Unstable angina/ NSTEMI resident survival guide
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.
Ischemia-guided Strategy vs. Invasive Strategy
Shown below is a table that lists the factors that are associated with appropriate selection of invasive strategy vs. ischemia-guided strategy among patients with NSTE-ACS.[1]
Strategy | Subcategory | Clinical Findings |
Invasive | Immediate invasive (within 2 hours) | ❑ Refractory angina |
❑ Signs or symptoms of either heart failure or new/worsening mitral regurgitation | ||
❑ Hemodynamic instability | ||
❑ Recurrent angina or ischemia at rest or with low-level activities despite intensive pharmacologic therapy | ||
Early invasive (within 24 hours) | ❑ None of the requirements for immediate invasive strategy were met | |
❑ GRACE risk score > 140 | ||
❑ Temporal changes in troponin level | ||
❑ New/presumably new ST-segment depression | ||
Delayed invasive (within 25-72 hours) | ❑ None of the requirements for immediate/early invasive strategies was met | |
❑ Known history of diabetes mellitus | ||
❑ Known history of renal insufficiency (defined as eGFR < 60 ml/min/1.73 m2) | ||
❑ Reduced LV systolic function (LVEF < 40%) | ||
❑ Early post-infarct angina | ||
❑ PCI within 6 months | ||
❑ History of prior CABG | ||
❑ GRACE risk score 109-140 or TIMI risk score ≥ 2 | ||
Ischemia-guided strategy | ❑ None of the requirements for any of the invasive (either immediate, early, or delayed) strategies was met | |
❑ Low-risk score (either GRACE risk score < 190 or TIMI risk score = 0-1) | ||
❑ Low-risk Troponin-negative female patients | ||
❑ Patient or clinician preference in the absence of high-risk features |
Adapted from Amsterdam et al. 2014 AHA/ACC Guideline for the Management of Patients with Non-ST-Elevation Acute Coronary Syndromes. J Am Coll Cardiol. 2014;64(24):e139-e228[1]
FIRE: Focused Initial Rapid Evaluation
A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention. The following algorithm is derived from the 2014 AHA/ACC guideline for the management of patients with Non-ST-elevation acute coronary syndromes (either unstable angina or non-ST-elevation myocardial infarction).[1]
Boxes in the red color signify that an urgent management is needed.
Identify cardinal findings of unstable angina/ NSTEMI : ❑ Chest pain or chest discomfort
❑ Perform a thorough cardiovascular physical examination and search for signs of myocardial ischemia, signs of HF, and signs of other non-ischemic causes of the patient's symptoms that might suggestive alternative diagnoses:
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Perform diagnostic tests ❑ Perform ECG within 10 minutes of patient arrival to the ED (LOE: IC)
❑ Consider supplemental ECG leads V7 to V9 in patients whose initial ECG is non-diagnostic and who are at intermediate/high risk of ACS (LOE: IIB)
❑ Biomarkers of heart failure
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Rule out alternative life threatening diseases ❑ Aortic dissection (classical findings: vomiting, subcutaneous emphysema) | |||||||||||||||||||||||||||
Assess the Patient's Prognosis ❑ Apply ANY one of the following risk scores to evaluate the patient's prognosis (LOE: IA)
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Does the patient have any of the following (at least one is sufficient to determine that the patient has high-risk features)?
