Prognostic value of cardiopulmonary exercise testing in patients with systemic sclerosis.

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), peakVO2 < 15.6 mL∙kg- 1∙min- 1, and VE/VCO2-slope > 35. Age (hazard ratio HR = 1.23; 95% confidence interval CI: 1.14;1.41), VE/VCO2-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 peakVO2 (HR = 0.87; CI 0.81;0.94) were significantly linked to survival in multivariate analyses (Harrell's C = 0.95). This is the first large study with SSc patients that demonstrates the prognostic value of peakVO2 < 15.6 mL∙kg- 1∙min- 1 (< 64.5% of predicted peakVO2) and VE/VCO2-slope > 35.