We expect doctors to follow established clinical guidelines, which are sets of recommendations culled from the findings of medical research. But in reality, they don’t always do so. However, a new study shows that patients do better when doctors follow clinical guidelines when caring for them.

The study, published in the Journal of the American Medical Association, looked at patients in Sweden who were treated for a particularly damaging type of heart attack between 1996 and 2007. During the 12 years of the study, treatments proven to help heart attack patients, including drugs to break up blood clots and procedures to open arteries, became more common.

Patients whose doctors implemented the new procedures did better, the study found.

In fact, their risk of dying in the year following their heart attack dropped from 21 percent to just 13 percent.