Anticoagulant drugs offer a protective effect against dementia as well as stroke in AF patients, and patients should be put on treatment as soon as possible to cut incidence, according to a study published in the European Heart Journal.
The study examined health registries of over 444,000 Swedish patients with AF, which spanned from 2006 to 2014.
Just under half of these were taking some form of anticoagulant – including warfarin, apixaban, dabigatran, edoxaban or rivaroxaban – at the start of the study.
The researchers found that those patients who were on treatment from the start of the study had a 29% lower risk of developing dementia compared with patients not on treatment – and this grew to a 48% reduction in the risk of dementia over the eight-year course of the study period.
Alongside lack of anticoagulant treatment, the study found that the strongest predictors of developing dementia among the patients were aging, Parkinson’s disease and alcohol abuse.
The retrospective nature of the study means it cannot show causal effect, but the researchers said the results strongly suggest oral anticoagulants protect against dementia in AF patients – and the sooner they are started following diagnosis, the greater their protective effect.
AF is known to carry an increased risk of stroke and dementia and although anticoagulants have been shown to reduce the likelihood of stroke, it is so far unclear whether they could also prevent dementia.
Lead author Dr Leif Friberg, from the Karolinska Institute, said the results showed it was important to ensure AF patients were taking anticoagulants as soon as possible after diagnosis.
He said: ‘Doctors should not tell their patients to stop using oral anticoagulants without a really good reason. Explain to your patients how these drugs work and why they should use them.
‘An informed patient who understands this is much more likely to comply and will be able to use the drugs safely and get better benefits.
‘Patients start on oral anticoagulation for stroke prevention but they stop after a few years at an alarmingly high rate. In the first year, approximately 15% stop taking the drugs, then approximately 10% each year.
‘In this study we found that only 54% of patients were on oral anticoagulant treatment. If you know that AF eats away your brain at a slow but steady pace and that you can prevent it by staying on treatment, I think most AF patients would find this a very strong argument for continuing treatment.
‘As a clinician I know there are AF patients who have a fatalistic view upon stroke. Either it happens or it does not. Few patients are fatalistic about dementia, which gradually makes you lose your mind.
‘In order to preserve what you´ve got, you should take care to use anticoagulants if you are diagnosed with AF, as they have been proved to protect against stroke and, which this study indicates, also appear to protect against dementia.’