For how long should dual antiplatelet therapy (with aspirin and a P2Y12 inhibitor, such as clopidogrel, prasugrel, or ticagrelor) be given to patients who have undergone percutaneous coronary intervention (PCI) with stent placement after a ST-elevation myocardial infarction (STEMI)?

Duration of Dual Antiplatelet Therapy After PCI for STEMI

Dual antiplatelet therapy (DAPT) with aspirin plus a P2Y12 inhibitor should be continued for at least 12 months in patients who undergo PCI with stent placement after STEMI. 1, 2

Standard DAPT Duration

• The minimum duration is 12 months for all STEMI patients treated with PCI and stent implantation, regardless of stent type (bare-metal or drug-eluting). 1, 2

• This 12-month recommendation applies equally to patients receiving medical therapy alone without revascularization. 1, 2

• For STEMI patients treated with fibrinolytic therapy, DAPT should be given for a minimum of 14 days and ideally extended to at least 12 months. 1

P2Y12 Inhibitor Selection

• Ticagrelor (90 mg twice daily) or prasugrel (10 mg daily) are preferred over clopidogrel (75 mg daily) for maintenance therapy after STEMI. 1, 2, 3

• Prasugrel should NOT be used in patients with prior stroke or TIA due to increased bleeding risk. 1, 2, 3

• Clopidogrel remains appropriate when ticagrelor or prasugrel are contraindicated or unavailable. 1, 2

Aspirin Dosing

• Low-dose aspirin (75-100 mg daily, typically 81 mg) should be used as part of DAPT and continued indefinitely. 1, 2, 3

• Higher aspirin doses increase bleeding risk without improving efficacy. 1, 2

Extension Beyond 12 Months

• In patients who tolerate DAPT without bleeding complications and have high ischemic risk, extending DAPT beyond 12 months (up to 3 years) may be considered. 1, 2

• For extended therapy beyond 12 months, ticagrelor 60 mg twice daily (not 90 mg) plus aspirin is the recommended regimen. 1, 2

• High ischemic risk features include: complex multivessel disease, prior MI, chronic kidney disease, or history of stent thrombosis. 2

Early Discontinuation Considerations

• In patients at high bleeding risk or who develop bleeding complications, discontinuation of the P2Y12 inhibitor after 6 months should be considered. 1, 2

• High bleeding risk can be assessed using the PRECISE-DAPT score (≥25 indicates high risk). 2, 4

• Aspirin should be continued even if the P2Y12 inhibitor is stopped early. 1, 2

Bleeding Risk Mitigation

• A proton pump inhibitor (PPI) should be prescribed with DAPT in all patients with history of GI bleeding or multiple bleeding risk factors. 1, 2, 3

• Risk factors include: age ≥65 years, concurrent anticoagulation, steroid/NSAID use, or H. pylori infection. 1

• Radial artery access (versus femoral) for PCI reduces bleeding complications when performed by experienced operators. 3

Critical Pitfalls to Avoid

• Do not discontinue DAPT prematurely within the first 12 months without compelling medical reasons (e.g., life-threatening bleeding, urgent surgery requiring cessation). 1, 2, 3

• Do not use aspirin doses >100 mg daily when combined with a P2Y12 inhibitor. 2, 3

• Do not fail to prescribe a PPI for gastroprotection in appropriate patients. 1, 2, 3

• Do not use prasugrel in patients with prior stroke/TIA. 1, 2, 3

• Do not automatically stop DAPT at exactly 12 months in high-risk patients who have tolerated therapy well—reassess bleeding and ischemic risk to determine if extension is appropriate. 1, 2

Special Circumstances

• If CABG is performed during the DAPT period, resume the P2Y12 inhibitor postoperatively to complete 12 months total DAPT duration from the STEMI event. 1, 2

• For patients requiring oral anticoagulation, triple therapy (aspirin + P2Y12 inhibitor + anticoagulant) should be limited to 1-6 months, then transition to dual therapy (P2Y12 inhibitor + anticoagulant, preferably clopidogrel). 1, 2