Cognitive Screening as a Gateway to Cerebral Microbleed Detection in Atrial Fibrillation: The DAME Study

Atrial fibrillation (AF) and dementia prevalence increase with age. For patients with both co-morbidities, oral anticoagulation (OAC) reduces ischemic stroke risk, but augments intracranial hemorrhage (ICH) risk, especially for dementia from cerebral amyloid angiopathy (CAA). Thus, AF patients with CAA face a therapeutic dilemma: take OAC with elevated ICH risk or withhold OAC and increase ischemic risk. Screening AF outpatients for dementia remains unexplored. The DAME-Detect study (Dementia in Atrial fibrillation with Micro-bleeds Early Detection) was a prospective, interdisciplinary, longitudinal cohort study to assess co-morbid CAA and AF in cardiology clinics. After informed consent, patients/proxy completed the SED-11Q (Symptoms of Early Dementia-11 Questionnaire) and vascular neurologists reviewed subjects' brain MRIs. At 90-day follow-up, SED-11Q and OAC prescriptions were re-assessed. DAME-Detect enrolled 122 patients (68% male; mean age 77.5 years); 21 (17.2%) screened dementia-positive on SED-11Q while 101 (82.8%) screened dementia-negative. Of the 53 (43.0%) respondents at 90-day follow-up, 15.0% screened dementia-positive, of whom 62.5% had cerebral microbleeds (CMBs) on brain MRI, vs 13.3% of the 85.0% who screened dementia-negative (P = 0.012). Although antiplatelet use was similar (62.5% vs 66.7%, P = 0.999), OAC was significantly less in dementia-positive subjects (25.0% vs 86.7%, P < 0.001). In this prospective study, one-sixth of AF patients screened dementia-positive in cardiology clinic, two-thirds of whom had microbleeds on brain MRI. Dementia-positive patients were prescribed OAC less, presumably reflecting ICH concern. Dementia screening for AF patients in cardiology clinics is feasible and may enable OAC risk stratification. Future studies are warranted to explore alternatives (ie, Left atrial appendage closure) in this vulnerable population.