萝莉社

People are being asked to participate in this study because they have a stent in their heart artery and are currently taking blood-thinning medications as part of standard of care. In particular, they are taking two blood-thinning medications, which include baby aspirin plus either Prasugrel (Effient) or Ticagrelor (Brilinta). These blood-thinning medications prevent blood cells, called platelets, from sticking together, which help to prevent clots and heart attacks. While these medications are effective at preventing stents from clotting, they also increase the risk of bleeding. To reduce the risk of bleeding while still protecting the heart, doctors sometimes use a strategy called “de-escalation” of blood thinning medications. There are different ways of de-escalating blood thinning medications, which can include switching to a lower dose of the stronger blood thinner called Prasugrel (Effient) or switching to a less potent blood thinner called Clopidogrel (Plavix). With both approaches, patients would continue to take daily aspirin. Research shows that de-escalation can lower the risk of bleeding without increasing the risk of stent clotting or heart attacks. However, there are not many studies which have compared the blood thinning effects of a lower dose of Prasugrel versus Clopidogrel. Therefore, the purpose of this study is to compare how a lower dose of Prasugrel or a standard dose of Clopidogrel will work on platelets.

Inclusion criteria:

1. Patients who have undergone PCI and are on maintenance treatment with DAPT, consisting of low-dose aspirin (81mg qd) with either prasugrel (10 mg qd) or ticagrelor (90 mg bid) as part of standard of care. In particular, patients who underwent PCI in the setting of an acute coronary syndrome will be eligible for randomization after ≥90 days post-PCI, while patients who underwent PCI in the setting of a chronic coronary syndrome ≥30 days post-PCI.
2. Age ≥18 years
3. Provide written informed consent.

Exclusion criteria:

1. Prior history of stent thrombosis
2. Prior cerebrovascular event
3. PCI within 30 days
4. Predicted poor metabolizer of clopidogrel based on CYP2C19 genotyping (e.g., *2/*2 or *3/*3),
5. On treatment with any oral anticoagulant (vitamin K antagonists, dabigatran, rivaroxaban, apixaban, edoxaban) or chronic low-molecular-weight heparin (at venous thrombosis treatment, not for prophylaxis)
6. Hemodynamic instability
7. Hypersensitivity to Aspirin, Clopidogrel, or Prasugrel
8. Known hematologic malignancies or thrombocytopenia (platelet count <80x10⁶/mL)
9. Known hemoglobinopathies or anemia (hemoglobin <9 g/dL)
10. Pregnant and breastfeeding women [women of childbearing age must use reliable birth control (i.e., oral contraceptives) while participating in the study].