Aspirin and clopidogrel: Efficacy, treatment, and resistance in coronary artery disease

Abstract

Oral antiplatelet therapy is a key element of the continuously evolving treatment of acute coronary syndromes. As part of this evolution, resistance to oral antiplatelet therapy has emerged as a new challenge adversely affecting patients' clinical risk and outcome. This review addresses the role of two oral antiplatelet therapy agents, aspirin and clopidogrel, their mechanism of action, and the evidence supporting their use in the setting of coronary artery disease. Unfortunately, clinically relevant resistance to aspirin and clopidogrel exists. Resistance may indicate a higher risk for major adverse events. An established safe and reliable treatment alternative is lacking at this point; further research is needed to evaluate the efficacy of any alternative treatments that can be offered to decrease cardiovascular risk and improve clinical outcomes.

Abbreviations

ADP =: adenosine diphosphate;
CAPRIE =: Clopidogrel vs. Aspirin in Patients at Risk of Ischaemic Events;
CHARISMA =: Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance;
COX =: cyclooxygenase;
CREDO =: Clopidogrel for the Reduction of Events During Observation;
CURE =: the Clopidogrel in Unstable angina to prevent Recurrent Events;
GP =: glycoprotein;
LDL =: low-density lipoprotein;
NO =: nitrous oxide;
ISIS-2 =: Second International Study of Infarct Survival;
PG =: prostaglandin;
PGI₂ =: prostacyclin;
TX =: thromboxane;
TXA2 =: thromboxane A2.