Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis- CloPidogREl for Primary preVENTION (HOST-PREVENTION)

The investigators will evaluate the efficacy and safety of clopidogrel for primary prevention in patients diagnosed with coronary atherosclerosis on imaging that did not require revascularization therapy.

The trial will test the hypothesis that clopidogrel is beneficial in preventing major adverse cardiovascular and cerebrovascular events (MACCE) in patients with subclinical coronary atherosclerosis identified on imaging.

Coronary artery disease (CAD) is the most prevalent and lethal disease worldwide. Even though various studies have been performed regarding the prevention or treatment of CAD and its related cardiovascular events, the prevalence of CAD and the incidence of cardiovascular events are increasing.

Antiplatelet agents are among the most widely used drugs for preventing cardiovascular events. The efficacy of antiplatelet agents has been extensively proven in secondary prevention for cardiovascular events in CAD patients, and their use has been recommended in current guidelines. However, there is still controversy surrounding the prescription of antiplatelet agents for the primary prevention of cardiovascular events in CAD patients due to their unknown clear efficacy and risk of bleeding complications.

Recent studies reported the limited efficacy of aspirin in old patients, diabetes patients, or patients with cardiovascular events risks. However, the efficacy or safety of antiplatelet therapy in patients with subclinical coronary atherosclerosis has not been thoroughly investigated. These patients are at higher risk of cardiac death or myocardial infarction compared to patients without coronary atherosclerosis.

In this regard, the investigators will evaluate the efficacy and safety of clopidogrel for primary prevention in patients diagnosed with coronary atherosclerosis on imaging that did not require revascularization therapy.

Eligibility Criteria:
Inclusion Criteria:

* Male or female aged ≥40 years
* Patients with subclinical coronary atherosclerosis identified from coronary CT angiography or coronary angiography within 2 years without clinical events after an imaging study
* Without significant coronary artery stenosis (Diameter stenosis \>50%), which needs revascularization
* Agreement to give written informed consent

Exclusion Criteria:

* A history of a diagnosed cardiovascular or cerebrovascular disease (myocardial infarction, heart failure, peripheral artery disease, stroke, transient ischemic attack, carotid artery stenosis\>50%, carotid artery intervention)
* A history of coronary artery intervention or coronary artery bypass graft surgery, which needs chronic maintenance of antiplatelet therapy
* Absolute contraindication or allergy to clopidogrel
* Patients receiving anticoagulants for other comorbidities
* A history of Bleeding diathesis, known coagulopathy, or major bleeding, BARC class ≥3, resulting in the stop of antiplatelet agents
* Planned surgery or intervention which needs to stop antiplatelet agents ≥1 month
* Presence of non-cardiac comorbidity with life expectancy ≤ 5 years at randomization
* Females with pregnancy or breast-feeding
* Patients who are thought to be inappropriate for the trial based on physicians' decision