What are the initial management and treatment guidelines for Acute Coronary Syndrome (ACS) according to NICE guidelines?

Initial Management and Treatment Guidelines for Acute Coronary Syndrome (ACS)

The initial management of Acute Coronary Syndrome requires immediate diagnosis, risk stratification, and appropriate pharmacological and invasive interventions based on the European Society of Cardiology guidelines, with timing of invasive strategy determined by patient risk level. 1

Immediate Diagnosis and Risk Stratification

Initial Evaluation (First 10 Minutes)

• Perform 12-lead ECG within 10 minutes of first medical contact
• Assess quality of chest pain and conduct symptom-oriented physical examination
• Evaluate likelihood of CAD (age, risk factors, previous MI, CABG, PCI)
• Assign patient to one of three working diagnoses:
  • STEMI
  • NSTE-ACS
  • ACS (highly) unlikely 1

Laboratory Assessment

• Draw blood on arrival for high-sensitivity cardiac troponin
• Results should be available within 60 minutes
• For inconclusive initial troponin, repeat after 3 hours 1

Risk Stratification

Risk stratification determines timing of invasive management:

1. Very High-Risk Features (immediate invasive strategy <2h):

   • Hemodynamic instability or cardiogenic shock
   • Recurrent/ongoing chest pain refractory to medical treatment
   • Life-threatening arrhythmias or cardiac arrest
   • Mechanical complications of MI
   • Acute heart failure with refractory angina or ST deviation
   • Recurrent dynamic ST/T-wave changes, particularly with intermittent ST elevation 1

2. High-Risk Features (early invasive strategy <24h):

   • Rise or fall in cardiac troponin compatible with MI
   • Dynamic ST- or T-wave changes (symptomatic or silent)
   • GRACE risk score >140 1

3. Intermediate-Risk Features (invasive strategy <72h):

   • Diabetes mellitus
   • Renal insufficiency (eGFR <60 mL/min/1.73 m²)
   • LVEF <40% or congestive heart failure
   • Early post-infarction angina
   • Recent PCI or prior CABG
   • GRACE risk score >109 and <140 1

Initial Pharmacological Management

Antiplatelet Therapy

• Aspirin: 150-300 mg loading dose (non-enteric formulation), followed by 75-100 mg daily maintenance dose 1
• P2Y12 inhibitor: Add one of the following:
  • Ticagrelor: Preferred for moderate to high-risk patients (180 mg loading dose, 90 mg twice daily) 1
  • Clopidogrel: For patients who cannot receive ticagrelor or prasugrel (300-600 mg loading dose, 75 mg daily) 1
  • Prasugrel: Only after coronary angiography when anatomy is known (60 mg loading dose, 10 mg daily) 1, 2
    • Caution: Not recommended in patients ≥75 years or with history of stroke/TIA 2

Anticoagulation

• Fondaparinux: 2.5 mg daily subcutaneously (preferred option) 1
• Enoxaparin: 1 mg/kg twice daily subcutaneously 1
• Unfractionated heparin: 60-70 IU/kg IV bolus (maximum 5000 IU), followed by infusion of 12-15 IU/kg/h (maximum 1000 IU/h) titrated to aPTT 1.5-2.5 × control 1
• Bivalirudin: Only indicated for patients with planned invasive strategy 1

Anti-ischemic Therapy

• Beta-blockers: Administer orally if tachycardic or hypertensive without signs of heart failure 1
• Nitrates: For ongoing chest pain 3
• Morphine: Consider for pain relief if nitrates ineffective 3

Invasive Management Strategy

NSTE-ACS

• Very high-risk patients: Immediate invasive strategy (<2h)
• High-risk patients: Early invasive strategy (<24h)
• Intermediate-risk patients: Invasive strategy within 72h 1

Revascularization

• Drug-eluting stents (DES) are recommended over bare-metal stents for any PCI 1
• Radial access is recommended as the standard approach 1
• Base revascularization strategy (culprit lesion PCI/multivessel PCI/CABG) on patient's clinical status, comorbidities, and disease severity 1

Secondary Prevention

• Statins: High-intensity statin therapy as early as possible after admission 1
• ACE inhibitors/ARBs: For patients with left ventricular dysfunction, heart failure, hypertension, or diabetes 3
• Beta-blockers: Continue long-term, especially in patients with reduced left ventricular function 3

Special Considerations

Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA)

• Follow diagnostic algorithm to differentiate true MINOCA from alternative diagnoses
• Perform cardiac MRI in all MINOCA patients without an obvious underlying cause 1

ACS with Heart Failure or Cardiogenic Shock

• Emergency coronary angiography is recommended
• Emergency PCI of the culprit lesion is recommended if coronary anatomy is amenable
• Emergency CABG if coronary anatomy is not amenable to PCI
• Perform emergency echocardiography to assess LV and valvular function 1

Elderly Patients

• Apply the same diagnostic and interventional strategies as for younger patients
• Adapt antithrombotic agent choice and dosage to renal function and specific contraindications 1

Common Pitfalls and Caveats

• Prasugrel: Do not administer in patients with unknown coronary anatomy 1
• Bleeding risk: Consider weight (<60 kg), age (>75 years), and renal function when dosing antithrombotics 2
• Diagnosis: Assignment to "ACS unlikely" category must be done with caution and only when another explanation is obvious 1
• Timing: Delay between symptom onset and treatment significantly impacts outcomes - minimize delays at all stages

The management of ACS requires rapid assessment, risk stratification, and appropriate treatment to reduce morbidity and mortality. Following these guidelines ensures optimal patient outcomes through evidence-based care.