Comparison of Clopidogrel-based Antiplatelet Agent Treatment and Aspirin Plus Low Dose Rivaroxaban Therapy

Optimal Strategy for Treatment of Atherosclerotic Cardiovascular Disease - Comparison of Clopidogrel-based Antiplatelet Agent Treatment Versus Aspirin Plus Low Dose Rivaroxaban Therapy

The study aims to conduct a randomized controlled trial among adults aged 19 years or older who have experienced acute myocardial infarction at least one year prior, or who have other comorbidities such as peripheral arterial disease or multiple cardiovascular diseases, and have consented to participate in the study. Participants will be randomly assigned to either a group that maintains antiplatelet therapy with aspirin and clopidogrel or clopidogrel alone, or a group that maintains combined antiplatelet and anticoagulant therapy with aspirin and low-dose rivaroxaban in a 1:1 ratio. The study aims to demonstrate that maintaining clopidogrel-based antiplatelet therapy is not clinically inferior to maintaining combined therapy with aspirin and low-dose rivaroxaban.

Rupture of atherosclerotic plaques and resulting thrombotic or embolic events can lead to myocardial infarction, stroke, and death. Particularly after vascular interventions such as percutaneous coronary intervention, stent implantation, or peripheral vascular interventions, it takes more than a year for the damaged endothelial cells to heal completely, leading to frequent thrombotic complications. In addition, clinically undiagnosed atrial fibrillation, stroke caused by thrombosis formation due to venous damage, myocardial infarction, deep vein thrombosis, and pulmonary embolism may occur. Therefore, drug therapy to prevent thrombosis is necessary for these patients, and many studies have been conducted to determine the optimal treatment.

Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is essential for treating patients after percutaneous coronary intervention (PCI). DAPT can minimize ischemic events not only in stent lesions but also in non-reperfused lesions of the coronary artery. However, DAPT increases the risk of bleeding, so a treatment strategy is needed to minimize ischemic events while reducing the risk of bleeding by using dual antiplatelet therapy for a short time after the procedure, administering antiplatelet drugs differently depending on the bleeding risk. In particular, in patients at high risk of bleeding (HBR), the side effects of bleeding due to long-term antiplatelet therapy are closely related to long-term survival, making this issue even more important. Compared to traditional aspirin use, the use of clopidogrel has been reported to reduce mortality, myocardial infarction, stroke, and hospitalization due to acute coronary artery disease while reducing bleeding complications.

In addition, a study has reported that combining low-dose anticoagulants with aspirin as a thromboprophylactic agent for stable atherosclerotic patients who were previously treated only with antiplatelet drugs reduces mortality and has superior effects on the prevention of myocardial infarction and stroke compared to aspirin alone. Aspirin and low-dose rivaroxaban combination therapy has been approved for use in patients with multivessel CAD who are over 65 years of age and have experienced acute myocardial infarction for more than one year, as well as patients with peripheral arterial disease (PAD) (history of PTA or bypass, history of foot/leg amputation, intermittent claudication with ABI <0.9, or over 50% stenosis in peripheral arteries, or over 50% stenosis in coronary arteries or previous coronary stent implantation) who have one of the two conditions: a history of acute myocardial infarction for over one year or multivessel CAD.

Ultimately, studies comparing clopidogrel and low-dose rivaroxaban and aspirin combination therapy in similar patient populations have shown the superiority of each treatment strategy, but no studies have compared the two treatment strategies. If clopidogrel monotherapy is more convenient to take, has better compliance, and is not less effective than low-dose rivaroxaban and aspirin combination therapy, it may be considered as a more convenient treatment strategy for many patients.

Inclusion Criteria:

• Patients over 65 years of age who have experienced acute myocardial infarction and have multivessel coronary artery disease (CAD) that has been present for over one year
• Patients who have peripheral arterial disease (history of PTA or bypass, history of foot/leg amputation, intermittent claudication with ABI <0.9 or over 50% stenosis in peripheral arteries, or over 50% stenosis in coronary arteries or previous coronary stent implantation) and have a history of acute myocardial infarction for over one year or have one of the two conditions: multivessel CAD.
• Subject is able to verbally confirm understandings of risks, benefits and treatment, and he/she or his/her legally authorized representative provides written informed consent prior to study

Exclusion Criteria:

• History of serious hypersensitivity reactions to aspirin, clopidogrel, or prasugrel.
• Patients with coagulation disorders or liver diseases related to coagulation, as well as patients with moderate (Child Pugh B) and severe (Child Pugh C) liver dysfunction.
• Severe renal impairment with a creatinine clearance less than 15 mL/min.
• Patients who require long-term combination therapy with other anticoagulants such as unfractionated heparin (UFH), low molecular weight heparin (enoxaparin, dalteparin, etc.), heparinoids (fondaparinux, etc.), oral anticoagulants (warfarin, apixaban, dabigatran, etc.).
• In cases of active clinical bleeding at the time of study registration.
• Patients who require discontinuation of antiplatelet therapy for more than 3 months due to surgery or procedure
• Individuals with an expected lifespan of less than 3 years due to reasons other than cardiovascular disease.
• Concomitant use of the following contraindicated drugs: other P2Y12 inhibitors (prasugrel or ticagrelor); cytochrome P450 2C19 inhibitors (fluoxetine, fluvoxamine, or voriconazole); probenecid; high-dose methotrexate (≥15 mg/week); lithium.
• Pregnant or breastfeeding women.
• Inability to provide informed consent