Current Understanding of Indications, Technical Aspects and Outcomes of Fetal Cardiac Interventions.

With the improvement in the detection of congenital heart disease in fetal life, fetal cardiac interventions are pushing the envelope in hopes of either altering the natural history of disease or improving survival in certain high-risk lesions. These interventions include fetal aortic valvuloplasty for evolving hypoplastic left heart syndrome, fetal atrial septoplasty with or without atrial septal stenting for hypoplastic left heart syndrome and variants with intact or severely restrictive atrial septum, and fetal pulmonary valvuloplasty for severe pulmonary stenosis or pulmonary atresia with intact ventricular septum. This review discusses their indications, technical aspects, and outcomes based on available literature.

Mitral Annular Disjunction and Its Progression during Childhood in Marfan Syndrome.

BACKGROUND: Data on mitral annular disjunction (MAD) in children with Marfan syndrome (MFS) are sparse. OBJECTIVES: To investigate the diagnostic yield of MAD by echocardiography and cardiac magnetic resonance imaging (CMR), its prevalence and progression during childhood. METHODS: We included patients <21 years old with MFS, defined by 2010 Ghent criteria and a pathogenic FBN1 variant or ectopia lentis. Two readers measured systolic separation between the mitral valve (MV) posterior hinge point and left ventricular (LV) myocardium on initial and subsequent imaging. MAD was defined as MV-LV separation ≥2 mm, MV prolapse (MVP) as atrial displacement ≥2 mm. Kappa coefficients evaluated echocardiogram-CMR agreement. Bland-Altman and intraclass correlation coefficients (ICC) assessed interrater and intermodality reliability. Univariable mixed-effects linear regression was used to evaluate longitudinal changes of MAD. RESULTS: MAD was detected in 60% (110/185) eligible patients. MVP was present in 48% (53/110) of MAD and MAD in 90% (53/59) of MVP. MAD detection by CMR and echocardiography had 96% overall agreement (Kappa = 0.89, p < 0.001) and a 0.32-mm estimate bias (95%CI 0.00, 0.65). ICC by echocardiography, CMR, and between modalities were 0.97 (95%CI 0.93, 0.98), 0.92 (95%CI 0.79, 0.97), and 0.91 (95%CI 0.85, 0.94), respectively. MAD was associated with aortic root dilation (p < 0.001). MAD was found in children of all ages, increased +0.18 mm/year (95%CI +0.14, + 0.22) during a median duration of 5.5 years (IQR 3.1, 7.5 years). MAD indexed by height yielded a constant value +0.0002 mm/m/year (95%CI -0.0002, + 0.0005 mm/m/year). CONCLUSIONS: MAD was common in pediatric MFS and was associated with aortic root dilation. MAD detection by echocardiography and CMR was highly reliable, suggesting that routine assessment in MFS is feasible. MAD was present in neonates and progressed over time but remained constant when indexing by height. Further studies are needed to evaluate MAD as a biomarker for clinical outcomes in pediatric MFS.

Emergence of the natural history of Myhre syndrome: 47 patients evaluated in the Massachusetts General Hospital Myhre Syndrome Clinic (2016-2023).

Myhre syndrome is an increasingly diagnosed ultrarare condition caused by recurrent germline autosomal dominant de novo variants in SMAD4. Detailed multispecialty evaluations performed at the Massachusetts General Hospital (MGH) Myhre Syndrome Clinic (2016-2023) and by collaborating specialists have facilitated deep phenotyping, genotyping and natural history analysis. Of 47 patients (four previously reported), most (81%) patients returned to MGH at least once. For patients followed for at least 5 years, symptom progression was observed in all. 55% were female and 9% were older than 18 years at diagnosis. Pathogenic variants in SMAD4 involved protein residues p.Ile500Val (49%), p.Ile500Thr (11%), p.Ile500Leu (2%), and p.Arg496Cys (38%). Individuals with the SMAD4 variant p.Arg496Cys were less likely to have hearing loss, growth restriction, and aortic hypoplasia than the other variant groups. Those with the p.Ile500Thr variant had moderate/severe aortic hypoplasia in three patients (60%), however, the small number (n = 5) prevented statistical comparison with the other variants. Two deaths reported in this cohort involved complex cardiovascular disease and airway stenosis, respectively. We provide a foundation for ongoing natural history studies and emphasize the need for evidence-based guidelines in anticipation of disease-specific therapies.

