Anticoagulants and Dementia: A Systematic Review

Many patients diagnosed with atrial fibrillation (AF) develop dementia. Most AF patients are also prescribed some antithrombotic medication to reduce the incidence of stroke, as clots can form within the left atrium. Some research has found that, excluding patients who have experienced strokes, anticoagulants may serve as protective agents against dementia in AF. This systematic review aims to analyze the incidence of dementia in patients who were prescribed anticoagulants. A comprehensive literature review was conducted using the databases PubMed, ProQuest, and ScienceDirect. Only experimental studies and meta-analyses were chosen. The search included the keywords "dementia and anticoagulant" and "cognitive decline and anticoagulants". Our initial search generated 53,306 articles, which were narrowed down to 29 by applying strict inclusion and exclusion algorithms. There was a decreased risk of dementia in patients who had been prescribed oral anticoagulants (OACs) in general, but only studies investigating direct oral anticoagulants OACs (DOACs) suggested that they were protective against dementia. Vitamin K antagonist (VKA) anticoagulants showed conflicting results, with some studies indicating they might increase the risk for dementia, while others suggested that they are protective against it. Warfarin, a specific VKA, was mainly shown to reduce the risk of dementia but was not as effective as DOACs or other OACs. Lastly, it was found that antiplatelet therapy may increase the risk of dementia in AF patients.