Hemodynamic assessment of the patent ductus arteriosus: Beyond ultrasound

Ductus arteriosus diameters in fetuses with early- and late-onset fetal growth restriction

PURPOSE

Fetal growth restriction (FGR) is a common pregnancy complication that can be associated with several adverse perinatal outcomes. One of these negative outcomes is ductus arteriosus, especially in preterm babies. In this study, intrauterine heart function and ductus diameter were evaluated in babies with FGR.

METHODS

Thirty-seven fetuses with FGR were compared with 37 normal-weight fetuses at the same gestational week. In our study, ventricular diameters, aorta, pulmonary artery, ductus arteriosus (DA), aortic arch diameter, and flow traces were examined. In addition, the aorta and aortic isthmus diameters were proportioned to the ductus diameter, and the left ventricular myocardial performance index (MPI) [(ICT + IRT)/ET] was evaluated.

RESULTS

There was no difference in DA diameters between the patient and control groups. The intragroup comparison of the cases with early- and late-onset FGR revealed no statistically significant difference between DA diameters. However, the ratios of the aortic annulus diameter/ductus diameter (AOD/DAD) and aortic isthmus diameter/ductus diameter (AID/DAD) were significantly lower in early-onset FGR because the diameter of the DA was greater. In addition, the mod-MPI values were higher in the patient group.

CONCLUSIONS

In our study, although the ductal diameters did not change significantly in the patient group, the ductal diameter was greater in the early-onset intrauterine growth restriction (FGR) group compared with other cardiac measurements. The mod-MPI value, a cardiac function indicator, was higher in fetuses with FGR. These findings may be useful for evaluating postnatal cardiac functions in FGR.

Automated Identification of Patent Ductus Arteriosus Using a Computer Vision Model

OBJECTIVES

Patent ductus arteriosus (PDA) is a vascular defect common in preterm infants and often requires treatment to avoid associated long-term morbidities. Echocardiography is the primary tool used to diagnose and monitor PDA. We trained a deep learning model to identify PDA presence in relevant echocardiographic images.

METHODS

Echocardiography video clips (n = 2527) in preterm infants were reviewed by a pediatric cardiologist and those relevant to PDA diagnosis were selected and labeled (PDA present/absent/indeterminate). We trained a convolutional neural network to classify each echocardiography frame of a clip as belonging to clips with or without PDA. A novel attention mechanism that aggregated predictions for all frames in each clip to obtain a clip-level prediction by weighting relevant frames.

RESULTS

In early model iterations, we discovered training with color Doppler echocardiography clips produced the best performing classifier. For model training and validation, 1145 such clips from 66 patients (661 PDA+ clips, 484 PDA- clips) were used. Our best classifier for clip level performance obtained sensitivity of 0.80 (0.83-0.90), specificity of 0.77 (0.62-0.92) and AUC of 0.86 (0.83-0.90). Study level performance obtained sensitivity of 0.83 (0.72-0.94), specificity of 0.89 (0.79-1.0) and AUC of 0.93 (0.89-0.98).

CONCLUSIONS

Our novel deep learning model demonstrated strong performance in classifying echocardiography clips with and without PDA. Further model development and external validation are warranted. Ultimately, integration of such a classifier into auto detection software could streamline PDA imaging workflow. This work is the first step toward semi-automated, bedside detection of PDA in preterm infants.

Lung ultrasound score predicts patent ductus arteriosus ligation among neonates ≤25 weeks

BACKGROUND

This prospective study aimed to investigate whether lung ultrasound score (LUSs) can predict the patent ductus arteriosus (PDA) ligation.

METHODS

Preterm infants ≤25 weeks of gestational age (GA) were enrolled. A lung ultrasound was performed on the 14th day of life. Each lung zone was given a score between 0 and 4. A receiver-operating characteristic (ROC) curve was constructed to evaluate the ability of the LUSs for predicting ligation.

RESULTS

A total of 81 infants were eligible with a median GA and birth weight (BW) of 25 weeks (24.1-25.2) and 710 g (645-770), respectively. The median time from birth to ligation was 35 days (32-51). Those who underwent ligation had a longer time of mechanical ventilation (34 [26-39] vs. 19 [12-30], p < 0.001), shorter time of noninvasive respiratory support (39 [32-51] vs. 50 [41.5-57], p < 0.01), higher incidence of the bronchopulmonary dysplasia (BPD) (p < 0.01), and severe BPD (p < 0.001). The LUSs had an area under the ROC of 0.96 (95% confidence interval: 0.93-0.99) for the prediction of ligation. A LUSs cutoff of 36 has a sensitivity and specificity of 96% and 86% and positive and negative predictive values of 82% and 98%, respectively.

