Risk of Arterial Thrombotic Events in Inflammatory Bowel Disease

Abstract

Patients with inflammatory bowel disease (IBD) have an increased risk of venous thrombotic events. The risk of arterial thrombotic events in IBD, however, has been less well characterized. We explored whether Crohn's disease (CD) and ulcerative colitis (UC) are associated with a higher risk for thrombotic events involving the mesenteric, cardiac, or cerebral arteries. Using the Thomson Reuters MarketScan Research claims database, we conducted a retrospective cohort study of IBD patients observed for the occurrence of pre-defined thrombotic events. For comparison, four non-IBD controls were age-, sex-, and index date-matched to each IBD case. The outcomes of interest were acute mesenteric ischemia, transient ischemic attack, cerebrovascular occlusion, atherosclerosis, peripheral vascular disease, and myocardial infarction. We performed a multivariate analysis adjusting for potential confounders for thrombotic events, including hypertension, diabetes, hyperlipidemia, and, in women, the use of contraceptives. We calculated the adjusted hazard ratios (HRs) for each event by comparing IBD patients with controls and used the log-rank test to determine statistical significance. The study included 17,487 IBD patients and 69,948 controls. Overall, IBD patients had a markedly increased risk of acute mesenteric ischemia (HR=11.2, P<0.001). IBD patients as a whole did not have an increased risk of other arterial thrombotic events, including myocardial infarction and transient ischemic attack, when compared with controls. However, women with IBD who were over the age of 40 years had a higher risk of myocardial infarction (HR=1.6, P=0.003). In addition, women with IBD below the age of 40 years who showed a significantly higher risk for stroke (HR=2.1, P=0.04). For all events, the risks in CD and UC were similar. Patients with IBD have a markedly increased risk of acute mesenteric ischemia. Subgroup analysis reveals that women over the age of 40 years with IBD are at increased risk of myocardial infarction, whereas those below the age of 40 years exhibit a two-fold higher risk for stroke. In contrast, men with IBD did not share these same risks for arterial thrombotic events.