Table 5

Summary of Recommendations for Cardiac Biomarkers and the Universal Definition of MI

Measure cardiac-specific troponin (troponin I or T) at presentation and 3—6 h after symptom onset in all patients with suspected ACS to identify pattern of valuesIA(21,64,67–71,152–156)
Obtain additional troponin levels beyond 6 h in patients with initial normal serial troponins with electrocardiographic changes and/or intermediate/high risk clinical featuresIA(21,72–74,157)
Consider time of presentation the time of onset with ambiguous symptom onset for assessing troponin valuesIA(67,68,72)
With contemporary troponin assays, CK-MB and myoglobin are not useful for diagnosis of ACSIII: No BenefitA(158–164)
Troponin elevations are useful for short- and long-term prognosisIB(71,73,165,166)
Remeasurement of troponin value once on d 3 or 4 in patients with MI may be reasonable as an index of infarct size and dynamics of necrosisIIbB(164,165)
BNP may be reasonable for additional prognostic informationIIbB(87,88,167–171)

ACS indicates acute coronary syndromes; BNP, B-type natriuretic peptide; CK-MB, creatine kinase myocardial isoenzyme; COR, Class of Recommendation; LOE, Level of Evidence; and MI, myocardial infarction.