Background Systemic sclerosis (SSc) is known for its poor prognosis. However, it is apparent that subsets of patients have bad outcomes sometimes after a short time of disease duration whether some others will remain stable with a milder disease. The factors that have impact in the prognosis and mortality are yet to be determined.
Objectives To study the causes of dead and survival predictors in a Portuguese SSc population.
Methods Observational retrospective cohort study was performed including consecutive patients with clinical diagnosis of SSc (based on expert opinion), followed in our rheumatology department since 1990. Clinical and demographic characteristics were retrospectively collected by consulting the clinical files.
Patients who have died were compared with the others using Student t-test, Mann-Whitney test, Chi-square or Fisher test. Kaplan-Meier survival analysis and log rank were used to compare survival (SPSS 23.0). Significance level was set as <0.05.
Results 114 patients were included, 99 (86.8%) females and 15 (13.2%) males, with a mean age of 57.61 (±11.3) and a median disease duration of 7 years (0–38). 100 (87.7%) had localized and 14 (11.1%) had diffuse disease form.
The mortality rate observed was 1.1 cases per 100 person-years. Among the 10 patients that have died, 60% (6) were female, 60% (6) had diffuse and 40% (4) had limited skin involvement, and 20% (2) had overlap syndromes (1 overlap with rheumatoid arthritis and 1 with systemic lupus erythematosus). The median age was 63.5 [57 – 84] years and median disease duration was 10 [1–20] years.
The causes of death were: infections in 5 (3 sepsis, 1 septic arthritis, 1 pneumonia), cardiovascular events in 3 (right heart failure secondary to pulmonary arterial hypertension) and neoplasia in 2 (1 brain metastases of occult tumour and 1 gastric adenocarcinoma).
Mortality occurred more frequently in male patients (26.7% compared to 6% in females, p=0.03), in patients with diffuse skin involvement (40% compared to 4% in limited forms, p<0.001), digital ulcers (16.7% compared to 5%, p=0.04), pitting scars (20.6% compared to 3.8%, p=0.007), pulmonary arterial hypertension (50% compared to 6.5%, p=0.009), interstitial lung disease (19.2% compared to 5.7%, p=0.04) and anti-Scl70 antibodies (20.8% compared to 5.6%; p=0.03).
Kaplan-Meier univariate analysis showed a lower survival in patients with diffuse skin involvement (log rank 14.2 p<0.001), interstitial lung disease (log rank 6.3 p=0.04) and positive anti-Scl70 antibodies (log rank 6.4 p=0.04).
Conclusions Our results are in accordance with previous studies that show a high frequency of infections and cardiovascular events as major causes of death, but we also find malignancy as an important factor too. Diffuse skin disease, interstitial lung disease and positive anti Scl70 unfavourably influenced the survival and these patients are the ones in need for carefully evaluation and aggressive treatment.
Disclosure of Interest None declared