Impact of Anemia Management on Bleeding Outcomes in Anticoagulated Patients: A Retrospective Cohort Analysis.

Abstract

Anticoagulation therapy is essential to manage thromboembolic conditions such as atrial fibrillation and venous thromboembolism. While effective, it carries significant bleeding risks, with annual rates ranging from 10-17% for all events and 2-5% for major bleeding. Anemia is an independent risk factor for anticoagulation-associated bleeding; however, guidelines lack recommendations for anemia screening and management before initiation. In a retrospective analysis of 170 anticoagulated patients (mean age 63.7; 96 males, 74 females), 51.2% had baseline anemia. Anemia severity was significantly associated with bleeding events (χ²=15.7, p=0.003). Multivariate analysis confirmed that moderate (aOR=0.26, 95% CI:0.08-0.82, p=0.021) and no anemia (aOR=0.42, 95% CI:0.22-0.82, p=0.011) were associated with lower bleeding risk than mild anemia, while severe anemia remained uninterpretable due to small sample size. Patients aged ≥65 had higher bleeding risk (OR=2.8, 95% CI:1.5-5.1, p<0.01), though this did not reach significance in multivariate analysis (aOR=1.80, 95% CI:0.95-3.41, p=0.073). Multivariate analysis confirmed higher bleeding risks for warfarin (aOR=4.13, 95% CI:1.91-8.96, p<0.001) and rivaroxaban (aOR=3.67, 95% CI:1.69-7.97, p=0.001) compared to apixaban. Our study found an association between anemia and bleeding events, though severe anemia did not correlate with bleeding, possibly due to small sample size. Direct oral anticoagulants like apixaban and rivaroxaban present lower bleeding risks than warfarin. Given anemia's role in bleeding risk, we recommend routine screening before initiating anticoagulation to improve patient safety. Early assessment may help reduce bleeding complications, particularly in high-risk populations. Future studies should focus on multi-center trials to validate these findings and explore anemia subtypes.