Atrial Fibrillation Linked to Increased Dementia Risk in Stroke Patients

Researchers at the University of East Anglia (Norfolk, United Kingdom) conducted a meta-analysis of data--obtained from Medline, Embase, and PsychINFO during September 2010--from published prospective studies reporting on the association between baseline AF and incident dementia. The researchers identified 15 such studies, including a total of 46,637 participants with a mean age of 71.7 years. Pooled odds ratios for AF and dementia were calculated using the random effects model in 14 studies that could be pooled.

The results showed that when the researchers stratified studies by whether participants had had a prior stroke, the relationship with AF became highly significant with little heterogeneity. For other populations, the association between AF and dementia was only of borderline significance, again with substantial heterogeneity. For conversion of mild cognitive impairment to dementia, one study showed a significant association with AF. The study was published in the March 8, 2011, issue of Neurology.

"Intuitively you would think that vascular dementia would be more likely to be linked to atrial fibrillation, and maybe that's why the evidence is stronger in stroke patients with atrial fibrillation compared to the general population,” said study coauthor Phyo Kyaw Myint, MD, of the health and social science research institute. "But having said that, we need to know more about whether this link exists for both major types of dementia, Alzheimer's disease and vascular dementia, that will need a more rigorously designed study.”

Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging. It may be static, the result of a unique global brain injury, or progressive, resulting in long-term decline due to damage or disease in the body. Although dementia is far more common in the geriatric population, it may occur in any stage of adulthood. Without careful assessment of history, the short-term syndrome of delirium (often lasting days to weeks) can easily be confused with dementia, because they have all symptoms in common, save duration. Some mental illnesses, including depression and psychosis, may also produce symptoms that must be differentiated from both delirium and dementia.

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