Impact of Udenafil on Echocardiographic Indices of Single Ventricle Size and Function in FUEL Study Participants.

BACKGROUND: The FUEL trial (Fontan Udenafil Exercise Longitudinal) demonstrated statistical improvements in exercise capacity following 6 months of treatment with udenafil (87.5 mg po BID). The effect of udenafil on echocardiographic measures of single ventricle function in this cohort has not been studied. METHODS: The 400 enrolled participants were randomized 1:1 to udenafil or placebo. Protocol echocardiograms were obtained at baseline and 26 weeks after initiation of udenafil/placebo. Linear regression compared change from baseline indices of single ventricle systolic, diastolic and global function, atrioventricular valve regurgitation, and mean Fontan fenestration gradient in the udenafil cohort versus placebo, controlling for ventricular morphology (left ventricle versus right ventricle/other) and baseline value. RESULTS: The udenafil participants (n=191) had significantly improved between baseline and 26 weeks visits compared to placebo participants (n=195) in myocardial performance index (P=0.03, adjusted mean difference [SE] of changes between groups -0.03[0.01]), atrioventricular valve inflow peak E (P=0.009, 3.95 [1.50]), and A velocities (P=0.034, 3.46 [1.62]), and annular Doppler tissue imaging-derived peak e' velocity (P=0.008, 0.60[0.23]). There were no significant differences in change in single ventricle size, systolic function, atrioventricular valve regurgitation severity, or mean fenestration gradient. Participants with a dominant left ventricle had significantly more favorable baseline values of indices of single ventricle size and function (lower volumes and areas, E/e' ratio, systolic:diastolic time and atrioventricular valve regurgitation, and higher annular s' and e' velocity). CONCLUSIONS: FUEL participants who received udenafil demonstrated a statistically significant improvement in some global and diastolic echo indices. Although small, the changes in diastolic function suggest improvement in pulmonary venous return and/or augmented ventricular compliance, which may help explain improved exercise performance in that cohort. REGISTRATION: URL: https://clinicaltrials.gov; Unique Identifier: NCT02741115.

Long-term cardiovascular safety of fenfluramine in patients with Dravet syndrome treated for up to 3 years: Findings from serial echocardiographic assessments.

OBJECTIVE: To assess the cardiovascular safety of fenfluramine when used to treat children and young adults with Dravet syndrome. METHODS: Patients with Dravet syndrome who completed one of three phase 3 clinical trials of fenfluramine could enroll in the open-label extension (OLE) study (NCT02823145). All patients started fenfluramine treatment at an oral dose of 0.2 mg/kg/day. The dose was titrated based on efficacy and tolerability to a maximum of 0.7 mg/kg/day (absolute maximum 26 mg/day) or 0.4 mg/kg/day (absolute maximum 17 mg/day) in patients concomitantly receiving stiripentol. Serial transthoracic echocardiography was performed using standardized methods and blinded readings at OLE entry, after 4-6 weeks, and every 3 months thereafter. Valvular heart disease (VHD) was defined as ≥ moderate mitral regurgitation or ≥ mild aortic regurgitation combined with physical signs or symptoms attributable to valve dysfunction. Pulmonary artery hypertension (PAH) was defined as systolic pulmonary artery pressure >35 mmHg. RESULTS: A total of 327 patients (median age, 9.0 years; range, 2-19 years) have enrolled in the OLE and received ≥1 dose of fenfluramine. The median duration of treatment was 23.9 months (range, 0.2-42.6 months) and the median dose of fenfluramine was 0.44 mg/kg/day. No patient demonstrated VHD or PAH at any time during the OLE. SIGNIFICANCE/INTERPRETATION: This study, which represents the largest, longest, and most rigorous examination of cardiovascular safety of fenfluramine yet reported, found no cases of VHD or PAH. These results, combined with fenfluramine's substantial antiseizure efficacy, support a strong positive benefit-risk profile for fenfluramine in the treatment of Dravet syndrome.

Coronary Artery Changes in Patients with Multisystem Inflammatory Syndrome in Children: Los Angeles Experience.

