Delayed cortical development in fetuses with complex congenital heart disease

Neurologic impairment is a major complication of complex congenital heart disease (CHD). A growing body of evidence suggests that neurologic dysfunction may be present in a significant proportion of this high-risk population in the early newborn period prior to surgical interventions. We recently provided the first evidence that brain growth impairment in fetuses with complex CHD has its origins in utero. Here, we extend these observations by characterizing global and regional brain development in fetuses with hypoplastic left heart syndrome (HLHS), one of the most severe forms of CHD. Using advanced magnetic resonance imaging techniques, we compared in vivo brain growth in 18 fetuses with HLHS and 30 control fetuses from 25.4-37.0 weeks of gestation. Our findings demonstrate a progressive third trimester fall-off in cortical gray and white matter volumes (P < 0.001), and subcortical gray matter (P < 0.05) in fetuses with HLHS. Significant delays in cortical gyrification were also evident in HLHS fetuses (P < 0.001). In the HLHS fetus, local cortical folding delays were detected as early as 25 weeks in the frontal, parietal, calcarine, temporal, and collateral regions and appear to precede volumetric brain growth disturbances, which may be an early marker of elevated risk for third trimester brain growth failure.

Dilation of the ascending aorta after balloon valvuloplasty for aortic stenosis during infancy and childhood

Dilation of the ascending aorta (AA) is common in patients with a bicuspid aortic valve. The natural history of the aortic root and AA and the risk factors for dilation have not been characterized in patients with congenital aortic stenosis (AS) treated with balloon valvuloplasty during childhood. The present study was performed to determine the prevalence of aortic dilation in patients with congenital AS before and up to 20 years after balloon valvuloplasty performed during childhood. In patients who underwent balloon valvuloplasty for AS at age ≤ 18 years from 1984 to 2005, the aortic diameter measurements before intervention and at 5-year intervals afterward were recorded and the Z scores calculated. Among 156 patients (median age 1.5 years at valvuloplasty), the AA Z scores were significantly larger than normal before intervention (median Z score 1.5) and at all follow-up points (all p <0.001). Using mixed modeling, with time as a categorical variable (before intervention, 5-year window, 10-year window, and so forth), the mean AA Z score was greater at all postvalvuloplasty points than before the intervention, with mean Z score increases of 1.20 at 5 years and 2.11 at 20 years (p <0.001). Moderate or greater aortic regurgitation early after valvuloplasty was associated with greater AA Z scores than mild or less aortic regurgitation, with a progressive difference over time. More significant residual AS after valvuloplasty was associated with lower AA Z scores over time. In conclusion, AA dilation is common in children with congenital AS and continues to progress over many years after balloon valvuloplasty.

Clinical and stent-related outcomes after transcatheter or operative placement of bare-metal stents in the ventricular septum or subvalvar systemic outflow tract

BACKGROUND

Stenting of the systemic ventricular outflow tract and creation or enlargement of a ventricular septal defect using stents are potential therapeutic options in rare patients with congenital heart disease who develop significant ventricular hypertension due to outflow obstruction. These stents may be at increased risk of fracture because of exposure to cyclic compressive stresses. The objective of this study was to evaluate the safety and efficacy of this intervention and to determine the incidence of stent fracture and other adverse outcomes after placement of intraventricular or interventricular stents for this indication.

METHODS AND RESULTS

Between 1992 and 2010, 27 patients underwent bare-metal stent placement in the ventricular septum or subvalvar systemic outflow tract, using 1 of the following 3 delivery approaches: (1) percutaneous (n=18), (2) intraoperative (n=8), and (3) hybrid (n=1). The median ventricular-to-aortic systolic pressure ratio decreased from 1.7 (1.3-2.6) to 1.1 (0.9-1.8) (P<0.001). Survival free from surgical reintervention for outflow obstruction was 92% at 1 year and 66% at 3 years. Stent fracture was diagnosed in 11 patients (41%) a median of 2.6 years (0.03-7.8 years) after stent placement and was always associated with recurrent obstruction. Survival free from diagnosis of stent fracture was 84% at 1 year and 73% at 3 years. Other adverse events included complete heart block (n=2) and increased atrioventricular valve regurgitation requiring surgical intervention (n=2).

CONCLUSIONS

Transcatheter, intraoperative, or hybrid stenting of the ventricular septum or systemic outflow tract is feasible and effective in the short term. Stent fractures were common during follow-up and associated with recurrent obstruction.

Left ventricular function and geometry in fetuses with severe tricuspid regurgitation

OBJECTIVE

Neonatal congenital tricuspid valve (TV) dysplasia and/or displacement (Ebstein's malformation) with severe tricuspid regurgitation (TR) is a challenging condition in which outcomes are frequently poor. Little is known about left ventricular (LV) function during the perinatal period in patients with congenital TV disease. The objective of this study was to evaluate LV function in fetuses with congenital TV anomalies associated with significant TR.

METHODS

Serial fetal echocardiograms in 16 fetuses with congenital TV dysplasia and/or displacement (five neonatal survivors and 11 fetal or neonatal deaths) were reviewed. LV stroke volume, LV end-diastolic volume (LVEDV), LV end-diastolic dimension (LVIDd), the LV eccentricity index, thoracic and cardiac areas and the cardiothoracic area ratio (CTAR), the right atrium area index, and LV longitudinal strains were compared according to gestational age and clinical outcome.

RESULTS

The gestational age-adjusted LVEDV (Z-score) was lower in late gestation (-1.2 ± 1.2 at last examination ≥ 28 weeks) than earlier in gestation (0.3 ± 1.5 at last examination < 28 weeks) and LV output was lower than reported late-gestation normal values. LV short-axis dimension correlated with LV volume and CTAR. LV mid-septal strain was lower than the normal average of fetal mid-septal strain and correlated with the LV eccentricity index. Among these parameters, only the LV eccentricity index differed between survivors and non-survivors.

CONCLUSION

LV function and anatomy are abnormal in fetuses with severe congenital TV anomalies and may be important contributors to outcome.

Left ventricular remodeling and improvement in diastolic function after balloon aortic valvuloplasty for congenital aortic stenosis

BACKGROUND

In congenital aortic stenosis, chronic pressure load has detrimental effects on left ventricular (LV) systolic and diastolic function. Reduction in LV pressure load with balloon aortic valvuloplasty (BAVP) may improve diastolic function.

