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Classification of a Heart Attack

Adapted from: Thygesen K, et al.

Fourth Universal Definition of Myocardial Infarction (2018). Consensus report from the European Society of Cardiology (ESC), American College of Cardiology (ACC), the American Heart Association (AHA) and the World Heart Federation (WHF).

In this 2018 definition of myocardial infarction (MI), the recommended biomarkers for evaluation of myocardial injury and MI are troponins. Under the new universal definition, troponin is the only recommended diagnostic biomarker for MI. When troponin levels are persistently elevated and do not fall, it indicates a chronic nonischemic myocardial condition causing myocardial injury.

Type 1 MI#

Coronary artery disease with plaque rupture and coronary thrombosis (STEMI and NSTEMI).#

Detection of a rise and/or fall of cTn values with at least 1 value above the 99th percentile URL and with at least 1 of the following:

  • Symptoms of acute myocardial ischemia;
  • New ischemic ECG changes;
  • Development of pathological Q waves;
  • Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality in a pattern consistent with an ischemic etiology;
  • Identification of a coronary thrombus by angiography including intracoronary imaging or by autopsy.

Type 2 MI#

Imbalance between oxygen supply and myocardial demand without thrombosis.#

Detection of a rise and/or fall of cTn values with at least 1 value above the 99th percentile URL, and evidence of an imbalance between myocardial oxygen supply and demand unrelated to acute coronary atherothrombosis, requiring at least 1 of the following:

  • Symptoms of acute myocardial ischemia;
  • New ischemic ECG changes;
  • Development of pathological Q waves;
  • Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality in a pattern consistent with an ischemic etiology

Type 3 MI#

Myocardial infarction resulting in death when biomarker values are unavailable,#

Patients who suffer cardiac death, with symptoms suggestive of myocardial ischemia accompanied by presumed new ischemic ECG changes or ventricular fibrillation, but die before blood samples for biomarkers can be obtained, or before increases in cardiac biomarkers can be identified, or MI is detected by autopsy examination.

Type 4a. Criteria for PCI-Related MI ≤48 Hours After the Index Procedure#

Myocardial infarction related to PCI.#

Coronary intervention–related MI is arbitrarily defined by an elevation of cTn values >5 times the 99th percentile URL in patients with normal baseline values. In patients with elevated preprocedure cTn in whom the cTn level are stable (≤20% variation) or falling, the postprocedure cTn must rise by >20%. However, the absolute postprocedural value must still be at least 5 times the 99th percentile URL. In addition, 1 of the following elements is required:

  • New ischemic ECG changes;
  • Development of new pathological Q waves;
  • Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality in a pattern consistent with an ischemic etiology;
  • Angiographic findings consistent with a procedural flow-limiting complication such as coronary dissection, occlusion of a major epicardial artery or a side branch occlusion/thrombus, disruption of collateral flow, or distal embolization.

Type 4b. Criteria for CABG-Related MI ≤48 Hours After the Index Procedure#

Myocardial infarction related to stent thrombosis.#

CABG-related MI is arbitrarily defined as elevation of cTn values >10 times the 99th percentile URL in patients with normal baseline cTn values. In patients with elevated preprocedure cTn in whom cTn levels are stable (≤20% variation or falling, the postprocedure cTn must rise by >20%. However, the absolute postprocedural value still must be >10 times the 99th percentile URL. In addition, 1 of the following elements is required:

  • Development of new pathological Q waves;
  • Angiographic documented new graft occlusion or new native coronary artery occlusion;
  • Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality in a pattern consistent with an ischemic etiology.

Type 4c. Myocardial infarction due to restenosis ≥50% after an initially successful PCI.#

Type 5. Myocardial infarction related to coronary artery bypass grafting.#

** NSTEMI=non-ST-elevation MI; PCI=percutaneous coronary intervention; STEMI=ST-elevation MI; cTn=cardiac troponin; ECG=electrocardiogram; URL=upper reference limit.

  • ST-elevation MI (STEMI) is a complete blockage of the coronary artery.
  • Non-ST-elevation MI (NSTEMI) is a partial blockage of the coronary artery.

Related Pages#

References/Websites#