Stockholm, Sweden—Blood-thinning drugs appear to do far more than just reduce stroke risk in atrial-fibrillation (AF) patients.
A report in the European Heart Journal suggests anticoagulants also significantly reduce the risk of dementia.
Karolinska Institute researchers conducted a study involving 444,106 AF patients who were using anticoagulants and found their risk of developing dementia by the end of the study was 29% lower than those not on blood-thinner treatment.
As patients continued to take the drugs, the reduction in dementia risk grew to 48%, according to the report.
The retrospective study, touted as the largest of its kind, analyzed data from Swedish registries for patients between 2006 and 2014.
Study authors suggest that, based on the results, which cannot prove causal effect, there is reason to believe that oral anticoagulants have a protective effect against dementia in AF patients, explaining, “In order to prove this assumption, randomized placebo controlled trials would be needed, but... such studies cannot be done because of ethical reasons. It is not possible to give placebo to AF patients and then wait for dementia or stroke to occur.”
For the study, researchers identified all patients in Sweden who had a diagnosis of AF between 2006 and 2014—a time period in which 26,210 patients were diagnosed with dementia.
Noting that, at study initiation, 54% of patients were not taking oral anticoagulants such as warfarin, apixaban, dabigatran, edoxaban, or rivaroxaban, the researchers determined that the strongest predictors for dementia development were lack of oral anticoagulant treatment, aging, Parkinson’s disease, and alcohol abuse. In addition, they established, when starting oral anticoagulant treatment after a diagnosis of AF, earlier treatment was better in preventing dementia.
“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,” pointed out lead author Leif Friberg, MD, PhD. “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.”