Current status of high on-treatment platelet reactivity in patients with coronary or peripheral arterial disease: Mechanisms, evaluation and clinical implications

Table 1 Common platelet function assays

Test	LTA	VASP	VerifyNow
Function	Increase in light transmittance	Flow cytometric measurement of VASP phosphorylation	Measurement of platelet-induced aggregation to fibrinogen-coated beads
Receptor	P2Y1 and P2Y12	P2Y12	P2Y12
Results	MPA	PRI	PRU
Cut-off value	> 46%	> 50%	230-240

LTA: Light transmission aggregometry; VASP: Vasodilator-stimulated phosphoprotein phosphorylation; MPA: Maximal platelet aggregation; PRI: Platelet reactivity index; PRU: P2Y12 reaction units.

Table 2 Highlighted multicenter randomized control trials investigating platelet function tests-guided antiplatelet therapy

Study	Gravitas	Arctic	Trigger-PCI
Study population (n)	2214	2440	423
PFT assay	VerifyNow	VerifyNow	VerifyNow
High-dose clopidogrel	100%	80%	-
High-dose Aspirin	-	45%	-
Prasugrel	-	12%	100%
Results (primary endpoint)	2.3% vs 2.3%	31.1% vs 34.6%	0.0% vs 0.5%

PFT: Platelet function tests; PCI: Percutaneous coronary intervention.