Clinical event adjudication: Myocardial infarction
For the list of clinical event adjudication definitions, click here

# Myocardial infarction
This chapter presents myocardial infarction definitions used in the Clinical Event Committee adjudication processes. These definitions are current as of 3/26/10.

# 1. Criteria for Acute Myocardial Infarction

## a. Spontaneous MI
- Symptoms of ischemia
- ECG changes indicative of new ischemia 
- Development of pathological Q waves* in the ECG
- Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality
- ST elevationNew ST elevation at the J point in two anatomically contiguous leads with the cut-off points:   0.2 mV in men (> 0.25 mV in men < 40 years) or  0.15 mV in women in leads V2-V3 and/or  0.1 mV in other leads.
- ST depression and T-wave changesNew horizontal or down-sloping ST depression  0.05 mV in two contiguous leads; and/or new T inversion  0.1 mV in two contiguous leads.
- Any Q-wave in leads V2-V3  0.02 seconds or QS complex in leads V2 and V3
- Q-wave  0.03 seconds and  0.1 mV deep or QS complex in leads I, II, aVL, aVF, or V4-V6 in any two leads of a contiguous lead grouping (I, aVL, V6; V4-V6; II, III, and aVF)a

## b. Percutaneous Coronary Intervention-Related Myocardial Infarction

## c. Coronary Artery Bypass Grafting-Related Myocardial Infarction
- either new pathological Q waves in at least 2 contiguous leads that persist through 30 days or new persistent non-rate related LBBB or
- angiographically documented new graft or native coronary artery occlusion or other complication in the operating room resulting in loss of myocardium or
- imaging evidence of new loss of viable myocardium

## d. Pathological findings of an acute myocardial infarction
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# 2. Criteria for Silent Myocardial Infarction or Prior Myocardial Infarction (with or without Symptoms)
- Appearance of new persistent pathological Q waves.  A confirmatory ECG is recommended if there have been no clinical symptoms or history of myocardial infarction.
- Imaging evidence of a region of loss of viable myocardium that is thinned and fails to contract, in the absence of a non-ischemic cause
- Pathological findings of a healed or healing myocardial infarction
- Any Q-wave in leads V2-V3  0.02 seconds or QS complex in leads V2 and V3
- Q-wave  0.03 seconds and  0.1 mV deep or QS complex in leads I, II, aVL, aVF, or V4-V6 in any two leads of a contiguous lead grouping (I, aVL, V6; V4-V6; II, III, and aVF)a
- R-wave  0.04 seconds in V1-V2 and R/S  1 with a concordant positive T-wave in the absence of a conduction defect
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# 3. Criteria for Reinfarction
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# 4. Clinical Classification of Different Types of Myocardial Infarction
- Type 1Spontaneous myocardial infarction related to ischemia due to a primary coronary event such as plaque erosion and/or rupture, fissuring, or dissection
- Type 2Myocardial infarction secondary to ischemia due to either increased oxygen demand or decreased supply, e.g. coronary artery spasm, coronary embolism, anemia, arrhythmias, hypertension, or hypotension
- Type 3Sudden unexpected cardiac death, including cardiac arrest, often with symptoms suggestive of myocardial ischemia, accompanied by presumably new ST elevation, or new LBBB, or evidence of fresh thrombus in a coronary artery by angiography and/or at autopsy, but death occurring before blood samples could be obtained, or at a time before the appearance of cardiac biomarkers in the blood
- Type 4aMyocardial infarction associated with PCI
- Type 4bMyocardial infarction associated with stent thrombosis as documented by angiography or at autopsy
- Type 5Myocardial infarction associated with CABG
- ST-Elevation MI (STEMI)
Also categorize as:
Q-wave
Non-Q-wave
Unknown (no ECG or ECG not interpretable)
- Also categorize as:
Q-wave
Non-Q-wave
Unknown (no ECG or ECG not interpretable)
- Q-wave
- Non-Q-wave
- Unknown (no ECG or ECG not interpretable)
- Non-ST-Elevation MI (NSTEMI)
Also categorize as:
Q-wave
Non-Q-wave
Unknown (no ECG or ECG not interpretable)
- Also categorize as:
Q-wave
Non-Q-wave
Unknown (no ECG or ECG not interpretable)
- Q-wave
- Non-Q-wave
- Unknown (no ECG or ECG not interpretable)
- Unknown (no ECG or ECG not interpretable)
- Reporting MI type by treatment group as follows:Table 1.  Sample Clinical Trial Tabulation of Randomized Patients by
- Reporting data as multiples of the 99th percentile URL of the applied biomarker as follows:
Table 2.  Classification of the Different Types of Myocardial Infarction According to Multiples of the 99th Percentile URL of the Applied Cardiac Biomarker
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# General Considerations
- For a diagnosis of acute myocardial infarction, elevation of cardiac biomarkers should be present.  However, myocardial infarction may be adjudicated for an event that has characteristics (i.e., ischemic symptoms) of a myocardial infarction but which does not meet the strict definition because biomarker or electrocardiographic results are not available (e.g. not measured) or are non-contributory (e.g. may have normalized).
- Whenever possible, all investigators within a clinical trial should employ the same cardiac troponin assay in order to reduce the inter-assay variability.  If reasonable, using a core laboratory with the same assay for all measurements would be optimal.
- Entry criteria for the diagnosis of myocardial infarction in clinical trials may be different than endpoint criteria.  For example, use of prior myocardial infarction as an entry criterion may require documentation in the record of prior MI and clinical details; however, cardiac enzymes, 12-lead ECG evidence, and cardiac catheterization/percutaneous coronary intervention results may not be required.
- For procedure-related myocardial infarction, all available biomarker information will be taken into account.  Furthermore, in cases where the cardiac biomarker is elevated prior to PCI or CABG, the  20% increase of the value in the secondary cardiac biomarker sample within 48 hours of PCI and within 72 hours of CABG, per the Universal MI definition, is somewhat arbitrary.  Some studies may want to use a different percentage, such as  50% increase.  Data should be collected in such a way that analyses using  20% or  50% could both be performed.
- There is considerable discussion that in the setting of PCI or CABG, a three-fold increase in CK-MB may not be equivalent to a three-fold increase in troponin and that a five-fold increase in CK-MB may not be equivalent to a five-fold increase in troponin, respectively.  Furthermore, it is unclear if this biomarker elevation by itself requires additional confirmation with new ECG changes, procedural complications, or new imaging evidence similar to that required for spontaneous myocardial infarctions or myocardial infarctions occurring in the setting of CABG.
- The prognostic significance of different types of myocardial infarctions (e.g., periprocedural myocardial infarction versus spontaneous myocardial infarction) may be different, and outcomes should be evaluated separately for these two subsets of patients.
- Not infrequently, patients with renal disease or congestive heart failure may have elevated cardiac biomarkers.  In these circumstances, the Clinical Endpoints Committee must use the totality of the evidence to determine whether the cardiac biomarker elevation or underlying condition represents the primary process or endpoint event.