PDA: Does it matter?

[Risk factors for the failure of ibuprofen treatment in preterm infants with hemodynamically significant patent ductus arteriosus]

OBJECTIVES

To investigate the risk factors for the failure of ibuprofen treatment in preterm infants with hemodynamically significant patent ductus arteriosus (hsPDA).

METHODS

A retrospective collection of clinical data was conducted on preterm infants with a gestational age of <34 weeks who were diagnosed with hsPDA and treated at the Department of Neonatology, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, from January 2018 to June 2023. The subjects were divided into two groups based on the treatment approach: the ibuprofen group (95 cases) and the ibuprofen plus surgery group (44 cases). The risk factors for the failure of ibuprofen treatment in preterm infants with hsPDA were identified by binary logistic regression analysis.

RESULTS

The binary logistic regression analysis revealed that an increased diameter of the ductus arteriosus, a resistance index (RI) value of the middle cerebral artery ≥0.80, and prolonged total invasive mechanical ventilation time were risk factors for the failure of ibuprofen treatment in preterm infants with hsPDA (P<0.05). Receiver operating characteristic curve analysis showed that a ductus arteriosus diameter >2.85 mm, a middle cerebral artery RI value ≥0.80, and a total invasive mechanical ventilation time >16 days had significant predictive value for the failure of ibuprofen treatment in preterm infants with hsPDA (P<0.05). The combined predictive value of these three factors was the highest, with an area under the curve of 0.843, a sensitivity of 86.5%, and a specificity of 75.0% (P<0.05).

CONCLUSIONS

A ductus arteriosus diameter >2.85 mm, a middle cerebral artery RI value ≥0.80, and a total invasive mechanical ventilation time >16 days are risk factors for the failure of ibuprofen treatment in preterm infants with hsPDA, and they are of significant predictive value for the necessity of surgical treatment following the failure of ibuprofen treatment.

Hemodynamic Melody of Postnatal Cardiac and Pulmonary Development in Children with Congenital Heart Diseases

Hemodynamics is the eternal theme of the circulatory system. Abnormal hemodynamics and cardiac and pulmonary development intertwine to form the most important features of children with congenital heart diseases (CHDs), thus determining these children's long-term quality of life. Here, we review the varieties of hemodynamic abnormalities that exist in children with CHDs, the recently developed neonatal rodent models of CHDs, and the inspirations these models have brought us in the areas of cardiomyocyte proliferation and maturation, as well as in alveolar development. Furthermore, current limitations, future directions, and clinical decision making based on these inspirations are highlighted. Understanding how CHD-associated hemodynamic scenarios shape postnatal heart and lung development may provide a novel path to improving the long-term quality of life of children with CHDs, transplantation of stem cell-derived cardiomyocytes, and cardiac regeneration.

Procalcitonin-Based Antibiotic Use for Neonatal Early-Onset Bacterial Infections: Pre- and Post-Intervention Clinical Study

We previously reported the 95th percentile cutoff value of the serum procalcitonin (PCT) reference curve for diagnosing early-onset bacterial infection. We aimed to verify the effectivity of these novel diagnostic criteria by comparing antibiotic use and incidence of early-onset bacterial infection between pre- and post-introduction periods. We included newborns admitted to our neonatal intensive care unit who underwent blood tests within 72 h after birth between 2018 and 2022. The neonates were divided into the pre-intervention (admitted before the introduction, n = 737) or post-intervention (admitted after the introduction, n = 686) group. The days of antibiotics therapy (DOT) per 1000 patient days up to 6 days after birth, percentage of antibiotic use, and incidence of early-onset bacterial infection were compared between the groups. The post-intervention group had significantly lower DOT per 1000 patient days (82.0 days vs. 211.3 days, p < 0.01) and percentage of newborns receiving antibiotics compared with the pre-intervention group (79 (12%) vs. 280 (38%), respectively, p < 0.01). The incidence of early-onset bacterial infections did not differ between the groups (2% each, p = 0.99). In conclusion, our diagnostic criteria using the 95th percentile cutoff value of the serum PCT reference curve for early-onset bacterial infection were proven safe and effective, promoting appropriate use of antibiotics.

Age-Related Prevalence of Open Ductus Arteriosus in Full-Term Newborns

BACKGROUND

The ductus arteriosus is part of the fetal circulation. Normally, the vessel closes during the cardiac transition. Delayed closure is associated with complications. The aim of this study was to evaluate the age-related prevalence of open ductus arteriosus in full-term neonates.

METHODS

Echocardiograms were collected in the population study, the Copenhagen Baby Heart Study. The present study included full-term neonates with an echocardiogram performed within 28 days after birth. All echocardiograms were reviewed to assess ductus arteriosus patency.

