Heart attacks, or acute myocardial infarction (MI), are one of the leading causes of death worldwide. The newly released Canadian Cardiovascular Society Classification of Acute Myocardial Infarction (CCS-AMI) appearing in the Canadian Journal of Cardiology, published by Elsevier, presents a four-stage classification of heart attack based on heart muscle damage. This work by a group of noted experts has the potential to stratify risk more accurately in heart attack patients and lays the groundwork for development of new, injury-stage-specific and tissue pathology-based therapies.