Prognostic value of cardiopulmonary exercise testing in patients with systemic sclerosis

• Published in: BMC pulmonary medicine Vol. 19; no. 1; pp. 230 - 12
• Main Authors: Ewert, Ralf, Ittermann, Till, Habedank, Dirk, Held, Matthias, Lange, Tobias J., Halank, Michael, Winkler, Jörg, Gläser, Sven, Olschewski, Horst, Kovacs, Gabor
• Format: Journal Article
• Language: English
• Published: London BioMed Central 29.11.2019; BioMed Central Ltd; BMC
• Subjects: Age; Aged; Analysis; Body mass index; Body weight; Carbon dioxide; Cardiology; Cardiopulmonary exercise; Care and treatment; Comorbidity; Critical Care Medicine; Echocardiography; Exercise; Exercise Test; Female; Gender; Health aspects; Heart; Humans; Hypertension; Infectious; Intensive; Internal Medicine; Lung diseases; Lung volume measurement; Male; Medical prognosis; Medical research; Medicine; Medicine & Public Health; Middle Aged; Mortality; Pneumology/Respiratory System; Prognosis; Pulmonary arteries; Pulmonary artery; Pulmonary function; Pulmonary hypertension; Pulmonology; Rare and Idiopathic Pulmonary Diseases; Regression analysis; Research Article; Respiratory tract diseases; Retrospective Studies; Scleroderma; Scleroderma (Disease); Scleroderma, Systemic - diagnosis; Studies; Systemic sclerosis; Walking; Prognosis; Cardiopulmonary exercise; Pulmonary function; Systemic sclerosis; Pulmonary hypertension
• ISSN: 1471-2466; 1471-2466
• DOI: 10.1186/s12890-019-1003-7

Background Systemic sclerosis (SSc) is a severe rheumatic disease of the interstitial tissue, in which heart and lung involvement can lead to disease-specific mortality. Our study tests the hypothesis that in addition to established prognostic factors, cardiopulmonary exercise testing (CPET) parameters, particularly peak oxygen uptake (peakVO 2 ) and ventilation/carbon dioxide (VE/VCO 2 )-slope, can predict survival in patients with SSc. Subjects and methods We retrospectively assessed 210 patients (80.9% female) in 6 centres over 10 years with pulmonary testing and CPET. Survival was analysed with Cox regression analysis (adjusted for age and gender) by age, comorbidity (Charlson-Index), body weight, body-mass index, extensive interstitial lung disease, pulmonary artery pressure (measured by echocardiography and invasively), and haemodynamic, pulmonary and CPET parameters. Results Five- and ten-year survival of SSc patients was 93.8 and 86.9%, respectively. There was no difference in survival between patients with diffuse (dcSSc) and limited cutaneous manifestation (lcSSc; p  = 0.3). Pulmonary and CPET parameters were significantly impaired. Prognosis was worst for patients with pulmonary hypertension ( p  = 0.007), 6-min walking distance < 413 m ( p  = 0.003), peakVO 2  < 15.6 mL∙kg − 1 ∙min − 1 , and VE/VCO 2 -slope > 35. Age (hazard ratio HR = 1.23; 95% confidence interval CI: 1.14;1.41), VE/VCO 2 -slope (HR = 0.9; CI 0.82;0.98), diffusion capacity (Krogh factor, HR = 0.92; CI 0.86;0.98), forced vital capacity (FVC, HR = 0.91; CI 0.86;0.96), and peakVO 2 (HR = 0.87; CI 0.81;0.94) were significantly linked to survival in multivariate analyses (Harrell’s C = 0.95). Summary This is the first large study with SSc patients that demonstrates the prognostic value of peakVO 2  < 15.6 mL∙kg − 1 ∙min − 1 (< 64.5% of predicted peakVO 2 ) and VE/VCO 2 -slope > 35.