CONCLUSIONS

LUSs at an early stage of life can predict PDA ligation in extremely preterm infants. It would be helpful to reduce morbidity by reducing the duration and magnitude of respiratory support.

Evaluation of Cardiac Function Characteristics after Patent Ductus Arteriosus Closure in Children and Adults by Echocardiographic Data

This study was to investigate the value of echocardiographic data in assessing changes in cardiac function before and after transcatheter closure in children and adult patients with patent ductus arteriosus (PDA). In this study, 150 patients with isolated PDA treated by cardiac catheterization and transcatheter closure were selected as the study sample. Real-time color Doppler echocardiography was used both after and after operation. The results showed that the left ventricle returned to normal in 75 patients one day after operation, with an average age of 10.95 ± 3.27 years; the left ventricle did not return to normal in 10 patients 360 days after operation, with an average age of 64.31 ± 7.05 years. Left ventricular end diastolic volume index (LVEDVI) and left ventricular end systolic volume index (LVESVI) of patients decreased significantly one day after operation and remained at 51.95 ± 9.55 mL/m2 and 20.36 ± 8.11 mL/m-2, respectively. In summary, echocardiographic data have a high reference value in assessing cardiac function characteristics in children and adult patients with PDA and are worthy of further promotion.

Neurodevelopmental outcomes of singleton large for gestational age infants <29 weeks' gestation: a retrospective cohort study

OBJECTIVE

To compare neurodevelopmental outcomes of large and appropriate for gestational age (LGA, AGA) infants <29 weeks' gestation at 18-24 months of corrected age.

STUDY DESIGN

Retrospective cohort study using the Canadian Neonatal Network and Canadian Neonatal Follow-Up Network databases. Primary outcome was a composite of death or significant neurodevelopmental impairment (NDI), defined as severe cerebral palsy, Bayley III cognitive, language and motor scores of <70, need for hearing aids or cochlear implant and bilateral visual impairment. Univariate and multivariable logistic analyses were applied for outcomes.

RESULTS

The study cohort comprised 170 LGA and 1738 AGA infants. There was no difference in significant NDI or individual components of the Bayley III between LGA and AGA groups. LGA was associated with the increased risk of death by follow-up, 44/170 (25.9%) vs. 320/1738 (18.4%) (aOR: 1.60 95% CI: 1.00-2.54).

CONCLUSIONS

Risk of NDI was similar between LGA and AGA infants.

Association between intrauterine growth restriction and patent ductus arteriosus: Use of a dichorionic twin pregnancy model

OBJECTIVE

To evaluate the association between intrauterine growth restriction (IUGR) and the incidence of fetuses with patent ductus arteriosus (PDA) and Hemodynamically significant PDA (Hs-PDA) in dichorionic twins (DC) with selective IUGR.

MATERIALS AND METHODS

This is an observational cohort study and retrospective case assessment, involved twins born at Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan between 2013 and 2018. DC twins with selective IUGR (sIUGR) were defined as the presence of a birth weight discordance of >25% and a smaller twin with a birth weight below the tenth percentile. PDA was diagnosed using echocardiography between postnatal day 3 and 7. Hs-PDA was defined as PDA plus increased pulmonary circulation, poor systemic perfusion, cardiomegaly, pulmonary edema, or hypotension requiring pharmacotherapeutic intervention.

RESULT

A total of 1187 twins were delivered during the study period, and 53 DC twins with selective IUGR were included in this study. DC twins with PDA have higher rate of preterm birth, lower gestational age of delivery, and lower mean birth weight of both twins compared with DC twins without PDA. In a comparison of the sIUGR twin with the appropriate for gestational age co-twin, both the incidences of PDA (28.30% vs. 7.55%, respectively; P = 0.003) and Hs-PDA (24.53% vs. 5.66%, respectively; P = 0.002) were higher in sIUGR fetuses than in the appropriate for gestational age co-twins. Small gestational age of delivery was the only variable to predict PDA and Hs-PDA [p = 0.002, Odds ratio = 0.57 (0.39-0.82), p = 0.009, Odds ratio = 0.71 (0.55-0.92), respectively].

