A new clinical classification of acute myocardial infarction

The existence of a universal definition of myocardial infarction – which involves classification into multiple subtypes – has promoted the use of standard diagnostic criteria across the world. However, this classification has not been applied consistently in practice and is perceived by some as too complicated. Where there is diagnostic uncertainty, patients have worse outcomes. This uncertainty has also impacted on the validity of the diagnosis of myocardial infarction in clinical trials. To address these issues and to encourage clinicians to recognise that different mechanisms of myocardial infarction have differing treatment implications, we propose an alternative clinical classification for consideration; one that recognises that myocardial infarction can arise spontaneously, secondary to another condition, or as a complication of a cardiac procedure. This classification is aligned with clinical practice and proposes more objective and specific diagnostic criteria that, if agreed by international consensus, could reduce diagnostic uncertainty in practice and research.