Reference standards and diagnosis-specific trends in cardiorespiratory fitness in paediatric patients with repaired...

Exercise capacity (VO_2peak) predicts mortality in adult patients with CHD. There is a lack of paediatric exercise capacity data based on specific CHD lesions, limiting the ability to contextualise interpretation based on expected performance during testing. The primary aim of this study was to establish VO_2peak percentiles for paediatric patients with repaired CHD undergoing treadmill-based cardiopulmonary exercise testing (CPET).

Retrospective analysis of CPET data from 2004 to 2022. CPETs were analysed for patients with CHD aged 6-18 years. Patients with repaired CHD were categorised based on their most haemodynamically significant CHD lesion. Percentiles and age-based trends were plotted for each group.

A total of 887 patients were included. CHD patients were divided into ten diagnostic subgroups. The mean percent expected VO_2peak for each of the subgroups were as follows: Atrial and ventricular septal defect (94.5 ± 25.1%), pulmonary valve repair (88.1 ± 18.4%), aortic valve repair (92.7 ± 16.4%), tricuspid and mitral valve repair (81.3 ± 20.4%), coarctation of the aorta (93.6 ± 18.8%), transposition of the great arteries (90.5 ± 19.4%), double outlet right ventricle and truncus arteriosus (80.5 ± 16.2%), tetralogy of Fallot (85.6 ± 20.9%), left ventricle dominant Fontan (74.7 ± 18.3%), and right ventricle dominant Fontan (75.7 ± 16.7%).

There is a varying degree of reduced exercise capacity in paediatric patients with repaired CHD. Univentricular hearts and tricuspid and mitral valve repair have the lowest VO_2peak. These CHD-specific percentiles may help providers risk-stratify and counsel patients with CHD.