METHODS AND RESULTS

Echocardiographic and catheterization data for 25 consecutive patients undergoing BAVP for congenital aortic stenosis were retrospectively analyzed. Median age at BAVP was 11.5 years (3.2-40.1). LV end-diastolic pressure was elevated (≥15 mm Hg) in 72% of patients, with a median of 17 mm Hg (range, 9-24). With BAVP, median aortic stenosis gradient was reduced from 63 mm Hg (range, 44-105) to 30 mm Hg (range, 10-43). Aortic regurgitation increased from trivial (none to mild) to mild (trivial to moderate). Pre-BAVP early diastolic mitral inflow velocity/tissue Doppler early diastolic velocity (E/E´) correlated with LV end-diastolic pressure (r=0.52, P=0.007). On follow-up echocardiography (median, 11 months after BAVP), aortic stenosis gradient was lower (P<0.001) and degree of AR was higher (P=0.01) compared with pre-BAVP echocardiograms. LV end-diastolic volume z-score increased (P=0.02), LV mass was unchanged, and LV mass:volume decreased (P=0.002). Mitral annular and septal E´ (P<0.001) were higher and E/E´ was lower after dilation (10.8 versus 14.2, P<0.001). Lower pre-BAVP E/E´ and lower pre-BAVP LV mass z-score were associated with lower post-BAVP E/E.

CONCLUSION

After BAVP, LV remodeling characterized by an increase in EDV and decrease in LV mass:volume occurs and echocardiographic measures of diastolic function and LV end-diastolic pressure improve in most patients. Risk factors for persistent diastolic dysfunction include higher pre-BAVP LV mass z-score and worse pre-BAVP diastolic function.

Relation of systemic-to-pulmonary artery collateral flow in single ventricle physiology to palliative stage and clinical status

Systemic-to-pulmonary collateral arteries (SPCs) are common in patients with single-ventricle physiology, but their impact on clinical outcomes is unclear. The aim of this study was to use retrospective cardiac magnetic resonance data to determine the relation between SPC flow and palliative stage and clinical status in single-ventricle physiology. Of 116 patients, 78 were after Fontan operation (median age 19 years) and 38 were at an earlier palliative stage (median age 2 years). SPC flow was quantified as aortic flow minus total caval flow or total pulmonary vein flow minus total branch pulmonary artery flow. Median SPC flow/body surface area (BSA) was higher in the pre-Fontan group (1.06 vs 0.43 L/min/m(2), p <0.0001) and decreased nonlinearly with increasing age after the Fontan operation (r(2) = 0.17, p <0.0001). In the Fontan group, patients in the highest quartile of SPC flow had larger ventricular end-diastolic volume/BSA (p <0.0001) and were older at the time of Fontan surgery (p = 0.04), but SPC flow/BSA was not associated with heart failure symptoms, atrial or ventricular arrhythmias, atrioventricular valve regurgitation, the ventricular ejection fraction, or peak oxygen consumption. In multivariate analysis of all patients (n = 116), higher SPC flow was independently associated with pre-Fontan status, unilateral branch pulmonary artery stenosis, a diagnosis of hypoplastic left-heart syndrome, and previous catheter occlusion of SPCs (model r(2) = 0.37, p <0.0001). In conclusion, in this cross-sectional study of single-ventricle patients, BSA-adjusted SPC flow was highest in pre-Fontan patients and decreased after the Fontan operation with minimal clinical correlates aside from ventricular dilation.

Outcome after repair of cor triatriatum

Cor triatriatum represents <0.1% of all congenital cardiac malformations. Symptoms in patients with cor triatriatum are related to pulmonary venous obstruction and pressure loading of the right side of the heart. The aim of this study was to describe our institutional experience with repair of cor triatriatum. From June 1963 to June 2010, 65 patients underwent repair at a median age of 7.2 months (range 2 days to 47.6 years). Among these patients, 49 (75%) had associated congenital heart defects. Atrial septal defect (n = 29), ventricular septal defect (n = 15), partially or totally anomalous pulmonary venous return (n = 14), mitral valve abnormalities (n = 11), and supravalvar mitral ring (n = 5) were the most common associated defects. Surgical treatment consisted of excision of the membrane, along with additional procedures in 47 patients (72%). Five patients had new postoperative supraventricular arrhythmias. During a median follow-up period of 5.4 years, no patients underwent reintervention for recurrent left atrial obstruction, 7 patients were noted to have minor residual cor triatriatum without obstruction, and 8 patients (including 4 diagnosed before cor triatriatum repair) had pulmonary vein stenosis, 6 of whom underwent intervention for that reason. In conclusion, in this large surgical series of patients who underwent repair of cor triatriatum, there were no cases of significant residual or recurrent cor triatriatum. Although the association between cor triatriatum and pulmonary vein stenosis has been described previously, the relative frequency of this condition in our cohort (>10%, including patients diagnosed before and after cor triatriatum repair) is noteworthy. Abnormalities of the mitral valve and a supravalvar mitral ring were also seen more often than the existing research would suggest, which may be another important consideration in evaluating and following these patients.

Cardiopulmonary exercise function among patients undergoing transcatheter pulmonary valve implantation in the US Melody valve investigational trial

OBJECTIVES

We assessed the hypothesis that there is an improvement in clinical and physiologic parameters of cardiopulmonary exercise testing (CPET) after implantation of a transcatheter pulmonary valve (TPV).

BACKGROUND

Transcatheter pulmonary valve provides a new tool for treating conduit stenosis and regurgitation in patients with right ventricle (RV) to pulmonary artery conduit dysfunction.

METHODS

Patients who underwent a TPV placement between January 2007 and January 2010 (N = 150) were investigated with a standardized CPET protocol before and at 6 months after TPV placement. Cardiopulmonary exercise testing was performed on a mechanically braked cycle ergometer with respiratory gas exchange analysis.

RESULTS

Six months post TPV, small but statistically significant improvements were observed in the maximum workload (65.0% ± 18.8% to 68.3% ± 20.3% predicted, P < .001) and the ratio of minute ventilation to CO(2) production at the anaerobic threshold (30.8 ± 4.7 to 29.1 ± 4.1, P < .001). There was no significant change in peak oxygen consumption (VO(2)). Patients with pre-TPV hemodynamics consistent with RV dysfunction and patients with a lower pre-TPV peak VO(2) tended to have the greatest improvement in peak VO(2). The correlation between TPV-related improvements in peak VO(2) and baseline clinical variables were weak, however, and these variables could not be used to reliably identify patients likely to have improved peak VO(2) after TPV.

CONCLUSION

In patients with RV to pulmonary artery conduit dysfunction, TPV is associated with modest improvement in exercise capacity and gas exchange efficiency during exercise.