We compared cardiac findings in patients with multisystem inflammatory syndrome in children and Kawasaki disease in the first 6 months of the 2020 coronavirus disease pandemic to patients with Kawasaki disease during 2016-2019. We saw a high rate of coronary aneurysms in 2020, with a similar rate of coronary involvement but greater volume and incidence of cardiac dysfunction compared with previous years.

Cardiovascular safety of fenfluramine in the treatment of Dravet syndrome: Analysis of an ongoing long-term open-label safety extension study.

OBJECTIVE: Fenfluramine, which was previously approved as a weight loss drug, was withdrawn in 1997 when reports of cardiac valvulopathy emerged. The present study was conducted in part to characterize the cardiovascular safety profile of low-dose fenfluramine when used in a pediatric population to reduce seizure frequency in patients with Dravet syndrome. METHODS: Patients 2- to 18-years-old with Dravet syndrome who had completed any of three randomized, placebo-controlled clinical trials of fenfluramine were offered enrollment in this open-label extension (OLE) study. All patients were treated with fenfluramine starting at a dose of 0.2 mg/kg/day (oral solution dosed twice per day), which was titrated to maximal effect with a dose limit of 0.7 mg/kg/day (maximum 26 mg/day) or 0.4 mg/kg/day (maximum 17 mg/day) in patients receiving concomitant stiripentol. Standardized echocardiographic examinations were conducted at Week 4 or 6 and then every 3 months during the OLE study to monitor cardiac valve function and structure and pulmonary artery pressure. The primary end point for the echocardiography analysis was the number of patients who developed valvular heart disease or pulmonary artery hypertension (PAH) during treatment. RESULTS: A total of 232 patients were enrolled in the study. The average age of patients was 9.1 ± 4.7 years, and 55.2% were male. The median duration of treatment with fenfluramine was 256 days (range = 58-634 days), and the mean dose of fenfluramine was 0.41 mg/kg/day. No cases of valvular heart disease or PAH were observed. SIGNIFICANCE: Longitudinal echocardiography over a median 8.4 months of treatment with fenfluramine suggests a low risk of developing cardiac valvulopathy and PAH when used to treat pediatric patients with Dravet syndrome.

Further percutaneous dilation of a Melody® valve in the mitral position to accommodate somatic growth in a small child: lessons learned.

A 15-month-old child underwent percutaneous expansion of a Melody transcatheter pulmonary valve in the mitral position to accommodate growth after initial surgical implantation during infancy, but transiently decompensated after valvuloplasty owing to stent malformation. The Melody valve in the mitral position of small patients can be further expanded by percutaneous dilation, but there are a number of potential complications and technical improvements to consider.

Morphology of intramural ventricular septal defects: Clinical imaging and autopsy correlation.

An intramural ventricular septal defect (IVSD) is a type of interventricular communication that can occur following biventricular repair of a conotruncal malformation. There have been no previous reports depicting the actual pathologic anatomy of this defect. We describe two cases of IVSDs with their clinical imaging and postmortem pathology.

Respiratory syncytial virus hospitalization risk in the second year of life by specific congenital heart disease diagnoses.

Children with hemodynamically significant congenital heart disease (CHD) are at elevated risk of morbidity and mortality due to respiratory syncytial virus (RSV) disease compared to their healthy peers. Previous studies have demonstrated lower RSV hospitalization risk among all children with CHD at 12-23 months of age versus 0-11 months of age. However, RSV hospitalization risk at 12-23 months of age by specific CHD diagnosis has not been characterized. Both case-control and cohort studies were conducted using data from the US National Inpatient Sample from 1997 to 2013 to characterize relative risk of RSV hospitalization among children 12-23 months of age with CHD. Related CHD diagnoses were combined for analysis. Hospitalizations for RSV and unspecified bronchiolitis were described by length of stay, mechanical ventilation use, mortality, and total charges. Over the 17-year period, 1,168,886 live birth hospitalizations with CHD were identified. Multiple specific CHD conditions had an elevated odds ratio or relative risk of RSV hospitalization. Mean total RSV hospitalization charges were significantly higher among children with CHD relative to those without CHD ($19,650 vs $7,939 in 2015 dollars) for this period. Compared to children without CHD, children with Ebstein's anomaly, transposition of the great arteries, aortic stenosis, heterotaxia, and aortic arch anomalies had 367-, 344-, 203-, 117- and 47-fold increased risk of inpatient RSV mortality, respectively. Unspecified bronchiolitis hospitalization odds and relative risk across CHD diagnoses were similar to those observed with RSV hospitalization; however, unspecified bronchiolitis hospitalizations were associated with shorter mean days of stay and less frequently associated with mechanical ventilation or mortality. Among children with more severe CHD diagnoses, RSV disease remains an important health risk through the second year of life. These data can help inform decisions regarding interventions to protect children with CHD from severe RSV disease during their second year of life.

