title: Monitoring ASA and P2Y12-specific platelet inhibition--comparison of conventional (single) and multiple electrode aggregometry.
abstract: OBJECTIVE
  Several platelet function test systems exist for the evaluation of the platelet inhibitory effect in patients on P2Y12 inhibitors and/or acetylsalicylic acid (ASA, aspirin) therapy. Studies comparing different available assays found only a poor correlation. The objective of the present study was to evaluate the correlation and agreement between single electrode (SEA) and multiple electrode (MEA) aggregometry.
  
  
  RESULTS
  In whole blood arachidonic acid (AA) and adenosine diphosphate (ADP)-induced platelet aggregation was measured simultaneously using SEA (Chrono-Log) and MEA (Multiplate). We analyzed a total of 226 measurements taken from 58 patients on single ASA therapy or dual antiplatelet therapy with ASA and a thienopyridine. A cut-off value for clopidogrel/prasugrel high on-treatment platelet reactivity (HPR) of > 47 units (U) was chosen for MEA testing using hirudin and > 5 Ohm for SEA with citrate anticoagulated blood samples. The respective cut-off values for ASA HPR were > 30 U for the MEA assay and > 1 Ohm for SEA testing. There was a good correlation of the prevalence of thienopyridine-HPR in both whole blood assays (Spearman rank correlation coefficient r = 0.698) and a good inter-rate accordance (Cohen's Kappa statistic κ = 0.648). For AA-induced aggregation, the correlation of the results obtained was significant (r = 0.536; p < 0.001) and detecting ASA-HPR revealed a moderate (κ = 0.482) correlation between both impedance aggregometry assays.
  
  
  CONCLUSIONS
  Platelet function testing using SEA and MEA provided both good accordance and correlation and therefore study results obtained by these two assays similarly enabled the detection of HPR of thienopyridine (and ASA) therapy.
authors.affiliation: Cardiovascular Center.
authors.forename: Jan-Christopher
authors.initials: JC
authors.lastname: Krüger
authors.forename: Saskia H
authors.initials: SH
authors.lastname: Meves
authors.forename: Kaffer
authors.initials: K
authors.lastname: Kara
authors.forename: Andreas
authors.initials: A
authors.lastname: Mügge
authors.forename: Horst
authors.initials: H
authors.lastname: Neubauer
mesh_terms: D000368:Aged; D001241:Aspirin / Q000494:pharmacology / Q000627:therapeutic use*; D001792:Blood Platelets / Q000187:drug effects*; D004566:Electrodes; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010979:Platelet Function Tests / Q000379:methods*; D058921:Purinergic P2Y Receptor Antagonists / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D058921:Purinergic P2Y Receptor Antagonists; D001241:Aspirin
keywords: Aspirin; clopidogrel; impedance aggregometry; multiplate; multiple electrode aggregometry; platelet function test; residual platelet reactivity; whole blood platelet aggregation