Survival rate, causes of death, and risk factors in systemic sclerosis: a large cohort study

To investigate the clinical pattern, survival rate, causes of death and risk factors in a large cohort of Chinese Han patients with systemic sclerosis (SSc). Inpatients treated from 2002 to 2014 were included in this study. Patients were classified into diffuse cutaneous SSc (dcSSc), limited cutaneous SSc (lcSSc), and SSc-overlap syndrome groups. Data were analyzed using Chi-squared tests, Kaplan–Meier curves, log-rank tests, and Cox proportional hazards modeling. Among a total of 201 patients, dcSSc (50.2%) was the major subtype, followed by lcSSc (30.3%) and SSc-overlap (19.4%). Interstitial lung disease (ILD, 148/201, 74%) was the most frequent organ involvement. The overall survival rates were 98% and 95% at 5 and 10 years, respectively. The overall standard mortality ratio (SMR) was 2.22. The most common cause of death was ILD combined with infection (8/16, 50%), followed by kidney failure (2/16, 12.5%). On crude analysis, pulmonary hypertension, ILD, cardiac involvements, renal involvements, and digital ischemia were associated with poor prognosis. On multivariate analysis, pericardial effusion (p = 0.000) and digital ischemia (p = 0.016) were independent prognostic factors of death. The mortality rate of patients with SSc is mildly increased in comparison with the general population. ILD is the most common systemic involvement and the principal cause of death in SSc. Pericardial effusion and digital ischemia are independent factors associated with death.