Evidence of cardiomyopathy associated with Marfan syndrome in children.

OBJECTIVE: Marfan syndrome (MFS)-associated cardiomyopathy, defined as ventricular dilation and dysfunction unexplained by volume loading, is not well defined in children. This study evaluated ventricular size and function in paediatric MFS using cardiac MRI (cMRI). METHODS: This retrospective cohort study examined patients with MFS <19 years old at first cMRI. Left ventricular (LV) ejection fraction (EF) <55% was considered abnormal, as were z-scores >2. Combined mitral and aortic regurgitation indexed to LV stroke volume <20% defined absent/mild volume load. Biventricular volumes and EF on serial cMRI studies were compared with normative paediatric cMRI values, with measures converted to z-scores as appropriate. Longitudinal changes in volumes and EF were evaluated by mixed linear regression. Associations between ventricular, aortic and mitral characteristics were evaluated. RESULTS: 58 patients (60% male) were evaluated. Median age at initial cMRI was 13.6 years (IQR 10.0-15.8 years). Among patients with absent/mild LV volume load at initial cMRI (n=44, 76%), indexed LV end-diastolic volume (EDV) was significantly increased above normative values (median z-score 1.8, IQR 0.6-3.5, p<0.0001) and LVEF was abnormal in 48% (21/44). In the absence of volume loading, mitral valve prolapse (MVP) was associated with larger ventricular volumes and lower LVEF. Among those with serial cMRIs, LVEF and EDV z-scores did not significantly change over a mean follow-up time between cMRI studies of 1.5 years. CONCLUSION: Ventricular dilation and reduced EF are common in children with MFS and occur with no/mild LV volume load, suggesting intrinsic cardiomyopathy. MVP may be associated with cardiomyopathy.

Bicuspid Aortic Valve Disease With Early Onset Complications: Characteristics And Aortic Outcomes.

Bicuspid aortic valve (BAV) is the most common congenital heart malformation in adults but can also cause childhood-onset complications. In multicenter study, we found that adults who experience significant complications of BAV disease before age 30 are distinguished from the majority of BAV cases that manifest after age 50 by a relatively severe clinical course, with higher rates of surgical interventions, more frequent second interventions, and a greater burden of congenital heart malformations. These observations highlight the need for prompt recognition, regular lifelong surveillance, and targeted interventions to address the significant health burdens of patients with early onset BAV complications.

Genetic Testing for Supravalvar Aortic Stenosis: What to Do When It Is Not Williams Syndrome.

BACKGROUND: We aimed to describe the frequency and yield of genetic testing in supravalvar aortic stenosis (SVAS) following negative evaluation for Williams-Beuren syndrome (WS). METHODS AND RESULTS: This retrospective cohort study included patients with SVAS at our institution who had a negative evaluation for WS from May 1991 to September 2021. SVAS was defined as (1) peak supravalvar velocity of ≥2 meters/second, (2) sinotubular junction or ascending aortic Z score <-2.0, or (3) sinotubular junction Z score <-1.5 with family history of SVAS. Patients with complex congenital heart disease, aortic valve disease as the primary condition, or only postoperative SVAS were excluded. Genetic testing and diagnoses were reported. Of 162 patients who were WS negative meeting inclusion criteria, 61 had genetic testing results available (38%). Chromosomal microarray had been performed in 44 of 61 and was nondiagnostic for non-WS causes of SVAS. Sequencing of 1 or more genes was performed in 47 of 61. Of these, 39 of 47 underwent ELN sequencing, 20 of 39 (51%) of whom had a diagnostic variant. Other diagnoses made by gene sequencing were Noonan syndrome (3 PTPN11, 1 RIT1), Alagille syndrome (3 JAG1), neurofibromatosis (1 NF1), and homozygous familial hypercholesterolemia (1 LDLR1). Overall, sequencing was diagnostic in 29 of 47 (62%). CONCLUSIONS: When WS is excluded, gene sequencing for SVAS is high yield, with the highest yield for the ELN gene. Therefore, we recommend gene sequencing using a multigene panel or exome analysis. Hypercholesterolemia can also be considered in individuals bearing the stigmata of this disease.

