Estimated glomerular filtration rate is a marker of mortality in the European Scleroderma Trials and Research Group (EUSTAR) database

Objectives: Study aim was to evaluate estimated glomerular filtration rate (eGFR), its association with clinical disease and its predictive ability with mortality in systemic sclerosis (SSc) patients from the European Scleroderma Trials and Research Group (EUSTAR) database. Methods: SSc patients from the EUSTAR database with available items for calculation of eGFR at baseline visit and with a second follow-up visit were included. A cut-off of 60 ml/min was chosen for all SSc patients and 30 ml/min for scleroderma renal crisis (SRC). Cox regression and competing risk analysis were performed to evaluate the role of eGFR as predictive factor of mortality. Results: 3650 SSc patients were included. Mean serum level of creatinine and eGFR were 0.8 mg/dl (IQR 0.6-0.9) and 86.6 ± 23.7 ml/min. The eGFR was significantly lower in patients with pulmonary hypertension. Overall survival (OS) was significantly reduced in SSc patients with eGFR <60 ml/min respect to patients with eGFR ≥ 60 ml/min [OS at five years 0.763 (CI 95%: 0.700-0.814) vs 0.903 (CI 95%: 0.883-0.919 p< 0.001)]. In multivariable analysis, OS was associate with male gender (p< 0.01), systolic pulmonary arterial pressure (sPAP) (p< 0.001) and eGFR (p< 0.001). Cumulative incidence of deaths due to SSc was associate with increased sPAP (p< 0.001) and reduced eGFR (p< 0.05). OS at five years of 53 SRC patients was not significantly different in SSc patients with eGFR > 30 ml/min or eGFR < 30 ml/min. Conclusion: eGFR represents a predictive risk factor of overall survival in SSc. The eGFR is not a risk factor for death in SRC.