CHILDREN WITH CONGENITAL HEART DISEASE EXHIBIT LOWER PHYSICAL ACTIVITY LEVELS AND LOSS OF SEASONAL PATTERNS DURING THE COVID-19 PANDEMIC

Congenital heart disease (CHD) occurs in about 1% of live births. Most patients with CHD now survive to adulthood, but they are at increased risk of secondary cardiovascular outcomes. This increased risk can be mitigated through modifiable behaviours, including physical activity. Public health measures in effect from March 2020 onward to reduce the spread of COVID-19 had widespread impacts on daily behaviours. In this study, we aimed to prospectively quantify changes in physical activity levels among children with CHD during the COVID-19 pandemic in 2020.

We measured physical activity continuously using step-counts from Fitbit trackers in a sample of children with CHD (9-16 years old at enrolment; diagnosed with coarctation of the aorta, tetralogy of Fallot, transposition of the great arteries, or Fontan circulation) participating in an ongoing prospective cohort study. In 2019 and 2020 respectively, 114 (54 % male, 12.7±2.5 years) and 93 (48% male, 13.1±2.5 years) participants had valid data. Mean daily step-counts were lower in 2020 than in 2019 (8,581±5,598 vs. 9,859±5,420, respectively, p < 0.001). The mean daily step-count was below 12,000 (an estimated equivalent of 60 minutes of moderate-to-vigorous physical activity per day) throughout 2019 and 2020. Step-count peaks (late spring and fall) and troughs (winter and summer holidays) observed in 2019 were absent in 2020. During the initial phase of the COVID-19 pandemic (spring 2020) there was a downward trend and trough in step-counts. Weekly comparison of mean daily step-counts between 2019 and 2020 demonstrated a significant decrease in 18/52 weeks (35% of the year, p < 0.05). These significant reductions corresponded to lost seasonality: all occurred in the spring (April-June) and fall (September-November), in place of anticipated peaks. In spring 2020, 68% of participants attended school virtually, while in the fall that had decreased to 9%.

There was a significant decrease in overall physical activity in children with CHD during 2020. This decrease was temporally linked to COVID-19 related public health measures. We found a loss of seasonal physical activity variations in 2020, even when the majority of participants had returned to in-person schooling. This year-long reduced physical activity is of significant concern for children with CHD. Physical activity reduces cardiovascular risk, has broad health impacts, and behavioural patterns that track into adulthood. Therefore as COVID-19 related measures continue, it is crucial to support and promote physical activity in this vulnerable population to mitigate long-term health impacts.