Carotid Intima-Media Thickness and Arterial Stiffness and the Risk of Atrial Fibrillation: The Atherosclerosis Risk in Communities (ARIC) Study, Multi-Ethnic Study of Atherosclerosis (MESA), and the Rotterdam Study

Background-We evaluated the association of carotid intima-media thickness (cIMT), carotid plaque, carotid distensibility coefficient (DC), and aortic pulse wave velocity (PWV) with incident atrial fibrillation (AF) and their role in improving AF risk prediction beyond the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE)-AF risk score. Methods and Results-We analyzed data from 3 population-based cohort studies: Atherosclerosis Risk in Communities (ARIC) Study (n= 13 907); Multi-Ethnic Study of Atherosclerosis (MESA; n= 6640), and the Rotterdam Study (RS; n= 5220). We evaluated the association of arterial indices with incident AF and computed the C-statistic, category-based net reclassification improvement (NRI), and relative integrated discrimination improvement (IDI) of incorporating arterial indices into the CHARGE-AF risk score (age, race, height weight, systolic and diastolic blood pressure, antihypertensive medication use, smoking, diabetes, previous myocardial infarction, and previous heart failure). Higher cIMT (meta-analyzed hazard ratio [95% CI] per 1-SD increment, 1.12 [1.08-1.16]) and presence of carotid plaque (1.30 [1.19-1.42]) were associated with higher AF incidence after adjustment for CHARGE-AF risk-score variables. Lower DC and higher PWV were associated with higher AF incidence only after adjustment for the CHARGE-AF risk-score variables excepting height, weight, and systolic and diastolic blood pressure. Addition of cIMT or carotid plaque marginally improved CHARGE-AF score prediction as assessed by the relative IDI (estimates, 0.025-0.051), but not when assessed with the C-statistic and NRI. Conclusions-Higher cIMT, presence of carotid plaque, and greater arterial stiffness are associated with higher AF incidence, indicating that atherosclerosis and arterial stiffness play a role in AF etiopathogenesis. However, arterial indices only modestly improve AF risk prediction.