First-Ever International Classification of Four Stages of Heart Attack Based on Heart Muscle Damage (CCS-AMI) Released

OTTAWA, October 30, 2023 – On October 28, 2023, the Canadian Cardiovascular Society Classification of Acute Myocardial Infarction (CCS-AMI) – a new, never-before released classification of four stages of heart attack – was published in the Canadian Journal of Cardiology. A presentation at the Vascular 2023 conference in Montréal followed on October 29.

This is the first heart attack classification of its kind to be released within Canada and internationally. The classification will help physicians and cardiac health care providers better estimate and predict a patient’s risk of developing heart failure, arrhythmia, or dying. It will also open new avenues of research for more precise and individualized therapies to address the underlying damage at each heart attack stage.

What is acute myocardial infarction (MI)?
An acute myocardial infarction is also known as a heart attack. A heart attack occurs when blood flow to the heart muscle decreases or stops, and the heart muscle begins to die because it isn’t receiving enough oxygen. A heart attack is a medical emergency that requires immediate intervention from a healthcare provider to prevent permanent heart damage and death.

How are MIs categorized currently?
Existing tools classify MIs using a patient’s clinical presentation and/or the cause of the heart attack, as well as ECG findings. Although these tools are very helpful to guide treatment, they do not consider the underlying tissue damage caused by the heart attack.

What is the CCS Classification of Acute Myocardial Infarction (CCS-AMI)?
The CCS-AMI Classification describes damage to the heart muscle following an MI in four sequential and progressively severe stages. It is based on a strong body of evidence about the effect an MI has on the heart muscle.

What are the four CCS-AMI stages?
The four CCS-AMI stages are:

  • CCS Stage 1 – No or minimal damage to the heart muscle.
  • CCS Stage 2 – Damage to the heart muscle and no injury to small blood vessels in the heart.
  • CCS Stage 3 – Damage to the heart muscle and blockage of small blood vessels in the heart.
  • CCS Stage 4 – Damage to the heart muscle, blockage and rupture of small blood vessels resulting in bleeding into the heart muscle.

As damage to the heart increases through each progressive CCS-AMI stage, patients have dramatically increased risk of complications such as arrhythmia, heart failure and death with each stage. Appropriate therapy can potentially stop injury from progressing and halt the damage at an earlier stage.

How do cardiovascular doctors determine the CCS-AMI stage?
Cardiovascular doctors use a patient’s test results to determine the CCS-AMI stage. Tests may include blood work, electrocardiogram (ECG), angiography, echocardiogram, and/or cardiac magnetic resonance imaging (CMR).

Who is leading this work?
The CCS-AMI is an expert consensus statement. Drs Andreas Kumar (Cardiologist, Associate Professor of Medicine, NOSM University, Canada) and Rohan Dharmakumar (Executive Director and Charles Fisch Professor of Cardiology, Krannert Cardiovascular Research Center of Indiana University, USA) initially developed the classification. Then, the Canadian Cardiovascular Society (CCS) formed an expert writing group to review and refine it. CCS has also established a working group to allow for ongoing clinical and scientific refinement of the CCS-AMI.

How will patients benefit from the CCS-AMI?
Currently, heart attack patients are all treated similarly according to existing medical guidelines. However, not all heart attacks are the same. The new classification will help differentiate heart attacks according to the stage of damage and allow health care providers to more precisely estimate a patient’s risk for arrhythmia, heart failure, and death. The classification provides a framework for the development of precision therapies that will take the specific stage of tissue damage into account.

This is ultimately expected to lead to better care, better recovery, and better survival rates for heart attack patients.

Media Contact
Stephanie Naday
Director of Communications
Canadian Cardiovascular Society
(403) 828-1017

About the Canadian Cardiovascular Society
The CCS is the national voice for cardiovascular clinicians and scientists, representing more than 2,300 cardiologists, cardiac surgeons and other heart health specialists across Canada. We advance heart health for all by setting standards for excellence in heart health and care, building the knowledge and expertise of the heart team, and influencing policy and advocating for the heart health of all Canadians. For further information on the CCS visit: