Women who face financial struggles double their risk of heart attacks, according to new research from the American Heart Association. Stress has long been known to contribute to the risk of heart disease and heart attack, but the new study looked at the effects of specific types of stress on women's heart health.

They found that while the death of a spouse, a life-threatening illness, or the death of a child increased the chances of a heart attack by more than 65 percent among women who were middle-aged and older, financial struggles increased the risk two-fold.

"Much of the prior research related to negative life events was done in persons who have a history of heart attacks and in men," said Michelle A. Albert, M.D., M.P.H., senior study author and director of the CeNter for the StUdy of AdveRsiTy and CardiovascUlaR DisEase (NURTURE Center) at the University of California Medical Center, San Francisco.

"It is important to assess these relationships in middle-aged and older women as this age group is more susceptible to heart disease as they age and are likely to live longer with disability."

The study was based on answers from 26,763 women who participated in the national Women's Health Study. They were asked questions about negative events that had occurred during the previous five years, such as being fired from a job, financial strain, legal problems, an unfaithful spouse, a life-threatening illness, or death of a loved one.

Three of those events — life-threatening illness, death of a loved one, and financial strain — were classified as traumatic. The women were then followed for an average of nine years.

Financial problems were found to be an even bigger risk to heart health than the death of a loved one or a life-threatening illness. Women whose households made less than $50,000 a year, which is above the federal poverty level, were more vulnerable.

"We don’t know whether women are more physiologically vulnerable as some prior research suggests that decreases in blood flow to the heart caused by acute mentally-induced stress is more common in women and individuals with less social support," Albert said.

"At the biological level, we know that adverse experiences including psychological ones can lead to increased inflammation and cortisol levels," she said. "However, the interplay between gender, heart disease and psychological factors is poorly understood."

Heart disease is the No. 1 cause of death among American women.