BACKGROUND Dual anti-platelet therapy with aspirin and a thienopyridine (DAT) is used to prevent stent thrombosis after percutaneous coronary intervention (PCI). Low response to clopidogrel therapy (LR) occurs, but laboratory tests have a controversial role in the identification of this condition. METHODS We studied LR in patients with stable angina undergoing elective PCI, all on DAT for at ...

High on-treatment platelet reactivity (HTPR) despite clopidogrel therapy is associated with adverse cardiac events after acute myocardial infarction (AMI). Most studies to date have assessed clopidogrel response at a single time point before or after percutaneous coronary intervention (PCI). It is unclear, however, whether the HTPR phenotype is stable over time. Therefore, we aimed to examine r...

OBJECTIVES This study sought to investigate clinical utility of on-site platelet function test and C-reactive protein (CRP) in patients undergoing percutaneous coronary intervention (PCI). BACKGROUND Data on long-term prognostic value of high on-treatment platelet reactivity (HTPR) on clopidogrel after PCI are limited. As a distinct biological pathway, CRP has been suggested to be associated ...

BACKGROUND The clinical efficacy of clopidogrel is hampered by a large interindividual variability in platelet inhibition. Polymorphisms in the P2RY12 receptor gene have been suggested to contribute to this variability, but previous studies included a relatively small number of patients and incompletely covered the common variation in the P2RY12 gene. The aim of this study was to comprehensivel...

BACKGROUND AND OBJECTIVES The aim of this study was to confirm the predictive cut-off values for P2Y12 reaction units (PRU) and aspirin reaction units (ARU) and to evaluate the clinical impact of VerifyNow® assays. SUBJECTS AND METHODS From November 2007 to October 2009, 186 eligible patients were prospectively recruited. Post-treatment platelet reactivity was measured by VerifyNow® assays wi...

Whilst poor response to clopidogrel is associated with adverse outcomes uncertainty exists as to how (a) response should be assessed and (b) poor responders managed. We utilised VerifyNow P2Y12 and short Thrombelastography (TEG) to assess 900 mg doses in (i) initial poor responders to 600 mg and (ii) in a randomised comparison with 600 mg. Blood was taken before and six hours post clopidogrel i...

In Reply: Drs. Slater and Lerner have reemphasized a critical point in our published case scenario1: Standard coagulation tests are inadequate in assessing adequacy of platelet function for epidural catheterization. Therefore, we recommended in our algorithm presented in figure 4 of our original report1 to use whole blood multiple electrode impedance aggregometry (Multiplate®; Roche Diagnostics...

BACKGROUND Previous studies have suggested that women do not accrue equal therapeutic benefit from antiplatelet medication as compared with men. The physiological mechanism and clinical implications behind this gender disparity have yet to be established. METHODS On-treatment platelet reactivity was determined in 717 men and 234 women on dual antiplatelet therapy, undergoing elective coronary...

BACKGROUND Type 2 diabetes (T2DM) patients are at increased risk of cardiovascular events despite long-term acetylsalicylic acid (ASA) therapy. This study was performed to establish the prevalence of high platelet reactivity (HPR) on ASA in T2DM and to identify its predictors. METHODS The study included 185 T2DM on chronic ASA therapy and to assess platelet reactivity during long-term ASA the...