Blood Thinners May Slow Cognitive Decline in Alzheimer's Patients With AFib

A study published in August 2026 in the European Heart Journal found that a class of blood thinners called NOACs may slow cognitive decline in people who have both Alzheimer's disease and atrial fibrillation.

Researchers at the Karolinska Institutet in Sweden, led by Professor Maria Eriksdotter and researcher Nanbo Zhu, analyzed data from 7,308 individuals in the Swedish national quality register for dementia care. All participants had been diagnosed with both atrial fibrillation and Alzheimer's disease.

Participants treated with non-vitamin K antagonist oral anticoagulants, known as NOACs, showed a slower decline in cognitive function by approximately 0.2 points per year on the Mini-Mental State Examination compared to those taking warfarin or no blood thinners.

Beyond cognitive benefits, NOAC users also showed a lower risk of stroke, death, blood clots, and fractures compared to those receiving no treatment. Warfarin was associated with reduced risks of death, stroke, and blood clots, but carried a higher risk of major bleeding compared to NOACs.

Researchers suggested that NOACs may improve blood flow and reduce small-scale brain damage caused by micro-emboli, tiny clots that form due to the irregular heart rhythm associated with atrial fibrillation.

The study is observational, meaning it shows an association rather than a direct cause-and-effect relationship. External experts, including Dr. Mohammad Bakhtiar, cautioned that factors such as overall patient health or differences in medical care could influence the results. Doctors advised patients not to change their current medication regimens without consulting their physicians.