American College of Cardiology (ACC)

Rule Changes

As of September 2026: Co-developer of the Fifth Universal Definition

For decades, the blood test for heart attacks used a single threshold for every patient. That threshold caught nearly all men having heart attacks but missed some women, because women naturally carry lower levels of the heart-injury protein troponin. The world's four leading cardiovascular organizations just agreed on the first universal definition of a heart attack, and it corrects that bias.

Updated Sep 10