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

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.

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).

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).

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.