Arterial Stiffness and Its Relationship to Cardiorespiratory Fitness in Children and Young Adults with a Fontan Circulation

Abstract

There are no previous studies on arterial stiffness and its associations with cardiorespiratory fitness in young Fontan patients. Therefore, we examined the arterial stiffness and its relationship to cardiorespiratory fitness in children and young adults with a Fontan circulation. Altogether, 17 Fontan patients and 26 healthy controls (16 females and 27 males aged 8-40 years) participated in this cross-sectional study. The cardiorespiratory fitness was assessed by cardiopulmonary exercise testing on a cycle ergometer and was defined as the standard deviation scores (SDS) of peak oxygen uptake per body mass (VO_2peak/kg) based on the national reference values and assessed with cardiopulmonary exercise testing on a cycle ergometer. Aortic pulse wave velocity (PWV_ao) as a measure of arterial stiffness and aortic Augmentation Index (AIX) as a measure of peripheral arterial tone, were assessed by non-invasive oscillometric device from upper arm. Body adiposity was determined by body mass index SDS and the sport participation by interview. Data were analyzed using linear regression analyses and Pearson's correlations, adjusted for age and sex. Fontan patients had a lower VO_2peak/kg-SDS (- 2.69 vs 0.078), higher PWV_ao-SDS (1.13 vs - 0.24) and higher AIX (19.26% vs 8.49%) in comparison with healthy controls. PWV_ao and AIX were negatively associated with VO_2peak/kg (standard regression coefficient (β) - 0.525, 95% confidence interval (CI) - 0.722 to - 0.227, p < 0.01 and β - 0.371, 95% CI - 0.672 to - 0.080, p = 0.014). Young Fontan patients have the arterial stiffness of healthy people who are twice as old. Thereby, children and young adults with a Fontan circulation have a lower cardiorespiratory fitness and less sport participation. Arterial stiffness is inversely associated with cardiorespiratory fitness and exercise training might be an intervention to improve vascular health in this population.

Keywords: Arterial stiffness; Augmentation Index; Cardiorespiratory fitness; Fontan circulation; Pulse wave velocity; Univentricular heart; Youth.