Somatic growth failure after the Fontan operation

Lead Longevity in Pediatric and Congenital Heart Disease Patients: The Impact of Patient Somatic Growth

BACKGROUND

Pacemakers and implantable cardioverter-defibrillators in pediatric and congenital heart disease (CHD) patients may be required for decades. In this population, there are sparse data on long-term lead functionality.

OBJECTIVES

The aims of this study were to assess pacemaker and defibrillator lead survival in pediatric and CHD patients beyond 10 years after implantation and to identify patient- and lead-related factors associated with earlier lead failure.

METHODS

This was a retrospective study reviewing all patients with a pacemaker or defibrillator who received care at a single large children's hospital during a 30-year timespan. The log-rank test and Cox proportional hazards model were used to identify risk factors associated with earlier lead failure.

RESULTS

Data were collected from 952 leads in 396 patients. Overall lead survival was 87% at 10 years, 78% at 15 years, and 69% at 20 years. Male sex, younger patient age, greater somatic growth, left ventricular lead location, and epicardial implantation approach were associated with higher likelihood of lead failure (log-rank test P <0.05). On multivariate analysis, the most significant predictor of lead failure was patient somatic growth ≥5 cm/year (HR 3.33; 95% CI: 1.78-6.25). The presence of CHD, lead insulation, and lead manufacturer had no impact on lead longevity.

CONCLUSIONS

Greater patient somatic growth is an important predictor of lead failure. Greater somatic growth may account for the observation in this study (and prior studies) that leads in male patients, younger patients, and implanted via epicardial approach were more likely to fail.

Somatic growth in single ventricle patients: A systematic review and meta-analysis

AIM

To map somatic growth patterns throughout Fontan palliation and summarise evidence on its key modifiers.

METHODS

Databases were searched for relevant articles published from January 2000 to December 2021. Height and weight z scores at each time point (birth, Glenn procedure, Fontan procedure and >5 years after Fontan completion) were pooled using a random effects meta-analysis. A random effects meta-regression model was fitted to model the trend in z scores over time.

RESULTS

Nineteen studies fulfilled eligibility criteria, yielding a total of 2006 participants. The z scores for height and weight were markedly reduced from birth to the interstage period, but recovered by about 50% following the Glenn procedure. At >10 years after the Fontan procedure, the z scores for weight seemed to normalise despite persistent lower height, resulting in increased body mass index. The review revealed a number of modifiers of somatic growth, including aggressive nutritional management, timing of Glenn/Fontan, prompt resolution of complications and obesity prevention programmes in adolescence and adulthood.

CONCLUSION

This review mapped the somatic growth of single ventricle patients and summarised key modifiers that may be amendable to improvement. These data provide guidance on strategies to further optimise somatic growth in this population and may serve as a benchmark for clinical follow-up.

Nutritional Management of Patients with Fontan Circulation: A Potential for Improved Outcomes from Birth to Adulthood

Fontan circulation (FC) is a surgically achieved palliation state offered to patients affected by a wide variety of congenital heart defects (CHDs) that are grouped under the name of univentricular heart. The procedure includes three different surgical stages. Malnutrition is a matter of concern in any phase of life for these children, often leading to longer hospital stays, higher mortality rates, and a higher risk of adverse neurodevelopmental and growth outcomes. Notwithstanding the relevance of proper nutrition for this subset of patients, specific guidelines on the matter are lacking. In this review, we aim to analyze the role of an adequate form of nutritional support in patients with FC throughout the different stages of their lives, in order to provide a practical approach to appropriate nutritional management. Firstly, the burden of faltering growth in patients with univentricular heart is analyzed, focusing on the pathogenesis of malnutrition, its detection and evaluation. Secondly, we summarize the nutritional issues of each life phase of a Fontan patient from birth to adulthood. Finally, we highlight the challenges of nutritional management in patients with failing Fontan.

Pubertal status of children with congenital heart disease

BACKGROUND

CHD influences many aspects of life in affected individuals. Puberty, a major aspect of development, is a concern for patients and families.

OBJECTIVES

We investigated pubertal status in children and adolescents with CHD.

METHODS

Patients with CHD aged 6-18 were enrolled. Cardiac diagnoses were confirmed using history, examination, and paraclinical tools including echocardiography. An endocrinologist determined pubertal stages, and the second Tanner stages for pubarche (P2), thelarche (B2), and gonadarche (G2) were considered as the pubertal onset. A study with a large sample size on pubertal onset in a normal population was used for comparison.

RESULTS

Totally, 451 patients (228 girls and 223 boys) at a median (10th-90th percentile) age of 10.79 (8.02-14.28) years for the girls and 10.72 (8.05-14.03) years for the boys were enrolled. The median (10th-90th percentile) ages at B2 and P2 in the girls with CHD were 10.77 (9.55-12.68) and 10.53 (9.39-12.28) years, respectively, which were higher than the median ages of 9.74 (8.23-11.94) and 10.49 (8.86-12.17) years in the normal girls.The median (10th-90th percentile) ages at G2 and P2 in the boys with CHD were 11.04 (8.85-13.23) and 11.88 (9.78-13.46) years, correspondingly, which were higher than the median ages of 9.01 (6.00-11.84) and 10.34 (6.84-13.10) years in the normal boys.

CONCLUSIONS

Pubertal onset could be delayed in children with CHD when compared with the normal population.

Prevalence of Malnutrition in Children with Congenital Heart Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the global prevalence of malnutrition in children with congenital heart disease (CHD).

STUDY DESIGN

A systematic review and meta-analysis were performed. Web of Science, PubMed, Embase, Wanfang Database, China National Knowledge Infrastructure, and China Biology Medicine disc databases were searched for studies published through April 2021. Random-effect model meta-analyses were performed to derive the pooled the prevalence of preoperative underweight, stunting, and wasting in children with CHD. Time-trend analyses of postoperative malnutrition prevalence were undertaken. Subgroup and sensitivity analyses were conducted to explore sources of heterogeneity. Egger test and funnel plots were used to explore public bias.

RESULTS

A total of 39 studies were included in this meta-analysis. The pooled estimates of preoperative malnutrition in children with CHD were 27.4% (95% CI, 21.7-34.0) for underweight, 24.4% (95% CI, 19.5-30.0) for stunting, and 24.8% (95% CI, 19.3-31.3) for wasting. Catch-up growth was found in the postoperative period among some children. Different continents were identified as heterogeneity moderators by subgroup analyses.

CONCLUSIONS

Children with CHD have a high prevalence of preoperative malnutrition and some show catch-up growth postoperatively. These data can be used as benchmarks in efforts to improve the nutritional status of children with CHD.

