Relationship of low-dose aspirin to GI injury and occult bleeding: a pilotstudy

Background: Low-dose aspirin is commonly used in patients with cardiovascul ar disease. However, little is known about the effect of aspirin on occult blood loss caused by gastrointestinal injury. Therefore, we studied endosco pic injury and fecal occult blood loss in patients ingesting different quan tities of low-dose aspirin. Methods: Forty healthy volunteers were enrolled in a randomized, double-bli nd, prospective, pilot endoscopic study. Each volunteer underwent 30 days o f treatment with daily aspirin 30 mg, 81 mg, 325 mg, or placebo. Subjects c ompleted fecal occult blood test cards before and at the end of treatment o f two types: guaiac impregnated (Hemoccult and Hemoccult SENSA) and immunoc hemical (HemeSelect and FlexSure OBT). Each volunteer underwent upper endos copy at baseline and after completing 30 days of study medication. Results: Aspirin did not induce significant injury as determined by endosco py when compared with placebo. Six of 30 volunteers taking aspirin develope d erosions, whereas 1 of 10 subjects on placebo developed a new erosion (p = 0.66). Aspirin 325 mg was associated with a higher mean symptom score tha n the lower aspirin dosages and the placebo group (p = 0.12). Only one subj ect taking aspirin (325 mg) had fecal occult blood on a single HemeSelect c ard. No subject had a positive fecal occult blood test with Hemoccult II, H emoccult II SENSA, or FlexSure OBT cards. Conclusions: Aspirin in dosages commonly used for cardiovascular prophylaxi s does not generally cause significant gastric or duodenal mucosal endoscop ic lesions. In the absence of frank ulceration, low-dose aspirin does not r esult in positive fecal occult blood tests. Low-dose aspirin should not int erfere with fecal occult blood testing and probably should not be stopped d uring stool collection.