Impact of obesity on ventricular size and function in children, adolescents and adults with Tetralogy of Fallot after initial repair

Development and Validation of a Mortality Risk Score for Repaired Tetralogy of Fallot

BACKGROUND

Robust risk assessment is crucial for the growing repaired tetralogy of Fallot population at risk of major adverse clinical outcomes; however, current tools are hindered by lack of validation. This study aims to develop and validate a risk prediction model for death in the repaired tetralogy of Fallot population.

METHODS AND RESULTS

Patients with repaired tetralogy of Fallot enrolled in the INDICATOR (International Multicenter Tetralogy of Fallot Registry) cohort with clinical, arrhythmia, cardiac magnetic resonance, and outcome data were included. Patients from London, Amsterdam, and Boston sites were placed in the development cohort; patients from the Toronto site were used for external validation. Multivariable Cox regression was used to evaluate factors associated with time from cardiac magnetic resonance until the primary outcome: all-cause death. Of 1552 eligible patients (n=1221 in development, n=331 in validation; median age at cardiac magnetic resonance 23.4 [interquartile range, 15.6-35.6] years; median follow up 9.5 years), 102 (6.6%) experienced the primary outcome. The multivariable Cox model performed similarly during development (concordance index, 0.83 [95% CI, 0.78-0.88]) and external validation (concordance index, 0.80 [95% CI, 0.71-0.90]) and identified older age at cardiac magnetic resonance, obesity, type of tetralogy of Fallot repair, higher right ventricular end-systolic volume index, and lower biventricular global function index as independent predictors of death. A risk-scoring algorithm dividing patients into low-risk (score ≤4) versus high-risk (score >4) groups was validated to effectively discriminate risk of death (15-year survival of 95% versus 74%, respectively; P<0.001).

CONCLUSIONS

This externally validated mortality risk prediction algorithm can help identify vulnerable patients with repaired tetralogy of Fallot who may benefit from targeted interventions.

Cardiovascular magnetic resonance reference values of right ventricular volumetric variables in patients with hypoplastic left heart syndrome

BACKGROUND

Cardiovascular magnetic resonance (CMR) has established itself as the gold standard for serial assessment of systemic right ventricular (RV) performance but due to the lack of standardized RV reference values for hypoplastic left heart syndrome (HLHS) patients, the interpretation of RV volumetric data in HLHS remains difficult. Therefore, this study aimed to close this gap by providing CMR reference values for the systemic RV in HLHS patients.

METHODS

CMR scans of 160 children, adolescents, and young adults (age range 2.2-25.2 years, 106 males) with HLHS were retrospectively evaluated. All patients were studied following total cavopulmonary connection. Short-axis stacks were used to measure RV end-diastolic and end-systolic volumes (RVEDV, RVESV), RV stroke volume (RVSV), RV ejection fraction (RVEF), and RV end-diastolic myocardial mass (RVEDMM). Univariable and multiple linear regression analyses were performed to assess associations between RV parameters and demographic and anthropometric characteristics. Following the results of the regression analysis, reference graphs and tables were created with the Lambda-Mu-Sigma method.

RESULTS

Multiple linear regression analysis showed strong associations between body height and RVEDV, RVESV as well as RVSV. Age was highly associated with RVEDMM. Therefore, percentile curves and tables were created with respect to body height (RVEDV, RVESV, RVSV) and age (RVEDMM). The influence of demographic and anthropometric parameters on RVEF was mild, thus no percentile curves and tables for RVEF are provided.

CONCLUSION

We were able to define CMR reference values for RV volumetric variables for HLHS patients. These data might be useful for the assessment and interpretation of CMR scans in these patients and for research in this field.

