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/m2). 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.