Women are less likely to get immediately treatment for heart attack and more likely to die than men, according to a new study.

The study, conducted by researchers from the Lakeland Regional Medical Center in Florida, the United States, was published on Tuesday in the Journal of the American Medical Association.

By analyzing data from 1.1 million tracked patients at more than 1,000 hospitals, the researchers found that women have 15 percent chance of dying of a heart attack in the hospital compared to men's 10 percent.

And among the patients, 42 percent women never experienced the classic symptom of heart attack - the chest pain or discomfort. This may be the main reason for women’s treatment delay.

"Women often present with suddenly feeling tired, fatigue, nausea, reduced exercise tolerance, rather vague," said Dr. Ed Fry, cardiologist at St. Vincent Heart Center.

Women's smaller blood vessels compared with men may be one of the reasons of different symptoms, he added.

More researches will be done for trying to identify why there are such variations in the way heart disease affects men and women, researchers said.