Technical recommendations for computed tomography guidance of intervention in the right ventricular outflow tract: Native RVOT, conduits and bioprosthetic valves:: A white paper of the Society of Cardiovascular Computed Tomography (SCCT), Congenital Heart Surgeons' Society (CHSS), and Society for Cardiovascular Angiography & Interventions (SCAI)

This consensus document for the performance of Cardiovascular Computed Tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multi-modality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Technical Recommendations for Computed Tomography Guidance of Intervention in the Right Ventricular Outflow Tract: Native RVOT, Conduits, and Bioprosthetic Valves

This consensus document for the performance of cardiovascular computed tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital heart disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons, and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multimodality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Technical Recommendations for Computed Tomography Guidance of Intervention in the Right Ventricular Outflow Tract: Native RVOT, Conduits and Bioprosthetic Valves: A White Paper of the Society of Cardiovascular Computed Tomography (SCCT), Congenital Heart Surgeons' Society (CHSS), and Society for Cardiovascular Angiography & Interventions (SCAI)

This consensus document for the performance of cardiovascular computed tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multi-modality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Childhood Obesity and Congenital Heart Disease: A Lifelong Struggle

Congenital heart disease (CHD) affects approximately one in every one hundred infants worldwide, making it one of the most prevalent birth abnormalities globally. Despite advances in medical technology and treatment choices, CHD remains a significant health issue and necessitates specialized care throughout an individual's life. Childhood obesity has emerged as a novel global epidemic, becoming a major public health issue, particularly in individuals with lifelong conditions such as CHD. Obesity has profound effects on cardiac hemodynamics and morphology, emphasizing the importance of addressing obesity as a significant risk factor for cardiovascular health. Obesity-induced alterations in cardiac function can have significant implications for cardiovascular health and may contribute to the increased risk of heart-related complications in obese individuals. Moreover, while diastolic dysfunction may be less apparent in obese children compared to adults, certain parameters do indicate changes in early left ventricular relaxation, suggesting that obesity can cause cardiac dysfunction even in pediatric populations. As most children with CHD now survive into adulthood, there is also concern about environmental and behavioral health risk factors in this particular patient group. Addressing obesity in individuals with CHD is essential to optimize their cardiovascular health and overall quality of life. This review aims to succinctly present the data on the impact of obesity on CHD and to enhance awareness of this perilous association among patients, families, and healthcare providers.

Obesity in Pediatric Congenital Heart Disease: The Role of Age, Complexity, and Sociodemographics

The prevalence of obesity in children with congenital heart disease (CHD) is greater than 25%, putting these patients at-risk for increased surgical morbidity and mortality. Our goal was to determine the association between CHD complexity, sociodemographic factors, and obesity. Our hypothesis was that among CHD patients, the odds of obesity would be highest in older children with simple CHD, and in all children with a lower socioeconomic status. We conducted a retrospective cohort study, reviewing electronic medical records of children aged 2-17 years from over 50 outpatient pediatric clinics in Houston, TX. Children were classified as simple or moderate/complex CHD, and obesity was defined by BMI ≥ 95th percentile for age and sex. Logistic regression was used to determine the association between sociodemographic factors and CHD complexity with obesity. We identified 648 CHD and 369,776 non-CHD patients. Children with simple CHD had a similar odds of obesity as non-CHD children. Children with CHD had a higher prevalence of obesity if they were older, male, Black, Hispanic, and publicly insured. Children with moderate/complex CHD had lower odds of obesity [OR 0.24 (95% CI 0.07-0.73)], however their predicted probability of obesity approached that of the general population as they aged. Additionally, there was an incremental relationship with poverty and obesity [1.01 (1.01-1.01)]. Awareness of which patients with CHD are at highest risk of obesity may help in targeting interventions to assist at-risk patients maintain a healthy lifestyle.

Pediatric Cardiac Magnetic Resonance Reference Values for Biventricular Volumes Derived From Different Contouring Techniques

BACKGROUND

Measurement of ventricular volumes and function using MRI is an important tool in pediatric congenital heart disease. However, normal values for children are sparce and analysis methods are inconsistent.

PURPOSE

To propose biventricular reference values in children for two MRI postprocessing (contouring) techniques.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 154 children from two institutions (13.9 ± 2.8 years; 101 male) that were referred for a clinical MRI study.

FIELD STRENGTH/SEQUENCE

1.5 T; balanced steady-state free precession (bSSFP) sequence.

ASSESSMENT

Left ventricular (LV) and right ventricular (RV) end-diastolic and end-systolic volumes (LVEDV, LVESV, RVEDV, RVESV) and end-diastolic and end-systolic myocardial mass (LVEDMM, LVESMM, RVEDMM, RVESMM) were measured from short-axis images using two contouring techniques: 1) papillary muscles, trabeculations and the moderator band were included in the ventricular blood volume and excluded from the myocardial mass, 2) papillary muscles, trabeculations and the moderator band were excluded from the ventricular volume and included in the ventricular mass.

