Does peak exercise capacity correlate with aortic stiffness and atrial strain in children with Fontan circulation? - A case-control study

It is well known that exercise capacity is reduced in Fontan patients. However, more information is needed on exercise capacity, atrial strain, and aortic stiffness in children with Fontan circulation compared to controls and on the relationship of aortic stiffness and atrial strain with exercise capacity.

It was aimed to compare peak exercise capacity, aortic stiffness, and atrial strain with controls and to investigate the relationship between peak exercise capacity and aortic stiffness and atrial strain in children with Fontan circulation.

Demographic and clinical characteristics were recorded. Peak oxygen consumption (VO2peak) was measured using cardiopulmonary exercise test (CPET) with modified Bruce protocol on a treadmill and recorded as ml/min, ml/min/kg, %pred values according to Wasserman’s equations. Atrial strain with speckle tracking echocardiography (STE) and aortic stiffnes with pulse wave velocity (PWV) were assessed using Philips Healthcare EPIQ CVx. The dominant atrium strain was recorded for reservoir phase (εres), conduit phase (εcon), and contractile phase (εact) were recorded as %. Aortic pulse wave velocity (PWV) recorded as m/sec.

Fifteen children with Fontan circulation (median= 12 years, 6 female) and 14 controls (median=12 years, 5 female) were included. VO2peak, εres, and εcon were lower; aortic PWV were higher in patients compared to controls (p<0.05) (Table 1). VO2peak significantly associated with aortic PWV, εres, εcon, and εact in children with Fontan circulation (p>0.05) (Table 2).

Decreased exercise capacity, increased aortic stiffness, and the impaired atrial strain was found in children with Fontan circulation compared to controls in this study.Furthermore, decreased exercise capacity associated with increased aortic stiffness and impaired atrial strain. Further studies with the increased number of participants can provide new insights into determinants of exercise intolerance in children with Fontan circulation.