Unstable Angina and Non-ST elevation Myocardial Infarction

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Unstable Angina and Non-ST elevation Myocardial
Infarction

• John Blair, MD

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Unstable Angina / Non ST-Elevation Myocardial
Infarction (UA/NSTEMI)

• Pathophysiology
• Diagnosis
• Initial Therapy
• Risk-Stratification
• Invasive vs Conservative
• Post AMI Care

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UA / NSTEMI

• Pathophysiology
• Diagnosis
• Initial Therapy
• Risk-Stratification
• Invasive vs Conservative
• Post AMI Care

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Sudden Thrombus or Thromboembolism
Superficial Erosion
Ruptured Fibrous Cap
Modified from Libby PCirc 104365,2001
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(No Transcript)
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Causes of UA/NSTEMI

• Thrombus or thromboembolism, usually arising on
  disrupted or eroded plaque Most Common Cause.
• Dynamic obstruction coronary spasm or
  vasoconstriction
• Progressive mechanical obstruction to coronary
  flow ie restenosis after PCI
• Coronary arterial inflammation
• Coronary artery dissection
• Secondary UA Increasing oxygen demands in the
  setting of a fixed lesion.

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Acute Coronary Syndromes

• Pathophysiology
• Diagnosis
• Initial Therapy
• Risk-Stratification
• Invasive vs Conservative
• Post AMI Care

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Likelihood that Signs and Symptoms Represent ACS
Braunwald E, Mark DB, Jones RH NHLBI Unstable
Angina 1994
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Algorithm for Evaluation and Management of
Patients Suspected of Having ACS
Anderson, J. L. et al. J Am Coll Cardiol
200750e1-e157
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Timing of Release of Various Biomarkers After
Acute Myocardial Infarction
Anderson, J. L. et al. J Am Coll Cardiol
200750e1-e157
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Acute Coronary Syndromes

• Pathophysiology
• Diagnosis
• Initial Therapy
• Risk-Stratification
• Invasive vs Conservative
• Post AMI Care

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Treatment

• Increases oxygen supply to ischemic tissue
• Start at 4L/min
• Use caution in COPD patients

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

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Treatment

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

• Blocks formation of thromboxane A2 and thus
  prevents platelet aggregation
• Reduces mortality, reinfarction, and stroke in
  patients with MIs

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Treatment

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

• Blocks catecholamines from binding to
  ß-adrenergic receptors
• Reduces myocardial demand by reducing HR, BP,
  contractility
• Decreases incidence of primary VF

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Treatment

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

• Dilates coronary arteries
• Increases venous dilation and therefore
  decreases venous return
• Decreases myocardial demand by decreasing preload

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Treatment

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

• Reduces pain of ischemia and anxiety ? indirect
  effect on catecholamines
• May dilate coronary arteries and reduce preload
  ? decreases myocardial oxygen demand

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Treatment

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

• Heparins - Indirect thrombin inhibitors
  including LMWH
• DTI - Direct thrombin inhibitors
• Reduce further coagulation

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Treatment

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

• Blocks platelet receptor so platelets cannot
  bind fibrinogen and form clots
• caution in renal disease (tirofiban,
  ebtifbatide) and with thrombocytopenia (abciximab)

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Treatment

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

• Blocks the ADP receptor on platelets which also
  prevents fibrinogen binding and clot formation
• Bleeding risks during CABG have limited its
  immediate use until coronary anatomy defined

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Treatment

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

• reduces peripheral vasoconstriction and blood
  pressure
• Alters post-MI LV remodeling

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Treatment

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

• reduces fibrosis, hypokalemia, and arrhythmias
• beneficial in high-risk post-AMI LV dysfunction

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Treatment

• Oxygen
• Aspirin
• Beta-blocker
• Nitroglycerin
• Morphine
• Heparins, DTIs
• IIb/IIIa inhibitors
• Plavix
• ACE/ARB
• Aldosterone Blockade
• Statins

• reduce LDL
• may decrease inflammation

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Initial Therapy

• Anti-ischemic and Analgesic therapy
• Anti-platelet therapy
• Anti-coagulant therapy

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ACC/AHA Guidelines Updated in 2007 from 2002
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Anti-ischemic and Analgesic Therapy

• Bed/chair rest Class I, C
• O2 for SaO2 lt 90, respiratory distress, or
  hypoxemia Class I, B
• NTG 0.4 mg sl q 5 min x 3 doses, then gtt for
  ongoing ischemic discomfort Class I, C
• NTG iv within 48h for persistent ischemia, HF, or
  HTN. Should not preclude use of BB Class I, B
• Oral BB therapy within 24h without 1) HF, 2) low
  output, 3) risk of shock, 4) relative
  contraindications Class I, B

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Anti-ischemic and Analgesic Therapy