Catheterization for Congenital Heart Disease Adjustment for Risk Method (CHARM)

OBJECTIVES

This study sought to develop a method to adjust for case mix complexity in catheterization for congenital heart disease to allow equitable comparisons of adverse event (AE) rates.

BACKGROUND

The C3PO (Congenital Cardiac Catheterization Project on Outcomes) has been prospectively collecting data using a Web-based data entry tool on all catheterization cases at 8 pediatric institutions since 2007.

METHODS

A multivariable logistic regression model with high-severity AE outcome was built using a random sample of 75% of cases in the multicenter cohort; the models were assessed in the remaining 25%. Model discrimination was assessed by the C-statistic and calibration with Hosmer-Lemeshow test. The final models were used to calculate standardized AE ratios.

RESULTS

Between August 2007 and December 2009, 9,362 cases were recorded at 8 pediatric institutions of which high-severity events occurred in 454 cases (5%). Assessment of empirical data yielded 4 independent indicators of hemodynamic vulnerability. Final multivariable models included procedure type risk category (odds ratios [OR] for category: 2 = 2.4, 3 = 4.9, 4 = 7.6, all p < 0.001), number of hemodynamic indicators (OR for 1 indicator = 1.5, ≥2 = 1.8, p = 0.005 and p < 0.001), and age <1 year (OR: 1.3, p = 0.04), C-statistic 0.737, and Hosmer-Lemeshow test p = 0.74. Models performed well in the validation dataset, C-statistic 0.734. Institutional event rates ranged from 1.91% to 7.37% and standardized AE ratios ranged from 0.61 to 1.41.

CONCLUSIONS

Using CHARM (Catheterization for Congenital Heart Disease Adjustment for Risk Method) to adjust for case mix complexity should allow comparisons of AE among institutions performing catheterization for congenital heart disease.

Characterization of radiation exposure and effect of a radiation monitoring policy in a large volume pediatric cardiac catheterization lab

OBJECTIVES

This study aimed to characterize radiation dose during cardiac catheterization in congenital heart disease and to assess changes in dose after the introduction of a radiation monitoring policy.

BACKGROUND

Minimizing radiation exposure is an important patient safety initiative and relatively few data are available characterizing radiation dose for the broad spectrum of congenital cardiac catheter-based interventions.

METHODS

Radiation dose data were reviewed on all cases since 7/1/05 at a single large center. Procedures were classified according to 20 common case types then subdivided into five age categories. Groups with <20 cases were excluded. Radiation dose was estimated by cumulative air KERMA (mGy) and DAP (dose area product, μGym(2)) which were reported as median and interquartile range (IQR). We also examined differences in radiation dose before and after the implementation of a radiation policy.

RESULTS

Between 7/1/05 and 12/10/08, 3,365 cases were identified for inclusion. Radiation dose increased with age and procedural complexity. Patients were characterized into low, medium, and high dose categories relative to each other. "Low" dose cases included isolated pulmonary or aortic valvotomy, pre-Fontan assessment, and ASD closure. "High" dose cases involved multiple procedures in pulmonary arteries or veins. After introduction of a radiation policy, there was a significant decrease in radiation dose across a variety of case types, particularly among infants and young children.

CONCLUSIONS

Radiation dose in congenital cardiac catheterization varies by age and procedure type. A radiation monitoring and notification policy may have contributed to reduced radiation dose.

Stent Fracture, Valve Dysfunction, and Right Ventricular Outflow Tract Reintervention After Transcatheter Pulmonary Valve Implantation

Background—

Among patients undergoing transcatheter pulmonary valve (TPV) replacement with the Melody valve, risk factors for Melody stent fracture (MSF) and right ventricular outflow tract (RVOT) reintervention have not been well defined.

Methods and Results—

From January 2007 to January 2010, 150 patients (median age, 19 years) underwent TPV implantation in the Melody valve Investigational Device Exemption trial. Existing conduit stents from a prior catheterization were present in 37 patients (25%, fractured in 12); 1 or more new prestents were placed at the TPV implant catheterization in 51 patients. During follow-up (median, 30 months), MSF was diagnosed in 39 patients. Freedom from a diagnosis of MSF was 77±4% at 14 months (after the 1-year evaluation window) and 60±9% at 39 months (3-year window). On multivariable analysis, implant within an existing stent, new prestent, or bioprosthetic valve (combined variable) was associated with longer freedom from MSF ( P <0.001), whereas TPV compression ( P =0.01) and apposition to the anterior chest wall ( P =0.02) were associated with shorter freedom from MSF. Freedom from RVOT reintervention was 86±4% at 27 months. Among patients with a MSF, freedom from RVOT reintervention after MSF diagnosis was 49±10% at 2 years. Factors associated with reintervention were similar to those for MSF.

Conclusions—

MSF was common after TPV implant in this multicenter experience and was more likely in patients with severely obstructed RVOT conduits and when the TPV was directly behind the anterior chest wall and/or clearly compressed. A TPV implant site protected by a prestent or bioprosthetic valve was associated with lower risk of MSF and reintervention.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00740870.

Short-Term Performance of the Transcatheter Melody Valve in High-Pressure Hemodynamic Environments in the Pulmonary and Systemic Circulations

Background—

The Melody valve is approved for percutaneous pulmonary valve replacement in dysfunctional right ventricular outflow tracts. The function of this valve when subjected to high-pressure loads in humans is unknown. The aim of this study was to describe the immediate and short-term results of Melody valves implanted in a high-pressure environment.

Methods and Results—

Definitions of a high-pressure system were established for Melody valves implanted in the systemic (ie, aortic or mitral position) and pulmonary (ie, right ventricular outflow tract conduit or tricuspid valve annulus) circulations. Implants in these environments were ascertained from databases of the 5 centers that participated in the US Investigational Device Exemption trial. Thirty implants met the inclusion criteria: 23 pulmonary circulation implants (all in the pulmonary position) systemic circulation implants (5 in the native aortic position, 1 in a left ventricle-to-descending aorta conduit, and 1 in the mitral annulus). All pulmonary circulation implants were performed percutaneously in the catheterization laboratory. A hybrid approach (surgical exposure for transcatheter implant) was used for 4 of the aortic implants. There were no procedure-related deaths. Three patients died of nonprocedure- and nonvalve-related causes. At 1 year, freedom from moderate to severe regurgitation was 100%, and freedom from mild regurgitation was 90%. Freedom from moderate to severe stenosis was 86% at 1 year.

Conclusions—

Short-term performance of the Melody valve in high-pressure environments is encouraging, with good valve function in all patients.

