The manuscript was revised according to feedback from the reviewers. Stroke Risk in AF The extensive data on epidemiologic burden of stroke associated with AF and well as the pathophysiology is detailed in e-Appendix 1. It is beyond the scope of this document to consider the epidemiology of all comorbidities in AF. In summary, health-care systems face increasing prevalence, incidence, and lifetime risk of AF, which is as high as 1 in 4 in contemporary studies in high-income Epidemiologic studies largely represent Western countries and white populations.16 However, reported prevalence varies substantially by world region (e-Fig 1) and with more rigorous screening methods to detect AF. Individuals with AF have increased risk of stroke (fourfold to vefold increase), HF (twofold to threefold fold increase), and mortality (twofold increase) (see e-Appendix 1). Patients with AF also experience higher rates of morbidity and hospital admissions, as well as early dementia. The high AF-attributable risk of stroke, especially in the elderly, is evident since at least 1 in 3 to 4 individuals with an ischemic stroke, and > 80% of those with ischemic stroke of cardioembolic subtype, also have Overall, non-white ethnicity shows evidence of association with lower risk of incident AF. 