POS0324 SMOKING HISTORY AND SCLERODERMA CLINICAL TRIALS CONSORTIUM DAMAGE INDEX (SCTC-DI) AS INDEPENDENT PREDICTORS OF MORTALITY IN SYSTEMIC SCLEROSIS IN A SINGLE-CENTRE ITALIAN COHORT

Abstract

Background:Systemic Sclerosis (SSc) is characterized by increased mortality and organ damage accrual. A composite SSc Damage Index was recently developed by the Scleroderma Clinical Trials Consortium (SCTC-DI) and was demonstrated as a predictor of mortality both in the Australian derivation cohort and in the Canadian validation cohort (1). Several independent predictors of mortality in SSc have been reported, but only limited data are available on the role of smoking.Objectives:To evaluate smoking history and SCTC-DI as independent predictors of mortality in SSc in a single centre Italian cohort.Methods:A retrospective analysis was performed on patients prospectively followed in our centre from 1989 to 2019, with at least 2 evaluations and/or cause of death available. Organ damage was evaluated through the SCTC-DI (0-55 scale; severe damage>12), while comorbidities through the Charlson Comorbidity Index (CCI). Survival analysis was performed with Kaplan-Meier curves and with Log-rank test to compare different subsets. Cox-regression analysis was performed to identify baseline independent predictors of mortality.Results:648 SSc patients were 99% Caucasian, 90% female and had a median age at diagnosis of 55.5 years (IQR: 45.0-65.6); 19% had diffuse cutaneous involvement. ACA was positive in 52%; anti-TopoI in 22% and anti-RNA Polymerase III in 5%.Median SCTC-DI at diagnosis was 2 (0-4) (n=560); ever smokers were 27%. During the follow-up 240 patients died after a median period of 10.2 years (4.9-16.8). The cause of death was related to SSc in 41% (n=65; most frequent causes pulmonary arterial hypertension (n=35) and interstitial lung disease (n=30)) and to other diseases in 40% (n=95; most frequent cause cancer (n=40)), while was indeterminate in 19%.Overall survival at 5, 10, 15, 20 years was 87.8% (SE 1.3%), 75.6% (1.9), 63.8% (2.3), 47.7% (2.8), respectively and was higher in females vs. males (p<0.0001) and in ACA+ vs ACA- (p=0.005), but did not differ between cutaneous subsets. 111 patients were lost at follow-up (17%).In the Cox-regression analysis smoking history and severe organ damage at diagnosis (score>12) were identified as independent predictors of death, while age at diagnosis, female gender, diffuse cutaneous subsets, ACA positivity and CCI were not (Table 1).Conclusion:Smoking history and severe organ damage were independent predictors of death in a large Italian single centre SSc cohort. SCTC-DI was confirmed as a useful tool to predict mortality at every timepoint