Risk of dementia lower for Afib patients on anticoagulants

Atrial fibrillation (Fib) was associated with an increased risk of dementia in the elderly, but anticoagulants may have reduced this risk, according to a longitudinal study conducted in Sweden.

Afib was associated with faster cognitive decline and vascular and mixed dementia, according to Mozhu Ding, of the Karolinska Institute in Stockholm, and his colleagues.

But patients with Afib under anticoagulants had a 60% lower risk of incident dementia than patients with untreated Afib, they reported. Neurology.

"Our findings show a clear link between atrial fibrillation, cognitive decline and dementia, while many previous studies have provided inconsistent results," said Ding. MedPage today. "In addition, our study is one of the first to report that the use of an anticoagulant could prevent dementia in people with atrial fibrillation."

The results echo the findings of a retrospective Swedish study from last year: a registry analysis showing that Afib patients on oral anticoagulation were less likely to develop dementia over time.

As part of the Swedish National Study on Aging and Care in Kungsholmen, researchers studied 2,685 elderly people with dementia, collecting data and establishing diagnoses of dementia through diabetes. face-to-face interviews, clinical examinations and laboratory tests. 5.8 years old. The average age of reference was 73.1 years and 62.9% were women.

Initially, 243 people (9.1%) had atrial fibrillation. During the follow-up period, an additional 279 (11.4%) developed atrial fibrillation and 399 (14.9%) developed dementia.

The value of atrial fibrillation was significantly associated with a faster annual decrease in the Mental State Examination Minimum (MMSE) (beta -0.24, 95% CI of -0.31 to -0.16) and at an increased risk of all-cause dementia 1.40, 95% CI 1.11-1.77) and vascular and mixed dementia (HR 1.88, 95% CI 1.09-3.23), but not the Alzheimer's disease (HR 1.33, 95% CI 0.92-1.94).

Among Afib patients, dementia occurred in 76 out of 22 (22%) who did not use anticoagulants and 14 out of 11 (11%) who used it (HR 0.40, 95% CI) , 18-.92). There was no risk of reduced dementia in patients who used antiplatelet drugs.

Subclinical brain infarctions may contribute to the association between atrial fibrillation and cognitive decline, said Luciano Sposato, MD, of the Western University in London, Ontario, Canada, and Lin Chen, MD, from the University of Minnesota to Minneapolis, in an accompanying editorial.

Researchers, however, have difficulty demonstrating that anticoagulants have a definite advantage for the prevention of dementia in Afib patients: a randomized controlled trial may be unethical because of the substantial risk of reducing the number of patients. 39; ischemic ACV associated with anticoagulation.

This leaves observational studies, which are subject to bias, including confusion by indication. "Oral anticoagulants are less likely to be prescribed to patients with cognitive impairment, likely because of the risk of potential noncompliance perceived by the physician or due to patients' medication errors," observed Sposato and Chen. And unlike a cerebrovascular event, it may be difficult to identify a specific moment of onset of dementia.

Unmeasured confusion is a major gap in this study, which could result from the limited number of variables in proportional correlation regression analyzes, they added.

Ding and colleagues reported other limitations: they could not distinguish Afib subtypes and the MMSE may have underestimated cognitive decline. The study focused mainly on highly educated Caucasians from an urban district and the findings might not apply to other populations.

2018-10-10T16: 00: 00-0400