This so-called "non-calcified plaque" -- which consists of soft deposits that accumulate deep in the walls of arteries -- can rupture and send out blood clots that can lead to heart attacks.
The new study looks specifically at non-calcified plaque, not calcified plaque, which is commonly monitored in coronary screening tests. The study authors said ordinary calcium screening tests such as CT scans may not be as valid for blacks since they miss the non-calcified plaque.
"For a long time, physicians have searched for explanations as to why African Americans have higher rates of heart disease and higher cardiac death rates, but less coronary artery calcium than Caucasians," said study co-author Dr. U. Joseph Schoepf, professor of radiology and medicine and director of cardiovascular imaging at the Medical University of South Carolina in Charleston, in a news release. "We show that one possible explanation for the discrepancy may be found in the higher rate of less stable, non-calcified plaque in the heart vessels of African Americans."