STATISTICAL TESTS

Univariable and multivariable linear regression models were used to evaluate relationships between sex, weight, height, body surface area (BSA) and age and volumetric results. Reference graphs and tables were created with the LMS-method. Contouring techniques were compared by intraclass correlation, regression analysis and Bland-Altman plots. A P value < 0.05 was considered statistically significant.

RESULTS

Height and BSA were significantly associated with LVESV (method 1) and with LVEDV and RVEDV (method 2). LVESV (method 2), RVESV (both methods), RVEDV (method 1), and LVEDMM and RVEDMM (both methods), showed significant associations with height and weight. LVSV and RVSV (both methods) were significantly associated with BSA and weight. RVESV (method 1) was significantly associated with age. Gender showed significant associations for all parameters.

DATA CONCLUSION

The proposed pediatric reference values can be used in the diagnosis and follow-up of congenital or acquired heart disease and for research purposes.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Filling the gap between the heart and the body in acromegaly: a case-control study

OBJECTIVE

Cardiovascul diseases are the most common comorbidities in acromegaly. Potential parameters in pathology of cardiovascular comorbidities are changes in levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) as well as body composition parameters.

PURPOSE

The aim of this study was to examine morphological and functional parameters of the cardiovascular system by echocardiography and to assess its relationship with disease activity and body composition parameters.

METHODS

We prospectively enroled 129 acromegalic patients (82 females, 47 males) and 80 healthy controls (53 females, 27 males) matched for age, gender, and BMI. All patients underwent two-dimensional echocardiography. Body composition parameters were assessed by dual-energy X-ray absorptiometry.

RESULTS

Acromegaly patients presented with higher left ventricle mass (LVM) compared to controls (LVMI: 123 ± 45 g/m² vs 83 ± 16 g/m², P < 0.001). Prevalence of left ventricle hypertrophy in acromegaly patients was 67% (78% concentric, 22% eccentric). IGF -1 levels, BMI, and lean mass positively correlated with LVM in all acromegaly patients (P < 0.001). Fat mass positively correlated with LVM in females (R = 0.306, P = 0.005), but this correlation was not found in males. We did not find any difference in size of the left and right ventricle between acromegaly patients and controls. Acromegaly patients presented with left atrium enlargement, diastolic dysfunction and low incidence of systolic dysfunction. Valvopathy was found in 43% of patients with predominant (31%) prevalence of mitral regurgitation.

CONCLUSION

Our study demonstrates higher prevalence of cardiovascular comorbidities in acromegaly patients and the impact of IGF-1 levels and body composition parameters in pathology in some of these comorbidities.

Reference Values for Pediatric Atrial Volumes Assessed by Steady-State Free-Precession Magnetic Resonance Imaging Using Monoplane and Biplane Area-Length Methods

BACKGROUND

Measurement of atrial volumes by MRI is becoming increasingly important in pediatric cardiac disorders. However, MRI normal values for atrial volumes in children are lacking.

PURPOSE

To establish pediatric reference values for atrial volumes.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 155 healthy children from two large institutions (103 male, age 13.9 ± 2.8 years, range 4-18 years).

FIELD STRENGTH/SEQUENCE

A 1.5 T; balanced steady-state free precession (bSSFP) sequence.

ASSESSMENT

The monoplane and biplane area-length methods were used to measure minimal and maximal left and right atrial volumes (LAmin , LAmax , RAmin , and RAmax ) from four-chamber (4ch) and two-chamber (2ch) MR cine images. Centile charts and tables for atrial volumes were created.

STATISTICAL TESTS

Descriptive statistics, lambda-mu-sigma (LMS)-method of Cole and Green, univariable and multivariable linear regression models. A P value < 0.05 was considered to be statistically significant.

