Heckbert SR, Austin TR, Jensen PN, et al. - Researchers conducted a cross-sectional analysis in the MESA (Multi-Ethnic Study of Atherosclerosis) to investigate the differences by race/ethnicity in the prevalence of clinically detected atrial fibrillation (AF) and in the proportion with monitor-detected AF. Enrollment of 6,814 Americans who were free of clinically recognized cardiovascular disease was done in MESA from 2000 to 2002. At the 2016 to 2018 examination, they performed an ancillary study including 1,556 individuals (51% women; the mean age: 74 years) who underwent ambulatory ECG monitoring and had follow-up for clinically detected AF since cohort entry. Among 1,556 participants, 41% were white, 25% African American, 21% Hispanic, and 14% Chinese. After 14.4 years of follow-up, clinically identified AF was prevalent in 11.3% among whites, 6.6% in African Americans, 7.8% in Hispanics, and 9.9% in Chinese. African Americans exhibited significantly lower prevalence than whites, in both unadjusted and risk factor-adjusted analyses. By contrast, in the same individuals, the proportion with monitor-detected AF utilizing a 14-day ambulatory ECG monitor was comparable in the 4 race/ethnic groups: 7.1%, 6.4%, 6.9%, and 5.2%, respectively (compared with whites). Findings thereby render support for the hypothesis of differential disclosure by race/ethnicity in the clinical identification of AF, which may have significant indications for stroke prevention.