"Blood thinners are often prescribed to prevent strokes in people with the abnormal heart rhythm known as atrial fibrillation. But a new study suggests these drugs may also help keep dementia at bay. The researchers said that the key is to start blood thinners such as warfarin soon after atrial fibrillation is diagnosed. Thats true even for people at low risk of a stroke who wouldnt normally be given blood thinners.  We found that people who are on warfarin  the most common blood thinner used to prevent stroke in patients with atrial fibrillation  experienced very low rates of dementia including Alzheimers disease said lead researcher Dr. T. Jared Bunch. Hes director of heart rhythm research at Intermountain Medical Center Heart Institute in Murray Utah.  Atrial fibrillation is a common heart abnormality that affects nearly  million American adults. It causes the heart to beat abnormally or quiver. This causes blood to pool and then it can clot.  Atrial fibrillation can cause dementia by damaging tiny blood vessels in the brain through repeated tiny clots or small bleeds that people arent even aware of Bunch explained.  While many patients are initially given aspirin Bunch said aspirins benefit in cutting the risk for dementia is limited and patients should be started on warfarin or another blood thinner.  Although the study looked at patients taking warfarin Coumadin newer drugs  including rivaroxaban Xarelto and apixaban Eliquis  should reduce the risk of dementia even more Bunch said.  In patients with atrial fibrillation the risk of stroke is usually measured using the socalled CHADS score the researchers said. This score assigns points for several risk factors such as age high blood pressure heart disease diabetes and a previous stroke. A score of zero to one usually means blood thinners arent needed because the risk for stroke is low. For patients with scores above one blood thinners are considered necessary as these patients are judged to be at moderate to high risk according to the researchers.  In this study however the investigators said they found that even a short delay in giving blood thinners to patients at low risk for stroke increases the risk for dementia.  In patients considered at lowrisk for stroke delaying bloodthinning treatment increased the risk for dementia  percent. In highrisk patients a delay increased the risk  percent the researchers reported.  The longer the delay in giving blood thinners the more the risk for dementia the researchers said.  For the study Bunch and his colleagues looked at information from more than  atrial fibrillation patients who had no history of dementia. The average age of the study participants was  and  percent were male. The researchers looked at when treatment began either within  days of atrial fibrillation diagnosis which was considered immediate or after a year which was considered delayed.  Once you are diagnosed with atrial fibrillation starting strokeprevention strategies immediately is essential. We shouldnt wait longer than a month to begin treatment Bunch said. The delay in treating can be devastating to patients when they start developing mental decline years later he added.  The results of the study were scheduled for presentation Friday at the meeting of the Heart Rhythm Society in Chicago. Findings presented at meetings are generally viewed as preliminary until theyve been published in a peerreviewed journal. According to Dr. Byron Lee of the University of California San Francisco UCSF There is a growing body of literature supporting the connection between atrial fibrillation and dementia. Lee is a professor of medicine and director of the electrophysiology laboratories and clinics at UCSF. Therefore he said we need to be extremely aggressive in treating atrial fibrillation patients with anticoagulants blood thinners when indicated. This study shows that treatment delays of even one month can greatly increase the incidence of cognitive mental decline Lee said. More information For more on atrial fibrillation visit the American Heart Association http_UCM__Article.jsp. SOURCES T. Jared Bunch M.D. director heart rhythm research Intermountain Medical Center Heart Institute Murray Utah Byron Lee M.D. professor of medicine director electrophysiology laboratories and clinics University of California San Francisco May   presentation Heart Rhythm Society meeting Chicago"