Bleeding During Anticoagulation for Atrial Fibrillation and Subsequent Malignancy

Bleeding during anticoagulation for atrial fibrillation might be the first sign of occult cancer (J Am Heart Assoc 2020; 9:e016836). In a new study, researchers identified 120,000 older patients (age, ≥66; median age, 77) in Ontario who received vitamin K antagonists (e.g., warfarin) or direct-acting oral anticoagulants (DOACs) for atrial fibrillation between 2008 and 2022. A total of 69% of patients received DOACs; use of P2Y12 inhibitors (e.g., clopidogrel), but not aspirin, was recorded.

Bleeding occurred in 22% of patients during the 2 years after starting anticoagulation, with higher risk in those who received vitamin K antagonists than in those who received DOACs. Malignancies were diagnosed in ≈5% of patients, and bleeding was associa…