Obscure gastrointestinal bleeding: Which factors are associated with positive capsule endoscopy findings?

Background: Capsule endoscopy is a first line examination to evaluate obscure gastrointestinal bleeding. The identification of factors associated with the detection of lesions by capsule endoscopy could improve resource utilization and patient selection. Objectives: To identify factors associated with positive capsule endoscopy findings in patients with obscure gastrointestinal bleeding. Methods: Retrospective, single-center study, including 203 patients (214 capsule endoscopy procedures) submitted to capsule endoscopy in the setting of obscure gastrointestinal bleeding. Type of obscure gastrointestinal bleeding, number of units of packed red blood cells transfused, type of positive finding, number of endoscopy studies performed prior to capsule endoscopy, comorbidities, medication and Charlson index were evaluated. Overt bleeding was subdivided into ongoing and previous gastrointestinal bleeding. Only lesions with high hemorrhagic potential (P2) were classified as positive findings. Results: The mean age was 62.2 years and 59.7% of patients were female. Most patients were referred for occult gastrointestinal bleeding (64.5%), while 35.5% were referred for overt gastrointestinal bleeding (63.2% previous-overt gastrointestinal bleeding). The most frequent positive findings included ulcers/erosions (34%) and angioectasias (32%). In univariate analysis, the identification of positive findings was significantly higher in those with ongoing-overt bleeding (p < 0.001), advanced age (p = 0.003), increasing number of pre-capsule endoscopies (p < 0.001), increasing transfusion requirements (p < 0.001), moderate/severe renal disease (p = 0.009) and antiplatelet drugs (p = 0.021) and NSAID intake (p = 0.005). In multivariate analysis, positive findings were significantly higher only in those with ongoing-overt bleeding (odds ratio [OR] 18.68, 95% confidence interval [CI] 3.98-85.6, p < 0.001), higher transfusion requirements (OR 1.23, 95% CI 1.1-1.4, p < 0.001) and NSAID intake (OR 5.9,95% Cl 2.1-17.3, p = 0.001). Conclusions: Capsule endoscopy should be used early in obscure gastrointestinal bleeding. Ongoing-overt bleeding, higher transfusion requirements and NSAIDs intake were associated with positive findings on capsule endoscopy.