Women, members of minorities and the very elderly are less likely to receive the most effective care, researchers determined after surveying almost 400,000 heart attack patients 65 and older.

Many heart attack patients are taken to community hospitals that are not equipped to perform the bypass and angioplasty procedures that are the standard of care in heart attacks.

But race, age and sex play important roles in who is transferred to hospitals where those procedures are possible, according to findings presented this month at a meeting of the American College of Cardiology.

Researchers examining Medicare and Medicaid statistics found that compared with Caucasians, African-Americans were 69 percent as likely to be transferred. Hispanics were 53 percent as likely.

Compared with men, women were 84 percent as likely to be transferred, and compared with people ages 65 to 69, those 85 to 90 were only 25 percent as likely to be moved to another hospital.

Dr. Jeffrey S. Berger, the lead author of the study and a cardiology fellow at Duke, said the reasons for the treatment variations were complex and poorly understood.

"Unfortunately," he said, "we still find disparities in the ways patients are handled once they come in with acute heart attacks, so that women and minorities are less likely to be transferred."

"We can't conclusively state that racism is a cause here," Dr. Berger continued. "What we can say is that these disparities exist and that when they affect medical care, we have to do something about them. We have to confront the issue and find out where the problem lies."