CONCLUSION

An analysis of dichorionic twins with sIUGR indicated that IUGR increased the risk of PDA and hemodynamically significant PDA.

Oral Versus Intravenous Medications for Treatment of Patent Ductus Arteriosus in Preterm Neonates: A Cost-Saving Initiative

OBJECTIVE

The purpose of the study was to quantify cost savings after promoting oral pharmacotherapy for the treatment of hemodynamically significant patent ductus arteriosus (hsPDA).

METHODS

This was a retrospective before-and-after time series quality improvement study. Oral ibuprofen and acetaminophen use criteria were developed and recommended, rather than the more costly intravenous equivalents. There were 24-month medication use reports generated for both the pre-criteria (Era-1) and the post-criteria (Era-2) implementation phases to identify neonates prescribed hsPDA medications in order to assess cost differences.

RESULTS

Era-1 had 190 treatment courses in 110 neonates for a total medication cost of $171,260.70. Era-2 had 210 courses in 109 patients for a total medication cost of $47,461.49, yielding savings of $123,799.21 ($61,899.61 annually) after criteria implementation. The reduction in intravenous ibuprofen use in Era-2 accounted for all the savings.

CONCLUSION

Preferentially prescribing lower-cost oral medications to treat hsPDA led to significant cost savings.

A Pilot Randomized Controlled Trial of Early Targeted Patent Ductus Arteriosus Treatment Using a Risk Based Severity Score (The PDA RCT)

OBJECTIVES

To evaluate the feasibility of recruiting preterm infants to a randomized controlled trial of patent ductus arteriosus (PDA) treatment based on a PDA severity score (PDAsc) and to characterize challenges in obtaining consent, compliance with the protocol, and PDA closure rates.

STUDY DESIGN

This single-center, randomized control pilot study of 60 infants <29 weeks of gestation with a high PDAsc (≥5.0) at 36-48 hours of age receiving either ibuprofen or placebo intravenously. The study protocol did not allow for additional PDA therapy within the first 2 weeks. We reported the rate of consent, open label treatment, and PDA closure rates. The primary outcome was chronic lung disease or death.

RESULTS

We approached 83 families for enrollment with 73 (88%) providing consent; 13 infants had a PDAsc of <5; of the remaining infants, 30 were assigned ibuprofen and 30 received placebo. Eight infants received open label treatment in the first 2 weeks (12%). The overall PDA closure rate after treatment was 57% in the intervention group and 17% in the control group (P < .01). There was no difference in the primary clinical outcome (OR, 0.8; 95% CI, 0.3-2.1).

CONCLUSIONS

Using a PDAsc for infant recruitment to a PDA treatment randomized controlled trial is feasible. There is a high rate of consent and relatively low rate of open-label PDA treatment. The overall PDA closure rate in the intervention arm was low placing the emphasis on devising more effective PDA closure strategies in future randomized controlled trials.

TRIAL REGISTRATION

ISRCTN (13281214) and European Union Drug Regulating Authorities Clinical Trials Database (2015-004526-33).

Patent Ductus Arteriosus Clinical Trials: Lessons Learned and Future Directions

The identification of an optimal management strategy for the patent ductus arteriosus (PDA) in the context of extreme prematurity remains elusive. Observational studies have reported a persistent association between PDA and neonatal adverse outcomes, but by and large, no clinical trial, to date, has demonstrated that treating a PDA results in a reduction of those morbidities. This discrepancy has led many to assume that the PDA is an innocent bystander in the physiological mechanisms responsible for such complications and a reluctance to actively pursue shunt elimination. It would be remiss to discount the volume of evidence available clearly documenting a strong association between longstanding PDA exposure and negative outcomes. There needs to be a radical change in the design, patient selection and possible outcome assessment in any further trials addressing the PDA. The purpose of this review is to explore the reasons that preclude existing clinical trials from definitively ascribing a causal relationship between PDA patency and adverse outcomes in the context of extreme prematurity, why previous studies have failed to demonstrate significant beneficial effects following PDA treatment and how future research may be conducted to allow us to draw concrete conclusions regarding the potential merits of ductal closure.

