Relationship of Echocardiographic Z Scores Adjusted for Body Surface Area to Age, Sex, Race, and Ethnicity: The Pediatric Heart Network Normal Echocardiogram Database

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.

Limited Relationship Between Echocardiographic Measures and Electrocardiographic Markers of Left Ventricular Size in Healthy Children

Pediatric ECG standards have been defined without echocardiographic confirmation of normal anatomy. The Pediatric Heart Network Normal Echocardiogram Z-score Project provides a racially diverse group of healthy children with normal echocardiograms. We hypothesized that ECG and echocardiographic measures of left ventricular (LV) dimensions are sufficiently correlated in healthy children to imply a clinically meaningful relationship. This was a secondary analysis of a previously described cohort including 2170 digital ECGs. The relationship between 6 ECG measures associated with LV size were analyzed with LV Mass (LVMass-z) and left ventricular end-diastolic volume (LVEDV-z) along with 11 additional parameters. Pearson or Spearman correlations were calculated for the 78 ECG-echocardiographic pairs with regression analyses assessing the variance in ECG measures explained by variation in LV dimensions and demographic variables. ECG/echocardiographic measurement correlations were significant and concordant in 41/78 (53%), though many were significant and discordant (13/78). Of the 6 ECG parameters, 5 correlated in the clinically predicted direction for LV Mass-z and LVEDV-z. Even when statistically significant, correlations were weak (0.05-0.24). R2 was higher for demographic variables than for echocardiographic measures or body surface area in all pairs, but remained weak (R2 ≤ 0.17). In a large cohort of healthy children, there was a positive association between echocardiographic measures of LV size and ECG measures of LVH. These correlations were weak and dependent on factors other than echocardiographic or patient derived variables. Thus, our data support deemphasizing the use of solitary, traditional measurement-based ECG markers traditionally thought to be characteristic of LVH as standalone indications for further cardiac evaluation of LVH in children and adolescents.

Enhanced aortic stiffness in adolescents with chronic disease is associated with decreased left ventricular global longitudinal strain

Background

The recent Cardiovascular Disease in Adolescents with Chronic Disease (CDACD) study showed enhanced aortic stiffness and wall thickness in adolescents with various chronic disorders. Enhanced aortic stiffness can increase left ventricular (LV) afterload and trigger a cascade of adverse arterioventricular interaction. Here, we investigate the relation between aortic changes and LV function in the CDACD study participants.

Methods

This cross-sectional study included 114 adolescents 12-18 years old with cystic fibrosis (CF, n = 24), corrected coarctation of the aorta (CoA, n = 25), juvenile idiopathic arthritis (JIA, n = 20), obesity (n = 20), and healthy controls (n = 25). Aortic pulse wave velocity (PWV), which reflects aortic stiffness, and aortic wall thickness (AWT) were assessed with cardiovascular magnetic resonance imaging (CMR). Echocardiography was employed to study conventional markers of LV function, as well as LV global longitudinal strain (LVGLS), which is an established (pre)clinical marker of LV dysfunction.

Results

First, aortic PWV and AWT were increased in all chronic disease groups, compared to controls. Second, in adolescents with CoA, JIA, and obesity, echocardiography showed a decreased LVGLS, while LV dimensions and conventional LV function markers were similar to controls. Third, multivariable linear regression identified aortic PWV as the most important determinant of their decreased LVGLS (standardized β -0.522, p < 0.001).

Conclusions

The decreased LVGLS in several adolescent chronic disease groups was associated with enhanced aortic PWV, which might reflect adverse arterioventricular interaction. Whether the decreased LVGLS in the chronic disease groups could negatively impact their long-term cardiovascular outcomes requires further study.

Outcomes of Neonates Born with Symptomatic Tetralogy of Fallot and Absent Ductus Arteriosus

OBJECTIVE

To test the hypothesis that neonates with symptomatic tetralogy of Fallot (TOF) and absent ductus arteriosus (ADA) have worse clinical outcomes compared with those with a ductus arteriosus (DA), and that this difference is driven by those born with ADA and with critically deficient pulmonary blood flow (CDPBF).

STUDY DESIGN

We performed a retrospective, multicenter cohort study of neonates who underwent intervention for symptomatic TOF comparing death and reintervention between subjects with and without a DA identified on fetal echocardiogram or on echocardiogram performed in the first postnatal day. Exclusion criteria were as follows: inability to define DA status, collaterals supplying pulmonary blood flow, atrioventricular septal defect, and absent pulmonary valve. We defined CDPBF as undergoing a procedure to augment pulmonary blood flow on the date of birth or extracorporeal membrane oxygenation prior to such a procedure.

RESULTS

The study cohort included 519 patients, among whom 11% had ADA. Patients with ADA were more likely to have a genetic syndrome and had smaller branch pulmonary artery size. In analyses adjusting for center, interventional treatment strategy, genetic syndrome, and minimum branch pulmonary artery size, ADA was associated with higher mortality risk (adjusted hazard ratio of 2.37 (95% CI: 1.07,5.27; P = .034). Seven patients had CDPBF (1.3% of the entire cohort and 12% of patients with ADA).

CONCLUSIONS

A minority of symptomatic TOF neonates have ADA, which is associated with higher adjusted mortality risk compared with those with a DA. CDPBF appears to be a rare but important entity in this population.

Normative Computed Tomography Angiography Values of the Aortic Root, Aorta and Aortic arch in Children

Purpose

Normative values for intracardiac and extracardiac vascular structures help in understanding normal growth and changes over time in children; this normative data are not currently available for ECG-gated Computed Tomography Angiography (CTA). We sought to establish ECG-gated CTA derived normative values for the aortic root, aorta and aortic arch in children.

Methods and Results

Aortic root, ascending aorta, aortic arch, and descending aorta were measured in systole and diastole in 100 subjects who had ECG-gated CTA at our center between January 2015 through December 2020 and met our inclusion criteria. The allometric exponent (AE) for each parameter was derived, and the parameter/body surface areaAE (BSAAE) was established using the previously described methods. Using this data, normalized mean, cross-sectional area, and standard deviation were calculated. Z-score curves were plotted in relation to the BSA for all measurements.

Conclusion

Our study reports systolic and diastolic ECG-gated CTA Z-scores along with normative curves in relation to BSA for the aortic root, aorta and aortic arch in children.

Comprehensive Two-Dimensional Pediatric Echocardiographic Nomograms for Coronary Artery Sizes in Caucasian Children and Comparison among Major Nomograms

BACKGROUND

Although coronary artery nomograms in children have been published, data on Caucasian children are lacking. The aim of this study is to provide: (i) a full dataset of coronary artery diameters in healthy children and (ii) a comparison among major previous nomograms.

MATERIALS AND METHODS

We prospectively evaluated 606 healthy subjects (age range, 1 days-<18 years; median age 8.7 years; 62.5% male). Coronary artery measurements in a short-axis view were performed. Age, heart rate, and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement. To assess the accuracy of the predictive models of different studies, a Z-score calculator was created using Lopez's nomograms for comparison.

RESULTS

The association with BSA was found to be stronger, and was used for normalization of our data. The best-fit models, satisfying the assumption of homoscedasticity and normality of residuals and showing the highest R2 scores, were logarithmic (ln[y] = a + b*ln[x]). Predicted values and Z-score boundaries by BSA are provided. Our ranges of normality are slightly lower than those, diverging from -0.22 to -0.59 Z-scores for the left main coronary artery and from -0.23 to -0.3 Z-scores for the right coronary artery.

CONCLUSIONS

We report a complete dataset of normal echocardiography coronary artery diameter (including new measures of the proximal origin) values in a large population of healthy children. Our data were statistically like those of north American nomograms.

Aortic Dilatation in Children and Young People With ADPKD

Introduction

Aortic root dilatation is a reported cardiovascular sequela seen in children and young people (CYP) with chronic kidney disease (CKD) but has yet to be described in those with autosomal dominant polycystic kidney disease (ADPKD).

Methods

Single center, cross-sectional study in a dedicated ADPKD clinic. Echocardiograms were evaluated for the presence of dilatation (defined by a z-score ≥2 [≥99th percentile] SDs from the mean) at 4 standardized locations, namely the aortic valve annulus, sinuses of Valsalva (SoV), sinotubular junction (STJ), and the ascending aorta. Measurements were compared with a control group to assess prevalence, severity, and determinants of aortic dilatation.

Results

Ninety-seven children, median age (interquartile range) of 9.3 (6.1, 13.6) years were compared with 19 controls without ADPKD or other CKD. The prevalence of dilatation ranged from 5.2% to 17% in ADPKD, depending on anatomical location with no aortic dilatation identified in the control group. In multivariable regression, aortic root dilatation was significantly associated with cyst burden at the aortic valve annulus and SoV (β = 0.42 and β = 0.39, both P < 0.001), with age at SoV (β = -0.26, P = 0.02), systolic blood pressure (SBP) z-score at SoV (β = -0.20, P = 0.04) and left ventricular mass index (LVMI) at SoV and STJ (β = 0.24, P = 0.02 and β = 0.25, P = 0.03, respectively) following adjustment for age, sex (male or female), body mass index (BMI) z-score, estimated glomerular filtration rate (eGFR), SBP z-score, and LVMI.

