The Canadian Cardiovascular Society welcomes the Fifth Universal Definition of Myocardial Infarction 

OTTAWA, ON — [September 2, 2026] — The Canadian Cardiovascular Society (CCS) welcomes the presentation of the Fifth Universal Definition of Myocardial Infarction (UDMI) at European Society of Cardiology (ESC) Congress 2026, which recognizes and adopts the Canadian-developed CCS Classification of Acute Myocardial Infarction (CCS-AMI).  

The CCS-AMI classification described for the first time acute myocardial infarction, commonly known as heart attack, as a disease presenting with four sequential stages of increasing tissue injury. By incorporating this CCS tissue-injury framework into the UDMI, the global cardiovascular community including the American Heart Association, American College of Cardiology, European Society of Cardiology, and World Heart Federation are taking an important step toward a more refined, more precise, and more clinically meaningful understanding of heart attacks. 

“This is an important moment for cardiovascular medicine and a proud moment for Canada”, says cardiologist Dr. Andreas Kumar from Northern Ontario School of Medicine University, lead author of the CCS-AMI classification. “Our CCS-AMI classification showed that not all heart attacks are the same. By describing the underlying severity of heart muscle injury, it gives clinicians and researchers a clearer way to understand risk, guide future research, and identify opportunities for more individualized care. With incorporation of our concept into UDMI, the CCS classification was effectively elevated to the global stage and has now become international standard.” 

The classification identifies four stages of heart attack injury, ranging from no or minimal damage to the heart muscle to the most severe stage, hemorrhagic myocardial infarction, in which damage to heart muscle is accompanied by rupture of small blood vessels, resulting in bleeding into the heart muscle. With each progressive stage, the risk of major adverse cardiovascular events — including recurrent heart attack, death, heart failure, dangerous arrhythmia, and stroke — increases significantly. 

“UDMI is the first international guideline manuscript to adopt CCS Classification and to identify hemorrhagic myocardial infarction as the most severe form of heart attacks. Bleeding into the heart muscle is a new target for future therapies that could hopefully reduce the terrible impact of heart attacks on our patients and society”, says Dr. Rohan Dharmakumar, from Indiana University, UDMI co-author and task force member.  

Also at ESC Congress in Munich, Germany, Dr. Dharmakumar’s research group presented SHIELD-MI as a late-breaking clinical study with simultaneous publication in the European Heart Journal. This is the first time ever that a medication specifically targeted hemorrhagic myocardial infarction. The study investigated Dexrazoxane which interferes with bleeding-related iron metabolism and demonstrated proof-of concept and safety of this novel treatment approach. “Our investigation also shows that the medication was associated with smaller bleeding size and better heart function in heart attack patients”, says Dr. Dharmakumar, principal investigator of SHIELD-MI. He added that “Further studies will be needed to confirm efficacy in larger patient cohorts, but this first study breaks completely new ground in the field of acute heart attacks”.  

This emerging research underscores the potential of the CCS infarct classification to inform future prevention and treatment strategies for patients at the highest risk. The CCS will continue to work with the Canadian and international cardiovascular community to refine, disseminate, and support implementation of the classification as evidence evolves. 

About acute myocardial infarction 

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 is not receiving enough oxygen. A heart attack is a medical emergency that requires immediate intervention from a healthcare provider to help reduce and prevent permanent heart damage and death. 

About the CCS AMI Classification 

The CCS Classification of Acute Myocardial Infarction describes heart muscle damage following a heart attack in four sequential and progressively severe stages:  

• CCS Stage 1: no or minimal damage to the heart muscle;  

• CCS Stage 2: damage to the heart muscle without injury to small blood vessels;  

• CCS Stage 3: damage to the heart muscle with blockage of small blood vessels; and  

• CCS Stage 4: damage to the heart muscle with blockage and rupture of small blood vessels, resulting in bleeding into the heart muscle, also referred to as hemorrhagic myocardial infarction. 

About the Canadian Cardiovascular Society 

The Canadian Cardiovascular Society is the national voice for cardiovascular clinicians and scientists, representing cardiologists, cardiac surgeons, and other heart health specialists across Canada. CCS advances 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 more information, visit ccs.ca. 

Media contact 

Michel Hachey
Director of Communications
Canadian Cardiovascular Society
hachey@ccs.ca