2. Acute Coronary Syndromes (ACS)

Definition

ACS is an umbrella term for conditions caused by acute myocardial ischaemia due to coronary artery atherosclerosis and thrombosis:

  • STEMI – ST-Elevation Myocardial Infarction

  • NSTEMI – Non-ST-Elevation Myocardial Infarction

  • Unstable Angina

Pathophysiology

  • Rupture of an atherosclerotic plaque → platelet aggregation and thrombus formation

  • Partial or complete occlusion of coronary artery

  • ↓ Blood flow → myocardial ischaemia ± infarction

Modifiable Risk Factors

Mnemonic: SHODDD

  • Smoking

  • HTN

  • Obesity

  • Diabetes

  • Dyslipidaemia (↑TC, ↑LDL, ↑TC:HDL)

  • Drinking (excess alcohol)

Non-Modifiable Risk Factors

  • Age ↑

  • Male sex

  • South Asian ethnicity

  • Family history: MI <55 in men, <65 in women

  • Personal history of MI, stroke, PVD

Symptoms – “Central CHEST Pain”

Crushing central chest pain
Heavy/tight (not sharp)
Exertional or at rest
SOB, Sweating, Nausea, Vomiting
Time >15 mins, not relieved by GTN

Radiation: Left arm, jaw, neck, back

Atypical in elderly or diabetic: may present with SOB alone or silent

ECG Changes

Do within 10 minutes of arrival:

  • STEMI – ST elevation in contiguous leads, new LBBB

  • NSTEMI – ST depression, T wave inversion, or non-specific changes

  • Posterior MI – Reciprocal ST depression V1–V3 ± ST elevation in V7–V9

Bloods (NICE NG185 & CG95)

  • Troponin T/I:

    • Test at admission and repeat at 3–6 hours if initial normal

    • Positive if >99th percentile + clinical evidence of ischaemia

  • FBC, U&E, CRP/ESR, Glucose, Lipids, Coag screen

  • CXR if clinical suspicion of HF, dissection, or pulmonary cause

  • Consider coronary angiography if unstable/high-risk

Causes of ↑troponin (HEART DIES):
Heart failure, Embolism, AF, Renal failure, Thrombus, Dissection, Inflammation, Exercise, Sepsis

Risk Stratification – GRACE Score

Mnemonic: GRACE → Guide Revascularisation After Clinical Evaluation

  • >6% risk → early PCI (<72h)

  • <3% risk → conservative ± stress imaging

Initial Management

Mnemonic: MONA + BATMAN

MONA:

  • Morphine IV (if pain severe)

  • Oxygen (if sats <94%)

  • Nitrates (GTN) if SBP >90 mmHg

  • Aspirin 300 mg stat (chewed)

BATMAN:

  • Base PCI decision on GRACE score

  • Aspirin 300 mg +

  • Ticagrelor 180 mg (or Clopidogrel 600 mg)

  • Morphine IV

  • Antithrombin: Fondaparinux SC unless immediate PCI

  • Nitrates (repeat PRN)

Avoid IV β-blockers in unstable patients (bradycardia, hypotension, HF).

STEMI Reperfusion Therapy

  • Primary PCI within 120 minutes = gold standard

  • Thrombolysis (e.g. alteplase) if PCI delayed

    • Contraindications: active bleeding, recent surgery, aortic dissection, recent stroke, etc.

Post-MI Management

Mnemonic: BAGS + DAPT

  • Beta-blocker (unless contraindicated)

  • ACE inhibitor (start within 24h)

  • Glucose control (<11 mmol/L)

  • Statin – high intensity (e.g. atorvastatin 80 mg)

DAPT: Dual antiplatelet therapy for 12 months

  • Aspirin + Ticagrelor or Clopidogrel

Dressler’s Syndrome

Mnemonic: F-PER

  • Fever

  • Pleuritic chest pain

  • Effusion (pericardial)

  • Raised ESR
     Rx: NSAIDs

Complications

  • Arrhythmias (VT/VF, bradyarrhythmias)

  • Heart failure

  • Cardiogenic shock

  • LV aneurysm or rupture

  • Pericarditis / Dressler’s

  • Re-infarction

Secondary Prevention

Mnemonic: DREAM

  • Drug optimisation (BAGS + DAPT)

  • Rehabilitation (cardiac rehab)

  • Education (diet, exercise, adherence)

  • Alcohol & smoking cessation

  • Monitoring: BP, glucose, lipids

Avoid NSAIDs (esp. diclofenac)

Differential Diagnoses

Mnemonic: PEPP PANG

  • PE

  • Esophageal spasm / GORD

  • Pericarditis

  • Pneumothorax

  • Aortic dissection

  • Non-cardiac MSK pain

  • Generalised anxiety / panic

Last updated in line with NICE NG185 (Acute coronary syndromes):
Published December 2020, last updated October 2023
Review date: July 2025
PassMap ensures all content is NICE-aligned and reviewed for PARA success.

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