RESULTS

A total of 21,649 neonates were included. In neonates examined at day zero and day seven, an open ductus arteriosus was found in 36% and 0.6%, respectively. Beyond day seven, the prevalence remained stable at 0.6%.

CONCLUSION

More than one-third of full-term neonates had an open ductus arteriosus on the first day of life, declining rapidly within the first week and stabilizing below 1% after day seven.

Surgical ligation, not transcatheter closure, associated with a higher severity of bronchopulmonary dysplasia in extremely preterm infant intervened for patent ductus arteriosus

OBJECTIVE

Patent ductus arteriosus (PDA) is a common complication among premature infants, which may be responsible for prematurity-related complications such as bronchopulmonary dysplasia (BPD). It is unclear whether different interventional methods contribute to the severity of BPD, given the original National Institute of Child Health and Human Development (NICHD) 2001 definition. To date, surgical ligation and the transcatheter approach have been equally successful in premature infants with hemodynamically significant PDA after medical treatment failure. Immediate improvement in the respiratory condition has been reported after transcatheter closure. However, the short-term pulmonary outcome has not been clarified yet.

METHODS

This retrospective study investigated infants born with a body weight <1000 g and who underwent either surgical ligation or transcatheter closure of PDA in a single tertiary institution. The infants were divided into groups according to the type of procedure (surgical ligation or transcatheter occlusion). The primary outcome was the severity of BPD at discharge or at a postmenstrual age of 36 weeks. The outcome was analyzed with logistic regression.

RESULTS

Forty-four patients met the inclusion criteria, of whom 14 underwent transcatheter occlusion and 30 underwent surgical ligation. The overall birth body weights and gestational age ranges were not different. The univariate model revealed an association between the procedure type and BPD severity. After adjusting for confounders, the multivariate model confirmed associations between BPD severity and procedure type and severe respiratory distress syndrome requiring surfactant.

CONCLUSION

Compared with the transcatheter approach, surgery for PDA in extremely preterm infants is associated with severe BPD at discharge. Further large-scale studies are needed to determine the exact mechanism.

The chance of spontaneous patent ductus arteriosus closure in preterm infants born before 32 weeks of gestation is high and continues to increase until 5 years of follow-up

AIM

The primary aim was to estimate premature infants' spontaneous patent ductus arteriosus closure rate. Secondly, to identify criteria associated with the chance of spontaneous closure.

METHODS

We performed a retrospective cohort study of 167 infants born before 32 weeks of gestation and diagnosed with a patent ductus arteriosus between 1 January 2008 and 31 December 2017. The spontaneous patent ductus arteriosus closure event rate was evaluated using the Kaplan-Meier estimator.

RESULTS

The spontaneous closure rate within the first year of life was 66% (95% CI 58%-73%), increasing to 80% (95% CI 72%-86%) five years after birth. When including both spontaneous closure and closure following treatment, 96% (95% CI 86%-100%) closed within 5 years after birth. The chance of spontaneous closure was reduced in the case of a large patent ductus arteriosus: OR 0.16 (95% CI 0.05-0.52), left atrial enlargement: OR 0.16 (95% CI 0.05-0.51), and pulmonary hypertension: OR 0.23 (95% CI 0.07-0.74).

CONCLUSION

The chance of spontaneous closure in premature infants born between 23 and 32 weeks of gestation was high, and the incidence continued increasing until 5 years of follow-up.

[Timing of surgical ligation of patent ductus arteriosus in very low birth weight infants]

OBJECTIVES

To study the effect of timing of surgical ligation of patent ductus arteriosus (PDA) on the prognosis of very low birth weight infants (VLBWI).

METHODS

The medical data of VLBWI who underwent transthoracic ligation for PDA from June 2018 to May 2021 were reviewed retrospectively. The infants were divided into early ligation group (≤21 days of age) and late ligation group (>21 days of age) based on the age of ligation. The two groups were compared in terms of perioperative clinical features, complications, and mortality. The risk factors for early surgical ligation were analyzed.

RESULTS

A total of 72 VLBWI were enrolled, with 19 infants (26%) in the early ligation group and 53 infants (74%) in the late ligation group. There were significant differences in birth weight, gestational age, weight at operation, days of age at operation, rates of preoperative invasive and noninvasive mechanical ventilation, incidence rate of pulmonary hemorrhage, incidence rate of hypotension, preoperative PDA internal diameter (mm/kg), intraoperative PDA external diameter (mm/kg), incidence rate of post-ligation cardiac syndrome, and duration of postoperative invasive mechanical ventilation between the two groups (P<0.05). A binary logistic regression analysis showed that pulmonary hemorrhage was an indication of early surgical ligation of PDA (P<0.05). There were no significant differences in the incidence rates of post-operative complications and the mortality rate between the early ligation and late ligation groups.

