Effects of ADP-receptor antagonism beyond traditional inhibition of platelet aggregation

Area of Science:

• Cardiovascular Medicine
• Pharmacology
• Vascular Biology

Background:

• Atherothrombosis, involving plaque rupture and thrombus formation, underlies major cardiovascular events like heart attack and stroke.
• Vascular inflammation plays a critical role in atherosclerosis and atherothrombosis.
• Platelets are key mediators of vascular inflammation.

Purpose of the Study:

• To evaluate the efficacy of clopidogrel compared to aspirin in preventing atherothrombotic events.
• To investigate the effects of clopidogrel on markers of vascular inflammation.
• To explore potential additional mechanisms of action for clopidogrel.

Main Methods:

• Systematic review of existing evidence on clopidogrel and aspirin in atherothrombosis.
• Analysis of studies measuring inflammatory markers in patients treated with clopidogrel or aspirin.
• Examination of data on clopidogrel's effects on anticoagulation and vasoconstriction.

Main Results:

• Clopidogrel demonstrates superior efficacy to aspirin in preventing ischemic stroke, myocardial infarction, and vascular death in symptomatic atherosclerosis.
• Combination therapy with clopidogrel and aspirin provides incremental benefits in coronary atherothrombosis.
• Clopidogrel, but not aspirin alone, significantly reduces vascular inflammation markers across cerebrovascular, coronary, and peripheral circulations.
• Clopidogrel exhibits potential anticoagulant effects and may inhibit arterial vasoconstriction.

Conclusions:

• Clopidogrel is a highly effective antiplatelet agent for managing symptomatic atherosclerosis, offering benefits beyond aspirin.
• Clopidogrel's ability to reduce vascular inflammation and its potential anticoagulant and anti-vasoconstrictive properties contribute to its protective effects.
• These broader actions should be considered when optimizing antiplatelet therapy regimens.