Exercise Capacity in Children and Adolescents With Congenital Heart Disease: A Systematic Review and Meta-Analysis

Cardiopulmonary Exercise Testing in Children and Adolescents with Repaired Tetralogy of Fallot: Mechanisms of Exercise Intolerance and Clinical Implications

By comparison with adults, cardiopulmonary exercise testing in children with Tetralogy of Fallot is limited, and its clinical application less clarified. This study provides a comprehensive CPET profile in a child-adolescent population with repaired TOF, explores mechanisms underpinning exercise intolerance and associations with clinical outcome. Seventy-four CPETs were completed in 58 child-adolescents with rTOF (age 13.8 SD 2.4 years). CPET parameters were corrected for age, sex and body size. At follow-up (4.9 years, IQR 3.5-7.9) clinical status and re-intervention was evaluated and CPET indices predicting these outcomes determined. Cohort peak V̇O2 was within low-normal limits (% pred: 74.1% SD 15.4) with 15 patients (26%) displaying moderately severe reduction in V̇O2peak (< 65% pred). Oxygen uptake efficiency slope highly correlated with V̇O2peak (r = 0.94, p < 0.001) and was insensitive to exercise intensity. No significant change in CPET occurred in patients who underwent interval testing at 24 SD 14.5 months, although there was a variable response in V̇O2peak between individuals. Chronotropic response, lung vital capacity, heart rate-V̇O2 slope (indicator of stroke volume) predicted oxygen consumption: V̇O2peak (R2 = 50.91%, p < 0.001) and workload (R2 = 58.39%, p < 0.001). Adverse clinical status was associated with reduced workload (OR 0.97, p = 0.011). V̇E/V̇CO2 slope was steeper in those that died ((%pred:137.8 SD 60.5 vs. 108.4 SD 17.0, p < 0.019). RVOT reintervention post-CPET (24 patients, 43.8%) was associated with an increased gradient of HR-VO2 slope (OR 1.042, p = 0.004). In child-adolescents with TOF important reductions in cardiopulmonary functioning were apparent in 25% of patients. Exercise intolerance was related to reduced vital capacity, impaired chronotropic response and deficient stroke volume increment.

Discovery and functional investigation of BMP4 as a new causative gene for human congenital heart disease

OBJECTIVE

Aggregating evidence highlights the strong genetic basis underpinning congenital heart disease (CHD). Here BMP4 was chosen as a prime candidate gene causative of human CHD predominantly because BMP4 was amply expressed in the embryonic hearts and knockout of Bmp4 in mice led to embryonic demise mainly from multiple cardiovascular developmental malformations. The aim of this retrospective investigation was to discover a novel BMP4 mutation underlying human CHD and explore its functional impact.

METHODS

A sequencing examination of BMP4 was implemented in 212 index patients suffering from CHD and 236 unrelated non-CHD individuals as well as the family members available from the proband carrying a discovered BMP4 mutation. The impacts of the discovered CHD-causing mutation on the expression of NKX2-5 and TBX20 induced by BMP4 were measured by employing a dual-luciferase analysis system.

RESULTS

A new heterozygous BMP4 mutation, NM_001202.6:c.318T>G;p.(Tyr106*), was found in a female proband affected with familial CHD. Genetic research of the mutation carrier's relatives unveiled that the truncating mutation was in co-segregation with CHD in the pedigree. The nonsense mutation was absent from 236 unrelated non-CHD control persons. Quantitative biologic measurement revealed that Tyr106*-mutant BMP4 failed to induce the expression of NKX2-5 and TBX20, two genes whose expression is lost in CHD.

CONCLUSION

The current findings indicate BMP4 as a new gene predisposing to human CHD, allowing for improved prenatal genetic counseling along with personalized treatment of CHD patients.

Quality of life in Arab children with congenital heart disease

BACKGROUND AND PURPOSE

Management strategies for children with congenital health diseases (CHDs) should encompass more than just the medical aspect of the disease and consider how heart diseases affect their everyday activities and, subsequently, their quality of life (QoL). Global studies witnessed a greater emphasis on studying the QoL associated with CHD. However, there is still a great lag in such data in the Arab region. The purpose of this study was to evaluate QoL in children with CHD using an Arab sample from Jordan. The specific objectives were twofold: (1) to contrast the assessments of children's QoL reported by their parents with those reported by the children themselves, and (2) to assess the factors that influence the QoL of children with CHD.