SIMPLE: A Novel Scoring System for Predicting Hemodynamically Significant Patent Ductus Arteriosus Without Echocardiographic Evaluation in Extremely Low Birth Weight Infants

Aim: To develop a novel clinical scoring system for predicting hemodynamically significant patent ductus arteriosus (hsPDA) in extremely low birth weight (ELBW) infants. Methods: A prospective observational study was conducted among ELBW infants born in the study center during a 6-month period. Fourteen items were selected on a literature review basis and weighed by severity on an arbitrary 1-4 scale, the sum of which represented the Scoring preterm Infants for PDA cLinically without Echocardiographic evaluation (SIMPLE) score. The SIMPLE scores were compared at several time points during the first 3 days of life between two groups of patients: those with an hsPDA at echocardiography and those without. Results: A total of 48 ELBW infants were enrolled, of which 30 infants developed hsPDA. The SIMPLE scores of the infants with hsPDA were significantly greater than those of the infants who did not develop hsPDA. Cut-off SIMPLE scores that were significantly associated with detection of symptomatic hsPDA at each evaluation time point were identified. Conclusions: SIMPLE is the first scoring system that depends on the risk factors and clinical findings of ELBW infants for early prediction of hsPDA. It is simple, objective and easy to perform, and it does not require any additional tests and/or echocardiographic evaluation. We suggest that SIMPLE can be used as a screening tool for determining the need for echocardiographic evaluation in ELBW infants in order to minimize the number of unnecessary pediatric cardiology consultations.

Patent ductus arteriosus and cerebral, cardiac, and gut hemodynamics in premature neonates

Patent ductus arteriosus is associated with multiple comorbidities in premature infants, however a causal link or strategy to decrease these morbidities has not been found. The association between the patent ductus arteriosus and morbidities has biologic plausibility as, like any cardiac mixing lesion, a significant systemic to pulmonic shunt may lead to pulmonary over-circulation and systemic hypoperfusion. Understanding the underlying pathophysiology of associated morbidities in the setting of a patent ductus arteriosus may aid in risk stratifying infants and offer a patient targeted approach to infants with a pathological ductal shunt. While the deleterious impact of increased pulmonary blood flow maybe easier to identify, the impact on end-organ perfusion is more challenging. In this review, we will discuss the pathophysiology of a hemodynamically significant patent ductus arteriosus in premature infants, impact on end-organ perfusion and associated morbidities, and novel modalities to assess shunt volume and effect on end-organ perfusion.

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.

Cardiovascular and cerebrovascular responses to cardio-respiratory events in preterm infants during the transitional period

KEY POINTS

Non-invasive simultaneous multiparametric monitoring allows the in vivo evaluation of cerebral and cardiovascular haemodynamic responses to different types of recurrent episodes of intermittent hypoxia and/or bradycardia, also defined as cardio-respiratory events (CRE), in preterm neonates during postnatal transition. By decreasing left cardiac output, bradycardia further contributes to cerebral hypoxia during CRE. The presence of a haemodynamically significant patent ductus arteriosus results in a deeper impairment of cerebral oxygen status in response to CRE, whereas the brain-sparing remodelling of the fetal circulation resulting from placental insufficiency is associated with more favourable haemodynamic responses to intermittent hypoxia. During transition, the haemodynamic impact of CRE is influenced not only by the event type, but also by specific clinical features; this highlights the importance of developing individualized approaches to reduce the hypoxic burden in this delicate phase.

ABSTRACT

The present observational prospective study aimed to investigate cerebral and cardiovascular haemodynamic responses to different types of cardio-respiratory events (CRE) in preterm infants during postnatal transition, as well as evaluate the impact of relevant clinical characteristics. Infants with gestational age (GA) <32 weeks and/or birth weight <1500 g were enrolled after birth. Cerebral oxygenation index (cTOI), fractional oxygen extraction (cFTOE), cardiac output (CO), cardiac contractility (iCON) and systemic vascular resistances (sVR) were simultaneously monitored over the first 72 h by near-infrared spectroscopy and electrical velocimetry. CRE were clustered into isolated bradycardia (IB), isolated desaturation (ID) and combined desaturation/bradycardia (DB). For each parameter, percentage changes from baseline (%Δ) were calculated. The impact of different CRE types and clinical variables on %Δ was evaluated with generalized estimating equations. In total, 1426 events were analysed. %ΔcTOI significantly differed among ID, IB and DB (P < 0.001), with the latter showing the greatest drop. %ΔcFTOE decreased significantly during DB (P < 0.001) and ID (P < 0.001) compared to IB. DB and IB were associated with more negative %ΔCO (P < 0.001) and more positive %ΔsVR (P < 0.001) compared to ID. A slight iCON reduction was observed during DB compared to ID (P = 0.043). Antenatal umbilical Doppler impairment, GA and the presence of a haemodynamically significant patent ductus arteriosus had a significant independent impact on %ΔcTOI, %ΔcFTOE and %ΔCO. During the transitional period, the haemodynamic responses to CRE are influenced by the event type and by specific neonatal characteristics, suggesting the importance of targeted individualized approaches for minimizing the risk of cerebral injury in the preterm population.

Use of combination therapy with acetaminophen and ibuprofen for closure of the patent ductus arteriosus in preterm neonates

Objective

To compare effectiveness and safety of combination therapy (acetaminophen and ibuprofen) to monotherapy (ibuprofen, indomethacin, or acetaminophen alone) in treatment of the patent ductus arteriosus (PDA) in premature neonates.

Methods

This was a retrospective cohort study of neonates admitted to a tertiary-level neonatal intensive care unit. Included neonates were born at <32 weeks gestation and received pharmacotherapy for PDA closure. Based on the primary therapy received, our cohort was divided into the following four groups: indomethacin alone, ibuprofen alone, acetaminophen alone, and ibuprofen and acetaminophen (in combination). Baseline characteristics, effectiveness, safety, neonatal mortality, and morbidities rates between these groups were compared.

Results

One hundred and forty neonates were analyzed; 17 received combination therapy, and 123 neonates received monotherapy: 22 (17.9%) ibuprofen, 29 (23.6%) acetaminophen, and 72 (58.5%) indomethacin. The PDA closure rates were 41.7% for indomethacin, 41.2% for combination therapy, 37.9% for acetaminophen, and 31.8% for ibuprofen (P=0.100). Rates of adverse effects were comparable between the groups.

Conclusion

The rate of ductal closure was not different between combination therapy and monotherapy. The study did not demonstrate any increased adverse effects in the combination group. Future well-designed prospective clinical trials are needed to guide clinical practice.

Near-Infrared Spectroscopy in Extremely Preterm Infants

With advances in neonatal care, survival of premature infants at the limits of viability has improved significantly. Despite these improvement in mortality, infants born at 22-24 weeks gestation are at a very high risk for short- and long-term morbidities associated with prematurity. Many of these diseases have been attributed to abnormalities of tissue oxygenation and perfusion. Near-infrared spectroscopy utilizes the unique absorption properties of oxyhemoglobin and deoxyhemoglobin to provide an assessment of regional tissue oxygen saturation, which can be used to calculate the fractional tissue oxygen extraction. This allows for a non-invasive way to monitor tissue oxygen consumption and enables targeted hemodynamic management. This mini-review provides a brief and complete overview of the background and physiology of near-infrared spectroscopy, practical use in extremely preterm infants, and potential applications in the neonatal intensive care unit. In this mini-review, we aim to summarize the three primary application sites for near-infrared spectroscopy, disease-specific indications, and available literature regarding use in extremely preterm infants.

Defining "Haemodynamic Significance" of the Patent Ductus Arteriosus: Do We Have All the Answers?

Optimum management of the patent ductus arteriosus (PDA) in preterm infants remains one of the most debated topics within the field of neonatology. Despite numerous observational studies and over 60 randomized control trials, consensus on PDA management remains elusive. In order to make meaningful progress on the controversial issue of PDA management, several key factors must be thoroughly addressed; namely (1) accurate identification of infants at greatest risk of long-term morbidities from PDA exposure, (2) acceptance that the PDA is not a dichotomous entity and an individualised approach to its management is required for each neonate, (3) international consensus on what constitutes a haemodynamically significant PDA and (4) the incorporation of multi-organ assessment when evaluating the impact a PDA may pose on overall neonatal physiology. This review assesses the evidence base available supporting various therapeutic strategies for PDA, the deficits in our current knowledge on the definition of haemodynamic significance and future directions to pursue in order to more successfully address this contentious subject.

