Review question
This review aimed to gather evidence for the use of any physical activity intervention for people with congenital heart disease. We aimed to compare interventions including exercise training, physical activity promotion or lung training with no intervention (usual care).
Background
Congenital heart disease is the term used for a range of birth defects that affect how the heart works. People with congenital heart disease have reduced life expectancy, physical fitness and quality of life. However, due to better prenatal diagnoses, surgical procedures (often performed in the early years of life) and earlier interventions, the survival rate for those born with this disease has improved dramatically, such that most people will now live into adulthood. Exercise training and physical activity interventions are known to improve fitness, physical activity, survival and quality of life in healthy people, but it is not clear how effective these programmes are for people with long-term medical conditions.
Study characteristics
We searched for studies in September 2019 and identified 15 studies involving 924 participants. The studies used three main types of interventions, including programmes designed to increase physical activity, aerobic fitness and health-related quality of life and compared physical activity intervention and control interventions in people with congenital heart disease.
Key results
We included 15 trials with 924 participants. Half of the participants were female. Of the 15 trials, 5 used a total of 500 young people (less than 18 years of age) and 10 trials used a total of 424 adult participants. We found that physical fitness and physical activity may slightly increase but we are very uncertain about quality of life. There is currently no data to say if this small increase in fitness will result in fewer visits to the hospital. But there were no recorded deaths or serious events that were related to participation in physical activity.
Quality of evidence
Using a validated scientific approach (GRADE), the certainty in the evidence base was moderate for fitness, low for physical activity and very low for quality of life. Most outcomes were limited due to small study participant numbers and poor reporting of study details.
This review summarises the latest evidence on CRF, HRQoL and PA. Although there were only small improvements in CRF and PA, and small to no improvements in HRQoL, there were no reported serious adverse events related to the interventions. Although these data are promising, there is currently insufficient evidence to definitively determine the impact of physical activity interventions in ConHD. Further high-quality randomised controlled trials are therefore needed, utilising a longer duration of follow-up.
Congenital heart disease (ConHD) affects approximately 1% of all live births. People with ConHD are living longer due to improved medical intervention and are at risk of developing non-communicable diseases. Cardiorespiratory fitness (CRF) is reduced in people with ConHD, who deteriorate faster compared to healthy people. CRF is known to be prognostic of future mortality and morbidity: it is therefore important to assess the evidence base on physical activity interventions in this population to inform decision making.
To assess the effectiveness and safety of all types of physical activity interventions versus standard care in individuals with congenital heart disease.
We undertook a systematic search on 23 September 2019 of the following databases: CENTRAL, MEDLINE, Embase, CINAHL, AMED, BIOSIS Citation Index, Web of Science Core Collection, LILACS and DARE. We also searched ClinicalTrials.gov and we reviewed the reference lists of relevant systematic reviews.
We included randomised controlled trials (RCT) that compared any type of physical activity intervention against a 'no physical activity' (usual care) control. We included all individuals with a diagnosis of congenital heart disease, regardless of age or previous medical interventions.
Two review authors (CAW and CW) independently screened all the identified references for inclusion. We retrieved and read all full papers; and we contacted study authors if we needed any further information. The same two independent reviewers who extracted the data then processed the included papers, assessed their risk of bias using RoB 2 and assessed the certainty of the evidence using the GRADE approach. The primary outcomes were: maximal cardiorespiratory fitness (CRF) assessed by peak oxygen consumption; health-related quality of life (HRQoL) determined by a validated questionnaire; and device-worn ‘objective’ measures of physical activity.
We included 15 RCTs with 924 participants in the review. The median intervention length/follow-up length was 12 weeks (12 to 26 interquartile range (IQR)). There were five RCTs of children and adolescents (n = 500) and 10 adult RCTs (n = 424). We identified three types of intervention: physical activity promotion; exercise training; and inspiratory muscle training. We assessed the risk of bias of results for CRF as either being of some concern (n = 12) or at a high risk of bias (n = 2), due to a failure to blind intervention staff. One study did not report this outcome. Using the GRADE method, we assessed the certainty of evidence as moderate to very low across measured outcomes.
When we pooled all types of interventions (physical activity promotion, exercise training and inspiratory muscle training), compared to a 'no exercise' control CRF may slightly increase, with a mean difference (MD) of 1.89 mL.kg−1.min−1 (95% CI −0.22 to 3.99; n = 732; moderate-certainty evidence). The evidence is very uncertain about the effect of physical activity and exercise interventions on HRQoL. There was a standardised mean difference (SMD) of 0.76 (95% CI −0.13 to 1.65; n = 163; very low certainty evidence) in HRQoL. However, we could pool only three studies in a meta-analysis, due to different ways of reporting. Only one study out of eight showed a positive effect on HRQoL. There may be a small improvement in mean daily physical activity (PA) (SMD 0.38, 95% CI −0.15 to 0.92; n = 328; low-certainty evidence), which equates to approximately an additional 10 minutes of physical activity daily (95% CI −2.50 to 22.20).
Physical activity and exercise interventions likely result in an increase in submaximal cardiorespiratory fitness (assessed with VO2 mL.kg-1.min-1 at the gas exchange threshold; MD 2.05, 95% CI 0.05 to 4.05; n = 179; moderate-certainty evidence). Physical activity and exercise interventions likely increase muscular strength (measured by maximal voluntary contraction of knee extensions; MD 17.13, 95% CI 3.45 to 30.81; n = 18; moderate-certainty evidence). Eleven studies (n = 501) reported on the outcome of adverse events (73% of total studies). Of the 11 studies, six studies reported zero adverse events. Five studies reported a total of 11 adverse events; 36% of adverse events were cardiac related (n = 4); there were, however, no serious adverse events related to the interventions or reported fatalities (moderate-certainty evidence). No studies reported hospital admissions.