It's been a frustrating discrepancy in health for more than a decade: Young women who suffer heart attacks and go to the hospital for treatment have been twice as likely to die as young men. Now, that gender gap is narrowing.

Women under 55 are about 30 percent more likely to die in the hospital after having a heart attack than their male peers, according to research presented yesterday at the American Heart Association conference in New Orleans.

Between 2005 and 2006, 2.4 percent of women under 55 died, a drop from the 5.1 percent who died in 1994 to 1995. Between 2004 and 2006, 1.8 percent of men younger than 55 died in the hospital after experiencing heart attacks, compared with 2.7 percent in 1994 to 1995.

"What we can see is a favorable trend," says Viola Vaccarino, a professor of medicine at Emory University School of Medicine who analyzed 916,380 heart attack patients over 12 years from the National Registry of Myocardial Infarction, a database of treatment information on some of the country's cardiac patients. "The excess mortality we noted early on is narrowing now, which is overall a good sign."

About 1.1 million  people in the U.S. suffer heart attacks annually, and half of them die, according to the National Heart Lung and Blood Institute. Possible gender gaps in mortality for those who suffer heart attacks and don't go to the hospital are tougher to pin down, Vaccarino says.

The reasons for the change aren't entirely clear. One possible factor may be that women's risk factors for heart attacks, such as diabetes, high cholesterol and blood pressure, aren’t worsening as much as men's are, Vaccarino says.

Still, the gap hasn’t disappeared. Studies have noted that young women whose heart attack symptoms are atypical are more likely to be misdiagnosed than are men, and that older African American women are less likely to get reperfusion therapy that restores blood flow to the heart than men are. The use of those therapies in women didn't change much between the mid-90s and 2006, Vaccarino says.

"Because there is more attention to heart disease in women, patients as well as physicians may be more aware of this and doing a better job of alerting women of their risk. Women may be willing to go to the hospital sooner," she says. "But there is still excess mortality, so it's not completely gone, but it's much better than before."

Image by iStockphoto/Marcela Barsse