Learning to live with patency of the ductus arteriosus in preterm infants

Impact of Nutritional Status on Total Brain Tissue Volumes in Preterm Infants

Preterm infants bypass the crucial in utero period of brain development and are at increased risk of malnutrition. We aimed to determine if their nutritional status is associated with brain tissue volumes at term equivalent age (TEA), applying recently published malnutrition guidelines for preterm infants. We performed a single center retrospective chart review of 198 infants < 30 weeks' gestation between 2018 and 2021. We primarily analyzed the relationship between the manually obtained neonatal MR-based brain tissue volumes with the maximum weight and length z-score. Significant positive linear associations between brain tissue volumes at TEA and weight and length z-scores were found (p < 0.05). Recommended nutrient intake for preterm infants is not routinely achieved despite efforts to optimize nutrition. Neonatal MR-based brain tissue volumes of preterm infants could serve as objective, quantitative and reproducible surrogate parameters of early brain development. Nutrition is a modifiable factor affecting neurodevelopment and these results could perhaps be used as reference data for future timely nutritional interventions to promote optimal brain volume.

Fluid restriction in management of patent ductus arteriosus in Italy: a nationwide survey

We aimed at establishing the state of the art in fluid restriction practice in our national setting and providing a foundation for future research efforts. A prospective cross-sectional survey was conducted among all 114 Italian Neonatal Units in order to address conservative management of patent ductus arteriosus (PDA) in preterm infants below 29 weeks' gestational age (GA), with specific regard to fluid restriction. Response rate was 80%. Conservative measures for PDA management are provided in the majority of NICUs and 80% of centers reduce fluid intake in neonates with PDA. No relationship can be found among pharmacologically or surgically treated patients per year and the approach to fluid restriction. The minimum intake administered at regimen when fluid restriction is applied is associated to the ratio between the maximum number of neonates managed pharmacologically and number of admitted < 29 weeks' GA newborns.

CONCLUSION

Our survey shows an extreme variability among centers in terms of use of fluid restriction as a prophylactic tool but also in terms of its use (both opportunity and modality) when a hemodynamically significant PDA is diagnosed. This variability, that can be also found in randomized trials and observational studies, suggests that further evidence is needed to better understand its potential beneficial effects and its potential harms such as dehydration, hypotension, decreased end-organ perfusion, and reduced caloric intake.

WHAT IS KNOWN

• The lack of demonstrable improvement following the treatment of patent ductus arteriosus has recently paved the way to a more conservative approach. • Fluid restriction is the most commonly applied conservative treatment of PDA.

WHAT IS NEW

• Among Italian NICUs an extreme variability in terms of indications, timing and modalities of application of Fluid restriction can be found. • This variability reflects the lack of standardization of this practice and the contrasting evidence on its efficacy.

Conservative Management of Patent Ductus Arteriosus Is Feasible in the Peri-Viable Infants at 22-25 Gestational Weeks

The purpose of this study was to determine the natural course of hemodynamically significant (HS) patent ductus arteriosus (PDA) with conservative management and whether the presence or prolonged duration of HS PDA affected mortality/morbidities in infants at 22-25 weeks estimated gestational age (EGA). We retrospectively reviewed the medical records of 77 infants born at 22-25 weeks EGA, stratified into 22-23 weeks (n = 21) and 24-25 weeks EGA (n = 56). HS PDA was present in 77%, 76%, and 77%, and open ductus at discharge was 12%, 13%, and 12% in the total and at 22-23 and 24-25 weeks EGA infants, respectively. For backup rescue treatment, 7% and 5% of the infants received oral ibuprofen and device closure, respectively. A mortality rate of 9% was found in the HS PDA (+) infants, significantly lower than the 28% in HS PDA (-) infants. There are no significant differences in morbidities. In multivariate analyses, the presence and/or prolonged duration of HS PDA was not associated with increased mortality or morbidity. Spontaneous closure of HS PDA was achieved through conservative management in the peri-viable infants at 22-25 weeks EGA.

Patent Ductus Arteriosus: A Contemporary Perspective for the Pediatric and Adult Cardiac Care Provider

The burden of patent ductus arteriosus (PDA) continues to be significant. In view of marked differences in preterm infants versus more mature, term counterparts (viewed on a continuum with adolescent and adult patients), mechanisms regulating ductal patency, genetic contributions, clinical consequences, and diagnostic and treatment thresholds are discussed separately, when appropriate. Among both preterm infants and older children and adults, a range of hemodynamic profiles highlighting the markedly variable consequences of the PDA are provided. In most contemporary settings, transcatheter closure is preferable over surgical ligation, but data on longer-term outcomes, particularly among preterm infants, are lacking. The present review provides recommendations to identify gaps in PDA diagnosis, management, and treatment on which subsequent research can be developed. Ultimately, the combination of refined diagnostic thresholds and expanded treatment options provides the best opportunities to address the burden of PDA. Although fundamental gaps remain unanswered, the present review provides pediatric and adult cardiac care providers with a contemporary framework in PDA care to support the practice of evidence-based medicine.

Natural evolution of the patent ductus arteriosus in the extremely premature newborn and respiratory outcomes

OBJECTIVE

Evaluate spontaneous closure of the patent ductus arteriosus (PDA) in extremely preterm infants and their respiratory outcomes, especially at <26 weeks gestational age (GA).

STUDY DESIGN

Retrospective study in <29 weeks, admitted within 24 h after birth (Feb 2015 and Dec 2019). Infants without any intervention to promote ductal closure, ≥1 echocardiography, and alive at discharge were included.

RESULTS

Two hundred and fourteen infants (average GA 26.3 ± 1.5 weeks) were included; 84 (39%) <26 weeks. PDA closed spontaneously in 194 (91%); 76/84 (90%) for infants <26 weeks. PDA closure was ascertained on an echocardiography performed at a median age of 36.4 [34.4-40.1] weeks. Rate of moderate-to-severe bronchopulmonary dysplasia decreased throughout the study period (OR for year of birth: 0.70 [95% CI: 0.57-0.87], p = 0.001).