The Logistics and Coordination of Respiratory Syncytial Virus Immunoprophylaxis Use Among US Pediatric Specialists.

This study was conducted to survey US pediatric specialists about administration of respiratory syncytial virus (RSV) immunoprophylaxis, communication patterns among physicians and parents, and barriers to access. Separate surveys were sent to neonatologists, pediatricians, pediatric pulmonologists, and pediatric cardiologists. Most physicians (≥93.5%) routinely recommended immunoprophylaxis to high-risk children. Most respondents (≥71.8%) reported that >50.0% of eligible infants and young children received each monthly dose throughout the RSV season, with the first dose most commonly administered before discharge from the birth hospitalization. To ensure receipt of subsequent doses, specialists frequently scheduled a follow-up visit at the end of the current appointment. All specialists reported insurance denials as the biggest obstacle to the administration of immunoprophylaxis to high-risk children. These findings may be used to improve adherence to immunoprophylaxis by enhancing education and physician-parent communications about severe RSV disease prevention, and by reducing known barriers to use of this preventive therapy.

Perceived Risk of Severe Respiratory Syncytial Virus Disease and Immunoprophylaxis Use Among US Pediatric Specialists.

This study was conducted to assess the perception of US pediatric specialists of respiratory syncytial virus (RSV) disease risk and determine their clinical practices regarding immunoprophylaxis for high-risk children. Separate surveys were sent to neonatologists, pediatricians, pediatric pulmonologists, and pediatric cardiologists. Data were collected using structured questions requiring quantitative responses. Most neonatologists and pediatricians (>82.7%) reported a high clinical need for RSV immunoprophylaxis in preterm infants <32 weeks' gestational age. Pediatric pulmonologists and pediatric cardiologists suggested that health conditions indicative of chronic lung disease of prematurity and hemodynamically significant congenital heart disease, respectively, confer eligibility for RSV immunoprophylaxis. Agreement with the changes in the 2014 American Academy of Pediatrics guidance for RSV immunoprophylaxis was mixed among respondents from the 4 specialties. Survey findings may provide a basis to improve education about risk for severe RSV disease and evaluate changes in physician use of RSV immunoprophylaxis based on the 2014 guidance.

Impact of initial norwood shunt type on right ventricular deformation: the single ventricle reconstruction trial.

BACKGROUND: The Single Ventricle Reconstruction trial demonstrated a transplantation-free survival advantage at 12-month follow-up for patients with right ventricle-pulmonary artery shunts (RVPAS) with the Norwood procedure compared with modified Blalock-Taussig shunts but similar survival and decreased global right ventricular (RV) function on longer term follow-up. The impact of the required ventriculotomy for the RVPAS remains unknown. The aim of this study was to compare echocardiography-derived RV deformation indices after stage 2 procedures in survivors with single RV anomalies enrolled in the Single Ventricle Reconstruction trial. METHODS: Global and regional RV systolic longitudinal and circumferential strain and strain rate, ejection fraction, and short-axis percentage fractional area change were all derived by speckle-tracking echocardiography from protocol echocardiograms obtained at 14.3 ± 1.2 months. Student t tests or Wilcoxon rank sum tests were used to compare groups. RESULTS: The cohort included 275 subjects (129 in the modified Blalock-Taussig shunt group and 146 in the RVPAS group). Longitudinal deformation could be quantified in 214 subjects (78%) and circumferential measures in 182 subjects (66%). RV ejection fraction and percentage fractional area change did not differ between groups. There were no significant differences between groups for global or regional longitudinal deformation. Circumferential indices showed abnormalities in deformation in the RVPAS group, with decreased global circumferential strain (P = .05), strain rate (P = .09), and anterior regional strain rate (P = .07) that approached statistical significance. CONCLUSIONS: RV myocardial deformation at 14 months, after stage 2 procedures, was not significantly altered by the type of initial shunt placed. However, abnormal trends were appreciated in circumferential deformation for the RVPAS group in the area of ventriculotomy that may represent early myocardial dysfunction. These data provide a basis for longer term RV deformation assessment in survivors after Norwood procedures.

