Gacguidelines.ca

ACS: Unstable Angina and Non-ST-Segment Elevation Myocardial Infarction ACS: Unstable Angina (UA) and Non-ST-
Segment Elevation MI (NSTEMI)
Key Highlights from the recommended guideline:
• For initial diagnosis, use history, physical examination, 12-lead ECG and cardiac • For risk assessment, use non-invasive stress testing; go to early angiography for high- risk patients and those who do not stabilize with intensive medical treatment. • Management goals are to relieve ischemia (with nitroglycerine for most patients), start antiplatelet therapy (with ASA for most patients), and monitor (ECG, O2 saturation) to determine need for additional treatment.
Scope: This guideline is intended for physicians responsible for the initial management of patients with
known or suspected unstable angina or non-ST-segment elevation MI (NSTEMI).
How should I initially assess a patient with suspected acute coronary
syndrome (ACS)?

Chest discomfort at rest for > 20 minutes strongly consider referring immediately to an emergency department or specialized chest pain unit.
[Strength of recommendation: I] [Level of evidence: C]

• Do not assess a patient with possible ACS symptoms over the telephone only. Instead, refer to a facility where a physician can evaluate in person and a 12-lead ECG can be recorded. [Strength of
recommendation: I] [Level of evidence: C]
Use the history, physical examination, 12-lead ECG, and initial cardiac marker tests to categorize the patient’s diagnosis as o Noncardiac [Strength of recommendation: I] [Level of evidence: C]
If the patient has possible or definite ACS but a normal initial ECG and cardiac marker levels, observe with
cardiac monitoring, and repeat the ECG and cardiac markers 6-12 hours after symptom onset. [Strength
of recommendation: I] [Level of evidence: B]
If you suspect or know that the patient has ischemic heart disease and the follow-up ECG and cardiac
marker levels are normal, do a pharmacological or exercise stress test (in the emergency department, a
chest pain unit or an outpatient setting shortly after discharge). [Strength of recommendation: I] [Level
of evidence: C]
o
If the stress test is negative and the patient is at low risk, manage on an outpatient basis. [Strength of
recommendation: I] [Level of evidence: C]
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ACS: Unstable Angina and Non-ST-Segment Elevation Myocardial Infarction What is the initial management of a patient with suspected ACS?
• Relieve ischemia using: [Strength of recommendation: I except where indicated]
Nitroglycerine (NTG) as a sublingual tablet or spray, then intravenously. [Level of evidence: C] Do
not use nitrates if the patient has had sildenafil (Viagra) in the last 24 hours. [Strength of
recommendation: III] [Level of evidence: C]
Morphine sulfate i.v. if symptoms are not relieved or if the patient is severely agitated or has acute
pulmonary congestion. [Level of evidence: C]
β-blocker (first dose i.v.) if chest pain continues and the patient has no contraindications [Level of
evidence: B]
calcium channel blocker (e.g. verapamil, diltiazem) if β-blockers are contraindicated and the patient does not have other contraindications (e.g. severe LV dysfunction).
[Level of evidence: B] Do not use immediate-release dihydropyridine calcium channel blockers
without a β-blocker. [Strength of recommendation: III] [Level of evidence: A]
Supplemental oxygen for patients with cyanosis or respiratory distress. [Level of evidence: C]
An ACE inhibitor for hypertension if patient has diabetes or if patient has LV systolic dysfunction or
congestive heart failure and the NTG and β-blocker have not resolved the hypertension. [Level of
evidence: B]
[Strength of recommendation: I]
Start ASA as soon as possible, and continue indefinitely. [Level of evidence: A]
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If an inpatient cannot tolerate ASA (e.g. hypersensitive, major GI side effects), use clopidogrel.
[Level of evidence: A]
Also anticoagulate the patient with heparin (s.c. low-molecular weight heparin (LMWH) or i.v.
unfractionated heparin (UFH)). [Level of evidence: A]
Manage women and men similarly. [Level of evidence: B]
[Strength of recommendation: I]
Keep patients who still have pain while at rest on bed rest with continuous ECG monitoring. [Level of
evidence: C]
Monitor oxygen saturation and the need for supplemental oxygen (SaO2 should be > 90%) with finger
pulse oximetry or arterial blood gas measurements. [Level of evidence: C]
How do I assess a patient’s risk and need for a revascularization procedure?
Use noninvasive stress testing in [Strength of recommendation: I; Level of evidence: C]
o
Patients at low risk [See table below] who have had no ischemia or congestive heart failure at rest or low-level activity for at least 12-24 hours. Patients at intermediate risk [See table below] who have had no ischemia or congestive heart failure at rest or low-level activity for at least 2-3 days. Go directly to angiography in patients who do not stabilize despite intensive medical treatment. [Strength
of recommendation: I] [Level of evidence: B]
Also use an “early invasive strategy” (angiography) for patients with UA or NSTEMI and any of the
following (which suggest high risk): [Strength of recommendation: I] [Level of evidence: A]