Factors associated with subsequent arch reintervention after initial balloon aortoplasty in patients with Norwood procedure and arch obstruction

OBJECTIVES

The aim of this study was to determine whether there are identifiable factors associated with increased risk for aortic arch reintervention in patients who have undergone balloon aortoplasty (BD) for aortic arch obstruction (COA) after the Norwood procedure (NP).

BACKGROUND

BD has been shown to be an effective acute therapy for COA after the NP. However, recurrent obstruction requiring repeat intervention is not uncommon.

METHODS

All patients who underwent BD as the initial intervention for COA after the NP from to January 1993 to May 2009 were retrospectively analyzed (n = 116).

RESULTS

The median age at initial BD was 4.5 months. The median follow-up period was 3.4 years. Procedures were considered acutely successful in 92% of patients, with a median gradient reduction overall from 24 to 3 mm Hg (p < 0.0001) and a COA diameter increase of 52% (p < 0.0001). By Kaplan-Meier analysis, freedom from reintervention was 69% at 1 year and 58% at 5 years, and freedom from reoperation was 82% at 1 year and 79% at 5 years. By Cox regression analysis, proximal arch obstruction, age <3 months at BD, moderate or greater ventricular dysfunction, moderate or greater atrioventricular valve regurgitation on pre-catheterization echocardiography, and higher post-BD coarctation gradient were associated with shorter freedom from reoperation.

CONCLUSIONS

Despite a high acute success rate, a significant proportion of patients treated with BD for post-NP COA underwent reintervention during follow-up. The risk for arch reintervention is highest in patients with proximal arch obstruction, those age <3 months at the time of BD, and those with less successful acute results.

Circumferential and longitudinal ventricular strain in the normal human fetus

BACKGROUND

Echocardiography with speckle tracking is a novel, angle-independent technique for assessing global and regional cardiac function. Normal data on longitudinal strain have been reported for human fetuses. The aim of this study was to define circumferential left ventricular (LV) strain in a normal fetal population.

METHODS

Singleton fetuses between 17 and 42 weeks in gestational age with no adverse maternal health issues or fetal abnormalities were studied. Regional and averaged cardiac strain were measured using syngo Velocity Vector Imaging software.

RESULTS

Data from 81 fetuses were analyzed (mean gestational age, 29.2 ± 5.7 weeks). Overall, average midventricular circumferential strain was 18.7 ± 3.3%, LV longitudinal strain was 15.2 ± 2.7%, and right ventricular longitudinal strain was 16.0 ± 3.3%, with no correlation with gestational age.

CONCLUSION

This is the first study to report normal fetal LV circumferential strain. These data may be useful as a reference for assessing fetal cardiac function. The retrospective study design and relatively low frame rates used in this study were important limitations.

The impact of pulmonary venous hypertension on the pulmonary circulation in the young

OBJECTIVE AND DESIGN

Pulmonary venous hypertension is a well-characterized cause of pulmonary hypertension in adults, but little is known regarding the relationship between left atrial pressure and pulmonary arteriolar resistance in the young. Also, in adults relief of pulmonary venous hypertension results in a marked fall in pulmonary arteriolar resistance, but this could be different in children because vascular changes are more severe in young patients than adults with mitral stenosis. We inspected records of children at Children's Hospital Boston having mitral balloon valvuloplasty, and patients ≤5 years old having mitral valve replacement, to determine (1) the relationship between left atrial pressure and pulmonary arterial pressure and resistance (n = 94 children, median age 17.8 months) and (2) how pulmonary arteriolar resistance changes after mitral valve replacement.

RESULTS

The average indexed pulmonary arteriolar resistance was 7.8 ± 5.9 units and was unrelated to age but was positively related to left atrial pressure. There was great variability in pulmonary arteriolar resistance for any given left atrial pressure. Pulmonary arterial pressure (n = 16) and pulmonary arterial resistance (n = 9) were measured before and after mitral valve replacement (median = 29.4 months old). Despite preoperative indexed pulmonary arterial resistance of ≥5 units in 11 of 15 patients, postoperative pulmonary arterial pressure was substantially lower in all save three, and two patients with high pulmonary arterial pressure still had high left atrial pressure postoperatively (25 mmHg).

CONCLUSIONS

We conclude that in young children, as in adults, pulmonary arterial resistance generally falls greatly with reduction in left atrial pressure.

Percutaneous tricuspid valve replacement in congenital and acquired heart disease

OBJECTIVES

This study sought to describe the first human series of percutaneous tricuspid valve replacements in patients with congenital or acquired tricuspid valve (TV) disease.

BACKGROUND

Percutaneous transcatheter heart valve replacement of the ventriculoarterial (aortic, pulmonary) valves is established. Although there are isolated reports of transcatheter atrioventricular heart valve replacement (hybrid and percutaneous), this procedure has been less frequently described; we are aware of no series describing this procedure for TV disease.

METHODS

We approached institutions with significant experience with the Melody percutaneous pulmonary valve (Medtronic, Inc., Minneapolis, Minnesota) to collect data where this valve had been implanted in the tricuspid position. Clinical and procedural data were gathered for 15 patients. Indications for intervention included severe hemodynamic compromise and perceived high surgical risk; all had prior TV surgery and significant stenosis and/or regurgitation of a bioprosthetic TV or a right atrium-to-right ventricle conduit.

RESULTS

Procedural success was achieved in all 15 patients. In patients with predominantly stenosis, mean tricuspid gradient was reduced from 12.9 to 3.9 mm Hg (p < 0.01). In all patients, tricuspid regurgitation was reduced to mild or none. New York Heart Association functional class improved in 12 patients. The only major procedural complication was of third-degree heart block requiring pacemaker insertion in 1 patient. One patient developed endocarditis 2 months after implant, and 1 patient with pre-procedural multiorgan failure did not improve and died 20 days after the procedure. The remaining patients have well-functioning Melody valves in the TV position a median of 4 months after implantation.

CONCLUSIONS

In selected cases, patients with prior TV surgery may be candidates for percutaneous TV replacement.

Echocardiographic Evaluation Before Bidirectional Glenn Operation in Functional Single-Ventricle Heart Disease

Background—

Cardiac catheterization is routinely performed in patients with single ventricle before bidirectional Glenn operation (BDG). There is interest in noninvasive evaluation alone before BDG, but concern for echocardiography successfully imaging the relevant anatomy persists. We evaluated the accuracy of echocardiographic imaging of vascular anatomy.

