Unstable angina non ST elevation myocardial infarction immediate management

Unstable angina pectoris
ICD-10	I20
ICD-9	413
DiseasesDB	8695
eMedicine	med/133
MeSH	D000787

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]; Smita Kohli, M.D.; Neil Gheewala, M.D. [3]; Varun Kumar, M.B.B.S.; Lakshmi Gopalakrishnan, M.B.B.S.

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Overview

Initial management of acute coronary syndorme (ACS) begins with differentiating between the spectrum of ACS which includes STEMI, Unstable Angina and Non-ST Elevation Myocardial Infarction.

Because the symptoms for all these can be similar, a medical evaluation is necessary as mentioned in earlier sections (see Pre-hospital Care and Initial Therapy). Information from the history, physical examination, 12-lead ECG, and initial cardiac biomarker tests can help in differentiating between the above three categories as well as categorize the patient into probable or definite ACS, chronic stable angina or non-cardiac cause of chest pain.

• Patients with STEMI must be evaluated for immediate reperfusion therapy (see Reperfusion Therapy (Overview of Fibrinolysis and Primary PCI)).
• Patients with Unstable angina/NSTEMI, recurrent symptoms suggestive of ACS and/or electrocardiogram ST-segment deviations, or positive cardiac biomarkers who are hemodynamically stable should be admitted to an inpatient unit for bed rest with continuous rhythm monitoring and careful observation for recurrent ischemia and managed with either an invasive or conservative strategy(see Initial conservative versus initial invasive strategies).

Risk stratification

Risk Stratification and Prognosis early in the course of admission is important so that patients who are classified as intermediate to high risk, including those with ongoing ischemia and evidence of hemodynamic instability should be admitted to a critical care unit, whenever possible.

Once a patient with documented high-risk ACS is admitted, standard medical therapy is indicated which includes Oxygen, ASA, Beta Blockers, Anticoagulant Therapy, Antiplatelet Therapy with a GP IIb/IIIa inhibitor, and a thienopyridine(for example clopidogrel), unless contraindicated.

Immediate Management

You can read in greater detail about each of the therapies below in greater detail by clicking on the link for that therapy.

Oxygen | Nitrates | Analgesics | Beta Blockers | Calcium Channel Blocker | Inhibitors of Renin-Angiotensin-Aldosterone axis

ACC / AHA Guidelines (DO NOT EDIT)

