Association of Aspirin Use with Reduced Risk of Developing Alzheimer’s Disease in Elderly Ischemic Stroke Patients: A Retrospective Cohort Study

Background: Currently there are no effective therapies to prevent or halt the development of Alzheimer’s disease (AD). Multiple risk factors are involved in AD, including ischemic stroke (IS). Aspirin is often prescribed following IS to prevent blood clot formation. Observational studies have shown inconsistent findings with respect to the relationship between aspirin use and the risk of AD. Objective: To investigate the relationship between aspirin therapy after IS and the new diagnosis of AD in elderly patients. Methods: This retrospective cohort study leveraged a large database that contains over 90 million electronic health records to compare the hazard rates of AD after IS in elderly patients prescribed aspirin versus those not prescribed aspirin after propensity-score matching for relevant confounders. Results: At 1, 3, and 5 years after first IS, elderly patients prescribed aspirin were less likely to develop AD than those not prescribed aspirin: Hazard Ratio = 0.78 [0.65,0.94], 0.8 1 [0.70,0.94], and 0.76 [0.70,0.92]. Conclusion: Our findings suggest that aspirin use may prevent AD in patients with IS, a subpopulation at high risk of developing the disease.