Prognostic Value of Serial Echocardiography in Hypoplastic Left Heart Syndrome

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.

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.

Conventional echocardiographic parameters at presentation and during follow-up are potential markers for transplant-free survival in children with hypoplastic left heart syndrome.