RESULTS

In the multivariable linear model, body surface area was significantly associated with all atrial volumes and sex was significantly associated with RA volumes, LA volumes measured in the 2ch-view as well as biplane LAmax. Average atrial volumes measured: monoplane 4ch: LAmin 13.1 ± 4.8 mL/m2 , LAmax 33.4 ± 8.8 mL/m2 , RAmin 18.5 ± 6.8 mL/m2 , RAmax 33.2 ± 9.6 mL/m2 ; monoplane 2ch: LAmin 12.7 ± 4.9 mL/m2 , LAmax 30.5 ± 9.5 mL/m2 ; biplane: LAmin 12.3 ± 4.5 mL/m2 , LAmax 30.9 ± 8.7 mL/m2 .

DATA CONCLUSION

Pediatric MRI reference values for atrial volumes have been provided.

TECHNICAL EFFICACY

2 EVIDENCE LEVEL: 4.

Making every contact count: recognising obesity in paediatric and young adult cardiology

INTRODUCTION

With increased survival, children with CHD are reaching adulthood, however, obesity amongst this cohort is an emerging problem. Making every contact count encourages clinicians to utilise contact to elicit behaviour change. The aim of this work was to identify whether the body habitus of children classified as obese was addressed during a clinical review.

METHODS

A retrospective observational cohort study was completed using a cardiology outpatient dataset from 2010 to 2019. Inclusion criteria are all children with a body mass index z score classified as obese (≥ 2 z scores). Individual electronic patient records were reviewed to identify long-term anthropometric measures including (i) recognition of body habitus, (ii) prescription of physical activity or dietary intervention, and (iii) referral to a weight management programme or dietitian.

RESULTS

From the cohort of 95 patients, 285 "obese clinical encounters" were identified, at the time of a cardiology clinic attendance. Of those, obesity was acknowledged in 25 clinic letters (8.65%), but only 8 used the correct terms "obese" or "obesity" (2.77%). Action to tackle obesity was recorded in 9.3% of cases with a direct referral to a dietitian being made on 3 occasions (1.04%).

CONCLUSIONS

Body habitus is not being routinely addressed by cardiologists caring for paediatric and young adult cardiac patients. This study has recognised an alarmingly high incidence of missed opportunities to make every contact count, to manage those with obesity and associated risk factors.

Heart failure in adult congenital heart disease: tetralogy of Fallot

The number of rTOF patients who survive into adulthood is steadily rising, with currently more than 90% reaching the third decade of life. However, rTOF patients are not cured, but rather have a lifelong increased risk for cardiac and non-cardiac complications. Heart failure is recognized as a significant complication. Its occurrence is strongly associated with adverse outcome. Unfortunately, conventional concepts of heart failure may not be directly applicable in this patient group. This article presents a review of the current knowledge on HF in rTOF patients, including incidence and prevalence, the most common mechanisms of heart failure, i.e., valvular pathologies, shunt lesions, left atrial hypertension, primary left heart and right heart failure, arrhythmias, and coronary artery disease. In addition, we will review information regarding extracardiac complications, risk factors for the development of heart failure, clinical impact and prognosis, and assessment possibilities, particularly of the right ventricle, as well as management strategies. We explore potential future concepts that may stimulate further research into this field.

Reference Values for Ventricular Volumes and Pulmonary Artery Dimensions in Pediatric Patients with Transposition of the Great Arteries After Arterial Switch Operation

BACKGROUND

Pulmonary artery (PA) anatomy in patients with transposition of the great arteries (TGA) after arterial switch operation (ASO) with Lecompte manoeuvre is different compared to healthy subjects, and stenoses of the PA are common. Magnetic resonance imaging (MRI) is an excellent imaging modality to assess PA anatomy in TGA patients. However, disease-specific reference values for PA size are scarce.

PURPOSE

To establish disease-specific reference ranges for PA dimensions and for biventricular volumes and mass.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 69 pediatric patients with TGA after ASO (median age 12.6 years; range 5-17.8 years; 13 females and 56 males).

FIELD STRENGTH/SEQUENCE

3.0 T, steady-state free precession (SSFP) and gradient echo cine sequences and four-dimensional time-resolved magnetic resonance angiography with keyhole.

ASSESSMENT

Right and left PA (RPA, LPA) were each measured at three locations during its course around the aorta. Ventricular volumes, mass, and ejection fraction were measured from a stack of short axis cine images.

