductus

PURPOSE OF REVIEW

Patent ductus arteriosus (PDA) remains the most common cardiovascular condition afflicting neonates. Despite 5 decades of scientific inquiry pediatric cardiologists and neonatologists still cannot answer the simple question of which PDAs should be treated.

RECENT FINDINGS

Although the volume of the shunt is difficult to calculate, echocardiography, biochemical markers, and clinical exam can provide clues to the magnitude and physiologic consequences of the shunt. Epidemiologic data exists showing a positive relationship between a PDA and numerous morbidities. As a result, for most of the 20th and early 21st century, nearly all PDAs where indiscriminately considered to be hemodynamically significant and attempts to close it where initiated shortly after birth. However, no randomized trials of PDA closure have been able to show significant differences between affected and unaffected groups. In fact, surgical ligation has repeatedly been associated with increased morbidities and worse long-term neurodevelopmental outcomes. As a result, most clinicians favor a strategy of watchful waiting.

SUMMARY

In this review, we aim to summarize the scientific literature, along with some of the contemporary biases, that exist with regards to the pathophysiology, genetics, and treatment strategies for the neonatal PDA.

High-sensitivity troponin T in preterm infants with a hemodynamically significant patent ductus arteriosus

OBJECTIVE

To investigate if a hemodynamically significant patent ductus arteriosus (hsPDA) leads to elevated high-sensitivity troponin T (hsTnT) and NTproBNP levels in serum.

STUDY DESIGN

Infants <34 weeks and <1500 g were prospectively enrolled, except those with major congenital or chromosomal anomalies. An echocardiogram (ECHO) was performed and hsTnT and NTproBNP were measured within 5 days of life and repeated after treatment of hsPDA. Clinical, ECHO, and hsTnT data were analyzed using Student t-test, two proportion z-test, and regression analysis.

RESULTS

Seventy infants were enrolled. Infants in the hsPDA group had lower gestation and birth weight. Mean hsTnT and NTproBNP levels in the hsPDA group were higher compared to the group without an hsPDA, with levels being 251.54 vs 161.6 pg/ml, p < 0.01 for hsTnT and 18181.02 vs 3149.23 pg/ml, p < 0.001 for NTproBNP.

CONCLUSION

HsPDA leads to increased hsTnT and NTproBNP levels in preterm infants without affecting cardiac function.

Association between Furosemide Exposure and Patent Ductus Arteriosus in Hospitalized Infants of Very Low Birth Weight

OBJECTIVE

To evaluate the association between furosemide exposure and patent ductus arteriosus (PDA) in a large, contemporary cohort of hospitalized infants with very low birth weight (VLBW).

STUDY DESIGN

Using the Pediatrix Medical Group Clinical Data Warehouse, we identified all inborn infants of VLBW <37 weeks of gestation discharged from the neonatal intensive care unit after the first postnatal week from 2011 to 2015. We defined PDA as any medical (ibuprofen or indomethacin) or surgical PDA therapy. We collected data up to the day of PDA treatment or postnatal day 18 for infants not diagnosed with PDA. We performed multivariable logistic regression to evaluate the association between PDA and exposure to furosemide.

RESULTS

We included 43 576 infants from 337 neonatal intensive care units, of whom 6675 (15%) underwent PDA treatment. Infants with PDA were more premature and more often exposed to mechanical ventilation and inotropes. Furosemide was prescribed to 4055 (9%) infants. On multivariable regression, exposure to furosemide was associated with decreased odds of PDA treatment (OR 0.72; 95% CI 0.65-0.79). Increasing percentage of days with furosemide exposure was not associated with PDA treatment (OR 1.01; 95% CI 0.97-1.06).

CONCLUSIONS

Furosemide exposure was not associated with increased odds of PDA treatment in hospitalized infants of VLBW. Further studies are needed to characterize the efficacy and safety of furosemide in premature infants.