Deficits in the Functional Muscle-Bone Unit in Youths with Fontan Physiology

OBJECTIVE

To determine whether dual energy X-ray absorptiometry (DXA), a clinically available tool, mirrors the magnitude of deficits in trabecular and cortical bone mineral density (BMD) demonstrated on peripheral quantitative computed tomography in youth with Fontan physiology.

STUDY DESIGN

We aimed to describe DXA-derived BMD at multiple sites and to investigate the relationship between BMD and leg lean mass, a surrogate for skeletal muscle loading. Subjects with Fontan (n = 46; aged 5-20 years) underwent DXA in a cross-sectional study of growth and bone and muscle health as described previously. Data from the Bone Mineral Density in Childhood Study were used to calculate age-, sex-, and race-specific BMD z-scores of the whole body, lumbar spine, hip, femoral neck, distal one-third radius, ultradistal radius, and leg lean mass z-score (LLMZ).

RESULTS

Fontan BMD z-scores were significantly lower than reference at all sites-whole body, -0.34 ± 0.85 (P = .01); spine, -0.41 ± 0.96 (P = .008); hip, -0.75 ± 1.1 (P < .001); femoral neck, -0.73 ± 1.0 (P < .001); distal one-third radius, -0.87 ± 1.1 (P < .001); and ultradistal radius. -0.92 ± 1.03 (P < .001)-as was LLMZ (-0.93 ± 1.1; P < .001). Lower LLMZ was associated with lower BMD of the whole body (R² = 0.40; P < .001), lumbar spine (R² = 0.16; P = .005), total hip (R² = 0.32; P < .001), femoral neck (R² = 0.47; P < .001), and ultradistal radius (R² = 0.35; P < .001).

CONCLUSIONS

Patients with Fontan have marked deficits in both cortical (hip, distal one-third radius) and trabecular (lumbar spine, femoral neck, ultradistal radius) BMD. Lower LLMZ is associated with lower BMD and may reflect inadequate skeletal muscle loading. Interventions to increase muscle mass may improve bone accrual.

Sizing Up Fontan Failure: Association with Increasing Weight in Adulthood

Obesity has become increasingly recognized in adults with Fontan palliation, yet the relationship between weight changes in adulthood and Fontan failure is not clearly defined. We hypothesize that increasing weight in adulthood among Fontan patients is associated with the development of Fontan failure. Single-center data from adults with Fontan palliation who were not in Fontan failure at their first clinic visit in adulthood and who received ongoing care were retrospectively collected. Fontan failure was defined as death, transplant, diagnosis of protein losing enteropathy, predicted peak VO₂ less than 50%, or new loop diuretic requirement. Anthropometric data including weight and BMI were collected. Change in weight was compared between those that developed Fontan failure, and those that remained failure-free. To estimate the association between weight change during adulthood and the risk of developing Fontan failure, a survival analysis using multiple Cox's proportional hazards regression model was performed. Overall, 104 patients were included in the analysis. Those that developed Fontan failure had a larger associated median weight gain than those who remained failure-free (7.8 kg vs. 4.9 kg, respectively; p = 0.011). In multivariable Cox regression analysis, increased weight during adulthood was associated with increased likelihood of developing Fontan failure (HR 1.36; CI 1.07-1.73; p = 0.011). Weight gain in adulthood is associated with the development of Fontan failure.

Growth in Children with a Fontan Circulation

OBJECTIVE

To evaluate growth in a population of patients with Fontan circulation.

STUDY DESIGN

We performed a cross-sectional evaluation of patients followed in our multidisciplinary Fontan clinic from January 2011 through August 2015. We reviewed the historical data, anthropometry, clinical, and laboratory studies and performed bivariate and multivariate analysis of factors associated with height z score.

RESULTS

Patients (n = 210) were included in the study at median age 11.07 years (8.3, 14.73 years) (43% female); 138 (65%) had a dominant right systemic ventricle and 92 (44%) hypoplastic left heart syndrome. Median age at completion of Fontan circulation was 31 months (7.6, 135.8 months). Median height z score was -0.58 (-1.75, 0.26). Twenty-five (12%) had current or past history of protein-losing enteropathy (PLE). Median height z score for those with current or past history of PLE was -2.1 (-2.46, 1.24). Multivariate analysis revealed positive associations between height z score and body mass index z score, time since Fontan, mid-parental height, dominant systemic ventricle type, and serum alkaline phosphatase. Height correlated negatively with known genetic syndrome, PLE, use of stimulant or oral steroid medication.

CONCLUSIONS

Children with Fontan circulation have mild deficits in height, with greater deficits in those with PLE. Height z score improves with time postsurgery. Improving weight, leading to improved body mass index, may be a modifiable factor that improves growth in those who are underweight. Biochemical markers may be helpful screening tests for high-risk groups in whom to intensify interventions.

Somatic growth in children with congenital heart disease at 10 years of age: Risk factors and longitudinal growth

BACKGROUND

Children with congenital heart disease (CHD) are at risk of impaired growth.

AIMS

To describe height, weight, head circumference (HC), and body mass index (BMI) at 10 years and identify risk factors for altered longitudinal growth in children with CHD.

STUDY DESIGN

Growth parameters were evaluated from birth until 10 years using z-scores. The impact of cardiac and noncardiac factors on longitudinal growth was investigated.

SUBJECTS

A total of 135 children with different types of CHD who underwent cardiopulmonary bypass surgery, no genetic disorder.

OUTCOME MEASURES

Head circumference, weight, height and BMI.

RESULTS

At 10 years, z-scores for height and BMI did not differ from the Swiss population (P > 0.1). Z-scores for weight and HC were significantly below the norm (-0.38 and - 0.71, P < 0.01). From 1 to 10 years, all growth parameters except BMI increased significantly (P ≤ 0.001, BMI: P = 0.14). Lower gestational age and longer length of hospitalization were associated with either impaired head circumference or length at 10 years, while lower socioeconomic status was associated with higher BMI and weight at 10 years (all P < 0.05).

CONCLUSION

Despite partial catch-up, somatic growth remains impaired in children with CHD with weight and HC below the norm at 10 years. The only cardiac factor associated with impaired longitudinal growth was duration of hospital stay. Furthermore, lower socioeconomic background may pose a risk of overweight at older age. Close monitoring of growth parameters and parental counselling in all CHD children is advisable beyond early childhood to ensure optimal somatic growth.

Serial assessment of somatic and cardiovascular development in patients with single ventricle undergoing Fontan procedure

BACKGROUND

The palliation of patients with single ventricle (SV) undergoing Fontan procedure led to improved long-term survival but is still limited due to cardiovascular complications. The aim of this study was to describe the somatic and cardiovascular development of Fontan patients until adolescence and to identify determining factors.

