Venous Thromboembolism in Systemic Sclerosis: Prevalence, Risk Factors, and Effect on Survival

Objective Whether systemic sclerosis (SSc) confers increased risk of venous thromboembolism (VTE) is uncertain. We evaluated the prevalence, risk factors, and effect of VTE on SSc survival.

Methods A cohort study was conducted of subjects with SSc who fulfilled the American College of Rheumatology/European League Against Rheumatism classification criteria between 1970 and 2017. Deep vein thrombosis was defined as thrombus on extremity ultrasound. Pulmonary embolism was defined as thrombus on thorax computed tomography angiogram. Risk factors for VTE and time to all-cause mortality were evaluated.

Results Of the 1181 subjects, 40 (3.4%) experienced VTE events. The cumulative incidence of VTE was 2.7 (95% CI 1.9–3.7) per 1000 patient-years. Pulmonary arterial hypertension (PAH; OR 3.77, 95% CI 1.83–8.17), peripheral arterial disease (OR 5.31, 95% CI 1.99–12.92), Scl-70 (OR 2.45, 95% CI 1.07–5.30), and anticardiolipin antibodies (OR 5.70, 95% CI 1.16–21.17) were predictors of VTE. There were 440 deaths. There was no difference in survival between those with and without VTE (HR 1.16, 95% CI 0.70–1.91). Interstitial lung disease (HR 1.54, 95% CI 1.27–1.88) and PAH (HR 1.35, 95% CI 1.10–1.65) were predictors of mortality.

Conclusion The risk of VTE in SSc is comparable to the general population. The presence of PAH, peripheral arterial disease, Scl-70, and anticardiolipin antibodies are risk factors for VTE. VTE does not independently predict SSc survival.