title: Assessment methods for aspirin-mediated platelet antiaggregation in type 2 diabetic patients: degree of correlation between 2 point-of-care methods.
abstract: OBJECTIVE
  Impaired response to antiplatelet therapy in diabetic patients results in a higher incidence of drug-eluting stent thrombosis. This study determined the prevalence of high on-aspirin (AS) platelet reactivity in type 2 diabetic patients treated with percutaneous coronary intervention (PCI) using the VerifyNow Aspirin Assay (VN) and platelet function analyzer PFA-100 (PFA-100) and analyzed the correlation between both methods.
  
  
  METHODS
  Type 2 diabetic patients (100) with non-ST-elevation acute coronary syndrome who underwent PCI and Xience V drug-eluting stent implantation were included in this study. After PCI, platelet antiaggregation mediated by acetylsalicylic acid was assessed by VN and PFA-100. The degree of correlation and concordance was then determined.
  
  
  RESULTS
  When assayed with VN, 7% of the patients were nonresponders to aspirin (aspirin reaction units >550), and when assayed with PFA-10, 41% were nonresponders (closure time <193 seconds). Of the patients, 4% were nonresponders to aspirin according to VN but were sensitive to aspirin according to PFA-100, and 38% were sensitive to aspirin according to VN and nonresponders according to PFA-100. Overall, 55% of the patients were aspirin-sensitive in both methods. The Spearman's coefficient between VN and PFA-100 results was r = 0.09 (P = 0.35). The kappa index value was 0.0062 (P = 0.91).
  
  
  CONCLUSIONS
  There is no concordance or correlation between the VN and PFA-100 results. Therefore, the use of these analyses should be restricted to clinical research, which limits its application in clinical practice.
authors.affiliation: *Department of Cardiology, Hospital Universitario Virgen del Rocio, Seville, Spain; and Departments of †Internal Medicine, ‡Investigation, and §Cardiology, Hospital Universitario Virgen de Valme, Seville, Spain.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Cubero Gómez
authors.forename: María A
authors.initials: MA
authors.lastname: Navarro Puerto
authors.forename: Juan
authors.initials: J
authors.lastname: Acosta Martínez
authors.forename: María I
authors.initials: MI
authors.lastname: De Mier Barragán
authors.forename: Pastor L
authors.initials: PL
authors.lastname: Pérez Santigosa
authors.forename: Francisco
authors.initials: F
authors.lastname: Sánchez Burguillos
authors.forename: Francisco
authors.initials: F
authors.lastname: Molano Casimiro
authors.forename: Luis
authors.initials: L
authors.lastname: Pastor Torres
mesh_terms: D001241:Aspirin / Q000494:pharmacology / Q000627:therapeutic use*; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D008297:Male; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D010979:Platelet Function Tests; D019095:Point-of-Care Systems; D011446:Prospective Studies; D018709:Statistics, Nonparametric
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin