Fifth UDMI 2026 — Fifth Universal Definition of Myocardial Infarction

Defines myocardial injury using cardiac troponin above the assay-specific 99th percentile and requires a rise/fall for acute injury. Myocardial infarction requires acute myocardial injury plus evidence that the injury is ischemic. MI is classified clinically as primary, secondary, or procedure-related; the document also reframes MINOCA as myocardial injury with non-obstructive coronary arteries requiring etiologic evaluation.