Factors affecting N-terminal pro-B-type natriuretic peptide levels in preterm infants and use in determination of haemodynamic significance of patent ductus arteriosus

This study aimed to investigate factors affecting N-terminal pro-B-type natriuretic peptide (NTproBNP) in preterm infants and the ability of NTproBNP to predict haemodynamically significant patent ductus arteriosus (HsPDA). Prospective cohort study of 51 infants < 30 weeks gestation. Blood NTproBNP and heart ultrasound were performed on day of life 3, 10, 28 and 36 weeks corrected age. NTproBNP levels analysed for prediction of HsPDA. The effect of gestational age, ventilation, hypoxia, bronchopulmonary dysplasia (BPD), creatinine and haemoglobin levels on NTproBNP levels were investigated. Infants with HsPDA had higher mean (SD) day 3 NTproBNP (1840 pmol/L (1058) versus 178 pmol/L (140) p < 0.001). Receiver operator curves of day 3 NTproBNP for prediction of day 3 and day 10 HsPDA had an area under the curve of 0.98 and 0.94, respectively. A chosen day 3 NTproBNP value of ≥ 287 pmol/L for the prediction of day 3 HsPDA correctly classified 92% (sensitivity 92%, specificity 92%). NTproBNP demonstrated only modest ability to predict severe BPD. Chronological but not gestational age affected NTproBNP. Ventilation, hypoxia and haemoglobin levels did not influence NTproBNP but creatinine level was positively correlated.

CONCLUSION

Day 3 NTproBNP is a useful biomarker to predict HsPDA and may be a valuable tool in future trial design. What is Known: • NTproBNP is a cardiac hormone used to diagnose and monitor cardiac dysfunction in adults and has been shown to be higher in premature infants with haemodynamically significant ductus arteriosus (HsPDA). What is new: • NTproBNP is highly predictive of ultrasound-defined HsPDA and may be a useful tool for further triage • Early NTproBNP higher in infants who develop severe BPD and with renal impairment but not affected by gestational age, recent exposure to hypoxia or haemoglobin levels while late levels unexpectedly higher in those without BPD or HsPDA.

Urinary NT-proBNP levels and echocardiographic parameters for patent ductus arteriosus

OBJECTIVE

Patent ductus arteriosus (PDA) is common in preterm infants and is associated with significant morbidities. B type natriuretic peptide (BNP) is synthesized in the ventricles secondary to volume overload and excreted as urinary N-terminal pro-brain natriuretic peptide (NT-proBNP).

STUDY DESIGN

We report an observational prospective study of 64 preterm infants with birth weight ⩽1000 g. Echocardiographic parameters were obtained from clinical echocardiograms performed in the first week of life. Urinary NT-proBNP/creatinine ratios (pg mg^-1) were measured on the same day of the echocardiograms.

RESULTS

Infants with medium to large PDA (n=39) had significantly higher NT-proBNP/creatinine levels compared with infants with small PDA (n=10) (median (IQ range): 2333 (792-6166) vs 714 (271-1632) pg mg^-1, P=0.01) and compared with infants with no PDA (n=15) (2333 (792-6166) vs 390 (134-1085) pg mg^-1, P=0.0003). Urinary NT-proBNP/creatinine ratios were significantly lower post treatment if PDA closed (n=17), P=0.001 or if PDA became smaller after treatment (n=9), P=0.004. Urinary NT-proBNP/creatinine levels correlated with ductal diameter (P⩽0.0001), but not with LA/Ao ratio (P=0.69) or blood flow velocity through the ductus (P=0.06).

CONCLUSION

Our findings indicate that there is a positive correlation between ductal diameter and urinary NT-proBNP in preterm infants.