METHODS

We retrospectively assessed somatic growth, vascular growth of pulmonary arteries, and cardiac growth of the SV and systemic semilunar valve from 0 to 16 years of age using transthoracic echocardiography. The Doppler inflow pattern of the atrioventricular valve was quantified by E-, A-wave and E/A ratio. All data were converted to z-scores and analyzed using linear mixed effect models to identify associations with age at Fontan procedure, gender, and ventricular morphology.

RESULTS

134 patients undergoing Fontan procedure at a median age of 2.4 (IQR 2.12 to 2.8) years were analyzed. A catch-up of somatic growth after Fontan procedure until school age was found, with lower body height and weight z-scores in male patients and patients with systemic right ventricles. An early time of Fontan procedure was favorable for somatic growth, but not for vascular growth. Cardiac development indicated a decrease of SV end-diastolic diameter z-score until adolescence. Despite a trend towards normalization, E-wave and E/A ratio z-scores were diminished over the entire period.

CONCLUSIONS

There is a catch-up growth of somatic, vascular and cardiac parameters after Fontan procedure, which in our cohort depends on the time of Fontan procedure, ventricular morphology, and gender. Beside other factors, diastolic function of the SV remains altered.

Treatment strategies for protein-losing enteropathy in Fontan-palliated patients

OBJECTIVE

Protein-losing enteropathy is an infrequent but severe condition occurring after Fontan procedure. The multifactorial pathogenesis remains unclear and no single proposed treatment strategy has proven universally successful. Therefore, we sought to describe different treatment strategies and their effect on clinical outcome and mortality.

MATERIAL AND METHODS

We performed a retrospective observational study. From the total cohort of 439 Fontan patients treated in our institution during the study period 1986-2019, 30 patients (6.8%) with protein-losing enteropathy were identified. Perioperative, clinical, echocardiographic, laboratory, and invasive haemodynamic findings and treatment details were analysed.

RESULTS

Median follow-up after disease onset was 13.1 years [interquartile range 10.6]. Twenty-five patients received surgical or interventional treatment for haemodynamic restrictions. Medical treatment, predominantly pulmonary vasodilator and/or systemic anti-inflammatory therapy with budesonide, was initiated in 28 patients. In 15 patients, a stable remission could be achieved by medical or surgical procedures (n = 3 each), by combined multimodal therapy (n = 8), or ultimately by cardiac transplantation (n = 1). Phrenic palsy, bradyarrhythmia, Fontan pathway stenosis, and absence of a fenestration were significantly associated with development of protein-losing enteropathy (p = 0.001-0.48). Ten patients (33.3%) died during follow-up; 5-year survival estimate was 96.1%. In unadjusted analysis, medical therapy with budesonide and pulmonary vasodilator therapy in combination was associated with improved survival.

CONCLUSIONS

Protein-losing enteropathy is a serious condition limiting survival after the Fontan procedure. Comprehensive assessment and individual treatment strategies are mandatory to achieve best possible outcome. Nevertheless, relapse is frequent and long-term mortality substantial. Cardiac transplantation should be considered early as treatment option.

Growth stunting in single ventricle patients after heart transplantation

BACKGROUND

Malnutrition is common among children with single ventricle (SV) congenital heart disease (CHD). The impact of heart transplantation (HT) on nutritional status in SV patients is understudied. Our aim was to evaluate anthropometric changes in SV patients after HT, compared with those transplanted for cardiomyopathy (CM).

METHODS

We performed a single-center retrospective chart review of SV and CM patients < 18 years who underwent HT from January 01, 2010 to December 05, 2017. Wasting and stunting were defined as z-scores for weight-for-age or height-for-age ≤-2, respectively. Changes in these indices between HT and 3 years post-HT were analyzed.

RESULTS

Of 86 eligible patients, 28 (33%) had SV CHD and 58 (67%) had CM. Data were available at 3 years post-HT for 57 patients. At transplant, wasting was equally present in SV versus CM patients (7/28, 25% vs. 9/58, 16%, P = .22), which remained true at 3 years post-HT (2/16, 13% vs. 3/41, 7%, P = .61). At transplant, stunting was more common in SV than CM patients (17/28, 61% vs. 8/58, 14%, P < .001). At 3 years post-HT, 6 of 16 (38%) SV patients and 3 of 41 (7%) CM patients remained stunted (P = .01). Among all patients, wasting decreased from transplant to end-point (19% vs. 9%, P = .05), but stunting did not (29% vs. 16%, P = .2), such that wasting and stunting were associated at transplant (P < .001) but not at end-point (P = .17).

CONCLUSIONS

Longitudinal growth remains impaired for several years after HT in SV patients, even when weight gain is achieved, suggesting that some factors contributing to growth impairment persist despite resolution of SV physiology.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

Alkaline Phosphatase: A Biomarker of Cardiac Function in Pediatric Patients

Myocardial dysfunction and heart failure are common in pediatric patients with congenital and acquired heart disease. Alkaline phosphatase (AP) has been suggested as a biomarker for myocardial dysfunction after Fontan operation. We hypothesized that pediatric patients with myocardial dysfunction requiring orthotopic heart transplant (OHT) have diminished AP compared to normal. A retrospective review was performed in all patients who underwent OHT at Arkansas Children's Hospital between January 2007 and October 2012. Anatomic diagnoses, therapeutic interventions, and ventricular ejection fraction (EF) were recorded. Z scores for AP levels in the study group were determined by comparing the observed AP levels to age- and gender-matched normative values. T tests were performed to compare the mean AP Z score prior to and after OHT. p values <0.05 were considered statistically significant. During the study period, 124 OHTs were performed. Complete study data were available and analyzed from 71/124 patients (mean age at OHT 3.9 years; 51% female). The mean AP Z score was significantly lower in the study group prior to OHT compared to normal (p < 0.0001). The initiation of ACE inhibitor therapy prior to OHT was associated with a significant increase in AP and the ventricular EF (p < 0.001 for both). Treatment with milrinone was associated with an increase in EF. AP is significantly lower in pediatric patients with myocardial dysfunction prior to OHT compared to normal. AP increases significantly after the initiation of therapies to improve myocardial function. Diminished AP is an indicator of myocardial dysfunction in pediatric patients.

Assessment of Growth 6 Years after the Norwood Procedure

At 6 years of age, patients with hypoplastic left heart syndrome had mean age-adjusted z-scores for weight and height below the normative population, and body mass index was similar to the normative population. Males had the greatest increase in z-scores for body mass index.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00115934.

Interstage somatic growth in children with hypoplastic left heart syndrome after initial palliation with the hybrid procedure

Introduction The hybrid procedure is one mode of initial palliation for hypoplastic left heart syndrome. Subsequently, patients proceed with either the "three-stage" pathway - comprehensive second stage followed by Fontan completion - or the "four-stage" pathway - Norwood procedure, hemi-Fontan, or Fontan completion. In this study, we describe somatic growth patterns observed in the hybrid groups and a comparison primary Norwood group.

