Utah researchers have found a link between a common form of heart disorder and the most common type of dementia, raising questions about the possibility that treating the heart could prevent Alzheimer's.

Doctors and scientists at Intermountain Medical Center say they are the first to show in a large study that patients with atrial fibrillation are at a greater risk of developing the brain disease, marked by loss of memory and other cognitive functions. They will present their findings today at the Heart Rhythm Society's scientific meeting in Boston.

According to the American Heart Association, atrial fibrillation is a type of arrhythmia in which the heart's two small upper chambers quiver instead of beating properly, raising the risk that the blood will pool, clot and cause a stroke.

"It really raises the question: If we can treat atrial fibrillation, if we can prevent it, can we prevent Alzheimer's from developing in the future?" asked cardiologist John Day, director of heart rhythm services at IMC and co-author of the study, which has been submitted for publication in the journal Circulation .

Using a database of 37,000 patients in the Intermountain Healthcare system, the study found patients with the heart disorder were 44 percent more likely to develop any type of dementia. Heart disease patients under age 70 were 130 percent more likely to develop Alzheimer's. And patients with both dementia and atrial fibrillation were 61 percent more likely to die within five years than patients without the heart problem.

The study doesn't reveal why the heart patients are at greater risk of dementia, but the researchers have some guesses: The arrhythmia leads to strokes, eventually leading to cognitive decline. High blood pressure could be behind both the heart problems and dementia.

"We have enough to start questioning our approach to patients with atrial fibrillation," said IMC cardiologist T. Jared Bunch, the study's lead author.

Day said the typical treatment is to put patients on blood thinners to minimize the risk of strokes. There are more aggressive treatment options, including radio-frequency ablation to destroy certain heart muscle cells and eliminate the arrhythmia. IMC and the University Hospital perform the procedure.

"It's a huge leap to say it would prevent Alzheimer's," Day acknowledged.

Other studies have shown links between dementia and heart disease, including high cholesterol levels being associated with increased risk of developing Alzheimer's.

"This study helps us realize that Alzheimer's disease is clearly a disease of the entire organism, not just the brain," said Jack Jenks, executive director of the Alzheimer's Association, Utah Chapter, in a written statement. "We are in an exciting era in which science is putting these relationships and systems together. We now know that what we do for the heart and for general health will benefit the brain as well."

hmay@sltrib.com