N-terminal B-type natriuretic peptide urinary concentrations and retinopathy of prematurity

BackgroundTo validate the findings of a single-center pilot study showing elevated urinary N-terminal B-type natriuretic peptide (NTproBNP) concentrations in preterm infants subsequently developing severe retinopathy of prematurity (ROP) in a multicenter setting across eight European and Middle East countries.MethodsProspective observational study in 967 preterm infants <30 weeks' gestational age assessing the capacity of urinary NTproBNP on days of life (DOLs) 14 and 28 to predict ROP requiring treatment.ResultsUrinary NTproBNP concentrations were markedly elevated in infants who developed ROP requiring treatment (n=94) compared with survivors without ROP treatment (n=837), at both time points (median (interquartile range) DOL14: 8,950 (1,925-23,783) vs. 3,083 (1,193-17,393) vs. 816 (290-3,078) pg/ml, P<0.001) and DOL28 (2,203 (611-4,063) vs. 1,671 (254-11,340) vs. 408 (162-1,126) pg/ml, P<0.001). C-statistic of NTproBNP for treated ROP or death was 0.731 (95% confidence interval 0.654-0.774) for DOL14 and 0.683 (0.622-0.745) for DOL28 (P<0.001). Threshold scores were calculated, potentially enabling around 20% of infants with low NTproBNP scores never to be screened with ophthalmoscopy.ConclusionThere is a strong association between early urinary NTproBNP and subsequent ROP development, which can be used to further refine subgroups of patients with high or low risk of severe ROP.

Individualized ibuprofen treatment using serial B-type natriuretic peptide measurement for symptomatic patent ductus arteriosus in very preterm infants

PURPOSE

Plasma level of B-type natriuretic peptide (BNP), an emerging, sensitive, and specific biomarker of hemodynamically significant patent ductus arteriosus (PDA), rapidly decreases in infants receiving cyclooxygenase inhibitors for ductal closure. We investigated the usefulness of serial BNP measurement as a guide for individual identification of early constrictive responses to ibuprofen in preterm infants with symptomatic PDA (sPDA).

METHODS

Before March 2010, the standard course of pharmacological treatment was initiated with indomethacin (or ibuprofen) and routinely followed by 2 additional doses at intervals of 24 hours. After April 2010, individualized pharmacological treatment was used, starting with the first dose of ibuprofen and withholding additional ibuprofen doses if the BNP concentration was <600 pg/mL and clinical symptoms of PDA improved.

RESULTS

The BNP-guided group received significantly fewer doses of ibuprofen than the standard group did during the first course of treatment and the entire study period. The need for further doses of cyclooxygenase inhibitors and for surgical ligation was not significantly different between the 2 groups. No significant differences were seen in clinical outcomes and/or complications related to sPDA and/or pharmacological treatment.

CONCLUSION

Individualized BNP-guided pharmacological treatment may be used clinically to avoid unnecessary doses of cyclooxygenase inhibitors without increasing the ductal closure failure and the short-term morbidity related to sPDA.

What Is High Enough? Elevated NT-pro-BNP in Decompensated Paroxysmal Supraventricular Tachycardia

Since the late 1980s, elevated atrial natriuretic peptide (ANP) was considered the cause of brisk diuresis in adult patients with paroxysmal supraventricular tachycardia (PSVT). Pro-brain natriuretic peptide (pro-BNP) and related molecules, e.g., N-terminal pro b-type natriuretic peptide (NT-pro-BNP) are known biomarkers of heart failure in adult patients from many causes with probable relevance in children. Perhaps, pro-BNP or related molecules such as NT-pro-BNP are useful in the management of PSVT in infants, thus hastening treatment in children who may otherwise significantly decompensate. Case series of one infant and two neonates presenting with cardiogenic shock and evidence of heart failure are presented. Cardiac monitoring or electrocardiogram (ECG) confirmed the presence of PSVT. Adenosine was administered resulting in successful chemical cardioversion with each case. Significantly elevated NT-pro-BNP levels correlated with heart failure prior to cardioversion. In each case, patients were discharged home with lower NT-pro-BNP levels and maintenance with a β-blocker. Due to documented relationships between elevated pro-BNP level and heart failure in adults, the authors measured the related biomarker NT-pro-BNP in each case, as the relationship could be similar in pediatric PSVT. Based on our experience with children in acute heart failure from other causes, NT-pro-BNP can increase to potentially extreme levels in infants. It appears to correlate with clinical signs of insufficient cardiac output, such as tachycardia, respiratory distress, and moribund appearance. Indeed, in the case series, extremely high NT-pro-BNP values were obtained when the patients appeared moribund from decompensated PSVT. The question arising from these observations is: At what level of elevated NT-pro-BNP, would patients be identified for cardioversion prior to appearance of other signs and symptoms? For each patient within the case series, NT-pro-BNP levels of approximately 20,000 pg/mL were indicative of decompensated heart failure, which was subsequently confirmed by examination of the patient. Further investigation is needed to determine the clinical significance of NT-pro-BNP and related peptides in pediatric patients with PSVT and intermittent PSVT. However, the possibility exists that an increase in NT-pro-BNP and related peptides could be a biomarker for cardiac decompensation after prolonged or intermittent PSVT, thereby shortening the time of diagnosis and intervention, and hence, potentially preventing morbidity, mortality, and extended hospitalization. Additional evidence-based research would help provide biomarker information during PSVT allowing practitioners to more objectively analyze risks.

