Cardiopulmonary Exercise Test and Daily Physical Activity in Pediatric Congenital Heart Disease: an Exploratory Analysis

Sedentary lifestyle is reported to be associated with diminished exercise capacity, resulting in increased cardiovascular risk in adults with congenital heart disease (CHD). This cross-sectional study examined the association between objectively measured physical activity (PA) and exercise capacity in children and adolescents with CHD. Therefore, 107 patients (aged 13.0 ± 2.7 years, 41 girls) with various CHD performed a cardiopulmonary exercise test to quantify their peak oxygen uptake (peakV'O2). Moderate to vigorous PA (MVPA) and daily step count were assessed using Garmin vivofit jr. (Garmin, Germany) for 7 consecutive days. For association between PA and submaximal exercise capacity, Spearman correlation was performed. Patients with CHD showed almost normal values compared with the reference (79.5 ± 17.2% [31.6 to 138.1] %peakV'O2 predicted), with roughly normal ventilatory anerobic thresholds (50.6 ± 14.0% [20.3 to 97.9] % oxygen uptake at ventilatory anaerobic threshold [VATV'O2]). Step counts are below the recommendations (9,304 ± 3,792 steps/day [1,701 to 20,976]), whereas MVPA data are above the recommendations for children with ≥60 min/day (83.6 ± 34.6 min/day [10.1 to 190.9]). The Spearman rho showed significant positive correlations to VATV'O2 (r = 0.353, p <0.001) and %VATV'O2 (r = 0.307, p = 0.001), with similar results regarding MVPA (VATV'O2: r = 0.300, p = 0.002 and %VATV'O2: r = 0.270, p = 0.005). In conclusion, submaximal exercise capacity and PA correlate positively, making both assessments relevant in a clinical setting: PA in the context of cardiovascular prevention and peakV'O2 as the strongest predictor for morbidity and mortality.