Conclusion

Our data suggests increased prevalence of aortic root and ascending aortic dilatation in CYP with ADPKD compared with controls. Further studies are needed to understand the pathogenesis and its contribution to the high cardiovascular morbidity in ADPKD.

Discordance interpretation of left ventricular size between echocardiography and cardiac magnetic resonance in pediatric patients with aortic/mitral regurgitation

PURPOSE

This study investigated discordance between echocardiography (echo) and cardiac magnetic resonance (CMR) measurements of the left ventricle (LV) in pediatric patients with aortic and/or mitral regurgitation (AR/MR).

METHODS

Retrospective cohort study of pediatric patients. The cohorts were comprised of patients with AR/MR vs. non-AR/MR. Left ventricular end diastolic volume (LVEDV) by CMR and left ventricular internal diameter diastolic (LVIDd) by echo were obtained from clinical reports then echo images were reviewed to remeasure LVEDV by bullet method. Left ventricular internal diameter systolic (LVIDs) and left ventricular ejection fraction (LVEF) measurements by echo and LVEF by CMR were obtained from clinical reports. Fractional shortening (FS%) was recalculated. Z-scores were calculated using normative data. Correlation between echo and CMR LV measurements was assessed using correlation coefficients. Bland-Altman plots assessed bias between imaging modalities. Receiver operator characteristic (ROC) analysis was performed for detection of LV enlargement and LV dysfunction.

RESULTS

AR/MR patients had greater discrepancy in LV size interpretation by Z-score compared to non-AR/MR patients. This discrepancy persisted when the bullet method short axis measurements were incorporated. There was negative bias in echo-based measurements compared to CMR. The diagnostic performance of echo in identifying moderate LV enlargement was worse for AR/MR pediatrics patients.

CONCLUSION

The discordant interpretation of LV size by echo compared to CMR is worse in pediatric patients with AR/MR when compared to patients without AR/MR even when short axis measurements are incorporated. This finding suggests non-uniform geometrical changes in the LV as it enlarges due to AR/MR.

Late Outcomes of Konno-Rastan and Modified Konno for Left Ventricular Outflow Tract Obstruction

BACKGROUND

While early outcomes of the Konno-Rastan and modified Konno procedures are known, long-term outcomes remain undetermined. Our objective was to examine long-term clinical and echocardiographic outcomes.

METHODS

Retrospective review was performed of patients undergoing Konno-Rastan and modified Konno for complex left ventricular outflow tract (LVOT) obstruction from January 1980 to January 2021. The Ross-Konno procedure was excluded due to its often limited ventriculotomy.

RESULTS

A total of 92 patients were identified: 73 Konno-Rastan and 19 modified Konno. The modified Konno group was significantly younger (median [interquartile range, IQR]: 6, [2-12] years vs 16 [9-32] years, P = .001). LVOT obstruction was multilevel (39 of 92 [42.4%]), tunnel subaortic (35 of 92 [38.0%]), or aortic valve stenosis/annular hypoplasia (18 of 92 [19.6%]). Shone syndrome was present in 20 of 92 (21.7%) patients. Operative mortality was 7 of 92 (7.6%); 4 of 86 (4.7%) in elective vs 3 of 6 (50.0%) in urgent cases (P = .005). Median follow-up was 12 (IQR, 5-22) years. Aortic valve/LVOT mean gradient was 13 (IQR, 10-18) mm Hg at 1 year but gradually increased to 25 (IQR, 13-46) mm Hg at 10 years. Ejection fraction remained normal. Freedom from reoperation at 5 and 10 years was 77.2% and 58.4% among Konno-Rastan and 57.7% and 41.7% among modified Konno patients (P = .28), respectively. Overall survival at 5, 10, and 15 years was 82.9%, 76.3%, and 65.5%. Risk factors for mortality included older age, New York Heart Association class III/IV, longer cardiopulmonary bypass time, and multilevel LVOT obstruction.

CONCLUSIONS

While LVOT obstruction is alleviated early, recurrent LVOT obstruction occurs over time after Konno-Rastan and modified Konno procedures. Additionally, despite preserved left ventricular systolic function, late overall survival is poor in this young population.

Adaptation of Left Ventricular Twist Mechanics in Exercise-Trained Children Is Only Evident after the Adolescent Growth Spurt

BACKGROUND

The extent of structural cardiac remodeling in response to endurance training is maturity dependent. In adults, this structural adaptation is often associated with the adaptation of left ventricular (LV) twist mechanics. For example, an increase in LV twist often follows an expansion in end-diastolic volume, whereas a reduction in twist may follow a thickening of the LV walls. While structural cardiac remodeling has been shown to be more prominent post-peak height velocity (PHV), it remains to be determined how this maturation-dependent structural remodeling influences LV twist. Therefore, we aimed to (1) compare LV twist mechanics between trained and untrained children pre- and post-PHV and (2) investigate how LV structural variables relate to LV twist mechanics pre- and post-PHV.

METHODS

Left ventricular function and morphology were assessed (echocardiography) in endurance-trained and untrained boys (n = 38 and n = 28, respectively) and girls (n = 39 and n = 34, respectively). Participants were categorized as either pre- or post-PHV using maturity offset to estimate somatic maturation.

RESULTS

Pre-PHV, there were no differences in LV twist or torsion between trained and untrained boys (twist: P = .630; torsion: P = .382) or girls (twist: P = .502; torsion: P = .316), and LV twist mechanics were not related with any LV structural variables (P > .05). Post-PHV, LV twist was lower in trained versus untrained boys (P = .004), with torsion lower in trained groups, irrespective of sex (boys: P < .001; girls: P = .017). Moreover, LV torsion was inversely related to LV mass (boys: r = -0.55, P = .001; girls: r = -0.46, P = .003) and end-diastolic volume (boys: r = -0.64, P < .001; girls: r = -0.36, P = .025) in both sexes.

CONCLUSIONS

A difference in LV twist mechanics between endurance-trained and untrained cohorts is only apparent post-PHV, where structural and functional remodeling were related.

Newly Developed Sex-Specific Z Score Model for Coronary Artery Diameter in a Pediatric Population

BACKGROUND

This study aimed to generate a Z score calculation model for coronary artery diameter of normal children and adolescents to be adopted as the standard calculation method with consensus in clinical practice.

METHODS

This study was a retrospective, multicenter study that collected data from multiple institutions across South Korea. Data were analyzed to determine the model that best fit the relationship between the diameter of coronary arteries and independent demographic parameters. Linear, power, logarithmic, exponential, and square root polynomial models were tested for best fit.

RESULTS

Data of 2,030 subjects were collected from 16 institutions. Separate calculation models for each sex were developed because the impact of demographic variables on the diameter of coronary arteries differs according to sex. The final model was the polynomial formula with an exponential relationship between the diameter of coronary arteries and body surface area using the DuBois formula.

CONCLUSION

A new coronary artery diameter Z score model was developed and is anticipated to be applicable in clinical practice. The new model will help establish a consensus-based Z score model.

Impact of right ventriculotomy on cardiac function after pulmonary valve sparing repair of tetralogy of Fallot and double outlet right ventricle with pulmonary stenosis

OBJECTIVES

Pulmonary valve-sparing repair of tetralogy of Fallot and double outlet right ventricle with pulmonary stenosis has the advantage of reduced incidence of late pulmonary valve regurgitation and better-preserved cardiac function. However, a right ventriculotomy is sometimes necessary in order to adequately relieve subvalvular pulmonary stenosis. We aimed to compare postoperative cardiac function and patients' symptoms between pulmonary valve-sparing repair with and without right ventriculotomy.

MATERIALS AND METHODS

We retrospectively collected data from electronic medical records of Ramathibodi Hospital from 1st January 2013 to 31st October 2023. Patients diagnosed with tetralogy of Fallot and double outlet right ventricle with pulmonary stenosis who underwent pulmonary valve-sparing repair were included. Patients who underwent other types of repairs and whose medical record data were significantly missing were excluded. Demographic data, operative, and postoperative details were collected and reviewed.

RESULTS

There were 49 patients included in our study with 10 patients undergoing pulmonary valve-sparing repair with and the other 39 without right ventriculotomy. Before-discharge echocardiographic parameters were generally similar between both groups (tricuspid annular plane systolic excursion = 0.9 versus 0.89 cm, P = 0.737; pressure gradient across pulmonary valve across pulmonary valve = 24 versus 19 mmHg, P = 0.275; left ventricular end-systolic volume index = 17.84 versus 19.19 ml/m2, P = 0.437; left ventricular end-diastolic volume index = 63.79 versus 61.13 ml/m2, P = 0.436). Patients' symptoms were also not statistically different. There was no early and late death up to the end date of our study.

CONCLUSIONS

Right ventriculotomy in pulmonary valve-sparing repair did not result in worse postoperative cardiac function and symptoms. This suggested that the previously thought-to-be hazardous incision could be strongly considered if mandated.

