Drug Taken for Common Condition May Be Slowing Alzheimer’s Decline

A new study from Karolinska Institutet in Sweden suggests that a widely used blood-thinning medication may be slowing the progression of cognitive decline in individuals with both atrial fibrillation and Alzheimer's disease. The study, published in the European Heart Journal, found that patients treated with newer blood thinners known as NOACs (direct oral anticoagulants) experienced a significantly slower rate of cognitive decline compared to those on older blood thinners like warfarin or no treatment at all.

Maria Eriksdotter, a professor at Karolinska Institutet who led the research, explained that the treatment could potentially benefit cognition by improving blood flow and reducing small-scale damage in the brain. Atrial fibrillation, a common heart rhythm disorder among older adults, often co-occurs with Alzheimer's disease. Typically, doctors prescribe blood-thinning medication to atrial fibrillation patients to reduce their risk of blood clots.

While earlier research hinted that anticoagulant treatments might lower the risk of developing dementia, scientists had limited knowledge about how these drugs affect individuals already diagnosed with Alzheimer's.

The researchers analyzed data from SveDem, Sweden's national quality register for cognitive disorders and dementia, focusing on 7,308 individuals diagnosed with both atrial fibrillation and Alzheimer's disease. Participants were divided into three groups: those taking NOACs, those on warfarin, and those receiving no anticoagulant medication.

Cognitive function was monitored using the Mini-Mental State Examination (MMSE), a standard test assessing memory and thinking skills. Patients on NOACs demonstrated a slower cognitive decline, with their MMSE scores decreasing by approximately 0.2 points per year compared to those on warfarin or no treatment.

The benefits of NOACs extended beyond cognitive function. Patients treated with NOACs had a lower risk of death, stroke, blood clots, and fractures compared to those receiving no anticoagulant treatment. Warfarin, while also associated with reduced risks of death, stroke, and blood clots, came with a higher risk of major bleeding than NOACs.

Dr Mohammad Bakhtiar, an English-based general practitioner, commented on the study's findings, stating that the large sample size of over 7,000 people provides strong evidence against dismissing the results as mere noise. He believes the findings offer encouraging evidence for the use of newer anticoagulants over warfarin in individuals with both atrial fibrillation and Alzheimer's disease.

However, the researchers caution that the study is observational and cannot definitively prove that the drugs directly cause the slower decline in cognitive function. Various factors, such as differing patient profiles and medication switches during the study, may have influenced the observed outcomes. Bakhtiar emphasizes that while the results are promising, more research is needed to establish a causal relationship.

He advises patients not to make any changes to their current medications based solely on this study. The research was funded by various organizations, including the Swedish Research Council, the Swedish Brain Foundation, CIMED, ALF project funding, and Karolinska Institutet.