Alzheimer's - Dementia, Author Interviews, Heart Disease / 06.05.2016
Even on Anticoagulation Atrial Fibrillation Contributes to Dementia Risk
MedicalResearch.com Interview with:
T. Jared Bunch, MD
Director of Heart Rhythm Research
Medical Director for Heart Rhythm Services
Intermountain Healthcare System
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Bunch: Approximately 6 years ago we found that patients with atrial fibrillation experienced higher rates of all forms of dementia, including Alzheimers disease. At the time we started to ask the questions of why this association existed. We know that atrial fibrillation patients experience higher rates of stroke. These patients are placed on blood thinners, most commonly warfarin, to lower risk of stroke which at the same time expose that patient to a higher risk of intracranial bleeding. One possibility to explain the association was that perhaps dementia in the manifestation of many small clots or bleeds in the brain that in total lead to cognitive decline. If this is the case, then the efficacy and use of anticoagulation is very important in atrial fibrillation patients.
We conducted additional studies that showed this to be the case. In patients with no history of dementia, managed long-term with warfarin anticoagulation, those that had levels that were frequently too higher or too low that resulted in poor times in therapeutic range, experienced significantly higher rates of dementia. The risk was highest in younger atrial fibrillation patients that were less than 80 years of age. We then found that in atrial fibrillation patients that were frequently over anticoagulated and also use an antiplatelet agent, aspirin or plavix, the dementia rates nearly doubled. At this point we raised the question if atrial fibrillation increased the risk beyond anticoagulation, or does anticoagulation efficacy drive most of the risk. This question formed the background of the current study.
(more…)