Salt Lake City, UT—Atrial fibrillation patients using warfarin are at higher risk for dementia than those using the blood thinner for other conditions.
That’s according to a study of more than 10,000 patients treated long term with warfarin presented at Heart Rhythm 2016, the Heart Rhythm Society's 37th Annual Scientific Sessions.
Researchers at the Intermountain Medical Center Heart Institute in Salt Lake City report that AFib patients, who generally were older, had higher rates of overall dementia (5.8% vs. 1.6%), Alzheimer's disease (2.8% vs. 0.9%), and vascular dementia (1.0% vs. 0.2%) compared to those with other issues requiring anticoagulation.
Background information in the article notes that AFib can increase the risk of dementia because it raises the risk of both large and small blood clots that can affect brain function. At the same time, blood thinners raise the possibility of both large and small brain bleeds, which also can affect cognitive function over time.
For the study, researchers from the Intermountain Healthcare Clinical Pharmacist Anticoagulation Service enrolled 10,537 adult anticoagulation patients with no prior history of dementia. In addition to AFib, the patients were being treated for conditions such as valvular heart disease and thromboembolism on a long-term basis.
During a follow-up of approximately 7 years, researchers found that all types of dementia increased in the atrial fibrillation group more than the non-AFib group, although the risk of dementia increased in both groups as the time in therapeutic range decreased or became more erratic.
Researchers suggest that the efficacy of therapy is strongly associated with dementia, adding that, in a surprising finding, patients younger than 70 years tended to be the most susceptible to the risk of cognitive decline.
“Our study results are the first to show that there are significant cognitive risk factors for patients treated with warfarin over a long period of time regardless of the indication for anticoagulation,” said lead researcher T. Jared Bunch, MD,
Bunch recommended in an Intermountain press release that “only those that absolutely need blood thinners should be placed on them long-term. Second, other medications like aspirin that may increase the blood thinners effect should be avoided unless there is a specific medical need. Finally, in people that are on warfarin in which the levels are erratic or difficult to control, switching to newer agents that are more predictable may lower risk.”
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