METHODS

A total of 79 children aged 2-18 with a confirmed diagnosis of CHD were included in the study, along with their mothers. Of them, 38.0% were girls, 67.1% were diagnosed with non-cyanotic CHD, 58.2% had a severe CHD, 92.4% had undergone at least one operation, 81.0% had repaired defects, 13.9% underwent palliated procedures, and 24.1% were admitted to a neonatal intensive care unit after delivery. The Pediatric Quality of Life Inventory was used to assess QoL of children with CHD. Both children's and parents' reports of QoL were analyzed using paired-sample t-tests, ANOVAs, and multiple linear regression.

RESULTS

Older children reported significantly lower QoL scores, whereas there were no differences in parents-reported QoL scores across different children age groups. There was a divergence in perceptions of QoL between parents-reported and children-reported scores with parents reporting significantly lower scores. The children-reported QoL in this study seemed to be significantly associated with their gender, age, and the presence of learning difficulties, whereas the parent-reported QoL was only associated with the presence of learning difficulties.

CONCLUSIONS

Responses from both children and parents need to be considered to understand the similarities and differences between them and to provide further insight into the optimal way to help children with CHD effectively navigate the transition into adulthood. Future research studies of outcomes for survivors of children with CHD are needed to identify high-risk survivors for worse psychosocial functioning and assess prevention measures and treatment interventions to improve their QoL.

The Role of Cardiopulmonary Testing to Risk Stratify Tetralogy of Fallot Patients

Neonatal repair has completely changed the clinical history of patients with tetralogy of Fallot (ToF); however, these patients carry a significant risk of severe arrhythmias and sudden cardiac death in the long term. The exact mechanism for late sudden cardiac death is multifactorial and still not well defined, and the risk stratification for primary prophylaxis in these patients remains challenging. Cardiopulmonary exercise testing (CPET) is a well-established and safe method to assess cardiopulmonary function in children and adults with congenital heart disease. Several parameters obtained with CPET have been identified as potential prognostic of major adverse cardiovascular events in congenital heart disease. CPET is routinely used to assess functional capacity also in patients with ToF, and there is some evidence showing its usefulness in predicting the cardiac adverse events in patients with repaired ToF. Current guidelines recognize the importance of CPET in the evaluation and management of patients with ToF, but there is no clear consensus on which the CPET parameter or level of exercise intolerance, as measured by CPET, is truly predictive of an increased risk of arrhythmia and major adverse cardiovascular events in this population. Therefore, the aim of this narrative review is to describe the current evidence on the potential use of CPET in the risk stratification of patients with repaired ToF.

Exploring the Promise of Telemedicine Exercise Interventions in Children and Adolescents With Congenital Heart Disease

Youth with congenital heart disease (CHD) have reduced exercise capacity via various physical and psychosocial mechanisms. In addition to limited physiologic exercise capacity, these patients experience lower levels of physical activity, physical activity self-efficacy, health-related quality of life, and endothelial function. The study of exercise interventions and cardiac rehabilitation programs in pediatric CHD populations remains limited, particularly home-based interventions that incorporate real-time physiologic monitoring. Home-based interventions provide improved access and convenience to patients. This is principally important for patients from geographically disperse regions who receive their care at centralized subspecialty centres, as is the case for Canadian pediatric cardiac care. These programs, however, have traditionally not permitted the supervision of safety, technique, and adherence that are afforded by hospital/facility-based programs. As such, telemedicine is an important evolving area that combines the benefits of traditional home and facility-based cardiac rehabilitation. An additional key area lacking study surrounds the types of exercise interventions in youth with CHD. To date, interventions have often centred around moderate-intensity continuous exercise. High-intensity interval training might offer superior cardiorespiratory advantages but remains understudied in the CHD population. In this review, we highlight the existing evidence basis for exercise interventions in youth with CHD, explore the promise of incorporating telemedicine home-based solutions, and highlight key knowledge gaps. To address identified knowledge gaps, we are undertaking a 12-week randomized crossover trial of a home-based telemedicine high-intensity interval training intervention in youth with repaired moderate-severe CHD using a video game-linked cycle ergometer (known as the MedBIKE; https://spaces.facsci.ualberta.ca/ahci/projects/medical-projects/remote-rehab-bike-projects).

Physical activity in relation to motor performance, exercise capacity, sports participation, parental perceptions, and overprotection in school aged children with a critical congenital heart defect

OBJECTIVE

To depict objectively measured moderate-to-vigorous physical activity (MVPA), motor performance (MP), cardiorespiratory fitness (CRF), organized sports participation, parental perceptions of vulnerability and parenting style in children with a Critical Congenital Heart Disease (CCHD), and to explore whether these factors are associated with MVPA.

STUDY DESIGN

A prospective observational cohort study in 62 7-10 years old children with a CCHD.

