AIMS Patients with diabetes mellitus (DM) have increased platelet reactivity and reduced platelet response to clopidogrel compared with patients without DM. Prasugrel, a more potent antiplatelet agent, is associated with greater reductions in ischaemic events compared with clopidogrel, particularly in patients with DM. The aim of this study was to perform serial pharmacodynamic assessments of p...

OBJECTIVES This study sought to assess the presence of a dose-response effect of cigarette smoking and its impact on high on-treatment platelet reactivity (HPR) in patients with diabetes mellitus treated with clopidogrel. BACKGROUND Cigarette smoking is an inducer of cytochrome P450 1A2, a hepatic enzyme involved in clopidogrel metabolism. If cigarette smoking is associated with a dose-respon...

OBJECTIVES The authors performed this analysis to examine whether the enhanced clopidogrel responsiveness in current smokers is maintained after adjusting the influence of hemoglobin on VerifyNow P2Y12 reaction unit (PRU). BACKGROUND PRU is consistently reported to be lower in current smokers. However, PRU has a significant inverse relationship with hemoglobin level, and smokers have higher h...

While up to 70% of patients have resistance clopidogrel (Plavix) in the coronary literature, testing is not routinely performed despite its common use as an antiplatelet for prevention stent thrombosis transcarotid arterial revascularization (TCAR) procedures. The extent which exists undergoing TCAR has been well-described. We sought compare modalities and determine prevalence effect on outcome...

BACKGROUND Aspirin is a cornerstone in management of coronary artery disease (CAD). However, considerable variability in the antiplatelet effect of aspirin has been reported. AIM To investigate independent determinants of reduced antiplatelet effect of aspirin in stable CAD patients. METHODS We performed a cross-sectional study including 900 stable, high-risk CAD patients. Among these, 795 ...

Background—In the Gauging Responsiveness With A VerifyNow P2Y12 Assay: Impact on Thrombosis and Safety (GRAVITAS) trial, 6 months of high-dose clopidogrel did not reduce cardiovascular events compared with standard-dose clopidogrel in patients with high on-treatment platelet reactivity (OTR) after percutaneous coronary intervention, defined as OTR 230 P2Y12 reaction units according to the Verif...

BACKGROUND Hyperglycaemia may attenuate the antiplatelet effect of aspirin and thereby increase the risk of cardiovascular events. We investigated the influence of increased haemoglobin A1c (HbA1c) levels on platelet aggregation and turnover in a large cohort of patients with coronary artery disease (CAD) with type 2 diabetes, prediabetes or no diabetes. METHODS In this observational study, w...

AIMS The metabolic pathways leading to the formation of prasugrel and clopidogrel active metabolites differ. We hypothesized that decreased CYP2C19 activity affects the pharmacokinetic and pharmacodynamic response to clopidogrel but not prasugrel. METHODS AND RESULTS Ninety-eight patients with coronary artery disease (CAD) taking either clopidogrel 600 mg loading dose (LD)/75 mg maintenance d...

BACKGROUND The influence of cytochrome P450 (CYP) 2C19 genotype on platelet function in patients treated with ticagrelor versus clopidogrel is unknown. METHODS AND RESULTS CYP2C19 (*1, *2, *3, *4, *5, *6, *7, *8, *17) genotyping was performed in patients with coronary artery disease treated with ticagrelor (180-mg load, 90 mg BID) (n=92) or clopidogrel (600-mg load, 75 mg/d) (n=82). All patie...