People living with both Alzheimer's disease and atrial fibrillation declined more slowly on a standard memory test if they took newer NOAC blood thinners rather than warfarin or no anticoagulant at all.
The research
Researchers at Karolinska Institutet in Sweden, led by Maria Eriksdotter, a professor in the Department of Neurobiology, Care Sciences and Society and a senior consultant in geriatric medicine at Karolinska University Hospital, drew on SveDem, the Swedish national quality registry for cognitive disorders and dementia. Their findings appeared in the European Heart Journal.
The team identified 7,308 people diagnosed with both atrial fibrillation — a common heart rhythm condition in older adults — and Alzheimer's disease. Participants were sorted into three matched groups: one took newer direct oral anticoagulants known as NOACs, one took the older blood thinner warfarin, and one received no anticoagulant medication.
Cognition was tracked with the Mini-Mental State Examination (MMSE), a standardized test of orientation, memory and attention. Over follow-up, the NOAC group declined more slowly than both the warfarin group and the untreated group. Nanbo Zhu, a researcher in the same department, described the gap as "slightly more than 0.2 MMSE points per year" — small across twelve months, but potentially compounding over years.
The pattern extended beyond thinking and memory. Compared with people taking no anticoagulants, those on NOACs also had lower risks of death, stroke, blood clots and fractures. Warfarin was likewise tied to lower risks of death, stroke and blood clots, but carried a higher risk of major bleeding.
Why it matters
Atrial fibrillation and Alzheimer's frequently overlap in older adults, which makes the question of which anticoagulant to use a daily clinical decision rather than a rare one. Eriksdotter notes there are plausible mechanisms: better blood flow and less small-vessel damage in the brain. But she and her colleagues are explicit that this was an observational study — it cannot show that NOACs caused the slower decline. Unmeasured factors may have influenced both which drug a patient received and how their health unfolded, and some participants switched medications during follow-up. Think of this as a signal worth confirming in randomized trials, not a reason to change a prescription on your own.
What you can do
- If you or a family member has both atrial fibrillation and cognitive concerns, ask a clinician whether anticoagulant choice is worth reviewing.
- Track cognition over time with the same test rather than relying on memory of how sharp you felt last year.
- Keep standard heart-health basics in place: blood pressure, activity, sleep and medication adherence.
Source: ScienceDaily Mind & Brain
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