From the Guidelines
Dual antiplatelet therapy (DAPT) is indicated for all patients with acute coronary syndrome (ACS) to reduce the risk of recurrent cardiovascular events and stent thrombosis, with ticagrelor or prasugrel recommended in preference to clopidogrel in patients undergoing percutaneous coronary intervention (PCI) 1. The standard DAPT regimen consists of aspirin (81-325 mg daily, typically 81 mg for long-term use) plus a P2Y12 inhibitor.
- For most ACS patients, the preferred P2Y12 inhibitors are ticagrelor (90 mg twice daily) or prasugrel (10 mg daily, reduced to 5 mg daily in patients ≥75 years or <60 kg) 1.
- Clopidogrel (75 mg daily) is an alternative when ticagrelor or prasugrel are contraindicated. Key considerations for DAPT duration include:
- DAPT should be continued for at least 12 months in most ACS patients, regardless of whether they received medical management alone or underwent PCI 1.
- In high-risk patients with low bleeding risk, DAPT may be extended beyond 12 months, while in patients with high bleeding risk, a shorter duration (6 months) may be considered 1. The mechanism of DAPT involves inhibiting platelet aggregation through two complementary mechanisms:
- Aspirin irreversibly inhibits cyclooxygenase-1.
- P2Y12 inhibitors block ADP-mediated platelet activation, providing more comprehensive protection against thrombotic events during the high-risk period following ACS. Overall, the use of DAPT in patients with ACS is supported by strong evidence from recent guidelines, including the 2025 ACC/AHA/ACEP/NAEMSP/SCAI guideline for the management of patients with acute coronary syndromes 1.
From the FDA Drug Label
1.1 Acute Coronary Syndrome (ACS) 1.2 Recent MI, Recent Stroke, or Established Peripheral Arterial Disease The FDA drug label does not answer the question.
From the Research
Indication for Dual Antiplatelet Therapy (DAPT) in Acute Coronary Syndrome (ACS)
The indication for dual antiplatelet therapy (DAPT) in patients with acute coronary syndrome (ACS) is to reduce the risk of thrombotic complications associated with atherosclerotic cardiovascular diseases 2. DAPT combines two antiplatelet agents, typically aspirin and a P2Y12 inhibitor (clopidogrel, ticagrelor, or prasugrel), to decrease cardiovascular event rates after ACS 3.
Duration of DAPT
The optimal duration of DAPT in patients with ACS is still a topic of debate. Studies have shown that short-term DAPT (≤3 months or 6 months) does not increase ischemic outcomes compared to long-term DAPT (12 months and >12 months) 4. In fact, abbreviated DAPT was associated with comparable rates of net adverse clinical events and major adverse cardiovascular events to a DAPT duration of 12 months in patients with high bleeding risk undergoing percutaneous coronary intervention due to ACS 5.
Factors Influencing DAPT Duration
The decision to extend or shorten DAPT duration should be based on patient characteristics, including the risk of bleeding and myocardial ischemia 3. Patients at high risk of bleeding may benefit from shorter DAPT duration, while those at high risk of ischemia may require longer DAPT duration 6. The use of newer generation drug-eluting stents (DES) may also allow for shorter DAPT duration 4.
Key Considerations
- DAPT reduces cardiovascular event rates after ACS, but increases bleeding risk 2, 3.
- The optimal DAPT duration in patients with ACS is still uncertain, but short-term DAPT may be safe and effective in certain patients 5, 4.
- Patient characteristics, including bleeding risk and ischemic risk, should guide DAPT duration decisions 3, 6.
- Newer generation DES may allow for shorter DAPT duration 4.