The prevalence of abnormal spirometry in children with CHD

BACKGROUND

The burden of pulmonary disease in children with CHD remains under-recognised. Studies have examined children with single ventricle and two ventricle heart disease and documented a decreased forced vital capacity. Our study sought to further explore the pulmonary function of children with CHD.

METHODS

A retrospective review was performed of spirometry in CHD patients over a 3-year period. Spirometry data were corrected for size, age, and gender and analysed using z-scores.

RESULTS

The spirometry of 260 patients was analysed. About 31% had single ventricle (n = 80, 13.6 years (interquartile range 11.5-16.8)) and 69% had two ventricle circulation (n = 180, 14.4 years (interquartile range 12.0-17.3)). Single ventricle patients were found to have a lower median forced vital capacity z-score compared to two ventricle patients (p = 0.0133). The prevalence of an abnormal forced vital capacity was 41% in single ventricle patients and 29% in two ventricle patients. Two ventricle patients with tetralogy of Fallot and truncus arteriosus had similar low forced vital capacity comparable to single ventricle patients. The number of cardiac surgeries predicted an abnormal forced vital capacity in two ventricle patients except tetralogy of Fallot patients.

CONCLUSION

Pulmonary morbidity in patients with CHD is common with a decreased forced vital capacity noted in single ventricle and two ventricle patients. Forced vital capacity is lower in patients with single ventricle circulation; however, two ventricle patients with tetralogy of Fallot or truncus arteriosus have similar lung function in comparison to the single ventricle group. The number of surgical interventions was predictive of forced vital capacity z-score in some but not all two ventricle patients and not predictive in single ventricle patients suggesting a multifactorial to pulmonary disease in children with CHD.

Physical Activity Promotion Among Individuals With Tetralogy of Fallot

In the general population, the most cited barriers to physical activity (PA) are time, energy, and motivation. Consequently, despite the significant contribution of PA to health and well-being, many individuals are insufficiently active. Physical inactivity and sedentary lifestyles increase the risk of acquired cardiometabolic disease, a risk that may complicate and is compounded by the anatomic and physiologic features inherent in the patient with repaired tetralogy of Fallot (ToF). Individuals with ToF commonly present with reduced exercise capacity and PA levels. In light of historically PA restrictive management of their heart disease, known reductions in exercise capacity among individuals with ToF are combined with psychosocial barriers to their participation, potentially establishing a cycle of further detraining, inactivity, and disease progression/health decline. To this end, children and young adults with ToF are known to have reduced self-efficacy towards PA, defined as their confidence in their ability to participate. In this review, we apply self-efficacy as an overarching mediator of PA participation and explore trends and determinants of PA participation among individuals with ToF and its subsequent impact on exercise capacity, disease risk, and health-related quality of life. We outline the rationale and strategies aimed at improving PA in children and adults with ToF and highlight current knowledge gaps and future directions in the promotion of PA in the population with ToF.

Abnormalities in pulmonary function and volumes in patients with CHD: a systematic review

BACKGROUND

Lung function and cardiac function are naturally correlated by sharing the thoracic cage and handling the whole cardiac output sequentially. However, lung function studies are rare in patients with CHD, although results worthy of investigation could be expected. This review summarises existing studies with the lung function parameters (spirometry and body plethysmography) in CHD patients during the last decade.

METHODS

A systematic review was performed in the relevant database (PubMed, Cochrane, and Scopus) in studies including paediatric and adult patients with CHD where lung parameters (spirometry, body plethysmography) were investigated from January 2010 to December 2020. Two independent reviewers evaluated the studies according to the Study Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies of the National Heart, Lung, and Blood Institute.

RESULTS

Eight studies investigated patients with Fontan palliation including 704 patients (306 female). Four studies included patients after repaired tetralogy of Fallot examining 219 patients (103 female), with one study using double. Further six studies included 3208 (1324 female) children and adults with various CHDs. Overall, four studies were categorised as "good", ten as "fair", and four as "poor". While the measurements were consistently standardised, references to calculate %predicted differed substantially across all studies. All evaluated studies showed reduced forced vital capacity in the majority of CHD patients.

CONCLUSIONS

Many CHD patients have a reduced forced vital capacity independent of their underlying defect. Spirometry should not only follow a standardised measure according to ATS (update 2019) but also stick to the 2012 GLI reference values.

Reduced Forced Vital Capacity and the Number of Chest Wall Surgeries are Associated with Decreased Exercise Capacity in Children with Congenital Heart Disease

