Across 347,128 primary-prevention patients followed a median 7.9 years, 2.4% received a dementia diagnosis and 2.0% an Alzheimer's dementia diagnosis. High baseline ASCVD risk raised dementia hazard 2.59-fold. Among high-risk patients, aspirin (low dose HR 0.88; high dose HR 0.83) and moderate-to-high-intensity lipid-lowering therapy (HR 0.85 for dementia and for Alzheimer's) were associated with fewer diagnoses.
The risk gradient is the sturdy part: cardiovascular risk scores double as dementia risk scores, reinforcing the vascular contribution to cognitive decline. The drug associations deserve far more caution. This is a retrospective health-system registry, and dementia was captured by diagnosis codes, which undercount mild disease and track healthcare contact. Confounding by indication cuts both ways: statin and aspirin users may be more engaged with care, which favors earlier diagnosis, or healthier, which favors fewer diagnoses. Aspirin's tidy signal in high-risk patients sits awkwardly against randomized evidence. ASPREE found no dementia benefit from low-dose aspirin in older adults, and aspirin is no longer recommended for routine primary prevention in many older patients because of bleeding risk. Randomized statin trials likewise have not shown clear cognitive protection. Treat this as hypothesis-generating and confirmatory of the vascular-risk link, not a reason to start aspirin for the brain. The practical takeaway is to manage ASCVD risk factors, including LDL and blood pressure, with your clinician, and to discuss aspirin only where cardiovascular indications justify it.