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Can J Cardiol. 2009 September; 25(9): e294–e300.
PMCID: PMC2780904

Language: English | French

Functional health status of adolescents after the Fontan procedure – comparison with their siblings

Abstract

BACKGROUND:

Studies have suggested that patients who have undergone the Fontan procedure experience lower functional health status and diminished exercise capacity compared with other children.

OBJECTIVES:

To compare the functional health status of Fontan patients with and without siblings, assess whether there are any differences between Fontan patients and their siblings, and determine associated factors.

METHODS:

A cross-sectional, single-centre, observational study was performed on Fontan patients 10 to 20 years of age, and their sibling closest in age, followed in a tertiary pediatric hospital. Functional health status was measured by the Child Health Questionnaire Child Form and the Pediatric Quality of Life Inventory.

RESULTS:

A total of 68 patients and 38 siblings were enrolled. Patients with siblings scored significantly lower on numerous domains of physical functional status than those without siblings. Compared with their matched siblings, Fontan patients reported significantly lower scores in all domains of the Pediatric Quality of Life Inventory and on physical (but not psychosocial) domains of the Child Health Questionnaire Child Form. Factors associated with increased patient-sibling differences included younger patient age, female sex, intracardiac lateral tunnel Fontan connection and lower ejection fraction at the time of study enrollment.

CONCLUSIONS:

Adolescents with Fontan physiology reported a lower functional health status in physical domains than their siblings, but had similar status in psychosocial domains. Having a sibling was associated with lower reported functional health status, suggesting an important effect of self-perceived physical limitations over true limitations.

Keywords: Congenital heart disease, Fontan procedure, Functional health status, Quality of life, Single ventricle

Résumé

HISTORIQUE :

Selon certaines études, les patients qui ont subi une opération de Fontan ont un état de santé fonctionnel limité et une capacité à l’exercice réduite par rapport aux autres enfants.

OBJECTIFS :

Comparer l’état de santé fonctionnel de patients ayant subi une opération de Fontan ayant ou non des frères et sœurs, évaluer s’il y a des différences entre ces patients et leur frère ou sœur et déterminer les facteurs connexes.

MÉTHODOLOGIE :

On a entrepris une étude d’observation unicentrique transversale sur des patients de dix à 20 ans ayant subi une opération de Fontan, ainsi que sur leur frère ou sœur le plus rapproché, suivis dans un hôpital pédiatriques de soins tertiaires. On a mesuré leur état de santé fonctionnel d’après le Child Health Questionnaire, version enfant et le Pediatric Quality of Life Inventory.

RÉSULTATS :

Au total, 68 patients et 38 frères et sœurs ont participé à l’étude. Les patients qui avaient des frères et sœurs ont obtenu des résultats beaucoup plus faibles dans de nombreux domaines d’état physique fonctionnel que ceux qui n’en avaient pas. Par rapport au frère ou à la sœur auxquels ils étaient jumelés, les patients ayant subi une opération de Fontan déclaraient des résultats considérablement plus faibles dans tous les domaines du Pediatric Quality of Life Inventory et dans les domaines physiques (mais non psychosociaux) du Child Health Questionnaire, version enfant. Les facteurs liés aux différences importantes entre les patients ou leur frère ou sœur étaient l’âge plus jeune, le sexe féminin, la création d’un tunnel latéral intracardiaque dans l’opération de Fontan et une fraction d’éjection plus faible au moment de l’inscription à l’étude.

CONCLUSIONS :

Les adolescents ayant une physiologie de Fontan présentaient un état de santé fonctionnel inférieur à celui de leur frère ou sœur dans les domaines physiques, mais similaire dans les domaines psychosociaux. Le fait d’avoir un frère ou une sœur s’associait à un état de santé fonctionnel déclaré plus faible, ce qui laisse supposer un effet important de la perception personnelle des limites physiques par rapport aux limites véritables.

