Serial changes in longitudinal strain are associated with outcome in children with hypoplastic left heart syndrome

Introduction: Hypoplastic Left Heart Syndrome (HLHS) has high mortality and morbidity and systemic right ventricle (RV) dysfunction may play a key-role. Study aim is to evaluate the accuracy of speckle-tracking echocardiographic (STE) assessment of RV deformation and 2D standard echo parameters in predicting outcome in HLHS patients.

Methods: We studied 27 HLHS patients (17 male) who successfully completed Norwood palliation. All the patients underwent in-hospital interstage stay. Serial echocardiographic assessment was performed: baseline, one-month after Norwood, three-months after Norwood, one-week before bidirectional cavopulmonary anastomosis (BCPA) and two-months after BCPA. From the apical view we measured: tricuspid annulus peak systolic excursion (TAPSE), fractional area change (FAC), longitudinal strain (LS) and strain rate (LSR).

Results: After a mean follow-up of 1.18 (± 1.16) years, 8 out of 27 of the included patients met the composite endpoint of death/heart transplant (HT). At pre-Norwood assessment, there was no difference in echo measurements between survivors and patients with events. In death/HT group TAPSE and LS declined already one-month after Norwood procedure: TAPSE ≤5 mm had good sensitivity (85.71%) and moderate specificity (63.16%) for death/HT (AUC = 0.767); a decrease of LS > 8.7% vs baseline showed 100% sensitivity and 84.21% specificity for death/HT (AUC = 0.910). At multivariate analysis, one-month-after-Norwood LS drop >8.7% was the best predictor of outcome (P = 0.01).

Conclusions: RV dysfunction in HLHS carries prognostic value. Our findings encourage serial measurements of RV function to identify the subgroup of HLHS patients at higher risk. In our experience, ∆ LS showed the best predictive value.