Fetal Aortic Valvuloplasty for Evolving Hypoplastic Left Heart Syndrome: A Decision Analysis.

BACKGROUND: Fetal aortic valvuloplasty (FAV) may prevent progression of midgestation aortic stenosis to hypoplastic left heart syndrome. However, FAV has well-established risks, and its survival benefit remains unknown. Our primary aim was to determine whether FAV for midgestation aortic stenosis increases survival from fetal diagnosis to age 6 years. METHODS AND RESULTS: We performed a retrospective analysis of 143 fetuses who underwent FAV from 2000 to 2017 and a secondary analysis of the Pediatric Heart Network Single Ventricle Reconstruction trial. Using these results, we developed a decision model to estimate probability of transplant-free survival from fetal diagnosis to age 6 years and postnatal restricted mean transplant-free survival time. FAV was technically successful in 84% of 143 fetuses with fetal demise in 8%. Biventricular circulation was achieved in 50% of 111 live-born infants with successful FAV but in only 16% of the 19 patients with unsuccessful FAV. The model projected overlapping probabilities of transplant-free survival to age 6 years at 75% (95% CI, 67%-82%) with FAV versus 72% (95% CI, 61%-82%) with expectant fetal management, resulting in a restricted mean transplant-free survival time benefit of 1.2 months. When limiting analyses to the improved FAV experience since 2009 to reflect current practice, (probability of technical success [94%], fetal demise [4%], and biventricular circulation [66%]), the model projected that FAV increased the probability of survival to age 6 years to 82% (95% CI, 73%-89%). Expectant management is favored if risk of fetal demise exceeded 12% or probability of biventricular circulation fell below 26%, but FAV remained favored over plausible recent range of technical success. CONCLUSIONS: Our model suggests that FAV provides a modest, medium-term survival benefit over expectant fetal management. Appropriate patient selection and low risk of fetal demise with FAV are critical factors for obtaining a survival benefit.

Assessment of the Melody valve in the mitral position in young children by echocardiography.

OBJECTIVES: Mitral valve replacement (MVR) in young children is limited by the lack of small prostheses. Our institution began performing MVR with modified, surgically placed, stented jugular vein grafts (Melody valve) in 2010. We sought to describe key echocardiographic features for pre- and postoperative assessment of this novel form of MVR. METHODS: The pre- and postoperative echocardiograms of 24 patients who underwent Melody MVR were reviewed. In addition to standard measurements, preoperative potential measurements of the mitral annulus were performed whereby dimensions were estimated for Melody sizing. A ratio of the narrowest subaortic region in systole to the actual mitral valve dimension (SubA:MV) was assessed for risk of postoperative left ventricular outflow tract obstruction (LVOTO). RESULTS: Melody MVR was performed at a median of 8.5 months (5.6 kg) for stenosis (5), regurgitation (3), and mixed disease (16). Preoperatively, actual mitral z scores measured hypoplastic (median -3.1 for the lateral [lat] dimension; -2.1 for the anteroposterior [AP] dimension). The potential measurements often had normal z scores with fair correlation with intraoperative Melody dilation (ρ = 0.51 and 0.50 for lat and AP dimensions, respectively, both P = .01). A preoperative SubA:MV <0.5 was associated with postoperative LVOTO, which occurred in 4 patients. Postoperatively, mitral gradients substantially improved, with low values relative to the effective orifice area of the Melody valve. No patients had significant regurgitation or perivalvar leak. CONCLUSIONS: Preoperative echocardiographic measurements may help guide intraoperative sizing for Melody MVR and identify patients at risk for postoperative LVOTO. Acute postoperative hemodynamic results were favorable; however, ongoing assessment is warranted.

Assessment of Progressive Pathophysiology After Early Prenatal Diagnosis of the Ebstein Anomaly or Tricuspid Valve Dysplasia.

