Bleeding complications in patients with gastrointestinal cancer and atrial fibrillation treated with oral anticoagulants

BACKGROUND: Direct oral anticoagulants (DOACs) may increase the risk of gastrointestinal (GI) bleeding in patients with atrial fibrillation (AF) and GI cancer compared with vitamin K antagonists (VKA). METHODS: We conducted a Danish nationwide cohort study comparing the bleeding risk associated with DOAC versus VKA in patients with AF and GI cancer. We calculated crude bleeding rates per 100 person‐years (PYs) for GI and major bleeding. We then compared rates of bleeding at 1 year after initial oral anticoagulation filled prescription by treatment regimen using inverse probability of treatment weighting and Cox regression. RESULTS: The unweighted study population included 1476 AF patients with GI cancer (41.6% women, median age 78 years) initiating a DOAC and 652 initiating a VKA. One‐year risk of GI bleeding was 5.0% in the DOAC group and 4.7% in the VKA group with a corresponding weighted hazard ratio (HR) of 0.95 (95% confidence interval [CI]: 0.63, 1.45). For patients with active cancer, weighted GI bleeding rates were slightly higher in both the VKA and DOAC group, and the weighted HR was 1.00 (95% CI: 0.53, 1.88). The HR was 1.12 (95% CI: 0.71, 1.76) for all bleedings. Hazard ratios for GI bleeding were 0.61 (95% CI: 0.25, 1.52) for patients with upper GI cancer, and 0.92 (95% CI: 0.58, 1.46) in patients with colorectal cancer. CONCLUSION: Evidence from this nationwide cohort study suggests a comparable 1‐year risk of bleeding associated with DOAC compared with VKA among patients with AF and GI cancer.