ACS - Risk Stratification

HEART Score

• The score has been derived and validated in an ED population and predicts 6 week adverse cardiac events

• Low risk patients have a score 0-3 and have a less than 2% risk of MACE at 6 weeks.

Criteria	Point Value
History
Highly Suspicious	+2
Moderately Suspicious	+1
Slightly Suspicious	0
ECG
Significant ST-depression	+2
Non specific repolarisation disturbance	+1
Normal	0
Age
≥ 65	+2
45-65	+1
≤ 45	0
Risk Factors (Hypercholesterolemia, Hypertension, Diabetes Mellitus, Smoking,Obesity)
≥ 3 risk factors or history of atherosclerotic disease	+2
1-2 risk factors	+1
No risk factors known	0
Troponin
≥ 3× normal limit	+2
1-3× normal limit	+1
≤ normal limit	0

• 0-3: 2.5% risk of adverse cardiac event. Patient's can be discharged with follow-up.
• 4-6: 20.3% risk of adverse cardiac event. Patients should be admitted to the hospital for trending of troponin and provocative testing.
• ≥7: 72.7% risk of adverse cardiac event, suggesting early invasive measures with these patients and close coordination with inpatient cardiology

New Vancouver Chest Pain Rule

• Useful for screening patient with low risk for ACS
• The old Vancouver chest pain rule was not properly validated
• The new rule was validated in 2014 on 1635 patients and published in 2014
• With high sensitivity troponins the sensitivity is 99.1% (95% CI 97.4-99.7), & specificity is 16.1 (95% CI 14.2-18.2)
• With sensitive troponin-I the sensitivity was 98.8% (97.0-99.5), & specificity of 15.8 (13.9-17.9)

Algorithm

• Is the same for c-TnI assay and hs-TnI assay but sensitivity differences by a percentage point

1. Is there an abnormal ECG, positive troponin at 2 hrs or prior ACS nitrate use?
   • If Yes to any then no early discharge
2. Does palpation reproduce the pain?
   • If Yes then early discharge
3. Age ≥50, or does pain radiate to neck, jaw, or left arm?
   • If Yes then no early discharge

• If answer is No to all of the above stepwise questions then the patient can have early discharge with close follow-up for further provocative testing

Likelihood That Signs/Symptoms Represent ACS due to 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 Composite Outcome

Composite Outcome: 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 in the past 2 wk without prolonged (>20 min) rest pain but with intermediate or high likelihood of CAD;
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

TIMI Risk Stratification Score

NSTEMI TIMI Score

Used to estimate percent risk of all-cause mortality, new/recurrent MI, or need for revascularization at 14 days

• Age >65 yrs (1 point)
• Three or more risk factors for coronary artery disease: (1 point)
  • family history of coronary artery disease
  • hypertension
  • hypercholesterolaemia
  • diabetes
  • current smoker
• Use of aspirin in the past 7 days (1 point)
• Significant coronary stenosis (stenosis >50%) (1 point)
• Severe angina (e.g., >2 angina events in past 24 h or persisting discomfort) (1 point)
• ST-segment deviation of ≥0.05 mV on first ECG (1 point)
• Increased troponin and/or creatine kinase-MB blood tests (1 point)

TIMI Risks

points	% risk of mortality, MI, or need for revascularization
0	5%
1	5%
2	8%
3	13%
4	20%
5	26%
6	41%

See Also

• Acute Coronary Syndrome (Main)
• ADAPT Trial