TnECHO-Qc Collaborative Day - 2026

Dr Gabriel Altit

Dr Brahim Bensouda

Dr Christine Drolet

Dr Audrey Hébert

Dr Anie Lapointe

Dr Nina Nouraeyan

Dr Sarah Spénard

Dr Andréanne Villeneuve

Dexamethasone is associated with Ductal Closure in Extremely Preterm Infants with Evolving Lung Disease 

Phoenix Plessas-Azurduy1, Joshua Hazan Mea2, Thomas Sonea3, Pasinee Kanaprach4, Sariya Sahussarungsi5, Carolina Michel Macias6, Shiran Sara Moore7, Punnanee Wutthigate8, Jessica Simoneau4, Daniela Villegas Martinez4, Andréanne Villeneuve9, Anie Lapointe9, Guilherme Sant’Anna4, Gabriel Altit4 

1Division of Clinical & Translational Research, McGill University, Montreal, QC, Canada, 2Division of Neonatology, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada, 3Faculté de médecine, Université de Montréal, Montreal, QC, Canada, 4Division of Neonatology, Department of Pediatrics, Montreal Children's Hospital, Montreal, QC, Canada, 5Department of Pediatrics, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand, 6Universidad Autónoma de Querétaro, Facultad de Medicina, Querérato, Mexico, 7Division of Neonatology, Department of Pediatrics, Dana Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 8Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, 9Division of Neonatology, Department of Pediatrics, CHU Sainte-Justine, Université de Montréal, QC, Canada. 

BACKGROUND: Dexamethasone (DEXA) is frequently administered to extremely preterm infant with evolving lung disease, yet its influence on patent ductus arteriosus (PDA) dynamics remains poorly understood, especially in neonatal intensive care units practicing conservative PDA management.  

OBJECTIVE: To evaluate the trajectory of PDA size and closure rates following DEXA administration. We hypothesized that DEXA treatment would be associated with a progressive ductal constriction an increased likelihood of closure. 

METHODS: We conducted a prospective observational cohort study of infants born at <29 weeks’ gestation (GA) who received DEXA for treatment of severe lung injury/inflammation. Serial echocardiographic images were obtained at seven predefined timepoints: baseline (prior to DEXA initiation), days 3, 7, and 14 of treatment, 1- and 2-weeks post-therapy, and at 36 weeks corrected GA. PDA diameter and flow pattern were measured by a blinded evaluator using standardized protocols. Longitudinal data were analyzed using a generalized estimating equations (GEE) model or a random mixed effects model. 

RESULTS: Between 2021-2024, 57 neonates were enrolled, of which 53 had a PDA diagnosed at baseline (mean GA 24.3 ± 5.3 weeks, birth weight 759 ± 192g, 59% male, 79% inborn) - Table 1. By day 7 of DEXA, 62% of the PDAs were closed/restrictive; by one week post-DEXA cessation 76% were closed or restrictive (Figure 1). With each timepoint, there was an increase in the likelihood of PDA closure (b: 0.35, p <0.001). At 36 weeks corrected GA, 95% of infants demonstrated complete closure or restrictive PDA. Only 5 infants received pharmacological PDA treatment and 1 PDA was surgically ligated. 

CONCLUSION: DEXA administration was associated with a consistent temporal reduction in PDA size and patency. Beyond its pulmonary benefits, DEXA may support spontaneous ductal closure in extremely preterm infants through favorable cardiovascular remodeling 

Title: Fetal Cardiac Structure and Myocardial Deformation as Predictors of Balloon Atrial Septostomy in D-Transposition of the Great Arteries

Authors: Flavia Voiculescu, Alexie Fonta-Holder, Daniela Villegas-Martinez, Wadi Mawad, Anie Lapointe, Marie-Josée Raboisson, Gabriel Altit 

Background: Dextro-transposition of the great arteries (d-TGA) is a critical congenital heart disease characterized by parallel systemic and pulmonary circulations, placing affected neonates at high risk of profound hypoxemia when postnatal mixing is inadequate. Balloon atrial septostomy (BAS) is frequently required in the immediate neonatal period; however, accurately predicting the need and urgency of this intervention prenatally remains challenging. Previous studies have identified fetal echocardiographic markers such as foramen ovale (FO) size and atrial septal mobility as highly specific predictors, but with limited sensitivity. A more comprehensive assessment of fetal cardiac structure and myocardial performance may improve prenatal risk stratification in this population.

Methods: We designed a multicenter retrospective case–control study including fetuses with isolated d-TGA evaluated at the McGill University Health Centre and CHU Sainte-Justine between 2015 and 2025, alongside gestational age–matched fetal controls without congenital anomalies. Fetal and neonatal echocardiographic data will be retrieved from institutional databases. Echocardiographic measures of systolic function will be complemented by speckle-tracking echocardiography to assess ventricular deformation. Clinical and perinatal data will be obtained through structured chart review. Fetuses with d-TGA will be stratified based on postnatal requirement for BAS.

Anticipated Impact: This study aims to improve prenatal identification of fetuses at high risk for urgent postnatal BAS by integrating myocardial deformation analysis with established echocardiographic markers. Improved risk stratification may inform delivery planning, optimize neonatal management, and ultimately reduce hypoxic morbidity in newborns with d-TGA.