METHODS

A retrospective analysis of patients who have undergone hybrid procedure and Fontan completion was performed. Weight-for-age and height-for-age z-scores were recorded at each operation.

RESULTS

We identified 13 hybrid patients - eight in the three-stage pathway and five in the four-stage pathway - and 49 Norwood patients. Weight: three stage: weight decreased from hybrid procedure to comprehensive second stage (-0.4±1.3 versus -2.3±1.4, p<0.01) and then increased to Fontan completion (-0.4±1.5 versus -0.6±1.4, p<0.01); four stage: weight decreased from hybrid procedure to Norwood (-2.0±1.4 versus -3.3±0.9, p=0.06), then stabilised to hemi-Fontan. Weight increased from hemi-Fontan to Fontan completion (-2.7±0.6 versus -1.0±0.7, p=0.01); primary Norwood group: weight decreased from Norwood to hemi-Fontan (p<0.001) and then increased to Fontan completion (p<0.001). Height: height declined from hybrid procedure to Fontan completion in the three-stage group. In the four-stage group, height decreased from hybrid to hemi-Fontan, and then increased to Fontan completion. The Norwood group decreased in height from Norwood to hemi-Fontan, followed by an increase to Fontan completion.

CONCLUSION

In this study, we show that patients undergoing the hybrid procedure have poor weight gain before superior cavopulmonary connection, before returning to baseline by Fontan completion. This study identifies key periods to target poor somatic growth, a risk factor of morbidity and worse neurodevelopmental outcomes.

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.

Deficits in bone density and structure in children and young adults following Fontan palliation

BACKGROUND

Survival of patients with congenital heart disease has improved such that there are now more adults than children living with these conditions. Complex single ventricle congenital heart disease requiring Fontan palliation is associated with multiple risk factors for impaired bone accrual. Bone density and structure have not been characterized in these patients.

METHODS

Tibia peripheral quantitative computed tomography (pQCT) was used to assess trabecular and cortical volumetric bone mineral density (vBMD), cortical dimensions, and calf muscle area in 43 Fontan participants (5-33 years old), a median of 10 years following Fontan palliation. pQCT outcomes were converted to sex- and race-specific Z-scores relative to age based on >700 healthy reference participants. Cortical dimensions and muscle area were further adjusted for tibia length.

RESULTS

Height Z-scores were lower in Fontan compared to reference participants (mean ± SD: -0.29 ± 1.00 vs. 0.25 ± 0.93, p < 0.001); BMI Z-scores were similar (0.16 ± 0.88 vs. 0.35 ± 1.02, p = 0.1). Fontan participants had lower trabecular vBMD Z-scores (-0.85 ± 0.96 vs. 0.01 ± 1.02, p < 0.001); cortical vBMD Z-scores were similar (-0.17 ± 0.98 vs. 0.00 ± 1.00, p = 0.27). Cortical dimensions were reduced with lower cortical area (-0.59 ± 0.84 vs. 0.00 ± 0.88, p<0.001) and periosteal circumference (-0.50 ± 0.82 vs. 0.00 ± 0.84, p < 0.001) Z-scores, compared to reference participants. Calf muscle area Z-scores were lower in the Fontan participants (-0.45 ± 0.98 vs. 0.00 ± 0.96, p = 0.003) and lower calf muscle area Z-scores were associated with smaller periosteal circumference Z-scores (R = 0.62, p < 0.001). Musculoskeletal deficits were not associated with age, Fontan characteristics, parathyroid hormone or vitamin D levels.

CONCLUSIONS

Children and young adults demonstrate low trabecular vBMD, cortical structure and muscle area following Fontan. Muscle deficits were associated with smaller periosteal dimensions. Future studies should determine the fracture implications of these deficits and identify interventions to promote musculoskeletal development.

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles

OBJECTIVE

Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle.

METHODS

106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3-9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was p<0.05.

RESULTS

A strong inverse correlation was noted between CBF and APC/shunt both on room air and with hypercarbia whether CBF was indexed to aortic flow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=-0.67--0.70 for all patients on room air, p<0.01 and R=-0.49--0.90 in hypercarbia, p<0.01). Correlations were not different between surgical stages. CBF was lower, and APCs/shunt flow was higher prior to BDG than in other stages.

CONCLUSIONS

There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory.

TRIAL REGISTRATION NUMBER

NCT02135081.

Cardiac regeneration in children

Very young mammals have an impressive cardiac regeneration capacity. In contrast, cardiac regeneration is very limited in adult humans. The hearts of young children have a higher regenerative capacity compared with adults, as, for example, seen after surgical correction of an anomalous left coronary artery arising from the pulmonary artery or in children with univentricular hearts, who present enormous morphological changes after volume unloading. In addition, the enormous regenerative potential of growing children's hearts is reflected in the spontaneous courses of children with severely deteriorated cardiac function (e.g., patients with dilated cardiomyopathy). The extent of this regenerative capacity and its time dependency remain to be elucidated in the future and should be exploited to improve the treatment of children with severe heart insufficiency.

Usefulness of insulin like growth factor 1 as a marker of heart failure in children and young adults after the Fontan palliation procedure

Growth hormone and its mediator, insulinlike growth factor 1 (IGF-1), are key determinants of growth in children and young adults. As patients with Fontan physiology often experience diminished longitudinal growth, we sought to describe IGF-1 levels in this population and to identify factors associated with IGF-1 deficiency. Forty-one Fontan subjects ≥5 years were evaluated in this cross-sectional study. Age- and gender-specific height Z scores were generated using national data. Laboratory testing included IGF-1 and brain natriuretic peptide (BNP) levels. IGF-1 levels were converted to age-, gender-, and Tanner stage-specific Z scores. BNP levels were log transformed to achieve a normal distribution (log-BNP). Medical records were reviewed for pertinent clinical variables. Predictors of IGF-1 Z score were assessed through the Student t test and Pearson's correlation. Median age was 11.1 years (range 5.1 to 33.5 years), and time from Fontan was 8.2 years (1.1 to 26.7). Mean height Z score was -0.2 ± 0.9 with a mean IGF-1 Z score of -0.1 ± 1.3. There was no association between IGF-1 Z score and height Z score. Longer interval since Fontan (R = -0.32, p = 0.04), higher log-BNP (R = -0.40; p = 0.01), and lower indexed systemic flow on cardiac magnetic resonance (R = 0.55, p = 0.02) were associated with lower IGF-1 Z scores. In conclusion, in this cohort with Fontan physiology, higher BNP and lower systemic flow were associated with lower IGF-1 Z score. Longitudinal studies are needed to determine if these relations represent a mechanistic explanation for diminished growth in children with this physiology and with other forms of congenital heart disease.

