Venous Thromboembolism in Inflammatory Bowel Disease: An Epidemiological Review

OBJECTIVES: This article aims to review the evidence implicating inflammatory bowel disease (IBD) as a risk factor for the development of venous thromboembolic events (VTEs), as well as to highlight additional risk factors and preventative and treatment strategies relating to the VTEs in IBD patients. METHODS: Medline and Embase databases were systematically searched and all original articles pertaining to VTEs in IBD patients were evaluated for suitability of content and methodology. RESULTS: Multiple large studies have demonstrated that IBD patients have a 1.5- to 3.5-fold higher risk of incurring VTEs when compared with non-IBD patients. A large population-based study showed that IBD activity is associated with the development of VTEs. Although the greatest relative increase in the risk of VTEs with disease activity was observed in ambulatory IBD patients, hospitalized IBD patients had a markedly higher baseline risk of VTEs than ambulatory patients. Among VTE-related hospitalizations, the presence of IBD was associated with a 2.5-fold increased risk of mortality in one population-based study. No studies have specifically evaluated the potential benefit of VTE prophylaxis in hospitalized or ambulatory IBD patients. Studies to date do not support an increased bleeding risk with moderate doses of anticoagulant medications in IBD patients with active disease. CONCLUSIONS: IBD patients are at an increased risk of sustaining VTEs and may be at an increased risk of VTE-related mortality when compared with non-IBD patients. IBD activity is an independent risk factor for VTE development. Future large prospective studies are required to better assess risk factors, health outcomes, and prevention strategies associated with the development of VTEs in IBD patients.