CONCLUSION

Majority of extremely preterm infants, including <26 weeks, had spontaneous closure of the ductus before term corrected age. There was a concomitant improvement of respiratory outcomes.

Covariation of changing patent ductus arteriosus management and preterm infant outcomes in Pediatrix neonatal intensive care units

OBJECTIVE

To test the hypothesis that NICU-specific preterm infant outcomes co-vary with changes in local patent ductus arteriosus (PDA) management.

STUDY DESIGN

This retrospective multicenter study examined NICU-specific aggregated data for infants born 400-1499 g (VLBW) in the Pediatrix Clinical Data Warehouse. For each NICU and each year 2006-2016 we calculated proportion of infants receiving cyclooxygenase inhibitor (COXI) and/or PDA ligation and determined NICU-specific changes in these therapies between consecutive years. We examined relationships between NICU-specific changes in COXI/ligation and concurrent changes in local adjusted in-hospital outcomes.

RESULTS

In 5678 observations of change at 259 NICUs summarizing 78,105 infants, between-year decreases in NICU-specific proportion treated with COXI/ligation were associated with concurrent increases in local mortality and decreases in BPD among infants 400-749 g, and with decreased pulmonary hemorrhage in larger infants.

CONCLUSIONS

NICU-specific adjusted mortality, BPD, and pulmonary hemorrhage rates co-vary with changes in local COXI/ligation rates in some VLBW infant subgroups.

Outcomes of Extremely Premature Infants Comparing Patent Ductus Arteriosus Management Approaches

OBJECTIVE

To evaluate the change in the proportion of deaths/bronchopulmonary dysplasia (BPD) among premature infants (born <26 and 26-29 weeks of gestational age) following a policy change to a strict nonintervention approach, compared with standard treatment.

STUDY DESIGN

We examined 1249 infants (341 born <26 weeks of gestational age) at 2 comparable sites. Site 1 (control) continued medical treatment/ligation, and site 2 (exposed) changed to a nonintervention policy in late 2013. Using the difference-in-differences approach, which accounts for time-invariant differences between sites and secular trends, we assessed changes in death or BPD separately among infants born 26-29 weeks and <26 weeks of gestational age in 2 epochs (epoch 1: 2011-2013; epoch 2: 2014-2017).

RESULTS

Baseline characteristics were similar across sites and epochs. Medical treatment/ligation use remained stable at site 1 but declined progressively to 0% at site 2, indicating adherence to policy. We saw no difference in death/BPD among infants born at 26-29 weeks of gestational age (12%, 95% CI -1% to 24%). However, incidence of death/BPD increased by 31% among infants born <26 weeks of gestational age (95% CI 10%-51%) in site 2, whereas there was no change in outcomes in site 1. The Score for Neonatal Acute Physiology-Version II, used as a control outcome, did not change in either site, suggesting that our findings were not due to changes in patients' severity.

CONCLUSIONS

Adherence to a strict conservative policy did not impact death or BPD among 26 weeks but was associated with a significant rise in infants born <26 weeks.

Predictive Model of Early Spontaneous Ductus Arteriosus Closure Based on Neonatologist Performed Echocardiography in Preterm Infants

Background: Patent ductus arteriosus (PDA) treatment remains controversial. Modeling on the predictive capacity of early spontaneous PDA closure would help in decision-making. Aim: To design a predictive model of early spontaneous PDA closure. Methods: As part of a trial to assess efficacy and safety of two ibuprofen treatment schemes for PDA, infants below 29 weeks' gestation were scanned between 18 and 72 h of birth, and serially if indicated. PDA treatment was decided based on echocardiography signs of lung overflow or systemic hypoperfusion and clinical criteria. A PDA score that included the echocardiographic parameters significantly associated with treatment prescription was retrospectively applied. Perinatal variables and screening score were included in a backwards elimination model to predict early spontaneous closure. Results: Among 87 eligible infants (27 weeks' gestation; age at screening 45 h), 21 received ibuprofen at 69 h of life [screening score = 7 (IQR = 5-8.5); score at treatment = 9 (IQR = 8-9)], while 42 infants had conservative management, [screening score = 1 (IQR = 0-4)]. Twenty four infants were excluded (ibuprofen contraindication, declined consent or incomplete echocardiography). Screening score showed an AUC = 0.93 to predict early spontaneous PDA closure, [cut-off value = 4.5 (sensitivity = 0.90, specificity = 0.86)]. The predictive model for early spontaneous PDA closure followed the equation: Log (p/1-p) = -28.41 + 1.23^* gestational age -0.87^* PDA screening score. Conclusions: A predictive model of early spontaneous PDA closure that includes gestational age and the screening PDA score is proposed to help clinicians in the decision- making for PDA treatment. In addition, this model could be used in future intervention trials aimed to prevent PDA related morbidities to improve the eligibility criteria.

Clinical validity of systemic arterial steal among extremely preterm infants with persistent patent ductus arteriosus

OBJECTIVE

Investigate relevance of diastolic flow abnormalities in celiac trunk (aCT) and middle cerebral artery (aMCA) among preterms with persistent hemodynamically significant patent ductus arteriosus (phsPDA, diameter ≥ 1.5 mm, and age ≥ 7 days).

STUDY DESIGN

Five hundred fifteen echocardiograms from 156 neonates born <28 weeks gestation age (GA) were analyzed retrospectively. Infants with aCT or aMCA at any time were compared with the rest. Separate comparisons were performed for aCT and aMCA. Primary outcome was composite of death, chronic lung disease (CLD), or necrotizing enterocolitis ≥ stage 2. Logistic regression was used to adjust for confounders.

RESULT

Mean (SD) weight and GA were 820(214) g and 25.2(1.3) weeks. aMCA, but not aCT, was associated with primary outcome [adjusted odds ratio 2.17, 95% CI: 1.01-4.67] and CLD [2.20 (0.99-4.87)].

CONCLUSION

aMCA may be a valid marker for defining the clinical significance of phsPDA in preterm neonates. aCeT may be of limited value in selecting patients for treatment.

Effect of Nonintervention vs Oral Ibuprofen in Patent Ductus Arteriosus in Preterm Infants: A Randomized Clinical Trial

IMPORTANCE

Persistent patent ductus arteriosus (PDA) in preterm infants is associated with increased mortality and respiratory morbidities, including bronchopulmonary dysplasia (BPD). Despite recent increasing use of noninterventional approaches, no study to our knowledge has yet directly compared the nonintervention vs pharmacologic treatment for mediating PDA closure for decreasing mortality and preventing BPD.

OBJECTIVE

To determine the noninferiority of nonintervention vs oral ibuprofen treatment for PDA in decreasing BPD incidence or death in very preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, placebo-controlled, noninferiority clinical trial was conducted on preterm infants (gestational age [GA] 23-30 weeks) with hemodynamically significant PDA (ductal size >1.5 mm plus respiratory support) diagnosed between postnatal days 6 and 14. Participants included 383 infants screened between July 24, 2014, and March 15, 2019.

INTERVENTIONS

Infants were stratified by GA and randomly assigned (1:1) to receive either oral ibuprofen (initial dose of 10 mg/kg followed by a 5-mg/kg dose after 24 hours and a second 5-mg/kg dose after 48 hours) or placebo.

MAIN OUTCOMES AND MEASURES

The primary outcome was BPD or death; the secondary outcomes included major morbidities and ductal closure rates. Per-protocol analysis was used.

RESULTS

Among 383 infants screened for participation, 146 infants were randomly assigned, with 72 in the nonintervention and 70 in the ibuprofen treatment group in the final analyses. The PDA closure rate at 1 week after randomization was significantly higher with ibuprofen (11 [34%]) than nonintervention (2 [7%]) in infants at GA 27 to 30 weeks (P = .007); however, the findings were not significant at GA 23 to 26 weeks (ibuprofen, 3 [8%] vs nonintervention, 1 [2%], P = .34). In addition, the ductal closure rates before hospital discharge (ibuprofen, 62 [89%] vs nonintervention, 59 [82%], P = .27) and device closure (ibuprofen, 2 [3%] vs nonintervention, 4 [6%], P = .40) were not significantly different between the 2 groups. The nonintervention approach was noninferior to ibuprofen treatment in terms of BPD incidence or death (nonintervention, 44%; ibuprofen, 50%; 95% CI, -0.11 to 0.22; noninferiority margin -0.2; P = .51). One infant in the ibuprofen arm received oral ibuprofen backup rescue treatment owing to cardiopulmonary compromise refractory to conservative management, and another infant in the ibuprofen group received surgical ligation; none of the infants in the placebo group received backup treatment.

CONCLUSIONS AND RELEVANCE

Nonintervention showed noninferiority compared with ibuprofen treatment in closing of hemodynamically significant PDA and reduction of BPD or death. The noninferiority of nonintervention over ibuprofen might be attributable to the low efficacy of oral ibuprofen for closing PDA, especially in infants born at 23 to 26 weeks' gestation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02128191.

Amplatzer Piccolo Occluder clinical trial for percutaneous closure of the patent ductus arteriosus in patients ≥700 grams

Objectives

Characterize the safety and effectiveness of the Amplatzer Piccolo Occluder for patent ductus arteriosus (PDA) closure.

Background

The presence of a hemodynamically significant PDA has been associated with an increased risk of morbidity and mortality in children born premature.

Methods

This was a single arm, prospective, multicenter, non‐randomized study to evaluate the Amplatzer Piccolo Occluder to treat PDA in patients ≥700 g. From June 2017 to February 2019, 200 patients were enrolled at nine centers, with 100 patients weighing ≤2 kg. Primary effectiveness endpoint was the rate of PDA closure at 6‐month follow‐up. Primary safety endpoint was the rate of major complications through 6 months. Secondary endpoint was rate of significant pulmonary or aortic obstruction through 6 months' follow‐up.

Results

The implant success rate was 95.5% (191/200) overall and 99% in patients ≤2 kg (99/100). The primary effectiveness endpoint was achieved in 99.4% of implanted patients. Four patients experienced a primary safety endpoint event (2 transfusions, 1 hemolysis, and 1 aortic obstruction). There were no branch pulmonary artery obstructions. Five patients, all ≤2 kg, were noted to have worsening of tricuspid regurgitation (TR) after the procedure. None of the TR incidences manifested clinically. The Amplatzer Piccolo Occluder received FDA approval in January 2019 and became the first device approved for PDA closure in patients ≥700 g.

Conclusions

This study supports the safety and effectiveness of the Amplatzer Piccolo Occluder, particularly in patients between 700 g and 2 kg where there is currently a significant unmet need in the United States. ClinicalTrials.gov identifier: NCT03055858.

Echocardiographic Diagnosis and Hemodynamic Evaluation of Patent Ductus Arteriosus in Extremely Low Gestational Age Newborn (ELGAN) Infants

Persistent Patent ductus arteriosus (PDA) is a common finding in extremely low gestational age newborn infants and its prevalence is inversely proportional to the gestational age. The presence of a persistent PDA is associated with increased mortality and several significant morbidities including intraventricular hemorrhage, pulmonary hemorrhage, necrotizing enterocolitis, and chronic lung disease or bronchopulmonary dysplasia. However, treating PDA has not been demonstrated to have beneficial impact on the long term outcomes. Currently there is no consensus on whether to treat the PDA or not, and if treat, when to treat and how to treat. The echocardiography is the investigation of choice to diagnose PDA, estimating the magnitude of shunt volume and assessing its hemodynamic significance, and to exclude/diagnose any associated congenital heart defect before any intervention. Various echocardiographic parameters and staging/scoring systems have been described to help the clincians making the clinical decisions and some of theses scoring systems are quite complex to apply in a busy day to day clinical practice. This concised review paper is focused to help the clinicians in making a clinical decision based upon clincial and echocardiography parameters. Hence, only the parameters which are commonly used and helpful in making the clinical decisions in day to day clincial practice have been described in this paper.

