Increased Risk of Venous Thromboembolism in Systemic Sclerosis

Patients with incident systemic sclerosis (SSc) may have an increased risk of venous thromboembolism (VTE) within the first year of diagnosis, according to recent data published in Arthritis Care & Research.¹

Researchers used a population database that included all residents of British Columbia, Canada, to create a cohort of 1245 patients with incident SSc and an additional cohort of 12 670 patients without SSc. They compared the incidence rates of pulmonary embolism (PE), deep vein thrombosis (DVT), and venous thromboembolism (VTE) between these 2 cohorts according to SSc disease duration to determine the risk of the general population.

“Overall, we observed a 3-fold increased risk of PE, DVT, and VTE in SSc patients compared to those without SSc, independent of relevant risk factors such as age, sex, history of hospitalization, and overall comorbidity index,” the authors wrote. “Our findings provide general population-based evidence that SSc, regardless of prior hospitalization, is associated with a substantially increased risk of PE and DVT, and they lend insight into the relative risks over the duration of SSc.”

The incidence rates of PE, DVT, and VTE among individuals with SSc were 3.47, 3.48, and 6.56 per 1000 person-years, respectively. Furthermore, the rates of PE, DVT, and VTE among the patients without SSc were 0.78, 0.76, and 1.37 per 1000 person-years, respectively.

When compared to individuals without SSc, the hazard ratio (HR) among SSc patients for PE was 3.73 (95% confidence interval [CI], 1.98-7.04), 2.96 for DVT (95% CI, 1.54-5.69), and 3.47 for VTE (95% CI, 2.14-5.64).

The researchers observed that the time-matched HRs for PE (HR: 32.77; 95% CI, 6.60-162.75), DVT (HR: 8.50; 95% CI, 3.14-23.04), and VTE (HR: 12.03; 95% CI, 5.27-27.45) were significantly higher during the first year after diagnosis.

The authors noted that the 3-fold increased risk of VTE among all SSc patients warrants further research to look into the risks of specific VTE subsets.

“These findings support increased monitoring and vigilance for VTE risk factors among patients with SSc, regardless of recent hospitalization, to help avoid this potentially devastating outcome,” they concluded.

Summary and Clinical Applicability

Researchers in this study observed a 3-fold increased risk of PE, DVT, and VTE among all SSc patients within their first year of diagnosis. Many rheumatologic diseases are inflammatory in nature, with active inflammation causing a prothrombotic state characterized by upregulation of tumor necrosis factor alpha (TNF-α) and activation of endothelial cells. Although inflammation is a recognized risk factor for many rheumatic diseases, as well as for VTE, rheumatic diseases are not always recognized as a risk factor for hypercoagulability.²  Further research is necessary to identify which patients are at the highest risk of developing VTE, with subsequent consideration of initiation of antiplatelet prophylaxis or reduction in disease activity.

References

1. Schoenfeld SR, Choi HK, Sayre EC, Avina-Zubieta JA. Risk of pulmonary embolism and deep venous thrombosis in systemic sclerosis: a general population-based study. Arthritis Care Res. 2016;68(2):246-253. doi: 10.1002/acr.22673.

2. Lee JJ, Pope JE. A meta-analysis of the risk of venous thromboembolism in inflammatory rheumatic diseases. Arthritis Res Ther. 2014;16(5):435. doi: 10.1186/s13075-014-0435-y.