Abstract
BACKGROUND: Within the United States, White individuals experience a higher risk of atrial fibrillation (AF) while exhibiting a lower AF-related stroke risk compared to other ethnic groups. It is possible that these observations stem from phenomena unique to the United States, such as differential health care access. The United Kingdom provides socialized medicine, which ostensibly promotes equitable health care access. OBJECTIVES: The purpose of the study was to examine whether ethnic differences in the risks of AF and AF-related stroke and systemic infarcts exist in the United Kingdom. METHODS: We leveraged longitudinal data from the UK Biobank between January 1, 2006, and June 30, 2020. Ethnicity was categorized as White, Black, South Asian, Chinese, or multiracial. Incident AF, stroke, and systemic infarct were ascertained from in- and out-patient records. RESULTS: A total of 458,785 participants (438,333 White, 7,244 Black, 9,143 South Asian, 1,376 Chinese, and 2,689 multiracial) were included. After excluding those with prevalent AF, 8,706 developed incident AF. Black individuals (HR: 0.60; 95% CI: 0.49-0.74; P < 0.001), South Asians (HR: 0.59; 95% CI: 0.49-0.72; P < 0.001), and Chinese (HR: 0.31; 95% CI: 0.12-0.83; P = 0.002) each exhibited substantially lower risks of AF compared to White individuals after multivariable adjustment. In AF participants, incident stroke and systemic infarct occurred in 1,550. No significant differences in the risk of AF-related stroke and systemic infarcts by ethnicity were detected, but small numbers of these events were present. CONCLUSIONS: In a European population with universal access to health care, White individuals consistently experienced the highest risk of AF, but there were no detectable differences in AF-related stroke or systemic infarcts.