Unguarded mitral orifice associated with hypoplastic left heart syndrome.

In the spectrum of mitral valve anomalies, unguarded mitral orifice is an exceedingly rare malformation, with only four cases described in the current literature. All previously reported cases have been associated with discordant atrioventricular connections. We describe the first known case of unguarded mitral valve orifice, in the setting of atrioventricular concordance, in a newborn with hypoplastic left heart syndrome.

Impact of initial shunt type on cardiac size and function in children with single right ventricle anomalies before the Fontan procedure: the single ventricle reconstruction extension trial.

BACKGROUND: In children with single right ventricular (RV) anomalies, changes in RV size and function may be influenced by shunt type chosen at the time of the Norwood procedure. OBJECTIVES: The study sought to identify shunt-related differences in echocardiographic findings at 14 months and ≤6 months pre-Fontan in survivors of the Norwood procedure. METHODS: We compared 2-dimensional and Doppler echocardiographic indices of RV size and function, neo-aortic and tricuspid valve annulus dimensions and function, and aortic size and patency at 14.1 ± 1.2 months and 33.6 ± 9.6 months in subjects randomized to a Norwood procedure using either the modified Blalock-Taussig shunt (MBTS) or right ventricle to pulmonary artery shunt (RVPAS). RESULTS: Acceptable echocardiograms were available at both time points in 240 subjects (114 MBTS, 126 RVPAS). At 14 months, all indices were similar between shunt groups. From the 14-month to pre-Fontan echocardiogram, the MBTS group had stable indexed RV volumes and ejection fraction, while the RVPAS group had increased RV end-systolic volume (p = 0.004) and decreased right ventricular ejection fraction (RVEF) (p = 0.004). From 14 months to pre-Fontan, the treatment groups were similar with respect to decline in indexed neo-aortic valve area, >mild neo-aortic valve regurgitation (<5% at each time), indexed tricuspid valve area, and ≥moderate tricuspid valve regurgitation (<20% at each time). CONCLUSIONS: Initial Norwood shunt type influences pre-Fontan RV remodeling during the second and third years of life in survivors with single RV anomalies, with greater RVEF deterioration after RVPAS. Encouragingly, other indices of RV function remain stable before Fontan regardless of shunt type. (Comparison of Two Types of Shunts in Infants with Single Ventricle Defect Undergoing Staged Reconstruction-Pediatric Heart Network; NCT00115934).

Absent aortic valve associated with double outlet right ventricle and aortopulmonary window: physiologic implications of a rare malformation in both the fetus and neonate.

Absence of the aortic valve is a rare congenital heart defect that is detectable in the prenatal period. In this condition, functional aortic valve leaflets are absent; in their place are rudimentary, immobile noncoapting plate-like structures at the level of the annulus resulting in severe aortic regurgitation. We report the fetal diagnosis and subsequent postnatal course of an infant with the novel association of absent aortic valve, double outlet right ventricle, and aortopulmonary window. This unique combination of defects resulted in an unusual pattern of circular shunting that produced evidence of fetal heart failure. Shortly after birth, the abnormal physiology led to compromised systemic perfusion, intestinal perforation and subsequent rapid demise of the patient. Abrupt postnatal deterioration typifies the vast majority of the absent aortic valve cases found in the literature. Our patient is unique in that it is the first female reported with absent aortic valve and the first reported with an aortopulmonary window. This report demonstrates that absent aortic valve is a condition that can be diagnosed prenatally by fetal echocardiogram; the highly abnormal physiology places these patients at risk for fetal heart failure. Given the potential for clinical instability and rapid deterioration after birth, such patients should undergo rapid postnatal assessment and immediate surgical intervention when deemed appropriate.

