Heart attacks are increasing in prevalence among people under 40, according to a new study authored by doctors with Brigham and Women’s Hospital in Boston.

The study, which appeared in the Journal of the American College of Cardiology, evaluated patients under 50 that were admitted to two large hospitals following a type 1 heart attack.

Among the total of 2,097 young patients who had a type 1 heart attack, a total of 431 were less than 40 years old.

When compared with patients older than 40, younger patients had greater substance abuse, although the prevalence of other risk factors such as diabetes, hypertension, and smoking were similar, the study said.

The study found that all-cause deaths and cardiovascular deaths in people under 40 following a heart attack has steadily increased in the past decade.

The CDC says there are five signs someone is experiencing a heart attack. If you notice someone experiencing the symptoms of a heart attack, you are urged to call 911 immediately.