Thromboembolic events and cardiovascular mortality in inflammatory bowel diseases: A meta-analysis of observational studies

Objective: Patients with inflammatory bowel disease (IBD) are at increased risk of having venous thromboembolism. The magnitude of this risk has yet to be determined. The question of whether IBD patients have an increased risk of arterial thromboembolism and cardiovascular (CV) mortality remains controversial. Design: We searched MEDLINE, Cochrane Library, EMBASE and international conference abstracts and included all controlled observational studies that evaluated the incidence of venous and/or arterial thromboembolic events (TE) and CV mortality in adult IBD. Results: 33 studies enrolling 207,814 IBD patients and 5,774,898 controls and capturing 3,253,639 hospitalizations of IBD patients and 936,411,223 hospitalizations of controls reported a risk of arterial and/or venous TE or CV mortality were included. The risk of venous TE was increased in IBD patients compared to the general population (RR, 1.96; 95% CI, 1.67-2.30) contrary to the risk of arterial TE (RR, 1.15; 95% CI, 0.91-1.45). There was an increased risk of deep venous thrombosis (RR, 2.42; 95% CI, 1.78-3.30), pulmonary embolism (RR, 2.53; 95% CI, 1.95-3.28), ischemic heart disease (RR, 1.35; 95% CI, 1.19-1.52) and mesenteric ischemia (RR, 3.46; 95% CI, 1.78-6.71). Differences in methodology were great between studies resulting in a significant heterogeneity in all previous analysis. CV mortality in IBD patients was not increased compared to the general population (SMR, 1.03; 95% CI, 0.93-1.14). Conclusion: The risk of TE is increased in patients with IBD. This difference is mainly due to an increased risk of venous TE. There is no increased risk of arterial TE or CV mortality in IBD patients, but an increased risk of both ischemic heart disease and mesenteric ischemia.