Blacks Significantly Less Likely to Know They Have Atrial Fibrillation; also Less Likely to Use Warfarin for the Condition

New research from scientists at the Mayo Clinic reveals that African Americans are significantly less likely to know that they have atrial fibrillation, or to use warfarin for treating the condition. These findings could help provide an explanation for why African-Americans are more likely to suffer a stroke and to die from a stroke, according to the researchers.

Between 2003 and 2007, the REGARDS (The Reasons for Geographic and Racial Differences in Stroke) trial enrolled 30,239 men. Among the patients whose ECG revealed atrial fibrillation, 88 of them, or 20%, were black, and 344 were white. However, while 60% of the entire group was aware that they had atrial fibrillation, “the odds that blacks knew they had the condition were less than one-third of those reported for whites.” In addition, “the odds of blacks being treated with warfarin, which reduces stroke risk by 60 percent, were one-fourth those of whites.”

Although the researchers were not sure about the reasons for the disparity, they did note that insurance was likely not a factor, because most of the participants were 65 and older and covered by Medicare. They did note that patients may not have been diagnosed with atrial fibrillation because the condition is often asymptomatic, or that patients who were diagnosed either did not remember it or did not “fully appreciate the significance of the condition.”

The researchers deliberately "oversampled" blacks, which comprised 42% of the study group, as well as residents of the Southeastern "Stroke Belt.” Study participants from North Carolina, South Carolina, Georgia, Alabama, Mississippi, Tennessee, Arkansas, and Louisiana made up 56% of patients.

“These findings should lend urgency to focused efforts to improve patient education and medical treatment across the board," said James Meschia, MD, Mayo Clinic neurologist and director of the Comprehensive Stroke Center at Mayo's campus in Florida. "Whatever the reasons behind these observations, it appears that there is a missed opportunity to prevent stroke and other thromboembolic complications from atrial fibrillation because many individuals may fail to have the condition diagnosed and/or fail to receive treatment with warfarin. It would benefit public health if future research could tease out the reasons behind this disparity."