What are the first-line treatment options for patients requiring anti-platelet (anti-thrombotic) therapy?

First-Line Antiplatelet Therapy Options

For patients requiring antiplatelet therapy, low-dose aspirin (75-100 mg daily) is the first-line treatment for established coronary artery disease, while dual antiplatelet therapy (DAPT) with aspirin plus a P2Y12 inhibitor is recommended for patients with acute coronary syndromes or following percutaneous coronary intervention. 1

Primary Prevention

• For persons aged 50 years or older without symptomatic cardiovascular disease, low-dose aspirin 75-100 mg daily may be considered (Grade 2B) 1
• Benefits must be weighed against bleeding risk, particularly in those with low cardiovascular risk

Secondary Prevention (Established Coronary Artery Disease)

Stable Coronary Artery Disease

• Single antiplatelet therapy (SAPT):
  • Aspirin 75-100 mg daily (first choice) OR
  • Clopidogrel 75 mg daily (if aspirin intolerance/allergy)
  • Long-term therapy recommended (Grade 1A) 1

Post-Acute Coronary Syndrome (ACS)

• Dual antiplatelet therapy (DAPT) for 12 months:
  • Aspirin 75-100 mg daily PLUS one of:
    • Ticagrelor 90 mg twice daily (preferred over clopidogrel) 1
    • Clopidogrel 75 mg daily
    • Prasugrel 10 mg daily (for PCI patients only)
  • After 12 months, transition to single antiplatelet therapy (Grade 1B) 1

Post-Percutaneous Coronary Intervention (PCI)

• With bare-metal stent:
  • DAPT (aspirin + clopidogrel) for minimum 1 month, ideally up to 12 months 1, 2
• With drug-eluting stent:
  • DAPT for minimum 3-6 months (depending on stent type)
  • 3 months minimum for "-limus" stents
  • 6 months minimum for "-taxel" stents
  • Consider continuing DAPT for 12 months (Grade 2C) 1

Special Considerations

P2Y12 Inhibitor Selection

• Clopidogrel (75 mg daily):

  • First-line P2Y12 inhibitor for stable CAD
  • Loading dose: 300-600 mg 3
  • Caution in CYP2C19 poor metabolizers 3

• Ticagrelor (90 mg twice daily):

  • Preferred over clopidogrel in ACS 1
  • Loading dose: 180 mg
  • Does not require metabolic activation
  • Contraindicated with history of intracranial hemorrhage 2

• Prasugrel (10 mg daily):

  • Only for PCI-treated patients
  • Loading dose: 60 mg
  • Avoid in patients >75 years, <60 kg, or with prior stroke/TIA 1, 4

Bleeding Risk Considerations

• For patients at high bleeding risk (PRECISE-DAPT score ≥25), consider shorter DAPT duration (6 months) 1
• In patients requiring triple therapy (DAPT + oral anticoagulant), clopidogrel is preferred over other P2Y12 inhibitors 2
• Minimize triple therapy duration (≤1 month) when possible 2

Perioperative Management

• For non-cardiac surgery after stent placement:
  • Postpone elective procedures when possible
  • Discontinue ticagrelor ≥3 days before surgery
  • Discontinue clopidogrel ≥5 days before surgery
  • Discontinue prasugrel ≥7 days before surgery 2

Common Pitfalls to Avoid

1. Premature discontinuation of DAPT after stent placement increases risk of stent thrombosis, MI, and death
2. Inappropriate P2Y12 inhibitor selection (e.g., prasugrel in patients >75 years or with prior stroke)
3. Overlooking drug interactions (e.g., PPIs may reduce clopidogrel efficacy)
4. Failing to transition from DAPT to SAPT after the recommended duration
5. Not considering bleeding risk when selecting antiplatelet regimen and duration

Algorithm for Antiplatelet Selection

1. Assess indication:

   • Primary prevention → Consider aspirin 75-100 mg daily
   • Stable CAD → SAPT (aspirin or clopidogrel)
   • ACS or post-PCI → DAPT for recommended duration

2. Evaluate bleeding risk:

   • High bleeding risk → Consider shorter DAPT duration
   • Low bleeding risk → Standard DAPT duration

3. Select appropriate P2Y12 inhibitor for DAPT:

   • ACS → Ticagrelor preferred (if no contraindications)
   • PCI → Prasugrel or ticagrelor (if no contraindications)
   • High bleeding risk or need for oral anticoagulation → Clopidogrel

4. Plan for transition to SAPT:

   • After recommended DAPT duration (typically 12 months for ACS)
   • Continue aspirin for long-term therapy in most cases

By following these evidence-based recommendations, clinicians can optimize antiplatelet therapy to reduce cardiovascular events while minimizing bleeding complications.