BACKGROUND: Several studies have shown that patients with diabetes mellitus (DM) exhibit an impaired response to clopidogrel. This may contribute to their increased risk of recurrent atherothrombotic events, despite the use of dual-antiplatelet therapy. The mechanisms for impaired clopidogrel response in DM patients have not been fully elucidated. OBJECTIVES: The aim of this study was to explore the mechanisms for impaired clopidogrel-mediated platelet inhibition in patients with DM using a comprehensive methodological approach embracing both pharmacokinetic (PK) and pharmacodynamic (PD) assessments as well as ex vivo and in vitro investigations. METHODS: Patients (DM, n = 30; non-DM, n = 30) with stable coronary artery disease taking aspirin 81 mg/day and P2Y12 antagonist naive were enrolled. Blood was collected before and at various times (0.5, 1, 2, 4, 6, and 24 h) after a 600-mg loading dose of clopidogrel. PD assessments included vasodilator-stimulated phosphoprotein, light transmission aggregometry, and VerifyNow P2Y12 ex vivo, before and after dosing and following in vitro incubation with escalating concentrations (1, 3, and 10 μM) of clopidogrel's active metabolite (Clop-AM). Exposure to Clop-AM was also determined. RESULTS: PD assessments consistently showed that during the overall 24-h study time course, residual platelet reactivity was higher in DM patients compared with non-DM patients. In vitro incubation with Clop-AM revealed altered functional status of the P2Y12 signaling pathway in DM platelets as measured by vasodilator-stimulated phosphoprotein, but not with other PD assays. Clop-AM exposure was ∼40% lower in DM patients than in non-DM patients. CONCLUSIONS: The present study suggests that among DM patients, impaired P2Y12 inhibition mediated by clopidogrel is largely attributable to attenuation of clopidogrel's PK profile. This is characterized by lower plasma levels of Clop-AM over the sampling time course in DM patients compared with non-DM patients and only modestly attributed to altered functional status of the P2Y12 signaling pathway.
BACKGROUND: Several studies have shown that patients with diabetes mellitus (DM) exhibit an impaired response to clopidogrel. This may contribute to their increased risk of recurrent atherothrombotic events, despite the use of dual-antiplatelet therapy. The mechanisms for impaired clopidogrel response in DMpatients have not been fully elucidated. OBJECTIVES: The aim of this study was to explore the mechanisms for impaired clopidogrel-mediated platelet inhibition in patients with DM using a comprehensive methodological approach embracing both pharmacokinetic (PK) and pharmacodynamic (PD) assessments as well as ex vivo and in vitro investigations. METHODS:Patients (DM, n = 30; non-DM, n = 30) with stable coronary artery disease taking aspirin 81 mg/day and P2Y12 antagonist naive were enrolled. Blood was collected before and at various times (0.5, 1, 2, 4, 6, and 24 h) after a 600-mg loading dose of clopidogrel. PD assessments included vasodilator-stimulated phosphoprotein, light transmission aggregometry, and VerifyNow P2Y12 ex vivo, before and after dosing and following in vitro incubation with escalating concentrations (1, 3, and 10 μM) of clopidogrel's active metabolite (Clop-AM). Exposure to Clop-AM was also determined. RESULTS:PD assessments consistently showed that during the overall 24-h study time course, residual platelet reactivity was higher in DMpatients compared with non-DMpatients. In vitro incubation with Clop-AM revealed altered functional status of the P2Y12 signaling pathway in DM platelets as measured by vasodilator-stimulated phosphoprotein, but not with other PD assays. Clop-AM exposure was ∼40% lower in DMpatients than in non-DMpatients. CONCLUSIONS: The present study suggests that among DMpatients, impaired P2Y12 inhibition mediated by clopidogrel is largely attributable to attenuation of clopidogrel's PK profile. This is characterized by lower plasma levels of Clop-AM over the sampling time course in DMpatients compared with non-DMpatients and only modestly attributed to altered functional status of the P2Y12 signaling pathway.
Authors: Anna Toso; Stefano De Servi; Mario Leoncini; Dominick J Angiolillo; Paolo Calabrò; Federico Piscione; Marco Cattaneo; Diego Maffeo; Antonio Bartorelli; Cataldo Palmieri; Marco De Carlo; Davide Capodanno; Philippe Genereux; Francesco Bellandi; Chiara Barozzi; Luciana Tomasi; Diego Della Riva; Tullio Palmerini Journal: J Thromb Thrombolysis Date: 2017-10 Impact factor: 2.300
Authors: Thomas A Mavrakanas; Yiannis S Chatzizisis; Karim Gariani; Dean J Kereiakes; Giuseppe Gargiulo; Gérard Helft; Martine Gilard; Fausto Feres; Ricardo A Costa; Marie-Claude Morice; Jean-Louis Georges; Marco Valgimigli; Deepak L Bhatt; Laura Mauri; David M Charytan Journal: Clin J Am Soc Nephrol Date: 2019-04-22 Impact factor: 8.237
Authors: Dagmar F Hernandez-Suarez; Stuart A Scott; Matthew I Tomey; Kyle Melin; Angel Lopez-Candales; Charlotte E Buckley; Jorge Duconge Journal: Ther Adv Cardiovasc Dis Date: 2017-07-04