Harrison 21st edition Update on NSTE-ACS

Harrison 21st edition Update on NSTE-ACS

NSTEMI/unstable angina is now called as NSTE-ACS

The highlight of this condition is formation of platelet rich thrombus which is fibrin poor. Hence Fibrinolysis is not indicated in this condition. In contrast STEMI has a fibrin rich thrombus and hence Thrombolysis is indicated.

Clinical features

Chest pain at rest or minimal activity that has following features

  1. Duration of pain at rest > 10 minutes
  2. Recent origin of pain < 2 weeks
  3. Crescendo pattern: more severe and longer lasting as compared to previous episodes experienced by patient
Case based Scenario

75-year-old retired banker who suffers from hypertension and obesity has presented with multiple episodes of chest pain on minimal activity like walking to washroom since last evening. The current episode of chest pain occurred at rest and is associated with diaphoresis and shortness of breath. Past medical history is positive for having undergone angiography in 2020 which showed 50 percent blockage in RCA and posterior descending artery.

On examination: anxious patient with cool extremities and sinus tachycardia is noted. On auscultation S3 and S4 are heard with Basal rales and BP = 90/60 mm Hg

Work up:
  1. ECG shows ST depression of 2mm with T wave inversion in lead V1 to V4.
  2. Serial Cardio biomarker: Cardiac troponin I shows a rise and fall with one value > 99th centile upper reference limit.
  3. TIMI Score to determine mortality in NSTE_ACS and determine need for early PCI. It contains 7 parameters with each parameter given one point. Score between 5 to 7 is called high risk.
    1. Age > 65 years
    2. Know case of CAD with >50 percent stenosis
    3. > 2 episodes in last 24 hours
    4. ST deviation of >0.5 mm in presenting ECG
    5. Elevated biomarkers
    6. Prior angina episodes
    7. >3 CAD risk factor
Treatment of NSTE-ACS: Mnemonic: ATE-MBNS-PCI
  1. Aspirin plus Ticagrelor (Dual antiplatelet therapy)
  2. Enoxaparin
  3. Morphine
  4. Beta blocker: Metoprolol
  5. Nitrates
  6. Statin: high intensity to stabilize atherosclerotic plaques
  7. Shift to PCI equipped center
    Immediate invasive therapy Early invasive therapy Invasive therapy
    PCI within 2 hoursPCI within 24 hoursPCI within 72 hours
    Inclusion criteria
    Cardiogenic shock
    Pain refractory to medical therapy
    Acute heart failure
    Mechanical complications of MI
  8. Drugs used during PCI to prevent peri-procedural MI: Eptifibatide, Tirofiban, Cangrelor
  9. Drugs used after PCI : Apixaban

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