Prognostic Value of Serial Echocardiography in Hypoplastic Left Heart Syndrome.

Background: Hypoplastic left heart syndrome (HLHS) carries a high mortality. The prognostic value of echocardiographic variables at presentation and the importance of serial data are poorly explored. Methods and Results: We retrospectively analyzed longitudinal clinical and echocardiographic parameters of children with hypoplastic left heart syndrome. The primary outcome was time to death or transplant after stage-1 surgery, right censored at stage 3 surgery, accounting for sequential surgical procedures. Univariable and multivariable analysis identified risk factors for transplant or mortality. Time-dependent trends in echo parameters stratified by patient survival were explored using nonparametric methods. In total 67 children with hypoplastic left heart syndrome were included. The 10-week, 20-week, and 1-year survival proportions were 77.6% (66-86), 68.7% (56-78), and 54.1% (41-65), respectively. At presentation, multivariable analysis identified a thicker interventricular septum (hazard ratio [HR], 1.64; P=0.007) to be associated with increased risk for transplant/death, whereas higher tricuspid valve annular planar systolic excursion z score (HR, 0.61; P=0.003) was associated with reduced risk of mortality/transplant. After stage-1, higher body surface area-indexed right ventricular end-systolic area (HR, 1.52; P=0.02), lower fractional area change (HR, 1.18; P=0.01), and qualitatively decreased right ventricular function (HR, 2.55; P=0.08) were associated with increased risk of transplant-free mortality, censored at stage 3. Higher body surface area-indexed right ventricular end-diastolic area (HR, 0.76; P=0.04) and better tricuspid valve annular planar systolic excursion z score (HR, 0.49; P=0.01) were associated with lower mortality/transplant. During follow-up, right ventricular dilation, dysfunction, and tricuspid regurgitation improved in transplant-free survivors and worsened in those transplanted or who died. Conclusions: Conventional echocardiographic parameters at presentation and during follow-up are potential markers for transplant-free survival in children with hypoplastic left heart syndrome.