Real-world safety and clinical outcomes of apixaban in patients with cancer and atrial fibrillation

Background Patients with cancer and atrial fibrillation (AF) are at increased risk of both thromboembolism and bleeding. However, real-world data evaluating apixaban use in this population remain limited, particularly in Middle Eastern populations. Methods We conducted a retrospective observational cohort study at a tertiary care center in Saudi Arabia, including adult patients with active cancer or a history of malignancy who received apixaban for non-valvular atrial fibrillation (NVAF) with or without venous thromboembolism (VTE) between August 2016 and October 2020. Thrombotic and bleeding outcomes were assessed within 6 months of apixaban initiation. Baseline demographic and clinical characteristics, cancer-related variables, concomitant therapies, thrombotic events, bleeding outcomes, mortality, and apixaban discontinuation were descriptively analyzed. Bleeding events were classified according to the International Society on Thrombosis and Hemostasis criteria. Results The final analysis included 72 patients. The mean age was 71.0 ± 9.7 years, and 46 patients (63.9%) were female. Active cancer was present in 65 patients (90.3%), while solid tumors accounted for 76.9% of malignancies. Thrombotic events occurred in 7 patients (9.7%), including ischemic stroke in 3 patients and deep vein thrombosis in 3 patients. Bleeding events occurred in 26 patients (36.1%), including major bleeding in 7 patients (9.7%). The most commonly reported bleeding sites were the upper airway and gastrointestinal tract. During follow-up, 21 patients (28.8%) died, most commonly from cancer-related causes. Excluding treatment cessation at the time of death, apixaban was clinically discontinued in 19 patients (26.4%). Documented clinical reasons for discontinuation included bleeding complications, breakthrough thrombotic events requiring a change in anticoagulation therapy, thrombocytopenia, high bleeding risk, and extreme obesity (BMI >50 kg/m 2 ). Conclusion Thrombotic and bleeding events were common in this real-world cohort of patients with cancer and AF receiving apixaban. These findings highlight the complexity of anticoagulation management in this high-risk population and support the need for close clinical monitoring and further prospective studies.