Low forced vital capacity (FVC) is associated with decreased exercise capacity in CHD. Multiple prior cardiac surgeries have been associated with low FVC. We seek to understand the relationship between low FVC, number of cardiac surgeries and cardiopulmonary response leading to decreased exercise capacity. Retrospective chart review of demographics, surgical history and exercise testing including spirometry was performed in patients with CHD. Single ventricle patients were excluded. Low FVC was defined as a Z-score below the lower limit of normal. Exercise parameters were expressed as a percent of predicted. There were 93 patients with 2 ventricle CHD identified over 34 months with cardiopulmonary exercise testing. The FVC Z-score directly correlated with peak V̇O₂% (R² = 0.07, p < 0.05), and the O₂ pulse% (R² = 0.25, p < 0.0001). The VE/VCO₂ was inversely related to the FVC Z-score (R² = 0.11, p < 0.01). Patients with minimum three prior surgeries had decreased peak VO₂% (63.7 vs. 72.8, p < 0.05), decreased peak O₂ pulse% (80.8 vs. 97.9, p < 0.01) and a lower mean FVC Z-score (- 1.9 vs - 0.38, p < 0.01). The FVC Z-score and number of surgeries both predicted peak V̇O₂% in multivariate analysis. Our study demonstrated that low FVC and three or more prior cardiac surgeries were associated with lower exercise capacity and lower stroke volume response. More cardiac surgeries were also associated with low FVC. However, both low FVC and the number of surgeries were independent predictors of exercise capacity.

Does Restrictive Lung Function Affect the Exercise Capacity in Patients with Repaired Tetralogy of Fallot?

Patients with repaired Tetralogy of Fallot (rTOF) have decreased exercise capacity (XC) and restrictive lung function (RLF). Our objective was to determine the association between RLF and impaired XC in patients with rTOF. This was a single center retrospective review of patients with rTOF who underwent a cardiopulmonary treadmill exercise testing and spirometry from 2005 to 2015. Patients with a respiratory exchange ratio ≥ 1.05 and peak heart rate > 90% of predicted value were included. Forced vital capacity (FVC) and Forced expiratory volume in 1st second of forceful expiration (FEV₁) were used to classify the lung function. Exercise parameters such as peak oxygen uptake (VO₂), % of predicted VO₂ (%VO₂), Metabolic equivalents (METS), and exercise time (ET) were compared between the two groups (i) compared patients with normal lung function (normal FEV₁, FVC, and FEV₁/FVC > 80%) (ii) RLF (FVC < 80%, normal or increased FEV₁/FVC > 80%). In our cohort (n = 151, 52% male, mean age ± SD of 22.3 ± 9.1 years), patients with RLF (n = 73) compared to those with normal lung function (n = 86) had a lower peak VO₂ (30.8 ± 8.6 vs. 36.6 ± 9.8 mL/kg/min; p < 0.001) and shorter exercise time (9:23 ± 1:78 vs. 10:23 ± 1:62 min, p < 0.001). On multivariate regression analysis, RLF was independently associated with reduced XC (VO₂%) (β-coefficient - 0.182, p < 0.02) after controlling for age and gender. RLF is common in patients with rTOF and is associated with decreased XC. The contribution of RLF to reduced XC in this population should be considered prior to therapeutic decisions.

Tetralogy of Fallot in Spain: a nationwide registry-based mortality study across 36 years

BACKGROUND

Tetralogy of Fallot (TOF) is the most frequent cyanotic congenital heart defect. TOF mortality has fallen remarkably in recent years due to therapeutic advances. Accordingly, the aim of this study was to assess temporal and spatial variability in TOF-related mortality in Spain across the period 1981-2016, using data drawn from the nationwide population-based registry.

METHODS

Annual deaths due to TOF were sourced from the Spanish National Institute of Statistics database by reference to International Classification of Diseases (ICD), 9th and 10th Revision codes, namely, ICD-9 code 745.2 (period 1981-1998) and ICD-10 code Q21.3 (period 1999-2016). Age-specific and age-adjusted mortality rates were calculated, as were standardised mortality ratios (SMRs) by province, district and municipality for the period 1999-2016.

RESULTS

A total of 1035 deaths were attributed to TOF (57.78% of them were men and 42.22% were women). The age-adjusted mortality rate ranged from 0.75 per 1,000,000 inhabitants (95% confidence interval [CI]: 0-1.36) in 1981 to 0.03 per 1,000,000 (95% CI: 0.01-0.06) in 2016 for both sexes. In 2011, there was a change in the mortality trend, with a significant decrease of 49.22% per year (p < 0.001). In terms of geographical analysis, some areas with a significantly higher risk of TOF mortality were identified in the south of Spain, though no specific spatial pattern was in evidence.

CONCLUSION

The decrease in TOF mortality may be related to improvements in diagnostic and treatment techniques. More studies are needed to analyse regions with a higher mortality risk, in order to improve medical planning and resource allocation, and identify risk factors and preventive measures.

When the Heart Is Not to Blame: Managing Lung Disease in Adult Congenital Heart Disease

It is well-recognized now that adult survivors with congenital heart disease (CHD) are at risk for non-cardiac co-morbidities and complications that can impact symptoms and clinical outcomes. Lung disease, in particular, is common in this population, but likely an under-recognized and undertreated cause for long-term morbidity. Abnormal lung function contributes to exercise intolerance and is associated with a higher risk for mortality in this population. The exact mechanisms that contribute to abnormal measurements of lung function are not entirely known, and are likely multifactorial and variable depending on the underlying CHD. Nevertheless, lung disease is a potentially modifiable risk factor in this patient population, the management of which may result in improved clinical outcomes. This review summarizes our current understanding of the prevalence, impact and management of lung disease in adults with CHD.