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

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 to evaluate 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).

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 of follow-up after diagnosis; 3) available follow-up visits at predefined timepoints.

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, the 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 the 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, the SCTC-DI score was demonstrated to be significantly higher at the baseline and at every timepoint, with a higher annual rise.

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.