title: Variability in platelet aggregation following sustained aspirin and clopidogrel treatment in patients with coronary heart disease and influence of the 807 C/T polymorphism of the glycoprotein Ia gene.
abstract: A broad variability in patient response to dual antiplatelet treatment has been described during the first month of treatment. Data on platelet function profiles in patients on dual antiplatelet therapy for a more sustained period are limited. Whether gene sequence variations of the glycoprotein Ia/IIa receptor influence platelet aggregation in these patients is also unknown. The aim of this study was to characterize platelet aggregation profiles in patients on dual antiplatelet treatment (aspirin plus clopidogrel) for >1 month and to assess whether these may be influenced by the C807T polymorphism of the glycoprotein Ia gene. We included 82 patients, who were divided into 2 groups: carriers (CT + TT genotypes; n = 51) and noncarriers (CC genotype; n = 31) of the mutant T allele. Platelet aggregation was assessed using light transmittance aggregometry after stimuli with adenosine diphosphate (20 micromol/L), collagen (6 microg/ml), and epinephrine (20 micromol/L). A significant variability in the distribution of platelet aggregation was observed in the overall study population, as well as in carriers and noncarriers of the T allele. T allele carriers had increased platelet aggregation compared with noncarriers after stimuli with adenosine diphosphate, collagen, and epinephrine (p <0.05 for all platelet aggregation assays). Thus, platelet aggregation varied significantly in patients on long-term dual antiplatelet treatment and was increased in T allele carriers of the 807C/T polymorphism of the glycoprotein Ia gene. These findings may contribute to the increased ischemic risk observed in these patients.
authors.affiliation: Division of Cardiology, University of Florida, Jacksonville, Florida, USA. dominick.angiolillo@jax.ufl.edu
authors.forename: Dominick J
authors.initials: DJ
authors.lastname: Angiolillo
authors.forename: Antonio
authors.initials: A
authors.lastname: Fernandez-Ortiz
authors.forename: Esther
authors.initials: E
authors.lastname: Bernardo
authors.forename: Celia
authors.initials: C
authors.lastname: Ramírez
authors.forename: Ugo
authors.initials: U
authors.lastname: Cavallari
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Trabetti
authors.forename: Manel
authors.initials: M
authors.lastname: Sabaté
authors.forename: Pilar
authors.initials: P
authors.lastname: Jimenez-Quevedo
authors.forename: Rosana
authors.initials: R
authors.lastname: Hernández
authors.forename: Raul
authors.initials: R
authors.lastname: Moreno
authors.forename: Javier
authors.initials: J
authors.lastname: Escaned
authors.forename: Fernando
authors.initials: F
authors.lastname: Alfonso
authors.forename: Camino
authors.initials: C
authors.lastname: Bañuelos
authors.forename: Marco A
authors.initials: MA
authors.lastname: Costa
authors.forename: Theodore A
authors.initials: TA
authors.lastname: Bass
authors.forename: Pier Franco
authors.initials: PF
authors.lastname: Pignatti
authors.forename: Carlos
authors.initials: C
authors.lastname: Macaya
mesh_terms: D000328:Adult; D000483:Alleles; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D000077144:Clopidogrel; D003327:Coronary Disease / Q000188:drug therapy*; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D006801:Humans; D039421:Integrin alpha2 / Q000187:drug effects / Q000235:genetics*; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects* / Q000235:genetics; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011110:Polymorphism, Genetic; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D039421:Integrin alpha2; D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin; D004837:Epinephrine