The gap is narrowing, but African Americans who suffer a Heart attackare still getting less aggressive treatment compared with whites, according to a new study.

In an analysis of hospital discharge records in 23 states, researchers found that black patients hospitalized for a Heart attack were 13 percent less likely than white patients to have received an invasive procedure to open up blocked heart arteries.

The data, which covered the years 1995 through 2001, revealed a smaller treatment gap between white and black patients than studies had found in the 1980s and early 90s. However, racial disparities persist, and the reasons are still uncertain, the study authors report in the Journal of the National Medical Association.

“There is still work to be done to understand why this disparity exists,” lead author Dr. Alain G. Bertoni, of Wake Forest University Baptist Medical Center in Winston-Salem, North Carolina, said in a statement.

Differences in illness severity, as well as patient preferences, may help explain the racial gap, according to Bertoni. However, he and his colleagues note in the report, studies have also suggested that doctors refer women and minorities for heart catheterization less often.

Cardiac catheterization involves inserting a thin tube through an artery, usually in the groin, and snaking it up to the arteries supplying the heart. This allows doctors to view the heart and coronary arteries on a screen, and it is often used as a diagnostic procedure.

When a patient has just had a heart attack, however, doctors may also perform Angioplasty  - in which a balloon inserted into a special catheter is inflated in order to push fatty deposits aside and clear a wider path for blood flow. Then, doctors may implant mesh tubes called stents, which help keep diseased blood vessels propped open.

In the current study, patients whose records stated that they had had Angioplasty  or stenting were considered to have had Cardiac catheterization.

Overall, Bertoni’s team found, 58 percent of white patients received catheterization, versus 50 percent of black patients and 55 percent of Hispanic patients.

When the researchers weighed other factors - such as age and co-existing health conditions that could make catheterization risky - black men and women were still 13 percent less likely than white patients to have the procedure.

In contrast, the disparity between Hispanic and white patients was less significant and faded over time - with the rate of catheterization among Latinos nearing that of whites after 1999, according to the report.

Finding out why racial disparities in heart attack treatment persist will be increasingly important as the U.S. population ages and grows more ethnically diverse, Bertoni and his colleagues write.

In their study, differences in insurance coverage and hospital characteristics did not explain the racial gap, nor did measures of overall health - though, the researchers note, they were not able to account for all the health factors that could have swayed decisions on catheterization.

According to Bertoni, increasing African Americans’ awareness of their heart attack treatment options could further close the racial gap.

“If African-American patients are more informed,” he said, “they can have improved dialogue with the medical team deciding how to care for them.”

SOURCE: Journal of the National Medical Association, March 2005.