o
Recurrent angina/ischemia at rest or with low level activities despite intensive anti-ischemic therapy New or presumed new ST segment depression Recurrent angina or ischemia with: congestive heart failure symptoms, an S3 gallop, or new or worsening mitral regurgitation High risk findings on noninvasive stress testing LV systolic dysfunction (e.g. ejection fraction < 0.40) History of percutaneous coronary intervention (PCI) in the past 6 months, or history of coronary artery bypass graft (CABG) Remember that women have similar indications for noninvasive and invasive testing as men. [Level of
evidence: B]
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ACS: Unstable Angina and Non-ST-Segment Elevation Myocardial Infarction Short Term Risk of Death or Nonfatal MI in Patients With Unstable Angina High Risk
At least one of the following must be present:
Accelerating tempo of ischemic symptoms in preceding 48 h Prolonged ongoing (>20 minutes) rest pain Pulmonary edema, most likely due to ischemia Angina at rest with transient ST-segment changes >0.05 mV Bundle-branch block, new or presumed new Elevated cardiac markers (TnT or TnI >0.1 ng/mL) Intermediate Risk
No high-risk features, but one of the following is present:
Prior MI, peripheral or cerebrovascular disease, or CABG, prior aspirin use Prolonged (>20 min) rest angina, now resolved, with moderate or high likelihood of CAD Rest angina (<20 min) or relieved with rest or sublingual NTG Slightly elevated (e.g., TnT >0.01 but <0.1 ng/mL) Low Risk
No high or intermediate risk features, but may have any of the following:
New-onset or progressive CCS Class III or IV angina the past 2 weeks without prolonged (>20 min) rest pain but with moderate or high likelihood of CAD (see Table 5) Normal or unchanged ECG during an episode of chest discomfort Adapted from Table 6 of Braunwald, E., Antman, E.M., Beasley, J.W., Califf, R.M., Cheitlin, M.D., Hochman, J.S. et al. (2002). ACC/AHA 2002 guideline update for the management of patients with unstable angina and non–ST-segment elevation myocardial infarction: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on the Management of Patients With Unstable Angina), p. 11. How should I manage my ACS patients after they are discharged from
hospital?
Prescribe the following medications for all patients (unless there are contraindications): [Strength of
recommendation: I]
NTG (sublingual or spray) [Level of evidence: C]
ASA 75-325 mg daily, or clopidogrel if the patient cannot tolerate ASA [Level of evidence: A], or
both for 9 months after UA/NSTEMI [Level of evidence: B]
β-blocker [Level of evidence: B]
• LDL-cholesterol is > 3.37 mmol/L [Level of evidence: A]
• LDL-cholesterol is > 2.59 mmol/L after dietary modification [Level of evidence: B]
• HDL—cholesterol < 1.03 mmol/L (with or without other lipid abnormalities) [Level of
evidence: B]
ACE inhibitor if the patient has hypertension, diabetes, congestive heart failure or LV ejection
fraction < 0.40. [Level of evidence: A]
• Ensure that the patient is instructed about how to modify cardiac risk factors: [Strength of
recommendation: I]
Lifestyle modification: smoking cessation, optimal weight, daily exercise, diet. [Level of evidence:
B]
Blood pressure control (< 130/85 mm Hg) [Level of evidence: A]
Tight glycemic control in diabetes [Level of evidence: B]
Consider referring smokers to a smoking cessation program or and/or an outpatient cardiac rehabilitation
program. [Strength of recommendation: I] [Level of evidence: B]
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ACS: Unstable Angina and Non-ST-Segment Elevation Myocardial Infarction
Levels of Evidence
The levels of evidence used to grade the recommendations in this guideline are as follows: Strength of Recommendation
Conditions for which there is evidence and/or general agreement that a given procedure or treatment is useful and effective Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment Weight of evidence/opinion is in favor of usefulness/efficacy Usefulness/efficacy is less well established by evidence/opinion Conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful/effective and in some cases may be harmful Levels of Evidence
The data were derived from multiple randomized clinical trials that involved large numbers of patients The data were derived from a limited number of randomized trials that involved small numbers of patients or from careful analyses of nonrandomized studies or observational registries. Expert consensus is the primary basis for the recommendation. The above recommendations were derived from the following GAC endorsed
guideline:
Braunwald, E., Antman, E.M., Beasley, J.W., Califf, R.M., Cheitlin, M.D., Hochman, J.S. et al. (2002). ACC/AHA 2002 guideline update for the management of patients with unstable angina and non–ST-segment elevation myocardial infarction: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on the Management of Patients With Unstable Angina). Retrieved February 22, Effective Date: November, 2006
Planned Review Date: November, 2009
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Source: http://www.gacguidelines.ca/site/GAC_Guidelines/assets/pdf/AMI07-ACS_-_Unstable_angina_Non-ST-Elevation_Mar_5_08_Final.pdf