Cognitive Function and Anticoagulation Control in Patients With Atrial Fibrillation

Background— Patients with atrial fibrillation usually are elderly and may have cognitive dysfunction. These patients may receive less effective oral anticoagulation, resulting in more vascular events and bleeding. Methods and Results— In an analysis of cognitive function associated with the time in therapeutic range (TTR) in the Atrial Fibrillation Clopidogrel Trial With Irbesartan for Prevention of Vascular Events, 2510 patients (mean age, 71±9.5 years) from 27 countries completed the Mini-Mental State Examination (MMSE). Of these patients, 171 (6.8%) had an MMSE score <24, suggesting dementia, and 194 (7.7%) had intermediate scores of 24 to 25. Low MMSE scores were correlated with a low TTR. Even mild cognitive impairment was associated with a TTR below the median (<65%). Patients with an MMSE score <26 had more vascular events (6.7% versus 3.6% per 100 patient-years; P=0.002) and more bleeding (9.6% versus 7% per 100 patient-years; P=0.04). After controlling for TTR, the MMSE no longer conferred increa...