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

Area of Science:

• Cardiology
• Biomedical Science

Background:

• Acute myocardial infarction (MI) presents with diverse ischemic and non-ischemic manifestations.
• The fourth universal definition of MI provides a framework for classification.

Purpose of the Study:

• To outline the classification of acute myocardial infarction (MI) based on the fourth universal definition.
• To detail the diagnostic criteria for acute myocardial injury and MI.
• To describe the five etiological types of MI.

Main Methods:

• Classification based on the fourth universal definition of myocardial infarction (MI).
• Definition of acute myocardial injury using cardiac troponin (cTn) levels.
• Diagnosis of acute MI incorporating clinical, electrocardiographic, imaging, and angiographic criteria.
• Categorization of MI into five etiological types (Type 1-5).

Main Results:

• Acute myocardial injury is defined by a significant increase in cardiac troponins (cTn).
• Acute MI diagnosis requires evidence of myocardial ischemia alongside myocardial injury.
• Five etiological types of MI are identified: Type 1 (spontaneous), Type 2 (demand/supply imbalance), Type 3 (death before cTn), Type 4a (PCI-related), 4b (stent thrombosis), 4c (in-stent stenosis), and Type 5 (CABG-related).

Conclusions:

• The classification highlights the heterogeneity of acute MI.
• Guidelines aim to assist physicians in diagnosing and treating acute MI.
• A holistic patient view remains essential despite defined criteria.