Unique Features of Cardiovascular Involvement and Progression in Children with Marfan Syndrome Justify Dedicated Multidisciplinary Care

Marfan syndrome (MIM: # 154700; MFS) is an autosomal dominant disease representing the most common form of heritable connective tissue disorder. The condition presents variable multiorgan expression, typically involving a triad of cardiovascular, eye, and skeletal manifestations. Other multisystemic features are often underdiagnosed. Moreover, the disease is characterized by age related penetrance. Diagnosis and management of MFS in the adult population are well-described in literature. Few studies are focused on MFS in the pediatric population, making the clinical approach (cardiac and multiorgan) to these cases challenging both in terms of diagnosis and serial follow-up. In this review, we provide an overview of MFS manifestations in children, with extensive revision of major organ involvement (cardiovascular ocular and skeletal). We attempt to shed light on minor aspects of MFS that can have a significant progressive impact on the health of affected children. MFS is an example of a syndrome where an early personalized approach to address a dynamic, genetically determined condition can make a difference in outcome. Applying an early multidisciplinary clinical approach to MFS cases can prevent acute and chronic complications, offer tailored management, and improve the quality of life of patients.

Estimation of z-scores of cardiac structures in healthy children in Southeast Nigeria

BACKGROUND

The z-scoring system shows the mean deviation of cardiac dimensions from age-specific population. The use of the European-based z-score studies has resulted in misdiagnosis and late treatment of Nigerian children with heart diseases leading to increased mortality and morbidity.

OBJECTIVES

This study aimed to determine the z‑scores for various cardiac structures and functions among healthy children in Southeast Nigeria.

MATERIALS AND METHODS

This is a cross-sectional observational study where z-scores of the cardiac structure and function of three hundred healthy children were estimated using echocardiography and compared with the standard Detroit values.

RESULT

There was a significant positive correlation between age and cardiac valve diameter. The aortic valve strongly correlated positively with age with the Pearson correlation coefficient (ρ) of 0.8 and probability value (P-value) of 0.00. None of the ventricular function variables deviated beyond the +2 or -2 z-score. There was a positive correlation between the z-scores of ventricular function parameters and participants' age, although the strength of the correlation varied. Comparing these values with that of Detroit values, there was a significant difference in the deviation of the mean of the mitral valve and left pulmonary artery diameters from the Detroit values between the males and the females. While the mean z-score mitral valve was 0.8 in males, it was 0.6 in females (P = 0.02).

CONCLUSION

Z-scores of cardiac structures and function are derived from children in this locale. These values were similar to that of Detroit values except for the mitral valve and left pulmonary artery.

2023 World Heart Federation guidelines for the echocardiographic diagnosis of rheumatic heart disease

Rheumatic heart disease (RHD) is an important and preventable cause of morbidity and mortality among children and young adults in low-income and middle-income countries, as well as among certain at-risk populations living in high-income countries. The 2012 World Heart Federation echocardiographic criteria provided a standardized approach for the identification of RHD and facilitated an improvement in early case detection. The 2012 criteria were used to define disease burden in numerous epidemiological studies, but researchers and clinicians have since highlighted limitations that have prompted a revision. In this updated version of the guidelines, we incorporate evidence from a scoping review, an expert panel and end-user feedback and present an approach for active case finding for RHD, including the use of screening and confirmatory criteria. These guidelines also introduce a new stage-based classification for RHD to identify the risk of disease progression. They describe the latest evidence and recommendations on population-based echocardiographic active case finding and risk stratification. Secondary antibiotic prophylaxis, echocardiography equipment and task sharing for RHD active case finding are also discussed. These World Heart Federation 2023 guidelines provide a concise and updated resource for clinical and research applications in RHD-endemic regions.

Natural history and outcomes in paediatric RASopathy-associated hypertrophic cardiomyopathy

AIMS

This study aimed to describe the natural history and predictors of all-cause mortality and sudden cardiac death (SCD)/equivalent events in children with a RASopathy syndrome and hypertrophic cardiomyopathy (HCM).

METHODS AND RESULTS

This is a retrospective cohort study from 14 paediatric cardiology centres in the United Kingdom and Ireland. We included children <18 years with HCM and a clinical and/or genetic diagnosis of a RASopathy syndrome [Noonan syndrome (NS), NS with multiple lentigines (NSML), Costello syndrome (CS), cardiofaciocutaneous syndrome (CFCS), and NS with loose anagen hair (NS-LAH)]. One hundred forty-nine patients were recruited [111 (74.5%) NS, 12 (8.05%) NSML, 6 (4.03%) CS, 6 (4.03%) CFCS, 11 (7.4%) Noonan-like syndrome, and 3 (2%) NS-LAH]. NSML patients had higher left ventricular outflow tract (LVOT) gradient values [60 (36-80) mmHg, P = 0.004]. Over a median follow-up of 197.5 [inter-quartile range (IQR) 93.58-370] months, 23 patients (15.43%) died at a median age of 24.1 (IQR 5.6-175.9) months. Survival was 96.45% [95% confidence interval (CI) 91.69-98.51], 90.42% (95% CI 84.04-94.33), and 84.12% (95% CI 75.42-89.94) at 1, 5, and 10 years, respectively, but this varied by RASopathy syndrome. RASopathy syndrome, symptoms at baseline, congestive cardiac failure (CCF), non-sustained ventricular tachycardia (NSVT), and maximal left ventricular wall thickness were identified as predictors of all-cause mortality on univariate analysis, and CCF, NSVT, and LVOT gradient were predictors for SCD or equivalent event.

CONCLUSIONS

These findings highlight a distinct category of patients with Noonan-like syndrome with a milder HCM phenotype but significantly worse survival and identify potential predictors of adverse outcome in patients with RASopathy-related HCM.

Virtual Planning and Patient-Specific Graft Design for Aortic Repairs

PURPOSE

Patients presenting with coarctation of the aorta (CoA) may also suffer from co-existing transverse arch hypoplasia (TAH). Depending on the risks associated with the surgery and the severity of TAH, clinicians may decide to repair only CoA, and monitor the TAH to see if it improves as the patient grows. While acutely successful, eventually hemodynamics may become suboptimal if TAH is left untreated. The objective of this work aims to develop a patient-specific surgical planning framework for predicting and assessing postoperative outcomes of simple CoA repair and comprehensive repair of CoA and TAH.

METHODS

The surgical planning framework consisted of virtual clamp placement, stenosis resection, and design and optimization of patient-specific aortic grafts that involved geometrical modeling of the graft and computational fluid dynamics (CFD) simulation for evaluating various surgical plans. Time-dependent CFD simulations were performed using Windkessel boundary conditions at the outlets that were obtained from patient-specific non-invasive pressure and flow data to predict hemodynamics before and after the virtual repairs. We applied the proposed framework to investigate optimal repairs for six patients (n = 6) diagnosed with both CoA and TAH. Design optimization was performed by creating a combination of a tubular graft and a waterslide patch to reconstruct the aortic arch. The surfaces of the designed graft were parameterized to optimize the shape.

RESULTS

Peak systolic pressure drop (PSPD) and time-averaged wall shear stress (TAWSS) were used as performance metrics to evaluate surgical outcomes of various graft designs and implantation. The average PSPD improvements were 28% and 44% after the isolated CoA repair and comprehensive repair, respectively. Maximum values of TAWSS were decreased by 60% after CoA repair and further improved by 22% after the comprehensive repair. The oscillatory shear index was calculated and the values were confirmed to be in the normal range after the repairs.

CONCLUSION

The results showed that the comprehensive repair outperforms the simple CoA repair and may be more advantageous in the long term in some patients. We demonstrated that the surgical planning and patient-specific flow simulations could potentially affect the selection and outcomes of aorta repairs.

Impact of Genotype-Phenotype Interactions on Cardiovascular Function in Paediatric Loeys-Dietz Syndrome

Background

The relationship between genotype and phenotypical vascular and cardiac properties in paediatric Loeys-Dietz syndrome (LDS) patients are not well characterized. This study explores the phenotypical differences in aortic properties and cardiac structural and functional parameters between paediatric LDS patients with TGFBR1 and TGFBR2 mutations.

Methods

We included 32 LDS patients with either TGFBR1 (n = 17) or TGFBR2 (n = 15) mutations. Echocardiographic data included aortic dimensions, distensibility, strain, and stiffness at the level of the annulus, sinuses of Valsalva, sinotubular junction, ascending aorta, and descending aorta. Parameters for left ventricular size and function were also recorded.

Results

Demographics were similar between the groups. Patients with TGFBR2 were more likely to have undergone aortic surgery (47% vs 12%, P = 0.057) and use angiotensin receptor blockers (93% vs 47%, P = 0.015). Aortic z scores were significantly larger in the TGFBR2 group at the level of the aortic valve annulus (P = 0.007), sinuses of Valsalva (P = 0.001), sinotubular junction (P = 0.001), and ascending aorta (P = 0.054). Patients with TGFBR2 also had significantly lower aortic distensibility and strain coupled with higher stiffness index at the level of the annulus, sinotubular junction, and ascending aorta. Parameters for the descending aorta, cardiac morphology, and cardiac function were similar between the groups.

Conclusions

Paediatric LDS patients with TGFBR2 present with more severe cardiovascular phenotypes than patients with TGFBR1 with larger aortic dimensions and increased aortic stiffness. Our findings suggest that genotypes should be taken into consideration in the clinical management of paediatric LDS patients.

