Mortality in Systemic Sclerosis-Associated Interstitial Lung Disease in Brazil: A Real-Life, Long-Term Follow-up Observational Study.

Abstract

The aim of this study was to identify risk factors associated with mortality in patients with systemic sclerosis (SSc), particularly those with interstitial lung disease (ILD), over a long-term follow-up in a large Brazilian SSc cohort. We conducted a medical records review study of 380 scleroderma patients from 1982 to 2019. Systemic sclerosis ILD was considered in those with evidence of ILD on chest high-resolution computed tomography (HRCT). Causes of death were determined. Among the 380 SSc patients, SSc-ILD on chest HRCT was observed in 227 patients (59.7%). Seventy-two patients (18.9%) died during a mean follow-up of 7.2 years since the SSc diagnosis; among them, 57 (79.2%) had SSc-ILD, compared with 15 (20.8%) without SSc-ILD (p < 0.001). Of the 72 deaths, 51.4% were considered related to SSc, and ILD was the leading cause of death. The overall survival rates at 5, 10, and 15 years were 87.9%, 81.5%, and 74.9%, respectively. Kaplan-Meier analysis showed a significantly worse prognosis among patients with SSc-ILD than among those without ILD (p < 0.001). Among patients with SSc-ILD, disease duration of less than 4 years (p < 0.001), forced vital capacity <80% at baseline (p = 0.017), and pulmonary systolic arterial pressure ≥40 mm Hg on echocardiography (p < 0.001) were significantly associated with mortality by multivariate analysis. In Brazilian SSc patients, the presence of ILD was associated with a worse prognosis. The higher mortality among SSc-ILD patients, especially those with a shorter disease duration and forced vital capacity <80%, highlights the need for early screening and closer monitoring before irreversible lung function deterioration occurs.