In fetuses with Ebstein anomaly or tricuspid valve dysplasia (EA/TVD), poor hemodynamic status is associated with worse neonatal outcome. It is not known whether EA/TVD fetuses with more favorable physiology earlier in gestation progress to more severe disease in the third trimester. We evaluated if echocardiographic indexes in EA/TVD fetuses presenting <24 weeks of gestation are reliable indicators of physiologic status later in pregnancy. This multicenter, retrospective study included 51 fetuses presenting at <24 weeks of gestation with EA/TVD and serial fetal echocardiograms ≥4 weeks apart. We designated the following as markers of poor outcome: absence of anterograde flow across the pulmonary valve, pulmonary valve regurgitation, cardiothoracic area ratio >0.48, left ventricular (LV) dysfunction, or tricuspid valve (TV) annulus Z-score >5.6. Median gestational age at diagnosis was 21 weeks (range, 18 to 24). Eighteen fetuses (35%) had no markers for poor hemodynamic status initially, whereas only 7 of these continued to have no markers of poor outcome in the third trimester. Nine of 27 fetuses (33%) with anterograde pulmonary blood flow on the first echocardiogram developed pulmonary atresia; 7 of 39 (18%) developed new pulmonary valve regurgitation. LV dysfunction was present in 2 (4%) patients at <24 weeks but in 14 (37%) later (p <0.001). The TV annulus Z-score and cardiothoracic area both increased from diagnosis to follow-up. In conclusion, progressive hemodynamic compromise was common in this cohort. Our study highlights that care must be taken in counseling before 24 weeks, as the absence of factors associated with poor outcome early in pregnancy may be falsely reassuring.

Assessment of left ventricular endocardial fibroelastosis in fetuses with aortic stenosis and evolving hypoplastic left heart syndrome.

Systematic evaluation of left ventricular (LV) endocardial fibroelastosis (EFE) in the fetus has not been reported. The role of EFE in the pre- and postnatal evolution of hypoplastic left heart disease, and the implications of EFE for outcomes after prenatal intervention for fetal aortic stenosis with evolving hypoplastic left heart syndrome have also not been determined. A 4-point grading system (0-3) was devised for the assessment of fetal LV echogenicity, which was presumed to be due to EFE. Two reviewers independently graded EFE on the preintervention echocardiograms of fetuses treated with in utero aortic valvuloplasty for evolving hypoplastic left heart syndrome from 2000 to 2008. Intra- and interobserver reproducibility was determined for the EFE grade and characterization of related echocardiographic features. The relations among EFE severity, other left heart anatomic and physiologic variables, and postintervention outcomes were analyzed. The assessment and grading of EFE was possible for both observers in all 74 fetuses studied. By consensus, the EFE severity was grade 1 in 31 patients, grade 2 in 32, and grade 3 in 11. Fetuses with mild (grade 1) EFE had significantly greater maximum instantaneous aortic stenosis gradients (e.g., higher LV pressures) and less globular LV geometry than patients with grade 2 or 3 EFE on preintervention echocardiogram. The severity of EFE was not associated with the size of the aortic valve or LV. From preintervention to late gestation, the time-indexed change in LV end-diastolic volume was significantly greater in fetuses with grade 1 EFE than those with more severe EFE. Incorporation of EFE severity into our previously published threshold score improved the sensitivity and positive predictive value for the postnatal biventricular outcomes. In conclusion, echocardiographic grading of EFE is possible, with reasonable intra- and interobserver reliability in midgestation fetuses with evolving hypoplastic left heart syndrome. EFE severity corresponded to some indexes of left heart size, geometry, and function and with the probability of a biventricular outcome postnatally. Additional experience and external validation of the EFE grading scoring system are necessary.

Validation of 3D echocardiographic assessment of left ventricular volumes, mass, and ejection fraction in neonates and infants with congenital heart disease: a comparison study with cardiac MRI.

