Factors associated with low physical activity levels following pediatric cardiac transplantation

Background: Objectively measured MVPA levels following pediatric cardiac transplantation are unknown despite physical health implications. We sought to determine factors associated with MVPA in a pediatric cohort who had undergone cardiac transplantation. Methods: Study assessments included maximal exercise testing (VO₂max), accelerometry, and physical activity (HAES) and functional health status (CHQ-PF50) questionnaires. Results: Participants (n = 20, 60% male, age: 11.8 ± 3.0 yr old) had a VO₂max of 28.5 ± 6.8 mL/kg/min (%-predicted: 65 ± 14%) and maximal heart rate of 154 ± 16 beats/min (%-predicted: 73 ± 7.5%). Participants performed a median of 7.6 min/day (Q1 4.0 min/day, Q3 11.0 min/day) of MVPA. Each additional year of age at transplantation was associated with a decrease of 1.9 [1.0] min/day of MVPA (p = 0.07). Predicted VO₂max, maximal power output, male sex, and age at study enrollment were not associated with an increase in MVPA. Parents' perception of their child's functional health status (CHQ-PF50) was lower on general health (p < 0.01) and family activity (p < 0.01) domains relative to a population-based cohort of parents reporting on healthy children. Conclusion: Pediatric cardiac transplantation recipients may be indicated to participate in cardiac rehabilitation to optimize physical activity levels.