What is the role of dual antiplatelet therapy (DAPT) for patients post percutaneous coronary intervention (PCI) with coronary stent placement?

From the Guidelines

Dual antiplatelet therapy (DAPT) should be given for at least 12 months after drug-eluting stent (DES) implantation for acute coronary syndrome (ACS) patients, with options including clopidogrel 75 mg daily, prasugrel 10 mg daily, and ticagrelor 90 mg twice daily 1. The goal of DAPT is to prevent local thrombotic complications related to stent implantation and to reduce systemic atherothrombotic events. For patients receiving a stent during PCI for ACS, P2Y12 inhibitor therapy should be given for at least 12 months, with the choice of P2Y12 inhibitor depending on patient risk factors and bleeding risk. Some key points to consider when determining the duration of DAPT include:

• The type of stent used (DES or bare metal stent)
• The patient's risk of bleeding and ischemic events
• The presence of any contraindications to P2Y12 inhibitors
• The patient's ability to tolerate DAPT without bleeding complications The 2016 ACC/AHA guideline update recommends at least 12 months of DAPT after DES implantation for ACS patients, with the option to extend DAPT beyond 12 months in patients who have tolerated it without bleeding complications and are not at high bleeding risk 1. In terms of specific P2Y12 inhibitors, ticagrelor or prasugrel are preferred over clopidogrel for maintenance therapy in ACS patients undergoing PCI, if no contraindications exist 1. It's also important to note that premature discontinuation of DAPT increases the risk of stent thrombosis, which can be catastrophic. Overall, the decision to extend or shorten DAPT duration should be individualized based on patient risk factors and clinical presentation. Some of the key factors that influence the decision to extend DAPT include:
• Patient's risk of ischemic events
• Patient's risk of bleeding complications
• Type of stent used
• Patient's ability to tolerate DAPT without bleeding complications
• Presence of any contraindications to P2Y12 inhibitors The 2018 ACC/AHA versus ESC guidelines on DAPT also provide recommendations for DAPT duration in patients undergoing PCI, including those with ACS 1. These guidelines recommend at least 12 months of DAPT for ACS patients undergoing PCI, with the option to extend DAPT beyond 12 months in patients who have tolerated it without bleeding complications and are not at high bleeding risk. In summary, DAPT should be given for at least 12 months after DES implantation for ACS patients, with the option to extend DAPT beyond 12 months in patients who have tolerated it without bleeding complications and are not at high bleeding risk 1.

From the FDA Drug Label

Prasugrel tablets are a P2Y12 platelet inhibitor indicated for the reduction of thrombotic cardiovascular events (including stent thrombosis) in patients with acute coronary syndrome who are to be managed with percutaneous coronary intervention (PCI) The population treated with prasugrel was 27 to 96 years of age, 25% female, and 92% Caucasian. All patients in the TRITON-TIMI 38 study were to receive aspirin.

Dual Antiplatelet Therapy is indicated for patients with acute coronary syndrome who are to be managed with PCI, including those with unstable angina or non-ST-elevation myocardial infarction (NSTEMI) and those with ST-elevation myocardial infarction (STEMI) when managed with either primary or delayed PCI.

• The standard regimen includes aspirin and a P2Y12 platelet inhibitor such as prasugrel.
• The use of dual antiplatelet therapy is supported by clinical trials, including TRITON-TIMI 38, which demonstrated a reduction in thrombotic cardiovascular events in patients treated with prasugrel and aspirin compared to those treated with clopidogrel and aspirin 2 2.

From the Research

Dual Antiplatelet Therapy for Post PCI Coronary Stent

• Dual antiplatelet therapy (DAPT) is used to reduce ischemic and thrombotic events after percutaneous coronary intervention (PCI) 3.
• The duration of DAPT has been a topic of discussion, with initial guidelines recommending 12-month duration after PCI, but newer studies suggesting that shorter durations may be sufficient in certain populations 3, 4.
• Two main strategies have been employed to reduce bleeding concerns: (1) aspirin monotherapy after a short-duration DAPT, and (2) P2Y12 inhibitor monotherapy after a short-duration DAPT 3, 4.
• Studies have shown that P2Y12 blocker monotherapy can reduce major bleeding by 50-60% compared to DAPT, without a significant increase in ischemic outcomes 4.
• The choice of monotherapy after PCI depends on the patient's risk profile, with aspirin monotherapy preferred in low-risk patients and P2Y12 inhibitor monotherapy preferred in intermediate- to high-risk patients 3.

Antiplatelet Therapy Regimens

• DAPT with aspirin and a P2Y12 inhibitor (such as clopidogrel) is commonly used after PCI 5, 6.
• Prasugrel, another thienopyridine, is more potent and faster acting than clopidogrel, and is often used in cases of acute coronary syndrome during PCI 6.
• Ticagrelor and cangrelor are new antiplatelet agents that are undergoing clinical trials 6.
• Triple drug therapy, including cilastozol, is reserved for selected thrombotic lesions 6.

Duration of Antiplatelet Therapy

• The duration of DAPT after PCI is typically kept as short as clinically acceptable, with aspirin monotherapy administered thereafter 4.
• However, some studies suggest that longer durations of DAPT may be beneficial in certain populations, such as those with acute coronary syndrome 7.
• The optimal duration of antiplatelet therapy after PCI remains a topic of debate, with ongoing studies aiming to clarify the role of long-term dual oral antiplatelet therapy in preventing ischemic events 7.