The BRAIN-AF study is a multicenter randomized clinical trial focused on patients with atrial fibrillation and a low risk of thromboembolic events. It compared treatment with the anticoagulant rivaroxaban with a placebo. The goal was to check the prevention of ischemic stroke and neurocognitive damage. Treatment with rivaroxaban showed no benefit in reducing cognitive decline compared with placebo. There was also no reduction in the incidence of stroke or transient ischemic attack. The study was published in Nature Medicine online on January 7, 2026.