Longitudinal ECG changes in tetralogy of Fallot and association with surgical repair

Background

ECG abnormalities have been linked to adverse changes in right ventricular (RV) morphology and poor clinical outcomes in repaired Tetralogy of Fallot (rTOF). Our aim was to describe how ECG changes progress in early and intermediate follow-up and whether types of surgical strategy at the time of primary repair affected these changes.

Methods

We studied patients with rTOF born 2000-2018 operated at our institution. Seven time points in relation to primary repair, follow-up, and pulmonary valve replacement (PVR) were identified. Patients correct with valve sparing repair (VSR), trans-annular patch (TAP) including with a monocusp valve (TAP + M) and with at least 3 ECGs were included. PQ interval, QRS duration, dispersion, and fragmentation, QTc duration and dispersion, JTc as well as presence of a right bundle branch block (RBBB) were analyzed. Medical records were reviewed for demographic and surgical data.

Results

Two hundred nineteen patients with 882 ECGs were analyzed with a median follow-up time of 12.3 years (8.4, 17) with 41 (19%) needing PVR during the study period. QRS duration increased at time of primary repair to discharge from 66 msec (IQR 12) to 129 msec (IQR 27) (p < 0.0001) and at 1- and 6- year follow-up but showed only a modest and temporary decrease after PVR. QTc increased at the time of primary repair as well as prior to PVR. PQ interval showed a small increase at the time of primary repair, was at its highest prior to PVR and decreased with PVR. Type of surgical repair affected mainly QTc and JTc and was consistently longer in the TAP + M group until PVR. In VSR, QTc and JTc were prolonged initially compared to TAP but were similar after 1 year. After PVR, there were no differences in adverse ECG changes between surgical groups.

Conclusions

PQ interval and QRS duration best correspond to the assumed volume load whereas the relationship with QTc and JTc is more complex, suggesting that these represent more complex remodeling of the myocardium. Before PVR, QTc and JTc are longer in the TAP + M group which may be due to a longer surgical incision.

Distinguishing left ventricular hypertrophy from hypertrophic cardiomyopathy in adolescents: a longitudinal observation study

AIMS

Echocardiographic characteristics to distinguish physiological left ventricular (LV) hypertrophy from pathology are warranted in early adolescent athletes. This study aimed to explore the phenotype, progression, and potential grey zone of LV hypertrophy during adolescence in athletes and hypertrophic cardiomyopathy (HCM) genotype-positive patients.

METHODS AND RESULTS

In this longitudinal observation study, we compared seventy-six 12-year-old athletes with 55 age-matched and sex-matched HCM genotype-positive patients. Echocardiographic parameters were evaluated by using paediatric reference values (Z-scores). Hypertrophic cardiomyopathy genotype-positive patients were included if they had no or mild LV hypertrophy [maximum wall thickness <13 mm, Z-score <6 for interventricular septum diameter (ZIVSd), or posterior wall thickness]. We collected clinical data, including data on cardiac events. The mean follow-up-time was 3.2 ± 0.8 years. At baseline, LV hypertrophy was found in 28% of athletes and 21% of HCM genotype-positive patients (P = 0.42). Septum thickness values were similar (ZIVSd 1.4 ± 0.9 vs. 1.0 ± 1.3, P = 0.08) and increased only in HCM genotype-positive patients {ZIVSd progression rate -0.17 [standard error (SE) 0.05], P = 0.002 vs. 0.30 [SE 0.10], P = 0.001}. Left ventricular volume Z-scores (ZLVEDV) were greater in athletes [ZLVEDV 1.0 ± 0.6 vs. -0.1 ± 0.8, P < 0.001; ZLVEDV progression rate -0.05 (SE 0.04), P = 0.21 vs. -0.06 (SE 0.04), P = 0.12]. Cardiac arrest occurred in two HCM genotype-positive patients (ages 13 and 14), with ZIVSd 8.2-11.5.

CONCLUSION

Left ventricular hypertrophy was found in a similar proportion in early adolescence but progressed only in HCM genotype-positive patients. A potential grey zone of LV hypertrophy ranged from a septum thickness Z-score of 2.0 to 3.3. Left ventricular volumes remained larger in athletes. Evaluating the progression of wall thickness and volume may help clinicians distinguish physiological LV hypertrophy from early HCM.

Pediatric ECG-Based Deep Learning to Predict Left Ventricular Dysfunction and Remodeling

BACKGROUND

Artificial intelligence-enhanced ECG analysis shows promise to detect ventricular dysfunction and remodeling in adult populations. However, its application to pediatric populations remains underexplored.

METHODS

A convolutional neural network was trained on paired ECG-echocardiograms (≤2 days apart) from patients ≤18 years of age without major congenital heart disease to detect human expert-classified greater than mild left ventricular (LV) dysfunction, hypertrophy, and dilation (individually and as a composite outcome). Model performance was evaluated on single ECG-echocardiogram pairs per patient at Boston Children's Hospital and externally at Mount Sinai Hospital using area under the receiver operating characteristic curve (AUROC) and area under the precision-recall curve (AUPRC).

RESULTS

The training cohort comprised 92 377 ECG-echocardiogram pairs (46 261 patients; median age, 8.2 years). Test groups included internal testing (12 631 patients; median age, 8.8 years; 4.6% composite outcomes), emergency department (2830 patients; median age, 7.7 years; 10.0% composite outcomes), and external validation (5088 patients; median age, 4.3 years; 6.1% composite outcomes) cohorts. Model performance was similar on internal test and emergency department cohorts, with model predictions of LV hypertrophy outperforming the pediatric cardiologist expert benchmark. Adding age and sex to the model added no benefit to model performance. When using quantitative outcome cutoffs, model performance was similar between internal testing (composite outcome: AUROC, 0.88, AUPRC, 0.43; LV dysfunction: AUROC, 0.92, AUPRC, 0.23; LV hypertrophy: AUROC, 0.88, AUPRC, 0.28; LV dilation: AUROC, 0.91, AUPRC, 0.47) and external validation (composite outcome: AUROC, 0.86, AUPRC, 0.39; LV dysfunction: AUROC, 0.94, AUPRC, 0.32; LV hypertrophy: AUROC, 0.84, AUPRC, 0.25; LV dilation: AUROC, 0.87, AUPRC, 0.33), with composite outcome negative predictive values of 99.0% and 99.2%, respectively. Saliency mapping highlighted ECG components that influenced model predictions (precordial QRS complexes for all outcomes; T waves for LV dysfunction). High-risk ECG features include lateral T-wave inversion (LV dysfunction), deep S waves in V1 and V2 and tall R waves in V6 (LV hypertrophy), and tall R waves in V4 through V6 (LV dilation).

CONCLUSIONS

This externally validated algorithm shows promise to inexpensively screen for LV dysfunction and remodeling in children, which may facilitate improved access to care by democratizing the expertise of pediatric cardiologists.

Perioperative and Anesthetic Considerations in Shone's Complex

Shone's complex is a congenital cardiac disease consisting of the following four lesions: parachute mitral valve, supravalvar mitral ring, subaortic stenosis, and aortic coarctation. Though not all components are required for a diagnosis, the end result is both left ventricular inflow and outflow obstruction, which typically present in patients as congestive heart failure. The complex pathology requires careful management and surgical decision-making to ensure an optimal outcome. This review will focus on the anatomy, physiology, and perioperative anesthetic management of patients with Shone's complex.

Echogenomics: Echocardiography in Heritable Aortopathies

PURPOSE OF REVIEW

The aim of this article is to review the current echocardiographic considerations in the diagnosis and monitoring of patients with inherited aortopathies.

RECENT FINDINGS

Aortic dilation is a key feature in heritable aortopathies, and dissection is a leading cause of morbidity and mortality. New genetic and histopathologic findings are helpful in better understanding these conditions. Non-invasive imaging modalities, including echocardiogram, computerized tomography, and magnetic resonance imaging, are essential in monitoring these patients, as well as providing new prognostic factors of arterial stiffness that may help with risk stratification in the future. Diagnosis of heritable aortopathies should be considered with identification of aortic root dilation, particularly in children and young adults, or when there is a family history of aortic disease. Recent adult consensus guidelines highlight the importance of underlying genotype and phenotypic features when considering prophylactic surgical intervention. There are currently no consensus pediatric guidelines.