Patent Ductus Arteriosus in the Preterm Infant: Diagnostic and Treatment Options

BACKGROUND

The incidence of hemodynamically significant patent ductus arteriosus (hsPDA) increases with decreasing gestational age and is associated with many common morbidities of extreme prematurity. Controversies remain surrounding the definition of hsPDA, the population of infants requiring treatment, the appropriate timing and method of treatment, and the outcomes associated with PDA and its therapies.

PURPOSE

This integrative literature review focuses on diagnostic and treatment recommendations derived from the highest levels of evidence.

SEARCH STRATEGY

PubMed and CINAHL were searched using key words "neonatal" and "patent ductus arteriosus" to discover the highest levels of evidence surrounding diagnosis, treatment methods, and outcomes.

FINDINGS/RESULTS

The lack of consensus surrounding the diagnosis and clinical significance of PDA hinders meta-analysis across studies and confounds understanding of appropriate management strategies. Novel biomarkers, pharmaceutical choices, and transcatheter closure methods are expanding diagnostic and treatment options.

IMPLICATIONS FOR PRACTICE

Infants weighing less than 1000 g are at highest risk. Prophylactic closure is no longer recommended, although early asymptomatic therapy is still preferred by some to avoid prolonged pulmonary overcirculation or decreased renal and gut perfusion. Conservative treatment measures such as fluid restriction and diuretic administration have not consistently proven effective and are in some instances detrimental. Cyclooxygenase inhibitors are effective but have adverse renal and mesenteric effects. Oral ibuprofen is associated with lower instance of necrotizing enterocolitis.

IMPLICATIONS FOR RESEARCH

Well-defined staging criteria would aid in comparison and meta-analysis. Trials that include a control group that receives no therapy may help separate the outcomes associated with prematurity from those associated with PDA.

Development of a Diagnostic Clinical Score for Hemodynamically Significant Patent Ductus Arteriosus

There is no consensus about the hemodynamic significance and, therefore, the need to treat a persistent ductus arteriosus in preterm newborns. Since the diagnosis of a hemodynamically significant persistent ductus arteriosus (hsPDA) is made by a summary of non-uniform echo-criteria in combination with the clinical deterioration of the preterm neonate, standardized clinical and ultrasound scoring systems are needed. The objective of this study was the development of a clinical score for the detection and follow-up of hsPDA. In this observational cohort study of 154 preterm neonates (mean gestational age 28.1 weeks), clinical signs for the development of hsPDA were recorded in a standardized score and compared to echocardiography. Analyzing the significance of single score parameters compared to the diagnosis by echocardiography, we developed a short clinical score (calculated sensitivity 84% and specificity 80%). In conclusion, this clinical diagnostic PDA score is non-invasive and quickly to implement. The continuous assessment of defined clinical parameters allows for a more precise diagnosis of hemodynamic significance of PDA and, therefore, should help to detect preterm neonates needing PDA-treatment. The score, therefore, allows a more targeted use of echocardiography in these very fragile preterm neonates.

The Utility of Brain Natriuretic Peptide in Pediatric Cardiology: A Review

OBJECTIVE

The aim of this article is to evaluate the clinical utility of brain natriuretic peptide in pediatric patients, examining the diagnostic value, management, and prognostic relevance, by critical assessment of the literature.