NODAL variants are associated with a continuum of laterality defects from simple D-transposition of the great arteries to heterotaxy.

BACKGROUND: NODAL signaling plays a critical role in embryonic patterning and heart development in vertebrates. Genetic variants resulting in perturbations of the TGF-ß/NODAL signaling pathway have reproducibly been shown to cause laterality defects in humans. To further explore this association and improve genetic diagnosis, the study aims to identify and characterize a broader range of NODAL variants in a large number of individuals with laterality defects. METHODS: We re-analyzed a cohort of 321 proband-only exomes of individuals with clinically diagnosed laterality congenital heart disease (CHD) using family-based, rare variant genomic analyses. To this cohort we added 12 affected subjects with known NODAL variants and CHD from institutional research and clinical cohorts to investigate an allelic series. For those with candidate contributory variants, variant allele confirmation and segregation analysis were studied by Sanger sequencing in available family members. Array comparative genomic hybridization and droplet digital PCR were utilized for copy number variants (CNV) validation and characterization. We performed Human Phenotype Ontology (HPO)-based quantitative phenotypic analyses to dissect allele-specific phenotypic differences. RESULTS: Missense, nonsense, splice site, indels, and/or structural variants of NODAL were identified as potential causes of heterotaxy and other laterality defects in 33 CHD cases. We describe a recurrent complex indel variant for which the nucleic acid secondary structure predictions implicate secondary structure mutagenesis as a possible mechanism for formation. We identified two CNV deletion alleles spanning NODAL in two unrelated CHD cases. Furthermore, 17 CHD individuals were found (16/17 with known Hispanic ancestry) to have the c.778G > A:p.G260R NODAL missense variant which we propose reclassification from variant of uncertain significance (VUS) to likely pathogenic. Quantitative HPO-based analyses of the observed clinical phenotype for all cases with p.G260R variation, including heterozygous, homozygous, and compound heterozygous cases, reveal clustering of individuals with biallelic variation. This finding provides evidence for a genotypic-phenotypic correlation and an allele-specific gene dosage model. CONCLUSION: Our data further support a role for rare deleterious variants in NODAL as a cause for sporadic human laterality defects, expand the repertoire of observed anatomical complexity of potential cardiovascular anomalies, and implicate an allele specific gene dosage model.

Design and implementation of multicenter pediatric and congenital studies with cardiovascular magnetic resonance: Big data in smaller bodies.

Cardiovascular magnetic resonance (CMR) has become the reference standard for quantitative and qualitative assessment of ventricular function, blood flow, and myocardial tissue characterization. There is a preponderance of large CMR studies and registries in adults; However, similarly powered studies are lacking for the pediatric and congenital heart disease (PCHD) population. To date, most CMR studies in children are limited to small single or multicenter studies, thereby limiting the conclusions that can be drawn. Within the PCHD CMR community, a collaborative effort has been successfully employed to recognize knowledge gaps with the aim to embolden the development and initiation of high-quality, large-scale multicenter research. In this publication, we highlight the underlying challenges and provide a practical guide toward the development of larger, multicenter initiatives focusing on PCHD populations, which can serve as a model for future multicenter efforts.

Labyrinthine cor triatriatum sinister in fetal hypoplastic left heart syndrome is associated with poor outcomes.