Normative computed tomography angiography values of the main and branch pulmonary arteries in children

Non-invasive cardiac imaging like echocardiogram, cardiac magnetic resonance imaging (CMR), and computed tomography angiography (CTA) play a key role in the diagnosis, aid in management and follow-up of congenital heart disease patients. Normative data for intracardiac and extracardiac vascular structures in children are currently available for echocardiogram, CMR, and non-gated CTA. We sought to establish systolic and diastolic normative data for main and branch pulmonary arteries in children using electrocardiogram (ECG)-gated CTA. Diameters and cross-sectional areas of the main and branch pulmonary arteries were measured in systole and diastole based on the aortic valve position (open versus closed) in 100 subjects who had ECG-gated cardiac CTA at our center between January 2015 through December 2020 and met our inclusion criteria. The allometric exponent (AE) for each parameter was derived, and the parameter/body surface area (BSAAE) was established using the previously described methods. A total of 100 children aged 0-18 years were analyzed; mean age was 5.3 years (SD, 6.1 years). Z-score curves were plotted in relation to the BSA for the mean, maximum, and minimum diameters and cross-sectional area of the main and branch pulmonary arteries for systole and diastole.   Conclusion: We report systolic and diastolic mean, maximum, and minimum diameters and cross-sectional areas along with Z-scores and normative curves for the main and branch pulmonary arteries in children derived using ECG-gated cardiac CTA. We believe our results can help identify abnormally sized main and branch pulmonary arteries. What is Known: • Normative data for intracardiac and extracardiac vascular structures in the pediatric population are available for echocardiography, cardiac MRI and non-ECG gated CTA. • Z-scores with standard deviations are commonly used in children, but SDs are not constant across body sizes due to heteroscedasticity. What is New: • Allometric exponent was derived for each parameter and the parameter/body surface area (BSA) was established. • This is the first ECG-gated CTA study to provide normative en face systolic, diastolic diameters and cross-sectional areas along with Z-scores and normative curves for the main and branch pulmonary arteries in children.

Influence of improved antenatal detection on the outcomes of complete atrioventricular block diagnosed in fetal-neonatal life and childhood periods - a single-centre experience in South Wales for 55 years

OBJECTIVE

This study aimed to analyse the influence of improved antenatal detection on the course, contemporary outcomes, and mortality risk factors of the complete atrioventricular block during fetal-neonatal and childhood periods in South Wales.

METHODS

The clinical characteristics and outcomes of complete atrioventricular block in patients without structural heart disease at the University Hospital of Wales from January 1966 to April 2021 were studied. Patients were divided into two groups according to their age at diagnosis: I-fetal-neonatal and II-childhood. Contemporary outcomes during the post-2001 era were compared with historical data preceding fetal service development and hence earlier detection.

RESULTS

There were 64 patients: 26 were identified in the fetal-neonatal period and the remaining 38 in the childhood period. Maternal antibodies/systemic lupus erythematosus disease (anti-Ro/Sjögren's-syndrome-related Antigen A and/or anti-La/Sjögren's-syndrome-related Antigen B) were present in 15 (57.7%) of the fetal-neonatal. Fetal/neonatal and early diagnosis increased after 2001 with an incidence of 1:25000 pregnancies. Pacemaker implantation was required in 34 patients, of whom 13 were diagnosed in the fetal-neonatal group. Survival rates in cases identified before 2001 were at 96.3% (26/27), whereas it was 83.8% (31/37) in patients diagnosed after 2001 (P > 0.05). Other mortality risk factors comprised a lower gestational week at birth, maternal antibodies, and an average ventricular heart rate of < 55 bpm.

CONCLUSIONS

Fetal diagnosis of complete atrioventricular block is still portends high fetal and neonatal mortality and morbidity despite significantly improved antenatal detection after 2001. Pacemaker intervention is needed earlier in the fetal-neonatal group. Whether routine antenatal medical treatment might alter this outcome calls for further prospective multicentre studies.

Guidelines for Performing a Comprehensive Pediatric Transthoracic Echocardiogram: Recommendations From the American Society of Echocardiography

Echocardiography is a fundamental component of pediatric cardiology, and appropriate indications have been established for its use in the setting of suspected, congenital, or acquired heart disease in children. Since the publication of guidelines for pediatric transthoracic echocardiography in 2006 and 2010, advances in knowledge and technology have expanded the scope of practice beyond the use of traditional modalities such as two-dimensional, M-mode, and Doppler echocardiography to evaluate the cardiac segmental structures and their function. Adjunct modalities such as contrast, three-dimensional, and speckle-tracking echocardiography are now used routinely at many pediatric centers. Guidelines and recommendations for the use of traditional and newer adjunct modalities in children are described in detail in this document. In addition, suggested protocols related to standard operations, infection control, sedation, and quality assurance and improvement are included to provide an organizational structure for centers performing pediatric transthoracic echocardiograms.

Natural history of cardiac findings in mucopolysaccharidosis type I: report from an international registry

Mucopolysaccharidosis type I is an inborn error of glycosaminoglycan catabolism with phenotypes ranging from severe (Hurler syndrome) to attenuated (Hurler-Scheie and Scheie syndromes). Cardiovascular involvement is common and contributes significantly to morbidity and mortality. We conducted a retrospective analysis of the prevalence and natural history of cardiac abnormalities in treatment-naïve individuals enrolled in the international Mucopolysaccharidosis Type I Registry. Interrogation of echocardiography data (presence of cardiac valve regurgitation and/or stenosis; measurements of left ventricular chamber dimensions in diastole and systole, diastolic left ventricular posterior wall and interventricular septal thicknesses and ventricular systolic function (shortening fraction)) showed that mitral regurgitation was the most common and earliest finding for individuals with both severe (58.3%, median age 1.2 years) and attenuated (74.2%, median age 8.0 years) disease. Left-sided valve stenosis was also common in individuals with attenuated disease (mitral 30.3%; aortic 25%). Abnormal ventricular wall and septal thickness (Z-scores ≥2) were observed early in both phenotypes. Z-scores for diastolic left ventricular posterior wall and interventricular septal thicknesses increased with age in the severe phenotype (annualised slopes of 0.2777 [p = 0.037] and 0.3831 [p = 0.001], respectively); a similar correlation was not observed in the attenuated phenotype (annualised slopes of -0.0401 [p = 0.069] and -0.0029 [p = 0.875], respectively). Decreased cardiac ventricular systolic function (defined as shortening fraction <28%) was uncommon but, when noted, was more frequent in infants with the severe phenotype. While cardiac abnormalities occur early in both severe and attenuated mucopolysaccharidosis type I, the pattern of valve dysfunction and progression of ventricular abnormalities vary by phenotype.

Neonates and Infants with Left Heart Obstruction and Borderline Left Ventricle Undergoing Biventricular Repair: What Do We Know about Long-Term Outcomes? A Critical Review

BACKGROUND

The decision to perform biventricular repair (BVR) in neonates and infants presenting with either single or multiple left ventricle outflow obstructions (LVOTOs) and a borderline left ventricle (BLV) is subject to extensive discussion, and limited information is known regarding the long-term outcomes. As a result, the objective of this study is to critically assess and summarize the available data regarding the prognosis of neonates and infants with LVOTO and BLV who underwent BVR.

METHODS

In February 2023, we conducted a review study with three different medical search engines (the National Library of Medicine, Science Direct, and Cochrane Library) for Medical Subject Headings and free text terms including "congenital heart disease", "outcome", and "borderline left ventricle". The search was refined by adding keywords for "Shone's complex", "complex LVOT obstruction", "hypoplastic left heart syndrome/complex", and "critical aortic stenosis".

RESULTS

Out of a total of 51 studies, 15 studies were included in the final analysis. The authors utilized heterogeneous definitions to characterize BLV, resulting in considerable variation in inclusion criteria among studies. Three distinct categories of studies were identified, encompassing those specifically designed to evaluate BLV, those focused on Shone's complex, and finally those on aortic stenosis. Despite the challenges associated with comparing data originating from slightly different cardiac defects and from different eras, our results indicate a favorable survival rate and clinical outcome following BVR. However, the incidence of reintervention remains high, and concerns persist regarding residual pulmonary hypertension, which has been inadequately investigated.

CONCLUSIONS

The available data concerning neonates and infants with LVOTO and BLV who undergo BVR are inadequate and fragmented. Consequently, large-scale studies are necessary to fully ascertain the long-term outcome of these complex defects.

A Patient Similarity Network (CHDmap) to Predict Outcomes After Congenital Heart Surgery: Development and Validation Study

Background

Although evidence-based medicine proposes personalized care that considers the best evidence, it still fails to address personal treatment in many real clinical scenarios where the complexity of the situation makes none of the available evidence applicable. "Medicine-based evidence" (MBE), in which big data and machine learning techniques are embraced to derive treatment responses from appropriately matched patients in real-world clinical practice, was proposed. However, many challenges remain in translating this conceptual framework into practice.

Objective

This study aimed to technically translate the MBE conceptual framework into practice and evaluate its performance in providing general decision support services for outcomes after congenital heart disease (CHD) surgery.

Methods

Data from 4774 CHD surgeries were collected. A total of 66 indicators and all diagnoses were extracted from each echocardiographic report using natural language processing technology. Combined with some basic clinical and surgical information, the distances between each patient were measured by a series of calculation formulas. Inspired by structure-mapping theory, the fusion of distances between different dimensions can be modulated by clinical experts. In addition to supporting direct analogical reasoning, a machine learning model can be constructed based on similar patients to provide personalized prediction. A user-operable patient similarity network (PSN) of CHD called CHDmap was proposed and developed to provide general decision support services based on the MBE approach.

Results

Using 256 CHD cases, CHDmap was evaluated on 2 different types of postoperative prognostic prediction tasks: a binary classification task to predict postoperative complications and a multiple classification task to predict mechanical ventilation duration. A simple poll of the k-most similar patients provided by the PSN can achieve better prediction results than the average performance of 3 clinicians. Constructing logistic regression models for prediction using similar patients obtained from the PSN can further improve the performance of the 2 tasks (best area under the receiver operating characteristic curve=0.810 and 0.926, respectively). With the support of CHDmap, clinicians substantially improved their predictive capabilities.

