LOS ANGELES, May 2 (Xinhua) -- Women aged 55 years and younger have nearly double the risk of rehospitalization in the year immediately after a heart attack compared to men of similar age, according to a study supported by the U.S. National Institutes of Health (NIH).

Higher rates of risk factors such as obesity, heart failure, and depression among women most likely contributed to the disparity, according to the study published Tuesday in the Journal of the American College of Cardiology.

The findings suggest a need for closer health monitoring of the approximately 40,000 American women aged 18 to 55 years who have heart attacks each year following hospital discharge, and a better understanding of the reasons behind the different outcomes, said the NIH.

"We have shown for the first time that rehospitalizations following heart attacks in women aged 55 and younger are accompanied by certain non-cardiac factors, such as depression and low-income, that appear more common in women than men and are associated with more adverse outcomes," said corresponding author Harlan M. Krumholz, a cardiologist and professor of medicine at the Yale School of Medicine.