6
Diagnosis
Table 4. Prognosis—Early Risk Stratification
Recommendations
COR LOE
In patients with chest pain or other symptoms suggestive of ACS, a
12-lead ECG should be performed and evaluated for ischemic changes
within 10 min of the patient's arrival at an emergency facility.
I C
If the initial ECG is not diagnostic but the patient remains
symptomatic and there is a high clinical suspicion for ACS, serial
ECGs (e.g., 15- to 30-minute intervals during the first hour) should
be performed to detect ischemic changes.
I C
Serial cardiac troponin I or T levels (when a contemporary assay is
used) should be obtained at presentation and 3-6 h aer symptom
onset
a
in all patients who present with symptoms consistent with
ACS to identify a rising and/or falling pattern of values.
I A
Additional troponin levels should be obtained beyond 6 h aer
symptom onset
a
in patients with normal troponin levels on serial
examination when changes on ECG and/or clinical presentation
confer an intermediate or high index of suspicion for ACS.
I A
Risk scores should be used to assess prognosis in patients with
NSTE-ACS.
I A
Risk-stratification models can be useful in management. IIa B
It is reasonable to obtain supplemental electrocardiographic leads
V
7
-
V
9
in patients whose initial ECG is nondiagnostic and who are at
intermediate/high risk of ACS.
IIa B
Continuous monitoring with 12-lead ECG may be a reasonable
alternative in patients whose initial ECG is nondiagnostic and who
are at intermediate/high risk of ACS.
IIb B
Measurement of B-type natriuretic peptide or N-terminal pro–B-
type natriuretic peptide may be considered to assess risk in patients
with suspected ACS.
IIb B
a
If the time of symptom onset is ambiguous, the time of presentation should be considered the time
of onset for assessing troponin values (COR I, LOE A).
