New Universal Definition of Myocardial Infarction

Abstract

Recently, a joint ESC/ACCF/AHA/WHF Task Force published an expert consensus document on the universal definition of myocardial infarction [1]. The following points are extracts from this document that summarize its main features. The main reason for agreeing on a new definition of myocardial infarction derives from the development and the wide availability of very sensitive and specific serological biomarkers that are able to detect even minimal myocardial necrosis. Acute myocardial infarction is diagnosed when there is evidence of myocardial cell necrosis in the clinical setting of myocardial ischemia. In contrast to the historical World Health Organization (WHO) definition where symptoms, ECG and enzymes had equal weight for the diagnosis (the presence of any two would suffice), today biomarkers take precedence with imaging having also a diagnostic role. Consequently, acute myocardial infarction is diagnosed if a rise and fall of cardiac biomarkers (preferably troponin) is detected together with at least one of the following: a) symptoms of ischemia, b) new ST-T changes or new left bundle branch block (LBBB), c) development of pathological Q waves and d) imaging evidence of new loss of viable myocardium or new regional wall motion abnormality.Prior myocardial infarction requires for its diagnosis any of the following criteria: a) new Q waves, b) imaging of a regional loss of viable myocardium that is thinned and fails to contract and c) pathological findings of a healed or healing myocardium.