The rate of sudden cardiac death in African-Americans is twice as high as in whites, and no one knows why.
Sudden cardiac death is an unexpected fatality from cardiac causes that happens within an hour of the onset of symptoms, usually with no known cause.
For more than six years, researchers followed 9,416 blacks and 13,091 whites who had no history of cardiovascular disease. Over the period, 67 whites and 107 blacks died suddenly with heart symptoms. The study is in the Journal of the American College of Cardiology.
The researchers controlled for education, physical activity, depression, cholesterol and other factors. Blacks tended to have lower incomes, were less likely to be insured and had higher rates of smoking, diabetes and high blood pressure. But even after accounting for these differences, they found that the risk for sudden cardiac death was still 97 percent higher in blacks than in whites.
The lead author, Dr. Rajat Deo, an associate professor of medicine at the University of Pennsylvania Perelman School of Medicine, said that there could be variables they were unable to rule out, or unknown genetic factors that predispose blacks to heart rhythm disorders.
In any case, he said, “Over the last two decades, we’ve seen a reduction in heart attacks and stroke, but we haven’t seen the same kind of reduction in sudden cardiac death. I think more work needs to be done.”