[Clinical implications of the fourth universal definition of myocardial infarction].

This disease with its multiple ischemic and non-ischemic manifestations is classified based on the fourth universal definition of myocardial infarction (MI). An acute myocardial injury is defined as a significant increase of cardiac troponins (cTn). In patients with an additional myocardial ischemia, which is defined by certain clinical, electrocardiographic, imaging and angiographic criteria, the diagnosis of acute MI can be made. Etiologically, MI can be divided into 5 types: type 1 ischemic by plaque rupture or plaque erosion with thrombus formation, type 2 imbalance between myocardial oxygen demand and supply, type 3 MI as suspected cause of death before determination of cTn, type 4a <48 h after percutaneous coronary intervention (PCI), type 4b stent thrombosis, type 4c in-stent stenosis and type 5 <48 h after coronary artery bypass grafting (CABG). This classification reflects the heterogeneity of acute MI. Based on clearly defined criteria the guidelines attempt to provide clinically active physicians with assistance in the diagnosis and treatment of this specific disease. Nevertheless, it is still necessary to take a holistic view of the patient with all the individual characteristics.