Updated

The good news: Younger women's survival after heart attack has improved substantially over the past decade, according to a new report in the Archives of Internal Medicine.

The not-so-good news: Women younger than 55 are still less likely to survive a heart attack than their male counterparts, Dr. Viola Vaccarino of Emory University in Atlanta and her colleagues found. And another study in the same journal found heart attacks are becoming more common among women 35 to 54 years old.

Vaccarino and her team first reported a major gender difference in heart attack survival in people under 60 in 1999, a finding other investigators have since confirmed. To investigate whether things might have gotten better, they looked at a registry of more than 900,000 people hospitalized for a heart attack from 1994 to 2006.

Survival improved for all patients, especially women younger than 55. About five percent of women younger than that age died of a heart attack in 1994, compared to 2.4 percent in 2006. The corresponding decline for men under 55 - who saw the smallest improvement - was 2.7 percent to 1.8 percent.

Younger female heart attack patients in 2006 were in better health than they were in 1994, which accounted for most of the difference in death rates, Vaccarino and her team say.

While the current study didn't investigate why, greater awareness among doctors, as well as among women themselves, is like a major factor, the researcher noted in an interview. "Overall we think this is a promising finding," Vaccarino told Reuters Health.

In the other study, Dr. Amytis Towfighi of the University of Southern California, Los Angeles and her colleagues examined national survey data for 1988 to 1994 and 1999 to 2004. Among men, 2.5 percent reported that a doctor told them that that they'd had a heart attack in 1998-1994, compared to 2.2 percent of men in 1999-2004.

For women, the percentage who reported heart attacks increased from 0.7 percent to 1 percent during that same time period.

Obesity and diabetes had become more common over the period studied for both men and women, Towfighi noted in an interview. But while control of risk factors like high systolic blood pressure, smoking and low HDL or "good" cholesterol had all improved for men, women only saw improvements in their HDL cholesterol.

"Men have their risk factors checked more often, they're more likely to be put on medications, and they're more likely to have their risk factors controlled once they are on the medication," Towfighi told Reuters Health.

While the two studies might seem to contradict one another, Vaccarino pointed out that women who would have died after a heart attack in the past are now surviving.

And both researchers agree that the findings underscore the importance of women having regular checkups to watch for risk factors like high blood pressure and high cholesterol, and to get these risk factors under control.

The findings of both studies "are encouraging and indicate that we are on the right track," Drs. Sabine Oertelt-Prigione and Vera Regitz-Zagrosek of the Institute of Gender in Medicine and Center for Cardiovascular Research in Berlin note in an accompanying editorial.

"As these studies show, increased and continuous vigorous attention to the prevention of cardiovascular risk factors-by healthy diet, regular physical activity, and avoidance of smoke and smoking-is necessary for both men and women," they conclude.