Valvuloplasty in 103 fetuses with critical aortic stenosis: outcome and new predictors for postnatal circulation

Abstract

Objectives: To review our experience with fetal aortic valvuloplasty (FAV) in fetuses with critical aortic stenosis (CAS) and evolving hypoplastic left heart syndrome (eHLHS), including short- and medium-term postnatal outcome, and to refine selection criteria for FAV by identifying preprocedural predictors of biventricular (BV) outcome.

Methods: This was a retrospective review of all fetuses with CAS and eHLHS undergoing FAV at our center between December 2001 and September 2020. Echocardiograms and patient charts were analyzed for pre-FAV ventricular and valvular dimensions and hemodynamics and for postnatal procedures and outcomes. The primary endpoints were type of circulation 28 days after birth and at 1 year of age. Classification and regression-tree analysis was performed to investigate the predictive capacity of pre-FAV parameters for BV circulation at 1 year of age.

Results: During the study period, 103 fetuses underwent 125 FAVs at our center, of which 87.4% had a technically successful procedure. Technical success per fetus was higher in the more recent period (from 2014) than in the earlier period (96.2% (51/53) vs 78.0% (39/50); P = 0.0068). Eighty fetuses were liveborn after successful intervention and received further treatment. BV outcome at 1 year of age was achieved in 55% of liveborn patients in our cohort after successful FAV, which is significantly higher than the BV-outcome rate (23.7%) in a previously published natural history cohort fulfilling the same criteria for eHLHS (P = 0.0015). Decision-tree analysis based on the ratio of right to left ventricular (RV/LV) length combined with LV pressure (mitral valve regurgitation maximum velocity (MR-Vmax)) had a sensitivity of 96.97% and a specificity of 94.44% for predicting BV outcome without signs of pulmonary arterial hypertension at 1 year of age. The highest probability for a BV outcome was reached for fetuses with a pre-FAV RV/LV length ratio of < 1.094 (96.4%) and for those fetuses with a RV/LV length ratio ≥ 1.094 to < 1.135 combined with a MR-Vmax of ≥ 3.14 m/s (100%).

Conclusions: FAV could be performed with high success rates and an acceptable risk with improving results after a learning curve. Pre-FAV RV/LV length ratio combined with LV pressure estimates were able to predict a successful BV outcome at 1 year of age with high sensitivity and specificity. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Keywords: congenital heart disease; critical aortic stenosis; evolving hypoplastic left heart syndrome; fetal cardiac intervention; fetal cardiology.

Figure 1

Measurement of ventricular and valvular dimensions in the four‐chamber view at end‐diastole in a 27‐week fetus with critical aortic stenosis and evolving hypoplastic left heart syndrome. The lengths of the left (LV) and right (RV) ventricles were measured from the respective valve annulus to the endocardium at the apex. In cases of globular LV, the line for measurement of RV length did not cross the septum. MV, mitral valve; TV, tricuspid valve.

Figure 2

Flowchart showing outcome of fetuses with critical aortic stenosis (CAS) and evolving hypoplastic left heart syndrome (eHLHS) that underwent fetal aortic valvuloplasty (FAV). *Including one patient after hybrid repair. †Including five patients with biventricular (BV) to univentricular (UV) conversion. IUD, intrauterine death.

Figure 3

Kaplan–Meier curves comparing survival of patients with critical aortic stenosis and evolving hypoplastic left heart syndrome who were liveborn after technically successful fetal aortic valvuloplasty, overall () and according to whether they had a biventricular () or univentricular () management after birth. Actual number of individuals included at each time period is documented below curves. Time zero represents birth. Comparison using Mantel–Cox log‐rank test showed no significant difference in survival between the two groups (df = 1; χ‐square = 0.041; P = 0.8395).

Figure 4

Classification and regression‐tree analysis for prediction of biventricular (BV) outcome at 1 year of age in: (a) 51 liveborn patients who had technically successful (TS) fetal aortic valvuloplasty (FAV) performed after 2010; and (b) 28 liveborn patients who underwent TS‐FAV before 28 + 0 weeks' gestation. LV, left ventricle; MR, mitral valve regurgitation; RV, right ventricle; Vmax, maximum velocity.