This meta-analysis examined 58 prospective ED studies that involved diagnostic test accuracy among patients with suspected Non-ST elevation ACS.
The meta-analysis found that the following clinical findings predicted excess ACS risk in patients presenting with chest pain:
- hypotension (systolic blood pressure, <100 mm Hg; positive likelihood ratio, 3.9)
- abnormal prior stress test (LR, 3.1)
- peripheral artery disease (LR, 2.7)
- radiation to both arms (LR, 2.6)
- pain similar to prior ischemia (LR, 2.2)
ECG findings associated with ACS risk:
- ST-segment depression (LR, 5.3)
- Any T-wave inversion or Q waves (LR, 3.6).
Clinical features that argued against ACS were chest pain that was reproducible with palpation and pleuritic chest pain.
Prognostic scoring systems that predicted excess ACS risk were the HEART and TIMI scores:
- An elevated HEART score 4 or more has a positive LR 13
- An elevated TIMI score 3 or more has a positive LR 6.8
When initially evaluating a patient presenting with chest pain to the ED, it is important to calculate the patient’s HEART score, TIMI score and determine the presence of any other clinical signs predictive of ACS including hypotension, history of PAD, presence of a prior abnormal myocardial perfusion study, radiation to both arms and pain similar to prior ischemia. The absence of these factors or the presence of pain reproducible to palpation or pleuritic chest pain makes ACS unlikely.