Conservative Non-intervention Approach for Hemodynamically Significant Patent Ductus Arteriosus in Extremely Preterm Infants

While persistent patent ductus arteriosus (PDA) in preterm infants has been known to be associated with increased mortality and morbidities including bronchopulmonary dysplasia, and necrotizing enterocolitis, there is minimal evidence supporting their causal relationships, and most traditional medical and/or surgical treatments have failed to show improvements in these outcomes. As such, the pendulum has swung toward the conservative non-intervention approach for the management of persistent PDA during the last decade; however, the benefits and risks of this approach are unclear. In this mini review, we focused on whom, when, and how to apply the conservative non-intervention approach for persistent PDA, especially in extremely preterm infants.

Natural evolution of ductus arteriosus with noninterventional conservative management in extremely preterm infants born at 23-28 weeks of gestation

This study aimed to determine the natural course of patent ductus arteriosus (PDA) with noninterventional conservative management and whether the presence and/or prolonged duration of hemodynamically significant (HS) PDA increased the risk of mortality and morbidities in extremely preterm (EPT) infants. We retrospectively reviewed the medical records of EPT infants born at 23-28 weeks of gestation (n = 195) from January 2011 to June 2014, when PDA was managed with noninterventional conservative treatment. We stratified infants into three subgroups of 23-24, 25-26, and 27-28 weeks and analyzed the prevalence and natural evolution of HS PDA, defined as ventilator dependency and PDA size ≥2 mm. Multivariate regression analyses determined if the presence and/or prolonged duration of HS PDA increased the risk for mortality and/or morbidities. The overall incidence of HS PDA was 57% (111/195) at the end of the first postnatal week. In subgroup analyses, infants with 23-24 weeks of gestation had the highest incidence (93%, 50/54), with 64% (47/74) for 25-26 weeks and 21% (14/67) for 27-28 weeks. Six (5%) of 111 infants with HS PDA were discharged without ductus closure, 4 had spontaneous PDA closure on follow up, and device closure was performed for 2 infants. In the multivariate analyses, the presence or prolonged duration (per week) of HS PDA was not associated with the risk of mortality and/or morbidities. Spontaneous closure of HS PDA was mostly achieved, even in EPT infants, with a noninterventional conservative approach. In conclusion, our data showed the incidence and natural course of HS PDA in EPT infants and suggested that the presence or prolonged duration of HS PDA might not increase the rate of mortality or morbidities.

Pharmacotherapy for patent ductus arteriosus closure

Even though up to 60% of premature infants less than 28 weeks gestation develop persistent patent ductus arteriosus (PDA), there remains controversy regarding if, when, and how to close the PDA. Failure to close the PDA has been associated with significant morbidity but no cause-and-effect has been proven for short-term or long-term outcomes in modern times. Surgical closure has the advantage of eliminating the PDA, but short-term complications and long-term adverse outcomes are worrisome. Intravenous indomethacin has been the "gold standard" for pharmacologic treatment over the past 40 years with high closure rates and decreased incidence of severe intraventricular hemorrhage (IVH) and pulmonary hemorrhage with early treatment but without improvement in long-term outcomes and with risk of renal toxicity. Intravenous ibuprofen has less vasoconstrictive toxicity than indomethacin with comparable closure rates but without improvement in IVH and with hyperbilirubinemia risks. Earlier this decade, acetaminophen (paracetamol) was discovered to effectively close the PDA with good short-term safety profile. Although promising, acetaminophen treatment requires further studies regarding long-term safety as well as ideal dosing and route of administration.

Covariation of Neonatal Intensive Care Unit-Level Patent Ductus Arteriosus Management and In-Neonatal Intensive Care Unit Outcomes Following Preterm Birth

OBJECTIVE

To test the hypothesis that neonatal intensive care unit (NICU)-specific changes in patent ductus arteriosus (PDA) management are associated with changes in local outcomes in preterm infants.

STUDY DESIGN

This retrospective repeated-measures study of aggregated data included infants born 400-1499 g admitted within 2 days of delivery to NICUs participating in the California Perinatal Quality Care Collaborative. The period 2008-2015 was divided into four 2-year epochs. For each epoch and NICU, we calculated proportions of infants receiving cyclooxygenase inhibitor (COXI) or PDA ligation and determined NICU-specific changes in these therapies between consecutive epochs. Generalized estimating equations were used to examine adjusted relationships between NICU-specific changes in PDA management and contemporaneous changes in local outcomes.

RESULTS

We included 642 observations of interepoch change at 119 hospitals summarizing 32 094 infants. NICU-specific changes in COXI use and ligation showed significant dose-response associations with contemporaneous changes in adjusted local outcomes. Each percentage point decrease in NICU-specific proportion treated with either COXI or ligation was associated with a 0.21 percentage point contemporaneous increase in adjusted local in-hospital mortality (95% CI 0.06, 0.33; P = .005) among infants born 400-749 g. In contrast, decreasing NICU-specific ligation rate among infants 1000-1499 g was associated with decreasing adjusted local bronchopulmonary dysplasia (P = .009) and death or bronchopulmonary dysplasia (P = .01).

CONCLUSIONS

NICU-specific outcomes of preterm birth co-vary with local PDA management. Treatment for PDA closure may benefit some infants born 400-749 g. Decreasing NICU-specific rates of COXI use or ligation were not associated with increases in local adjusted rates of examined adverse outcomes in larger preterm infants.

