Patients living with both Alzheimer's disease and atrial fibrillation who took newer blood-thinning drugs known as NOACs declined more slowly on cognitive testing than comparable patients on other treatment paths, according to a study from Karolinska Institutet published in the European Heart Journal.
The research drew on SveDem, Sweden's national quality register for cognitive disorders and dementia, and covered 7,308 people carrying both diagnoses. Participants were sorted into three matched groups: those on NOACs, those on the older anticoagulant warfarin, and those taking no anticoagulant at all. Cognitive function was tracked over time with the Mini-Mental State Examination, the standard bedside test used in memory clinics worldwide.
Atrial fibrillation is one of the most common heart rhythm disorders in older adults, and it frequently coexists with Alzheimer's disease. Anticoagulants are prescribed to cut the risk of clots and stroke, and earlier work had hinted that such treatment might lower the odds of developing dementia in the first place. What has been far less clear is whether the drugs make any difference once Alzheimer's is already established - which is the gap this study set out to address.
Maria Eriksdotter, professor at the Department of Neurobiology, Care Sciences and Society at Karolinska Institutet and senior consultant in geriatric medicine at Karolinska University Hospital, who led the work, points to plausible biological reasons for the effect: better blood flow to the brain and less accumulation of small-scale vascular damage. For clinicians already weighing which anticoagulant to use in an older patient with both conditions, the findings add cognitive trajectory to the list of considerations, though the study reflects registry data rather than a randomized trial.