What is the research underlying Dual Antiplatelet Therapy (DAPT) and when did it become standard practice?

From the Guidelines

Dual antiplatelet therapy (DAPT) became standard practice in the early 2000s following several landmark clinical trials, with the most recent guidelines recommending DAPT for 12 months after drug-eluting stent implantation for acute coronary syndrome, as supported by the 2019 ESC/EACTS guidelines 1. The research underlying DAPT began with several key studies, including the CURE trial in 2001, which demonstrated that adding clopidogrel to aspirin significantly reduced cardiovascular events in patients with acute coronary syndromes.

Key Findings

• The standard regimen typically involves aspirin 81mg daily indefinitely plus a P2Y12 inhibitor (clopidogrel 75mg daily, prasugrel 10mg daily, or ticagrelor 90mg twice daily) for a duration that varies based on clinical scenario - generally 1 month for bare metal stents, 6-12 months for drug-eluting stents, and up to 12 months for acute coronary syndromes, as recommended by the 2016 ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease 1.
• DAPT works by inhibiting platelet aggregation through two complementary pathways: aspirin blocks the cyclooxygenase pathway while P2Y12 inhibitors block ADP-mediated platelet activation, providing more complete platelet inhibition than either agent alone and significantly reducing stent thrombosis and recurrent cardiovascular events.

Clinical Recommendations

• The 2019 ESC/EACTS guidelines recommend DAPT consisting of a P2Y12 receptor inhibitor in addition to aspirin for 12 months after PCI for NSTE-ACS, irrespective of the stent type 1.
• The duration of DAPT may vary based on individual patient risk factors, such as bleeding risk and ischemic risk, and should be tailored to the specific clinical scenario.
• The choice of P2Y12 inhibitor should be based on individual patient factors, such as renal function and history of bleeding, as well as the specific clinical scenario.

From the Research

Research Underlying DAPT

The research underlying Dual Antiplatelet Therapy (DAPT) is extensive and has been studied in various clinical trials and studies 2, 3, 4, 5, 6. DAPT combines two antiplatelet agents to decrease the risk of thrombotic complications associated with atherosclerotic cardiovascular diseases.

Key Findings

• 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 2.
• Short-term dual DAPT of 3-6 months, or even 1 month in high-bleeding risk patients, is equivalent in terms of efficacy and effectiveness compared to long-term DAPT for patients who experienced percutaneous coronary intervention in an acute coronary syndrome setting 3.
• Prolonged DAPT beyond 12 months reduces stent thrombosis, major adverse cardiovascular events, and myocardial infarction rates but increases bleeding risk 3, 5.

Standard Practice

• The American College of Cardiology/American Heart Association (ACC/AHA) recommended aspirin plus a P2Y12 inhibitor for at least 12 months for patients with acute coronary syndrome in 2016 4.
• However, recent studies suggest that abbreviated DAPT regimens may be associated with lower all-cause mortality and bleeding without compromising ischemic protection, supporting its use in specific patient populations 6.

Considerations for DAPT Duration

• The optimal duration of DAPT depends on individual patient characteristics, including the risk of bleeding and ischemic events 2, 3, 4, 5, 6.
• An individualized approach is needed, taking into account the competing risks of bleeding and ischemic events 5.
• Factors such as age, body weight, diabetes, and prior bleeding should be considered when determining the duration of DAPT 4.