What are the indications for dual antiplatelet therapy (DAPT)?

Indications for Dual Antiplatelet Therapy (DAPT)

Dual antiplatelet therapy is primarily indicated for acute coronary syndrome, percutaneous coronary intervention with stent placement, and certain high-risk cardiovascular conditions to reduce morbidity and mortality from thrombotic events. 1

Primary Indications for DAPT

1. Acute Coronary Syndrome (ACS)

• ACS treated with PCI: DAPT with aspirin plus a P2Y12 inhibitor for 12 months 1

  • Ticagrelor (180 mg loading dose, 90 mg twice daily) is recommended for all ACS patients regardless of treatment strategy 1
  • Prasugrel (60 mg loading dose, 10 mg daily) is recommended for P2Y12-naïve ACS patients undergoing PCI 1
  • Prasugrel should be considered in preference to ticagrelor for NSTE-ACS patients proceeding to PCI 1

• ACS managed with medical therapy alone: DAPT for 12 months 1

  • Ticagrelor is recommended over clopidogrel unless bleeding risk outweighs ischemic benefit 1
  • Prasugrel is not recommended in medically managed ACS patients 1

2. Elective PCI with Stent Placement

• Clopidogrel (600 mg loading dose, 75 mg daily) plus aspirin is recommended for stable CAD patients undergoing coronary stent implantation 1

3. STEMI with Thrombolysis

• Clopidogrel (300 mg loading dose in patients <75 years, 75 mg daily) plus aspirin is recommended in STEMI patients receiving thrombolysis 1

Duration of DAPT

Standard Duration

• ACS (with or without PCI): 12 months 1
• Stable CAD with PCI: 6 months (can be shortened to 3 months in high bleeding risk patients) 2, 3

Modified Duration Based on Risk Assessment

• Shortened duration (3-6 months): For patients with high bleeding risk (e.g., PRECISE-DAPT ≥25) 1
• Extended duration (>12 months): May be considered in ACS patients who have tolerated DAPT without bleeding complications and are at high risk for ischemic events 1, 4

P2Y12 Inhibitor Selection

First-line options:

• Ticagrelor: Preferred for all ACS patients regardless of management strategy 1, 5
• Prasugrel: Preferred for ACS patients undergoing PCI 1
• Clopidogrel: Recommended for:
  • Stable CAD patients undergoing PCI 1
  • ACS patients who cannot receive ticagrelor or prasugrel 1
  • Patients with indication for oral anticoagulation 1

Measures to Minimize Bleeding Risk

1. Use radial over femoral access for coronary angiography and PCI 1
2. Use low-dose aspirin (75-100 mg daily) 1
3. Add proton pump inhibitor to DAPT regimen 1, 5
4. Avoid routine platelet function testing to adjust therapy 1

Special Considerations

Patients Requiring Surgery

• Continue aspirin perioperatively if bleeding risk allows 1
• Do not discontinue DAPT within the first month after stent implantation 1
• For elective surgery requiring P2Y12 inhibitor discontinuation:
  • Consider waiting at least 1 month after stent implantation 1
  • If both antiplatelet agents must be discontinued, consider bridging strategy with cangrelor, tirofiban, or eptifibatide 1

Patients with Oral Anticoagulation

• Triple therapy duration should be limited to a maximum of 6 months 1
• Ticagrelor or prasugrel are not recommended in this setting 1

Common Pitfalls to Avoid

1. Premature DAPT discontinuation: Especially within the first month after stent implantation, which significantly increases the risk of stent thrombosis 1

2. Inappropriate P2Y12 inhibitor selection:

   • Administering prasugrel to medically managed ACS patients 1
   • Using prasugrel in patients with prior stroke/TIA or high bleeding risk 1

3. Routine pre-treatment with P2Y12 inhibitors: Not recommended in NSTE-ACS patients when coronary anatomy is unknown and early invasive management is planned 1

4. Overlooking bleeding risk: Failure to adjust DAPT duration based on individual bleeding risk can lead to preventable bleeding complications 1, 4

5. Inappropriate DAPT duration: Extended DAPT beyond 12 months increases bleeding risk without significantly reducing mortality in stable patients 2, 3

By following these evidence-based recommendations, clinicians can optimize the use of DAPT to reduce thrombotic events while minimizing bleeding complications in patients with cardiovascular disease.