A Prospective Cohort Study on Warfarin Personalized Medication

Inclusion Criteria: * Patients aged 65 years and older, taking warfarin, with or without premature vascular aging, regardless of gender. * Patients who have not concurrently or intermittently used anticoagulant drugs, including antiplatelet drugs, heparin, low molecular weight heparin, and non-vitamin K-dependent oral anticoagulants, such as dabigatran and apixaban. * Signing an informed consent form before blood sample collection. Exclusion Criteria: * Patients who are allergic to warfarin or lactose. * Patients who are receiving immunosuppressive agents or low molecular weight heparin anticoagulants. * Patients with bleeding tendencies, blood disorders with platelet counts \> 400 × 10\^9 /L or \< 100 × 10\^9 /L, hemoglobin \> 169 or \< 100 g/L. * History of peptic ulcer disease. * Malignant tumors, severe multi-organ dysfunction or failure such as heart, liver, and kidney. * Neurological disorders such as epilepsy.