A new study presented at the American Heart Association annual meeting suggests people who use cocaine may have stiffer arteries, higher blood pressure and thicker heart muscles, all of which can lead to a heart attack.

“It’s so sad,” lead researcher Gemma Figtree of the University of Sydney in Australia said in a news release. “We are repeatedly seeing young, otherwise fit individuals suffering massive heart attacks related to cocaine use. Despite being well-educated professionals, they have no knowledge of the health consequences of regularly using cocaine.”

The researchers used MRI scans to study the hearts of 40 healthy adults, CBS News reports. They also measured participants’ blood pressure. Half of the study subjects admitted to using cocaine at least once a month in the past year, while the other half did not use cocaine.

Cocaine users had more stiffening of the arteries, higher blood pressure and greater thickness in their heart’s left ventricle wall, compared with non-users. The study did not examine the rate of heart attacks among people who used cocaine.

The researchers said their study is the first to document some of these heart abnormalities in seemingly healthy cocaine users long after the immediate effects of the drug have worn off.