Long-term functional outcomes have become central concerns in the management of children with severe congenital heart diseases. Patients with complex lesions precluding biventricular repair undergo staged procedures culminating in the Fontan operation, resulting in a functional, single-ventricle circulation (1,2). This cardiac physiology is known to restrict patient exercise capacity (39), and is associated with multiple morbidities and developmental problems (1013).

Studies have reported that older children and adolescents have lower functional health status and greater psychosocial difficulties after the Fontan procedure than normal population values (14,15). Conflicting studies, however, have suggested a similar level of psychosocial and physical adaptation (16,17). A recent study showed a limited correlation between Fontan patients’ actual physical capacity and their reported functional physical capacity, which suggests that self-perceived limitations may play an important role (18). The effect of self-comparison with siblings has not been previously reported. Furthermore, comparisons of Fontan patients with published normal values are of limited value because they do not account for patient socioeconomic status and familial environment, which may influence quality of life and health status. Siblings are a comparison population of interest because they live in the same environment as the patients being studied. To date, no study has directly compared the health status of a cohort of Fontan patients with matched controls instead of population-based normal values (19). We aimed to compare the functional health status of Fontan patients with and without siblings free of heart conditions to assess whether there were any differences between Fontan patients and their siblings, and to determine factors associated with greater patient-sibling differences.

METHODS

Subjects

After approval by the institutional research ethics board, eligible patients were identified from the database of the Division of Cardiology at The Hospital for Sick Children (Toronto, Ontario). Eligible subjects were English-speaking Fontan patients between 10 and 20 years of age at the time of enrollment. Patients were recruited for participation either by mail, telephone or during regular medical visits. Parents were asked to identify a healthy sibling of the patient (when available) who was closest in age (no more than five years apart) and free of any cardiac conditions or other major morbidities. Informed written consent was obtained from the parents or guardians, the patient and the participating sibling, as applicable.

Medical review

Before enrollment in the study, the medical records of all eligible patients were reviewed. Data pertaining to demographics, cardiac diagnosis, medical status and surgical care before the Fontan operation were abstracted. Specifics of the Fontan procedure and details of postoperative care and long-term follow-up were also reviewed.

Questionnaires

One parent or guardian (usually the mother) was asked to provide information on the patient’s and the sibling’s achievements in school, medical problems or disabilities, and the patient’s physical, emotional and social problems. Additionally, parents were asked to complete the Pediatric Quality of Life Inventory (PedsQL) Generic Core Scales Parent Proxy Report (20). Patients and siblings were asked to complete the age-appropriate PedsQL and Child Health Questionnaire Child Form (CHQ-CF87).

PedsQL

The PedsQL questionnaire (21,22) is composed of 23 Likert scales divided into four functional health domains assessing physical, emotional, social and school functioning. The questionnaire is age-appropriate (child version for eight to 12 years and adolescent version for 13 to 20 years of age) and the parental proxy report has been validated (20,23).

CHQ-CF87

The CHQ-CF87 (24) is composed of 87 items assessing 13 functional health domains of physical, emotional and behavioural functioning as well as the responder’s ability to perform age-specific roles (Appendix 1 ) (25,26). As with the PedsQL, the CHQ-CF87 is age-appropriate and the parental proxy report has been validated. Established population-based normal scores for some domains of the CHQ-CF87 have been calculated based on 950 healthy American school-aged children and validated in other populations (2628).

Data analysis

Data are presented as mean ± SD, medians with minimum and maximum values, and frequencies as appropriate. Simple comparisons were obtained using Student’s t tests (with Satterthwaite correction if necessary) and Fisher’s exact tests. Differences in scores between patients with and without a sibling, and between patients and their siblings were assessed using unpaired and paired t tests, respectively. Differences between patients with and without siblings were tested in multivariable models alongside the factors listed below to test for effect independence. Differences in scores between patients or siblings and population-based normal scores were assessed through z tests.

It was hypothesized that patient age, sex, underlying cardiac anatomy, type of Fontan connection, time since Fontan surgery and ejection fraction at the time of questionnaire completion would be associated with differences between patients and their siblings. A univariate linear regression model, based on maximum likelihood estimates, was created to determine the associations between patient-sibling paired differences and the aforementioned variables. Missing values for potential predictors were imputed when appropriate; however, missing test scores were not. All data analyses were performed using SAS version 9.1 (SAS Institute Inc, USA).