Conclusions

Without individual optimization, CHDmap demonstrates competitive performance compared to clinical experts. In addition, CHDmap has the advantage of enabling clinicians to use their superior cognitive abilities in conjunction with it to make decisions that are sometimes even superior to those made using artificial intelligence models. The MBE approach can be embraced in clinical practice, and its full potential can be realized.

Percutaneous pulmonary valve implantation in children and adults with an age and gender-specific analysis

BACKGROUND

There are limited studies with medium-term follow-up following percutaneous pulmonary valve implantation and no studies with a gender-specific analysis.

AIMS

To report clinical outcomes up to five years following percutaneous pulmonary valve implantation using the two most common balloon expandable valves in a mixed population of paediatric and adult patients with an age and gender-specific analysis.

METHODS

This was a single-centre retrospective observation study. Relevant data were obtained retrospectively from the case files. Age and gender- specific analysis was performed using SPSS.

RESULTS

Totally, 58 patients (13 children, 45 adults) underwent percutaneous pulmonary valve implantation. Statistically significant reduction in median right ventricular outflow tract flow velocity following valve implantation was maintained for the whole five years in adults but not in children. There were no gender-specific differences despite the study being adequately powered. Independent of valve type used, there was significant reduction of the right ventricular outflow tract flow velocity in the immediate post valve implantation period (Edwards P = 0.001, Melody P = 0.013). There was a significant negative correlation between implanted valve Z-score and subsequent right ventricular outflow tract gradient during the first two years following valve implantation.

CONCLUSION

Gender does not significantly affect valve function following percutaneous pulmonary valve implantation. It is important to consider patients' age and body surface area in relation to existing right ventricular outflow tract size during decisions for percutaneous pulmonary valve implantation.

Normalization of Cardiac Structural dimension and Function to Body Surface Area in South East Nigeria Children

BACKGROUND

Standardizing cardiac valve structures and function to body surface area will help the clinician and surgeons in decision-making.

AIM

To evaluate the z-scores of the sizes of cardiac structures and function and to present them in Gaussian curves and reference values.

MATERIALS AND METHODS

This was a cross-sectional study that involved 300 apparently healthy children. This study was performed among healthy children from birth to 18 years. Children with a normal echocardiogram, those with no chronic illness, no congenital heart defect, and no acquired heart defect were included in the study.

RESULT

The majority fell within the normal limits, as shown in the Gaussian curves. For instance, 40 (13.3%) of atrioventricular (AV) valve diameters were +1 Z-score above the normal, and only 5 (1.7%) were +2 Z-score above the normal. About 9.3% (28/300) had below -2 Z-score below normal, while only 5% had -1 Z-score below normal. Similarly, the left ventricular function z-scores were also derived at -3 Z-scores to +3 Z-scores. The standard reference values were compared with the results obtained from our Z score values. There was no significant difference noted in the Z-scores. P values ranged from 0.07 to 0.84 for all the cardiac structures except for gender, where Z-scores of the mitral valve and left pulmonary artery varied significantly (P = 0.02).

CONCLUSION

Reference values of cardiac structure and function were presented using Z scores, and we noted no significant difference when compared with the Western standard values except for the mitral valve and left pulmonary artery.

Sudden cardiac death in childhood RASopathy-associated hypertrophic cardiomyopathy: Validation of the HCM risk-kids model and predictors of events

BACKGROUND

RASopathies account for nearly 20% of cases of childhood hypertrophic cardiomyopathy (HCM). Sudden cardiac death (SCD) occurs in patients with RASopathy-associated HCM, but the risk factors for SCD have not been systematically evaluated.

AIM

To validate the HCM Risk-Kids SCD risk prediction model in children with RASopathy-associated HCM and investigate potential specific SCD predictors in this population.

METHODS

Validation of HCM Risk-Kids was performed in a retrospective cohort of 169 patients with a RASopathy-associated HCM from 15 international paediatric cardiology centres. Multiple imputation by chained equations was used for missing values related to the HCM Risk-Kids parameters.

RESULTS

Eleven patients (6.5%) experienced a SCD or equivalent event at a median age of 12.5 months (IQR 7.7-28.64). The calculated SCD/equivalent event incidence was 0.78 (95% CI 0.43-1.41) per 100 patient years. Six patients (54.54%) with an event were in the low-risk category according to the HCM Risk-Kids model. Harrell's C index was 0.60, with a sensitivity of 9.09%, specificity of 63.92%, positive predictive value of 1.72%, and negative predictive value of 91%; with a poor distinction between the different risk groups. Unexplained syncope (HR 42.17, 95% CI 10.49-169.56, p < 0.001) and non-sustained ventricular tachycardia (HR 5.48, 95% CI 1.58-19.03, p < 0.007) were predictors of SCD on univariate analysis.

CONCLUSION

Unexplained syncope and the presence of NSVT emerge as predictors for SCD in children with RASopathy-associated HCM. The HCM Risk-Kids model may not be appropriate to use in this population, but larger multicentre collaborative studies are required to investigate this further.

Comparison between the modified Blalock-Taussig shunt and right ventricular outflow tract stent in the palliative treatment for tetralogy of Fallot

OBJECTIVES

For patients with tetralogy of Fallot (TOF) who are not suitable candidates for primary corrective surgery or have a high surgical risk, transcatheter right ventricular outflow tract (RVOT) stent implantation is considered a safe and effective palliative intervention. This study aims to investigate the therapeutic outcomes of RVOT stent implantation in neonates and infants with TOF in comparison with the modified Blalock-Taussig shunt (mBTS) and to compare the impact of the 2 palliative interventions on arterial oxygen saturation and pulmonary artery development in pediatric patients.

METHODS

Clinical data of 32 patients with TOF admitted to the Second Xiangya Hospital of Central South University from March 2011 to March 2021 were retrospectively collected. The patients were divided into an mBTS group (undergoing mBTS, n=15) and a stent implantation group (undergoing RVOT stenting, n=17) according to the surgical procedures. The 2 groups were assessed and compared in the surgical-related arterial oxygen saturation, postoperative complication rate, mortality rate, and re-intervention rate. The development of the patients' main pulmonary artery, right pulmonary artery, and left pulmonary artery was assessed by z-scores according to echocardiographic results.

RESULTS

The children in the stent implantation group were younger and less weighed compared with the mBTS group (both P<0.05). Compared with the preoperative period, children in the stent implantation group had significantly higher arterial oxygen saturation [(75±17)% vs (96±3)%, P=0.026]; z-scores of pulmonary trunk [(-2.82±1.27) points vs (0.86±0.77) points, P=0.014], right pulmonary artery [(-1.88±0.59) points vs (-0.28±0.71) points, P=0.011], and left pulmonary artery [(-2.34±0.36) points vs (-1.67±0.36) points, P=0.036] were significantly increased. However, there were no significant differences in arterial oxygen saturation and pulmonary artery z-scores between pre- and post-mBTS procedures (all P>0.05).

CONCLUSIONS

RVOT stent would have good surgical outcomes used in TOF patients with low weight and severe comorbidities. It also leads to an higher postoperative oxygen saturation and better promotion of pulmonary artery growth with RVOT stent compared to mBTS.

Aortic growth after arch reconstruction with patch augmentation: a 2-decade experience

OBJECTIVES

Optimal aortic sizing during aortic arch reconstruction remains unknown. Negative effects of arch under- or oversizing are well-published. We aimed to characterize longitudinal aortic growth after patch-augmented arch reconstruction to identify the initial reconstructed arch size that results in normal mid-term arch dimensions.

METHODS

Single-centre, retrospective review of infants undergoing Damus-Kaye-Stansel (DKS) or non-DKS patch-augmented aortic arch reconstruction between 2000 and 2021. Ascending aorta, proximal and distal transverse arch, aortic isthmus (AIsth) and descending aorta dimensions were measured in postoperative echocardiograms (<3 months from index operation) and cross-sectional imaging (>12 months). Longitudinal changes to aortic dimensions and z-scores were analysed. Secondary outcomes included reintervention, valve and ventricular function, mortality and transplantation.

RESULTS

Fifty-four patients (16 DKS, 38 non-DKS) were included. At 6.3 [2.2, 12.0]-year follow-up, all aortic segments grew significantly in both groups, while z-scores remained unchanged except for non-DKS proximal and distal transverse arch z-scores, which significantly increased (P < 0.05 each). When stratified by initial postoperative z-score (z < -1, -1 ≤ z ≤ 1, z > 1), non-DKS patients with initial AIsth z-score <-1 had a final z-score significantly smaller than both the targeted z-score zero (P = 0.014) and final z-score in a group with initial postoperative z-score ±1 (P = 0.009). Valve and ventricular function remained stable. Eighteen patients required reintervention, 1 died and 1 underwent transplant.

