Presentation: Risk Factors For Mortality In Patients With Systemic Sclerosis And Interstitial Lung Disease (2007)

6 Risk Factors For Mortality In Patients With Systemic Sclerosis And Interstitial Lung Disease

BACKGROUND. The outcome of patients with systemic sclerosis (SSc) and interstitial lung disease (ILD) is extremely variable. There are very mild forms with almost no clinical repercussion and minimal progression, whereas severe cases may rapidly progress to extensive lung fibrosis refractory to treatment, determining patient survival.
OBJECTIVE. To analyze possible risk factors for mortality in patients with SSc and ILD, that could be detected early in the disease course
PATIENTS AND METHODS. From 220 SSc patients (26m, 194f; 49±17y at diagnosis) followed in a university hospital during 30 years, those with ILD were selected. Confirmation of ILD diagnosis was made in every case by x-ray or high resolution CT-scan. Demographic data (age, gender, follow-up, death), clinical features (skin disease, ESR, lung, renal, cardiac, muscular, articular and gastrointestinal involvement) and data on treatment used, were obtained from previous data bases and from the patients charts. For statistics, bivariate odds ratio with 95% confidence interval (CI) to measure the strength of association between variables, Kaplan-Meier curves to estimate survival, and univariate and multivariate Cox proportional hazard analysis to study mortality associations, were used.
RESULTS. From 220 SSc patients, 79 (11m, 68f) had ILD. Age at initial symptom and diagnosis were 44±16 and 48±16y, respectively. Thirty nine patients had diffuse, 30 limited and 10 SSc in overlap. Main clinical characteristics were ischemic ulcers (53%), gastrointestinal (70%), cardiac (39%), muscular (19%) and renal involvement (8%). ESR was elevated in 24 (30%) patients, 30 (38%) had a-Scl70, 9 (11%) a-RNP y 11 (14%) a-centromere (2 cases with both). Fifty patients (63%) had been treated with immunosuppressive drugs (32 AZA, 21CFX). The overall survival for the group was 86% at 5 years and 70% at 10 years. Twenty five patients died, 10±8 years from diagnosis, 9 due to ILD and its complications and 7 due to cardiac causes. Mortality was associated with age over 30 years at initial SSc symptoms (OR 7.5, CI 1.025-62.08, p=0.04), FVC<80% (OR 6.7, IC 2.33-19.6, p<0.001), cardiac involvement (OR 3.1, IC 1.12-8.64, p=0.026), and elevated ESR (OR 6.07, IC 2.04-18.01, p=0.001) at the first visit. Risk factors associated with mortality, corrected for age, by univariate Cox analysis, were diffuse skin involvement (OR 1.04, CI 1.01-1.07, p=0.004), and elevated ESR (OR 2.89 IC 1.28-6.55, p=0.011), both at the first visit. Multivariate Cox confirmed these two features as independent mortality risk factors. A-Scl70 did not confer a poorer prognosis in our group of SSc patients with ILD.
CONCLUSIONS. Mortality in patients with SSc and ILD is increased in those with an early and severe impairment of pulmonary function, concomitant cardiac involvement and elevated ESR, but not in Scl-70 positive patients. Both diffuse skin disease and elevated ESR at disease onset, may identify those patients with ILD with higher risk for mortality, thus needing a more aggressive treatment.

 B.E. Joven, None; R. Almodovar, None; P.E. Carreira, None.