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

From the Guidelines

Dual antiplatelet therapy (DAPT) is recommended for 12 months in patients with acute coronary syndrome (ACS) who are managed with medical therapy alone, with ticagrelor preferred over clopidogrel unless the bleeding risk outweighs the potential ischemic benefit 1. The standard regimen for DAPT includes aspirin 81mg daily indefinitely plus a P2Y12 inhibitor (clopidogrel 75mg daily, ticagrelor 90mg twice daily, or prasugrel 10mg daily) for a duration that depends on the clinical scenario.

• For patients with bare metal stents, DAPT should continue for at least 1 month.
• For drug-eluting stents, DAPT should continue for at least 6-12 months.
• In ACS patients, DAPT is recommended for 12 months regardless of stent type.
• Extended DAPT beyond 12 months may be considered for high-risk patients with low bleeding risk.
• The duration may be shortened to 3-6 months for patients with high bleeding risk. Aspirin should be given as a loading dose of 325mg initially, then maintained at 81mg daily, while P2Y12 inhibitors also require loading doses (clopidogrel 300-600mg, ticagrelor 180mg, prasugrel 60mg) before maintenance dosing. DAPT works by preventing platelet aggregation through two complementary mechanisms: aspirin inhibits thromboxane A2 production while P2Y12 inhibitors block ADP-mediated platelet activation, providing more complete platelet inhibition than either agent alone. The most recent guidelines from 2022 support the use of DAPT for patients after percutaneous coronary intervention (PCI), with recommendations for the duration of DAPT based on the type of stent used and the patient's clinical scenario 1. Key considerations in determining the duration of DAPT include the patient's risk of bleeding and ischemic events, as well as their ability to tolerate the therapy. In general, patients with a high risk of bleeding may require a shorter duration of DAPT, while those with a low risk of bleeding may benefit from extended DAPT. Ultimately, the decision to extend or shorten the duration of DAPT should be individualized based on the patient's specific clinical characteristics and needs.

From the Research

Guidelines for Dual Antiplatelet Therapy (DAPT)

• The optimal duration of DAPT after percutaneous coronary intervention (PCI) should consider patient-specific risk, clinical presentation, stent characteristics, and procedural factors 2.
• Current guidelines recommend a duration of DAPT with aspirin and oral P2Y12 receptor inhibitors following PCI with second-generation drug-eluting stents (DES) of 6 months for most patients with stable coronary disease and of 12 months for most patients with acute coronary syndromes 3.
• However, recent studies suggest that shorter duration of DAPT (≤3 months or 6 months) may be safe and effective in patients with acute coronary syndrome (ACS) undergoing PCI, with a significant reduction in bleeding outcomes compared to long-term DAPT (12 months and >12 months) 4, 5.
• Ticagrelor monotherapy following short-term DAPT in ACS undergoing PCI has been shown to be associated with a significant reduction in major and minor bleeding, net adverse clinical and cerebral events (NACCE), and all-cause mortality compared to 12-month DAPT 5.

DAPT Duration Strategies

• Multiple DAPT de-escalation treatment strategies, including switching from prasugrel or ticagrelor to clopidogrel, reducing the dose of prasugrel or ticagrelor, and shortening DAPT duration while maintaining monotherapy with ticagrelor, have been consistently shown to reduce bleeding without increasing fatal or nonfatal cardiovascular or cerebral ischemic risks compared with 12-month DAPT 6.
• Short-term DAPT (≤3 months or 6 months) did not increase ischemic outcomes compared to long-term DAPT (12 months and >12 months) in patients with ACS undergoing PCI 4.
• Ultrashort-term DAPT (≤1 month) followed by ticagrelor monotherapy for up to 12 months has also been shown to be effective in reducing bleeding outcomes 5.

Bleeding Risk Assessment

• Bleeding risk assessment has emerged as a treatment modifier for maximizing the net clinical benefit of DAPT, due to excessive bleeding and no clear benefit of prolonged treatment regimens in high bleeding risk patients 6.
• High bleeding risk patients may benefit from shorter duration of DAPT or de-escalation treatment strategies to minimize bleeding risk while maintaining efficacy 6, 2.