title: Prevalence of poor biological response to clopidogrel: a systematic review.
abstract: The existence of poor biological response to clopidogrel has been shown in some patients. Despite the increasing number of studies, this phenomenon remains difficult to quantify. We performed a systematic review to estimate the prevalence of poor biological response to clopidogrel and investigate the factors known to modulate this. An exhaustive search was performed. Altogether 171 publications were identified, providing data for a total of 45,664 subjects. The estimated prevalence of poor biological response to clopidogrel ranged from 15.9% to 49.5% according to the platelet function assay employed. The assays most frequently used were light transmittance aggregometry (LTA), the vasodilator-stimulated phosphoprotein (VASP) assay and the Verifynow® assay. For all these assays, higher cut-off values were associated with a lower prevalence of poor biological response to clopidogrel. However, when choosing a fixed cut-off point for each assay, the prevalence of poor biological response to clopidogrel was highly variable suggesting that other factors could modulate poor biological response to clopidogrel. Finally, none of the studied factors could apparently explain the variability of poor biological response to clopidogrel. This meta-analysis shows that the prevalence of poor biological response depends on the assay employed, the cut-off value and on various unidentified additional factors.
authors.affiliation: Université de Lyon, EA3065, Université Jean Monnet, Saint-Etienne, France. nora.mallouk@chu-st-etienne.fr
authors.forename: Nora
authors.initials: N
authors.lastname: Mallouk
authors.forename: Carine
authors.initials: C
authors.lastname: Labruyère
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Reny
authors.forename: Céline
authors.initials: C
authors.lastname: Chapelle
authors.forename: Michèle
authors.initials: M
authors.lastname: Piot
authors.forename: Pierre
authors.initials: P
authors.lastname: Fontana
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Gris
authors.forename: Xavier
authors.initials: X
authors.lastname: Delavenne
authors.forename: Patrick
authors.initials: P
authors.lastname: Mismetti
authors.forename: Silvy
authors.initials: S
authors.lastname: Laporte
mesh_terms: D000077144:Clopidogrel; D006801:Humans; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D015588:Observer Variation; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D010979:Platelet Function Tests / Q000592:standards / Q000706:statistics & numerical data*; D015995:Prevalence; D058925:Receptors, Purinergic P2Y12 / Q000378:metabolism; D012015:Reference Standards; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D017211:Treatment Failure
chemical_list: C548576:P2RY12 protein, human; D010975:Platelet Aggregation Inhibitors; D058925:Receptors, Purinergic P2Y12; D000077144:Clopidogrel; D013988:Ticlopidine