Are the children and adolescents with congenital heart disease living in Southwestern Ontario really overweight and obese?

OBJECTIVE

To assess the prevalence of overweight and obesity in children with congenital heart disease and compare them with age-matched healthy children in Southwestern Ontario, Canada.

METHODS

We compared the Center of Disease Control weight and body mass index z-scores of 1080 children, aged 2 to 18 years, who presented to our paediatric cardiology outpatient clinic from 2008 to 2010 for congenital heart disease with 1083 healthy controls.

RESULTS

In all, 18.2% of the children with congenital heart disease and 20.8% of healthy children were identified to be either overweight or obese. Overall, the weight category distribution had been similar between the congenital heart disease and healthy control groups, as well as between the congenital heart disease subgroups. There was no difference in normal weight and overweight/obese categories between children with congenital heart disease and healthy children. The underweight category, however, showed a significantly higher prevalence in congenital heart disease compared with healthy children (6.8 and 4.5%, respectively, p = 0.03).

CONCLUSION

The prevalence of overweight/obesity did not differ in children with congenital heart disease compared with age-matched healthy children; however, it is still high (18.2%). Obesity may represent an additional risk factor for the long-term cardiovascular health of congenital heart disease patients aside from the underlying heart defect.

Brain magnetic resonance immediately before surgery in single ventricles and surgical postponement

BACKGROUND

Single-ventricle patients undergoing surgical reconstruction experience a high rate of brain injury. Incidental findings on preoperative brain scans may result in safety considerations involving hemorrhage extension during cardiopulmonary bypass that result in surgical postponement.

METHODS

Single-ventricle patients were studied with brain scans immediately preoperatively, as part of a National Institutes of Health study, and were reviewed by neuroradiology immediately before cardiopulmonary bypass.

RESULTS

Of 144 consecutive patients recruited into the project, 33 were studied before stage I (3.7±1.8 days), 34 before bidirectional Glenn (5.8±0.5 months), and 67 before Fontan (3.3±1.1 years) operations. Six operations (4.5%), 2 before stage I, 3 before bidirectional Glenn, and 1 before Fontan, were postponed because of concerning findings on brain magnetic resonance imaging. Five were due to unexpected incidental findings of acute intracranial hemorrhage, and 1 was due to diffuse cerebellar cytotoxic edema; none who proceeded to operation had these lesions. Prematurity and genetic syndromes were not present in any patients with a postponed operation. Four of 4 before bidirectional Glenn/Fontan with surgical delays had hypoplastic left heart syndrome compared with 44 of 97 who did not (p=0.048). After observation and follow-up, all eventually had successful operations with bypass.

CONCLUSIONS

Preoperative brain magnetic resonance imaging performed in children with single ventricles disclosed injuries in 4.5% leading to surgical delay; hemorrhagic lesions were most common and raised concerns for extension during the operation. The true risk of progression and need for delay of the operation due to heparinization associated with these lesions remains uncertain.

Lean mass deficits, vitamin D status and exercise capacity in children and young adults after Fontan palliation

OBJECTIVE

We sought to evaluate body composition in children and young adults with Fontan physiology. Leg lean mass (LM) deficits correlate with diminished exercise capacity in other populations and may contribute to exercise limitations in this cohort.

METHODS

This cross-sectional study included whole body dual energy X-ray absorptiometry scans in 50 Fontan participants ≥5 years, and measures of peak oxygen consumption (VO2) in 28. Whole body and leg LM (a measure of skeletal muscle) were converted to sex- and race-specific Z-scores, relative to age and stature, based on 992 healthy reference participants.

RESULTS

Median age was 11.5 (range 5.1-33.5) years at 9.3 (1.1-26.7) years from Fontan. Height Z-scores were lower in Fontan compared with reference participants (-0.47±1.08 vs 0.25±0.93, p<0.0001). Body mass index Z-scores were similar (0.15±0.98 vs 0.35±1.02, p=0.18). LM Z-scores were lower in Fontan compared with reference participants (whole body LM -0.33±0.77 vs 0.00±0.74, p=0.003; leg LM -0.89±0.91 vs 0.00±0.89, p<0.0001). LM Z-scores were not associated with age or Fontan characteristics. Leg LM Z-scores were lower in vitamin D deficient versus sufficient Fontan participants (-1.47±0.63 vs -0.71±0.92, p=0.01). Median per cent predicted peak VO2 was 81% (range 13%-113%) and was associated with leg LM Z-scores (r=0.54, p=0.003).

CONCLUSIONS

Following Fontan, children and young adults are shorter than their peers and have significant LM deficits. Skeletal muscle deficits were associated with vitamin D deficiency and reduced exercise capacity. Future studies should examine the progression of these deficits to further understand the contribution of peripheral musculature to Fontan exercise capacity.

Feeding dysfunction in children with single ventricle following staged palliation

OBJECTIVE

To determine the prevalence of feeding dysfunction in children with single ventricle defects and identify associated risk factors.

STUDY DESIGN

Patients aged 2-6 years with single ventricle physiology presenting for routine cardiology follow-up at the Children's Hospital of Wisconsin were prospectively identified. Parents of the patients completed 2 validated instruments for assessment of feeding dysfunction. Chart review was performed to retrospectively obtain demographic and diagnostic data.

RESULTS

Instruments were completed for 56 patients; median age was 39 months. Overall, 28 (50%) patients had some form of feeding dysfunction. Compared with a normal reference population, patients with single ventricle had statistically significant differences in dysfunctional food manipulation (P < .001), mealtime aggression (P = .002), choking/gagging/vomiting (P < .001), resistance to eating (P < .001), and parental aversion to mealtime (P < .001). Weight and height for age z-scores were significantly lower in subjects with feeding dysfunction (-0.84 vs -0.33; P < .05 and -1.46 vs -0.56; P = .001, respectively). Multivariable analysis identified current gastrostomy tube use (P = .02) and a single parent household (P = .01) as risk factors for feeding dysfunction.

CONCLUSION

Feeding dysfunction is common in children with single ventricle defects, occurring in 50% of our cohort. Feeding dysfunction is associated with worse growth measures. Current gastrostomy tube use and a single parent household were identified as independent risk factors for feeding dysfunction.

