Unstable Angina

From Anvita Health Wiki

Contents 1 More Specific Terms 2 Introduction 3 Etiology 4 Pathology 5 Clinical-manifestations 6 Laboratory 7 Diagnostic-procedures 8 Radiology 9 Complications 10 Differential-diagnosis 11 Management 12 More General Terms 13 Additional Terms 14 References

More Specific Terms

• non ST segment elevation acute coronary syndrome (NSTEACS)
• post myocardial infarction (MI) angina

Introduction

• Chest pain of myocardial ischemia that occurs at rest, new onset of pain with exertion, or pain that has accelerated (more frequent, longer in duration, or lower in threshold). Recurrent (especially early morning) angina within the 1st few weeks following myocardial infarction is also considered unstable angina.

Etiology

• rupture or fissuring of atherosclerotic plaques (most common)
• severe anemia
• hypertension
• heart failure
• coronary vasospasm

Pathology

• rupture or fissuring of atherosclerotic plaques results in

• thrombus formation
• increased platelet reactivity
• increased coronary vasomotor tone.

• left ventricular dysfunction, pulmonary edema, transient mitral regurgitation, or hypotension during episodes of ischemia indicates extensive areas of myocardium at risk

Clinical-manifestations

• chest pain in about 2/3 of patients [11]

• women present without chest pain more frequently than men 38& vs 27% [11]

• dyspnea is most common presentations in women, diabetics & elderly
• other features may be present

• congestive heart failure
• pulmonary edema
• hypotension
• mitral regurgitation

• papillary muscle dysfunction
• S3, S4 gallop

Laboratory

• markers of myocardial infarction

Diagnostic-procedures

• electrocardiogram:

• ST segment elevation or ST segment depression *H* > 1 mm in 2 contiguous leads
• T-wave inversion > 2 mm *H*
• new left bundle branch block *H*
• Q waves, old ST segment or T wave abnormalities *I*
• T wave inversion in leads with dominant R waves *L*

• echocardiogram may show regional wall abnormalities
  *H*=high, *I*=intermediate, *L* low risk
  

• No advantage to routine early coronary angiography [9]

Radiology

• CT angiography can rule out acute coronary syndrome [13]

Complications

• 10-20% risk of progression to acute myocardial infarction

• higher risk for progression to acute MI is associated with

• new onset of pain at rest
• a sudden change in anginal pattern
• labile ST-T changes on EKG
• recurrent or persistent pain after initiation of therapy

• women with low risk features may be at increase risk when treated with invasive strategy [3]

Differential-diagnosis

• see chest pain, chest pain syndrome

Management

• see initial management of acute coronary syndrome
• see ST segment elevation acute coronary syndrome & non ST segment elevation acute coronary syndrome
• general

• hospitalization
• bed rest, sedation
• correction of precipitating factors

• hypertension
• anemia - blood transfusion when Hct > 25% helpful [6]
• hypoxia

• goals of treatment

• aggressively relieve ischemic symptoms with anti-anginal drugs
• inhibit thrombosis in susceptible patients

• oxygen:

• 2-4 liters/min by nasal cannula
• do not continue for more than 3 hours unless hypoxia is present

• pharmacologic agents

• antiplatelet agents

• aspirin 162-325 mg PO initially, then QD
• clopidogrel ( Plavix) 75 mg PO QD

• aspirin contraindicated
• use in combination with aspirin 81 mg QD [3] - esomeprazole more effective than famotidine in preventing GI bleed [14]
• unless CABG is likely

• abciximab ( ReoPro)

• may be useful for unstable angina without persistent ST segment elevation [5]
• unless CABG is likely (long 1/2 life)

• ticagrelor ( Brilinta) is more effective clopidogrel with similar bleeding risk [15]

• low-molecular-weight heparin

• except in obesity, renal failure [3]

• nitrates, except with suspected right ventricular MI
• beta blockers ( intravenous esmolol)

• if contraindicated, use verapamil or diltiazem [3]

• spironolactone of uncertain value [3]

• thrombolytic therapy (ST segment elevation)

• streptokinase
• tissue plasminogen activator ( TPA)

• revascularization may be superior to thrombolytic therapy

• percutaneous intervention ( PCI)

• if transfer can be facilitated within 2 hours of hospital arrival [3]
• STEMI, ACS with LBBB, posterior wall MI [3]

