MILWAUKEE, April 27 (UPI) -- A study released Thursday shows African-American males have fewer and less severe coronary obstructions than white males.
Although black men are more likely to die from cardiovascular disease, researchers recently came across the incongruous finding that they have fewer cases of coronary obstruction than their "clinically similar" white counterparts.
In the study by researchers at the Medical College of Wisconsin, data were reviewed on 311 African-American and white veterans who had a coronary angiography -- or stress test -- following a positive nuclear perfusion imaging study.
Before this test to assess artery blockage -- a prime predictor of coronary artery disease -- the patient's physician was asked to estimate the probability of coronary obstruction, which was similar; 83 percent for the white patients and 79.5 percent for the African Americans.
But the white men had more severe coronary obstructions, researchers discovered.
"Our findings suggest the need for greater understanding of factors influencing coronary events in diverse populations," said Jeffrey Whittle, associate professor of medicine at the Medical College of Wisconsin in Milwaukee and lead author of the study. "Overall, I believe that as we better understand the mechanism of disease, we'll see that different factors are important for different individuals," he said.
However, the results only raise more questions about heart health among ethnic groups, the researchers noted.
"They're paradoxical. If African-American men have less severe obstructions, why are they dying more frequently? Are nuclear imaging studies less accurate among African-American patients? Were there clinical risk factors that we did not measure? Perhaps African-Americans are less likely to have the kind of coronary obstructions that are suitable for revascularization," Whittle said.
He pointed out that heart attacks don't usually happen as the result of the severe obstructions seen in the study and are caused instead by sudden clot formation.
But this fact might help explain the puzzling results of the study. "Different individuals may differ in their propensity for developing severe obstruction and also differ in their tendency to develop sudden clots," the researchers said.
The study appears in the May 16 issue of the Journal of the American College of Cardiology.