Normal interstage growth after the norwood operation associated with interstage home monitoring

After stage 1 palliation (S1P) with a Norwood operation, infants commonly experience growth failure during the initial interstage period. Growth failure during this high-risk period is associated with worse outcomes. This study evaluated the growth patterns of patients enrolled in the authors' interstage home-monitoring program (HMP), which uses a multidisciplinary team approach to nutrition management. From 2000 to 2009, 148 infants were enrolled in the HMP after S1P. Families recorded daily weights during the interstage period and alerted the interstage monitoring team about protocol violations of nutritional goals. Interstage monitoring and inpatient data from the S1P hospitalization were reviewed to identify risk factors for poor growth. Growth outcomes were compared with published norms from the Centers for Disease Control. Interstage survival for patients in the HMP was 98 % (145/148). Growth velocity during the interstage period was 26 ± 8 g/day. The weight-for-age z-scores decreased from birth to discharge after S1P (-0.4 ± 0.9 to -1.3 ± 0.9; p < 0.001) but then increased during the interstage period to the time of S2P (-0.9 ± 1; p < 0.001). The factors associated with improved growth during the interstage period included male gender, greater birth weight, full oral feeding at S1P discharge, and a later birth era. After S1P, infants enrolled in an HMP experienced normal growth velocity during the interstage period. Daily observation of oxygen saturation, weight change, and enteral intake together with implementation of a multidisciplinary feeding protocol is associated with excellent interstage growth and survival.

Children with protein-losing enteropathy after the Fontan operation are at risk for abnormal bone mineral density

Protein-losing enteropathy (PLE) is a rare but potentially devastating complication of single-ventricle physiology after the Fontan operation. Although abnormal bone mineral density (BMD) is a known complication of chronic disease and congenital heart disease, no reports have described BMD in patients with PLE. This study investigated a cross-sectional sample of children and young adults with a confirmed diagnosis of PLE. Serum levels of 25(OH)D, calcium, total protein, and albumin were recorded from the first outpatient encounter with each subject. Corrected calcium (cCa) was calculated from the serum calcium and albumin levels. Dual-energy X-ray absorptiometry (DXA) was used to measure BMD, and z-scores were generated using appropriate software. DXA results were available for 12 patients (eight males and four females). The age at DXA ranged from 7.2 to 25.2 years. The mean z-score was -1.73 standard deviation (SD) for the entire cohort, with 42 % z-scores below -2 SDs. Serum 25(OH)D levels were abnormal in 58 % of the patients. There was a positive correlation between cCa and DXA z-score and a negative correlation between total protein and DXA z-score. Patients receiving corticosteroid therapy had a significantly lower DXA z-score than those not receiving corticosteroids (-3.15 vs. -0.31; p = 0.02). Children with PLE are at risk for abnormal BMD compared with age- and sex-matched control subjects. In the study cohort, corticosteroid exposure, a marker of disease severity, appeared to be associated with decreased BMD. Routine bone health screening is warranted for children with PLE, particularly those receiving corticosteroid therapy.

Sex and age differences in body-image, self-esteem, and body mass index in adolescents and adults after single-ventricle palliation

Single-ventricle congenital heart disease (SVCHD) requires multiple palliative surgical procedures that leave visible surgical scars and physical deficits, which can alter body-image and self-esteem. This study aimed to compare sex and age differences in body-image, self-esteem, and body mass index (BMI) in adolescents and adults with SVCHD after surgical palliation with those of a healthy control group. Using a comparative, cross-sectional design, 54 adolescent and adult (26 male and 28 female) patients, age 15–50 years, with SVCHD were compared with 66 age-matched healthy controls. Body-image and self-esteem were measured using the Multidimensional Body-Self Relations Questionnaire–Appearance Scale and Rosenberg Self-Esteem Scale. Height and weight were collected from retrospective chart review, and BMI was calculated. Female adolescents and adult patients with SVCHD reported lower body image compared with males patients with SVCHD and healthy controls (p = 0.003). Specific areas of concern were face (p = 0.002), upper torso or chest (p = 0.002), and muscle tone (p = 0.001). Patients with SVCHD who were \21 years of age had lower body image compared with healthy controls (p = 0.006). Self-esteem was comparable for both patients with SVCHD and healthy peers. There were no sex differences in BMI; BMI was higher in subjects[21 years of age (p = 0.01). Despite the similarities observed in self-esteem between the two groups, female patients with SVCHD\21 years of age reported lower perceived body-image. Our findings support the need to recognize poor psychological adjustment related to low self-esteem in patients with SVCHD; female patients warrant increased scrutiny. Strategies to help patients with SVCHD cope with nonmodifiable aspects of body-image during the difficult adolescent–to–young adult years may potentially enhance self-esteem and decrease psychological distress.

Protein-losing enteropathy and the Fontan operation

Protein-losing enteropathy (PLE) is a complex disorder characterized by enteric protein loss and often is associated with cardiovascular abnormalities, particularly those with elevated central venous pressure. The Fontan operation is a surgical procedure used to palliate patients with a functional single ventricle. Although the Fontan operation eliminates cyanosis and decreases the workload of the functionally single ventricle, it also elevates central venous pressure. This can result in hepatic and enteric congestion as well as PLE. Despite the universal elevation in central venous pressure, only a fraction of patients who have had a Fontan operation develop PLE. However, PLE is associated with significant morbidity and mortality. Presenting signs and symptoms of PLE include abdominal bloating, diarrhea, edema, pleural effusions, ascites, and failure to thrive. In this review, the authors discuss the diagnosis and prevalence of PLE after the Fontan operation and review currently available therapeutic strategies.

The precarious state of the liver after a Fontan operation: summary of a multidisciplinary symposium

As the cohort of survivors with the single-ventricle type of congenital heart disease grows, it becomes increasingly evident that the state of chronically elevated venous pressure and decreased cardiac output inherent in the Fontan circulation provides the substrate for a progressive decline in functional status. One organ at great risk is the liver. Wedged between two capillary beds, with the pulmonary venous bed downstream, which typically has no pulsatile energy added in the absence of a functional right ventricle, and the splanchnic bed upstream, which may have compromised inflow due to inherent cardiac output restriction characteristic of the Fontan circulation, the liver exists in a precarious state. This review summarizes a consensus view achieved at a multidisciplinary symposium held at The Children's Hospital of Philadelphia in June 2011. The discussion includes current knowledge concerning the hemodynamic foundations of liver problems, the diagnostic tools available, the unique histopathology of the liver after the Fontan operation, and proposed mechanisms for hepatic fibrosis at the cellular level. At the completion of the symposium, a consensus recommendation was made by the authors' group to pursue a new prospective protocol for clinical evaluation of the liver for all patients in our practice 10 years after the Fontan operation.

Factors affecting growth in infants with single ventricle physiology: a report from the Pediatric Heart Network Infant Single Ventricle Trial

OBJECTIVES

To describe growth patterns in infants with single ventricle physiology and determine factors influencing growth.

STUDY DESIGN

Data from 230 subjects enrolled in the Pediatric Heart Network Infant Single Ventricle Enalapril Trial were used to assess factors influencing change in weight-for-age z-score (z) from study enrollment (0.7 ± 0.4 months) to pre-superior cavopulmonary connection (SCPC; 5.1 ± 1.8 months, period 1) and pre-SCPC to final study visit (14.1 ± 0.9 months, period 2). Predictor variables included patient characteristics, feeding regimen, clinical center, and medical factors during neonatal (period 1) and SCPC hospitalizations (period 2). Univariate regression analysis was performed, followed by backward stepwise regression and bootstrapping reliability to inform a final multivariable model.