Findings From Somatic and Cerebral Near-Infrared Spectroscopy and Echocardiographic Monitoring During Ductus Arteriosus Ligation: Description of Two Cases and Review of Literature

Background: Preterm infants with hemodynamically significant patent ductus arteriosus (HsPDA) are exposed to low cerebral tissue oxygen saturation (rScO₂) values. Additionally, infants requiring surgical ligation are at risk of further changes in cerebral oxygenation and postligation cardiac syndrome (PLCS). Previous studies have assessed the effect of PDA ligation on rScO₂ with variable results. Cases description: In this report we analyse near-infrared spectroscopy (NIRS) and echocardiographic findings of two patients who underwent ligation of PDA and presented low cardiac output. Literature on regional tissue oxygenation saturation (rSO2) before and after PDA ligation was briefly reviewed. Discussion: Cerebral oxygenation values before and after PDA ligation may be influenced by gestational age, vasopressor use, ductal shunt volume, time of exposure HsPDA, chronological age and the presence of cerebral autoregulation. PLCS complicates 28-45% of all PDA ligations and is associated with higher mortality. Cerebral and somatic NIRS monitoring in the postoperative period may enhance the identification of PLCS at early stages. Conclusion: Cerebral oxygenation in the perioperative period of PDA ligation may be influenced by numerous clinical factors. Early detection of PLCS using multisite NIRS after ligation could prevent further alterations in cerebral hemodynamics and improve outcomes. A decrease in somatic-cerebral difference and/or a significant drop in somatic NIRS values may precede clinical signs of hypoperfusion. NIRS values should be interpreted as trends along with echocardiographic findings to guide goal directed interventions.

PDA: Does it matter?

Management of persistent patent ductus arteriosus (PDA) continues to be a challenging issue. The attitude toward PDA has shifted in the opposite direction during the last 20 years, from advocating an aggressive and early closure toward a call for watchful observation. While persistent PDA may cause challenges in the medical management of preterm neonates secondary to volume overload, pulmonary edema or hemorrhage, hypotension, and impaired tissue perfusion, its contribution toward long-term neonatal morbidities including bronchopulmonary dysplasia (BPD), ROP, NEC, and NDI has not been substantiated. By advocating conservative management, it is clear now that the majority of the PDA cases show spontaneous closure and do not require treatment. However, there has not been agreement regarding what constitutes a hemodynamically significant PDA and when, if any, it should be targeted for treatment. With increasing concern regarding possible associated complications with PDA ligation, a new trend for transcatheter approach to PDA closure is expanding. In this review, we summarize current understanding of the pathophysiology, diagnosis, and management of PDA in preterm infants, and we make some recommendations regarding evidence-based approach.

[A review on the clinical application of high-sensitivity cardiac troponin T in neonatal diseases]

In recent years, high-sensitivity cardiac troponin T (hs-cTnT) has been recognized as an effective marker for myocardial injury in adults and can be used to diagnose acute myocardial injury and predict major adverse cardiovascular events. It is the gold standard for the diagnosis of acute myocardial infarction in adults. Neonates are a special group, and due to the changes of various physiological processes during the perinatal period, many laboratory markers used in adults may have a low clinical value in neonates. So far, for example, there is still no suitable cardiac serum biomarker that can reflect the true condition of neonatal myocardial injury. In recent years, new breakthroughs have been made in the application of hs-cTnT in the field of neonates. In order to fully understand the role of hs-cTnT in neonatal diseases, this article reviews the research advances in the biological and physiological features of hs-cTnT and its application in neonates.

[Splanchnic oximetry in small for gestational age neonates in relation to prenatal doppler study]

INTRODUCTION

Among small for gestational age neonates, foetal Doppler enables the identification of placental insufficency aetiology and the classification of severity in small for gestational age neonates. There are studies that associate the Doppler data with alterations in the intestinal flow of the newborn, but its relationship with intestinal oximetry has been little studied.

OBJECTIVE

To assess whether there is a relationship between prenatal Doppler data and abdominal oximetry in small for gestational age neonates MATERIAL AND METHODS: A prospective observational study carried out on neonates>32 weeks with a birth weight<P10. The severity of placental insufficiency was classified according to prenatal Doppler criteria. Splanchnic oximetry was monitored during the first three days of life and a comparative analysis of the oximetry data was performed according to the prenatal Doppler alteration severity.

RESULTS

A total of 53 patients were evaluated. Significant differences were observed in the mean regional oximetry (rSO₂) between patients with moderate or severe placental failure and those with normal or slightly altered prenatal Doppler: 42±10 vs. 71.3±10 (P<.001). These differences were maintained during the first 3 days of life. Standard patterns of splanchnic oximetry were identified depending on the degree of placental insufficiency.

CONCLUSIONS

There is a correlation between the foetal Doppler and the splanchnic oximetry pattern during the first days of life. Neonates with moderate or severe placental insufficiency have more altered abdominal oximetry patterns, making it a useful technique to evaluate the degree of placental insufficiency and the risk of oral intolerance in small for gestational age neonates.

