Even when they have the same amount of plaque clogging their coronary arteries, men and women face different health risks, a new study suggests.

Researchers at the Medical University of South Carolina found that women faced a significantly higher risk of major cardiac events due to plaque buildup and hardening of the arteries. Men, however, had higher risks when "non-calcified" plaque built up in their arteries.

"This is so intriguing because now we’re really starting to figure out the gender differences in heart disease," said Dr. Suzanne Steinbaum of Lenox Hill Hospital in New York, who was not involved in the study. "We've known in the past that women tend to deposit plaque differently."

The study was based on records of 480 patients with acute chest pain, two thirds of whom were women about 55 years old on average. The findings were to be presented this week at the meeting of the Radiological Society of North America.

"We’re not sure why the risk differences exist, but women have smaller blood vessels and men have larger," said Dr. Jennifer Mieres, a cardiologist with the North Shore-LIJ Health System in Manhasset, N.Y.