Association between cognitive impairment and risk of atrial fibrillation: The Atherosclerosis Risk in Communities study

Background: Atrial fibrillation (AF) is reportedly a risk factor for cognitive impairment. Interestingly, recent studies have emphasized that impaired cognition is probably an initiating factor of cardiovascu- lar disease. Thus, we aimed to explore the association between impaired cognition and the risk of AF, and clarify the potential mechanisms. Methods: Participants of visit 2 (1991-1993) in the Atherosclerosis Risk in Communities study were included. Global cognition z-scores and factor scores were calculated using the word fluency, delayed word recall, and digit symbol substitution tests. AF incidents were diagnosed by electrocardiography and inpatient records. The association of cognitive decline with AF risk and left atrial volume index (LAVI) was explored using Cox proportional hazards and linear regression models, respectively. Results: During the median follow-up of 18.2 +/- 6.2 years, 2056/11,675 (17.6%) participants devel- oped AF. Participants in the lowest quartile of global cognition z-scores and factor scores had a higher risk of AF (hazard ratio [HR]: 1.271, 95% confidence interval [CI]: 1.094-1.477, p = 0.002; HR: 1.305, 95% CI: 1.110-1.535, p = 0.001, respectively) than those in the highest quartile. Global cogni- tion z-scores and factor scores were negatively correlated with the LAVI (B: -0.411, 95% CI: -0.749 to -0.074, p = 0.017; B: -0.425, 95% CI: -0.833 to -0.017, p = 0.041, respectively). Conclusions: Cognitive decline is significantly associated with a higher risk of AF, with atrial remod- eling being a potential mechanism. Our results extend previous findings of the brain-heart axis and indicate the effects of cognitive injury on cardiac function and structure. (Cardiol J)