• coronary artery bypass graft ( CABG)

• secondary prophylaxis

• HMG CoA reductase inhibitor ( statin)

• start within 24-96 hours [3]
• more intensive LDL cholesterol lowering appears to be associated with better outcomes
• see PROVE-IT, REVERSAL, GRACE studies
• no benefit to adding statin within 14 days [10]

• start chronic cardioselective beta-blocker within 3-21 days ( atenolol, metoprolol) [3]
• ACE inhibitor ( ARB as an alternative)
• eplerenone ( Inspra) for LV dysfunction after MI [3]

More General Terms

• angina
• chest pain

Additional Terms

• stable angina pectoris (chronic stable angina)

References

1. Stedman's Medical Dictionary 26th ed, 27th ed Williams & Wilkins, Baltimore, 1995, 1999
2. Medical Knowledge Self Assessment Program (MKSAP) 11 American College of Physicians, Philadelphia 1998
3. Medical Knowledge Self Assessment Program (MKSAP) 14, 15 American College of Physicians, Philadelphia 2006, 2009
4. Journal Watch 24(9):69-70, 2004
   - Nissen SE, Tuzcu EM, Schoenhagen P, Brown BG, Ganz P, Vogel RA, Crowe T, Howard G, Cooper CJ, Brodie B, Grines CL, DeMaria AN; REVERSAL Investigators. Effect of intensive compared with moderate lipid-lowering therapy on progression of coronary atherosclerosis: a randomized controlled trial. JAMA. 2004 Mar 3;291(9):1071-80. PMID: [1]
   - Cannon CP, Braunwald E, McCabe CH, Rader DJ, Rouleau JL, Belder R, Joyal SV, Hill KA, Pfeffer MA, Skene AM; Pravastatin or Atorvastatin Evaluation and Infection Therapy- Thrombolysis in Myocardial Infarction 22 Investigators. Intensive versus moderate lipid lowering with statins after acute coronary syndromes. N Engl J Med. 2004 Apr 8;350(15):1495-504. Epub 2004 Mar 08. PMID: [2]
5. Journal Watch 22(6):47, 2002 Journal Watch 22(6):47, 2002 Boersma E, Harrington RA, Moliterno DJ, White H, Theroux P, Van de Werf F, de Torbal A, Armstrong PW, Wallentin LC, Wilcox RG, Simes J, Califf RM, Topol EJ, Simoons ML. Platelet glycoprotein IIb/IIIa inhibitors in acute coronary syndromes: a meta-analysis of all major randomised clinical trials. Lancet. 2002 Jan 19;359(9302):189-98. Erratum in: Lancet 2002 Jun 15;359(9323):2120. PMID: [3]
6. Journal Watch 24(21):158, 2004 Rao SV, Jollis JG, Harrington RA, Granger CB, Newby LK, Armstrong PW, Moliterno DJ, Lindblad L, Pieper K, Topol EJ, Stamler JS, Califf RM. Relationship of blood transfusion and clinical outcomes in patients with acute coronary syndromes. JAMA. 2004 Oct 6;292(13):1555-62. PMID: [4]
7. Mehta SR et al, Routine vs Selective Invasive Strategies in Patients with Acute Coronary Syndromes. A Collaborative Meta-analysis of Randomized Trials. JAMA 293(33), 2908, 2005
8. Gibler WB, Cannon CP, Blomkalns AL, Char DM, Drew BJ, Hollander JE, Jaffe AS, Jesse RL, Newby LK, Ohman EM, Peterson ED, Pollack CV; American Heart Association Council on Clinical Cardiology; American Heart Association Council on Cardiovascular Nursing; Quality of Care and Outcomes Research Interdisciplinary Working Group; Society of Chest Pain Centers. Practical implementation of the Guidelines for Unstable Angina/ Non-ST-Segment Elevation Myocardial Infarction in the emergency department. Ann Emerg Med. 2005 Aug;46(2):185-97. <PubMed> PMID: [5] <Internet> [6]
9. de Winter RJ, Windhausen F, Cornel JH, Dunselman PH, Janus CL, Bendermacher PE, Michels HR, Sanders GT, Tijssen JG, Verheugt FW; Invasive versus Conservative Treatment in Unstable Coronary Syndromes (ICTUS) Investigators. Early invasive versus selectively invasive management for acute coronary syndromes. N Engl J Med 2005 Sep 15; 353:1095-104. PMID: [7]
   - Boden WE. Acute coronary syndromes without ST-segment elevation - What is the role of early intervention? N Engl J Med 2005 Sep 15; 353:1159-61
