The researchers followed 936 healthy women enrolled in the National Institute of Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation. After five years, all of the women who earned more than $100,000 a year were still alive and free of heart disease, compared with just 78% of those earning less than $20,000 annually.
The study, which was designed to find out which socioeconomic factors have the greatest impact on heart health, showed that insurance status was the second most important socioeconomic factor affecting survival.
Whether a woman had a full-time job also affected her risk of deadly heart conditions, but surprisingly, race did not, says researcher Leslee Shaw, PhD, associate professor of medicine at UCLA.
Overall, a woman's socioeconomic status was the second largest risk factor for dying, trailing only pre-existing heart disease, she says.
"The nail of the matter," Shaw tells WebMD, "is that it is not being nonwhite that is the challenge, but being poor."
Many studies have shown that blacks, Asians, Hispanics, and American Indians are at higher risk of dying of heart disease than whites, she notes.
Many Elderly Women at Risk
More women than one might think fall into low-income categories that place them at an increased risk of dying from heart disease, says Shaw.
"If you look at census data, the median income of 65-year-old women is only $14,000 a year," she says. "That means more than half of elderly women, regardless of race, may be at increased risk."
Lower-income women also tend to have more symptoms, yet be on fewer medications, than their wealthier counterparts, she says.
Yet in the end, more money may end up being spent on poorer women, as they are more likely to be hospitalized at an earlier stage of illness, Shaw says.
Augustus Grant, MD, PhD, a past president of the American Heart Association and professor of medicine at Duke University Medical Center in Durham, N.C., says the study points to an important gap in care.
"We need to look at health care delivery at the societal level and ensure equal access for all," he tells WebMD.
The study was presented at the annual meeting of the American Heart Association.