❑ High risk score (defined as either TIMI > 1 OR GRACE score > 109) ❑ Signs or symptoms of HF or new/worsening mitral regurgitation ❑ Hemodynamic instability ❑ Sustained VT or VF ❑ New or presumably new ST-segment depression ❑ Known history of diabetes mellitus ❑ Known history of renal insufficiency (defined as eGFR < 60 min/min/1.72 m2) ❑ Reduced LV systolic function (LVEF < 40%) ❑ Recent PCI within 6 months | |||||||||||||||||||||||||||
No. The patient does NOT have ANY of the above high risk features. | Yes. The patient has at least one of the above high risk features | ||||||||||||||||||||||||||
Follow an ischemia-guided strategy ❑ Administer dual antiplatelet therapy to all patients with NSTE ACS (aspirin plus only one P2Y12)
❑ Titrate oxygen via nasal cannula to SpO2 > 90% for patients with saturation <90%, respiratory distress, or other high-risk features of hypoxemia (LOE: IC)
❑ Administer nitroglycerin
Contraindicated in suspected right ventricular MI, recent use of phosphodiesterase inhibitors (24 hours of sildenafil or vardenafil use or 48 hours of tadalafil use), decreased blood pressure 30 mmHg below baseline
❑ Consider PO non-dihydropyridine CCB (either verapamil or diltiazem) only if patients either cannot tolerate beta blockers, are allergic to beta blockers, or were administered beta blockers plus nitrates and have recurrent ischemia (LOE: IIC)
❑ Administer IV morphine if persistent symptoms (LOE: IIB) or pulmonary edema
❑ Administer ANY of the following high-intensity statins to patients who have co contraindications to statin therapy (LOE: IA)
❑ Administer ANY of the following anticoagulation therapies for all patients regardless of initial treatment strategy
| Follow an invasive strategy ❑ Administer dual antiplatelet therapy to all patients with NSTE ACS (aspirin plus only one P2Y12)
❑ Titrate oxygen via nasal cannula to SpO2 > 90% for patients with saturation <90%, respiratory distress, or other high-risk features of hypoxemia (LOE: IC)
❑ Administer nitroglycerin
Contraindicated in suspected right ventricular MI, recent use of phosphodiesterase inhibitors (24 hours of sildenafil or vardenafil use or 48 hours of tadalafil use), decreased blood pressure 30 mmHg below baseline
❑ Consider PO non-dihydropyridine CCB (either verapamil or diltiazem) only if patients either cannot tolerate beta blockers, are allergic to beta blockers, or were administered beta blockers plus nitrates and have recurrent ischemia (LOE: IIC)
❑ Administer IV morphine if persistent symptoms (LOE: IIB) or pulmonary edema
❑ Administer ANY of the following high-intensity statins to patients who have co contraindications to statin therapy (LOE: IA)
❑ Administer ANY of the following anticoagulation therapies for all patients regardless of initial treatment strategy
❑ Consider administration of GP IIb/IIIa in addition to dual antiplatelet therapy in high-risk (e.g. troponin positive) patients (LOE: IIB)
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Does the patient meet ANY of the following findings to transfer to invasive strategy?
❑ Refractory angina, OR ❑ Angina at rest or with minimal activity, OR ❑ Objective evidence of ischemia (dynamic ECG changes or myocardial perfusion defect) by non-invasive testing, OR ❑ Presence of high prognostic risk (high TIMI or high GRACE score) | |||||||||||||||||||||||||||
No. The patient does not have any of the above findings. The patient will continue to be managed according the the ischemia-guided strategy | Yes. The patient has at least of the above findings and will be transferred to the invasive strategy for revasculization | ||||||||||||||||||||||||||
Perform Risk Stratification Before Discharge for Patients Who had an ischemia-guided strategy of NSTE-ACS ❑ Perform ANY of the following non-invasive testing among low/intermediate risk patients who have had no ischemia symptoms at rest/low-level activity for the past 12-24 hours (LOE: B):❑ Perform treadmill exercise testing (only if ECG is free of resting ECG changes that might alter the interpretation of the ECG results (LOE: IC) ), OR:❑ Perform Stress testing with imaging modality (if patients have resting ECG changes that might alter the interpretation of the ECG results (LOE: IB) ), OR
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Proceed to pre-discharge care | Proceed to revascularization therapy | ||||||||||||||||||||||||||
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.[2]
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 | |||||||||
Revascularization Therapy
Confirmed NSTE ACS (either unstable angina or NSTEMI) | |||||||||||||||||||||||||||||||
Ischemia-guided strategy | Early invasive strategy | ||||||||||||||||||||||||||||||
Was pharmacologic therapy for ischemia-guided strategy effective?
