Sandbox Rim
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Andrea Tamayo Soto [2]; Rim Halaby, M.D. [3]
Unstable angina/ NSTEMI Resident Survival Guide Microchapters |
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Overview |
Causes |
FIRE |
Diagnosis |
Treatment |
Pre-Discharge Care |
Long Term Management |
Do's |
Don'ts |
Overview
Unstable angina and non ST elevation myocardial infarction (NSTEMI) belong to two different ends of the spectrum of acute coronary syndrome. These conditions have a similar clinical presentation characterized by an acute onset of chest pain that starts on minimal exertion, rest or sleep, lasts at least 20 minutes (but usually less that half an hour) and, is not relieved by medications or rest. NSTEMI is differentiated from unstable angina by the presence of elevated cardiac biomarkers secondary to myocardial injury. Unstabel angina and NSTEMI might not be differentiated early following the occurrence of symptoms because cardiac biomarkers may require a few hours to rise.
Causes
Life Threatening Causes
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated. Unstable angina and NSTEMI are life-threatening conditions and must be treated as such irrespective of the causes.
Common Causes
Myocardial Infarction
- Atherosclerotic plaque rupture and subsequent coronary thrombus (most common cause)
- Coronary artery spasm
- Arrhythmia
- Post-myocardial infarction
- Post-percutaneous coronary intervention
- Post-coronary artery bypass graft
- Graft closure
- New lesion in the graft
For a complete list of causes, click here for unstable angina and here for NSTEMI.
FIRE: Focused Initial Rapid Evaluation
A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention based on the 2012 ACCF/AHA focused update of the guideline for the management of patients with unstable angina/non-ST-elevation myocardial infarction.[1] An invasive strategy is defined as diagnostic angiography with the intention of revascularization.
Boxes in the red color signify that an urgent management is needed.
Identify cardinal findings of unstable angina/ NSTEMI : ❑ Chest pain or chest discomfort
❑ Characteristic ECG changes consistent with unstable angina/ NSTEMI
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Rule out life threatening alternative diagnoses: ❑ Aortic dissection (suggestive findings: vomiting, subcutaneous emphysema) | |||||||||||||||||||||||||||||||||||
Begin initial treatment: ❑ Administer 162 to 325 mg of non enteric aspirin,orally, crushed or chewed (I-A)
❑ Administer 2-4 L/min oxygen via nasal cannula when saturation <90% (I-C)
❑ Administer nitroglycerin
Contraindicated in suspected right ventricular MI, recent use of phosphodiesterase inhibitors, decreased blood pressure 30 mmHg below baseline
Contraindicated in heart failure, bradycardia, hypotension (SBP<90 mmHg), second or third degree AV block, reactive airway disease, high risk of cardiogenic shock and low cardiac output state
❑ Administer 80 mg atorvastatin (I-A) | |||||||||||||||||||||||||||||||||||
TRIAGE FOR IMMEDIATE INTERVENTION Does the patient have ANY of the following indications that require immediate angiography and revascularization ? ❑ Hemodynamic instability or cardiogenic shock, OR | |||||||||||||||||||||||||||||||||||
YES | NO | ||||||||||||||||||||||||||||||||||
Does the patient have no ECG changes AND no rise in cardiac biomarkers > 99th percentile of ULN? | |||||||||||||||||||||||||||||||||||
Yes. The patient has no ECG changes AND no rise in cardiac biomarkers > 99th percentile of ULN. | No. The patient has either positive ECG changes, OR rise in cardiac biomarkers, OR both. | ||||||||||||||||||||||||||||||||||
Repeat ECG and biomarkers within next 3 hours and 6 hours Does the patient still have no ECG changes AND no rise in cardiac biomarkers? | |||||||||||||||||||||||||||||||||||
Yes. The patient has no ECG changes AND no rise in cardiac biomarkers. | No. The patient has either positive ECG changes, OR rise in cardiac biomarkers, OR both. | ||||||||||||||||||||||||||||||||||
TRIAGE FOR INITIAL CONSERVATIVE OR INVASIVE THERAPY Calculate the risk of future adverse clinical outcomes: ❑ Thrombolysis in Myocardial Infarction (TIMI) risk score, OR ❑ GRACE score | |||||||||||||||||||||||||||||||||||
Intermediate or high risk | Low risk | ||||||||||||||||||||||||||||||||||
INITIAL INVASIVE THERAPY (IMMEDIATELY) | INITIAL INVASIVE THERAPY (4 to 48 hours) | INITIAL CONSERVATIVE THERAPY | |||||||||||||||||||||||||||||||||
Initiate ONE of the following anticoagulant therapy (I-A) ❑ Enoxaparin (I-A)
OR
❑ Bivalirudin (I-B)