CONCLUSIONS

Over mid-term follow-up, aortic growth after arch reconstruction with patch augmentation was proportional when repaired to normal z-score dimensions, aside from proximal transverse arch, which disproportionately dilated. AIsth undersizing prevailed mid-term and trended towards a higher reintervention rate. Initial reconstruction between z-score 0 and +1 resulted in maintenance of that z-score size at mid-term follow-up. Overall, it is crucial to achieve targeted aortic sizing at index operation to maintain appropriate aortic dimensions over time and reduce reintervention risk with specific focus on the AIsth.

Consistency of the continuous flow pressure gradient despite aortic arch anomalies co-existing with coarctation

Aims

Severity assessment for coarctation of the aorta (CoA) is challenging due to concomitant morphological anomalies (complex CoA) and inaccurate Doppler-based indices. Promising diagnostic performance has been reported for the continuous flow pressure gradient (CFPG), but it has not been studied in complex CoA. Our objective was to characterize the effect of complex CoA and associated hemodynamics on CFPG in a clinical cohort.

Methods and Results

Retrospective analysis identified discrete juxtaductal (n=25) and complex CoA (n=43; transverse arch and/or isthmus hypoplasia) patients with arm-leg systolic blood pressure gradients (BPG) within 24 hours of echocardiography for comparison to BPG by conventional Doppler indices (simplified Bernoulli equation and modified forms correcting for proximal kinetic energy and/or recovered pressure). Results were interpreted using the current CoA guideline (BPG ≥20 mmHg) to compare diagnostic performance indicators including receiver operating characteristic curves, sensitivity, specificity, and diagnostic accuracy, among others. Echocardiography Z-scored aortic diameters were applied with computational stimulations from a preclinical CoA model to understand aspects of the CFPG driving performance differences.Diagnostic performance was substantially reduced from discrete to complex CoA for conventional Doppler indices calculated from patient data, and by hypoplasia and/or long segment stenosis in simulations. In contrast, diagnostic indicators for the CFPG only modestly dropped for complex vs discrete CoA. Simulations revealed differences in performance due to inclusion of the Doppler velocity index and diastolic pressure half-time in the CFPG calculation.

Conclusion

CFPG is less affected by aortic arch anomalies co-existing with CoA when compared to conventional Doppler indices.

Symptomatic presentation influences outcomes in pediatric restrictive cardiomyopathy

Introduction

Children with restrictive cardiomyopathy (RCM) traditionally have a poor prognosis, with most patients either dying or requiring heart transplantation within 2 years of diagnosis. The development of symptoms in RCM suggests advanced disease. However, as screening practices evolve and lead to diagnosis of early disease, identifying appropriate timing of transplant listing becomes increasingly important. In this context we compared outcomes of children with RCM presenting with clinical symptoms to those asymptomatic at initial presentation.

Methods

This retrospective cohort study included 25 patients with RCM presenting to a quaternary care center between 2001 and 2018. Times to transplantation, death, and a composite outcome of adverse cardiac events (CPR, cardioversion, inotropic support, mechanical ventilation, mechanical support, or heart transplant) were compared between those symptomatic and asymptomatic at presentation.

Results

At 2 years following diagnosis, patients asymptomatic at presentation had a significantly better transplant-free survival at 57% compared to 17% for symptomatic patients (p = 0.03). Those asymptomatic at diagnosis also had significantly improved cardiac event-free survival at 71% compared to symptomatic patients at 25% (p = 0.01). In multivariable analysis, cardiac symptoms at presentation remained an independent risk factor for heart-transplant or death [hazard ratio 5.17 (1.28-20.85), p = 0.02].

Conclusion

Patients with RCM who are symptomatic at time of diagnosis have significantly worse transplant-free survival and cardiac event-free survival. Given current practice variability in timing of transplant listing, the presence of any cardiac symptoms is an important negative prognostic marker and should prompt urgent transplant listing.

Outcomes After Hybrid Palliation for Infants With Critical Left Heart Obstruction

BACKGROUND

Hybrid palliation (bilateral pulmonary artery banding with or without ductal stenting) is an initial management strategy for infants with critical left heart obstruction and serves as palliation until subsequent operations are pursued.

OBJECTIVES

This study sought to determine patient characteristics and factors associated with subsequent outcomes for infants who underwent hybrid palliation.

METHODS

From 2005 to 2019, 214 of 1,236 prospectively enrolled infants within the Congenital Heart Surgeons' Society's critical left heart obstruction cohort underwent hybrid palliation across 24 institutions. Multivariable hazard modeling with competing risk methodology was performed to determine risk and factors associated with outcomes of biventricular repair, Fontan procedure, transplantation, or death.

RESULTS

Preoperative comorbidities (eg, prematurity, low birth weight, genetic syndrome) were identified in 70% of infants (150 of 214). Median follow-up was 7 years, ranging up to 17 years. Overall 12-year survival was 55%. At 5 years after hybrid palliation, 9% had biventricular repair, 36% had Fontan procedure, 12% had transplantation, 35% died without surgical endpoints, and 8% were alive without an endpoint. Factors associated with transplantation were absence of ductal stent, older age, absent interatrial communication, smaller aortic root size, larger tricuspid valve area z-score, and larger left ventricular volume. Factors associated with death were low birth weight, concomitant genetic syndrome, cardiopulmonary bypass use during hybrid palliation, moderate to severe tricuspid valve regurgitation, and smaller ascending aortic size.

CONCLUSIONS

Mortality remains high after hybrid palliation for infants with critical left heart obstruction. Nonetheless, hybrid palliation may facilitate biventricular repair for some infants and for others may serve as stabilization for intended functional univentricular palliation or primary transplantation.

Short-term outcomes of South African children with multisystem inflammatory syndrome in children: a prospective cohort study

BACKGROUND

Despite the life-threatening presentation of multisystem inflammatory syndrome in children (MIS-C), the overall prognosis is favourable in centres with access to appropriate supportive care. In this study, we investigate the short-term outcomes in children with MIS-C in Cape Town, South Africa.

METHODS

This prospective observational cohort study included children <13 years who fulfilled the WHO case definition of MIS-C and were admitted to Tygerberg Hospital in Cape Town, South Africa between 1 June 2020 and 31 October 2021. Clinical features were recorded at baseline and at follow-up at the 6-week cardiology and 3-month rheumatology-immunology clinics, respectively.

FINDINGS

Fifty-three children with a median age of 7.4 years (IQR 4.2-9.9) were included. There was a slight male predominance (30/53; 56.6%) and the majority was of mixed ancestry (28/53; 52.83%) or black African ancestry (24/53; 45.3%). Fourteen children (14/53; 26.4%) had comorbid disease. The median length of hospital stay was 8 days (IQR 6-10). All children had an echocardiogram performed at baseline of which 39 were abnormal (39/53; 73.6%). All children were discharged alive. The median days from discharge to cardiology follow-up was 39 days (IQR 33.5-41.5) and for rheumatology-immunology clinic was 70.5 days (IQR 59.5-85.0). Eleven children (11/41; 26.8%) had a persistently abnormal echocardiogram at cardiology follow-up. Systemic inflammation and organ dysfunction resolved in most.

INTERPRETATION

Although the short-term outcomes of MIS-C in our cohort were generally good, the cardiac morbidity needs further characterisation and follow-up.

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.

A 3D printed electronic wearable device to generate vertical, horizontal and phono-articulatory jaw movement parameters: A concept implementation

PURPOSE

The current research aimed to develop a concept open-source 3D printable, electronic wearable head gear to record jaw movement parameters.

MATERIALS & METHODS

A 3D printed wearable device was designed and manufactured then fitted with open-source sensors to record vertical, horizontal and phono-articulatory jaw motions. Mean deviation and relative error were measured invitro. The device was implemented on two volunteers for the parameters of maximum anterior protrusion (MAP), maximum lateral excursion (MLE), normal (NMO), and maximum (MMO) mouth opening and fricative phono-articulation. Raw data was normalized using z-score and root mean squared error (RMSE) values were used to evaluate relative differences in readings across the two participants.

RESULTS

RMSE differences across the left and right piezoresistive sensors demonstrated near similar bilateral movements during normal (0.12) and maximal mouth (0.09) opening for participant 1, while varying greatly for participant 2 (0.25 and 0.14, respectively). There were larger differences in RMSE during accelerometric motion in different axes for MAP, MLE and Fricatives.

CONCLUSION

The current implementation demonstrated that a 3D printed electronic wearable device with open-source sensor technology can record horizontal, vertical, and phono-articulatory maxillomandibular movements in two participants. However, future efforts must be made to overcome the limitations documented within the current experiment.

Comparison of two echocardiography-based methods for evaluating pediatric left ventricular diastolic dysfunction

Objectives

To investigate the consistency between the 2016 America Society of Echocardiography (ASE)/European Association of Cardiovascular Imaging (EACVI) guideline-based recommendations and the body surface area (BSA)-transformed Z value-based cut-off for the assessment of left ventricular diastolic function (LVDF) in children.

Methods

Clinical data of children with heart failure (HF) and those with a high risk of HF and a low risk of HF were collected from the Children's Hospital of Chongqing Medical University between March 2021 and October 2022. The mitral annular e' velocity, lateral E/e' ratio, left atrial volume index, and peak tricuspid regurgitation velocity were detected by Echocardiography. The cut-off values recommended by the 2016 ASE/EACVI guidelines and the cut-off value based on the BSA-transformed Z value were used to evaluate LVDF. The consistencies and differences of the two criteria were compared.

