Abstract 14080: Broadening Indications for Neonatal Balloon Atrial Septostomy in Dextro-Transposition of the Great Arteries Reduce Predictive Value of Fetal Echocardiography

Abstract

Introduction: Neonates with dextro-transposition of the great arteries (d-TGA) require adequate mixing at the atrial level. If not present, these infants experience severe cyanosis, necessitating an urgent balloon atrial septostomy (BAS). Multiple studies have identified various fetal echocardiography (FE) findings as risk factors for postnatal BAS. Anecdotally, the predictive value of these findings remains poor in clinical use. Hypothesis: We aimed to determine the relationship between inter-rater reliability (IRR) of FE BAS predictors and need for postnatal BAS, hypothesizing that IRR would be poor and perhaps contributing to limited predictive value of FE findings. Methods: We identified d-TGA pregnancies followed at our institution between 2012 and 2022, excluding fetuses with large ventricular septal defects and pregnancies that were either terminated or lost to follow up. Three independent readers blinded to BAS outcome assessed 7 FE predictors: pulmonary vein Doppler velocity > 41 cm/sec, reverse flow in patent ductus arteriosus (PDA), restrictive PDA, restrictive patent foramen ovale (PFO), bidirectional PFO flow, flat septum primum, and hypermobile septum primum. IRR was determined with the S metric. Clinical information immediately before BAS was collected to evaluate postnatal physiology. A multivariable logistic regression was used to determine significant associations between FE findings and postnatal BAS. Results: Fifty-six fetuses were included in this study, of whom 25 (45%) underwent BAS. IRR was lowest for PFO flow direction and highest for restrictive PDA, likely due to its rarity. The remainder of FE predictors had either a moderate or substantial level of IRR. The last pre-BAS range of PaO 2 (24-49 mmHg), O 2 saturation (56-86%) and pH (7.18-7.52) reflected variable physiology. Of the 5 FE characteristics that could be included in the regression analysis, none were found to be significantly associated with odds of a BAS. Conclusions: Our results demonstrate substantial but not excellent IRR for current FE BAS predictors, but no significant association between these predictors and postnatal BAS in d-TGA patients. Poor predictive value of FE for postnatal BAS could be impacted by broadening indications for BAS.