Jérôme Varvat1,2, Aurélie Montmartin2, Magali Epinat1,2, Sandrine Accassat3,4, Arnauld Garcin5, Guorong Li2, Pierre Garnier1,2, Claude Lambert6, Patrick Mismetti1,2,3,5, Nora Mallouk2,3,7. 1. Neurovascular Unit, Saint-Etienne University Hospital Center, North Hospital Saint-Etienne F-42055, France. 2. University of Lyon, UJM - Saint-Etienne, Inserm Sainbiose U1089, Saint-Etienne F-42023, France. 3. Department of Vascular and Therapeutic Medicine, Saint-Etienne University Hospital Center, North Hospital Saint-Etienne F-42055, France. 4. Inserm, CIC1408 Saint-Etienne F-42055, France. 5. Clinical Research, Innovation and Pharmacology Unit, Saint-Etienne University Hospital Center, North Hospital Saint-Etienne F-42055, France. 6. Immunology Department, Saint-Etienne University Hospital Center, North Hospital Saint-Etienne F-42055, France. 7. University of Lyon, UJM-Saint-Etienne, CMES Saint-Etienne F-42023, France.
Abstract
BACKGROUND AND PURPOSE: Biological response to clopidogrel prescribed after a non-cardioembolic ischemic stroke or transient ischemic attack (TIA) has been little studied. The aim of our study (AAPIX) was to assess this response and investigate the agreement between different biological assays in revealing poor responders. METHODS: Patients hospitalized following a non-cardioembolic ischemic stroke or transient ischemic attack (TIA) and prescribed clopidogrel were consecutively included from September 2013 to November 2015 in the Stroke Center of Saint-Etienne Hospital. Blood was drawn after 5 to 8 days of standard-dose clopidogrel. Light transmission aggregometry (LTA) and flow cytometric assays, using vasodilator-stimulated phosphoprotein [VASP] and CD62P, were accomplished for all patients. Transmission electron microscopy (TEM) was performed for a poor clopidogrel-responder and for a patient with discordant platelet assay results (platelet reactivity index (PRI) >50% and maximum platelet aggregation <70%), after activation with adenosine diphosphate (ADP) 10 µM. RESULTS: 72 patients were included. According to LTA, VASP assay and CD62P test results, 65%, 71% and 0% of patients, respectively, had a low response to clopidogrel, indicating poor agreement between these assays. Images of ADP-activated platelet samples from a patient manifesting a low response to clopidogrel and from a patient with discordant platelet assay results showed an ultrastructural pattern typical of activation and a state of slight activation, respectively. CONCLUSIONS: Platelet function results obtained using different assays for patients having experienced a non-cardioembolic ischemic stroke or TIA were discordant. Transmission electron microscopy could be useful in certain clinical contexts when platelet function assay results disagree. AJTR
BACKGROUND AND PURPOSE: Biological response to clopidogrel prescribed after a non-cardioembolic ischemic stroke or transient ischemic attack (TIA) has been little studied. The aim of our study (AAPIX) was to assess this response and investigate the agreement between different biological assays in revealing poor responders. METHODS:Patients hospitalized following a non-cardioembolic ischemic stroke or transient ischemic attack (TIA) and prescribed clopidogrel were consecutively included from September 2013 to November 2015 in the Stroke Center of Saint-Etienne Hospital. Blood was drawn after 5 to 8 days of standard-dose clopidogrel. Light transmission aggregometry (LTA) and flow cytometric assays, using vasodilator-stimulated phosphoprotein [VASP] and CD62P, were accomplished for all patients. Transmission electron microscopy (TEM) was performed for a poor clopidogrel-responder and for a patient with discordant platelet assay results (platelet reactivity index (PRI) >50% and maximum platelet aggregation <70%), after activation with adenosine diphosphate (ADP) 10 µM. RESULTS: 72 patients were included. According to LTA, VASP assay and CD62P test results, 65%, 71% and 0% of patients, respectively, had a low response to clopidogrel, indicating poor agreement between these assays. Images of ADP-activated platelet samples from a patient manifesting a low response to clopidogrel and from a patient with discordant platelet assay results showed an ultrastructural pattern typical of activation and a state of slight activation, respectively. CONCLUSIONS: Platelet function results obtained using different assays for patients having experienced a non-cardioembolic ischemic stroke or TIA were discordant. Transmission electron microscopy could be useful in certain clinical contexts when platelet function assay results disagree. AJTR
Authors: Saskia H Meves; Kay D Schröder; Heinz G Endres; Christos Krogias; Jan C Krüger; Horst Neubauer Journal: Thromb Res Date: 2013-12-07 Impact factor: 3.944
Authors: Jean-Philippe Collet; Thomas Cuisset; Grégoire Rangé; Guillaume Cayla; Simon Elhadad; Christophe Pouillot; Patrick Henry; Pascal Motreff; Didier Carrié; Ziad Boueri; Loic Belle; Eric Van Belle; Hélène Rousseau; Pierre Aubry; Jacques Monségu; Pierre Sabouret; Stephen A O'Connor; Jérémie Abtan; Mathieu Kerneis; Christophe Saint-Etienne; Olivier Barthélémy; Farzin Beygui; Johanne Silvain; Eric Vicaut; Gilles Montalescot Journal: N Engl J Med Date: 2012-11-04 Impact factor: 91.245
Authors: Bo Rong Zhou; Hong Ting Shi; Rong Wang; Min Zhang; Hai Tao Guan; Zi Fan Liu; Yan Hua Deng Journal: J Neurol Date: 2013-10-18 Impact factor: 4.849