Abstract 18041: Fetal Right - Left Heart Discrepancy: Predictive Factors for Critical Left Heart Obstruction
Background: Right-left heart discrepancy (RLD) with right dominance is frequently seen in fetuses with significant left heart obstruction (LHO) requiring surgery in the newborn period. RLD can also be seen in normal fetuses. The goal of this study was to identify features of RLD that predict critical LHO requiring early postnatal surgery.
Methods: Our fetal database was retrospectively reviewed, and fetuses with RLD concerning for LHO were identified. Left and right heart variables were measured. Cases were divided into 2 groups based on the postnatal outcome: Surgery (S) group if there was critical LHO requiring surgery in the newborn period, and No Surgery (NS) group if no newborn surgery for LHO was needed. Measurement Z-scores (for gestational age) and ratios of right-left heart variables were compared between groups. The predictive values of significant variables for postnatal outcome were assessed.
Results: Sixty eight fetuses were studied: 41 NS and 27 S. Postnatally, in the NS cases, 28 were normal, 3 had mild arch hypoplasia not needing intervention, 7 had VSD, and 3 had anomalous pulmonary venous return. In the S cases, 24 had critical arch obstruction with arch repair and 3 had HLHS with single ventricle palliation. Z-scores and ratios between groups are shown in the Table. MV Z-score (MV-Z) was smaller and MPA Z-score (MPA-Z) were larger in S Group (p <0.0001, Table). MV-Z, MPA-Z, and ascending aorta to MPA ratio (AAo/MPA) were the strongest predictive factors for critical LHO (areas under ROC curve: 0.98, 0.89 and 0.81, respectively). MV-Z of <-2.0 had 95% sensitivity and 80% specificity for critical LHO.
Conclusions: Fetal RLD is an important indicator of significant newborn LHO. Cases with critical LHO have smaller MV-Z and larger MPA-Z. A MV-Z of <-2.0 had 95% sensitivity and 80% specificity for critical LHO. The MV-Z, MPA-Z and AAo/MPA ratio have the highest predictive value to discriminate cases of critical LHO likely to need surgery in the newborn period.
- © 2012 by American Heart Association, Inc.