Aspirin and clopidogrel hyporesponsiveness and nonresponsiveness in patients with coronary artery stenting

Figures & data

Table 1 Mechanisms of “resistance” to aspirin and clopidogrel

Non compliance

Poor absorption

Sub optimal dose

Smoking

Genetic polymorphism

Thrombocytosis

Concomitant medication

Co-morbid conditions

Severe coronary artery disease

Table 2 Definition of aspirin and clopidogrel hyporesponsiveness, nonresponsiveness or “resistance”

Aspirin		Clopidogrela
	Reference	Responders	Hyporesponder	Resistant	Reference
ARU > 550 (lack of ASA-induced platelet dysfunction)	39	>30%	<10%–29%	<10%	^Citation28
C/EPI-CT < 193 seconds	14	>40%		<40%	^Citation27
C/ADP-CT < 121 seconds	13	>30%	<10%–30%	10%	^Citation29
		>10%		<10%	^Citation30

^a Response (%) of platelet inhibition by clopidogrel.

Abbreviations: ARU, aspirin reaction units; C/EPI-CT, collagen/epinephrine closure time; C/ADP-CT, collagen/ADP closure time; ASA, aspirin.

Figure 1 Understanding platelet function testing.

Abbreviations: AA, arachidonic acid; PRU, P2Y12 reaction units; ARU, aspirin reaction units; TXA2, thromboxane A₂.

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