RESULTS

On average, children with CCHD spent 64 min on MVPA per day (accelerometry), 61 % met the international WHO physical activity guideline. Only 12 % had >60 min of MVPA daily. Eighteen percent had a motor delay (movement-assessment-battery-for children-II) and 38 % showed a below average CRF (cardiopulmonary exercise test using the Godfrey ramp protocol). Seventy-seven percent participated in organized sports activities at least once a week. Twenty-one percent of the parents are classified as overprotective (parent protection scale) and 7.3 % consider their child as being vulnerable (child vulnerability scale). A significant positive association was found between MVPA and MP (rs = 0.359), CRF(V̇O2peak/ml/kg: rs = 0.472 and Wpeak/kg: rs = 0.396) and sports participation (rs = 0.286). Children who were perceived as vulnerable by their parents showed a significantly lower MVPA (rs = -0.302). No significant associations were found between mean MVPA and parental overprotection.

CONCLUSION

Even though the majority of school aged children with a CCHD is sufficiently active, counseling parents regarding the importance of sufficient MVPA and sports participation, especially in parents who consider their child being vulnerable, could be useful. Since motor delays can be detected at an early age, motor development could be an important target to improve exercise capacity and sports participation to prevent inactivity in children with a CCHD.

Development of a knowledge, attitude, and practice scale for cardiac rehabilitation for parents of children with heart disease

PURPOSE

We aimed to (i) develop a Cardiac Rehabilitation Knowledge, Attitude, and Practice Scale for parents of children with heart disease and (ii) test its reliability and validity.

METHODS

Based on the theory of knowledge, attitude, and practice, an item pool was constructed through literature review, and 200 parents of children with heart disease were surveyed to test the reliability and validity of the scale.

RESULTS

The finalized Knowledge, Attitude, and Practice Scale contains three parts, i.e., knowledge, attitude, and practice, with a total of 34 items. The Cronbach alpha coefficient of the total scale was 0.731, the split-half reliability was 0.730, the content validity was 0.956, and the content validity of each item was 0.917-1.

CONCLUSION

The Knowledge, Attitude, and Practice Scale of Cardiac Rehabilitation for Parents of Children with Heart Disease has good reliability and validity, and it can be used as a tool to evaluate the knowledge, attitudes, and practices of parents of children with heart disease participating in cardiac rehabilitation.

PRACTICE IMPLICATIONS

The development of the Cardiac Rehabilitation Knowledge, Attitude, and Practice Scale for parents of children with heart disease is of great significance for carrying out targeted education programs in the future to improve the compliance of children with heart disease with cardiac rehabilitation programs.

A Systematic Approach for the Interpretation of Cardiopulmonary Exercise Testing in Children with Focus on Cardiovascular Diseases

Cardiopulmonary exercise testing (CPET) is the clinical standard for children with congenital heart disease (CHD), heart failure (HF) being assessed for transplantation candidacy, and subjects with unexplained dyspnea on exertion. Heart, lung, skeletal muscle, peripheral vasculature, and cellular metabolism impairment frequently lead to circulatory, ventilatory, and gas exchange abnormalities during exercise. An integrated analysis of the multi-system response to exercise can be beneficial for differential diagnosis of exercise intolerance. The CPET combines standard graded cardiovascular stress testing with simultaneous ventilatory respired gas analysis. This review addresses the interpretation and clinical significance of CPET results with specific reference to cardiovascular diseases. The diagnostic values of commonly obtained CPET variables are discussed using an easy-to-use algorithm for physicians and trained nonphysician personnel in clinical practice.

Cardiopulmonary Fitness of Preschoolers with Congenital Heart Disease: An Observational Study

With advancements in cardiopulmonary rehabilitation over the past few decades, the survival rate of patients with congenital heart disease (CHD) has increased. However, the Cardiopulmonary fitness (CPF) of these patients is poor. Here, we aimed to investigate CPF in preschoolers with CHD (aged 4 to 6 years) using cardiopulmonary exercise testing. We retrospectively compared 102 healthy preschoolers with 80 preschoolers with CHD. The latter had lower peak oxygen consumption, oxygen consumption at anaerobic threshold and metabolic equivalent at anaerobic threshold. The same result was observed in boys with CHD, but not in girls, when sex was sub-analyzed. Considering the body composition, children with CHD had a lower fat-free mass index (FFMI) than their healthy peers. Healthy preschoolers with a normal body mass index (BMI) had higher anaerobic threshold and peak metabolic equivalent values than overweight or underweight children. This was categorized under the BMI reference of the Ministry of Health and Welfare in Taiwan. In conclusion, the CPF difference between the CHD and healthy groups was identified as early as in preschool age, and better CPF in healthy preschoolers within the normal BMI range suggests the importance of weight control in young children.