Cardiopulmonary exercise testing with right-heart catheterization in patients with systemic sclerosis

To examine the role of cardiopulmonary exercise testing with right-heart catheterization (CPET/RHC) in patients with systemic sclerosis (SSc) with potentially multifactorial exertional limitation.

This was a single-center retrospective cohort study of patients with SSc referred for CPET/RHC.

A total of 19 patients with SSc [subtypes: 10 limited, 5 diffuse, 1 systemic lupus erythematosus (SLE)/SSc overlap, and 3 with no subtype specified in the medical record] underwent CPET/RHC testing from February 2003 to February 2008. Of these patients, the primary limitations to exercise were found to be ventilatory (n = 6), deconditioning/cardiovascular (n = 6), pulmonary vascular (PVL; n = 3), and exercise-induced left ventricular diastolic dysfunction (exercise-LVDD; n = 4). No prior physical examination, pulmonary function test, imaging, or echocardiographic data reliably predicted the etiology of exercise limitation determined by CPET/RHC. Vital capacity and ventilatory equivalent for CO(2) did not differ during CPET testing between PVL and exercise-LVDD, limiting the utility of CPET alone for discriminating these etiologies of dyspnea. Exercise alveolar-arterial oxygen gradient was elevated in subjects shown to have PVL [median 48 mm Hg (interquartile range 45.3, 62.0)] compared to those with exercise-LVDD [26.0 (IQR 10.6, 36.0)] and deconditioning [13.9 (IQR 4.0, 16.4); p = 0.02]. Major therapeutic changes occurred in 11/19 (58%) subjects after CPET/RHC testing.

CPET/RHC testing in subjects with SSc and potentially multifactorial dyspnea adds potentially useful diagnostic information unavailable from noninvasive testing.