Clinical presentation of venous thromboembolism in inflammatory bowel disease.

BACKGROUND AND AIMS Patients with inflammatory bowel disease (IBD) are at increased risk of venous thromboembolism (VTE), but data on frequency, site of thrombosis and risk factors are limited. We sought to determine prevalence, incidence as well as location and clinical features of first VTE among IBD patients. METHODS We evaluated a cohort of 2811 IBD patients for a history of symptomatic, objectively confirmed first VTE, recruited from 14 referral centers. Patients with VTE before IBD diagnosis or cancer were excluded. Incidence rates were calculated based on person-years from IBD diagnosis to first VTE or end of follow-up, respectively. RESULTS 2784 patients (total observation time 24,778 person-years) were analyzed. Overall, of 157 IBD patients with a history of VTE, 142 (90.4%) had deep vein thrombosis (DVT) and/or pulmonary embolism (PE), whereas 15 (9.6%) had cerebral, portal, mesenteric, splenic or internal jugular vein thrombosis. The prevalence and incidence rate of all VTE was 5.6% and 6.3 per 1000 person years, respectively. Patients with VTE were older at IBD diagnosis than those without VTE (34.4±14.8years vs 32.1±14.4years, p=0.045), but did not differ regarding sex, underlying IBD and disease duration. 121 (77.1%) VTE were unprovoked, 122 (77.7%) occurred in outpatients and 78 (60.9%) in patients with active disease. Medication at first VTE included corticosteroids (42.3%), thiopurines (21.2%), and infliximab (0.7%). CONCLUSION VTE is frequent in IBD patients. Most of them are unprovoked and occur in outpatients. DVT and PE are most common and unusual sites of thrombosis are rare.