Multicenter study comparing shunt type in the norwood procedure for single-ventricle lesions: three-dimensional echocardiographic analysis.

BACKGROUND: The Pediatric Heart Network's Single Ventricle Reconstruction (SVR) trial randomized infants with single right ventricles (RVs) undergoing a Norwood procedure to a modified Blalock-Taussig or RV-to-pulmonary artery shunt. This report compares RV parameters in the 2 groups using 3-dimensional echocardiography. METHODS AND RESULTS: Three-dimensional echocardiography studies were obtained at 10 of 15 SVR centers. Of the 549 subjects, 314 underwent 3-dimensional echocardiography studies at 1 to 4 time points (pre-Norwood, post-Norwood, pre-stage II, and 14 months) for a total of 757 3-dimensional echocardiography studies. Of these, 565 (75%) were acceptable for analysis. RV volume, mass, mass:volume ratio, ejection fraction, and severity of tricuspid regurgitation did not differ by shunt type. RV volumes and mass did not change after the Norwood, but increased from pre-Norwood to pre-stage II (end-diastolic volume [milliliters]/body surface area [BSA](1.3), end-systolic volume [milliliters]/BSA(1.3), and mass [grams]/BSA(1.3) mean difference [95% confidence interval]=25.0 [8.7-41.3], 19.3 [8.3-30.4], and 17.9 [7.3-28.5], then decreased by 14 months (end-diastolic volume/BSA(1.3), end-systolic volume/BSA(1.3), and mass/BSA(1.3) mean difference [95% confidence interval]=-24.4 [-35.0 to -13.7], -9.8 [-17.9 to -1.7], and -15.3 [-22.0 to -8.6]. Ejection fraction decreased from pre-Norwood to pre-stage II (mean difference [95% confidence interval]=-3.7 [-6.9 to -0.5]), but did not decrease further by 14 months. CONCLUSIONS: We found no statistically significant differences between study groups in 3-dimensional echocardiography measures of RV size and function, or magnitude of tricuspid regurgitation. Volume unloading was seen after stage II, as expected, but ejection fraction did not improve. This study provides insights into the remodeling of the operated univentricular RV in infancy.

Doppler flow patterns in the right ventricle-to-pulmonary artery shunt and neo-aorta in infants with single right ventricle anomalies: impact on outcome after initial staged palliations.

BACKGROUND: A Pediatric Heart Network trial compared outcomes in infants with single right ventricle anomalies undergoing Norwood procedures randomized to modified Blalock-Taussig shunt (MBTS) or right ventricle-to-pulmonary artery shunt (RVPAS). Doppler patterns in the neo-aorta and RVPAS may characterize physiologic changes after staged palliations that affect outcomes and right ventricular (RV) function. METHODS: Neo-aortic cardiac index (CI), retrograde fraction (RF) in the descending aorta and RVPAS conduit, RVPAS/neo-aortic systolic ejection time ratio, and systolic/diastolic (S/D) ratio were measured early after Norwood, before stage II palliation, and at 14 months. These parameters were compared with transplantation-free survival, length of hospital stay, and RV functional indices. RESULTS: In 529 subjects (mean follow-up period, 3.0 ± 2.1 years), neo-aortic CI and descending aortic RF were significantly higher in the MBTS cohort after Norwood. The RVPAS RF averaged <25% at both interstage intervals. Higher pre-stage II descending aortic RF was correlated with lower RV ejection fraction (R = -0.24; P = .032) at 14 months for the MBTS cohort. Higher post-Norwood CI (5.6 vs 4.4 L/min/m(2), P = .04) and lower S/D ratio (1.40 vs 1.68, P = .01) were correlated with better interstage transplantation-free survival for the RVPAS cohort. No other Doppler flow patterns were correlated with outcomes. CONCLUSIONS: After the Norwood procedure, infants tolerated significant descending aortic RF (MBTS) and conduit RF (RVPAS), with little correlation with clinical outcomes or RV function. Neo-aortic CI, ejection time, and S/D ratios also had limited correlations with outcomes or RV function, but higher post-Norwood neo-aortic CI and lower S/D ratio were correlated with better interstage survival in those with RVPAS.