There is a growing body of evidence that exercise is safe in Fontan populations Reference Jacobsen, Ginde and Mussatto1-Reference Sutherland, Jones and d’Udekem3 and is associated with numerous health benefits. Reference Jacobsen, Ginde and Mussatto1,Reference Hedlund, Lundell and Soderstrom4-Reference Hedlund, Ljungberg and Söderström7 Exercise training in this population has been correlated with improved exercise capacity, Reference Jacobsen, Ginde and Mussatto1,Reference Opocher, Varnier and Sanders2,Reference Hedlund, Lundell and Soderstrom4,Reference Rhodes, Curran and Camil5,Reference Rhodes, Curran and Camil8-Reference Sutherland, Jones and Westcamp Aguero11 lung function, Reference Hedlund, Ljungberg and Söderström7,Reference Laohachai, Winlaw and Selvadurai12 muscle mass, Reference Cordina, O’Meagher and Karmali9 strength, Reference Cordina, O’Meagher and Karmali9 quality of life, Reference Hedlund, Lundell and Soderstrom4,Reference Scheffers, vd and Ismailova13,Reference Dulfer, Duppen and Kuipers14 and sleep hygiene. Reference Hedlund, Villard and Lundell6 Exercise has even been shown to create pulsatile Fontan blood flow, Reference Cordina, O’Meagher and Karmali9 improve inferior caval vein venous blood return Reference Cordina, O’Meagher and Karmali9,Reference Hjortdal, Emmertsen and Stenbøg15 and increase aortic flow. Reference Cordina, O’Meagher and Karmali9 While exercise is important in single-ventricle patients with Fontan circulation, they have been found to be less active than peers Reference Siaplaouras, Niessner and Helm16,Reference McCrindle, Williams and Mital17 and have reduced exercise capacity. Reference Hedlund, Lundell and Soderstrom4,Reference Brassard, Poirier and Martin18-Reference Longmuir, Corey and Faulkner25 Compared to healthy peers, patients with Fontan physiology have decreased muscle mass, Reference Cordina, O’Meagher and Gould19,Reference Tran, D’Ambrosio and Verrall26 increased adiposity, Reference Tran, D’Ambrosio and Verrall26 and a high prevalence of obesity Reference Chung, Hong and Patterson27 that increases with age. Reference Wellnitz, Harris and Sapru28
Sports participation in childhood has been linked to increased physical activity in adulthood. Reference Perkins, Jacobs and Barber29-Reference Tammelin, Näyhä and Hills32 There is growing evidence that exercise programmes can improve exercise tolerance, Reference Jacobsen, Ginde and Mussatto1,Reference Opocher, Varnier and Sanders2,Reference Hedlund, Lundell and Soderstrom4,Reference Rhodes, Curran and Camil5,Reference Rhodes, Curran and Camil8-Reference Sutherland, Jones and Westcamp Aguero11 suggesting that inactivity is a modifiable factor mediating this process. Paediatric cardiac programmes have increased efforts to institute exercise programmes, including cardiac rehabilitation programmes and exercise prescriptions. These interventions have demonstrated success at improving exercise tolerance. Reference Jacobsen, Ginde and Mussatto1,Reference Hedlund, Lundell and Soderstrom4,Reference Rhodes, Curran and Camil5,Reference Rhodes, Curran and Camil8,Reference Sutherland, Jones and Westcamp Aguero11,Reference Minamisawa, Nakazawa and Momma33 Traditionally, these programmes have been instituted in a hospital-based environment; however, given challenges associated with travel to care centres for cardiac rehabilitation, increasing attention has been paid to home-based programmes, which have demonstrated overall good results. Reference Jacobsen, Ginde and Mussatto1,Reference Brassard, Poirier and Martin18,Reference Longmuir, Tyrrell and Corey34 Ultimately, the goal of exercise programmes and prescriptions is not only to increase exercise capacity in the short term, but to also increase daily activity as a means of maintaining exercise capacity in the long term. Unfortunately, the Fontan population has continued to have decreased activity levels Reference Siaplaouras, Niessner and Helm16,Reference McCrindle, Williams and Mital17 when compared to healthy peers. The goal of our study was to examine the relationship between sports participation, obesity, and daily activity levels in children who have undergone the Fontan procedure.
