Long-term organ damage accrual and late mortality in systemic sclerosis

Objectives: Progressive organ damage accrual in patients with systemic sclerosis (SSc) can be measured using the Scleroderma Clinical Trials Consortium Damage Index (SCTC-DI). We aimed at the evaluation of the long-term evolution of organ damage accrual in SSc patients with at least 10 years of follow-up, identifying clinical and laboratory features associated with moderate and severe damage, and the association of SCTC-DI with "late mortality" (death >10 years after diagnosis). Methods: In this single-centre retrospective study, patients with SSc were included when fulfilling the following characteristics: 1) a baseline visit corresponding to the time of diagnosis; 2) a minimum of 10-years follow-up after diagnosis; 3) available follow-up visits at predefined timepoints. Results: In 253 patients included in the study, SCTC-DI progressively increased from the baseline to 10 years after diagnosis, with 34% of patients showing moderate or severe damage at this time point. During the follow-up, SCTC-DI score was higher, and had a higher annual rise, in dcSSc patients than in lcSSc and in ACA-negative patients than in ACA+. Multivariable analyses identified dcSSc, lack of ACA, and SCTC-DI scores at previous timepoints as independent variables associated with moderate or severe damage. In patients with "late mortality", as compared to surviving patients, SCTC-DI score was demonstrated to be significantly higher at the baseline and at every timepoint, with a higher annual rise. Conclusions: Factors associated with damage accrual in SSc patients with long-term follow-up were identified. Higher SCTC-DI and higher SCTC-DI annual rise were associated with late mortality in SSc.