Maeda T, Nishi T, Funakoshi S, et al. - In this large-scale observational study with Japanese patients with atrial fibrillation who were not on anticoagulants, researchers assessed the incidence of ischemic stroke as well as bleeding events (intracranial hemorrhage, gastrointestinal bleeding, others) depending on CHA2DS2-VASc scores in these patients in a real-world setting. Health checkups and insurance claim data were collected from a Japanese insurance organization. Based on patients’ CHA2DS2-VASc scores (range 0–≥3), the risk levels were described: low, intermediate, or high risk was considered in men with scores of 0, 1, or ≥ 2 and women with scores of 1, 2, or ≥ 3, respectively. A mean 2.5-year follow-up was performed. For ischemic stroke and for total bleeding events, the annual event rates were estimated to be 0.58% and 1.17%, respectively. Overall, findings revealed high risks of ischemic stroke and bleeding events, especially in those exhibiting high CHA2DS2-VASc scores.