OBJECTIVES: A subset of hypoplastic-left-heart-syndrome (HLHS) fetuses have a complex cor-triatriatum sinister that we named "labyrinthine-cor (L-cor)". We sought to determine the prevalence of L-cor in HLHS fetuses and hypothesized that it is associated with increased mortality. METHODS: This single-center retrospective cohort study included all HLHS fetuses from January 2010-December 2020. Fetuses with other hypoplastic-left-heart variants, inadequate images, lack of follow-up and fetal atrial-septal interventions were excluded. RAS was defined as the ratio of pulmonary-vein forward-to-reverse velocity-time-integral (VTI) ≤ 5 and severe-RAS defined as VTI-ratio <3. Kaplan-Meier survival-analysis was performed for the primary outcome of transplant-free survival for 62 weeks after gestational-age of 30 weeks (∼1 year). RESULTS: Of the 156 consecutive fetuses with HLHS, 11 (7.7%) had L-cor and 8/11 (72.7%) of these had RAS. When compared to HLHS-RAS without L-cor, fetuses with HLHS-RAS and L-cor were less likely to survive to 28 days (87% vs. 62.5%, p = 0.017) and to 1 year (69.6% vs. 25%, p = 0.029). When comparing by survival analysis, fetuses with severe-RAS with L-cor had lower survival compared severe-RAS without L-cor (p = 0.020). CONCLUSION: L-cor in fetal HLHS is associated with increased mortality. Recognition of this finding is important for prognostication and atrial-septal-intervention planning.

Whole Exome Sequencing Uncovers the Genetic Complexity of Bicuspid Aortic Valve in Families with Early Onset Complications.

Bicuspid Aortic Valve (BAV) is the most common adult congenital heart lesion with an estimated population prevalence of 1%. We hypothesize that early onset complications of BAV (EBAV) are driven by specific impactful genetic variants. We analyzed whole exome sequences (WES) to identify rare coding variants that contribute to BAV disease in 215 EBAV families. Predicted pathogenic variants of causal genes were present in 111 EBAV families (51% of total), including genes that cause BAV (8%) or heritable thoracic aortic disease (HTAD, 17%). After appropriate filtration, we also identified 93 variants in 26 novel genes that are associated with autosomal dominant congenital heart phenotypes, including recurrent deleterious variation of FBN2, MYH6, channelopathy genes, and type 1 and 5 collagen genes. These findings confirm our hypothesis that unique rare genetic variants contribute to early onset complications of BAV disease.

Fetal Diagnosis of Supravalvular Aortic Stenosis and Pulmonary Stenosis in a Family with Non-Syndromic Elastin Mutation.

Supravalvular aortic stenosis (SVAS) has been well described in Williams-Beuren Syndrome and non-syndromic elastin (ELN) mutations. Non-syndromic ELN mutations are inherited in an autosomal dominant pattern with incomplete penetrance and variable expressivity. ELN haploinsufficiency leads to progressive arteriopathy, typically affecting the aortic sinotubular junction. Multi-level pulmonary stenosis has also been reported and biventricular obstruction may portend a worse prognosis. Fetal presentation of ELN mutation with SVAS has not been previously reported in the literature. We present a case of fetal diagnosis of SVAS and multi-level pulmonary stenosis in a family with a known pathogenic ELN mutation (Exon 6, c.278del [p.Pro93Leufs*29]). On the fetus' initial fetal echo, there was only mild flow acceleration through the aortic outflow tract, however, she went on to develop progressive bilateral obstruction. In the early post-natal period, the child was clinically asymptomatic and showed similar mild SVAS and mild valvar and supravalvular pulmonary stenosis. Our case highlights the need for serial monitoring of fetuses with suspected or confirmed ELN arteriopathy.

Evaluating Variation in the Cardiac Management of Children with Hereditary Thoracic Aortic Disease in the United States.

Hereditary thoracic aortic diseases (HTAD) such as Marfan syndrome (MFS), Loeys-Dietz syndrome (LDS), and vascular Ehlers-Danlos syndrome (VEDS) frequently result in complex cardiovascular pathology that can lead to premature death. However, given limited research and lack of detailed pediatric management guidelines, practice in the U.S. is largely guided by personal experience and/or advice from other professionals. A REDCap survey was composed that covered topics including genetic testing, imaging, and medication choice (all in children), among others. After piloting, the survey was distributed via email and advertised on PediHeartNet. Email addresses of providers were obtained through an established aortic research collaborative and a clinic directory offered through The Marfan Foundation. There were 64 survey responses (pediatric cardiologists 66%; geneticists 13%, genetic counselors 6%; the remaining 15% was comprised of a combination of cardiothoracic surgeons, adult cardiologists, adult congenital specialists, combined cardiology and genetics specialist, nurse practitioners, physician assistants, and nurse coordinators). The most supported indication for genetic evaluation in a child with mild aortic root dilation was family history of thoracic aortic dissection (100%), in contrast to mild root dilation with no other HTAD features (39% supported, 45% did not, 15% saying it would depend on other factors). The majority would start medical therapy in MFS at an aortic root z-score of 2, however differences existed regarding medication preferences for initiation (47% angiotensin receptor blockers, 36% beta blockers, 17% would not or cannot prescribe medication/defer medication choice to another provider). Variation existed for cross-sectional imaging indications and modality and for exercise restrictions, although on average respondents were more lenient than the Bethesda guidelines. While there are areas of general agreement in the cardiac management of children with HTAD, there are also several areas of considerable variation. This highlights the need for additional study in these areas with the ultimate goal of creating consensus guidelines.