10. Briel M, Schwartz GG, Thompson PL, de Lemos JA, Blazing MA, van Es GA, Kayikcioglu M, Arntz HR, den Hartog FR, Veeger NJ, Colivicchi F, Dupuis J, Okazaki S, Wright RS, Bucher HC, Nordmann AJ. Effects of early treatment with statins on short-term clinical outcomes in acute coronary syndromes: a meta-analysis of randomized controlled trials. JAMA. 2006 May 3;295(17):2046-56. PMID: [8]
11. Canto JG et al, Symptom presentation of women with acute coronary syndromes: Myth vs reality. Arch Intern Med 2007, 167:2405 PMID: [9]
    - Dracup K The challenge of women and heart disease. Arch Intern Med 2007, 167:2396 PMID: [10]
12. Wright SR et al 2011 ACCF/AHA Focused Update of the Guidelines for the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction (Updating the 2007 Guideline) J Am Coll Cardiol, (Published online 28 March 2011) <PubMed> PMID: [11] <Internet> [12]
13. Litt HI et al CT Angiography for Safe Discharge of Patients with Possible Acute Coronary Syndromes N Engl J Med, March 26, 2012 <PubMed> PMID: [13] <Internet> [14]
14. Ng F-H et al. Esomeprazole compared with famotidine in the prevention of upper gastrointestinal bleeding in patients with acute coronary syndrome or myocardial infarction. Am J Gastroenterol 2012 Mar; 107:389. PMID: [15]
15. Prescriber's Letter 19(5): 2012 COMMENTARY: Antiplatelets After Acute Coronary Syndrome or Coronary Stent CHART: Comparison of Oral Antithrombotics Detail-Document#: [16] (subscription needed) [17]
16. National Guideline Clearinghouse ACC/AHA 2007 guidelines for the management of patients with unstable angina/non ST-Elevation myocardial infarction. ngc-guideline: [18]
    - Acute coronary syndromes: 2005 International Consensus Conference on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. American Heart Association ngc-guideline: [19]
    - Unstable angina pectoris. (Finnish Medical Society Duodecim) ngc-guideline: [20]
    - Acute coronary syndromes: unstable angina pectoris and non-ST segment elevation myocardial infarction (NSTEMI) Finnish Medical Society Duodecim ngc-guideline: [21]
    - Diagnosis and treatment of chest pain and acute coronary syndrome (ACS). (ICSI) ngc-guideline: [22]
    - Guidance on the use of glycoprotein IIb/IIIa inhibitors in the treatment of acute coronary syndromes. National Institute for Health and Clinical Excellence ngc-guideline: [23]
    - Acute coronary syndromes. A national clinical guideline. Scottish Intercollegiate Guidelines Network ngc-guideline: [24]
    - Guidelines for the management of acute coronary syndromes 2006. National Heart Foundation of Australia (1) Guidelines for the management of acute coronary syndromes 2006. (2) 2007 addendum to the National Heart Foundation of Australia/ Cardiac Society of Australia and New Zealand guidelines for the management of acute coronary syndromes 2006. ngc-guideline: [25]
    - National Academy of Clinical Biochemistry and IFCC Committee for standardization of markers of cardiac damage laboratory medicine practice guidelines: Analytical issues for biochemical markers of acute coronary syndromes. ngc-guideline: [26]
    - National Academy of Clinical Biochemistry laboratory medicine practice guidelines: Clinical characteristics and utilization of biochemical markers in acute coronary syndromes. ngc-guideline: [27]
    - National Academy of Clinical Biochemistry laboratory medicine practice guidelines: Point of care testing, oversight and administration of cardiac biomarkers for acute coronary syndromes. ngc-guideline: [28]
    - Unstable angina and NSTEMI: the early management of unstable angina and non-ST-segment-elevation myocardial infarction. National Clinical Guideline Centre for Acute and Chronic Conditions ngc-guideline: [29]
    - Acute coronary syndrome and myocardial infarction. (Finnish Medical Society Duodecim) ngc-guideline: [30]

unstable angina (acute coronary syndrome, ACS)