Reasons for the fourth definition of myocardial infarction

Dr P.J. Devereaux is a professor in the Department of Health Research Methods, Evidence, and Impact and Department of Medicine and director of the Division of Cardiology at McMaster University.

Why was the new definition of myocardial infarction (MI) necessary? What have we learned about MI since the third definition?

P.J. Devereaux, MD, PhD: I think there are some important distinctions around clearly defining myocardial injury and making distinction between myocardial injury and MI, or important new aspects of the fourth universal definition of MI. Also, there has been further knowledge from things like cardiac magnetic resonance imaging (MRI) and its use within defining MI.

There has been progress in a number of areas. I think that probably the most important distinctions are related to the issue of [differentiating between] myocardial injury and MI.