A recent study using Swedish electronic health registries investigated whether patients with atrial fibrillation (A-fib) who take oral anticoagulants have a lower risk of developing dementia. Over 444,000 patients with A-fib – but no history of dementia – were included, with follow-up from 2006 through 2014. Just over half the patients were not on an anticoagulant; about 43% were taking warfarin; and 3% were taking a non-vitamin K oral anticoagulant (NOAC). Compared with patients who did not take anticoagulants, patients who were taking an anticoagulant had a 29% lower risk of developing dementia. The beneficial effect occurred with use of either warfarin or NOACs. Starting treatment soon after A-fib diagnosis (eg, within a month) appeared to have a greater protective effect than starting later.
The authors proposed that anticoagulants possibly minimize subclinical, small emboli over time and prevent microinfarctions that eventually lead to dementia. Protection against dementia may be a second benefit for anticoagulation in patients with A-fib.
• Fribert L, Rosenqvist M. Eur Heart J 2017; doi: 10.1093/eurheartj/ehx579.