Methods and Results—

Diagnostic images of 130 patients who had echocardiography and catheterization before BDG were reviewed; diameters of the pulmonary arteries (PAs) and aortic arch were measured, and stenoses were recorded. Patient and procedural factors associated with echocardiographic imaging were analyzed. Median age at echocardiography was 4 months; the most common diagnosis was hypoplastic left heart syndrome (55%). The left PA was imaged by echocardiography in 83 patients (64%), with 4 of 21 stenoses (19%) diagnosed by catheterization identified; similarly, the right PA was imaged in 81 (62%), and 3 of 17 stenoses (18%) were identified. The distal aortic arch was visualized in 104 (80%), with successful identification of 21 of 27 (78%) of coarctations diagnosed by catheterization. Complete vascular echocardiography (visualization of PAs and aortic arch) occurred in 43% and was not obtained more frequently with sedation.

Conclusions—

In a large cohort of patients presenting for BDG, evaluation by echocardiography frequently failed to image the PAs and missed the majority of PA stenoses. Sedation did not appear to improve the performance of echocardiography for evaluation of the PAs. Echocardiography cannot be relied on as the sole investigation before BDG.

Postnatal left ventricular diastolic function after fetal aortic valvuloplasty

Fetal aortic balloon valvuloplasty (FAV) has shown promise in altering in utero progression of aortic stenosis to hypoplastic left heart syndrome. In patients who achieve a biventricular circulation after FAV, left ventricular (LV) compliance may be impaired. Echocardiographic indexes of diastolic function were compared between patients with biventricular circulation after FAV, congenital aortic stenosis (AS), and age-matched controls. In the neonatal period, patients with FAV had similar LV, aortic, and mitral valve dimensions but more evidence of endocardial fibroelastosis than patients with AS. Patients with FAV underwent more postnatal cardiac interventions than patients with AS (p = 0.007). Mitral annular early diastolic tissue velocity (E') was lower in patients with FAV and those with AS and controls in the neonatal period and over follow-up (p <0.001). Septal E' was similar among all 3 groups in the neonatal period. In follow-up patients, with FAV had lower septal E' than patients with AS or controls (p <0.001). Early mitral inflow velocity/E' was higher in patients with FAV as neonates and at follow-up (p <0.001). Mitral inflow pulse-wave Doppler-derived indexes of diastolic function were similar between groups. In conclusion, echocardiographic evidence of LV diastolic dysfunction is common in patients with biventricular circulation after FAV and persists in short-term follow-up. LV diastolic dysfunction in this unique population may have important implications on long-term risk of left atrial and subsequent pulmonary hypertension.

Early reintervention on the pulmonary arteries and right ventricular outflow tract after neonatal or early infant repair of truncus arteriosus using homograft conduits

Patients with truncus arteriosus often require pulmonary arterial (PA) and/or right ventricular outflow tract (RVOT) reintervention within the first year of repair. However, little is known about the risk factors for early reintervention on the PAs or RVOT in this population. The objective of the present retrospective cohort study was to determine the risk factors for early PA or RVOT reintervention after repair of truncus arteriosus in neonates and young infants. Of 156 patients ascertained (median age at repair 14 days; 143 early survivors), reinterventions on the RVOT and/or PAs were performed in 109. The first reintervention was catheter therapy in 73 patients (conduit dilation/stenting in 29, PA dilation/stenting in 31, both in 13) and conduit reoperation in 36 patients. The freedom from any RVOT or PA reintervention was 68 ± 4% at 1 year and 48 ± 5% at 2 years. The factors associated with early reintervention (shorter 1-year freedom from reintervention) on univariate analysis were repair quartile, neonatal repair, smaller weight at repair, and smaller implanted conduit size. On multivariable analysis, only smaller conduit size remained significant (multivariable hazard ratio 0.66/mm, range 0.53 to 0.83; p <0.001). The freedom from conduit reoperation was 92 ± 3% at 1 year and 76 ± 4% at 2 years. Overall, the left and right PA sizes were modestly larger than normal by the 1-sample t test, and PA Z scores and the PA area index were not associated with the risk of reintervention. Early reintervention for PA and/or RVOT conduit obstruction is common after neonatal and early infant repair of truncus arteriosus using homograft conduits. A smaller conduit size was associated with early RVOT/PA reintervention. The branch PA size was normal before surgery, suggesting that the PA stenosis in these patients resulted from factors other than intrinsic stenosis or hypoplasia.

Congenital portosystemic venous connections and other abdominal venous abnormalities in patients with polysplenia and functionally univentricular heart disease: a case series and literature review

OBJECTIVE

Published case reports suggest that congenital portosystemic venous connections (PSVC) and other abdominal venous anomalies may be relatively frequent and potentially important in patients with polysplenia syndrome. Our objective was to investigate the frequency and range of portal and other abdominal systemic venous anomalies in patients with polysplenia and inferior vena cava (IVC) interruption who underwent a cavopulmonary anastomosis procedure at our center, and to review the published literature on this topic and the potential clinical importance of such anomalies.

DESIGN

Retrospective cohort study and literature review were used.

RESULTS

Among 77 patients with heterotaxy, univentricular heart disease, and IVC interruption who underwent a bidirectional Glenn and/or modified Fontan procedure, pulmonary arteriovenous malformations were diagnosed in 33 (43%). Bilateral superior vena cavas were present in 42 patients (55%). Despite inadequate imaging in many patients, a partial PSVC, dual IVCs, and/or renal vein anomalies were detected in 15 patients (19%). A PSVC formed by a tortuous vessel running from the systemic venous system to the extrahepatic portal vein was found in six patients (8%). Abdominal venous anomalies other than PSVC were documented in 13 patients (16%), including nine (12%) with some form of duplicated IVC system, with a large azygous vein continuing to the superior vena cava and a parallel, contralateral IVC of similar or smaller size, and seven with renal vein anomalies. In patients with a partial PSVC or a duplicate IVC that connected to the atrium, the abnormal connection allowed right-to-left shunting.

CONCLUSIONS

PSVC and other abdominal venous anomalies may be clinically important but under-recognized in patients with IVC interruption and univentricular heart disease. In such patients, preoperative evaluation of the abdominal systemic venous system may be valuable. More data are necessary to determine whether there is a pathophysiologic connection between the polysplenia variant of heterotaxy, PSVC, and cavopulmonary anastomosis-associated pulmonary arteriovenous malformations.

Aortic valve reinterventions after balloon aortic valvuloplasty for congenital aortic stenosis intermediate and late follow-up

OBJECTIVES

the aim of this study was to evaluate the long-term results of transcatheter balloon aortic valvuloplasty, the preferred treatment for congenital aortic stenosis (AS).

BACKGROUND

aortic valve function and reintervention late after this procedure are not well characterized.

METHODS

from 1985 to 2008, 563 patients underwent balloon dilation for congenital AS. After excluding those converted to univentricular circulation and/or died ≤ 30 days after the procedure, 509 patients constituted the study cohort.

