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. Several of the risk factors for incident AF are also risk factors for stroke in AF.18 Primary prevention strategies for AF have not been conclusively proven in randomized trials, and opportunistic screening is the recommended strategy to detect AF at the population-level.19 A systematic review of the associations of 23 cardiovascular risk factors and incident AF including 20,420,175 participants and 576,602 AF events, respectively, found hypertension, obesity, taller height, and coronary heart disease showed consistent, direct associations with incident AF.18 Ethnic differences in comorbidities in AF patients have been reported Hypertension is the leading comorbid risk factor and is equally distributed in different races. Coronary heart disease seems more common in whites and the Middle East, than in Asians. The annual risk of AF-associated stroke in Asians is higher than that in and the risk of stroke may start to increase at a younger age in Asians.37 Classi cation of AF AF is classi ed as paroxysmal (self-terminating within 7 days), persistent (continuous for > 7 days), long- standing persistent (continuous for > 1 year), or permanent (chronic). AF becomes increasingly persistent and resistant to therapy over time, perhaps due to the development of atrial brosis, as well as other pathophysiological processes (e-Fig 2). 