Utility of cardiopulmonary stress testing in assessing disease severity in children with pulmonary arterial hypertension.

This study sought to assess the safety of cardiopulmonary stress testing in 40 children with pulmonary arterial hypertension and to compare exercise responses in this patient cohort with those of a healthy control population. Patients with pulmonary hypertension had significant impairment in aerobic capacity, with a peak oxygen consumption of 20.7 +/- 6.9 versus 35.5 +/- 7.4 ml/kg/min in healthy controls (p <0.0001). Peak oxygen consumption was strongly correlated with invasive measures of disease severity, including pulmonary vascular resistance index (r = -0.6, p = 0.006). Exercise testing can be performed safely in this group of patients and can yield valuable clinical information.