# Global myocardial infarction diagnostic guidelines update > Live situation record from CLSTR: https://clstr.news/situations/global-myocardial-infarction-diagnostic-guidelines-update > Updated: 2026-09-01T11:15:30.000Z. Sources: 5. Developments: 2. Major global medical organizations, including the European Society of Cardiology (ESC), the American College of Cardiology (ACC), the American Heart Association (AHA), and the World Heart Federation (WHF), have released the fifth edition of the Universal Definition of Myocardial Infarction. The new guidelines transition from a five-type classification to a simplified framework consisting of three primary categories: primary, secondary, or procedure-related infarctions. This update aims to increase diagnostic precision by focusing on integrated cardiac injury mechanisms rather than isolated symptoms. By expanding the definition of primary myocardial infarction to include various triggers such as plaque rupture, embolisms, or vasospasms, the framework seeks to reduce diagnostic inconsistencies. The update is specifically expected to improve healthcare outcomes for women, who are frequently misdiagnosed due to subtle symptoms like fatigue and nausea. ## Timeline ### 2026-09-01: Heart health groups update myocardial infarction definitions Major heart health groups have updated the definitions of myocardial infarctions to include more triggers, aiming to improve diagnostic accuracy and gender parity in heart attack care. 3 sources. https://clstr.news/cluster/heart-health-groups-update-myocardial-infarction-definitions ### 2026-08-29: Medical societies release new universal myocardial infarction guidelines Major medical societies have released the fifth edition of the Universal Definition of Myocardial Infarction, simplifying heart attack classification into three groups to improve diagnostic accuracy. 2 sources. https://clstr.news/cluster/medical-societies-release-new-universal-myocardial-infarction-guidelines --- Cite as: Global myocardial infarction diagnostic guidelines update. CLSTR, https://clstr.news/situations/global-myocardial-infarction-diagnostic-guidelines-update