If the patient has ANY of the following findings, pharmacologic therapy is considered ineffective: | |||||||||||||||||||||||||||||||
Yes. Pharmacologic therapy was effective | No. Pharmacologic therapy was not effective | ||||||||||||||||||||||||||||||
Proceed to pre-discharge care | Revascularization. Use SYNTAX score to determine if patient will undergo PCI or CABG | ||||||||||||||||||||||||||||||
PCI with stenting | CABG | ||||||||||||||||||||||||||||||
Continue the following drugs ❑ Administer/Continue non-enteric coated aspirin PO 81-325 mg before PCI (LOE: IA)
❑ Continue anticoagulant (either UFH (LOE: IB), enoxaparin (LOE: IA), or fondaparinux (LOE: IB)). To view the dose of each anticoagulant during PCI, click here
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Continue the following drugs ❑ Continue aspirin (LOE: IA) | |||||||||||||||||||||||||||||||
Discontinue the following drugs
❑ Discontinue P2Y12 inhibitor (either clopidogrel or ticagrelor) 5 days before elective CABG / up to 24 hours in case of urgent CABG (LOE: IB) ❑ Discontinue prasugrel 7 days before elective CABG / before 7 days in case of urgent CABG ❑ Discontinue eptifibatide/tirofiban at least 2-4 hours before CABG (LOE: IB) | |||||||||||||||||||||||||||||||
Proceed to pre-discharge care | |||||||||||||||||||||||||||||||
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
❑ Counsel the patient on lifestyle change and signs/symptoms of myocardial ischemia and MI, including presenting to ED for suggestive symptoms > 3-5 minutes ❑ Refer patient to comprehensive cardiovascular rehabilitation program Dual Antiplatelet Therapy
❑ Administer ANY of the following antiplatelet agents in addition to aspirin
Continue ANY of clopidogrel, ticagrelor, or prasugrel up to 12 months for patients without PCI and for at least 12 months for patients with stent (either bare metal stent (BMS) or drug-eluting stent (DES) ). Early discontinuation or prolonged use of non-aspirin antiplatelet agents is reasonable based on patient risk of bleeding ❑ Administer 1 dose of sublingual or spray nitroglycerin to all patients post-NSTE ACS with angina lasting more than 1 minute. Prescribe nitroglycerin with verbal and written instruction for its administration (LOE: IC) Statin ❑ Administer ANY of the following high-intensity statins indefinitely post-NSTE ACS
Beta blockers
Non-dihydropyridine calcium channel blockers in select patients
ACE inhibitors or ARBs ❑ Administer ACE inhibitors indefinitely to patients with LVEF < 40% and among patients with HTN, diabetes, or stable CKD unless contraindicated (LOE: IA) ❑ If ACEI cannot be tolerated, administer ARB to patients with HF or MI with LVEF < 40% (LOE: IA) Aldosterone blocker
❑ Administer ANY aldosterone blocker to patients post-MI receiving therapeutic doses of ACEI and beta blockers with either LVEF <40%, diabetes, or HF (LOE: IA). Aldosterone blockers are contraindicated in significant renal insufficiency (defined as serum Cr > 2.5 mg/dL in men or > 2 mg/dL in women) or hyperkalemia (K > 5 mEq/L).
Administer vaccinations Perform Risk Stratification Before Discharge for Patients Who had an ischemia-guided strategy of NSTE-ACS
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Dosing of Parenteral Anticoagulants During PCI
Anticoagulant | Patients who have received prior anticoagulant therapy | Patients who have NOT received prior anticoagulant therapy |
Enoxaparin |
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0.5 mg/kg–0.75 mg/kg IV loading dose |
Bivalirudin |
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0.75 mg/kg loading dose, 1.75 mg/kg/h IV infusion |
Fondaparinux |
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N/A |
UFH |
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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.[5]
- 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 fondaparinux as the sola anticoagulant to support PCI in patients with NSTE ACS due to increased risk of catheter thrombosis.
- Do not administer anticoagulation therapy following PCI unless there is compelling reason to continue such therapy.
- 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 NSAIDs to patients post-NSTE ACS. Attempt managing musculoskeletal pains using either acetaminophen, non-acetylated salicylates, tramadol, or small doses of narcotics before considering NSAIDs (first consider non-selective NSAIDs then selective NSAIDs)
- Do not administer hormone therapy (estrogen with out without progestin) to patients for secondary prevention of coronary events in post-menopausal women.
- Do not administer vitamin supplements (e.g. vitamin E, C, beta-carotene, folic acid, or vitamin B6/B12) for secondary prevention of NSTE ACS.
- Do not administer prasugrel to patients with prior history of strokes or TIA.
- 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.[8]
- 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 Amsterdam EA, Wenger NK, Brindis RG, Casey DE, Ganiats TG, Holmes DR; et al. (2014). "2014 AHA/ACC Guideline for the Management of Patients with Non-ST-Elevation Acute Coronary Syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines". J Am Coll Cardiol. 64 (24): e139–228. doi:10.1016/j.jacc.2014.09.017. PMID 25260718.
- ↑ 2.0 2.1 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) - ↑ 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.