Prasugrel is contraindicated in case of prior history of strokes or TIAs, active pathological bleeding, age ≥75 years, when urgent coronary artery bypass graft surgery (CABG) is likely, body weight <60 kg, propensity to bleed, concomitant use of medications that increase the risk of bleeding
| Initiate ONE of the following anticoagulant therapy (I-A) ❑ Enoxaparin (I-A)
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TRIAGE FOR NEED OF INVASIVE THERAPY Does the patient experience ANY of the following? ❑ Recurrence of symptoms, OR | |||||||||||||||||||||||||||||||||||
YES | NO | ||||||||||||||||||||||||||||||||||
PROCEED TO INVASIVE THERAPY (I-A) Administer ONE of the following antiplatelet agents if not already administered (I-A):
❑ P2Y12 receptor inhibitors
❑ IV GP IIb/IIIa inhibitors (I-A)
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High risk on stress test | Low risk on stress test OR did not undergo stress test | ||||||||||||||||||||||||||||||||||
INVASIVE THERAPY ❑ Perform diagnostic angiography (I-A) | |||||||||||||||||||||||||||||||||||
❑ Continue aspirin for life (I-A) ❑ Continue P2Y12 receptor inhibitors up to 12 months (I-B)
❑ Discontinue GP IIb/IIIa inhibitors if administered earlier (I-A)
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TRIAGE FOR SUBSEQUENT THERAPY PLAN FOLLOWING ANGIOGRAPHY Does the angiography show coronary vessel obstruction ? | |||||||||||||||||||||||||||||||||||
No | Yes | ||||||||||||||||||||||||||||||||||
❑ 1 or 2 vessel disease CABG or medical therapy might also be considered | ❑ Left main coronary artery disease ❑ 3 vessel disease ❑ 2 vessel disease with proximal left anterior descending artery affection ❑ Left ventricular dysfunction ❑Patient treated from diabetes | ||||||||||||||||||||||||||||||||||
Medical treatment | PCI | CABG | Medical treatment | ||||||||||||||||||||||||||||||||
❑ Administer aspirin indefinitely | ❑ Administer aspirin for life (I-B)
❑ Initiate/continue GPI (if not treated with bivalirudin at the time of PCI):
❑ Initiate/Continue anticoagulant therapy:
| ❑ Continue aspirin (I-B)
❑ Manage the P2Y12 receptor inhibitor therapy as follows:
If CABG can be delayed:
If CABG is urgent:
❑ Manage the anticoagulation therapy
| ❑ Continue aspirin (I-A) ❑ Administer a loading dose of P2Y12 receptor inhibitors if not given before angiography (I-B)
❑ Discontinue IV GP IIb/IIIa inhibitors if started before angiography (I-B)
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Complete Diagnostic Approach
A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention.[1]
Abbreviations: CABG: coronary artery bypass graft; ECG: electrocardiogram; LAD: left anterior descending; LBBB: left bundle branch block; MI: myocardial infarction; PCI: percutaneous coronary intervention; S3: third heart sound; S4: fourth heart sound; VSD: ventricular septal defect
Characterize the symptoms: ❑ Chest pain or chest discomfort
❑ Dyspnea | |||||||||
Obtain a detailed history: ❑ Age
❑ List of medications Identify possible triggers: | |||||||||
Examine the patient: Vital signs
Pulses
Skin Heart
❑ Murmurs
❑ Pericardial friction rub (suggestive of pericarditis) Lungs | |||||||||
Order labs and tests: ❑ EKG
❑ Echocardiography
❑ Creatinine | |||||||||
Pre-Discharge Care
Abbreviations: ACE: angiotensin converting enzyme; LVEF: left ventricular ejection fraction; PCI: percutaneous coronary intervention; PO: per os; VF: ventricular fibrillation; VT: ventricular tachycardia
Administer the following medications in patients without contraindications: ❑ Aspirin 81-325 mg (indefinitely) (I-A)
❑ Beta blockers
❑ Calcium channel blockers are used as anti-ischemic or antihypertensive drugs and also in atrial fibrillation when beta blockers are contraindicated Administer ONE of the following antiplatelet therapy for a duration of:
❑ Clopidogrel 75 mg daily, OR Consider earlier discontinuation in case bleeding risk exceeds benefit of the antiplatelet therapy (I-C). Assess the patient for ischemia: | |||||||||
Abbreviations: ACE: angiotensin converting enzyme; ARB: angiotensin receptor blocker;
❑ Prepare a list of all the home medications and educate the patient about compliance
❑ Encourage lifestyle modification
❑ Ensure the initiation of the management of comorbidities
❑ Educate the patient about the early recognition of symptoms of acute coronary syndrome ❑ Educate the patient about the use of nitroglycerin 0.4 mg, sublingually, up to 3 doses every 5 minutes | |||||||
Do's
- Administer a loading dose followed by a maintenance dose of clopidogrel, ticagrelor or prasugrel (if PCI is planned) as initial treatment instead of aspirin among patients with gastrointestinal intolerance or hypersensitivity reaction to aspirin.
