Pos0836 Organ Damage Accrual and One-Year Mortality in Systemic Sclerosis: A Prospective Observational Study

Background: Systemic sclerosis (SSc) is a clinically heterogeneous and pathogenically complex disease where disease activity and damage can occur simultaneously, making it challenging to distinguish between both processes. However, discriminating and assessing activity and damage is crucial for determining prognosis and evaluating therapeutic needs in an individual patient, yet this remains an area of deficiency in SSc. In 2019, an international consortium developed a new specific instrument for SSc, the Scleroderma Clinical Trials Consortium Damage Index (SCTC-DI), based on 23 weighted items that predict morbidity and mortality. This damage index has only been retrospectively validated thus far. Objectives: The objectives of this study were to determine cumulative organ damage in SSc patients according to the SCTC DI, assess one-year mortality risk, and identify associated factors. Methods: The study began with a single-center cohort of consecutively recruited SSc patients (ACR/EULAR 2013 criteria) followed in our unit. Patients were monitored every 3 to 6 months in specific consultations, and all patients were recorded in a database. A cross-sectional cut was performed on the cohort between May and November 2022, and during prospective follow-up, mortality for any cause at 12 months was collected. All patients provided written consent. Variables: The main variable was cumulative damage caused by SSc according to the SCTC DI and mortality from any cause. Other demographic, clinical-analytical variables, modified Rodnan Skin Score (mRSS), SCTC DI and its domains, quality of life according to EQ-5D, and Steinbrocker functional status were recorded. Statistical Analysis: Descriptive, bivariate, and multivariate analyses were conducted to assess factors associated with permanent organic damage caused by SSc. Results: Seventy-five patients participated (97.3% females, 85.3% Caucasians) with a mean (SD) age of 59.6 (20.7) years. The median (p25-p75) duration of SSc was 6 (2-13) years. Fourteen (18.7%) patients had diffuse cutaneous SSc, and 61 (81.3%) had limited cutaneous SSc. The frequency of autoantibodies was: 72/75 patients had positive ANA, 17/75 anti-Scl70, 42/75 anticentromere, 10/75 anti-Ro, 3/75 anti PM/Scl, 3/75 anti-RNP, 2/75 anti-RNA polymerase III, and 1/75 anti-Ku. The median (p25-p75) mRSS was 8 (2-13), C-reactive protein (CRP) was 4 (4-6) mg/L, and SCTC DI was 4 (0-6). Fifty-four (72.0%) patients had a low SCTC DI (≤5), 15 (20.0%) had a moderate (between 6 and 12), and 6 (8.0%) had severe SCTC DI. Domains affected by organic damage in the cohort are shown in Figure 1. After one year of follow-up, 4 SSc patients died from different causes: septic shock of respiratory origin, lung cancer, COVID-19 pneumonia, and the last, with severe myocardiopathy and pericardial effusion, died at home while sleeping. Patients with an SCTC DI ≥13 at baseline had a RR of death of 1.9 (95% CI 0.7-5.0) compared to those with mild or moderate organic damage (SCTC DI ≤12). A multivariate linear regression analysis (adjusted R2=0.628) highlighted that SCTC DI was directly associated with mRSS (β=0.266; B=0.141 95% CI 0.029 – 0.253 p=0.014), duration of SSc in years (β=0.234; B=0.116 95% CI 0.026 – 0.205 p=0.012), positive anti-Scl70 (β=0.183; B= 2.555 95% CI 0.152 – 4.958 p=0.037), and CRP (β=0.325; B= 0.199 95% CI 0.088 – 0.311 pConclusion: The SCTC DI can be a useful tool in clinical practice to assess disease progression and short-term mortality risk. Variables most associated with cumulative damage are mRSS, disease duration, presence of anti-Scl70, and CRP levels. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.