STATISTICAL TESTS

The lambda-mu-sigma (LMS) method of Cole and Green, univariate and multivariate linear models, and t-test.

RESULTS

Centile graphs and tables for PA dimensions, biventricular volumes, mass, and ejection fraction were created. Univariate linear analysis showed significant associations (P < 0.05) between body surface area (BSA), height, and weight with systolic MPA and RPA diameter. In multivariate linear analysis, only BSA remained a strong predictor for main PA and RPA diameters. For biventricular volumes, the univariate linear model revealed a strong influence of BSA, height, weight, and age (all P < 0.05). On multivariate linear analysis, only body height remained associated.

DATA CONCLUSION

Uni- and multivariate linear analyses showed a strong association between BSA and PA diameters, as well as between height and biventricular volumes, and therefore, centile tables and graphs are presented accordingly. Our data may improve MR image interpretation and may serve as a reference in future studies.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY STAGE: 2.

Negative Impact of Obesity on Ventricular Size and Function and Exercise Performance in Children and Adolescents With Repaired Tetralogy of Fallot

BACKGROUND

Up to 25% of children with congenital heart disease are obese, which may have negative physiologic consequences for patients with repaired tetralogy of Fallot (rTOF).

METHODS

Patients with rTOF who underwent cardiac magnetic resonance (CMR) imaging and cardiopulmonary exercise testing from 2007 to 2018 were reviewed. Complex rTOF patients were excluded. Obese patients (body mass index [BMI] ≥ 95th percentile) were compared with normal-weight patients (BMI < 85th percentile). CMR data were indexed to actual body surface area (aBSA), height, and BSA assuming ideal body weight (iBSA).

RESULTS

We compared 32 obese patients matched with 64 normal-weight patients. Obese vs normal-weight patients had significantly lower right (RV; median 45% [interquartile range 42%-48%] vs 52% [47%-55%]; P < 0.0001) and left (LV; 52% [47%-56%] vs 56% [54%-60%]; P < 0.0001) ventricular ejection fractions (EFs). There were no statistically significant differences regarding aBSA-indexed volumes of the RV or LV at either end-diastole (EDV) or end-systole (ESV). However, when indexed to either height or iBSA, obese patients had significantly greater RVEDV and LVEDV, greater LV mass, and higher RV and LV stroke volumes. Obese patients had lower peak oxygen consumption and oxygen consumption at anaerobic threshold. These results did not change after adjusting for degree of pulmonary regurgitation.

CONCLUSIONS

Obesity is associated with increased biventricular size, decreased biventricular EFs, and impaired exercise performance after rTOF. These data suggest a potential role for cardiac rehabilitation for weight management and to optimize fitness.

Lean body mass is the strongest anthropometric predictor of left ventricular mass in the obese paediatric population

BACKGROUND

Indexing left ventricular mass to body surface area or height2.7 leads to inaccuracies in diagnosing left ventricular hypertrophy in obese children. Lean body mass predictive equations provide the opportunity to determine the utility of lean body mass in indexing left ventricular mass. Our objectives were to compare the diagnostic accuracy of predicted lean body mass, body surface area, and height in detecting abnormal left ventricle mass in obese children.

METHODS

Obese non-hypertensive patients aged 4-21 years were recruited prospectively. Dual-energy X-ray absorptiometry was used to measure lean body mass. Height, weight, sex, race, and body mass index z-score were used to calculate predicted lean body mass.

RESULTS

We enrolled 328 patients. Average age was 12.6 ± 3.8 years. Measured lean body mass had the strongest relationship with left ventricular mass (R2 = 0.84, p < 0.01) compared to predicted lean body mass (R2 = 0.82, p < 0.01), body surface area (R2 = 0.80, p < 0.01), and height2.7 (R2 = 0.65, p < 0.01). Of the clinically derived variables, predicted lean body mass was the only measure to have an independent association with left ventricular mass (β = 0.90, p < 0.01). Predicted lean body mass was the most accurate scaling variable in detecting left ventricular hypertrophy (positive predictive value = 88%, negative predictive value = 99%).

CONCLUSIONS

Lean body mass is the strongest predictor of left ventricular mass in obese children. Predicted lean body mass is the most accurate anthropometric scaling variable for left ventricular mass in left ventricular hypertrophy detection. Predicted lean body mass should be considered for clinical use as the body size correcting variable for left ventricular mass in obese children.

Cardiometabolic risk in obese children

Obesity in childhood remains a significant and prevalent public health concern. Excess adiposity in youth is a marker of increased cardiometabolic risk (CMR) in adolescents and adults. Several longitudinal studies confirm the strong association of pediatric obesity with the persistence of adult obesity and the future development of cardiovascular disease, diabetes, and increased risk of death. The economic and social impact of childhood obesity is further exacerbated by the early onset of the chronic disease burden in young adults during their peak productivity years. Furthermore, rising prevalence rates of severe obesity in youth from disadvantaged and/or minority backgrounds have prompted the creation of additional classification schemes for severe obesity to improve CMR stratification. Current guidelines focus on primary obesity prevention efforts, as well as screening for clustering of multiple CMR factors to target interventions. This review summarizes the scope of the pediatric obesity epidemic, the new severe obesity classification scheme, and examines the association of excess adiposity with cardiovascular and metabolic risk. We will also discuss potential questions for future investigation.

Effect of Weight Extremes on Ventricular Volumes and Myocardial Strain in Repaired Tetralogy of Fallot as Measured by CMR

Pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot (rTOF-TAP) is often based on cardiac MRI (CMR) right ventricular (RV) volumes indexed to body surface area (BSA). Weight extremes result in increased patient morbidity and affect indexed measurements. We hypothesized that patients with rTOF-TAP at extremes of weight have (1) over- or underestimated indexed volumes and (2) altered parameters of cardiac function. CMRs in patients with rTOF-TAP were retrospectively reviewed; analysis included right and left ventricular (LV) volumes and ejection fractions (EF) and peak global LV circumferential strain (ε _cc) from myocardial tagged images. Indexed volumes were recalculated using ideal BSA. Weight categories were assigned: underweight, appropriate weight, overweight, and obese. Linear regression models with weight category, spline of age, and gender were created to assess the association of weight and parameters of volume and function. When RV volumes were corrected for ideal BSA, 11 (31%) additional overweight and obese patients met published criteria for PVR and 3 (38%) underweight patients no longer met criteria. Obese and overweight patients had larger absolute LV and RV diastolic volumes, but no difference in volumes indexed to ideal BSA. Modeling demonstrated no difference in LVEF or RVEF by weight categories but significant differences in global LV ε _cc. Extremes of body weight may result in inappropriate timing of PVR. Extremes of weight lead to abnormalities in global LV ε _cc. Although clinical implications of abnormal ε _cc are unclear, these patients may be at higher risk for early ventricular dysfunction.

Normalization of glomerular filtration rate in obese children

BACKGROUND

Glomerular filtration rate (GFR) is conventionally indexed to body surface area (BSA), but this may lead to biased results when applied to subjects of abnormal body size. The aim of our study was to examine the impact of normalization to the BSA and alternative body size descriptors on measured and estimated GFR in overweight and obese children.

METHODS

This was a cross-sectional study of 313 children aged 8-9 years old. GFR was measured by 24-h creatinine clearance (CrCl) and additionally estimated from serum creatinine and cystatin C (CysC) using the combined Zappitelli formula, both as absolute values and adjusted to various body size descriptors. The results were compared between 163 normal-weight, 89 overweight and 61 obese children.

RESULTS

Compared to the normal-weight children, mean absolute GFR (both measured and estimated) was higher in the overweight and obese children, whereas BSA-adjusted GFR was lower. Linear regression models fitted in normal-weight children revealed equally close associations between absolute GFR and squared height, ideal body weight (IBW) and BSA derived from IBW. Normalization of GFR to the IBW-derived BSA completely eliminated the discrepancy between absolute and BSA-indexed GFR in overweight and obese children.

CONCLUSIONS

Indexing of GFR to BSA calculated from the ideal-rather than actual-body weight is a promising approach to avoid overcorrection when studying obese children. Further studies should assess the accuracy of this approach across the full range of age and BMI distribution.

