From the Guidelines
For patients with ST-Elevation Myocardial Infarction (STEMI), the recommended duration of Dual Antiplatelet Therapy (DAPT) is generally 12 months, as stated in the 2017 ESC guidelines 1 and 2016 ACC/AHA guideline focused update 1. The standard DAPT regimen consists of aspirin 81 mg daily indefinitely, combined with a P2Y12 inhibitor such as clopidogrel 75 mg daily, ticagrelor 90 mg twice daily, or prasugrel 10 mg daily for 12 months. For the initial loading dose, aspirin 325 mg should be given immediately, along with a P2Y12 inhibitor loading dose (clopidogrel 600 mg, ticagrelor 180 mg, or prasugrel 60 mg). Ticagrelor and prasugrel are generally preferred over clopidogrel due to their more potent antiplatelet effects, particularly in high-risk patients, as noted in the 2017 ESC guidelines 1 and 2018 ESC guidelines 1. In patients with high bleeding risk, a shorter DAPT duration of 6 months may be considered, as suggested in the 2018 ESC guidelines 1. Conversely, extended DAPT beyond 12 months may benefit selected patients with high ischemic risk and low bleeding risk, as shown in the PEGASUS-TIMI 54 trial 1. The rationale for DAPT is to prevent stent thrombosis and recurrent cardiovascular events by inhibiting platelet aggregation through two different pathways: aspirin blocks the cyclooxygenase pathway while P2Y12 inhibitors block ADP-mediated platelet activation. Some key points to consider when deciding on the duration of DAPT include:
- Patient's risk of ischemic events
- Patient's risk of bleeding complications
- Presence of comorbidities, such as diabetes or chronic kidney disease
- Use of other medications, such as anticoagulants or non-steroidal anti-inflammatory drugs. It is essential to weigh the benefits and risks of DAPT in each individual patient and to consider the latest guidelines and evidence when making decisions about DAPT duration, as recommended in the 2017 ESC guidelines 1 and 2018 ESC guidelines 1.
From the Research
Recommended Duration of DAPT for STEMI Patients
The recommended duration of Dual Antiplatelet Therapy (DAPT) for patients with ST-Elevation Myocardial Infarction (STEMI) is at least 12 months, as stated in the 2016 updated guidelines from the American College of Cardiology/American Heart Association (ACC/AHA) 2.
Factors Influencing DAPT Duration
The duration of DAPT may vary depending on the patient's risk of bleeding and ischemic events. For patients with a low bleeding risk and high ischemic risk, extended-duration DAPT (up to 30 months) may be recommended 3. On the other hand, for patients with a high bleeding risk and low ischemic risk, shorter-duration DAPT (6 months) may be acceptable 3.
Key Considerations
- The optimal duration of DAPT beyond 1 year is not well established 2.
- Prolonged DAPT may reduce the risk of ischemic events but increases the risk of bleeding 3, 4, 5.
- The decision to extend or shorten DAPT duration should be individualized based on the patient's risk profile 3, 2.
- The use of newer P2Y12 inhibitors, such as prasugrel and ticagrelor, may provide better outcomes compared to clopidogrel 6, 2.
DAPT Regimen
- DAPT typically consists of aspirin and a P2Y12 inhibitor (clopidogrel, ticagrelor, or prasugrel) 6, 2.
- The choice of P2Y12 inhibitor may depend on the patient's risk profile and clinical characteristics 2.
- Discontinuing aspirin rather than the P2Y12 inhibitor may be associated with better outcomes 2.
Clinical Trials and Studies
- The SMART-DATE and DAPT-STEMI trials found that 6-month DAPT and ≥12-month DAPT had comparable net adverse clinical events (NACEs) in patients with event-free MI at six months after durable-polymer DES implantation 5.
- The ISAR-REACT-5 trial found that prasugrel reduced rates of death, myocardial infarction, or stroke at 1 year compared with ticagrelor among patients with ACS undergoing percutaneous coronary intervention 2.