RESULTS

Patient population

A total of 95 Fontan patients from the hospital database were determined to be eligible for the present study. Of these, 13 patients could not be contacted and 14 declined to participate. The study was completed by 68 patients (44 [65%] girls; mean age 13±2 years), 38 of whom had siblings who agreed to participate (19 [50%] girls; mean age 15±3 years). The PedsQL was completed by 67 (99%) patients, 66 (97%) parents or guardians and 37 siblings (97%). The CHQ-CF87 was completed by 66 (97%) patients (seven of whom gave incomplete answers) and 38(100%) siblings (six of whom gave incomplete answers). A total of 66 (97%) patients and 37 (97%) siblings answered both questionnaires. Patient and sibling characteristics are summarized in Table 1, and complete medical and surgical details are shown in Appendix 2.

TABLE 1
Patient and sibling characteristics and clinical status

Patient’s recent clinical history

Parents answered questions about their child’s recent medical history (Table 1). Compared with their siblings, Fontan patients were more likely to require extra help in school (27% versus 11%, P=0.007), have physical disabilities (21% versus 0%, P=0.002) and to regularly take medication (67% versus 16%, P<0.001). As reported by their parents or guardians, 32 (48%) Fontan patients had less energy than other children, 30 (45%) had shortness of breath with mild or moderate exercise, 40 (60%) had a reduced ability to exercise in cold and hot weather, 15 (22%) experienced sweating not related to physical activity or heat, 15 (22%) had puffiness in the face, hands, abdomen or ankles, and nine (13%) had balance and coordination problems. Parents reported behavioural problems in six (9%), conduct disorders in four (6%), hyperactivity in three (5%) and learning disabilities in 17 (25%) children.

Effect of siblings

Fontan patients with siblings had significantly lower scores than patients without siblings. Patients without siblings scored higher on the CHQ-CF87 physical functioning scale (91±9 versus 82±20, P=0.02) and role functioning-physical scale (97±8 versus 87±23, P=0.02) than patients with siblings. Similar findings were observed for the PedsQL physical functioning (96±3 versus 93±7, P=0.01) and school functioning (91±7 versus 86±8, P=0.01) domains. These associations were independent in multivariable models of other factors that were hypothesized to influence the functional health status of Fontan patients (age, sex, underlying anatomy, type of Fontan connection, time since Fontan surgery and ejection fraction at the time of study). In multivariable models, patients with siblings had lower physical functioning domain scores on the CHQ-CF87 (−8±4, P=0.03) and lower role functioning-physical domain scores (−10±4, P=0.03) than those without siblings. They also had lower scores on the PedsQL physical functioning (−4±1, P=0.01) and school functioning (−5±2, P=0.04) domains.

PedsQL

Patient, sibling and parent PedsQL scores are shown in Figure 1. Fontan patients scored significantly lower than their siblings in all domains. Although the difference was statistically significant, the magnitude of the difference was somewhat marginal. Parent and patient scores were not significantly different from each other; however, parents consistently rated their child’s health status lower than the patients did themselves.

Figure 1)
A, B and C Comparisons among patient (n=66), sibling (n=38) and normal average scores on the Child Health Questionnaire Child Form (CHQ-CF87). Patient-sibling significant paired differences (n=38): global health (P<0.01), physical functioning ...