Atrial septal defect closure is associated with improved clinical status in patients ≤ 10 kg with bronchopulmonary dysplasia.

Patients with bronchopulmonary dysplasia (BPD) have shown clinical improvement after secundum atrial septal defect (ASD) closure. We sought to determine if this post-ASD closure improvement is secondary to the expected course in BPD patients or related to the closure itself. A novel BPD-ASD score was created to assess patients' clinical status (higher score = worse disease) and applied to 10 BPD-ASD inpatients weighing ≤ 10 kg who underwent ASD closure. The score and its subcomponents were retrospectively calculated serially ranging from 8 weeks pre- to 8 weeks post-intervention, and pre- and post-intervention score slopes were created. These slopes were compared using mixed regression modeling with an interaction term. There was a significant difference in pre- versus post-intervention slope with the most score drop the first week post-intervention (-2.1 + /- 0.8, p = 0.014). The mean score also dropped through weeks 2 (slope -0.8 + /- 0.8, p = 0.013) and 4 (slope -1.0 + /- 0.5, p = 0.001) post-intervention. There was a significant difference in pre- and post-intervention slopes for diuretics (p = 0.018) and the combined score of respiratory support, FiO2 need, and respiratory symptoms (p = 0.018). This study demonstrated significant improvement in BPD-ASD score, diuretic need, and respiratory status after ASD closure in BPD-ASD patients ≤ 10 kg that was outside of the natural course of BPD. Our study was limited by its small, single-center, retrospective nature. Future studies should be performed in a larger multicenter population to both validate the scoring system and compare to non-intervention infants.

Vertebral Tortuosity Is Associated With Increased Rate of Cardiovascular Events in Vascular Ehlers-Danlos Syndrome.

Background Arterial tortuosity is associated with adverse events in Marfan and Loeys-Dietz syndromes but remains understudied in Vascular Ehlers-Danlos syndrome. Methods and Results Subjects with a pathogenic COL3A1 variant diagnosed at age <50 years were included from 2 institutions and the GenTAC Registry (National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions). Height-adjusted vertebral artery tortuosity index (VTI-h) using magnetic resonance or computed tomography angiography was calculated. Associations between VTI-h and outcomes of (1) cardiovascular events (arterial dissection/rupture, aneurysm requiring intervention, stroke), or (2) hollow organ collapse/rupture at age <50 years were evaluated using receiver operator curve analysis (using outcome by age 30 years) and mixed-effects Poisson regression for incidence rate ratios. Of 65 subjects (54% male), median VTI-h was 12 (interquartile range, 8-16). Variants were missense in 46%, splice site in 31%, and null/gene deletion in 14%. Thirty-two subjects (49%) had 59 events, including 28 dissections, 5 arterial ruptures, 4 aneurysms requiring intervention, 4 strokes, 11 hollow organ ruptures, and 7 pneumothoraces. Receiver operator curve analysis suggested optimal discrimination at VTI-h ≥15.5 for cardiovascular events (sensitivity 70%, specificity 76%) and no association with noncardiovascular events (area under the curve, 0.49 [95% CI, 0.22-0.78]). By multivariable analysis, older age was associated with increased cardiovascular event rate while VTI-h ≥15.5 was not (incidence rate ratios, 1.79 [95% CI, 0.76-4.24], P=0.185). However, VTI-h ≥15.5 was associated with events among those with high-risk variants <40 years (incidence rate ratios, 4.14 [95% CI, 1.13-15.10], P=0.032), suggesting effect modification by genotype and age. Conclusions Increased arterial tortuosity is associated with a higher incidence rate of cardiovascular events in Vascular Ehlers-Danlos syndrome. Vertebral tortuosity index may be a useful biomarker for prognosis when evaluated in conjunction with genotype and age.