Echocardiographic Prediction of Left Ventricular Dysfunction After Transcatheter Patent Ductus Arteriosus Closure in Children

Objectives: To evaluate the change of left ventricular (LV) systolic function after transcatheter patent ductus arteriosus (PDA) closure in children, and to identify whether echocardiography parameters could be the predictors of LV dysfunction post-PDA closure if present. Methods: This study enrolled 191 pediatric PDA patients, and all of them underwent successful transcatheter PDA closure between January 2016 and December 2018. The patent ductus arteriosus diameter (PDAd), aortic root diameter (AOd), left atrial diameter (LAd), right ventricular outflow tract dimension (RVOT), LV end-diastolic dimension (LVEDD), and LV end-systolic dimension (LVESD) were all measured by echocardiography at pre-closure, post-closure (within 24 h after the procedure), and follow-up (3 months after the procedure). The ratio of PDAd to AOd (PDAd/AOd), the ratio of LAd to AOd (LAd/AOd), the left ventricular ejection fraction (LVEF), and the fractional shortening (FS) were calculated. Results: The LAd, LVESD, LVEDD, FS, and LVEF decreased significantly in the 24 h after closure, compared to pre-closure levels. However, all echocardiography parameters recovered to pre-closure levels at 3 months after PDA closure in all patients. Moreover, the pre-closure LAd, LVEF, PDAd/AOd, and LAd/AOd were higher in the patients with post-closure LV systolic dysfunction than in those without post-closure LV systolic dysfunction. Furthermore, the pre-closure LVEF, PDAd/AOd, and LAd/AOd were correlated with the post-closure LVEF, and pre-closure LVEF ≤ 66.5%, PDAd/AOd ≥ 0.28, and LAd/AOd ≥ 1.54 predict the post-closure LV systolic dysfunction. Conclusion: Transcatheter closure of PDA causes a significant deterioration in LV systolic function early after PDA closure, which recovered completely within 3 months of post-closure in children. Pre-closure LVEF, PDAd/AOd, and LAd/AOd can be the predictors of post-closure left ventricular systolic dysfunction.

Intrauterine Growth Restriction and Patent Ductus Arteriosus in Very and Extremely Preterm Infants: A Systematic Review and Meta-Analysis

It is generally accepted that intrauterine growth restriction (IUGR) increases morbidity and mortality among very preterm neonates. However, evidence is hampered by the widespread practice of using the terms small for gestational age (SGA) and IUGR as synonyms. We conducted a systematic review of studies reporting on the association between IUGR/SGA and patent ductus arteriosus (PDA). PubMed/MEDLINE and EMBASE databases were searched. Of 993 studies reviewed, 47 (50,790 infants) were included. Studies were combined using a random effects model and sources of heterogeneity were determined by subgroup and meta-regression analyses. Meta-analysis of all included studies showed a significantly reduced risk of PDA in the SGA/IUGR group with an odds ratio (OR) of 0.82, and a 95% confidence interval (CI) of 0.70 to 0.96 (p = 0.015). Of the 47 studies, only 7 used a definition for growth restriction that went beyond birth weight (BW) for gestational age (GA). When pooled, meta-analysis could not demonstrate a significant effect size (OR 1.31, 95% CI 0.75 to 2.27, p = 0.343). Moreover, the significantly reduced risk of PDA was found in the 25 studies defining SGA as BW <10th percentile (OR 0.81, 95% CI 0.66 to 0.98, p = 0.032), but not in the 6 studies defining SGA as BW <3rd (OR 1.09, 95% CI 0.70 to 1.71, p = 0.694), or in the 27 studies using a more refined definition of PDA (i.e., hemodynamically significant PDA or PDA requiring treatment, OR 0.87, 95% CI 0.72 to 1.04, p = 0.133). In addition, we found that GA was significantly higher in the SGA/IUGR group (18 studies, mean difference 0.63 weeks, 95% CI 0.24 to 1.03, p = 0.002). Meta-regression analysis confirmed the correlation between this difference in GA and PDA risk. In summary, we observed marked heterogeneity across studies in the definition of growth restriction and PDA, and we found differences between the control and growth-restricted groups in relevant baseline characteristics, such as GA. Therefore, our meta-analysis could not provide conclusive evidence on the association between growth restriction and PDA.