Assessment of clopidogrel non-response by the PFA-100 system using the new test cartridge INNOVANCE PFA P2Y.
Until now, the PFA-100 system has been considered unsuitable for monitoring clopidogrel efficacy. The authors evaluated platelet function in peripheral arterial occlusive disease (PAOD) patients using a new PFA-100(R) test cartridge (product name: INNOVANCE PFA P2Y*) specifically designed for this purpose. Twenty-two stable PAOD patients on antithrombotic therapy with clopidogrel alone (n = 22) and 18 patients undergoing a peripheral catheter intervention, preliminarily treated with 100 mg/day of aspirin followed by co-administration of clopidogrel (loading dose 300 mg, maintenance dose 75 mg/day), were enrolled in this study. Defining non-responsiveness to clopidogrel as an aggregation response within the reference range (90% central interval), four (18.2%) non-responders using light transmittance aggregometry (LTA) induced by 5 microM adenosine diphosphate (ADP) and six (27.3%) non-responders using LTA induced by 2 microM ADP (LateAggr >72.1% and >42.9%, respectively) were identified. INNOVANCE PFA P2Y* determined six (27.3%) non-responders (CT < 87 s). Agreement between the two aggregometry assays and INNOVANCE PFA P2Y* on the definition of clopidogrel response and non-response exceeded 70%. Only three patients were uniformly identified as clopidogrel non-responders by all three assays. When clopidogrel was co-administered with aspirin, two (11.1%) non-responders to clopidogrel were detected with INNOVANCE PFA P2Y*, whereas ADP-induced LTA found all patients to be responsive. INNOVANCE PFA P2Y* appears to be suitable for monitoring the effect of clopidogrel on platelet function. Its sensitivity in detecting responsiveness or non-responsiveness to clopidogrel is comparable to ADP-induced LTA. Additional prospective studies are needed to clarify the clinical relevance of the test results and classification obtained with INNOVANCE PFA P2Y*.
Linnemann
Birgit
B
Division of Vascular Medicine, Department of Internal Medicine, JW Goethe University Hospital Frankfurt/Main, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany. Birgit.Linnemann@kgu.de
Schwonberg
Jan
J
Rechner
Andreas R
AR
Mani
Helen
H
Lindhoff-Last
Edelgard
E
D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy*; D001241:Aspirin / Q000008:administration & dosage; D001792:Blood Platelets / Q000473:pathology / Q000502:physiology; D002406:Catheterization, Peripheral / Q000379:methods; D000077144:Clopidogrel; D003935:Diagnostic Techniques, Cardiovascular / Q000295:instrumentation*; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage; D006487:Hemostasis / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D011379:Prognosis; D011933:Reagent Kits, Diagnostic; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D017211:Treatment Failure
D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D011933:Reagent Kits, Diagnostic; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin