What is the recommended duration of dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor for a patient with acute coronary syndrome or coronary artery stenting?

Recommended Duration of Dual Antiplatelet Therapy

For patients with acute coronary syndrome (ACS) or coronary artery stenting, dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor should be continued for at least 12 months. 1

Standard DAPT Duration by Clinical Scenario

Acute Coronary Syndrome (ACS)

• 12 months is the mandatory minimum duration for all ACS patients (STEMI, NSTEMI, unstable angina) treated with coronary stent implantation (bare metal or drug-eluting stents), regardless of stent type 1
• This recommendation applies whether patients undergo PCI, medical management alone, or CABG 1
• After CABG in ACS patients, P2Y12 inhibitor therapy should be resumed postoperatively to complete the full 12-month course 1

Stable Ischemic Heart Disease (SIHD)

• Bare metal stents (BMS): Minimum 1 month of DAPT 1
• Drug-eluting stents (DES): Minimum 6 months of DAPT 1

Optimal P2Y12 Inhibitor Selection

First-Line Agents for ACS

• Ticagrelor (180 mg loading, 90 mg twice daily) is preferred over clopidogrel for ACS patients undergoing PCI 1, 2
• Prasugrel (60 mg loading, 10 mg daily) is reasonable for P2Y12-naïve ACS patients undergoing PCI who have no history of stroke/TIA and are not at high bleeding risk 1, 2
• Clopidogrel (600 mg loading, 75 mg daily) should be reserved for patients with contraindications to ticagrelor or prasugrel, such as prior intracranial hemorrhage or need for oral anticoagulation 2

Critical Contraindication

• Prasugrel is absolutely contraindicated (Class III: Harm) in patients with prior stroke or TIA due to increased risk of cerebrovascular bleeding 1, 2

Aspirin Dosing

• Daily aspirin dose should be 81 mg (range 75-100 mg) when used in combination with a P2Y12 inhibitor to minimize bleeding risk while maintaining efficacy 1, 2

Duration Modification Based on Bleeding Risk

Shortened Duration (High Bleeding Risk)

• 6 months of DAPT may be reasonable in ACS patients who develop high bleeding risk (e.g., need for oral anticoagulation, major surgery planned, significant overt bleeding) 1
• 3 months of DAPT can be considered in stable CAD patients with high bleeding risk after DES implantation 1
• High bleeding risk is defined by factors including: prior bleeding on DAPT, coagulopathy, oral anticoagulant use, age >75 years, weight <60 kg, or PRECISE-DAPT score ≥25 1, 2

Extended Duration (Low Bleeding Risk)

• Continuation beyond 12 months may be reasonable in ACS patients who have tolerated DAPT without bleeding complications and are not at high bleeding risk 1
• Extended DAPT reduces stent thrombosis and major adverse cardiovascular events but increases bleeding risk, requiring careful patient selection 3, 4, 5

Bleeding Risk Mitigation Strategies

Mandatory Interventions

• Prescribe a proton pump inhibitor (PPI) with DAPT to reduce gastrointestinal bleeding risk 2
• Use radial over femoral access for coronary angiography and PCI when performed by an expert radial operator 2
• Maintain low-dose aspirin (75-100 mg daily) rather than higher doses 2

Critical Pitfalls to Avoid

Premature Discontinuation

• Never discontinue DAPT within the first month after stent placement for elective non-cardiac surgery, as this dramatically increases the risk of catastrophic stent thrombosis 1, 2
• The risk of stent thrombosis is highest in the first days to weeks after implantation 1

Suboptimal P2Y12 Inhibitor Selection

• Do not use clopidogrel as first-line therapy in ACS patients when ticagrelor or prasugrel are available and not contraindicated 2
• Do not administer prasugrel to patients with prior stroke/TIA under any circumstances 1, 2

Switching Between P2Y12 Inhibitors

• In ACS patients previously on clopidogrel, switch to ticagrelor early after hospital admission with a 180 mg loading dose, regardless of clopidogrel timing or loading dose 2

Failure to Prescribe PPI

• Always prescribe a PPI with DAPT—this simple intervention significantly reduces gastrointestinal bleeding without compromising antiplatelet efficacy 2

Special Considerations for Triple Therapy

• When oral anticoagulation is required with DAPT, prefer clopidogrel over ticagrelor due to significantly lower bleeding risk 2
• Consider discontinuing aspirin 1-4 weeks after PCI and continuing P2Y12 inhibitor (preferably clopidogrel) with anticoagulation 2