RESULTS

The median follow-up period was 9.3 years (range 0.1 to 23.6 years); cumulative follow-up was 5,003 patient-years. The median age was 2.4 years (range 1 day to 40.5 years), and most patients (73%) had isolated native AS. Peak AS gradients decreased significantly after dilation (median decrease, 35 mm Hg), and acute post-dilation aortic regurgitation was moderate or greater in 70 patients (14%). Older patients more often had post-dilation aortic regurgitation (p < 0.001). During follow-up, 225 patients (44%) underwent aortic valve reintervention: repeat balloon dilation in 115 (23%), aortic valve repair in 65 (13%), and aortic valve replacement in 116 (23%). Survival free from any aortic valve reintervention was 89 ± 1% at 1 year, 72 ± 2% at 5 years, 54 ± 3% at 10 years, and 27 ± 3% at 20 years. Freedom from aortic valve replacement was 90 ± 2% at 5 years, 79 ± 3% at 10 years, and 53 ± 4% at 20 years. In multivariate analyses, lower post-dilation AS gradient and lower grade of post-dilation aortic regurgitation were associated with longer freedom from aortic valve replacement, but age, era, and pre-dilation AS severity were not.

CONCLUSIONS

although transcatheter aortic valvuloplasty is effective for relief of congenital AS, there are steady long-term hazards for surgical aortic valve reintervention and replacement that are independent of age at initial intervention or AS severity.

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.

To close or not to close: the very small patent ductus arteriosus

Patent ductus arteriosus (PDA) accounts for approximately 10% of all congenital heart diseases, with an incidence of at least 2-4 per 1000 term births. Closure of the large, hemodynamically significant PDA is established as the standard of care, and can be performed safely and effectively using either surgical or transcatheter methods. The appropriate management of the very small, hemodynamically insignificant PDA is less clear. Routine closure of such defects has been advocated to eliminate or reduce the risk of infective endocarditis (IE). However, the risk of IE in patients with a small PDA appears to be extremely low, and IE is treatable. Although closure of the small PDA is generally safe and technically successful, it is unknown whether this treatment truly improves the risk:benefit balance compared with observation. In this article, we review the published literature on the natural history and treatment outcomes in individuals with a PDA, the epidemiology and outcomes of IE, particularly in association with PDA, and the rationale and evidence for closure of the very small PDA.

Pre-stenting with a bare metal stent before percutaneous pulmonary valve implantation: acute and 1-year outcomes

OBJECTIVES

To determine the feasibility and safety of pre-stenting with a bare metal stent (BMS) before percutaneous pulmonary valve implantation (PPVI), and to analyse whether this approach improves haemodynamic outcomes and impacts on the incidence of PPVI stent fractures.

DESIGN

Retrospective analysis of prospectively collected data.

SETTING

Tertiary paediatric and adult congenital heart cardiac centre.

PATIENTS AND INTERVENTIONS

108 consecutive patients with congenital heart disease underwent PPVI between September 2005 and June 2008 (54 with PPVI alone, 54 with BMS pre-stenting before PPVI).

RESULTS

There were no significant differences in procedural complication rates. Acutely, there was no difference in haemodynamic outcomes. Serial echocardiography revealed that in the subgroups of 'moderate' (26-40 mm Hg) and 'severe' (>40 mm Hg) right ventricular outflow tract (RVOT) obstruction, patients with pre-stenting showed a tendency towards lower peak RVOT velocities compared to patients after PPVI alone (p=0.01 and p=0.045, respectively). The incidence of PPVI stent fractures was not statistically different between treatment groups at 1 year (PPVI 31% vs BMS+PPVI 18%; p=0.16). However, pre-stenting with BMS was associated with a lower risk of developing PPVI stent fractures (HR 0.35, 95% CI 0.14 to 0.87, p=0.024). The probability of freedom from serious adverse follow-up events (death, device explantation, repeat PPVI) was not statistically different at 1 year (PPVI 92% vs BMS+PPVI 94%; p=0.44).

CONCLUSIONS

Pre-stenting with BMS before PPVI is a feasible and safe modification of the established implantation protocol. Pre-stenting is associated with a reduced risk of developing PPVI stent fractures.

Short- and medium-term outcomes after transcatheter pulmonary valve placement in the expanded multicenter US melody valve trial

BACKGROUND

Transcatheter pulmonary valve placement is an emerging therapy for pulmonary regurgitation and right ventricular outflow tract obstruction in selected patients. The Melody valve was recently approved in the United States for placement in dysfunctional right ventricular outflow tract conduits.

METHODS AND RESULTS

From January 2007 to August 2009, 136 patients (median age, 19 years) underwent catheterization for intended Melody valve implantation at 5 centers. Implantation was attempted in 124 patients; in the other 12, transcatheter pulmonary valve placement was not attempted because of the risk of coronary artery compression (n=6) or other clinical or protocol contraindications. There was 1 death from intracranial hemorrhage after coronary artery dissection, and 1 valve was explanted after conduit rupture. The median peak right ventricular outflow tract gradient was 37 mm Hg before implantation and 12 mm Hg immediately after implantation. Before implantation, pulmonary regurgitation was moderate or severe in 92 patients (81% with data); no patient had more than mild pulmonary regurgitation early after implantation or during follow-up (>or=1 year in 65 patients). Freedom from diagnosis of stent fracture was 77.8+/-4.3% at 14 months. Freedom from Melody valve dysfunction or reintervention was 93.5+/-2.4% at 1 year. A higher right ventricular outflow tract gradient at discharge (P=0.003) and younger age (P=0.01) were associated with shorter freedom from dysfunction.

CONCLUSIONS

In this updated report from the multicenter US Melody valve trial, we demonstrated an ongoing high rate of procedural success and encouraging short-term valve function. All reinterventions in this series were for right ventricular outflow tract obstruction, highlighting the importance of patient selection, adequate relief of obstruction, and measures to prevent and manage stent fracture. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00740870.

