Before the COVID-19 pandemic

Our data show that even before the COVID-19 pandemic, only just over half of respondents (52.8%) met national guidelines for target physical activity levels. There are several possible explanations for this. Firstly, patients with adult CHD and their parents/carers may be over-cautious about exercise due to fears of causing harm. In 2017, 66% of men and 58% of women in the United Kingdom met recommended physical activity levels according to national data collection. ^{Reference Scholes13} Contrastingly, in the adult CHD population, an international study collating data from 15 countries worldwide found 31% met physical activity guidelines. ^{Reference Larsson, Johansson and Sandberg14} It is therefore important that patients receive health promotion advice and reassurance regarding exercise from their adult CHD team.

In addition to this, healthcare professionals themselves may be uncertain about exercise recommendations given the heterogeneous population of patients encountered in the outpatient setting, with varying anatomical and physiological considerations. Although exercise is safe in the majority of patients with adult CHD, there are certain situations where caution is advised, such as those at high risk of arrhythmia. However, the risk of sudden cardiac death in adult CHD patients is rare (<0.1% per year) and only a small proportion of those deaths occur during exercise. ^{Reference Reybrouck and Mertens9,Reference Koyak, Harris and de Groot15,Reference Zomer, Vaartjes and Uiterwaal16} Mitchell et al. and the Bethesda guidelines categorise sports based on the level of exercise intensity, both dynamic and static, generally required to perform it, as well as identifying sporting disciplines which carry increased risk of bodily collision. This classification could be used to help healthcare professionals and patients understand the comparative physiological and physical stresses of different sports and thus determine most suitable categories for each individual. ^{Reference Mitchell, Blomqvist and Haskell19} Guideline recommendations specific to the adult CHD population may increase healthcare professionals’ confidence in delivering exercise recommendations.

Dua et al. explored the feasibility of providing exercise training to adult patients at all stages of adult CHD. A structured exercise programme, which involved gentle walking over a period of 10 weeks, was prescribed to patients. Quality of life and physical activity levels increased following this intervention. Moreover, patients’ treadmill test duration improved, providing evidence of the increased exercise capacity that implementing a simple physical activity intervention can achieve. ^{Reference Pelliccia, Sharma and Gati7,Reference Dua, Cooper, Fox and Graham Stuart11} Formal prescription of an exercise programme could thus be considered as a feasible option to improve physical activity levels and compliance in our patient cohort. Another useful adjunct is the provision of written guidance in the form of patient information leaflets to patients in order to develop confidence and understanding of the topic. HEART UK offers a wealth of resources detailing the benefits of exercise and provides workout videos which are openly and freely accessible to all. ¹⁷ The provision of gym tokens to patients is also an option to improve physical activity levels. It must be considered that there are expenses related to many forms of physical activity, such as membership and equipment costs. As cost was a factor reported to negatively impact activity levels, this may encourage physical activity by making gyms and sports centres more financially accessible. However, as these centres were forced to close due to the COVID-19 pandemic, such tokens would be of limited benefit while lockdown restrictions were in place.

Impact of the COVID-19 pandemic

Fear of COVID-19 was the most common reason to which reduced physical activity levels were attributed. While it is understandably difficult to allay these fears, psychological support could be offered by the responsible healthcare team. Furthermore, as our study showed some respondents undertake physical activity for its mental health benefits, exercise can be advocated as an intervention to assuage this fear and boost mental wellbeing in patients.

Closure of fitness centres was one reported reason for reduced physical activity levels during the COVID-19 pandemic. While such restrictions are in place, alternative forms of exercise should be considered in order to sustain activity levels. As clinically vulnerable populations were advised to stay inside and “shield” to protect themselves from COVID-19, options are limited, and although the advent of vaccination programmes will hopefully enable easing of lockdown restrictions in the near future, the timing of this is difficult to predict.

Some respondents reported the availability of online fitness classes to positively impact their activity levels during the pandemic. In this way, our study has identified a novel intervention that could improve compliance with exercise guidelines. Healthcare professionals should raise awareness of these online classes to their patients, in order to help them meet and maintain recommended levels of activity despite closure of fitness centres. A systematic review investigating home-based exercise programmes for patients with adult CHD found these to be a safe and feasible alternative to cardiac rehabilitation, which reaffirms the efficacy of this proposed intervention. ^{Reference Giannakoulas and Dimopoulos10,Reference Meyer, Brudy and García-Cuenllas18}

Limitations

The timing of this study should be accounted for when interpreting these results, in order that they are appropriately contextualised. Data were collected during October and November 2020, so questionnaire responses will reflect the attitudes of patients during this time, before the second lockdown was announced in the United Kingdom. In this period of summer and autumn, days are usually longer and weather more permissive to outdoor exercise. Since this study there have been two further lockdowns in the United Kingdom, over the winter months, so it is possible that exercise levels and attitudes may have changed during this time.

Our study population predominantly comprised females from a White British ethnic background, which should be accounted for when interpreting findings. Our questionnaire did not capture details of underlying congenital pathology or severity of disease, instead investigating the adult CHD population as a whole. The adult CHD population is heterogenous and it is important to consider individual pathology and physiology when making exercise recommendations.

Questionnaires are subject to social desirability bias and this is particularly important when capturing lifestyle data. It is possible that exercise levels are overstated using the questionnaire method as a result of this bias. Questionnaires are also subject to recall bias; therefore, it is impossible to say whether discussions about exercise do in fact take place at most consultations with healthcare professionals.

Finally, patients attending outpatient clinics captured with this questionnaire may have better health behaviours than those who do not attend their scheduled appointments, which is possibly a source of selection bias. Similarly, volunteer bias may be a contributing factor.

Suggestions for future research

Although exercise has been found to have benefits for both morbidity and mortality in patients with adult CHD, ESC guidelines are not specific regarding type and quantity of exercise recommended in this patient group. Instead, recommendations are extrapolated from the non- adult CHD population. More specific guideline recommendations may increase healthcare professionals’ confidence in delivering exercise recommendations. Furthermore, possible interventions to improve exercise participation should be explored with high-quality interventional studies.