Antiplatelet Therapy

Antiplatelet therapy inhibits enzymes or receptors in platelets and thereby prevents platelet aggregation, which most commonly occurs following endothelial injury in the arteries.

Infographic illustrating atrial fibrillation with a thrombus in the left atrial appendage and a warning that antiplatelet therapy is not recommended for thromboembolism prevention.

Antiplatelet therapy is classified according to the enzyme or receptor it inhibits. The basic classification of antiplatelet therapy includes:

Cyclooxygenase inhibitor (COX-1)

Aspirin (Anopyrin)

P2Y12 inhibitors

Clopidogrel (Trombex, Plavix)
Prasugrel (Efient)
Ticagrelor (Brilique)

IIb/IIIa inhibitors

Abciximab (ReoPro)
Eptifibatide (Integrilin)

In clinical practice, Aspirin and Clopidogrel are used most frequently.

The main indication for antiplatelet therapy is the prevention and treatment of atherosclerotic arterial cardiovascular diseases:

Acute coronary syndrome
Ischaemic stroke (non-embolic)
Peripheral arterial disease

Antiplatelet therapy prevents the formation of a platelet thrombus, which develops following endothelial injury of an artery.

In atrial fibrillation (AF), however, a fibrin-rich thrombus forms due to blood stasis, most commonly in the left atrial appendage,
therefore, antiplatelet therapy does not prevent thrombus formation in the left atrial appendage in AF.

Antiplatelet therapy in AF does not prevent thromboembolism and is not an alternative to anticoagulation therapy.

Risk of Thromboembolism and Atrial Fibrillation	Class
Antiplatelet therapy is not recommended for the prevention of thromboembolism in atrial fibrillation (AF).	III
For the prevention of thromboembolism in patients with AF, the combination of anticoagulation and antiplatelet therapy is not recommended.	III