RESULTS

Weights were available for 197 of 230 subjects for period 1 and 173 of 197 subjects for period 2. For period 1, greater gestational age, younger age at study enrollment, tube feeding at neonatal hospitalization discharge, and clinical center were associated with a greater negative z (poorer growth) in multivariable modeling (adjusted R(2) = 0.39, P < .001). For period 2, younger age at SCPC and greater daily caloric intake were associated with greater positive z (better growth; R(2) = 0.10, P = .002).

CONCLUSIONS

Aggressive nutritional support and earlier SCPC are modifiable factors associated with a favorable change in weight-for-age z-score.

Renin-angiotensin-aldosterone genotype influences ventricular remodeling in infants with single ventricle

BACKGROUND

We investigated the effect of polymorphisms in the renin-angiotensin-aldosterone system (RAAS) genes on ventricular remodeling, growth, renal function, and response to enalapril in infants with single ventricle.

METHODS AND RESULTS

Single ventricle infants enrolled in a randomized trial of enalapril were genotyped for polymorphisms in 5 genes: angiotensinogen, angiotensin-converting enzyme, angiotensin II type 1 receptor, aldosterone synthase, and chymase. Alleles associated with renin-angiotensin-aldosterone system upregulation were classified as risk alleles. Ventricular mass, volume, somatic growth, renal function using estimated glomerular filtration rate, and response to enalapril were compared between patients with ≥2 homozygous risk genotypes (high risk), and those with <2 homozygous risk genotypes (low risk) at 2 time points: before the superior cavopulmonary connection (pre-SCPC) and at age 14 months. Of 230 trial subjects, 154 were genotyped: Thirty-eight were high risk, and 116 were low risk. Ventricular mass and volume were elevated in both groups pre-SCPC. Ventricular mass and volume decreased and estimated glomerular filtration rate increased after SCPC in the low-risk (P<0.05), but not the high-risk group. These responses were independent of enalapril treatment. Weight and height z-scores were lower at baseline, and height remained lower in the high-risk group at 14 months, especially in those receiving enalapril (P<0.05).

CONCLUSIONS

Renin-angiotensin-aldosterone system-upregulation genotypes were associated with failure of reverse remodeling after SCPC surgery, less improvement in renal function, and impaired somatic growth, the latter especially in patients receiving enalapril. Renin-angiotensin-aldosterone system genotype may identify a high-risk subgroup of single ventricle patients who fail to fully benefit from volume-unloading surgery. Follow-up is warranted to assess long-term impact.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique identifier: NCT00113087.

Weight change in infants with a functionally univentricular heart: from surgical intervention to hospital discharge

OBJECTIVE

The purpose of this study was to assess the pattern of weight change from surgical intervention to home discharge and to determine predictors of poor growth in this population of infants with congenital cardiac disease.

METHODS

Neonates with functionally univentricular physiology enrolled in a prospective cohort study examining growth between March, 2003 and May, 2007 were included. Weights were collected at birth, before surgical intervention, and at hospital discharge. In addition, retrospective echocardiographic data and data about post-operative complications were reviewed. Primary outcome variables were weight-for-age z-score at discharge and change in weight-for-age z-score between surgery and discharge.

RESULTS

A total of 61 infants met the inclusion criteria. The mean change in weight-for-age z-score between surgery and hospital discharge was minus 1.5 plus or minus 0.8. Bivariate analysis revealed a significant difference in weight-for-age z-score between infants who were discharged on oral feeds, minus 1.1 plus or minus 0.8 compared to infants with feeding device support minus 1.7 plus or minus 0.7, p-value equal to 0.01. Lower weight-for-age z-score at birth, presence of moderate or greater atrioventricular valve regurgitation, post-operative ventilation time, and placement of an additional central venous line were associated with 60% of the variance in weight-for-age z-score change.

CONCLUSION

Neonates undergoing staged surgical repair for univentricular physiology are at significant risk for growth failure between surgery and hospital discharge. Haemodynamically significant atrioventricular valve regurgitation and a complex post-operative course were risk factors for poor post-operative weight gain. Feeding device support appears to be insufficient to ensure adequate weight gain during post-operative hospitalisation.

Low weight-for-age z-score and infection risk after the Fontan procedure

BACKGROUND

Poor growth is common in infants with a single ventricle. Lower weight-for-age z-score (WAZ) is associated with worse short-term outcome after bidirectional Glenn procedure. We sought to assess growth status at the time of the Fontan procedure and the effect of poor growth status on surgical outcomes.

METHODS

This retrospective case series examined children who underwent Fontan at our institution between January 2003 and December 2008. Weight and height were obtained at the time of admission for Fontan. Data from preoperative echocardiogram and cardiac catheterization were abstracted to document cardiac function and hemodynamic measurements. Outcome variables included ventilator time, chest tube duration, postoperative infections (bacteremia, mediastinitis, urinary tract infection, gastroenteritis, or culture-positive pneumonia), and length of hospital stay.

RESULTS

Fifty-five patients were included for analysis. The median age at Fontan was 46 months (range, 18 to 72); median WAZ was -1.0 (-3.8 to +2.0), and height for age z-score was -1.1 (-3.7 to +1.5). The WAZ was less than -2.0 in 19% of patients. Multivariable modeling revealed that patients with a WAZ less than -2.0 (p=0.006) had a greater incidence of serious postoperative infections. The only factor predicting longer length of hospital stay was presence of a serious postoperative infection (p<0.0001). Ventilator time was predicted only by length of cardiopulmonary bypass (p=0.01). No factors were associated with longer chest tube duration.

CONCLUSIONS

Growth failure in children with a single ventricle persists through presentation for Fontan. A WAZ less than -2.0 at Fontan is associated with a higher rate of serious postoperative infections, which are associated with longer length of hospital stay.

The effect of corrective surgery on serum IGF-1, IGFBP-3 levels and growth in children with congenital heart disease

The aim of this study is to evaluate growth and insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) levels in infants with congenital heart disease (CHD) pre- and postoperatively over a period of a year. Anthropometric values and serum levels of IGF-1 and IGFBP-3 of 40 infants with CHD (20 cyanotic and 20 acyanotic) were compared with 32 healthy controls. Acyanotic infants and infants with pulmonary hypertension (PH) presented significantly more growth failure. Preoperatively, serum IGF-1 and IGFBP-3 levels were lower in the acyanotic group than the cyanotic and the control groups (p = 0.22; p < 0.01). The upward trend in IGF-1 and IGFBP-3 levels in this year-long study demonstrated that the values in the third month and the first year were higher than the preoperative values (p < 0.05). The parallel increase of weight gain and IGF-1, IGFBP-3 levels were the best evidence that these parameters are good nutritional indicators. Timing the corrective surgery before chronic malnutrition or PH develops is an important issue to maintain a normal growth for children with CHD.