Atypical infiltrates on endomyocardial biopsy are associated with adverse outcomes in pediatric heart transplantation.

BACKGROUND: The significance of atypical infiltrates (eosinophils or plasma cells) on endomyocardial biopsy (EMB) after pediatric heart transplant (HTx) is not known. We hypothesized that atypical infiltrates are associated with worse post-HTx outcomes. METHODS: We performed a retrospective cohort study of consecutive patients <21 years old who underwent primary HTx between 2013 and 2017. Multiorgan transplants were excluded. The presence of atypical infiltrates and burden of atypical infiltrates (rare vs predominant) on EMB were recorded. Primary outcome was a composite of cardiac allograft vasculopathy, graft failure (relisting or retransplant), or death. Presence of atypical infiltrates was evaluated: (1) overall using Cox regression with time-dependent covariates and (2) if present by 1 year post-HTx using Kaplan-Meier analysis. RESULTS: Atypical infiltrates were present in 24 out of 95 patients (25%) and were associated with a higher likelihood of reaching the composite outcome (hazard ratio (HR) 6.22, 95% confidence interval (CI) 2.60-14.89, p < 0.0001). This persisted when controlling for rejection in multivariable analysis. There was also a greater risk of the composite outcome if ≥2 nonconsecutive EMBs had atypical infiltrates (HR 11.80, 95%CI 3.17-43.84, p = 0.0002) or if atypical infiltrates were the predominant feature on EMB (HR 30.58, 95%CI 9.34-100.06, p < 0.0001). Patients with atypical infiltrates by 1-year post-HTx had a 5-year freedom from the composite outcome of 48%, compared to 90% if no atypical infiltrates had been present by this timepoint (log rank p = 0.002). CONCLUSIONS: The presence of atypical infiltrates on EMB is associated with significantly worse outcomes in children following HTx. These patients require closer follow-up to assess for developing graft dysfunction.

Abnormal Left Ventricular Strain Correlates with Left Ventricular Dysfunction but not Aortic Pathology in Marfan Syndrome in Children.

Cardiomyopathy is a complication in adults with Marfan syndrome (MFS). Early recognition of MFS patients at high risk of cardiomyopathy could impact monitoring and treatment. Abnormal ventricular strain has been associated with impaired ventricular function among adults with MFS but remains understudied in children. We retrospectively analyzed a cohort of patients with MFS undergoing cardiac magnetic resonance imaging (CMR) performed in 2003-2018 at age < 19 years. Correlations were evaluated between initial global circumferential strain (GCS) and global longitudinal strain (GLS) and the outcomes of left ventricular ejection fraction (LVEF), aortic root z-score, and vertebral artery tortuosity index corrected for height (VTI-h), all measured from CMR, using Spearman correlation. In those with serial CMR, the ability of ventricular strain to predict development of abnormal LVEF within a 5-year period was assessed. A total of 31 subjects were included (median age at initial CMR 13.5 years, Q1Q3 10.7-16.2 years), with 48% (n = 15) having LVEF < 55%. Worse GCS and worse GLS were associated with lower LVEF (ρ = - 0.629, p < 0.001 and ρ = - 0.411, p = 0.030, respectively). A clinical cutoff of GCS = - 34% predicted LVEF < 55% with sensitivity = 80% and specificity = 50%. Neither GCS nor GLS was associated with aortic root z-score (GCS: p = 0.524; GLS: p = 0.624) nor VTI-h (GCS: p = 0.949; GLS: p = 0.593). Of those with LVEF ≥ 55%, initial GCS and GLS did not differ between those with later normal versus abnormal LVEF (GCS: p = 0.505; GLS: p = 0.232). In this cohort, abnormal LV strain was associated with abnormal LVEF, but not with aortic dilation or low LVEF within the 5 years post-CMR.

