Patients diagnosed with systemic sclerosis (SSc) may have a three times greater risk of venous thromboembolism (VTE) – including potentially deadly clots in the lungs – and an increased risk in the first year after a diagnosis, according to a large population database study from Canada.
The study, published in the July 20, 2015 issue of Arthritis Care & Research, of 1,245 SSc patients (83% female, mean age 56 years old),and 12,670 matched controls in British Columbia (BC), attributes the increased risk to vascular damage from SSc-related fibrosis that causes endothelial dysfunction and hypercoagulability due to inflammation.
Vasculopathy and vascular injury may be more prominent in the early stages of the autoimmune disease (also called scleroderma) – as seen in the incidence of Raynaud’s phenomenon, the researchers suggest.
The study reveals a hazard ratio (HR) of 32.77 for VTE in the year after an initial diagnosis of SSc -- with HRs of 8.50 for pulmonary embolism (PE) and 12.03 for deep vein thrombosis (DVT).
While the risk of such dangerous clots declines over five years of follow-up, it is significant. “Increased monitoring for this potentially fatal outcome and its modifiable risk factors is warranted in this patient population,” the authors write.
Preventive treatment typically includes anticoagulants, such as warfarin, or newer drugs.
The study shows an increased incidence of PE, DVT and VTE among SSc patients, with incidence ratios (IR) of 3.47, 3.48 and 6.56 per 1000 person-years respectively versus 0.78, 0.76, and 1.37 per 1000 person-years among 12,670 non-SSc individuals.
The study is limited by its observational nature, the researchers note.
Schoenfeld SR, Choi HK, Sayre EC, Aviña-Zubieta JA. The risk of pulmonary embolism and deep venous thrombosis in systemic sclerosis: A general population-based study. Arthritis Care & Research. 2015. Accepted article. Online First, 20 July 2015. DOI: 10.1002/acr.22673