Fetal Echocardiographic Evaluation of Tricuspid Valve and Right Ventricular Function including Global Longitudinal Strain in Hypoplastic Left Heart Syndrome and Association with Postnatal Outcomes

Background: Despite significant advancements in the care of patients with hypoplastic left heart syndrome (HLHS) morbidity and mortality remain high. Postnatal right ventricular dysfunction and tricuspid regurgitation (TR) is associated with worse outcomes in HLHS. We aim to determine if right ventricle functional parameters and TR on fetal echocardiogram are associated with postnatal outcomes in HLHS patients. Methods: Retrospective review was performed on all fetuses with HLHS from 2014–2022 at our institution. Initial and follow up fetal echocardiogram measurements of right ventricular myocardial performance index (MPI), fractional area change (FAC) and global longitudinal strain (GLS) were retrospectively measured. The presence and severity of TR was recorded from the fetal echocardiogram reports. Postnatal outcomes including transplant-free survival, hospital length of stay > 30 days after initial palliation and need for bidirectional Glenn at < 4 months were reviewed. Results: Forty-three subjects met inclusion criteria. Mean gestational age at presentation was 26.1 ± 5.9 weeks. Nine subjects died and 3 required transplants. Initial fetal echocardiogram MPI was significantly lower (better) (0.36 ± 0.06 vs 0.44 ± 0.11; p = < 0.001) and FAC was significantly higher (better) 45 ± 6% vs 40 ± 8%; p = 0.035) in transplant-free survivors. Fetal right ventricular GLS and presence of TR were not associated with any postnatal outcomes. Conclusion: In fetuses with HLHS, abnormal MPI and right ventricular FAC are associated with decreased transplant-free survival. There was no observed association between GLS and any of the postnatal variables. To our knowledge this is the first study examining fetal right ventricular GLS in HLHS patients and its link to postnatal outcomes.