Methods
We performed a single-centre retrospective cross-sectional study of all paediatric cardiology patients at Oregon Health and Science University with a diagnosis of “Fontan procedure” in their chart and who underwent an echocardiogram or were seen in paediatric cardiology ambulatory clinic between October, 2015 and January, 2020. Patients had to have undergone the Fontan procedure, be current patients in the paediatric ambulatory clinic, have no prior history of heart transplant, and be able to ambulate independently (Fig 1). Parents were then contacted for permission to participate in the study, and were subsequently given a phone survey detailing their child’s level of daily activity and participation in competitive sports within the last 12 months. Parents were contacted through April, 2020. Native Spanish speakers were interviewed in Spanish by a native Spanish-speaking paediatric cardiologist. A maximum of three attempts was made in contacting the parent or guardian. In the phone survey, parents were questioned on their child’s physical activity in comparison to recommended physical activity guidelines for children (60 minutes of moderate to vigorous physical activity daily Reference Piercy, Troiano and Ballard35 ). In surveys, moderate to vigorous physical activity was defined as “walking briskly. Reference Piercy, Troiano and Ballard35 Parents were asked to identify if their child had participated in a competitive or organised sport within the last 12 months and athletes were defined as those who had.
Figure 1. Cohort selection.
Figure 2. Single-ventricle morphologies.
Charts from the electronic medical record were subsequently reviewed. Each study patient’s last height and weight were recorded and the BMI was calculated for age and sex-based Center for Disease Control and Prevention BMI curves. Study patients were classified as “overweight” with a BMI 84–94% and “obese” with a BMI >95% in accordance with CDC guidelines. 36 The patient’s last clinic note, echocardiogram, cardiac catheterisation, MRI, CT, ambulatory cardiac monitor, and exercise test were reviewed from the EMR.
STATA software version 16.1 for Macintosh (StataCorp LLC, College Station, TX) was used for analysis. Patient characteristics and survey results were summarised using counts, percentages, medians, and interquartile ranges (expressed as 25th and 75th percentiles). Pearson’s chi-squared testing was utilised to examine categorical variables (e.g., sex, BMI category) and t-tests were used to examine continuous variables (e.g., age, BMI percentile).
Results
The total cohort of eligible patients included 58 individuals. Of these, 40 parents participated in the telephone survey (Fig 1). The final cohort was 74% male (Table 1). The median age of study patient was 12.5 ± 3.2 years with no difference between athletes (12.2 ± 3.1 years) and non-athletes (12.7 ± 3.0 years) (p = 0.56). There was an overall equal distribution of individuals between school age groups, with 37.5% in elementary school (defined as kindergarten through 5th grade), 35% in middle school (defined at 6th grade through 8th grade), and 27.5% either in higher school (defined as 9th grade through 12th grade) or recently postgraduate. Only two individuals identified as “post graduate.” Both participated in sports in the prior year. The most common single ventricle morphology was hypoplastic left heart syndrome (Fig 2). The overall cohort had minimal significant comorbid disease (Table 2). There was no statistically significant difference between the prevalence of comorbid conditions between athletes and non-athletes or between obese and non-obese individuals (Table 2).
Table 1. Cohort characteristics
Table 2. Comorbid conditions and complications for athletes and non-athletes and obese and non-obese patients
Parents reported they worry about their child due to their heart in approximately half of the cohort, with no difference between athletes (54%) and non-athletes (52%) (p = 0.91). Parents reported they sometimes limit their child’s activity equally between the athlete (23%) and non-athletes (22%) (p = 0.95). Providers recommended some form of competitive sports restriction in 12.5% of cases (n = 5). At this time, the AHA guidelines Reference Van Hare, Ackerman and Evangelista37 recommend exercise tests performed prior to sports recommendations; however, providers at our institution typically do not follow this (only two performed in cohort, one for pre-sports participation and the other due to fatigue with exercise).
Nearly one-third (30%) of the cohort reported participation in competitive sports within the last year. The most common sport played was baseball (n = 7), which was also the most common sport parents reported their child had stopped due to recommendation by their child’s cardiologist. The most common sport parents reported their child had asked to play but were not allowed due to concern for their heart was football.
The overall prevalence of obesity in the cohort was 23% with non-athletes significantly higher (33%) than athletes (0) (p = 0.02) (Table 3). There was no significant difference between overweight individuals between athletes (8%) and non-athletes (8%) (p = 0.97) (Table 3). Per parent reporting, 55% of the cohort met daily activity requirements of 60 minutes of moderate to vigorous physical activity daily, however, this was heavily skewed by athletes (77%) who were significantly more active than non-athletes (44%) (p = 0.05).