Fetal diagnosis of interrupted aortic arch

To determine the frequency of prenatal detection among liveborn patients with an interrupted aortic arch (IAA), the accuracy of prenatal diagnosis, and the anatomic features associated with IAA in the fetus. The prenatal diagnosis of an IAA is challenging. The data on the features and outcomes of fetal IAA are limited. This was a retrospective review of the fetuses and neonates diagnosed with IAA at the Children's Hospital Boston. From 1988 to 2009, 26 fetuses were diagnosed with an IAA. Of these, 21 were live born, and 5 pregnancies were terminated. Of these 21 patients, 18 were confirmed to have an IAA after birth and 3 had severe aortic coarctation. Of the 56 patients diagnosed with an IAA as neonates, 3 had a prenatal echocardiogram that did not include the correct diagnosis. Among the liveborn patients with a postnatally confirmed IAA, 24% were diagnosed prenatally, which increased from 11% during the first 7-year period to 43% more recently. Also, 15% of the prenatally diagnosed patients with IAA had a family history of structural or genetic anomalies. In fetuses with an IAA, echocardiographic Z-scores for the aortic valve and ascending aorta were significantly lower than in normal fetuses, but the left ventricular dimensions were normal. Aortopulmonary diameter ratios were abnormally low. In conclusion, although the identification of IAA on a prenatal echocardiogram can be challenging, a number of anatomic features can facilitate the diagnosis. In particular, a low aortopulmonary diameter ratio in the absence of a ventricular size discrepancy should prompt consideration of this diagnosis. Despite the diagnostic challenges, the frequency of prenatal diagnosis of the IAA is increasing.

Significance and outcome of left heart hypoplasia in fetal congenital diaphragmatic hernia

OBJECTIVE

In patients with a left-sided congenital diaphragmatic hernia (CDH), the left ventricle (LV) is often compressed and smaller than normal. The objective of this study was to investigate whether small left heart dimensions prenatally normalize after birth in patients with CDH, or whether prenatal indices of left heart size and flow predict postnatal outcome.

METHODS

Clinical and echocardiographic data were reviewed for patients diagnosed with left-sided CDH prenatally. Cardiac dimensions and flows were compared with normative data. Among liveborn patients, pre- and postnatal Z-scores of left heart structures were compared, and associations between prenatal indices and outcome were assessed.

RESULTS

Of 125 patients diagnosed prenatally with CDH, 111 had a left-sided defect. Of these, 85 were liveborn, including 20 with congenital heart disease. Gestational age-adjusted dimensions of fetal left heart structures, including aortic valve diameter, mitral valve (MV) diameter, LV long-axis, LV short-axis and LV volume, were all smaller than normal (P < 0.001). On average, the LV contributed 33 +/- 8% of combined ventricular output, lower than the normal 40-50%. Z-scores of left heart structures increased from the prenatal echocardiogram to the postnatal study, with average changes ranging from 0.56 +/- 1.68 (aortic valve) to 1.39 +/- 1.85 (LV volume). Among liveborn patients, there was no association between prenatal left heart Z-scores and postnatal survival.

CONCLUSIONS

Hypoplasia of and reduced flow through the left heart are common among fetuses with CDH. After birth and CDH repair, left heart dimensions generally normalize, with adequate size to support a biventricular circulation, even when there is very low flow through the left heart in mid- and late-gestation.

Serial cardiopulmonary exercise testing in patients with previous Fontan surgery

Patients with previous Fontan surgery have reduced peak oxygen consumption (Vo 2), and data regarding progression of exercise intolerance is limited. The purpose of this study was to assess the evolution of exercise tolerance in patients with previous Fontan surgery. We performed a retrospective cohort study of patients with previous Fontan surgery who underwent cardiopulmonary exercise testing between November 2002 and January 2009. Patients were required to have completed at least two tests, with adequate levels of effort, >or-6 months apart. We identified 78 patients (55% male) who had undergone a total of 215 cardiopulmonary exercise tests. Age at initial study was 19.7 +/- 10.2 years; time interval since previous Fontan surgery 13.3 +/- 5.7 years; and time interval between the initial and the most recent exercise test was 3.0 +/- 1.4 years. Morphologic left ventricle was present in 58 (74.4%) patients. At baseline, peak Vo 2 averaged 24.7 +/- 7.0 ml/kg/min (63.7% +/- 15.8% predicted). At most recent study, peak Vo 2 averaged 23.2 +/- 7.2 ml/kg/min, (60.4% +/- 13.9% predicted). Percent predicted peak Vo 2 declined slowly, with a mean rate of decline of 1.25 +/- 0.36 percentage points/y (p < 0.001). Most of the decline occurred in patients < 18 years of age (mean rate of decline 1.78 +/- 0.46 percentage points/y; p = 0.0004). Thereafter, the rate of decline was less marked (mean rate of decline 0.54 +/- 0.57 percentage points/y; p = not significant). Ventricular morphology, type of Fontan procedure, and cardiac medications were not predictive of progressive exercise intolerance. In conclusion, although the exercise function of previous Fontan patients tends to decline during late adolescence, it appears to stabilize during early adulthood.

Cerebral blood flow characteristics and biometry in fetuses undergoing prenatal intervention for aortic stenosis with evolving hypoplastic left heart syndrome

Children with hypoplastic left heart syndrome (HLHS) are at risk for neurodevelopmental dysfunction; prenatal factors may play a role in this predilection. Cerebral blood flow profiles are abnormal in fetuses with HLHS, raising the possibility that cerebral hemodynamics in utero may be related to neurodevelopmental abnormalities. Prenatal aortic valvuloplasty for fetal aortic stenosis with evolving HLHS is technically feasible and improves left heart hemodynamics. This study aimed to assess the effects of prenatal intervention on cerebral blood flow profiles and head circumference in fetuses with evolving HLHS. Seventy fetuses underwent prenatal aortic valvuloplasty for evolving HLHS (median 23 weeks gestation). Among 46 fetuses that had successful valvuloplasty and available data, middle cerebral artery (MCA) pulsatility (PI) and resistive (RI) indices were abnormal (Z-scores -1.7+/-1.1 and -2.2+/-1.4, p<0.001). Early post-valvuloplasty (n=33) and at late gestation follow-up (n=28), MCA PI and RI Z-scores remained low with no difference from pre- or early postintervention. Fetal head circumference was normal, as were umbilical artery PI and RI Z-scores. Cerebral blood flow characteristics are abnormal in mid-gestation fetuses with evolving HLHS, suggesting low cerebral vascular impedance. The mechanisms and significance of these abnormalities are unknown. Prenatal aortic valvuloplasty did not have a major impact on these indices. (E-mail: doff.mcelhinney@cardio.chboston.org).

Brain volume and metabolism in fetuses with congenital heart disease: evaluation with quantitative magnetic resonance imaging and spectroscopy

BACKGROUND

Adverse neurodevelopmental outcome is an important source of morbidity in children with congenital heart disease (CHD). A significant proportion of newborns with complex CHD have abnormalities of brain size, structure, or function, which suggests that antenatal factors may contribute to childhood neurodevelopmental morbidity.

