Table 3.11-1. Types of MI based on the fourth universal definition of MI

Criteria for types 1 and 2 MIa

Type 1

MI caused by atherothrombotic event precipitated by plaque erosion or plaque rupture with thrombus formation

Type 2

Ischemic myocardial injury, usually in the setting of coronary atherosclerosis, from oxygen supply-demand mismatch without plaque erosion or rupture (eg, sudden anemia, prolonged tachyarrhythmia, coronary artery spasm or dissection, shock)

Criteria for type 3 MI

Sudden cardiac death with new ischemic ECG changes or ventricular fibrillation with symptoms suggestive of myocardial ischemia; death occurs before blood biomarkers can be obtained or before increases in biomarkers are identified

Criteria for types 4 and 5 MI (procedure-related MI within 48 hours after index procedure)b

Type 4a

PCI-related MI

Type 4b

In-stent thrombosis documented angiographically or by the same criteria as type 1 MI

Type 4c

In-stent restenosis or restenosis after balloon angioplasty documented angiographically or by the same criteria as type 1 MI

Type 5

CABG-related MI

a Rise and fall of cardiac troponins with ≥1 troponin value >99th percentile of URL along with either new ischemic ECG changes, development of pathologic Q waves, symptoms of acute myocardial ischemia, imaging evidence of new wall motion abnormality or loss of viable myocardium, or angiographic identification of coronary thrombus.

b Further specific criteria: Coronary procedure–related MI ≤48 hours after the index procedure with an elevation in cardiac troponin values >5 × >99th percentile of URL for type 4a MI, >10 × for type 5 MI in patients with normal values at baseline. Patients with elevated but stable or declining baseline values must meet the criterion of >5-fold (in type 4a) or >10-fold (in type 5) increase as well as have a change ≥20% from the baseline value. Patients must also have one of the following: new ischemic changes (type 4a MI only), new pathologic Q waves, imaging evidence of loss of viable myocardium, or angiographic findings of a procedure-related flow-limiting complication.

Adapted from Circulation. 2018;138(20):e618-e651.

CABG, coronary artery bypass graft; ECG, electrocardiography; MI, myocardial infarction; PCI, percutaneous coronary intervention; URL, upper reference limit.