7
Table 5. Cardiac Biomarkers and the Universal
Definition of MI
Recommendations
COR LOE
Diagnosis
Cardiac-specific troponin (troponin I or T when a contemporary
assay is used) levels should be measured at presentation and 3-6 h
aer symptom onset in all patients who present with symptoms
consistent with ACS to identify a rising and/or falling pattern.
I A
Additional troponin levels should be obtained beyond 6 h aer
symptom onset in patients with normal troponins on serial
examination when electrocardiographic changes and/or clinical
presentation confer an intermediate or high index of suspicion
for ACS.
I A
If the time of symptom onset is ambiguous, the time of presentation
should be considered the time of onset for assessing troponin values.
I A
With contemporary troponin assays, creatine kinase myocardial
isoenzyme (CK-MB) and myoglobin are NOT useful for diagnosis
of ACS.
III: No
Benefit
A
Prognosis
e presence and magnitude of troponin elevations are useful for
short- and long-term prognosis.
I B
It may be reasonable to remeasure troponin once on day 3 or day 4
in patients with an MI as an index of infarct size and dynamics of
necrosis.
IIb B
Use of selected newer biomarkers, especially B-type natriuretic
peptide, may be reasonable to provide additional prognostic
information.
IIb B
