What is the recommended duration of dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor, such as clopidogrel, prasugrel, or ticagrelor, for patients who have undergone coronary artery procedures like percutaneous coronary intervention (PCI) with stent placement or have acute coronary syndrome (ACS)?

Duration of Dual Antiplatelet Therapy

For acute coronary syndrome (ACS) patients, dual antiplatelet therapy (DAPT) with aspirin plus a P2Y12 inhibitor should be continued for 12 months, regardless of whether they received a stent, medical management alone, or coronary artery bypass grafting. 1, 2, 3

Standard DAPT Duration by Clinical Scenario

Acute Coronary Syndrome (ACS)

• All ACS patients require 12 months of DAPT with aspirin 75-100 mg daily plus a P2Y12 inhibitor (ticagrelor, prasugrel, or clopidogrel), regardless of stent type (bare-metal or drug-eluting) or management strategy (PCI, medical therapy, or CABG). 1, 2, 3
• This applies to STEMI, NSTEMI, and unstable angina patients. 2
• For ACS patients treated with fibrinolytic therapy, P2Y12 inhibitor therapy should continue for a minimum of 14 days and ideally at least 12 months. 2

Stable Ischemic Heart Disease (SIHD) with PCI

• Bare-metal stent (BMS): Minimum 1 month of DAPT with clopidogrel plus aspirin. 1
• Drug-eluting stent (DES): At least 6 months of DAPT with clopidogrel plus aspirin. 1

P2Y12 Inhibitor Selection for ACS

The choice of P2Y12 inhibitor significantly impacts outcomes:

• First-line: Ticagrelor (180 mg loading dose, then 90 mg twice daily) is preferred over clopidogrel for most ACS patients. 1, 2, 3
• Second-line: Prasugrel (60 mg loading dose, then 10 mg daily) is reasonable for P2Y12 inhibitor-naïve patients without prior stroke/TIA and not at high bleeding risk. 1, 2, 3
• Third-line: Clopidogrel (600 mg loading dose, then 75 mg daily) should only be used when ticagrelor or prasugrel are contraindicated or unavailable. 2, 4
• Prasugrel is absolutely contraindicated in patients with prior stroke or TIA due to increased cerebrovascular bleeding risk. 1, 2, 3

Modifying DAPT Duration Based on Bleeding Risk

Shortened Duration (6 months)

• In ACS patients with high bleeding risk (e.g., PRECISE-DAPT score ≥25, requiring oral anticoagulation, major surgery planned, or significant overt bleeding), discontinuation of the P2Y12 inhibitor after 6 months may be reasonable. 1, 3
• For SIHD patients with DES who develop high bleeding risk, discontinuation after 3 months may be reasonable. 1

Extended Duration (Beyond 12 months)

• In ACS patients who have tolerated DAPT without bleeding complications and are not at high bleeding risk, continuation beyond 12 months may be reasonable. 1, 2, 3
• For extended therapy, ticagrelor 60 mg twice daily (reduced dose) may be preferred in high-risk MI patients who meet specific criteria: age ≥50 years plus at least one additional risk factor (age ≥65 years, diabetes requiring medication, second prior MI, multivessel CAD, or chronic kidney disease with creatinine clearance <60 mL/min). 2
• For SIHD patients with BMS or DES who have tolerated DAPT without bleeding, continuation beyond the minimum duration may be reasonable. 1

Critical Bleeding Risk Mitigation Strategies

Every patient on DAPT requires these protective measures:

• Prescribe a proton pump inhibitor (PPI) to all patients on DAPT to reduce gastrointestinal bleeding risk—this is a Class I recommendation. 2, 3, 4
• Maintain aspirin at 75-100 mg daily (not higher doses) when combined with a P2Y12 inhibitor. 1, 2, 3
• Use radial artery access over femoral access for PCI when performed by an experienced radial operator. 2, 4

Special Clinical Scenarios

Perioperative Management

• Never discontinue DAPT within the first month after stent placement for elective non-cardiac surgery—the thrombotic risk is highest during this period. 2, 4
• In ACS patients who undergo CABG while on DAPT, resume the P2Y12 inhibitor after surgery to complete 12 months of total DAPT therapy. 1, 2, 3
• Continue aspirin perioperatively if bleeding risk allows. 2, 4

Patients Requiring Anticoagulation

• In patients with atrial fibrillation requiring oral anticoagulation, triple therapy (aspirin, clopidogrel, and anticoagulant) should be given for 3-6 months, then transition to dual therapy (P2Y12 inhibitor plus anticoagulant). 3
• Clopidogrel is preferred over ticagrelor when combining with anticoagulation due to lower bleeding risk. 2

Common Pitfalls to Avoid

• Never use clopidogrel as first-line therapy when ticagrelor or prasugrel are available and not contraindicated—this represents suboptimal care for ACS patients. 2, 4
• Never discontinue DAPT prematurely, especially within the first month after stent placement—this dramatically increases risk of stent thrombosis, myocardial infarction, and death. 2, 4
• Never fail to prescribe a PPI with DAPT—this simple intervention significantly reduces gastrointestinal bleeding. 2, 4
• Never administer prasugrel to patients with prior stroke or TIA—this is contraindicated. 1, 2, 3

Decision-Making Algorithm

1. Confirm diagnosis: ACS or SIHD with PCI? 2, 3

   • ACS → 12 months DAPT mandatory
   • SIHD with BMS → 1 month minimum
   • SIHD with DES → 6 months minimum

2. Select P2Y12 inhibitor: 2, 3, 4

   • First choice: Ticagrelor (unless contraindicated)
   • Second choice: Prasugrel (if no prior stroke/TIA and not high bleeding risk)
   • Third choice: Clopidogrel (if above contraindicated)

3. Assess bleeding risk at baseline: 1, 3

   • High risk (PRECISE-DAPT ≥25) → Consider shortened duration (6 months for ACS, 3 months for SIHD with DES)
   • Low-moderate risk → Standard duration

4. Reassess at completion of standard duration: 1, 2, 3

   • Tolerated DAPT without bleeding + high ischemic risk → Consider extension with ticagrelor 60 mg twice daily
   • Developed bleeding or high bleeding risk → Discontinue P2Y12 inhibitor, continue aspirin monotherapy
   • Standard risk → Discontinue P2Y12 inhibitor, continue aspirin monotherapy

5. Ensure bleeding prophylaxis throughout: 2, 4

   • PPI for all patients
   • Aspirin 75-100 mg daily (not higher)
   • Radial access for procedures when possible