BACKGROUND: quantitative assessment and validation of left ventricular (LV) volumes and mass in neonates and infants with complex congenital heart disease (CHD) is important for clinical management but has not been undertaken. We compared matrix-array 3D echocardiography (3D echo) measurements of volumes, mass, and ejection fraction (EF) with those measured by cardiac MRI in young patients with CHD and small LVs because of either young age or LV hypoplasia. METHODS AND RESULTS: thirty-five patients aged <4 years (median, 0.8 years) undergoing MRI were prospectively enrolled. Three-dimensional echo was acquired immediately after MRI, and volume, mass, and EF measurements, using summation of discs methodology, were compared with MRI. Three-dimensional echo end-diastolic volume (24.4±15.7 versus 24.8±46.4 mL; P=0.01; intraclass correlation coefficient [ICC], 0.96) and end-systolic volume (12.3±8.6 versus 9.6±6.8 mL; P<0.001; ICC, 0.90) correlated with MRI with small mean differences (-0.49 mL [P=0.6] and 2.7 mL [P=0.001], respectively). Three-dimensional echo EF was smaller than MRI by 9.3% (P<0.001), and 3D echo LV mass measurements were comparable to MRI (17.3±10.3 versus 17.6±12 g; P<0.77; ICC, 0.93), with a small mean difference (1.1 g; P=0.28). There was good intra- and interobserver reliability for all measurements. CONCLUSIONS: in neonates and infants with CHD and small LVs (age appropriate or hypoplastic), matrix-array 3D echo measurements of mass and volumes compare well with MRI, providing an important modality for ventricular size and performance analysis in these patients, particularly in those with left-side heart obstructive lesions.

Association of socioeconomic position and medical insurance with fetal diagnosis of critical congenital heart disease.

BACKGROUND: Access to beneficial novel healthcare technology has been inequitable in the United States. Fetal echocardiography, used with increasing frequency for prenatal diagnosis (PD) of congenital heart disease, allows for optimal neonatal management and possible improved outcomes. We sought to evaluate whether PD of critical congenital heart disease is related to socioeconomic (SE) position, medical insurance, and race. METHODS AND RESULTS: In a retrospective review of infants with critical congenital heart disease who underwent surgical or catheter intervention at age <30 days in our institution during 2003 to 2006, we extracted 6 SE variables for the block groups of patient residence from 2000 US Census and calculated a previously validated composite SE score for each patient. PD occurred in 222 (50%) infants. Race was not significantly associated with PD. Private insurance patients were much more likely to have PD (odds ratio, 3.7 versus public insurance; 95% CI, 2.4 to 5.7; P<0.001), as were patients of higher SE position (PD, 62% in highest quartile versus 35% in lowest quartile; P=0.001). Odds of PD increased with increasing SE score (odds ratio, 1.7, 2.3, and 2.9 for each quartile of higher SE score versus those in lowest SE quartile; P<0.001). Patients from economically poor neighborhoods were less likely to have PD (odds ratio, 1.2 for each 10% increase in prevalence of poverty; P=0.04). Private medical insurance (odds ratio, 3.4; 95% CI, 2.1 to 5.5; P<0.001) was the strongest predictor of PD in the logistic regression model. CONCLUSIONS: Patients with public insurance and lower SE position are less likely to have a PD of critical congenital heart disease.

Matrix-array 3-dimensional echocardiographic assessment of volumes, mass, and ejection fraction in young pediatric patients with a functional single ventricle: a comparison study with cardiac magnetic resonance.

BACKGROUND: Quantitative assessment of ventricular volumes and mass in pediatric patients with single-ventricle physiology would aid clinical management, but it is difficult to obtain with 2-dimensional echocardiography. The purpose of the present study was to compare matrix-array 3-dimensional echocardiography (3DE) measurements of single-ventricle volumes, mass, and ejection fraction with those measured by cardiac magnetic resonance (CMR) in young patients. METHODS AND RESULTS: Twenty-nine patients (median age, 7 months) with a functional single ventricle undergoing CMR under general anesthesia were prospectively enrolled. The 3DE images were acquired at the conclusion of the CMR. Twenty-seven of 29 3DE data sets (93%) were optimal for 3DE assessment. Two blinded and independent observers performed 3DE measurements of volume, mass, and ejection fraction. The 3DE end-diastolic volume correlated well (r=0.96) but was smaller than CMR by 9% (P<0.01), and 3DE ejection fraction was smaller than CMR by 11% (P<0.01). There was no significant difference in measurements of end-systolic volume and mass. The 3DE interobserver differences for mass and volumes were not significant except for ejection fraction (8% difference; P<0.05). Intraobserver differences were not significant. CONCLUSIONS: In young pediatric patients with a functional single ventricle, matrix-array 3DE measurements of mass and volumes compare well with those obtained by CMR. 3DE will provide an important modality for the serial analysis of ventricular size and performance in young patients with functional single ventricles.