Aspirin may significantly reduce death rates in post-menopausal women with heart disease, according to a long-term observational study reported by researchers on Monday.

“It was shown before and we have shown it again: Aspirin is a life-saving therapy,” said Dr. Jeffery Berger, the study’s lead author.

“Women with cardiovascular disease should be on aspirin” unless there is some medical reason that they cannot tolerate the common, over-the-counter medicine, Berger said.

The study, presented at the American Heart Association scientific sessions, included 8,928 women with heart disease between the ages of 50 and 79, 46 percent of whom were taking either 81 milligrams or 325 mg of aspirin per day.

During six and a half years of follow-up observation, the women taking aspirin had a 17 percent reduction in death from all causes and a 25 percent lower death rate from heart disease, researchers said.

Because it was not a randomized trial, researchers said they could not definitively conclude that aspirin caused the reduction in death rates.

However, Berger said the reduction in death rate was the same in women taking either dose of aspirin. He called for more aspirin dosing studies in women as higher doses are associated with increased risk of side effects, such as gastric bleeding.

“Unfortunately, when you look at the aspirin data, you find that women have been underrepresented in many of the studies,” Berger said.

“There is no conclusive data that provides the optimal dose or effect of aspirin usage in women, but it does appear that 81 mg is as effective as 325 mg,” he said.

He said the findings reported on Monday may not apply to young women with heart disease because only post-menopausal women participated in the study.