Time to Tweak the Definition of Type 2 Myocardial Infarction

The Universal definition (UD) of Myocardial Infarction (MI) has been an important contribution to the literature and has, among other aims, helped explain the significance of elevated troponin levels. The clinician caring for patients admitted to the hospital must determine the etiology of the troponin elevation and whether or not it meets criteria for acute MI. The concept of a Type 2 MI- an MI due to a supply/demand mismatch and not to athero thrombosis is one of the most important contributions of the UD. However, its incidence varies widely in the literature likely related to its non-specific diagnostic criteria that are open to subjective interpretation. In this article, the reasons for this lack of specificity are discussed and suggestions made to reduce variability. In conclusion, while the concept of a Type 2 MI is important in the era of sensitive troponin assays, improving Type 2 diagnostic specificity should allow for less subjectivity and greater reproducibility.