Characteristics of exercise intolerance in different subgroups of pulmonary arterial hypertension associated with congenital heart disease

Exercise intolerance is a major manifestation of pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD). We aimed to investigate the characteristics of exercise intolerance in different subgroups of PAH-CHD.We retrospectively enrolled 171 adult patients with PAH-CHD and 30 age and sex-matched healthy subjects and performed cardiopulmonary exercise testing. Gas exchange parameters, including peak oxygen uptake (peak V̇oThe median age of patients at enrollment was 27.8 years, and 131 (76.6%) were female. Peak V̇oExercise capacity was severely reduced in patients with PAH-CHD. Among the four subgroups, patients with Eisenmenger syndrome had the worst exercise capacity and ventilatory efficiency.