Early treatment versus expectative management of patent ductus arteriosus in preterm infants: a multicentre, randomised, non-inferiority trial in Europe (BeNeDuctus trial)

BACKGROUND

Much controversy exists about the optimal management of a patent ductus arteriosus (PDA) in preterm infants, especially in those born at a gestational age (GA) less than 28 weeks. No causal relationship has been proven between a (haemodynamically significant) PDA and neonatal complications related to pulmonary hyperperfusion and/or systemic hypoperfusion. Although studies show conflicting results, a common understanding is that medical or surgical treatment of a PDA does not seem to reduce the risk of major neonatal morbidities and mortality. As the PDA might have closed spontaneously, treated children are potentially exposed to iatrogenic adverse effects. A conservative approach is gaining interest worldwide, although convincing evidence to support its use is lacking.

METHODS

This multicentre, randomised, non-inferiority trial is conducted in neonatal intensive care units. The study population consists of preterm infants (GA < 28 weeks) with an echocardiographic-confirmed PDA with a transductal diameter > 1.5 mm. Early treatment (between 24 and 72 h postnatal age) with the cyclooxygenase inhibitor (COXi) ibuprofen (IBU) is compared with an expectative management (no intervention intended to close a PDA). The primary outcome is the composite of mortality, and/or necrotising enterocolitis (NEC) Bell stage ≥ IIa, and/or bronchopulmonary dysplasia (BPD) defined as the need for supplemental oxygen, all at a postmenstrual age (PMA) of 36 weeks. Secondary outcome parameters are short term sequelae of cardiovascular failure, comorbidity and adverse events assessed during hospitalization and long-term neurodevelopmental outcome assessed at a corrected age of 2 years. Consequences regarding health economics are evaluated by cost effectiveness analysis and budget impact analysis.

DISCUSSION

As a conservative approach is gaining interest, we investigate whether in preterm infants, born at a GA less than 28 weeks, with a PDA an expectative management is non-inferior to early treatment with IBU regarding to the composite outcome of mortality and/or NEC and/or BPD at a PMA of 36 weeks.

TRIAL REGISTRATION

This trial is registered with the Dutch Trial Register NTR5479 (registered on 19 October 2015), the registry sponsored by the United States National Library of Medicine Clinicaltrials.gov NCT02884219 (registered May 2016) and the European Clinical Trials Database EudraCT 2017-001376-28 .

Patent ductus arteriosus: The physiology of transition

The transition from intrauterine to extrauterine life represents a critical phase of physiological adaptation which impacts many organ systems, most notably the heart and the lungs. The majority of term neonates complete this transition without complications; however, dysregulation of normal postnatal adaptation may lead to acute cardiopulmonary instability, necessitating advanced intensive care support. Although not as well appreciated as changes in vascular resistances, the shunt across the DA plays a crucial physiologic role in the adaptive processes related to normal transitional circulation. Further, we describe key differences in the behavior of the ductal shunt during transition in preterm neonates and we postulate mechanisms through which the DA may modulate major hemodynamic complications during this vulnerable period. Finally, we describe the conditions in which preservation of ductal patency is a desired clinical goal and we discuss clinical factors that may determine adequate balance between pulmonary and systemic circulation.

Non-pharmacological management of a hemodynamically significant patent ductus arteriosus

The association between the patent ductus arteriosus (PDA) and neonatal morbidity, mortality and poor neurodevelopmental outcome in later childhood has been the focus of intense debate for decades. The lack of evidence supporting therapeutic strategies aimed at achieving PDA closure has led to the widespread adoption of conservative management aimed at mitigating the impact of shunt volume without achieving ductal closure. In this article, we review this management approach, describe the supportive evidence and potential complications associated with this strategy.

Early NT-proBNP levels as a screening tool for the detection of hemodynamically significant patent ductus arteriosus during the first week of life in very low birth weight infants

OBJECTIVE

To assess whether early NT-ProBNP can identify the need for echocardiographic assessment of hemodynamically significant patent ductus arteriosus (HsPDA) in preterm infants.

STUDY DESIGN

Prospective observational study of infants with a gestational age ≤32 weeks. Echocardiographic assessment and NT-proBNP measurement were performed at 48-96 h. ROC curves were generated to assess optimal cutoffs to detect HsPDA and predict the need for treatment.

RESULTS

Eighty-five patients were included. HsPDA was present in 28 infants (37.6%), and 22 (25.8%) received treatment. The optimal NT-proBNP cutoff for the detection of HsPDA was 5099 pg/mL (sensitivity 94%, specificity 82%, area under the curve 0.941, P < 0.001). Only 1 child with NT-proBNP levels <5099 pg/mL was ultimately treated for PDA. NT-proBNP screening could have avoided 45 of 85 routine echocardiograms (53%).

CONCLUSION

NT-proBNP screening at 48-96 h of life may identify preterm infants at low risk for HsPDA, improving PDA management.

Application of NPE in the assessment of a patent ductus arteriosus

In many preterm infants, the ductus arteriosus remains patent beyond the first few days of life. This prolonged patency is associated with numerous adverse outcomes, but the extent to which these adverse outcomes are attributable to the hemodynamic consequences of ductal patency, if at all, has not been established. Different treatment strategies have failed to improve short-term outcomes, with a paucity of data on the correct diagnostic and pathophysiological assessment of the patent ductus arteriosus (PDA) in association with long-term outcomes. Echocardiography is the selected method of choice for detecting a PDA, assessing the impact on the preterm circulation and monitoring treatment response. PDA in a preterm infant can result in pulmonary overcirculation and systemic hypoperfusion, Therefore, echocardiographic assessment should include evaluation of PDA characteristics, indices of pulmonary overcirculation with left heart loading conditions, and indices of systemic hypoperfusion. In this review, we provide an evidence-based overview of the current and emerging ultrasound measurements available to identify and monitor a PDA in the preterm infant. We offer indications and limitations for using Neonatologist Performed Echocardiography to optimize the management of a neonate with a PDA.

Trends and variation in management and outcomes of very low-birth-weight infants with patent ductus arteriosus

BACKGROUND

We examined recent trends and interhospital variation in use of indomethacin, ibuprofen, and surgical ligation for patent ductus arteriosus (PDA) in very-low-birth-weight (VLBW) infants.

