P583. Venous thromboembolism in Asian patients with inflammatory bowel disease
Patients with inflammatory bowel disease (IBD) have an apparent increased risk of venous thromboembolism (VTE) with the majority of VTE occurring during active disease. Antithrombotic prophylaxis has been recommended in all hospitalised patients with IBD. The prevalence of VTE in IBD ranges from 1.2 to 6.7% in clinical studies; in a recent study of 2784 IBD patients, prevalence and incidence rate of all VTE was 5.6% and 6.3 per 1000 person-years respectively. Most studies were however conducted in western populations, and there is limited data available in Asian patients. Our aim is to evaluate the risk of VTE in Asian patients with IBD in Singapore, a multiracial country consisting largely of Chinese, Malays and Indians.
Case notes and electronic records of patients with ulcerative colitis (UC) or Crohn's disease (CD) who were treated at our centre from 2002 to 2013 were retrospectively reviewed. Medical records were then extracted for biodata, progress, treatment and thromboembolic complications of disease. The diagnosis of VTE is according to international guidelines and appropriate imaging techniques. Padua prediction score was used to stratify the risk of developing VTE. Incidence rates were calculated based on person-years of follow-up from 2002–2013.
Of the 152 patients with IBD, 96 had UC and 56 had CD: of which 94 were male (62%) with a median age of 48 (range 17–90). There were 93 Chinese (61%), 40 Indians (26%), 16 Malays (11%) and the remaining 2% were of other Asian ethnicities. This is a fair representation of local demographics. Disease severity was highly variable, as was modality of treatment. 31 (33%) UC patients and 29 (52%) CD patients had 161 (91 CD, 70 UC) hospitalisation episodes for flare of disease. The median number of hospitalisation episodes was 1.5 (range 1–7) for UC flare and 1 (range 1–17) for CD flare. None of the patients were given antithrombotic prophylaxis during hospitalisation. None of the ambulatory IBD patients developed VTE. Among hospitalised IBD patients, only 1 CD (Padua score 0: low risk) and 1 UC patient (Padua score 5: high risk) developed pulmonary embolism and bilateral deep vein thrombosis respectively; both VTEs were detected during their first hospitalisation and initial diagnosis of IBD. Thrombophilia screens were negative. The period prevalence and incidence rates for all VTE, DVT and PE were 1.31%, 0.65%, 0.65% and 1.20, 0.60 and 0.60 per 1000 patient-years respectively.
The risk of VTE in Asian patients with IBD appears to be lower than that in western populations. Further larger prospective studies are needed to better assess the risk of VTE and the role of routine antithrombotic prophylaxis in Asian patients with IBD.