High Overweight and Obesity in Fontan Patients: A 20-Year History

The prevalence of obesity in long-term survivors with complex congenital heart disease may be increasing, and little is known about the timing and onset of weight gain and growth patterns in these high-risk patients. Prevalence rates of overweight/obesity and longitudinal changes in body mass index (BMI) with age were determined in 606 patients with Fontan circulation seen at a tertiary care cardiology center from 1992 to 2012. The number of clinic encounters (n) was stratified by age group (n = 401, 2-5 years; n = 333, 6-11 years; n = 217, 12-19 years; and n = 129, >20 years). Among adults, 39% were overweight/obese at last clinic visit; 22% overweight, and 17% obese. Childhood anthropometric data were available for 82 adults, of which 15% (n = 12/82) were overweight/obese in childhood. The likelihood of being overweight/obese as an adult was three times higher if there was a BMI ≥ 85th percentile in childhood (CI 2.1-4.5, P < 0.01). Overweight/obesity in adulthood was associated with lower heart failure rates (4 vs. 19%, P = 0.03). Pediatric rates of overweight/obesity were comparable to national data (NHANES 2011-2012) in every age group: at 2-5 years, (25 vs. 23%), 6-11 years (26 vs. 34%), and 12-19 years (15 vs. 35%). Systolic blood pressure was higher in overweight/obese children as young as 2-5 years of age. Childhood and adult survivors with Fontan circulation have high rates of overweight/obesity. Childhood obesity is a strong predictor of future adiposity and is linked to changes in systolic blood pressure at a very young age.

Growth and Obesity Among Older Single Ventricle Patients Presenting for Fontan Conversion

INTRODUCTION

Long-term growth outcomes and the prevalence of obesity among older single ventricle (SV) patients have not been well characterized. We investigated these parameters, as well as the impact of obesity on survival, in an older cohort of SV patients presenting for Fontan conversion.

METHODS

We analyzed preoperative height, weight, and body mass index (BMI) of patients who underwent Fontan conversion. Overweight and obese were defined as BMI ≥85 percentile and ≥95 percentile for patients <20 years and BMI 25 to 30 kg/m(2) and ≥30 kg/m(2) for patients ≥20 years, respectively. Postoperative transplant-free survival was assessed among obese, overweight, and normal weight patients.

RESULTS

We evaluated 139 patients presenting for Fontan conversion at a median age of 23.2 years. Patients had shorter stature compared to the normal population (mean Z score -0.6, P < .001). Younger patients had lower BMI compared to the normal population (<20 years: mean Z score -0.5, P = .02), while older patients had elevated BMI (≥20 years: mean Z score +0.4, P < .001). The mean BMI among older patients approached overweight at 24.6 kg/m(2). The prevalence of obesity increased with advancing age, with 36% overweight and 14% obese at >30 years. At a median of 8.2 years following Fontan conversion, obesity and overweight status were not associated with transplant-free survival.

CONCLUSION

Older SV patients presenting for Fontan conversion had shorter stature compared to the normal population as well as a high prevalence of overweight and obesity. Although there was no relationship between weight status and early postoperative survival, further investigation of long-term outcomes is warranted.

Increased Body Mass Index Is Associated with Congestive Heart Failure and Mortality in Adult Fontan Patients

OBJECTIVE

Obesity affects adults with congenital heart disease (CHD). The effect of an increased body mass index (BMI) with respect to morbidity and mortality has not been evaluated in adults with complex CHD. Our objective was to evaluate the effects of increased BMI on heart failure and mortality in univentricular patients who had undergone Fontan palliation.

METHODS

A query of Fontan patients' first appointments at the Washington University Center for Adults with CHD between 2007 and 2014 yielded 79 patients. BMI status as normal (<25 kg/m(2) ), overweight (≥25, <30 kg/m(2) ), and obese (≥30 kg/m(2) ) was established at the patient's first appointment. We analyzed demographics, diuretic requirements, New York Heart Association (NYHA) class, and laboratory values using Student's two-sample t-test and Fisher's exact test. Mortality was assessed via survival curves, and hazard ratios were compiled with proportional hazard modeling.