• CCB (nondihydropyridine) if contraindication for
  BB in the absence of contraindications Class I,
  B
• ACE inhibitor for LVEF lt0.40 and no hypotension
  (SBP lt100 or lt30 below baseline) Class I, A
• ARB if intolerant to ACE inhibitor Class I, A
• NSAIDS should be discontinued Class I, C

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Anti-Platelet Therapy

• ASA started immediately and continued
  indefinitely Class I, A
• Plavix loading dose (300-600mg) plus
  maintenance 75 mg if ASA intolerant Class I, A
• If h/o GIB, PPI plus anti-platelet therapy
  Class I, B
• GP IIB/IIIA therapy depends on strategy chosen
  (more on this later)
• Risk/benefit to higher loading dose regimens is
  yet to be determined

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Anti-Coagulant Therapy

• Anticoagulant Therapy should be added to
  antiplatelet therapy as soon as possible after
  presentation
• Choice of anticoagulant depends on the strategy
  chosen (more on this later)

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There is an Incremental Benefit to ASA, UFH/LMWH,
and GPIIb/IIIa Therapy
Anderson, J. L. et al. J Am Coll Cardiol
200750e1-e157
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Acute Coronary Syndromes

• Pathophysiology
• Diagnosis
• Initial Therapy
• Risk-Stratification
• Invasive vs Conservative
• Post AMI Care

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Kaplan-Meier Estimates of Probability of Death
Based on Admission Electrocardiogram
Savonitto S, Ardissino D, Granger CB, et al. JAMA
199928170713 (127)
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Troponin I Levels to Predict the Risk of
Mortality in Acute Coronary Syndromes
Antman EM, Tanasijevic MJ, Thompson B, et al. N
Engl J Med 199633513429 (201)
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TIMI Risk Score Cardiac Events by 14 Days(TIMI
11B, ESSENCE)
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GRACE Prediction Score All-cause Mortality
Within 6 Months of Discharge
Eagle KA, Lim MJ, Dabbous OH, et al. JAMA
20042912727-33(168)
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What is Elevated Risk?
Anderson, J. L. et al. J Am Coll Cardiol
200750e1-e157
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Acute Coronary Syndromes

• Pathophysiology
• Diagnosis
• Initial Therapy
• Risk-Stratification
• Invasive vs Conservative
• Post AMI Care

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Choose A Strategy

• Initial Conservative Angiography only if
  patient fails medical management (refractory or
  resting angina) or has objective evidence of
  ischemia (stress testing)
• Initial Invasive Angiography before failure of
  medical management or stress testing
• Immediate angiography (ISAR-COOL) or
• Deferred Angiography (all other trials 12-48h)

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Choose A Strategy - Rationale

• Initial Conservative
• Early trials demonstrate similar efficacy (TIMI
  IIIB, MATE, VANQWISH, RITA-2)
• Aggressive antiplatelet and anticoagulant therapy
  has reduced events
• Initial Invasive
• Rapidly identify the 10-20 with nonocclusive CAD
  and the 20 with 3v CAD

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Less Events in Early Invasive Strategy
Anderson, J. L. et al. J Am Coll Cardiol
200750e1-e157
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Choose A Strategy Guidelines

• Initial invasive
• Refractory angina or hemodynamic/electrical
  instability (Class I, B)
• Initially stabilized patients without
  contraindications and with elevated risk for
  events (Class I, A)
• Initial Conservative
• May be considered in patients with elevated risk
  (Class IIb,B)
• May consider physician or patient preference
  (Class IIb,C)
• Women with low-risk features (Class I, B)

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Anticoagulants and Antiplatelets Initial
Invasive Strategy
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Anticoagulants and Antiplatelets Initial
Conservative Strategy
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Important Points in Hospital Care

• Stress test before discharge for assessment of
  ischemia in initial conservative strategy. Must
  be free of resting ischemia or HF for 12-24h
  Class I, C
• If not classified as low risk, angiography should
  be performed Class I, A
• Fasting lipid panel within 24 hours Class I, C
• Statin regardless of baseline LDL-C pre-discharge
• Echo or MUGA must be done if no plan for left
  ventriculography by angiogram Class I, B

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Acute Coronary Syndromes

• Pathophysiology
• Diagnosis
• Triage
• Initial Therapy
• Invasive vs Conservative
• Post AMI Care

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Post-AMI Care

• Similar to care after STEMI
• Focus on secondary prevention of coronary events
• ASA
• Statin
• BB
• BP control
• Smoking Cessation
• Healthy Lifestyle
• And treatment of LV systolic Dysfunction (EFlt40)
• ACE inhibitor
• ARB if ACE inhibitor intolerant
• Eplerenone if HF or DM, and eGFR gt 30, and K lt 5

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When to Stop Plavix
Anderson, J. L. et al. J Am Coll Cardiol
200750e1-e157
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Thank You