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, and no PDE5i, Nitroglycerin 0.4mg (or 1 spray)  SL q5mins x3, then IV if persistent symptoms

    • Current American Heart Association (AHA) and European Society of Cardiology (ESC) guidelines recommend to avoid nitrates in right ventricular MI due to risk of hypotension (based on limited study with 40 patients that received unknown doses and route of nitroglycerin), but recent meta-analysis (with 1050 patients from two studies) concluded that hypotension secondary to nitrate use in RV MI is not significantly higher than in other territories

    • Consider preparing for hypotension in ALL patients with myocardial infarction, especially when using nitrates which may have an absolute effect of 3 adverse events per 100 treatments

  • *Consider morphine if persistent chest discomfort despite nitrates ando ther antiischemic therapies

  • *If no heart failure/hemodynamic compromise/bradycardia/severe asthma/cocaine, Metoprolol 25mg PO x1

  • 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 reperfusion)

  • 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%)