P1151 Incidence and risk factors of thromboembolic events in Pediatric-Onset Inflammatory Bowel Disease: a population-based study

Abstract

Abstract Background Patients with inflammatory bowel disease (IBD) are known to be more susceptible to thromboembolic events. However, limited data on the incidence and risk factors for both venous (VTE) and arterial thromboembolic events (ATE) have been documented at the population level, especially in pediatric-onset IBD. Methods All patients diagnosed with Crohn’s disease (CD) or ulcerative colitis (UC) before the age of 17 years from 1988 to 2011 in a prospective population-based registry were retrospectively followed until 2013. Every VTE and ATE occurring during the follow-up period were included. Cox proportional hazard models with hazard ratio (HR) were performed using time dependent variable except for patient’s characteristics at diagnosis. Results A total of 1,344 patients diagnosed with IBD between 1988 and 2011, including 1,007 (75%) patients with CD and 337 (25%) with UC, with a median age at diagnosis of 14.3, IQR [11.7-16.0] years were included. After a median follow-up of 8.3, IQR [4.3–13.9] years, 15 (1.1%) VTE and 2 (0.15%) ATE occurred at a median age of 20.4, IQR [16.6-24.5] years (younger age: 14.8 years). The global incidence rate for both VTE and ATE was 1.32 per 1000 person-years, 95%CI [0.77 - 2.11]. In CD patients, the incidence of VTE was 1.41 per 1000 person-years, 95%CI [0.77 - 2.37], whereas it stood at 0.33 per 1000 person-years, 95%CI [0.01 - 1.85] in UC patients. The risk of VTE and ATE did not change over the study period. Periods of active disease (HR 8.4 [2.3-30.5], p=0.0002), the 3-months postoperative period (HR 16.4 [5.2-52.3], p=0.0002) and hospitalization (HR 21.7 [7.5-62.9], p<0.0001) were found to be associated with an increased risk of VTE. Conclusion The risk of both arterial and venous thromboembolism was low in this pediatric-onset IBD population-based cohort. VTE were strongly associated with active disease, surgery and hospitalization among IBD patients.