AFib Problems Are Not Confined to the Heart . . .

Atrial fibrillation (AFib) – an irregular, erratic heart rhythm – is an occasional cause of stroke.  Because the heart isn't pumping out regularly, blood can pool in the atria, and blood clots formed there may travel to the brain, blocking an artery and causing stroke.  But there are other effects in the brain that AFib can have, including an increased risk of dementia.  This is quantified in a study described in the Heart Rhythm Journal.   

Over 37,000 consecutive patients entering the Intermountain Heart Collaborative Study, based in Utah, were followed for the development of AFib and dementia over a 5-year period.  Their average age was 61. 

Twenty-seven percent of the enrollees developed AFib and 4.1% developed dementia.  Analyses showed that AFib patients younger than 70 were 2.3 times more likely to develop Alzheimer’s disease than those without AFib.  The actual frequency of Alzheimer’s in AFib patients was 1.5%, and in non-Afib patients 0.7%.  People with AFib in this age group were also more likely to develop other forms of dementia (vascular, senile, and non-specific).  Corresponding associations between AFib and dementias in higher age groups were weaker, and were non-significant by age 80-89.  A further analysis showed that the presence of AFib predicted a 38% to 45% increased mortality risk in patients with the different forms of dementia, compared to those without dementia. 

This study is not the first to demonstrate a link between AFib and dementia, but it’s the first to quantify the relationship.  Of course, it doesn’t establish a causal relationship, or the mechanism underlying such a link.  But it would be interesting to see if aggressive heart rhythm management and/or anticoagulation could improve the increased mortality risk, the researchers speculate.