ACS - Risk Stratification

Likelihood That Signs/Symptoms represent ACS 2/2 CAD

Feature	High Likelihood (any of the following)	Intermediate Likelihood (absence of high-likelihood features and presence of any of the following)	Low Likelihood (absence of high- or intermediate-likelihood features but may have)
History	Chest or left arm pain or discomfort as chief symptom reproducing prior documented angina	Chest or left arm pain or discomfort as chief symptom	Probable ischemic symptoms in absence of any of the intermediate-likelihood characteristics
	Known history of coronary artery disease, including myocardial infarction	Age >70 y old	Recent cocaine use
		Male sex
		Diabetes mellitus
Examination	Transient mitral regurgitation murmur, hypotension, diaphoresis, pulmonary edema, or rales	Extracardiac vascular disease	Chest discomfort reproduced by palpation
ECG	New, or presumably new, transient ST-segment deviation (1 mm or greater) or T-wave inversion in multiple precordial leads	Fixed Q waves	T-wave flattening or inversion <1 mm in leads with dominant R waves
		ST depression 0.5–1.0 mm or T-wave inversion >1 mm
			Normal ECG
Cardiac markers	Elevated cardiac troponin I, troponin T, or MB fraction of creatine kinase	Normal	Normal

Short-Term Risk of Death or Nonfatal Myocardial Infarction by Risk Stratification in Patients with Unstable Angina

Feature	High Likelihood (at least one of the following features must be present)	Intermediate Likelihood (no high-risk feature, but must have one of the following)	Low Likelihood (no high- or intermediate-risk feature, but may have any of the following)
History	Accelerating tempo of ischemic symptoms in preceding 48 h	Prior myocardial infarction, peripheral or cerebrovascular disease, or coronary artery bypass grafting; prior aspirin use	—
Character of the pain	Prolonged ongoing (>20 min) rest pain	Prolonged (>20 min) rest angina, now resolved, with moderate or high likelihood of CAD	Increased angina frequency, severity, or duration
		Rest angina (>20 min) or relieved with rest or sublingual nitroglycerin	Angina provoked at a lower threshold
			New-onset angina with onset 2 wk to 2 mo before presentation
		Nocturnal angina
		New-onset or progressive Canadian Cardiology Society Class III or IV angina (Table 53-0.1) in the past 2 wk without prolonged (>20 min) rest pain but with intermediate or high likelihood of CAD (Table 53-2)
Clinical findings	Pulmonary edema, most likely due to ischemia	Age >70 y old	Chest discomfort reproduced by palpation
	New or worsening mitral regurgitation murmur
	S3 or new/worsening rales
	Hypotension, bradycardia, tachycardia
	Age >75 y old
ECG	Angina at rest with transient ST-segment changes >0.5 mm	T-wave changes, pathologic Q waves, or resting ST depression <1 mm in multiple lead groups (anterior, inferior, lateral)	Normal or unchanged ECG
	Bundle-branch block, new or presumed new
	Sustained ventricular tachycardia
Cardiac markers	Elevated cardiac TnT, TnI, or CK-MB (e.g., TnT or TnI >0.1 nanogram/mL)	Slightly elevated cardiac TnT, TnI, or CK-MB (e.g., TnT >0.01 but <0.1 nanogram/mL)	Normal

Source:

2007 ACC/AHA Guidelines for the Management of Patients with UA/NSTEMI