CHQ-CF87

Patients’ CHQ-CF87 scores compared with their siblings’ scores and population-based normal values (when available) are detailed in Figure 1. Fontan patients scored significantly lower than their siblings in all four domains of physical activity and functioning. However, they had similar scores in all nine domains of emotional health, social functioning and behaviour. Fontan patients reported significantly lower scores on the physical functioning domain (81±15 versus 88±21, P=0.01) than published population normal values, and significantly higher scores on the behaviour domain (81±15 versus 77±15, P=0.03). Siblings had significantly higher than normal scores for three domains of physical health (physical functioning, 97±5 versus 89±14, P<0.01; role functioning-physical, 95±15 versus 87±22, P=0.05; and general health, 78±13 versus 66±15, P<0.01) and for the role functioning-behaviour domain (98±6 versus 87±22, P<0.01). Both Fontan patients and their siblings scored significantly lower than normal values on the self-esteem scale (67±9 and 68±9, respectively versus 82±16, P<0.01). Fontan patients and their siblings had similar scores on multiple domains of emotional and psychosocial function.

Patient-specific factors associated with paired patient-sibling differences

Factors associated with greater patient-sibling differences in PedsQL domains are described in Table 2. Patient-sibling differences in emotional (P<0.0001) and social functioning domains (P<0.0001) were larger for younger patients; however, differences in school functioning (P=0.003) were larger for older patients. Compared with male patients, female patients experienced greater differences in social functioning (P=0.001) and school functioning (P<0.0001). Medical factors associated with greater differences between patients and siblings on the PedsQL physical domain were diagnoses other than double-inlet left ventricle (P<0.0001), longer time since Fontan surgery (P=0.05) and lower ejection fraction at the time of the study (P<0.0001). Differences between patients and siblings in emotional and school functioning reduced with increasing time since the Fontan surgery and higher ejection fraction at the time of the study.

TABLE 2
Univariate, patient-specific factors associated with paired patient-sibling differences in Pediatric Quality of life Inventory (PedsQL) scores

Factors influencing patient-sibling differences in CHQ-CF87 domains, in which scores were significantly lower for patients than for siblings, are detailed in Table 3. Older patient age was associated with greater deficits in general health (P<0.0001) and role functioning-physical (P<0.0001) domains compared with siblings. Female patients were found to have greater differences in global health (P=0.01) and role functioning-physical (P=0.001) domains. Greater differences in CHQ-CF87 domain scores between patients and siblings were associated with diagnoses other than double-inlet left ventricle, longer time since Fontan surgery, intracardiac lateral tunnel Fontan connection type and lower ejection fraction at the time of the study.

TABLE 3
Univariate, patient-specific factors associated with paired patient-sibling differences in Child Health Questionnaire Child Form (CHQ-CF87) scores

DISCUSSION

Summary

Patients without siblings had significantly higher scores than those with siblings on most domains of physical health, suggesting that self-comparison between patients and their siblings may affect self-perception. However, these differences seem to have a limited effect on patient-sibling differences with respect to psychosocial indicators. After the Fontan procedure (even years later), children and adolescents had a high frequency of morbidities that were associated with significantly lower physical functioning compared with their healthy siblings. Their psychosocial functioning was found to be comparable, albeit marginally lower, than that of their siblings. These findings somewhat contradict previous studies, which found that limitations in physical functioning were associated with more psychosocial difficulties (15,29). The results of the present study suggest that although physical functioning is lower following the Fontan procedure, it does not necessarily result in lower psychosocial status, as noted in other studies (14,16,17). Differences in functional status were found to be linked to the underlying diagnosis, type of Fontan connection, time since Fontan surgery and especially, ventricular function at the time of the study.

Influence of siblings on self-perception

The association between the presence or absence of a sibling and scores on physical domains of functional status, as found in our study, was not previously reported. Patients with and without siblings are similar in medical and surgical characteristics; however, patients without siblings scored better on many domains of physical functioning. As suggested by McCrindle et al (18), part of a Fontan patient’s physical restrictions may be a reflection of his or her own perception rather than true limitations. In this case, having a brother or sister who is not limited physically may alter the Fontan patient’s self-perception and create a greater impression of activity limitation, resulting in lower self-perceived functional health status.