- Administer sublingual nitroglycerin in patients with ischemic chest pain; however, administer IV nitroglycerin among patients with persistent chest pain after three sublingual nitroglycerin.[6]
- If fondaparinux is chosen to be administered ad the anticoagulant therapy during PCI, co-administer another antocoagulant with factor IIa activity such as UFH.
Don'ts
- Do not administer IV GP IIb/IIIa inhibitors to patients with low risk of ischemic events or at high risk of bleeding and who are already on aspirin and P2Y12 receptor inhibitors therapy.
- Do not administer IV beta-blockers among hemodynamically unstable patients.
- Do not administer a complete dose of prasugrel among patients under 60kg (132lbs) due to high exposure to the active metabolite. They should receive half the dose of prasugrel although there is no evidence that half the dose is as effective as a complete dose.
- Do not administer fibrinolytic therapy to patients with unstable angina.[9]
- Do not administer 2 P2Y12 receptor inhibitors, even in the presence of hypersensitivity or GI interoperability to aspirin.
References
- ↑ 1.0 1.1 1.2 Jneid H, Anderson JL, Wright RS, Adams CD, Bridges CR, Casey DE; et al. (2012). "2012 ACCF/AHA focused update of the guideline for the management of patients with unstable angina/non-ST-elevation myocardial infarction (updating the 2007 guideline and replacing the 2011 focused update): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines". J Am Coll Cardiol. 60 (7): 645–81. doi:10.1016/j.jacc.2012.06.004. PMID 22809746.
- ↑ "http://eurheartj.oxfordjournals.org/content/32/23/2999.full.pdf" (PDF). External link in
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(help) - ↑ "http://eurheartj.oxfordjournals.org/content/32/23/2999.full.pdf" (PDF). External link in
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(help) - ↑ "Therapeutic effects of captopril on ischemia and ... [Am Heart J. 1994] - PubMed - NCBI".
- ↑ "Therapeutic effects of captopril on ischemia and ... [Am Heart J. 1994] - PubMed - NCBI".
- ↑ Kaplan K, Davison R, Parker M, Przybylek J, Teagarden JR, Lesch M (1983). "Intravenous nitroglycerin for the treatment of angina at rest unresponsive to standard nitrate therapy". Am J Cardiol. 51 (5): 694–8. PMID 6402912.
- ↑ Trelle S, Reichenbach S, Wandel S, Hildebrand P, Tschannen B, Villiger PM; et al. (2011). "Cardiovascular safety of non-steroidal anti-inflammatory drugs: network meta-analysis". BMJ. 342: c7086. doi:10.1136/bmj.c7086. PMC 3019238. PMID 21224324. Review in: Evid Based Med. 2011 Oct;16(5):142-3
- ↑ Coxib and traditional NSAID Trialists' (CNT) Collaboration. Bhala N, Emberson J, Merhi A, Abramson S, Arber N; et al. (2013). "Vascular and upper gastrointestinal effects of non-steroidal anti-inflammatory drugs: meta-analyses of individual participant data from randomised trials". Lancet. 382 (9894): 769–79. doi:10.1016/S0140-6736(13)60900-9. PMC 3778977. PMID 23726390. Review in: Ann Intern Med. 2013 Oct 15;159(8):JC12
- ↑ Anderson HV (1995). "Intravenous thrombolysis in refractory unstable angina pectoris". Lancet. 346 (8983): 1113–4. PMID 7475596.