What are the guidelines for dual antiplatelet therapy (DAPT)?

From the Guidelines

Dual antiplatelet therapy (DAPT) should be used for at least 12 months in patients with acute coronary syndromes and those undergoing percutaneous coronary intervention (PCI) with stent placement, with the option to extend therapy beyond 12 months in patients at high ischemic risk and without high bleeding risk, as recommended by the 2021 ACC/AHA/SCAI guideline for coronary artery revascularization 1.

Key Considerations for DAPT Duration

• The duration of DAPT varies by clinical scenario, with 12 months being standard after acute coronary syndrome, and stable coronary disease with stent placement typically requiring 1-6 months depending on stent type and bleeding risk.
• High bleeding risk patients may receive shorter durations (3-6 months), while those at high ischemic risk might benefit from extended therapy beyond 12 months.
• For patients undergoing CABG surgery, DAPT should be held (clopidogrel/ticagrelor for 5 days, prasugrel for 7 days) before surgery unless urgent.

Mechanism of Action and Benefits of DAPT

• DAPT works by preventing platelet aggregation through two complementary mechanisms: aspirin inhibits thromboxane A2 production while P2Y12 inhibitors block ADP-mediated platelet activation.
• This provides more complete platelet inhibition than either agent alone and reduces the risk of stent thrombosis and recurrent cardiovascular events.

Clinical Scenarios and DAPT Recommendations

• Patients with acute coronary syndromes: at least 12 months of DAPT, with the option to extend therapy beyond 12 months in patients at high ischemic risk and without high bleeding risk.
• Patients with stable coronary disease and stent placement: 1-6 months of DAPT, depending on stent type and bleeding risk.
• Patients at high bleeding risk: shorter durations of DAPT (3-6 months) may be considered.
• Patients at high ischemic risk: extended therapy beyond 12 months may be considered.

From the Research

Dual Antiplatelet Therapy (DAPT) Guidelines

The guidelines for dual antiplatelet therapy (DAPT) are as follows:

• Conventional DAPT for patients with acute coronary syndromes undergoing percutaneous coronary intervention comprises aspirin with a potent P2Y12 inhibitor (prasugrel or ticagrelor) for 12 months 2.
• Strategies to reduce bleeding include de-escalation of DAPT intensity or abbreviation of DAPT duration, which requires assessment of the ischaemic and bleeding risks of each individual 2.
• De-escalation of DAPT intensity can reduce bleeding without increasing ischaemic events and can be guided by platelet function testing or genotyping 2, 3.
• Abbreviation of DAPT duration after 1-6 months, followed by monotherapy with aspirin or a P2Y12 inhibitor, reduces bleeding without an increase in ischaemic events in patients at high bleeding risk, particularly those without high ischaemic risk 2.

DAPT Duration

The optimal duration of DAPT is still a topic of debate:

• Current guidelines recommend a duration of DAPT with aspirin and oral P2Y12 receptor inhibitors following percutaneous coronary intervention with second-generation drug-eluting stents of 6 months for most patients with stable coronary disease and of 12 months for most patients with acute coronary syndromes 4.
• A study found that 6-month DAPT was non-inferior to 12-month DAPT in terms of the composite endpoint of all-cause death, myocardial infarction, or stroke, but myocardial infarction occurred more frequently in the 6-month DAPT group 5.
• The ischemic and bleeding risk balance is central to considering the duration of DAPT after an acute coronary syndrome, and individualization of DAPT duration may be necessary 6.

Personalized DAPT Approach

A personalized DAPT approach may be guided by platelet function testing (PFT) or genetic testing:

• Although the routine use of PFT or genetic testing in percutaneous coronary intervention-treated patients is not recommended, recent data have led to an update in guideline recommendations that allow considering selective use of PFT for DAPT de-escalation 3.
• An international expert consensus group recommends the selective use of PFT or genotyping in patients undergoing percutaneous coronary intervention to guide personalized treatment approaches 3.