Functional status in Fontan patients

Optimal long-term functional health status of Fontan patients is a complicated concept to define because Fontan patients encompass a wide range of underlying diagnoses and surgical management has greatly progressed over time (30,31). Although this specific group reported greater functional status than other Fontan and cardiac populations (15,32,33), they continue to face reduced exercise capacity. These patients were determined to be at high risk for many comorbidities that do affect their functional status, as demonstrated by significantly lower scores than their siblings on all measures of physical functioning. However, the fact that Fontan patients do not score significantly worse on CHQ-CF87 domains other than physical functioning, suggests a limited effect on psychosocial status.

The perception of functional status

In recent years, much attention has been given to the reliability of parent proxy assessment of child development and functional status (3436). Differences in parent proxy and child reports have been documented in the literature, showing that parents usually score their child’s functional status lower than the child themselves (37); however, greater agreement has been noted among parents of children with chronic conditions (38). The PedsQL results from our study suggest that although parents tend to marginally under-score their child’s functional status, the difference is not significant. Parents appear to be a reliable proxy in this context.

The use of population-based values has been found to be problematic. Even siblings unaffected by cardiac conditions had scores significantly different from published normal values, suggesting that matched controls from similar sociodemographic environments are more appropriate in this situation than population-based normal values. Therefore, siblings are ideal in this context because they share a nearly identical demographic and familial environment with the patient.

Factors affecting patient-sibling differences

Patients with more favourable diagnoses (double-inlet left ventricle) were found to experience fewer differences from their sibling than patients with less favourable diagnoses such as hypoplastic left heart syndrome and tricuspid atresia. This suggests that the initial medical condition has a long-lasting impact on these children, even years after the Fontan surgery. These findings are consistent with other studies that have reported an association among underlying cardiac and non-cardiac diagnoses, treatment complexity and long-term functional outcomes in Fontan patients (11,39).

Surgical management was also found to affect differences in functional status between patients and siblings. An intracardiac lateral tunnel Fontan connection is known to be associated with long-term physical outcomes that are inferior to an extracardiac conduit connection (4042). Intracardiac lateral Fontan connections and poor ventricular function were associated with greater patient-sibling differences, which suggests that suboptimal surgical outcomes are linked to lower functional health status. These variables were also associated with lower psychosocial scores and resulted in greater paired differences between patients and siblings.

Limitations

The present study must be viewed in light of some limitations. We cannot exclude a selection bias for the present population, especially because CHQ scores were higher than previously reported. Patients selected for the present study may represent the higher spectrum of functional status for Fontan patients. However, while the determinants of health status in Fontan patients cannot be generalized to the entire Fontan population, the comparison with their siblings is of high interest and has not been reported previously. Medical record review was the data source for a patient’s medical history and there are potential limitations to the reliability and completeness of these data.

The overlap between scales and the large number of variables tested in the present study make the analysis susceptible to multiple comparison bias. Therefore, we used a hypothesis-driven approach to explore relationships between medical characteristics and patient-sibling differences in health status. Study conclusions are based solely on associations seen with many similar domains.

CONCLUSIONS

Differences between patients with and without siblings suggest that, at least to some degree, differences in functional health status could be due to self-perceived limitations rather than true physical deficits. The present study is unique because it compares the functional health status of a Fontan patient population with that of their healthy siblings and does not solely rely on population-based normal data for comparison. We determined that although Fontan patients experienced lower physical function than their siblings, psychosocial domain scores were comparable, suggesting some degree of coping. Impaired ventricular function was found to be associated with lower scores and greater differences between patients and their siblings. With appropriate support and physical rehabilitation, these patients may be able to achieve functional health status comparable with that of normal healthy children.

Acknowledgments

The authors acknowledge the work of Patrick Glasgow.

