Proximal predominance of small bowel injury associated with uncoated low-dose aspirin therapy

BACKGROUND AND AIM: Only a limited number of studies have evaluated the small intestinal damage associated with chronic low-dose aspirin (LDA) therapy. We assessed, using capsule endoscopy, the prevalence and the characteristics of small bowel damage in chronic LDA users compared with patients taking an anticoagulant (AC) and those taking no antithrombotic drugs. PATIENTS AND METHODS: We retrospectively reviewed 75 capsule endoscopy recordings from three groups of patients with unexplained iron-deficient anemia: 28 patients receiving LDA, 15 receiving an AC, and 32 not receiving any antithrombotic drug. The severity and location of small intestinal mucosal breaks were assessed in a blinded manner by two endoscopists. RESULTS: All LDA users received uncoated aspirin. The number of small bowel mucosal breaks in patients receiving LDA (median 1, extremes 0-125) was significantly higher than that in those taking an AC (0, 0-1) (P=0.0005) or no antithrombotic drugs (0, 0-23) (P<0.0001). The prevalence of patients with mucosal breaks was higher in the LDA group (71.4%) than in the AC group (20%, P=0.001) and the control group (12.5%, P=0.000005). Mucosal breaks in LDA users were predominant in the first tertile of the small bowel. The difference between groups was significant only for mucosal breaks located in the first tertile (P<0.0001). CONCLUSION: About two-thirds of uncoated LDA chronic users with anemia have mucosal breaks in the small bowel. These lesions are predominant in the proximal part, suggesting a topical toxic effect of uncoated LDA.