What is the indication for antiplatelet therapy after Percutaneous Coronary Intervention (PCI)?

Antiplatelet Therapy After Percutaneous Coronary Intervention (PCI)

Dual antiplatelet therapy (DAPT) consisting of aspirin 75-100 mg and a P2Y12 inhibitor is recommended for up to 6 months as the default antithrombotic strategy after PCI with drug-eluting stents in patients with chronic coronary syndrome (CCS), with duration adjustments based on individual bleeding and ischemic risk profiles. 1

Standard DAPT Recommendations After PCI

For Acute Coronary Syndrome (ACS) Patients:

• DAPT with aspirin and a P2Y12 inhibitor is indicated for at least 12 months 1
• Ticagrelor or prasugrel is recommended in preference to clopidogrel for ACS patients undergoing PCI 1
• Loading dose followed by daily maintenance:
  • Aspirin: 81-325 mg loading, then 75-100 mg daily indefinitely 1, 2
  • P2Y12 inhibitor options:
    • Clopidogrel: 600 mg loading, then 75 mg daily 2
    • Prasugrel: 60 mg loading, then 10 mg daily (5 mg if <60 kg) 3
    • Ticagrelor: 180 mg loading, then 90 mg twice daily 2

For Chronic Coronary Syndrome (CCS) Patients:

• DAPT with aspirin 75-100 mg and clopidogrel 75 mg daily for up to 6 months 1
• In patients at high bleeding risk but not high ischemic risk, discontinue DAPT 1-3 months after PCI and continue single antiplatelet therapy 1
• Stopping DAPT after 1-3 months may be considered in patients who are neither at high bleeding nor high ischemic risk 1

Risk-Based DAPT Duration Adjustments

Shorter DAPT Duration (1-3 months):

• Indicated for patients at high bleeding risk 1
• Recent evidence suggests short DAPT (≤3 months) followed by P2Y12 inhibitor monotherapy (particularly ticagrelor) reduces net adverse clinical events and bleeding without increasing ischemic events 4

Extended DAPT Duration (>6-12 months):

• Consider for patients at enhanced ischemic risk without high bleeding risk 1
• Extended DAPT (18-48 months) compared to 6-12 months shows:
  • Decreased MI (OR: 0.67; 95% CI: 0.47 to 0.95)
  • Decreased stent thrombosis (OR: 0.45; 95% CI: 0.24 to 0.74)
  • Increased major hemorrhage (OR: 1.58; 95% CI: 1.20 to 2.09) 1

Special Populations

Patients Requiring Oral Anticoagulation:

• For patients with atrial fibrillation requiring PCI:
  • Initial low-dose aspirin plus OAC and clopidogrel is recommended 1
  • Early cessation of aspirin (≤1 week) followed by OAC plus clopidogrel for up to 6 months (or 12 months if high ischemic risk) 1
  • Continuation of aspirin up to 1 month may be considered in patients at high ischemic risk 1
  • Direct oral anticoagulants (DOACs) are preferred over vitamin K antagonists 1

High Thrombotic Risk PCI:

• For complex left main, 2-stent bifurcation, suboptimal stenting result, prior stent thrombosis, or known CYP2C19 *2/*3 polymorphisms:
  • Consider prasugrel or ticagrelor (instead of clopidogrel) for the first month, up to 3-6 months 1

Bleeding Risk Reduction Strategies

• Proton pump inhibitor is recommended for patients at risk of gastrointestinal bleeding 1, 2
• Radial approach is preferred over femoral approach to reduce bleeding and vascular complications 1
• For patients on ticagrelor who have tolerated DAPT, transition to ticagrelor monotherapy is recommended ≥1 month after PCI 1

Common Pitfalls and Considerations

1. Premature DAPT discontinuation: Increases risk of stent thrombosis, particularly in the first months after PCI
2. Inadequate patient counseling: Poor adherence to DAPT is associated with increased adverse events
3. Failure to consider both bleeding and ischemic risks: Both must be assessed to determine optimal DAPT duration
4. Overlooking drug interactions: Some medications may affect P2Y12 inhibitor metabolism or increase bleeding risk

Algorithm for DAPT Duration Decision-Making

1. Assess patient's baseline ischemic risk (ACS vs. CCS, complex PCI, diabetes, prior MI)
2. Assess patient's bleeding risk (age >75, weight <60kg, prior bleeding, oral anticoagulant use)
3. Determine DAPT duration:
   • High bleeding risk: 1-3 months DAPT, then single antiplatelet therapy
   • Standard risk: 6 months for CCS, 12 months for ACS
   • High ischemic risk without high bleeding risk: Consider extended DAPT >12 months

The evolution of stent technology and growing evidence base has led to more personalized approaches to antiplatelet therapy after PCI, with a careful balance between preventing thrombotic complications and minimizing bleeding risk.