Abstract 10723: Fetal Echocardiographic Assessment of Right Ventricular and Tricuspid Valve Function in Hypoplastic Left Heart Syndrome: Correlation with Postnatal Outcomes

Abstract

Introduction: Hypoplastic left heart syndrome (HLHS) carries significant morbidity and mortality. Transthoracic echocardiogram (echo) assessment of right ventricular (RV) function and tricuspid regurgitation (TR) correlate with HLHS outcomes. There are limited reports on RV function and TR in fetal HLHS and postnatal outcomes. We aim to correlate RV function and TR on fetal-echo (F-echo) with transplant-free survival (survival), hospital length of stay after initial surgery (LOS), and timing of Glenn (BDG) in HLHS patients. Methods: Imaging and clinical data of fetuses diagnosed with HLHS between February 2014 and September 2020 at our institution were retrospectively reviewed. Measurements of RV myocardial performance index (MPI) and fractional area change (FAC) were made on initial F-echo. The RV shortening fraction (SF), presence/degree of TR, and RV size by diastolic short-axis dimension were recorded. Postnatal outcomes included survival, LOS and age at BDG. Early BDG was a repair at <4 months. Mann-Whitney U test correlated F-echo measures and postnatal outcomes. Results: F-echo was available in 69 subjects; 22 excluded for termination/fetal demise, 9 for genetic syndromes, resulting in 38 subjects. Mean age at initial F-echo was 31.4±0.9wks, 11 referred >30 weeks from regional cardiologists (adjusted mean age 23.1±0.4wks). Subject age at time of review ranged from 7 months to 6.5 years. Eight subjects died (median age 2 months) and 3 required transplant (median age 8 months). F-echo RV MPI was significantly higher (0.372±0.09;p=0.005) and RV FAC was significantly lower (43%±6.4%;p=0.016) in HLHS non-survivors versus survivors. Fetal RV size and presence of TR were not significantly different. Subjects with initial LOS >30 days were more likely to have fetal TR (p<0.001) and RV dilation (p=0.019), but no significant RV MPI and FAC difference. No fetal measures correlated with need for an early BDG. Conclusion: F-echo evaluation of RV MPI and FAC in HLHS correlates with transplant-free survival. Presence of fetal TR and RV dilation correlate with a longer LOS. F-echo measures of RV function and TR function may inform prenatal counseling and postnatal outcomes for fetal HLHS.