Anthropometric measures after Fontan procedure: implications for suboptimal functional outcome

BACKGROUND

Abnormal height and adiposity are observed after the Fontan operation. These abnormalities may be associated with worse functional outcome.

METHODS

We analyzed data from the National Heart, Lung, and Blood Institute Pediatric Heart Network cross-sectional study of Fontan patients. Groups were defined by height (z-score<-1.5 or≥-1.5) and body mass index (body mass index [BMI] z-score<-1.5 or -1.5 to 1.5 or≥1.5). Associations of anthropometric measures with measurements from clinical testing (exercise, echocardiography, magnetic resonance imaging) were determined adjusting for demographics, anatomy, and pre-Fontan status. Relationships between anthropometric measures and functional health status (FHS) were assessed using the Child Health Questionnaire.

RESULTS

Mean age of the cohort (n=544) was 11.9±3.4 years. Lower height-z patients (n=124, 23%) were more likely to have pre-Fontan atrioventricular valve regurgitation (P=.029), as well as orthopedic and developmental problems (both P<.001). Lower height-z patients also had lower physical and psychosocial FHS summary scores (both P<.01). Higher BMI-z patients (n=45, 8%) and lower BMI-z patients (n=53, 10%) did not have worse FHS compared to midrange BMI-z patients (n=446, 82%). However, higher BMI-z patients had higher ventricular mass-to-volume ratio (P=.03) and lower % predicted maximum work (P=.004) compared to midrange and lower BMI-z patients.

CONCLUSIONS

Abnormal anthropometry is common in Fontan patients. Shorter stature is associated with poorer FHS and non-cardiac problems. Increased adiposity is associated with more ventricular hypertrophy and poorer exercise performance, which may have significant long-term implications in this at-risk population.

Insights After 40 Years of the Fontan Operation

Fontan’s visionary operation and its modifications over the ensuing decades have re-established nonturbulent flow and substantially reduced cyanosis for patients with severe hypoplasia of one ventricle. However, a long list of largely unexpected sequelae has emerged over the last 40 years. Although it is not difficult to understand how care providers could become discouraged, a number of myths have arisen, which we will attempt to dispel with real-world counterexamples as well as with lessons learned from other disciplines: evolutionary, developmental, and computational biology. We argue that distinctive biochemical abnormalities pointing to dysfunction in multiple organs, including the largest organ system in the body, the endothelium, occur long before grossly observable changes in cardiac imaging can be recognized. With a rational redesign of both our surveillance scheme and our wellness strategies, we hope that Fontan survivors and their families, as well as physicians, nurses, and therapists, will see why Fontan’s principle remains just as vibrant today as it was in 1971.

Enalapril in infants with single ventricle: results of a multicenter randomized trial

BACKGROUND

Angiotensin-converting enzyme inhibitor therapy improves clinical outcome and ventricular function in adults with heart failure. Infants with single-ventricle physiology have poor growth and are at risk for abnormalities in ventricular systolic and diastolic function. The ability of angiotensin-converting enzyme inhibitor therapy to preserve ventricular function and improve somatic growth and outcomes in these infants is unknown.

METHODS AND RESULTS

The Pediatric Heart Network conducted a double-blind trial involving 230 infants with single-ventricle physiology randomized to receive enalapril (target dose 0.4 mg . kg(-1) . d(-1)) or placebo who were followed up until 14 months of age. The primary end point was weight-for-age z score at 14 months. The primary analysis was intention to treat. A total of 185 infants completed the study. There were 24 and 21 withdrawals or deaths in the enalapril and placebo groups, respectively (P=0.74). Weight-for-age z score was not different between the enalapril and placebo groups (mean+/-SE -0.62+/-0.13 versus -0.42+/-0.13, P=0.28). There were no significant group differences in height-for-age z score, Ross heart failure class, brain natriuretic peptide concentration, Bayley scores of infant development, or ventricular ejection fraction. The incidence of death or transplantation was 13% and did not differ between groups. Serious adverse events occurred in 88 patients in the enalapril group and 87 in the placebo group.

CONCLUSIONS

Administration of enalapril to infants with single-ventricle physiology in the first year of life did not improve somatic growth, ventricular function, or heart failure severity. The results of this randomized trial do not support the routine use of enalapril in this population.

Genetic factors are important determinants of impaired growth after infant cardiac surgery

OBJECTIVES

We sought to estimate the prevalence and identify the predictors of impaired growth after infant cardiac surgery.

METHODS

We performed a secondary analysis of a prospective study of the role of apolipoprotein E gene polymorphisms on neurodevelopment in young children after infant cardiac surgery. Prevalence estimates for growth velocity were derived by using anthropometric measures (weight and head circumference) obtained at birth and at 4 years of age. Genetic evaluation was also performed. Growth measure z scores were calculated by using World Health Organization Child Growth Standards. Growth velocity was evaluated by using 2 different techniques: first by clustering the children into one of 3 growth velocity subgroups based on z scores (impaired growth, difference < -0.5 standard deviation; stable growth, difference of -0.5 to 0.5 standard deviation; and improving growth, difference > 0.5 SD) and second by using continuous difference scores. Statistical analyses were conducted with a combination of proportional odds models for the ordered categories and simple linear regression for the continuous outcomes.

RESULTS

Three hundred nineteen full-term subjects had complete anthropometric measures for weight and head circumference at birth and 4 years. The cohort was 56% male. Genetic examinations were available for 97% (309/319) of the cohort (normal, 74%; definite or suspected genetic abnormality, 26%). Frequency counts for weight categories were as follows: impaired growth, 37%; stable growth, 31%; and improving growth, 32%. Frequency counts for head circumference categories were as follows: impaired growth, 39%; stable growth, 28%; and improving growth, 33%. The presence of a definite or suspected genetic syndrome (P = .04) was found to be a predictor of impaired growth for weight but not for head circumference. When growth z scores were used as continuous outcomes, the apolipoprotein E epsilon2 allele was found to be predictive of lower z scores for both weight (P = .02) and head circumference (P = .03).

CONCLUSIONS

Impaired growth for both weight and head circumference is common (both >30%) in this cohort of children after infant cardiac surgery. Both the apolipoprotein E epsilon2 allele and the presence of a definite or suspected genetic syndrome were associated with impaired weight growth velocity. The apolipoprotein E epsilon2 allele was also associated with impaired growth velocity for head circumference. Persistent poor growth might have long-term implications for the health and development of children with congenital heart defects.