METHODS AND RESULTS

Brain volume and metabolism were compared prospectively between 55 fetuses with CHD and 50 normal fetuses with the use of 3-dimensinal volumetric magnetic resonance imaging and proton magnetic resonance spectroscopy. Fetal intracranial cavity volume, cerebrospinal fluid volume, and total brain volume were measured by manual segmentation. Proton magnetic resonance spectroscopy was used to measure the cerebral N-acetyl aspartate: choline ratio (NAA:choline) and identify cerebral lactate. Complete fetal echocardiograms were performed. Gestational age at magnetic resonance imaging ranged from 25 1/7 to 37 1/7 weeks (median, 30 weeks). During the third trimester, there were progressive and significant declines in gestational age-adjusted total brain volume and intracranial cavity volume in CHD fetuses relative to controls. NAA:choline increased progressively over the third trimester in normal fetuses, but the rate of rise was significantly slower (P<0.001) in CHD fetuses. On multivariable analysis adjusted for gestational age and weight percentile, cardiac diagnosis and percentage of combined ventricular output through the aortic valve were independently associated with total brain volume. Independent predictors of lower NAA:choline included diagnosis, absence of antegrade aortic arch flow, and evidence of cerebral lactate (P<0.001).

CONCLUSIONS

Third-trimester fetuses with some forms of CHD have smaller gestational age- and weight-adjusted total brain volumes than normal fetuses and evidence of impaired neuroaxonal development and metabolism. Hemodynamic factors may play an important role in this abnormal development.

Reversible ductus arteriosus constriction due to maternal indomethacin after fetal intervention for hypoplastic left heart syndrome with intact/restrictive atrial septum

OBJECTIVE

Fetal cardiac intervention (FCI) has been performed at our center in selected fetuses with complex congenital heart disease since 2000. Most interventions are performed in fetuses with a ductus arteriosus (DA)-dependent circulation. Indomethacin promotes closure of the DA in newborns and in fetal life, a potentially life threatening complication in fetuses with ductus-dependent congenital heart disease.

METHODS

We reviewed our experience with FCI with a focus on the frequency, features, and clinical course of ductal constriction. Fetuses undergoing FCI receive comprehensive pre- and postoperative cardiac and cerebral ultrasound evaluation, approximately 24 hours before and after the procedure, including imaging of DA flow and Doppler assessment of the umbilical artery and vein, ductus venosus, and, since 2004, the middle cerebral artery.

RESULTS

Among 113 fetuses that underwent FCI, 24 of which were older than 28 0/7 weeks gestation, 2 were found to have DA constriction due to indomethacin therapy within 24 hours of intervention. Both of these were 30-week fetuses with hypoplastic left heart syndrome and restrictive or intact atrial septum. The DA was stenotic by spectral and color Doppler, and middle cerebral and umbilical artery pulsatility indexes were depressed. After discontinuation of indomethacin, the Doppler indices improved or normalized.

CONCLUSION

Close echocardiographic monitoring of fetal Doppler flow velocities is very important after fetal intervention and indomethacin treatment, as the consequences of DA constriction in a fetus with hypoplastic left heart syndrome are potentially lethal. Sonographic evaluation should include measurement of cerebral and umbilical arterial flow velocities as well as color and spectral Doppler interrogation of the DA.

Predictors of technical success and postnatal biventricular outcome after in utero aortic valvuloplasty for aortic stenosis with evolving hypoplastic left heart syndrome

BACKGROUND

Aortic stenosis in the midgestation fetus with a normal-sized or dilated left ventricle predictably progresses to hypoplastic left heart syndrome when associated with certain physiological findings. Prenatal balloon aortic valvuloplasty may improve left heart growth and function, possibly preventing evolution to hypoplastic left heart syndrome.

METHODS AND RESULTS

Between March 2000 and October 2008, 70 fetuses underwent attempted aortic valvuloplasty for critical aortic stenosis with evolving hypoplastic left heart syndrome. We analyzed this experience to determine factors associated with procedural and postnatal outcome. The median gestational age at intervention was 23 weeks. The procedure was technically successful in 52 fetuses (74%). Relative to 21 untreated comparison fetuses, subsequent prenatal growth of the aortic and mitral valves, but not the left ventricle, was improved after intervention. Nine pregnancies (13%) did not reach a viable term or preterm birth. Seventeen patients had a biventricular circulation postnatally, 15 from birth. Larger left heart structures and higher left ventricular pressure at the time of intervention were associated with biventricular outcome. A multivariable threshold scoring system was able to discriminate fetuses with a biventricular outcome with 100% sensitivity and modest positive predictive value.

CONCLUSIONS

Technically successful aortic valvuloplasty alters left heart valvar growth in fetuses with aortic stenosis and evolving hypoplastic left heart syndrome and, in a subset of cases, appeared to contribute to a biventricular outcome after birth. Fetal aortic valvuloplasty carries a risk of fetal demise. Fetuses undergoing in utero aortic valvuloplasty with an unfavorable multivariable threshold score at the time of intervention are very unlikely to achieve a biventricular circulation postnatally.

In utero valvuloplasty for pulmonary atresia with hypoplastic right ventricle: techniques and outcomes

BACKGROUND

Prenatal intervention for fetuses with pulmonary atresia with an intact ventricular septum (PA/IVS) has the potential to alter right heart physiologic features in utero, facilitating right heart growth and improving the prospect of a biventricular outcome after birth.

METHODS

Since 2002, we have considered prenatal intervention for fetal PA/IVS in patients with (1) membranous pulmonary atresia, with identifiable pulmonary valve (PV) leaflets or membrane; (2) an intact or highly restrictive ventricular septum; and (3) right heart hypoplasia, with a tricuspid valve annulus z score of -2 or below and an identifiable but small right ventricle. Intervention was performed through direct cardiac puncture under ultrasound guidance, with percutaneous access or access through a limited laparotomy.

RESULTS

Ten fetuses underwent attempted balloon dilation of the PV in utero. The first 4 procedures were technically unsuccessful, and the most-recent 6 were technically successful. Compared with control fetuses with PA/IVS who did not undergo prenatal intervention and had univentricular outcomes after birth, the tricuspid valve annulus, right ventricle length, and PV annulus grew significantly more from midgestation to late gestation in the 6 fetuses who underwent successful interventions.

CONCLUSIONS

In utero perforation and dilation of the PV in midgestation fetuses with PA/IVS is technically feasible and may be associated with improved right heart growth and postnatal outcomes for fetuses with moderate right heart hypoplasia in midgestation. There is an important learning curve for this procedure, and much remains to be learned about the selection of appropriate fetuses for prenatal intervention.