METHODS

Included in this retrospective study of the Pediatric Hospital Information System database were 13,853 VLBW infants from 19 US children's hospitals, admitted at age < 3 d between 1 January 2005 and 31 December 2014. PDA management and in-hospital outcomes were examined for trends and variation.

RESULTS

PDA was diagnosed in 5,719 (42%) VLBW infants. Cyclooxygenase inhibitors and/or ligation were used in 74% of infants with PDA overall, however studied hospitals varied greatly in PDA management. Odds of any cyclooxygenase inhibitor or surgical treatment for PDA decreased 11% per year during the study period. This was temporally associated with improved survival but also with increasing bronchopulmonary dysplasia, periventricular leukomalacia, retinopathy of prematurity, and acute renal failure in unadjusted analyses. There was no detectable correlation between hospital-specific changes in PDA management and hospital-specific changes in outcomes of preterm birth during the study period.

CONCLUSION

Use of cyclooxygenase inhibitors and ligation for PDA in VLBW infants decreased over a 10-y period at the studied hospitals. Further evidence is needed to assess the impact of this change in PDA management.

Pharmacological Closure of Patent Ductus Arteriosus: Selecting the Agent and Route of Administration

Opinions are divided regarding the management of a persistently patent ductus arteriosus (PDA). Some of the adverse effects associated with a large hemodynamically significant duct, including prolonged ventilation, pulmonary hemorrhage, bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), and mortality, indicate that active management of infants with large ductal shunts may sometimes be necessary. Indomethacin and ibuprofen are the two US FDA-approved cyclooxygenase (COX) inhibitors used for the closure of a ductus in preterm babies. Both these drugs are effective in 70-80% of extremely low birthweight infants. Treatment with COX inhibitors may be associated with renal impairment, gastrointestinal hemorrhage, NEC, and spontaneous intestinal perforation when given concurrently with steroids, as well as changes in cerebrovascular auto-regulation. Ibuprofen appears to be a better choice for PDA closure, with a better side effect profile and efficacy that equals that of indomethacin. However, long-term outcome studies of ibuprofen are lacking, and prophylactic ibuprofen is ineffective in decreasing severe IVH. The choice of one drug over the other also depends on local availability of both drugs and the intravenous or enteral preparation. The oral preparation of ibuprofen appears as effective as the intravenous preparation. The use of paracetamol to close a hemodynamically significant PDA has increased in recent years. Paracetamol also decreases prostacyclin synthesis; however, unlike COX inhibitors, it does not have a peripheral vaso-constrictive effect and can be given to infants with contraindications to non-steroidal anti-inflammatory drugs. It appears to have similar efficacy based on limited data available from randomized trials. Until more data are available on efficacy, safety, and long-term outcomes, it cannot be recommended as the first choice.

Patent Ductus Arteriosus and Brain Volume

BACKGROUND AND OBJECTIVES

A hemodynamically significant patent ductus arteriosus (PDA) can compromise perfusion and oxygenation of the preterm brain. Reports suggest that PDA is associated with increased mortality and morbidity. We hypothesize that long-standing low cerebral oxygenation due to PDA might affect brain volume at term equivalent age.

METHODS

Observational study in 140 infants investigating the relationship between near-infrared spectroscopy-monitored cerebral oxygen saturation (rSco2) and MRI-assessed regional brain volume and maturation of the posterior limb of the internal capsule at term-equivalent age in 3 groups: those whose PDA closed with indomethacin, those who needed additional surgical closure, and matched controls.

RESULTS

The surgery group had the lowest rSco2 values before closure (n = 35), 48% ± 9.7% (mean ± SD) as compared with the indomethacin (n = 35), 59% ± 10.4 (P < .001), and control groups (n = 70), 66% ± 6.9 (P < .001); the highest postnatal age before effective treatment; and the lowest volumes of most brain regions at term-equivalent age. Multiple linear regression analysis showed a significant effect of preductal closure rSco2 on cerebellar volume in this group. No differences were found in maturation of the posterior limb of the internal capsule.

CONCLUSIONS

Long-standing suboptimal cerebral oxygenation due to a PDA may negatively influence brain growth, affecting neurodevelopmental outcome.

Patent Ductus Arteriosus in Preterm Infants

Despite a large body of basic science and clinical research and clinical experience with thousands of infants over nearly 6 decades,(1) there is still uncertainty and controversy about the significance, evaluation, and management of patent ductus arteriosus in preterm infants, resulting in substantial heterogeneity in clinical practice. The purpose of this clinical report is to summarize the evidence available to guide evaluation and treatment of preterm infants with prolonged ductal patency in the first few weeks after birth.

Comparative effectiveness and safety of indomethacin versus ibuprofen for the treatment of patent ductus arteriosus

BACKGROUND

Patent ductus arteriosus (PDA) is common in extremely premature infants and associated with increased morbidity and mortality. Medical management of PDA uses either indomethacin or ibuprofen. Despite numerous studies, uncertainty exists as to which drug is safer or more effective; we sought to fill this knowledge gap.

METHODS

We identified infants <28weeks gestational age discharged from neonatal intensive care units included in the Pediatrix Medical Group Clinical Data Warehouse between 2006 and 2012 who were treated with indomethacin or ibuprofen between postnatal days 2 and 14. Infants treated with both drugs or infants with a congenital malformation were excluded. We used multivariable logistic regression to determine the association of indomethacin versus ibuprofen on clinical outcomes.

RESULTS

Of 6349 patients who met study criteria, 1177 (19%) received ibuprofen and 5172 (81%) received indomethacin. The median gestational age was 25weeks (interquartile range 24-26), and 2894 (46%) infants were <750g at birth. On unadjusted analysis, infants who received ibuprofen had significantly higher incidences of death prior to discharge, surgical ligation of the PDA prior to discharge, death or spontaneous intestinal perforation within 7days of therapy, death or surgical ligation of the PDA prior to discharge, and an elevated creatinine within 7days of treatment. However, on multivariable analysis, no significant differences in outcomes were observed (odds ratio for death/PDA ligation for ibuprofen vs. indomethacin=1.12 [95% CI 0.91-1.39]).