CONCLUSIONS

Early surgical ligation may be performed for VLBWI who are experiencing pulmonary hemorrhage and hemodynamically significant PDA confirmed by cardiac ultrasound after birth. However, post-ligation cardiac syndrome should attract enough attention. In addition, early surgical ligation of PDA does not increase the risk of surgery-related and long-term complications or death, indicating that it is a safe and feasible treatment option.

Brain and renal oxygenation measured by NIRS related to patent ductus arteriosus in preterm infants: a prospective observational study

Background

Patent ductus arteriosus (PDA) is common among preterm neonates. Haemodynamically significant ductus arteriosus (hsPDA) can cause ductal steal and contribute to poor outcomes. Our aim was to evaluate ductus arteriosus patency and significance using two-site near-infrared spectroscopy (NIRS) measurements in preterm infants older than 72 h as a supplemental tool to echocardiography.

Methods

In this prospective observational study, 123 preterm infants (gestational age (GA) < 32 weeks, birth weight < 1500 g) were enrolled. Sixty-four newborns had closed ductus arteriosus (noPDA), and 41 and 18 patients were assigned to the PDA and hsPDA groups, respectively, per predefined echocardiographic criteria. Cerebral and renal oxygenation were assessed during NIRS monitoring.

Results

A higher renal mean (±SD) regional tissue oxygen saturation (rSpO₂) (76.7 (±7.64)) was detected in the noPDA group than in the PDA (71.7 (±9.02)) and hsPDA (67.4 (±13.48)) groups (p < 0.001). Renal fractional tissue oxygen extraction (FTOE) (0.18 (±0.079)) was lower in the noPDA group than in the PDA (0.23 (±0.092)) and hsPDA (0.24 (±0.117))0.117 groups (p = 0.002). Cerebral oxygenation was significantly lower in the hsPDA group (77.0 (±5.16)) than in the noPDA (79.3 (±2.45)) and PDA (79.7 (±2.27)) groups (p = 0.004). There was no significant difference in cerebral fractional tissue oxygen extraction (FTOE) between any of the groups.

Conclusions

Our results suggest that renal oxygenation is affected by ductus patency in preterm infants older than 72 h. Significant differences in cerebral oxygenation were observed between the hsPDA group and the PDA and noPDA groups.

Trial registration

ClinicalTrials.gov Identifier: NCT04295395. Registration date: 4 March 2020. This study was retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04295395.

The molecular mechanisms of oxygen-sensing in human ductus arteriosus smooth muscle cells: A comprehensive transcriptome profile reveals a central role for mitochondria

The ductus arteriosus (DA) connects the fetal pulmonary artery and aorta, diverting placentally oxygenated blood from the developing lungs to the systemic circulation. The DA constricts in response to increases in oxygen (O2) with the first breaths, resulting in functional DA closure, with anatomic closure occurring within the first days of life. Failure of DA closure results in persistent patent ductus arteriosus (PDA), a common complication of extreme preterm birth. The DA's response to O2, though modulated by the endothelium, is intrinsic to the DA smooth muscle cells (DASMC). DA constriction is mediated by mitochondrial-derived reactive oxygen species, which increase in proportion to arterial partial pressure of oxygen (PaO2). The resulting redox changes inhibit voltage-gated potassium channels (Kv) leading to cell depolarization, calcium influx and DASMC constriction. To date, there has not been an unbiased assessment of the human DA O2-sensors using transcriptomics, nor are there known molecular mechanisms which characterize DA closure. DASMCs were isolated from DAs obtained from 10 term infants at the time of congenital heart surgery. Cells were purified by flow cytometry, negatively sorting using CD90 and CD31 to eliminate fibroblasts or endothelial cells, respectively. The purity of the DASMC population was confirmed by positive staining for α-smooth muscle actin, smoothelin B and caldesmon. Cells were grown for 96 h in hypoxia (2.5% O2) or normoxia (19% O2) and confocal imaging with Cal-520 was used to determine oxygen responsiveness. An oxygen-induced increase in intracellular calcium of 18.1% ± 4.4% and SMC constriction (-27% ± 1.5% shortening) occurred in all cell lines within five minutes. RNA sequencing of the cells grown in hypoxia and normoxia revealed significant regulation of 1344 genes (corrected p < 0.05). We examined these genes using Gene Ontology (GO). This unbiased assessment of altered gene expression indicated significant enrichment of the following GOterms: mitochondria, cellular respiration and transcription. The top regulated biologic process was generation of precursor metabolites and energy. The top regulated cellular component was mitochondrial matrix. The top regulated molecular function was transcription coactivator activity. Multiple members of the NADH-ubiquinone oxidoreductase (NDUF) family are upregulated in human DASMC (hDASMC) following normoxia. Several of our differentially regulated transcripts are encoded by genes that have been associated with genetic syndromes that have an increased incidence of PDA (Crebb binding protein and Histone Acetyltransferase P300). This first examination of the effects of O2 on human DA transcriptomics supports a putative role for mitochondria as oxygen sensors.

Massive Gastric Hemorrhage after Indomethacin Therapy: A Rare Presentation and Critical Management in an Extremely Preterm Infant

Indomethacin has been widely used in preterm infants with hemodynamically significant patent ductus arteriosus (PDA). Gastrointestinal complications of indomethacin have been reported in 5% of treated neonates. However, massive gastric mucosa hemorrhage is a rarely reported complication. To the best of our knowledge, the infant in this report is the smallest reported in the literature to have undergone successful surgery for such a complication. A male preterm infant weighing 566 g was born at 25^2/7 weeks of gestational age without a complicated maternal history. Soon after birth, he received nasal noninvasive respiratory support and minimal feeding. PDA was observed since the first day of life (DOL), treatments were initiated on the second DOL for the hemodynamical significance, and PDA was closed after two courses of indomethacin therapy (0.2 mg/kg). At midnight on the seventh DOL, generalized pallor, bloody gastric drainage, and a distended stomach were observed. Massive gastric bleeding was suspected. He suffered from intermittent hypotension, which was corrected with blood products and fluid resuscitation under monitoring with a radial arterial line. Gastric lavage with cooling saline was performed twice but in vain. Prior to surgical consultation, intravascular volume transfusion was given twice. An exploratory laparotomy was arranged after obtaining the parents' consent. Blood oozing from the gastric mucosa was observed through gastrostomy and was successfully stopped via epinephrine-soaked gauze compression. After the operation, his clinical course remained uneventful, and he was discharged without neurological anomaly at two-year follow-up. Physicians need to be cautious of indomethacin's effect on platelet dysfunction in preterm infants with multiple predisposing factors. The tendency for mucosal bleeding should be continuously monitored after indomethacin therapy.

Morbidity associated with patent ductus arteriosus in preterm newborns: a retrospective case-control study

INTRODUCTION

Association between persistency of a patent ductus arteriosus (PDA) and morbidity in preterm newborns is still controversial. We aimed to investigate the relation between PDA and morbidity in a large retrospective study.

METHODS

A case-control study including neonates consecutively admitted to the Neonatal Intensive Care Unit (NICU), with gestational age (GA) < 32 weeks or body birth weight (BW) < 1500 g, over a 5-year period. Newborns were divided into Cases and Controls, according with the presence or absence of a hemodynamically significant PDA (hs-PDA).

RESULTS

We enrolled 85 Cases and 193 Controls. Subjects with hs-PDA had significantly (p < 0.001) lower GA (26.7 w, 95%CI 27.1-28.0 vs. 30.1 w, 95%CI 29.7-30.4), BW (1024 g, 95% CI 952-1097 vs. 1310 g 95%CI 1263-1358) and an increased morbidity (60.0% vs. 18.7%). In a sub-group of extremely preterm newborns (GA ≤ 28 weeks and BW ≤ 1000 g), the rate of bronchopulmonary dysplasia (BPD) was significantly increased in Cases (31.7%) compared with Controls (5.9%, p = 0.033). Multivariate analysis showed that morbidity significantly depended on hs-PDA, GA and BW, and that, in extremely preterms, the hs-PDA represented an independent risk factor for BPD.

CONCLUSIONS

Occurrence of the main morbidities of prematurity depended by hs-PDA, in association with GA, BW, and use of prenatal steroids. In extremely premature babies, hs-PDA is a risk factor for BPD, one of the most important morbidity of prematurity, independently by other confounding variables.

Role of Extracellular Matrix in Pathophysiology of Patent Ductus Arteriosus: Emphasis on Vascular Remodeling

The ductus arteriosus (DA) is a shunt vessel between the aorta and the pulmonary artery during the fetal period that is essential for the normal development of the fetus. Complete closure usually occurs after birth but the vessel might remain open in certain infants, as patent ductus arteriosus (PDA), causing morbidity or mortality. The mechanism of DA closure is a complex process involving an orchestration of cell-matrix interaction between smooth muscle cells (SMC), endothelial cells, and extracellular matrix (ECM). ECM is defined as the noncellular component secreted by cells that consists of macromolecules such as elastin, collagens, proteoglycan, hyaluronan, and noncollagenous glycoproteins. In addition to its role as a physical scaffold, ECM mediates diverse signaling that is critical in development, maintenance, and repair in the cardiovascular system. In this review, we aim to outline the current understandings of ECM and its role in the pathophysiology of PDA, with emphasis on DA remodeling and highlight future outlooks. The molecular diversity and plasticity of ECM present a rich array of potential therapeutic targets for the management of PDA.