Acute Coronary Syndrome

Definitions

• Suspect ACS in these three presentations
  • Rest angina, which is usually more than 20 minutes in duration
  • New onset angina that markedly limits physical activity
  • Increasing angina that is more frequent, longer in duration, or occurs with less exertion than previous angina
• Subtypes of ACS
  • STEMI
  • NSTE-ACS
    • NSTEMI
      • Elevated troponin in absence of ST elevation
    • Unstable Angina (<4% ACS have normal biomarkers and EKG)
      • New onset angina should be considered as unstable

Types of MI

• 1 = Spontaneous plaque rupture and thrombus
• 2 = Ischemic imbalance
• 3 = Sudden death (biomarkers unavailable)
• 4 = PCI/stent-related
• 5 = CABG-related

History

• Increase risk
  • Radiation to both arms > right arm > left arm
  • Diaphoresis
  • Vomiting
  • Worse on Exertion
• Decrease risk (Note: 7% of patients will have pleuritic chest pain and chest pain reproduced on palpation -> Atypical is common!)
  • Reproduced on chest wall palpation (tenderness)
  • Pleuritic pain
  • Sharp/stabbing
  • Positional
• Onset of pain
• Contraindications to
  • Thrombolysis (see bottom of page)
  • Anticoagulation (eg. currently on anticoagulation)
  • Nitroglycerin (eg. PDE5-i, eg. Viagra)
  • Metoprolol (eg. cocaine)
• Allergy to medications (eg. Aspirin)

Management

• ABC
• Vitals
• Cardiac/oxygen monitor and IV x2
• Oxygen for sat >90%
• Focused history (AMPLE), include above
• Focused physical exam
  • Rule out cardiogenic shock (hypotension, poor perfusion)
  • Rule out heart failure (S3/S4, edema, distended liver)
• 12-lead ECG (repeat if non-diagnostic)
• Consider CXR (r/o pneumothorax, pneumonia, aortic dissection, esophageal rupture)
• Initial Troponin with repeat (3h for highly sensitive assay or 6h for sensitive assay from onset of chest pain)
  • Only 1 Troponin needed if isolated CP >12hrs prior to ED visit and are symptom free for 12hrs prior to their ED visit
• Emergent cardiogenic consultation if shock, heart failure, sustained V Tach
• Aspirin (non-EC) 325mg PO chew or by rectum if unable to take PO
• Labs: CBC, Trop, Chem 10 (K, Mg), INR
• If stable
  • *If chest pain, no hemodynamic compromise (RV infarct), and no PDE5i, Nitroglycerin 0.4mg (or 1 spray) SL q5mins x3
  • *If no heart failure/hemodynamic compromise/bradycardia/severe asthma/cocaine, Metoprolol 25mg PO
  • Consider Fentanyl 25mcg IV or Morphine 2.5mg IV q5 mins (for severe pain, avoid if possible)
• Atorvastatin 80mg PO daily

EKG

• Compare with previous
• If suspicious, consider Serial EKG q10-15mins and URGENT formal echocardiography by cardiologist (r/o wall motion abnormalities suggestive of MI)
• STEMI (or equivalent need for urgent repurfusion)
  • ST segment elevations at J point in 2 contiguous leads >1mm in all leads except V2 and V3
    • Men <40yo, ≥2.5 mm in V2 and V3
    • Men >40yo, ≥2 mm in leads V2 and V3
    • Women ≥ 1.5 mm ST elevation in V2 and V3
• Non-STEMI
  • ST segment depressions or deep T wave inversions without Q waves or no ECG changes
• Unstable Angina
  • No EKG changes

Risk of Treatment

• CRUSADE risk of bleeding post-MI
  • Consider less invasive treatment in STEMI/NSTEMI with high risk of bleeding

STEMI or Equivalent

• Reperfusion + Dual antiplatelet + Anticoagulant
  • Primary PCI (within 90 mins of medical contact) + Ticagrelor 180mg + UFH 50-70 units/kg IV (max 5000 units)
    • If PCI unavailable, <120mins of first medical contact, <12h symptom onset (unless ongoing symptoms), no contraindications (see at bottom of page)
      • Fibrinolysis (goal 30mins) + Clopidogrel 300mg (75mg if age ≥ 75) + anticoagulation [Enoxaparin 30mg IV (adjust for renal and age ≥ 75) or UFH (if possible PCI later)]
• If no reperfusion indicated >12h onset of symptoms for Fibrinolysis or >24h for PCI, start Ticagrelor 180mg + Enoxaparin or UFH
• Glycoprotein IIb/IIIa Inhibitors [eg. Abciximab (Reopro), Eptifibatide (Integrilin), Tirofiban (Aggrastat)] may be given in high risk patients or continued ischemia as determined by the treating cardiologist

NSTEMI or Unstable Angina

• Consider dual antiplatelet (Ticagrelor 180mg) + anticoagulant (enoxaparin or heparin if possible PCI later) for confirmed ACS with high risk of recurrent ischemia
• Consider PCI +/- GP IIb/IIIa inhibitor, especially in evidence of persistent ischemia (pain or EKG changes)
• No evidence for fibrinolysis

Low Risk (unlikely ACS)

• Consider early discharge if negative EKG, troponin and low-risk ACS
  • Marburg Heart Score
  • GRACE Calculator
  • Emergency Department Assessment of Chest Pain Score (EDACS)
  • Vancouver Chest Pain Rule
  • HEART score / HEART pathway

Post-MI

• Lifestyle changes
  • Modifiable risk factors (DLP, HTN, DM)
  • Stop smoking
  • Weight management
  • Physical activity (Consider rehab)
• Medications
  • ASA 81mg (or Clopidogrel 75mg if ASA intolerance)
    • May consider dual antiplatelet therapy in subset (stent)
    • May consider low-dose rivaroxaban 2.5mg PO BID with aspirin in very high risk CV events with low risk bleeding
  • High-intensity Statin (eg. Rosuvastin 20-40mg daily, Atorvastatin 80mg daily)
  • ACEI (or ARB), especially if anterior MI, heart failure or LVEF ≤40%
  • Beta-blocker, especially if heart failure or LVEF ≤40%
    • Consider switch to longer-acting (eg. Bisoprolol 2.5-20mg PO daily to maintain HR<70 and sBP>90mmHg)
• Monitor for post-MI complications
  • Pericarditis (10%)+/- pericardial effusion
    • Suspect in pleuritic chest pain, fever, leukocytosis
    • Aspirin or colchicine
    • If >4w (Dressler's Syndrome) consider NSAIDs and/or corticosteroids
  • LV free wall rupture (3%)
  • VSD (1-2%)
  • Papillary muscle rupture (1%)