APPENDIX 1

Child Health Questionnaire Child Form (CHQ-CF87) scales, interpretation of low and high scores

CHQ CF-87 domainDescription of low scoresDescription of high scores
General healthChild believes their health is poor and likely to get worseChild believes their health is excellent and will continue to be so
Physical functioningChild is very limited in performing all physical activities, including self-care, due to healthChild performs all types of physical activities, including the most vigorous, without limitations due to health
Role functioning-physicalChild is limited a little in schoolwork or activities with friends as a result of physical healthChild has no limitations in schoolwork or activities with friends as a result of physical health
Bodily painChild has extremely severe, frequent and limiting bodily painChild has no pain or limitations due to pain
General behaviourChild very often exhibits aggressive, immature or delinquent behaviourChild never exhibits aggressive, immature or delinquent behaviour
Role functioning-behaviourChild is limited a little in schoolwork or activities with friends as a result of behaviour problemsChild has no limitations in schoolwork or activities with friends as a result of behaviour problems
Role functioning-emotionalChild is limited a little in schoolwork or activities with friends as a result of emotional problemsChild has no limitations in schoolwork or activities with friends as a result of emotional problems
Mental healthChild has feelings of anxiety and depression all of the timeChild feels peaceful, happy and calm all of the time
Self-esteemChild is very dissatisfied with abilities, looks, family/peer relationships and life overallChild is very satisfied with abilities, looks, family/peer relationships and life overall
Family cohesionFamily’s ability to get along is rated “poor”Family’s ability to get along is rated “excellent”

Data from references 24 and 25

APPENDIX 2

Detailed patient characteristics

ValueNm
Specific cardiac diagnosis
  Isomerism6/68 (9)0
  Great arteries abnormality6/68 (9)0
  Dextrocardia6/68 (9)0
  Left dominant ventricle48/68 (71)0
  Atrioventricular valve regurgitation42/66 (64)2
  Pulmonary artery stenosis34/68 (50)0
  Subaortic stenosis21/67 (31)1
Surgical procedures before Fontan procedure
  Number of procedures before Fontan2±1 (0–4)1
  Pulmonary angioplasty26/67 (39)1
  Damus-Kaye-Stansel procedure8/68 (12)0
  Subaortic resection11/68 (16)0
  Pulmonary artery banding13/68 (19)0
  Blalock-Taussig shunt45/68 (66)0
  Early (<30 days of age)23/68 (34)0
  Late (>30 days of age)22/68 (32)0
  Bicavopulmonary anastamosis44/67 (65)1
  Preoperative arrhythmia16/67 (24)1
Last catheterization before Fontan procedure
  Pulmonary artery pressure, mmHg11±4 (1–18)3
  Left ventricular end-diastolic pressure, mmHg7±2 (2–12)6
  Systolic ejection fraction, %64±10 (44–84)28
  Oxygen saturation, %83±5 (70–99)0
Fontan connection type
  Atriopulmonary9/68 (13)0
  Atrioventricular2/68 (3)0
  Internal intracardiac lateral tunnel18/68 (26)0
  External intracardiac lateral tunnel28/68 (41)0
  Extracardiac conduit11/68 (16)0
  Weight at surgery, kg16.7±8.3 (10–63)0
  Use of Gor-Tex in Fontan connection41/66 (62)2
  Fenestration performed44/68 (65)0
  Size of fenestration, mm4.0±0.5 (3.0–5.0)27
  Aortic cross-clamp time, min52±19 (24–95)6
  Cardiopulmonary bypass time, min135±47 (64–323)2
  Intensive care unit stay, days6±9 (1–74)8
  Duration of hospitalization, days19±16 (8–95)2
Complications post-Fontan/follow-up
  Pleural effusion25/66 (38)2
  Pericardial effusion15/66 (23)2
  Postoperative arrhythmia24/65 (37)3
  Central nervous system deficits8/66 (12)2
  Thrombosis2/68 (3)0
Last catheterization post-Fontan procedure
  Interventional catheterization14/66 (21)2
  Pulmonary artery pressure, mmHg12±4 (6–28)25
  Left ventricular end-diastolic pressure, mmHg7±3 (1–18)36
  Pulmonary vascular resistance index, L/min/m21.5±1.1 (0.2–4.7)29
  Oxygen saturation, %91±4 (76–98)4
  Venous collaterals15/66 (23)2

Data presented as n/n (%) or mean ± SD (range). Nm Number missing

Footnotes

SUPPORT: Supported in part by the CIBC World Markets Children’s Miracle Foundation Chair in Child Health Research.

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