Table of Contents
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
What are the definitions of STEMI, NSTEMI and unstable angina
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What are the three patterns of unstable angina?
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In which ECG leads would ST changes be present in for each of the following myocardial infarctions? Which coronary artery would be involved for each?
1. Inferior
2. Anteroseptal
3. Anterolateral
4. Lateral
5. Posterior
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What is the GRACE score and which factors does it take into account?
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