Public Release: 

Wide racial disparities found in heart device implantation

Duke University Medical Center

DURHAM, N.C. - African-Americans are significantly less likely than white Americans to receive expensive high-tech implantable defibrillators into the chest to keep their hearts beating regularly, according to a new analysis by cardiologists at Duke University Medical Center.

While the exact reasons for this marked disparity are unclear, the researchers believe that the major barrier facing African-Americans is a lack of access to the latest in appropriate care. Less important factors are patient preferences against invasive procedures and physician bias, they said.

At issue are implantable cardioverter-defibrillators (ICD), devices the size of a deck of cards that are surgically implanted under the skin of the chest, with wires attached to the heart. Whenever the ICD senses that the heart is either beating too fast or too slow, it delivers an appropriate electric impulse to bring the heart back into proper rhythm. ICDs have been proven effective in reducing sudden cardiac death in patients who have already suffered heart attacks.

"As the technology for cardiac devices improves, it is imperative that all patients have equal access to these innovative and life-saving therapies," said DCRI cardiology fellow Kevin Thomas, M.D., who reported the results of his analysis Nov. 15, 2005, at the annual scientific sessions of the American Heart Association in Dallas. "These findings are in line with other studies that have found racial disparities when it comes to other procedures for cardiovascular disease, including coronary artery bypass surgery and angioplasty."

Recent trials have demonstrated the ability of ICDs to prevent sudden cardiac deaths in patients who have already suffered from a heart attack. The ICDs also help those whose hearts have significantly impaired pumping ability, a situation that often leads to heart failure. Compared to other racial groups, African-Americans with heart failure suffer the highest rates of sudden cardiac death..

To determine whether there were any racial disparities in ICD implantation, Thomas consulted the National Registry to Advance Heart Health (ADVANCENT), which collects detailed clinical data on these heart failure patients receiving care at more than 100 centers in the U.S. He identified 6,453 patients who met sudden cardiac death primary prevention criteria for device implantation.

Of those 6,453 patients, 477 were African-American and 5,976 were white. About 37 percent of African-Americans received an ICD, compared to 46 percent for whites.

"In our analysis, even after adjusting for the differences between African-Americans and whites in clinical characteristics and socioeconomic factors, white patients still had a significantly higher likelihood of receiving an ICD," Thomas said.

Thomas believes that a lack of access to the health care system is the main reason why African-Americans do not receive the latest cardiac technologies at the same rates as whites. While this lack of access is due to such factors as lack of insurance coverage, transportation and available health care, there are other access issues at work, he said.

"Many African-Americans live in either urban or rural areas, where it is difficult to find cardiologists, much less those with special electrophysiology training," Thomas said. "Also, we know that many African-Americans with cardiovascular disease are not being cared for by cardiologists so there may be a lack of knowledge about ICDs and their possible benefits. Furthermore, African Americans relative to white Americans are less likely to be cared for at hospitals that perform at the highest levels of national quality of care indicators. These issues must be addressed."

Thomas pointed out that about 90 percent of the patients included in his study were treated by cardiologists, which leads him to believe that the rates of ICD implantation are even lower in the U.S. as a whole.

To a lesser extent, Thomas believes that there may be some physician bias against African-Americans, whether intentional or not. Also, Thomas said that in general African-Americans have an historical mistrust of the medical system, and they may not be willing to undergo an invasive procedure.

"A big part of that mistrust is communication," Thomas said. "If the African-American patient doesn't have a complete understanding of the procedure, or it is not explained well, they may decline the procedure. If an African-American physician or a culturally sensitive health care provider explained the procedure and what it entailed, more African-American patients might agree."

Thomas found it quite telling that African-Americans and whites were prescribed evidence-based medicines such as aspirin, beta-blockers, ACE inhibitors and anti-arrhythmic drugs at the same rates, but not when it came to the high-tech expensive ICD therapy.

Equipped with the knowledge of such disparities proven by this and other studies, Thomas said that future studies need to address specific strategies for solving the problem. For example, he suggested that educational videos be produced with the same information but introduced by people of different races.

"We need to continue to push education and awareness that these racial disparities are real, and to get more people interested in doing something about it," Thomas continued.


The ADVANCENT registry is supported by Guidant Corp., one of the manufacturers of ICDs. Thomas has no financial interests in Guidant. His analysis was supported by the Duke Clinical Research Institute.

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