Pulmonary arterial hypertension (PAH), peripheral arterial disease, the presence of Scl-70 antibodies, and anticardiolipin antibodies are independent predictors of venous thromboembolism (VTE) in patients with systemic sclerosis (SSc), although SSc does not independently confer increased risk for VTE, according to the results of a cohort study published in The Journal of Rheumatology.
The study participants were selected from the Toronto Scleroderma Program, a health network comprised of 3 hospitals. The study enrolled 1181 patients, including 971 women and 210 men, who met the American College of Rheumatology/European League Against Rheumatism classification criteria for SSc admitted to the hospital between 1970 and 2017. Participants with localized scleroderma, overlap syndromes, undifferentiated connective tissue disease, and inherited thrombophilia were excluded from the study.
A total of 40 patients experienced VTE events, 20 experienced deep vein thrombosis events, 26 had a pulmonary embolism, and 6 experienced both deep vein thrombosis and pulmonary embolism. The prevalence of VTE was 2.71 per 1000 patients (95% CI, 1.9-3.7), which revealed no significant difference compared with the general population’s 2 cases per 1000 people (P =.07).
Subgroup analyses revealed that VTE prevalence appeared to increase with age, which is similar in the general population. In addition, the prevalence of VTE in African Americans appeared to be higher compared with whites or Asians. Men and women did not appear to have a different prevalence of VTE.
During the course of the study, 440 patients died. Although there was no significant difference in short-term survival between the VTE and non-VTE groups (log-rank test, P =.54), results suggested worsening long-term survival in the VTE group. However, there was no significant difference in the unadjusted survival between the two groups (hazard ratio [HR], 1.16; 95% CI, 0.70-1.91).
While the authors noted that vascular abnormalities in SSc “provide a plausible biologic rationale for the development of VTE” and thus “it has been suggested that SSc is an underrecognized risk factor for VTE,” they found that the supporting evidence is limited.
Johnson SR, Hakami N, Ahmad Z, Wijeysundera DN. Venous thromboembolism in systemic sclerosis: prevalence, risk factors, and effect on survival [published online April 15, 2018]. J Rheumatol. doi:10.3899/jrheum.170268