Diagnostic yield of upper gastrointestinal tract endoscopy and colonoscopy in patients with iron deficiency anaemia while on direct oral anticoagulants.

Abstract

Background: Iron deficiency anaemia (IDA) related to occult gastrointestinal tract (GIT) blood loss is associated with high rates of GIT malignancies. Major society guidelines recommend bidirectional endoscopic evaluation for all men and post-menopausal women with newly diagnosed, unexplained IDA. However, in patients prescribed direct oral anticoagulants (DOACs), the endoscopic yield, specifically the rate of high-risk findings, including colorectal cancers (CRCs) and advanced adenomas (AAs), is unknown.

Aim: Our aim is to determine the endoscopic yield, specifically the prevalence of these high-risk findings in patients presenting with new-onset unexplained IDA while on a DOAC.

Methods: This is a single-centre, retrospective analysis performed at a tertiary hospital in Australia. Between January 2015 and July 2019, 178 consecutive patients underwent endoscopic evaluation for IDA while prescribed a DOAC. Patient demographics, laboratory data, medications and endoscopic findings were summarised and compared by diagnostic yield. Associations were explored using logistic regression analysis.

Results: CRCs were present in 2/178 (1.1% (95% confidence interval (CI): 0.1-4.0)) patients. AAs were found in 35/178 (19.6% (95% CI: 14.1-26.3)) patients. The most common AAs were tubular adenomas (45.7%), tubulovillous (31.4%) and sessile serrated adenomas (14.2%). Older age (P = 0.013) and lower ferritin levels (P = 0.009) were associated with the presence of high-risk findings.

Conclusion: In patients presenting with new-onset, unexplained IDA while on a DOAC, the prevalence of CRCs is lower than previously reported in studies involving populations not prescribed DOACs. Conversely, there is a higher incidence of AAs, including high-risk histological features, such as tubulovillous adenomas and sessile serrated polyps.