Fetal Echocardiographic Z Score Pilot Project: Study Design and Impact of Gestational Age and Variable Type on Reproducibility of Measurements Within and Across Investigators.

BACKGROUND: Fetal echocardiography is widely available, but normative data are not robust. In this pilot study, the authors evaluated (1) the feasibility of prespecified measurements in a normal fetal echocardiogram to inform study design and (2) measurement variability to assign thresholds of clinical significance and guide analyses in larger fetal echocardiographic Z score initiatives. METHODS: Images from predefined gestational age groups (16-20, >20-24, >24-28, and >28-32 weeks) were retrospectively analyzed. Fetal echocardiography expert raters attended online group training and then independently analyzed 73 fetal studies (18 per age group) in a fully crossed design of 53 variables; each observer repeated measures for 12 fetuses. Kruskal-Wallis tests were used to compare measurements across centers and age groups. Coefficients of variation (CoVs) were calculated at the subject level for each measurement as the ratio of SD to mean. Intraclass correlation coefficients were used to show inter- and intrarater reliabilities. Cohen's d > 0.8 was used to define clinically important differences. Measurements were plotted against gestational age, biparietal diameter, and femur length. RESULTS: Expert raters completed each set of measurements in a mean of 23 ± 9 min/fetus. Missingness ranged from 0% to 29%. CoVs were similar across age groups for all variables (P < .05) except ductus arteriosus mean velocity and left ventricular ejection time, which were both higher at older gestational age. CoVs were >15% for right ventricular systolic and diastolic widths despite fair to good repeatability (intraclass correlation coefficient > 0.5); ductal velocities and two-dimensional measures, left ventricular short-axis dimensions, and isovolumic times all had high CoVs and high interobserver variability despite good to excellent intraobserver agreement (intraclass correlation coefficient > 0.6). CoVs did not improve when ratios (e.g., tricuspid/mitral annulus) were used instead of linear measurements. Overall, 27 variables had acceptable inter- and intraobserver repeatability, while 14 had excessive variability between readers despite good intraobserver agreement. CONCLUSIONS: There is considerable variability in fetal echocardiographic quantification in clinical practice that may affect the design of multicenter fetal echocardiographic Z score studies, and not all measurements may be feasible for standard normalization. As missingness was substantial, a prospective design will be needed. Data from this pilot study may aid in the calculation of sample sizes and inform thresholds for distinguishing clinically significant from statistically significant effects.

Thoracolumbar Scoliosis in Pediatric Patients With Loeys-Dietz Syndrome: A Case Series.

Background Loeys-Dietz syndrome (LDS) is a genetic connective tissue disorder that predominantly affects cardiovascular, skeletal, and craniofacial structures. Associated thoracolumbar scoliosis in LDS can be challenging to manage, though other etiologies of pediatric scoliosis have better-defined management guidelines. We examined our institutional experience regarding the treatment of pediatric patients with LDS and scoliosis. Methodology In this retrospective study, all patients seen at our pediatric tertiary care center from 2004 through 2018 with a diagnosis of LDS were reviewed, and those with radiographic diagnoses of scoliosis (full-length scoliosis X-rays) were included. Demographic, clinical, and radiographic parameters were collected, and management strategies were reported. Results A total of 39 LDS patients whose ages ranged between seven and 13 years were identified. A total of nine patients were radiographically diagnosed with scoliosis, but three patients were excluded due to incomplete medical records, leaving six patients. The median age at scoliosis diagnosis was 11.5 years, with a median follow-up of 51 months. Two patients were successfully managed with observation (average initial Cobb angle (CA): 14°, average final CA: 20.5°). Two were braced, one successfully (initial CA: 15°, final CA: 30°) and one with a progressive disease requiring surgery (initial CA: 40°, final CA: 58°). Of the two who were offered surgical correction, one underwent surgery with a durable correction of spinal deformity (CA: 33° to 19°). One patient underwent a recent correction of aortic root dilatation and was not a candidate for scoliosis surgery. Conclusions Principles of adolescent idiopathic scoliosis management such as bracing for CA of 20-50° and surgery for CA of >50° can be applied to LDS patients with good outcomes. This augments our understanding of the treatment algorithm for pediatric patients with LDS.