CONCLUSIONS

We observed similar effectiveness and safety profiles for indomethacin and ibuprofen in the medical management of PDA in premature infants.

Potential Unintended Consequences of a Conservative Management Strategy for Patent Ductus Arteriosus

BACKGROUND

A recent review supports a strategy of deferring treatment of patent ductus arteriosus (PDA) in the preterm neonate until at least the second week after birth. In light of previous suggestion that later initiation of treatment may be less efficacious for closing PDAs it is reasonable to question if delayed treatment may be less effective.

DESIGN

We conducted a single center retrospective review of a neonatal intensive care unit database of infants ≤37 weeks gestation with the diagnosis of PDA and treated with indomethacin from 1999 to 2007. We determined gestational age (GA), timing of indomethacin initiation, and status of the PDA at hospital discharge. Treatment failure was defined as neonates requiring further intervention to close their PDA or those who died without echo-proven PDA closure.

RESULTS

Of the 341 infants meeting the study criteria, 77 (23%) had defined treatment failure. The failure group had a younger median GA of 25 weeks (interquartile range [IQR], 24-26) vs. 28 weeks (IQR, 26-30) for the successful group (P < .0001). The failure group had a median treatment initiation on day of life (DOL) 4 (IQR, 1-8) compared with DOL 3 (IQR, 1-6) for those in the successful group (P = .15). Taken as a whole, infants treated after DOL 5 were significantly more likely to have treatment failure (30.1% vs. 19.3% for those treated DOL 1-5, P = .03).

CONCLUSIONS

Our study confirms that younger GA at birth is correlated with increased likelihood of failed PDA closure. We also show a trend indicating that later initiation of treatment may decrease the chances of successfully closing a PDA. Future examination of PDA management should consider the potential unintended consequences that may accompany a delayed treatment strategy.

Serial N-terminal pro-brain natriuretic peptide measurement as a predictor of significant patent ductus arteriosus in preterm infants beyond the first week of life

The aim of the study was to assess the role of plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration as a predictor of patent ductus arteriosus (PDA) in very low birth weight infants beyond the first week of life. This was a prospective observational study; newborns with a birth weight < 1500 g were eligible for enrolment. Enrolled infants were screened by echocardiography on day seven of life for the presence of a PDA. This was paired with a blood sample for NT-proBNP level. Echocardiography and NT-proBNP levels were repeated at weekly intervals. The primary outcome was correlation between PDA and NT-proBNP level and between measurements of PDA significance and NT-proBNP. Sixty-nine neonates were enrolled following parental consent. The mean birth weight was 1119 ± 257 g and mean gestational age was 28.6 ± 2.6 weeks. Median NT-proBNP level on day seven was 11469 ng/l in infants with a PDA vs. 898 ng/l in infants without a PDA (p < 0.0001). There was a statistically significant correlation between PDA diameter and NT-proBNP level on day seven, day 14 and day 21.

CONCLUSION

NT-proBNP concentration is significantly increased in infants with a PDA and correlates well with PDA diameter in the first three weeks of life.

Short-term outcomes for preterm infants with surgical necrotizing enterocolitis

OBJECTIVE

To characterize the population and short-term outcomes in preterm infants with surgical necrotizing enterocolitis (NEC).

STUDY DESIGN

Preterm infants with surgical NEC were identified from 27 hospitals over 3 years using the Children's Hospitals Neonatal Database; infants with gastroschisis, volvulus, major congenital heart disease or surgical NEC that resolved prior to referral were excluded. Patient characteristics and pre-discharge morbidities were stratified by gestational age (<28 vs 28(0/7) to 36(6/7) weeks' gestation).

RESULT

Of the 753 eligible infants, 60% were born at <28 weeks' gestation. The median age at referral was 14 days; only 2 infants were inborn. Male gender (61%) was overrepresented, whereas antenatal steroid exposure was low (46%). Although only 11% had NEC totalis, hospital mortality (<28 weeks' gestation: 41%; 28(0/7) to 36(6/7) weeks' gestation: 32%, P=0.02), short bowel syndrome (SBS)/intestinal failure (IF) (20% vs 26%, P=0.06) and the composite of mortality or SBS/IF (50% vs 49%, P=0.7) were prevalent. Also, white matter injury (11.7% vs 6.6%, P=0.02) and grade 3 to 4 intraventricular hemorrhages (23% vs 2.7%, P<0.01) were commonly diagnosed. After referral, the median length of hospitalization was longer for survivors (106 days; interquartile range (IQR) 79, 152) relative to non-survivors (2 days; IQR 1,17; P<0.001). These survivors were prescribed parenteral nutrition infrequently after hospital discharge (<28 weeks': 5.2%; 28(0/7) to 36(6/7) weeks': 9.9%, P=0.048).

CONCLUSION

After referral for surgical NEC, the short-term outcomes are grave, particularly for infants born <28 weeks' gestation. Although analyses to predict outcomes are urgently needed, these data suggest that affected infants are at a high risk for lengthy hospitalizations and adverse medical and neuro-developmental abnormalities.

Patent ductus arteriosus ligation and adverse outcomes: causality or bias?

Observational studies have associated patent ductus arteriosus (PDA) ligation in preterm infants with increased chronic lung disease (CLD), retinopathy of prematurity, and neurodevelopmental impairment at long-term follow-up. Although the biological rationale for this association is incompletely understood, there is an emerging secular trend toward a permissive approach to the PDA. However, insufficient adjustment for postnatal, pre-ligation confounders, such as intraventricular hemorrhage and the duration and intensity of mechanical ventilation, suggests the presence of residual bias due to confounding by indication, and obliges caution in interpreting the ligation-morbidity relationship. A period of conservative management after failure of medical PDA closure may be considered to reduce the number of infants treated with surgery. Increased mortality and CLD in infants with persistent symptomatic PDA suggests that surgical ligation remains an important treatment modality for preterm infants.

