A new study shows women who suffer heart attacks are more likely to die before leaving the hospital than men admitted with the same condition.

The study involved 4,315 men and 1,524 women who had had heart attacks, and found that 23 percent of the women and 16 percent of the men died during their initial hospital stay.Heart attacks, the leading killer of American women, tend to strike females when they are older and have more health problems, said Dr. Phillip Greenland, whose study appears in the February issue of the Dallas-based American Heart Association journal "Circulation."

After researchers made adjustments for the ages of men and women studied, they found no significant differences in death rates when comparing heart rhythm and whether the patients had previous heart attacks.

But women with diabetes tended to have a greater chance of dying than men who also had diabetes, said Greenland, an associate professor of medicine at the University of Rochester School of Medicine in New York.

"We understand that diabetes can lead to changes in the heart muscles, but what's very peculiar is why this can lead to such difference in women as opposed to men," he said.

The women in Greenland's study also had a higher incidence of heart failure than the men.

"We know that heart failure at the time of heart attack is usually a consequence of cumulative heart damage," Greenland said.

Evidence suggests women and diabetics are more prone to "silent ischemia," a recently discovered condition in which part of the heart muscle starves for blood and yet doesn't cause pain.

"One theory is that the women with heart failure had had previous heart attacks without feeling them," Greenland said.

Greenland spent last year at Tel Aviv University analyzing data compiled by Israeli researchers who studied more than 5,800 heart attack patients hospitalized between 1981 and 1983.

He said the study is more significant than previous efforts - which produced contradictory conclusions - because a larger statistical sampling was used.

Critics have said government-funded research typically focuses too heavily on middle-aged white men, overlooking knowledge about women's health.