Results

A total of 132 children with HF, 189 with a high risk of HF, and 231 with a low risk of HF, were enrolled. The consistency of the two criteria in evaluating LVDF in children with HF and with high risk of HF was moderate, with weighted kappa coefficients of 0.566 and 0.468, respectively (P < 0.001). The positivity rate of left ventricular diastolic dysfunction (LVDD) with Z value-based criteria (HF group, 23.5%; high-risk group, 8.5%) was higher than that with guideline-based criteria (HF group, 15.6%; high-risk group, 3.2%). In children with a low risk of HF, no case with LVDD was found. The consistency between the two criteria for grading the degree of LVDD was moderate, with a kappa coefficient of 0.522 (P = 0.001). The degree of LVDD according to the Z value-based criteria was higher than that of the guideline-based criteria (P = 0.004).

Conclusions

The Z value-based criteria used to evaluate LVDD in children with HF and high risk of HF may be more conducive to the early identification of LVDD, thereby permitting the possibility of early treatment intervention.

Norwood operation versus comprehensive stage II after bilateral pulmonary artery banding palliation for infants with critical left heart obstruction

OBJECTIVE

To determine patient characteristics and outcomes after Norwood versus comprehensive stage II (COMPSII) for infants with critical left heart obstruction who had prior hybrid palliation (bilateral pulmonary artery banding ± ductal stent).

METHODS

From 23 Congenital Heart Surgeons' Society institutions (2005-2020), 138 infants underwent hybrid palliation followed by either Norwood (n = 73, 53%) or COMPSII (n = 65). Baseline characteristics were compared between Norwood and COMPSII groups. Parametric hazard model with competing risk methodology was used to determine risk and factors associated with outcomes of Fontan, transplantation, or death.

RESULTS

Infants who underwent Norwood versus COMPSII had a higher prevalence of prematurity (26% vs 14%, P = .08), lower birth weight (median 2.8 vs 3.2 kg, P < .01) and less frequent ductal stenting (37% vs 99%; P < .01). Norwood was performed at a median age of 44 days and median weight of 3.5 kg, versus COMPSII at 162 days and 6.0 kg (both P < .01). Median follow-up was 6.5 years. At 5 years after Norwood and COMPSII, respectively; 50% versus 68% had Fontan (P = .16), 3% versus 5% had transplantation (P = .70), 40% versus 15% died (P = .10), and 7% versus 11% are alive without transition, respectively. For factors associated with either mortality or Fontan, only preoperative mechanical ventilation occurred more frequently in the Norwood group.

CONCLUSIONS

Higher prevalence of prematurity, lower birth weight, and other patient-related characteristics in the Norwood versus COMPSII groups may influence differences in outcomes that were not statistically significant for this limited risk-adjusted cohort. The clinical decision regarding Norwood versus COMPSII after initial hybrid palliation remains challenging.

Natural History of Nonsurgical Complete Atrioventricular Block in Children and Predictors of Pacemaker Implantation

BACKGROUND

Data on the natural history of complete atrioventricular block (CAVB) in children are scarce, and criteria for pacemaker (PM) implantation are based on low levels of evidence.

OBJECTIVES

This study aimed to evaluate the natural course and predictors of PM implantation in a nationwide cohort of pediatric patients with nonsurgical CAVB.

METHODS

All children with CAVB in the absence of structural heart disease presenting from 1977 to 2016 were retrospectively identified, yielding 95 subjects with a mean age of 4.05 years at the first presentation with a follow-up median of 0.80 years (IQR: 0.02-6.82 years). PM implantation was performed according to the available guidelines. Serial 24-hour Holter recordings and echocardiograms were reviewed. Predictors of PM implantation performed >1 month after the first presentation were evaluated.

RESULTS

The minimum and mean 24-hour heart rates and maximum RR intervals had a nonlinear correlation with age (P < 0.0001 for all). The left ventricular (LV) size was moderately increased, and the shortening fraction was normal in the majority throughout follow-up. PM implantation was performed in 62 patients (65.3%) reaching guideline criteria. The mean 24-hour heart rate at presentation was a predictor of subsequent PM implantation (HR: 0.938; 95% CI: 0.894-0.983; P = 0.003 per unit increase) regardless of age at presentation. Patients presenting with a mean 24-hour heart rate >58 beats/min (>75th percentile) had a high probability of freedom from PM within the subsequent 5 years (91.7% vs 44.4%; P < 0.001).

CONCLUSIONS

Pediatric patients with CAVB showed an age-dependent decrease in heart rate, moderate LV dilation, and preserved LV function. The probability of subsequent PM implantation could be predicted by the heart rate profile at presentation, defining a low-risk group and allowing for individualized follow-up.

Analysis of risk stratification and prevention of sudden death in pediatric patients with hypertrophic cardiomyopathy: Dilemmas and clarity

Hypertrophic cardiomyopathy (HCM) has been considered the most common cause of sudden death (SD) in the young. However, introduction of implantable cardioverter-defibrillators (ICDs) in HCM has proved highly effective and the mainstay of preventing SD in children, adolescents, and adults by terminating malignant ventricular tachyarrhythmias. Nevertheless, ICD decision making is generally regarded as more difficult in pediatrics, and the strategy for selecting ICD patients from this population remains without consensus. Prospective studies in HCM children and adolescents have shown the American Heart Association/American College of Cardiology traditional major risk marker strategy to be reliable with >90% sensitivity in selecting patients for SD prevention. International data in >2000 young HCM patients assembled over 20 years who were stratified by major risk markers showed ICDs effectively prevented SD in 20%. Alternatively, novel quantitative risk scoring initiatives provide 5-year risk estimates that are potentially useful as adjunctive tools to facilitate discussion of prophylactic ICD risks vs benefit but are as yet unsupported by prospective outcome studies. Risk scoring strategies are characterized by reasonable discriminatory statistical power (C-statistic 0.69-0.76) for identifying patients with SD events but with relatively low sensitivity, albeit with specificity comparable with the risk marker strategy. While some reticence for obligating healthy-appearing young patients to lifelong device implants is understandable, underutilization of the ICD in high-risk children and adolescents can represent a lost opportunity for fulfilling the long-standing aspiration of SD prevention. This review provides a critical assessment of the current strengths and weaknesses of SD risk stratification strategies in young HCM patients in an effort to clarify clinical decision making in this challenging subpopulation.

Mechanisms of Aortic Dilation in Patients With Bicuspid Aortic Valve: JACC State-of-the-Art Review

Bicuspid aortic valve is the most common congenital heart disease and exposes patients to an increased risk of aortic dilation and dissection. Aortic dilation is a slow, silent process, leading to a greater risk of aortic dissection. The prevention of adverse events together with optimization of the frequency of the required lifelong imaging surveillance are important for both clinicians and patients and motivated extensive research to shed light on the physiopathologic processes involved in bicuspid aortic valve aortopathy. Two main research hypotheses have been consolidated in the last decade: one supports a genetic basis for the increased prevalence of dilation, in particular for the aortic root, and the second supports the damaging impact on the aortic wall of altered flow dynamics associated with these structurally abnormal valves, particularly significant in the ascending aorta. Current opinion tends to rule out mutually excluding causative mechanisms, recognizing both as important and potentially clinically relevant.

Natural History of Hypertrophic Cardiomyopathy in Noonan Syndrome With Multiple Lentigines

BACKGROUND

We aimed to examine clinical features and outcomes of consecutive molecularly characterized patients with Noonan syndrome with multiple lentigines and hypertrophic cardiomyopathy.

METHODS

A retrospective, longitudinal multicenter cohort of consecutive children and adults with a genetic diagnosis of Noonan syndrome with multiple lentigines and hypertrophic cardiomyopathy between 2002 and 2019 was assembled. We defined a priori 3 different patterns of left ventricular remodeling during follow-up: (1) an increase in ≥15% of the maximal left ventricular wall thickness (MLVWT), both in mm and z-score (progression); (2) a reduction ≥15% of the MLVWT, both in mm and z-score (absolute regression); (3) a reduction ≥15% of the MLVWT z-score with a stable MLVWT in mm (relative regression). The primary study end point was a composite of cardiovascular death, heart transplantation, and appropriate implantable cardioverter defibrillator-shock.

RESULTS

The cohort comprised 42 patients with Noonan syndrome with multiple lentigines and hypertrophic cardiomyopathy, with a median age at diagnosis of 3.5 (interquartile range, 0.2-12.3) years. Freedom from primary end point was 92.7% (95% CI, 84.7%-100%) 1 year after presentation and 80.9% (95% CI, 70.1%-90.7%) at 5 years. Patients with MLVWT z-score >13.7 showed reduced survival compared with those with <13.7. During a median follow-up of 3.7 years (interquartile range, 2.6-7.9), absolute regression was the most common type of left ventricular remodeling (n=9, 31%), followed by progression (n=6, 21%), and relative regression (n=6, 21%).

CONCLUSIONS

These findings provide insights into the natural history of left ventricular hypertrophy, and can help inform clinicians regarding risk stratification and clinical outcomes in patients with Noonan syndrome with multiple lentigines and hypertrophic cardiomyopathy.