Predictors of bronchopulmonary dysplasia or death in premature infants with a patent ductus arteriosus

BACKGROUND

Preterm infants with a patent ductus arteriosus (PDA) are at risk for death or development of bronchopulmonary dysplasia (BPD). However, PDA treatment remains controversial. We investigated if PDA treatment and other clinical or echocardiographic (ECHO) factors were associated with the development of death or BPD.

METHODS

We retrospectively studied clinical and ECHO characteristics of preterm infants with birth weight <1,500 g and ECHO diagnosis of a PDA. Logistic regression and classification and regression tree analyses were performed to assess variables associated with the combined outcome of death or BPD.

RESULTS

Of 187 preterm infants with a PDA, 75% were treated with indomethacin or surgical ligation and 25% were managed conservatively. Death or BPD occurred in 80 (43%) infants. The results of logistic regression analyses showed that lower gestational age (odds ratio (OR): 0.5), earlier year of birth during the study period (OR: 0.9), and larger ductal diameter (OR: 4.3) were associated with the decision to treat the PDA, whereas gestational age was the only variable associated with death or BPD (OR: 0.6; 95% confidence interval: 0.5-0.8).

CONCLUSION

Only lower gestational age and not PDA treatment or ECHO score was associated with the adverse outcome of death or BPD. Further investigation of PDA management strategies and effects on adverse outcomes of prematurity is needed.

The timing of surgical ligation for patent ductus arteriosus is associated with neonatal morbidity in extremely preterm infants born at 23-25 weeks of gestation

The purpose of this study was to evaluate prognostic factors associated with surgical ligation for patent ductus arteriosus (PDA) in extremely preterm infants born at the limits of viability. Ninety infants who were born at 23-25 weeks of gestation and who received surgical ligation were included and their cases were retrospectively reviewed. Infants were classified into two different groups: survivors with no major morbidity (N), and non-survivors or survivors with any major morbidity (M). Clinical characteristics were compared between the groups. Possible prognostic factors were derived from this comparison and further tested by logistic regression analysis. The mean gestational age and the mean birth weight of M were significantly lower than those of N. Notably, the mean postnatal age at time of ligation in N was significantly later than that of the other group (17 ± 12 vs 11 ± 8 days in N and M, respectively). An adjusted analysis showed that delayed ligation (>2 weeks) was uniquely associated with a significantly decreased risk for mortality or composite morbidity after surgical ligation (OR, 0.105; 95% CI, 0.012-0.928). In conclusion, delayed surgical ligation for PDA (>2 weeks) is associated with decreased mortality or morbidities in extremely preterm infants born at 23-25 weeks of gestation.

A randomised placebo-controlled trial of early treatment of the patent ductus arteriosus

OBJECTIVE

Failure of closure of the patent ductus arteriosus (PDA) may be associated with harm. Early cardiac ultrasound-targeted treatment of a large PDA may result in a reduction in adverse outcomes and need for later PDA closure with no increase in adverse effects.

STUDY DESIGN

Multicentre, double-blind, placebo-controlled randomised trial.

SETTING

Three neonatal intensive care units in Australia.

PATIENTS AND INTERVENTIONS

Eligible infants born <29 weeks were screened for a large PDA and received indomethacin or placebo before age 12 h.

MAIN OUTCOME

Death or abnormal cranial ultrasound.

RESULTS

The trial ceased enrolment early due to lack of availability of indomethacin. 164 eligible infants were screened before 12 h; of the 92 infants with a large PDA, 44 were randomised to indomethacin and 48 to placebo. There was no difference in the main outcome between groups. Infants receiving early indomethacin had significantly less early pulmonary haemorrhage (PH) (2% vs 21%), a trend towards less periventricular/intraventricular haemorrhage (PIVH) (4.5% vs 12.5%) and were less likely to receive later open-label treatment for a PDA (20% vs 40%). The 72 non-randomised infants with a small PDA were at low risk of pulmonary haemorrhage and had an 80% spontaneous PDA closure rate.

CONCLUSIONS

Early cardiac ultrasound-targeted treatment of a large PDA is feasible and safe, resulted in a reduction in early pulmonary haemorrhage and later medical treatment but had no effect on the primary outcome of death or abnormal cranial ultrasound.

REGISTERED TRIAL

Australian New Zealand Clinical Trials Registry (ACTRN12608000295347).

Neonatal Informatics: Transforming Neonatal Care Through Translational Bioinformatics

The future of neonatal informatics will be driven by the availability of increasingly vast amounts of clinical and genetic data. The field of translational bioinformatics is concerned with linking and learning from these data and applying new findings to clinical care to transform the data into proactive, predictive, preventive, and participatory health. As a result of advances in translational informatics, the care of neonates will become more data driven, evidence based, and personalized.

Patent ductus arteriosus: are current neonatal treatment options better or worse than no treatment at all?

Although a moderate-sized patent ductus arteriosus (PDA) needs to be closed by the time a child is 1-2 years old, there is great uncertainty about whether it needs to be closed during the neonatal period. Although 95% of neonatologists believe that a moderate-sized PDA should be closed if it persists in infants (born before 28 weeks) who still require mechanical ventilation, the number of neonatologists who treat a PDA when it occurs in infants who do not require mechanical ventilation varies widely. Both the high likelihood of spontaneous ductus closure and the absence of randomized controlled trials, specifically addressing the risks and benefits of neonatal ductus closure, add to the current uncertainty. New information suggests that early pharmacologic treatment has several important short-term benefits for the preterm newborn. By contrast, ductus ligation, while eliminating the detrimental effects of a PDA on lung development, may create its own set of morbidities that counteract many of the benefits derived from ductus closure.