RESULTS

The recent average BMI was significantly greater in patients with NYHA classes II-IV (29.3 ± 9 kg/m(2) ) compared with asymptomatic patients (24.8 ± 5.1 kg/m(2) , P = .006). Additionally, the average BMI of patients with a high diuretic requirement (≥40 mg/day IV furosemide equivalent) was obese, at 32.15 ± 9.1 kg/m(2) , compared with 25.91 ± 7.3 kg/m(2) for those on no or lower doses of diuretics (P = .009). Eighteen of the 79 patients met an endpoint of death, hospice placement, or cardiac transplant by the study conclusion. Kaplan-Meier analysis from time of first appointment until recent follow-up revealed a significant association between time to combined endpoint and BMI class. Cox proportional hazard modeling with age adjustment yielded a hazard ratio of 3.2 (95% CI 1.096-9.379) for obesity upon first presentation to an adult CHD clinic.

CONCLUSIONS

In patients with univentricular hearts and Fontan palliation, obesity is associated with symptomatic heart failure and mortality.

Repaired tetralogy of Fallot with coexisting unrepaired partial anomalous pulmonary venous connection is associated with diminished right ventricular ejection fraction and more severe right ventricular dilation

BACKGROUND

There is an established association between tetralogy of Fallot and partial anomalous pulmonary venous connections. This association is important because surgically repaired tetralogy patients have increased risk of right heart failure. We hypothesize that partial anomalous venous connections increase right ventricular volumes and worsen right ventricular failure.

MATERIALS AND METHODS

We reviewed cardiac MRI exams performed at a tertiary pediatric hospital from January 2005 to January 2014. We identified patients with repaired tetralogy and unrepaired partial anomalous pulmonary venous connection. We used age- and gender-matched repaired tetralogy patients without partial anomalous pulmonary venous connection as controls. We analyzed the MRI results and surgical course and performed comparative statistics to identify group differences.

RESULTS

There were eight patients with repaired tetralogy and unrepaired partial anomalous pulmonary venous connection and 16 controls. In all cases, the partial anomalous pulmonary venous connection was not detected on preoperative echocardiography. There were no significant differences in surgical course and body surface area between the two groups. Repaired tetralogy patients with unrepaired partial anomalous pulmonary venous connection showed significantly higher indexed right ventricular end diastolic volume (149 ± 33 mL/m(2) vs. 118 ± 30 mL/m(2)), right ventricle to left ventricle size ratios (3.1 ± 1.3 vs. 1.9 ± 0.5) and a higher incidence of reduced right ventricular ejection fraction compared to controls (3/8 vs. 0/16).

CONCLUSION

Repaired tetralogy of Fallot with unrepaired partial anomalous pulmonary venous connection is associated with reduced right ventricular ejection fraction and more significant right ventricular dilation.

The Cardiovascular Effects of Obesity on Ventricular Function and Mass in Patients after Tetralogy of Fallot Repair

OBJECTIVES

To determine the cardiovascular effects of obesity on patients with tetralogy of Fallot (TOF) repair.

STUDY DESIGN

Ventricular performance measures were compared between obese (body mass index [BMI] ≥95%), overweight (85% ≤BMI <95%), and normal weight subjects (BMI <85%) in a retrospective review of patients with TOF who underwent cardiac magnetic resonance from 2005-2010. Significance was P < .05.

RESULTS

Of 260 consecutive patients with TOF, 32 were obese (12.3%), 48 were overweight (18.5%), and 180 were normal weight (69.2%). Biventricular mass was increased in obese compared with normal weight patients with right ventricular mass more affected than left ventricular mass. Obese patients demonstrated decreased biventricular end-diastolic volume (EDV) and stroke volume (SV) when indexed to body surface area (BSA) with an increased heart rate when compared with normal weight patients; cardiac index, ejection fraction, and pulmonary regurgitation fraction were similar. When indexed to ideal BSA, biventricular EDV and SV were similar. EDV and SV for overweight patients were nearly identical to normal weight patients with ventricular mass in between the other 2 groups.

CONCLUSIONS

Approximately 12% of patients after TOF repair referred for cardiac magnetic resonance in a tertiary referral center are obese with increased biventricular mass. Obese patients and normal weight patients have similar cardiac indices, however, when indexed to actual BSA, obese patients demonstrate decreased EDV and SV with increased heart rate and similar cardiac indices. When indexed to ideal BSA, no differences in biventricular volumes were noted.