Table 3. Characteristics of athletes versus non-athletes.
Discussion
Our study found that patients with Fontan physiology who participated in competitive sports within the last year were less obese and more active than those who did not participate in sports. We also found a high overall prevalence of obesity (22.5%), higher than previously reported findings in Fontan populations of 17% Reference Chung, Hong and Patterson27 and considerably higher than peers in the state of Oregon (12.9%). 38 The high prevalence of obesity in our study was entirely skewed by non-athletes, who had a staggeringly high prevalence of obesity (33%) compared to no cases of obesity in the athletes in this Fontan cohort (p = 0.02). This prevalence of obesity is particularly deleterious in this population as increased BMI is associated with congestive heart failure and increased mortality in adults with Fontan physiology. Reference Martinez, Byku and Novak39 Our study also found that there was no difference in the prevalence of significant comorbid cardiac conditions or complications between athletes and non-athletes (Table 2). This is consistent with prior literature demonstrating that decreased activity levels in Fontan patients are independent of exercise capacity. Reference McCrindle, Williams and Mital17
At present, there are no post-surgical interventions that have demonstrated mortality benefit to patients who have undergone a Fontan Procedure. Exercise interventions, however, have demonstrated promise in improving exercise capacity in patients with Fontan physiology. Reference Jacobsen, Ginde and Mussatto1 Despite this, Fontan patients are less active than healthy peers. Reference McCrindle, Williams and Mital17 Multiple comorbid factors have been associated with reduced exercise capacity including pulmonary abnormalities, Reference Hedlund, Ljungberg and Söderström7,Reference Callegari, Neidenbach and Milanesi40-Reference Matthews, Fredriksen and Bjørnstad42 decreased muscle mass, Reference Tran, D’Ambrosio and Verrall26 and older age at Fontan Reference Madan, Stout and Fitzpatrick43 ; however, previous studies have also demonstrated that physical activity after the Fontan procedure did not correlate with cardiac status, Reference Longmuir, Russell and Corey44 or even exercise capacity. Reference McCrindle, Williams and Mital17 Studies suggest that lack of interest in exercise and health fears form major barriers to exercise. Reference Swan and Hillis45 Efforts to increase interest in exercise are therefore of chief importance in this population.
Youth participation in organised sport is an important avenue to promote lifelong activity. Reference Perkins, Jacobs and Barber29-Reference Tammelin, Näyhä and Hills32,Reference Logan, Lloyd and Schafer-Kalkhoff46 In paediatric populations, participation in competitive and organised sports in childhood has been associated with decreased social anxiety Reference Schumacher Dimech and Seiler47 and improved social skills, Reference Howe, Lukacs and Pastor48 improved mental health, Reference Snyder, Martinez and Bay49 decreased suicidality, Reference Taliaferro, Rienzo and M.50 improved physical health, Reference Snyder, Martinez and Bay49 improved health-related quality of life, Reference Vella, Cliff and Magee51 decreased BMI, Reference Logan, Lloyd and Schafer-Kalkhoff46 and even decreased cardiovascular risk. Reference Hebert, Klakk and Møller52 In young adult Fontan populations, sports participation is associated with improved exercise performance. Reference Rato, Sousa and Cordeiro10 Our study suggests that sports participation may have a role in combating obesity and maintaining daily activity. This low-cost intervention carries significant potential, but little downside.
Our study was limited by the retrospective nature of our study design. We were also limited by being a single-centre study with a small to moderate paediatric cardiac surgical programme, which inevitably led to a small single-ventricle sample size. Our study was also limited by parental report and recall bias, which may have led to inaccurate representation of their child’s level of daily activity. Future work is needed to determine the role daily activity may play in decreasing functional decline and progressive Fontan circuit inefficiency in the long term.
In conclusion, we found sports participation in paediatric Fontan patients was associated with decreased obesity and the likelihood of meeting daily activity levels. Encouraging safe sports participation may, therefore, be an important means of combating obesity and encouraging activity in this vulnerable and more sedentary population.
Acknowledgements
The authors would like to thank Dr Ben Orwell for his help with data mining.
Financial support
This research received no specific grant from any funding agency, commercial, or not-for-profit sectors.
Conflicts of interest
None.
