Clinical importance of aspirin and clopidogrel resistance

Table 3 Clinical studies based on optical aggregometry combined with another method

Study	Method	Patient population	Dosage	Adjunct antiplatelet therapy	No. of patients (clopidogrel sensitive/clopidogrel resistant)	Outcome measures	Result
Lev et al[62]	Optical aggregometry, RPFA	Elective PCI	300 mg clopidogrel followed by 75 mg daily	No	150 (114/36)	Markers of myonecrosis	Myonecrosis occurred more frequently in clopidogrel-resistant vs clopidogrel-sensitive patients (32.4% vs 17.3%, P = 0.06)
Bliden et al[101]	Optical aggregometry, TEG	PCI	Previously 75 mg daily, 300-600 mg loading dose followed by 75 mg daily	325 mg	100	Cardiovascular event/revascularisation	Patients receiving chronic clopidogrel therapy who exhibit high on-treatment ADP-induced platelet aggregation are at increased risk for postprocedural ischemic events
Gurbel et al[102]	Optical aggregometry, TEG	PCI	300-600 mg loading dose followed by 75 mg daily	325 mg aspirin	192 (154 patients without and 38 patients with ischaemic events)	Cardiovascular outcome/revascularisation	Posttreatment ADP-induced aggregation by LTA (63% ± 12% vs 56% ± 15%, P = 0.02) was significantly higher) in patients with events (n = 38)
Matetzky et al[59]	Optical aggregometry, cone and platelet analyzer	PCI	300 mg clopidogrel followed by 75 mg daily	300 mg of aspirin followed by 200 mg/d	60 (patients were stratified into 4 quartiles)	Cardiovascular event	Whereas 40% of patients in the first quartile sustained a recurrent cardiovascular event, only 1 patient (6.7%) in the second quartile and none in the third and fourth quartiles suffered a cardiovascular event (P = 0.007)

ADP: Adenosine diphosphate.