DATA SOURCES

In December 2015, a literature search was performed (PubMed access to MEDLINE citations; http://www.ncbi.nlm.nih.gov/PubMed/) and included these Medical Subject Headings and text terms for the key words: "brain natriuretic peptide," "amino-terminal pro-brain natriuretic peptide," "children," "neonate/s," "newborn/s," "infant/s," and "echocardiography."

STUDY SELECTION

Each article title and abstract was screened to identify relevant studies. The search strategy was limited to published studies in English language concerning brain natriuretic peptide/amino-terminal pro-brain natriuretic peptide in pediatric patients.

DATA EXTRACTION

Data on age, gender, type of clinical condition, brain natriuretic peptide assay method, cardiac function variables evaluated by echocardiography, and prognosis were extracted.

DATA SYNTHESIS

Brain natriuretic peptide reference values in healthy newborns, infants, and children are presented. Brain natriuretic peptide diagnostic accuracy in newborns, infants, and children suspected to have congenital heart defects is discussed, and brain natriuretic peptide prognostic value reviewed. The data suggest that the determination of brain natriuretic peptide levels improves the diagnostic accuracy in the assessment of heart disease in the pediatric population. Brain natriuretic peptide assay may increase the accuracy of neonatal screening programs for diagnosing congenital heart defects. Echocardiographic variables correlated to brain natriuretic peptide levels. Additionally, brain natriuretic peptide levels predicted adverse outcomes in the postoperative period.

CONCLUSIONS

Brain natriuretic peptide assessment is a reliable test to diagnose significant structural or functional cardiovascular disease in children. In the integrated follow-up of these cases, several physiologic and clinical variables must be considered; brain natriuretic peptide may be an additional helpful marker. Nevertheless, larger prospective studies are warranted to elucidate the true prognostic value of brain natriuretic peptide in pediatric patients.

Correlation of B-type natriuretic peptide levels and echocardiographic parameters in preterm infants with patent ductus arteriosus

Purpose

This study aimed to evaluate the correlation, according to postnatal age, between plasma B-type natriuretic peptide (BNP) levels and echocardiographic parameters for the assessment of patent ductus arteriosus (PDA) in preterm infants with respiratory distress.

Methods

We enrolled 42 preterm infants with respiratory distress who underwent serial echocardiographic evaluation with simultaneous plasma BNP measurements until ductal closure. The correlations between BNP levels and the following 4 representative echocardiographic parameters were studied: diameter of the ductus arteriosus (DA), ratio of the left atrial diameter to the aortic diameter (LA/Ao), ratio of the PDA diameter to the infant's left pulmonary artery diameter (PDA/LPA), and the antegrade diastolic flow of LPA (DFLPA).

Results

BNP levels were significantly correlated to the magnitude of the ductal shunt, comprising the DA diameter, PDA/LPA ratio, LA/Ao ratio, and antegrade DFLPA for the overall study period. The earliest significant correlation, starting from postnatal day 2, was observed between the LA/Ao ratio and BNP levels. The PDA/LPA ratio and the antegrade DFLPA showed significant correlations with BNP levels postnatal day 3 onward, and with the DA diameter, postnatal day 5 onward.

Conclusion

BNP levels and echocardiographic parameters showed a positive correlation, but the significance of the correlations differed according to the postnatal age, especially during the first few days of life.

Recent Advances in the Treatment of Preterm Newborn Infants with Patent Ductus Arteriosus

A patent ductus arteriosus (PDA) is associated with several adverse clinical conditions. Several strategies for PDA treatment exist, although data regarding the benefits of PDA treatment on outcomes are sparse. Moreover, the optimal treatment strategy for preterm neonates with PDA remains subject to debate. It is still unknown whether and when PDA treatment should be initiated and which approach (conservative, pharmacologic, or surgical) is best for individual patients (tailored therapies). This article reviews the current strategies for PDA treatment with a special focus on recent developments such as oral ibuprofen, high-dose regimens, and the use of paracetamol (oral, intravenous).