Should I use dual antiplatelet therapy (DAPT) or aspirin monotherapy after percutaneous coronary intervention (PCI)?

Dual Antiplatelet Therapy After PCI: DAPT vs. Aspirin Monotherapy

For most patients after PCI, dual antiplatelet therapy (DAPT) is recommended initially, with a duration based on clinical presentation and bleeding risk, followed by transition to P2Y12 inhibitor monotherapy rather than aspirin alone. 1

Initial DAPT Duration Based on Clinical Presentation

For Stable Ischemic Heart Disease (SIHD):

• Drug-eluting stent (DES): At least 1-3 months of DAPT (aspirin plus clopidogrel), then transition to P2Y12 inhibitor monotherapy 1
• Bare metal stent (BMS): At least 1 month of DAPT (aspirin plus clopidogrel) 1

For Acute Coronary Syndrome (ACS):

• At least 12 months of DAPT (aspirin plus a P2Y12 inhibitor - preferably ticagrelor or prasugrel) 1
• Consider transition to P2Y12 inhibitor monotherapy after 1-3 months if bleeding risk is high 1

P2Y12 Inhibitor Selection

• For SIHD: Clopidogrel is the preferred P2Y12 inhibitor 1
• For ACS: Ticagrelor or prasugrel preferred over clopidogrel 1, 2
• For patients ≥75 years or <60 kg: Consider avoiding prasugrel due to increased bleeding risk 2

Transition to Monotherapy

Evidence-Based Approach:

1. After completing the initial DAPT period:

   • Transition to P2Y12 inhibitor monotherapy (particularly ticagrelor or clopidogrel) rather than aspirin alone 1, 3, 4
   • This strategy reduces major adverse cardiac events (MACE) and bleeding events compared to continued DAPT or aspirin monotherapy 3, 4

2. Specific benefits of P2Y12 monotherapy:

   • Clopidogrel monotherapy after DAPT completion shows reduced MACE (RR 0.77) and stroke (RR 0.51) compared to aspirin monotherapy 4
   • Short DAPT (≤3 months) followed by P2Y12 inhibitor monotherapy reduces net adverse clinical events and major bleeding without increasing ischemic events 3, 5

Special Considerations

High Bleeding Risk Patients:

• Consider shorter DAPT duration (1-3 months) followed by P2Y12 inhibitor monotherapy 1
• For patients with overt bleeding on DAPT, consider reducing to 3 months of DAPT 1

Patients Requiring Oral Anticoagulation:

• Triple therapy (DAPT plus anticoagulation) should be limited to a maximum of 6 months or omitted after hospital discharge 6
• Use clopidogrel as the P2Y12 inhibitor with low-dose aspirin (75-100 mg daily) 6
• Consider discontinuing aspirin after 1-4 weeks and continuing P2Y12 inhibitor (preferably clopidogrel) with anticoagulation 1

Common Pitfalls to Avoid

1. Premature DAPT discontinuation: Especially within first month after PCI, which increases stent thrombosis risk 1, 7

2. Prolonging DAPT unnecessarily: Extended DAPT beyond recommended duration increases bleeding risk without significant reduction in ischemic events in most patients 3, 8

3. Using prasugrel or ticagrelor with oral anticoagulation: This combination significantly increases bleeding risk 1, 6

4. Ignoring bleeding risk factors: Weight <60 kg, age ≥75 years, prior bleeding, concomitant anticoagulants or NSAIDs 2

5. Overlooking the benefit of P2Y12 monotherapy: Recent evidence supports P2Y12 inhibitor monotherapy over aspirin alone after completing initial DAPT 3, 4, 5

In conclusion, the optimal approach is to provide DAPT for the appropriate duration based on clinical presentation and bleeding risk, followed by transition to P2Y12 inhibitor monotherapy rather than aspirin alone or continued DAPT. This strategy provides the best balance between preventing ischemic events and minimizing bleeding complications.