Secondary stroke prevention with apixaban in nonvalvular atrial fibrillation: A subgroup analysis of the STANDARD study

BACKGROUND: Data on independent risk factors for stroke recurrence in Japanese patients with nonvalvular atrial fibrillation are limited. METHODS: We performed a subgroup analysis of a postmarketing surveillance study of apixaban (STroke prevention ANticoagulant Drug Apixaban Real-world Data study) in Japanese patients with nonvalvular atrial fibrillation receiving oral apixaban (5 mg/2.5 mg twice daily) in routine clinical practice. Patients were categorized into primary and secondary prevention groups based on the absence or presence of a history of ischemic stroke/transient ischemic attack, respectively. RESULTS: Patients in the secondary prevention group (1101 of 6306 patients [17.5%] analyzed; mean observation period, 15.7 months) had a higher risk of ischemic stroke or hemorrhage than those in the primary prevention group. The incidence rates of major (3.92%/year vs 2.06%/year), intracranial (1.87%/year vs 0.55%/year), and cerebral (1.14%/year vs 0.37%/year) hemorrhage and effectiveness outcomes (ischemic stroke/systemic embolism/transient ischemic attack, 3.25%/year vs 0.57%/year) were significantly higher (all P < 0.001) in the secondary prevention group than in the primary prevention group. Multivariate analysis identified no independent risk factors in the secondary prevention group, while prior major bleeding, alcohol abuse, advanced age, male sex, lower body weight, higher serum creatinine, and antiplatelet drug use were identified as risk factors for major hemorrhage, and advanced age and antiplatelet drug use for effectiveness outcomes in the primary prevention group. CONCLUSIONS: Among Japanese patients with nonvalvular atrial fibrillation who received apixaban, presence of a history of ischemic stroke/transient ischemic attack was associated with higher incidence rates of hemorrhage and thromboembolic events.