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Class I 1. Bed/chair rest with continuous ECG monitoring is recommended for all Unstable angina / NSTEMI patients during the early hospital phase. (Level of Evidence: C) [1] [2] 2. Supplemental oxygen should be administered to patients with Unstable angina / NSTEMI with an arterial saturation <90%, respiratory distress, or other high risk features for hypoxemia. (Pulse oximetry is useful for continuous measurement of SaO²) (Level of Evidence: B) 3. Patients with Unstable angina / NSTEMI with ongoing ischemic discomfort should receive sublingual nitroglycerine (NTG) (0.4 mg) every 5 min for a total of 3 doses, after which assessment should be made about the need for intravenous NTG, if not contraindicated. (Level of Evidence: C) 4. Intravenous NTG is indicated in the first 48 h after Unstable angina / NSTEMI for treatment of persistent ischemia, heart failure, or hypertension. The decision to administer intravenous NTG and the dose used should not preclude therapy with other proven mortality reducing interventions such as beta blockers or ACE inhibitors. (Level of Evidence: B) 5. Oral beta blocker therapy should be initiated within the first 24 h for patients who do not have 1 or more of the following: a- Signs of heart failure, b- Evidence of a low output state, c- Increased risk for cardiogenic shock, or d- Other relative contraindications to beta blockade (PR interval >0.24 sec, second or third degree heart block, active asthma, or reactive airway disease). (Level of Evidence: B) 6. In Unstable angina / NSTEMI patients with continuing or frequently recurring ischemia and in whom beta blockers are contraindicated, a non dihydropyridine calcium channel blocker (e.g., verapamil or diltiazem) should be given as initial therapy in the absence of clinically significant left ventricular dysfunction or other contraindications. (Level of Evidence: B) 7. An Angiotensin Converting Enzyme inhibitor (ACEI) should be administered orally within the first 24 h to Unstable angina / NSTEMI patients with pulmonary congestion or LV ejection fraction (LVEF) ≤40%, in the absence of hypotension (systolic blood pressure <100 mmHg or <30 mmHg below baseline) or known contraindications to that class of medications. (Level of Evidence: A) 8. An angiotensin receptor blocker should be administered to Unstable angina / NSTEMI patients who are intolerant of ACE inhibitors and have either clinical or radiological signs of HF or LVEF ≤40%. (Level of Evidence: A) 9. Because of the increased risks of mortality, reinfarction, hypertension, HF, and myocardial rupture associated with their use, non steroidal anti-inflammatory drugs (NSAIDs), except for ASA, whether non selective or cyclo oxygenase (COX)-2–selective agents, should be discontinued at the time a patient presents with Unstable angina / NSTEMI. (Level of Evidence: C) Class IIa 1. It is reasonable to administer supplemental oxygen to all patients with Unstable angina / NSTEMI during the first 6 h after presentation. (Level of Evidence: C) 2. In the absence of contradictions to its use, it is reasonable to administer morphine sulfate intravenously to Unstable angina / NSTEMI patients if there is uncontrolled ischemic chest discomfort despite NTG, provided that additional therapy is used to manage the underlying ischemia. (Level of Evidence: B) 3. It is reasonable to administer intravenous (IV) beta blockers at the time of presentation for hypertension to Unstable angina / NSTEMI patients who do not have 1 or more of the following: a- Signs of HF, b- Evidence of a low output state, c- Increased risk for cardiogenic shock, d- Other relative contraindications to beta blockade (PR interval >0.24 s, second or third degree heart block, active asthma, or reactive airway disease). (Level of Evidence: B) 4. Oral long acting non dihydropyridine calcium antagonists are reasonable for use in Unstable angina / NSTEMI patients for recurrent ischemia in the absence of contraindications after beta blockers and nitrates have been fully used. (Level of Evidence: C) 5. An ACE inhibitor administered orally within the first 24 h of Unstable angina / NSTEMI can be useful in patients without pulmonary congestion or LVEF ≤40% in the absence of hypotension (systolic blood pressure <100 mm Hg or less than 30 mm Hg below baseline) or known contraindications to that class of medications. (Level of Evidence: B) 6. Intra aortic balloon pump (IABP) counter pulsation is reasonable in Unstable angina / NSTEMI patients for severe ischemia that is continuing or recurs frequently despite intensive medical therapy, for hemodynamic instability in patients before or after coronary angiography, and for mechanical complications of myocardial infarction (MI). (Level of Evidence: C) Class IIb 1. The use of extended-release forms of non dihydropyridine calcium antagonists instead of a beta blocker may be considered in patients with Unstable angina / NSTEMI. (Level of Evidence: B) 2. Immediate-release dihydropyridine calcium antagonists in the presence of adequate beta blockade may be considered in patients with Unstable angina / NSTEMI with ongoing ischemic symptoms or hypertension. (Level of Evidence: B) Class III 1. NTG should not be administered to Unstable angina / NSTEMI patients with systolic blood pressure <90mmHg or ≥30 mmHg below baseline, severe bradycardia (<50 bpm), tachycardia (>100 bpm) in the absence of symptomatic heart failure, or right ventricular infarction. (Level of Evidence: C) 2. Nitroglycerin or other nitrates should not be administered to patients with Unstable angina / NSTEMI who had received a phosphodiesterase inhibitor for erectile dysfunction within 24 h of sildenafil or 48 h of tadalafil use. The suitable time for the administration of nitrates after vardenafil has not been determined. (Level of Evidence: C) 3. Immediate-release dihydropyridine calcium antagonists should not be administered to patients with Unstable angina / NSTEMI in the absence of a beta blocker. (Level of Evidence: A) 4. An intravenous ACE inhibitor should not be given to patients within the first 24 h of Unstable angina / NSTEMI because of the increased risk of hypotension. (A possible exception may be patients with refractory hypertension.) (Level of Evidence: B) 5. It may be harmful to administer intravenous beta blockers to Unstable angina / NSTEMI patients who have contraindications to beta blockade, signs of HF or low output state, or other risk factors for cardiogenic shock. (Level of Evidence: A) 6. Non steroidal anti-inflammatory drugs (except for ASA), whether non selective or COX-2–selective agents, should not be administered during hospitalization for Unstable angina / NSTEMI because of the increased risks of mortality, reinfarction, hypertension, heart failure, and myocardial rupture associated with their use. (Level of Evidence: C)

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See Also

• The UA / NSTEMI Living Guidelines: Vote on current recommendations and suggest revisions to the guidelines

Sources

• 2011 ACCF/AHA Focused Update Incorporated Into the ACC/AHA 2007 Guidelines for the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines
• The ACC/AHA 2007 Guidelines for the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction