Fifth Universal Definition of Myocardial Infarction (2026): On Behalf of the Joint European Society of Cardiology (ESC)/American College of Cardiology (ACC)/American Heart Association (AHA)/World Heart Federation (WHF) Task Force for the Universal Definition of Myocardial Infarction

“People may think of an MI as a heart attack caused by a blocked coronary artery but there are many different causes of MI. The previous universal definition used a numerical system to categorize the different types of MI but this was not always easy to apply in clinical practice, leading to inconsistences in diagnosis and treatment. The ESC, ACC, AHA and WHF have worked together to devise an updated and simplified classification system for MI, which aims to address these limitations.”

L. Kristin NewbyCardiologist, Duke University Medical Center

“The definition incorporates sex-specific cardiac troponin thresholds to avoid systematic bias and underdiagnosis in female patients. The use of imaging is encouraged to define the etiology of MI, and this will support more personalized care, recognizing that treatment differs depending on the underlying cause and setting in which it occurs.”

L. Kristin NewbyCardiologist, Duke University Medical Center

“Clinicians often do not use the previous numerical terminology – e.g. type 2 or type 4c – in patient discussions as it is rather complex. With the new approach, we can now talk with patients about the cause of their MI so that they can understand their condition and recognise why the next steps, such as further tests and treatments, are needed.”