Acute coronary syndrome management

Include in assessment

• 12 lead ECG (then cardiac monitoring)
• Bloods: usual bloods (FBC, U&Es, LFTs, CRP, glucose) plus high-sensitivity troponin, magnesium, phosphate, lipids
• Chest X-ray (LVF signs, other causes)

High-sensitivity troponin testing

• Value peaks at 12 hours after pain onset but value will be rising before this
• Interval testing is used in non-STEMI patients to look for a significant change for diagnosis of MI (or exclusion in low risk patients with normal ECG)
• It is usually tested at presentation and 3 hours later 
• The definition of ‘significant change’ varies depending on the assay used
• A normal value ≥6 hours post-pain onset rules out MI

Initial ABCDE approach

Follow usual ABCDE approach if critically ill.

Short-term management of ACS

Initial management – MOAN

• Morphine: 10mg in 10ml slow IV – titrate to pain (+ 10mg metoclopramide IV)
• Oxygen: only if saturations below target range
• Aspirin: 300mg PO loading dose (then 75mg OD)
• Nitrates: sublingual GTN if not hypotensive (then PRN)

Other medications 

• Second antiplatelet and anticoagulant: 
  • P2Y₁₂-receptor inhibitor (prasugrel or ticagrelor or clopidogrel) – cardiologist will start during PCI
  • ACS-dose anticoagulation (fondaparinux or unfractionated heparin)
    • in STEMI patients/patients having immediate PCI, cardiologist will start during PCI
    • in NSTEMI patients not having immediate PCI, start before PCI if low bleeding risk
• Early long term medications to consider:
  • β-blocker 
  • ACE-inhibitor (once haemodynamically stable)
  • Statin

Reperfusion therapy (Percutaneous Coronary Intervention – PCI)

• STEMI → immediate PCI (<2h)
• Non-ST elevation ACS
  • Very high-risk (haemodynamically unstable, acute heart failure, arrhythmias, ongoing/recurrent pain/ischaemic changes, mechanical complications) → immediate PCI (<2h)
  • High-risk (rise and fall in troponin compatible with MI, dynamic ischaemic changes, GRACE score >140) → early PCI (<24h)
  • Intermediate-risk (GRACE score >109, diabetes, renal impairment, left ventricular systolic dysfunction, early post-infarction angina, prior PCI/CABG) → PCI (<72h) 
  • Low-risk (none of above features) → non-invasive testing (e.g. stress echocardiography) or PCI (<72h) may be appropriate

Other points

• All patients should have an echocardiogram to assess LV function
• Check electrolytes regularly and ensure patients are on cardiac monitoring while in hospital
• STEMI patients with complete revascularisation may be discharged after 2-3 days; low-risk NSTEMI patients with complete revascularisation may be discharged within 24 hours

Long-term management of ACS

Antiplatelet therapy 

• Patient without AF: aspirin (lifelong) + ticagrelor/prasugrel/clopidogrel (for 1 year)
• Patient with AF: DOAC (lifelong) + clopidogrel (for 1 year) + aspirin (for 1 week)
• Give with PPI if patient is at risk of GI bleeding

NB: durations depend on bleeding and thrombosis risk, and they may modified on a case-by-case basis. 

Cardiovascular risk reduction

• Statin
• BP control
• Lifestyle modifications/cardiac rehabilitation and smoking cessation 

Other treatments 

• β-blocker (lifelong if LV dysfunction; for at least 1 year and consideration of lifelong use if not)
• ACE inhibitor (lifelong)
• Aldosterone antagonist, e.g. eplerenone (if LV dysfunction) 

References: NICE ‘NG185 Acute coronary syndromes’ 2020; European Society of Cardiology ‘Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation’ 2020; European Society of Cardiology ‘Guidelines on Management of Acute Myocardial Infarction in Patients Presenting with ST-Segment Elevation’ 2017

Test your knowledge

Now for some stations!

1. Acute assessment – chest pain
2. STEMI
3. Chest pain history 1
4. Chest pain history 2
5. More here!