Pocket Guidelines on the Fifth Universal Definition of Myocardial Infarction

Publication Date:  August 2026
Chairpersons: Nicholas L. Mills, L. Kristin Newby and Sarah Zaman

Table of Contents

Introduction

Executive summary

Context

Objective 

What is new 

Definition of myocardial infarction

Acute and chronic myocardial injury

• Acute myocardial injury
• Chronic myocardial injury

Classification of myocardial infarction

• Clinical classification of myocardial infarction
  • Primary myocardial infarction
  • Secondary myocardial infarction
  • Procedure-related myocardial infarction

Diagnosis of myocardial infarction following sudden death

Silent or unrecognized myocardial infarction

Myocardial injury with non-obstructive coronary arteries

Symptoms of myocardial infarction

The electrocardiogram

Cardiac biomarkers

• Cardiac troponin
  • Defining the 99th percentile upper reference limit
  • Serial measurements
  • Defining a significant rise and fall
  • Accelerated diagnostic pathways
  • Interpretation of cardiac troponin for diagnosis

Coronary and cardiac imaging

• Invasive imaging
• Invasive coronary angiography
• Intravascular imaging
• Invasive functional testing

Non-invasive imaging

• Echocardiography
• Cardiac magnetic resonance imaging
• Coronary computed tomography angiography

Special situations

• Recurrent myocardial infarction
• Heart failure
• Chronic kidney disease
• Critical illness
• Non-cardiac surgery
• Structural cardiac intervention
• Cardio-oncology

Implications for patients, secondary prevention, and cardiac rehabilitation

Implications for public health and classification of disease

Implications and adaptions for low-resource settings

Implications of the definition on research