What is the preferred dual antiplatelet therapy after percutaneous coronary intervention?

Preferred Dual Antiplatelet Therapy After Percutaneous Coronary Intervention

The preferred dual antiplatelet therapy after PCI consists of aspirin 75-100 mg daily plus a potent P2Y12 inhibitor—specifically ticagrelor (90 mg twice daily after 180 mg loading) or prasugrel (10 mg daily after 60 mg loading)—with clopidogrel (75 mg daily) reserved only when these agents are unavailable or contraindicated. 1, 2

Standard DAPT Regimen Components

Aspirin Component

• Loading dose: 150-300 mg oral (or 75-250 mg IV) at the time of PCI 1
• Maintenance dose: 75-100 mg daily, continued long-term 1
• Higher aspirin doses (>100 mg) should be avoided when combined with P2Y12 inhibitors due to increased bleeding without additional ischemic benefit 2

P2Y12 Inhibitor Selection Hierarchy

First-line agents (potent P2Y12 inhibitors):

1. Ticagrelor 1, 2

   • Loading: 180 mg before or at time of PCI
   • Maintenance: 90 mg twice daily
   • Preferred for acute coronary syndrome patients
   • Class I, Level A recommendation

2. Prasugrel 1, 2

   • Loading: 60 mg at time of PCI
   • Maintenance: 10 mg daily
   • Contraindicated in patients with prior stroke/TIA
   • Avoid if age ≥75 years or body weight <60 kg

Second-line agent:

1. Clopidogrel 1
   • Loading: 600 mg (though not explicitly stated in guidelines, this is standard practice)
   • Maintenance: 75 mg daily
   • Use only when ticagrelor or prasugrel are unavailable or contraindicated
   • Acceptable for stable chronic coronary syndrome

Duration of DAPT

Standard Duration by Clinical Scenario

Acute Coronary Syndrome (STEMI or NSTEMI):

• 12 months of DAPT is the default duration for all ACS patients without high bleeding risk 1, 2
• This applies regardless of stent type, completeness of revascularization, or management strategy 2

Chronic Coronary Syndrome (Stable CAD):

• 6 months of DAPT is the default duration after drug-eluting stent implantation 1, 3
• 1 month for bare-metal stents 3

Shortened DAPT for High Bleeding Risk

• 1-3 months of DAPT followed by single antiplatelet therapy is recommended for patients at high bleeding risk (e.g., PRECISE-DAPT score ≥25) who are not at high ischemic risk 1
• Aspirin should be discontinued first, with continuation of the P2Y12 inhibitor 1, 2

Extended DAPT Considerations

• Extension beyond 12 months may be considered in patients at high ischemic risk who have tolerated DAPT without bleeding complications 1
• High ischemic risk includes: complex left main stenting, 2-stent bifurcation, suboptimal stenting result, prior stent thrombosis, or prior MI 1

Mandatory Bleeding Risk Mitigation

All patients on DAPT must receive:

• Proton pump inhibitor (Class I recommendation) to reduce gastrointestinal bleeding 1, 2
• Pantoprazole 40 mg daily is preferred due to minimal CYP2C19 interaction with clopidogrel 2

Procedural considerations:

• Radial artery access preferred over femoral when performed by experienced operator 2

Transition Strategy After DAPT

Standard Approach (No Oral Anticoagulation)

After completing the recommended DAPT duration:

• Discontinue aspirin and continue P2Y12 inhibitor monotherapy, OR 1, 2
• Continue aspirin monotherapy (traditional approach) 1

Emerging evidence favors P2Y12 inhibitor monotherapy over aspirin monotherapy because it provides equivalent ischemic protection with lower bleeding risk 4, 5, 6, 7

Special Scenario: Patients Requiring Oral Anticoagulation

Initial strategy (peri-PCI):

• Triple therapy (OAC + aspirin + clopidogrel) during hospitalization 1

Post-discharge strategy (default for most patients):

• Discontinue aspirin within 1 week after uncomplicated PCI 1
• Continue double therapy (OAC + clopidogrel) for 6-12 months depending on ischemic risk 1
• NOAC preferred over warfarin 1

High ischemic/low bleeding risk patients:

• May extend triple therapy up to 1 month (rarely beyond) 1

After 6-12 months:

• Discontinue clopidogrel and continue OAC monotherapy at full stroke-prevention dose 1

Critical Pitfalls to Avoid

1. Never discontinue both antiplatelet agents simultaneously within the first month after stent placement—this dramatically increases stent thrombosis, MI, and death risk 3, 2

2. Never omit PPI prescription with DAPT—this simple intervention significantly reduces GI bleeding without compromising efficacy 1, 2

3. Never use clopidogrel as first-line therapy when ticagrelor or prasugrel are available and not contraindicated in ACS patients—this represents suboptimal care 2

4. Never administer prasugrel to patients with prior stroke/TIA—this is an absolute contraindication due to increased intracranial bleeding 2

5. Never use triple therapy (OAC + aspirin + P2Y12 inhibitor) long-term—bleeding risk increases 2-3 fold without proportional ischemic benefit 1

6. Never delay P2Y12 inhibitor loading dose—it should be given before or at latest at the time of PCI 1

Algorithm for P2Y12 Inhibitor Selection

Step 1: Identify clinical presentation

• ACS (STEMI/NSTEMI) → Proceed to Step 2
• Stable CAD → Clopidogrel acceptable; ticagrelor/prasugrel may be considered for complex procedures 1

Step 2: Screen for prasugrel contraindications

• Prior stroke/TIA? → Use ticagrelor
• Age ≥75 years? → Use ticagrelor
• Body weight <60 kg? → Use ticagrelor
• None of the above? → Either prasugrel or ticagrelor acceptable

Step 3: Screen for ticagrelor contraindications

• Prior intracranial hemorrhage? → Use clopidogrel
• Active bleeding? → Use clopidogrel
• Requires oral anticoagulation? → Use clopidogrel (lower bleeding risk in triple therapy) 2
• Severe bradycardia or high-degree AV block without pacemaker? → Use clopidogrel or prasugrel

Step 4: Default choice for ACS without contraindications

• Ticagrelor 180 mg loading, then 90 mg twice daily 1, 2