Evaluation of Physical Fitness in Children With Congenital Heart Diseases Versus Healthy Population

Abstract

We aimed to evaluate and compare the physical fitness of children with different severity of the cardiac defect with their healthy peers. We included 182 children after cooperation for congenital heart disease (CHD) and 129 healthy children as controls, 6-18 years old, who performed a complete cardiopulmonary exercise test (CPET) in a cross-sectional observational study. The CHD patients were further subdivided into three subgroups according to diagnostic characteristics and surgical methods: simple CHD group (SCHD), complex CHD group (CCHD)and total cavopulmonary connection group (TCPC). Physical fitness was compared between groups using generalized linear model and multiple linear regression analysis. In comparison with age and gender adjusted healthy controls, children in SCHD, CCHD, and TCPC subgroups had accordingly graded down values of peak oxygen consumption (VO_2max: 44.86 ± 5.41 vs. 39.91 ± 5.59 vs. 36.95 ± 5.92 vs. 32.04 ± 5.38 mL/kg/min, P < 0.05) and %predicted VO_2max (1.01 ± 0.14 vs. 0.91 ± 0.13 vs. 0.83 ± 0.15 vs. 0.72 ± 0.13, P < 0.05) for each group. The proportion of %predicted VO_2max above 80% in the CHD and the control group were 60.4% and 96.1% (P < 0.001). The VO_2max decreased by 0.98 mL/kg/min per year in CHD children, and the corresponding %predicted reference diminished by 2.0%. Children with TCPC had the highest mean decrease of VO_2max and %predicted VO_2max per year of age (1.23 mL/kg/min, corresponding 3.0%). Although the mean overall physical fitness of children with simple and complex defect after biventricular correction were significantly different from healthy population, they were close to normal (>80%predicted VO_2max). However, TCPC group had much lower exercise capacity.

Keywords: Cardiopulmonary exercise test; Congenital heart disease; Ventilatory anaerobic threshold; children.