Impact of VKORC1, CYP2C9, and CYP4F2 Polymorphisms on Optimal Warfarin Dose: Does Ethnicity Matters?

Background: Conventional anticoagulation with warfarin remains the cornerstone strategy for numerous preventive strategies. It is established that Asian patients require lower warfarin doses than Caucasians potentially attributing to the genetic polymorphism (GP) differences.

Areas Of Uncertainty: The impact of GP on optimal warfarin dose (OWD) in Koreans is unclear when compared with other ethnicities.

Pharmacodynamic study of prasugrel or clopidogrel in non-ST-elevation acute coronary syndrome with CYP2C19 genetic variants undergoing percutaneous coronary intervention (PRAISE-GENE trial).

Background: The CYP2C19*2 or *3 loss-of-function (LOF) allele is associated with high platelet reactivity (HPR) on clopidogrel treatment. East Asians may benefit from a lower dose of prasugrel due to their more potent platelet inhibitory response. The impact of LOF alleles on the pharmacodynamic response to half-dose prasugrel in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) undergoing percutaneous coronary intervention (PCI) is unknown.

Platelet microRNA for predicting acute myocardial infarction.

Acute myocardial infarction (AMI) is one of the leading causes of morbidity and mortality worldwide, while early diagnosis still represents an upmost priority. While platelet activation is critical for AMI pathogenesis, the role of platelet microRNAs (pmiRNAs) as biomarkers for AMI is unclear. Furthermore, correlations between the levels of pmiRNAs and indices of platelet activity are also unknown.

Impact of renal impairment on platelet reactivity and clinical outcomes during chronic dual antiplatelet therapy following coronary stenting.

Aims: Clinical utilization of dual antiplatelet therapy (DAPT) in patients with renal impairment (RI) following percutaneous coronary interventions (PCI) represents an urgent, unmet need choosing optimal agents, duration of treatment, and potential dose/regimen adjustment. The lack of any large randomized trials specifically in RI patients, and the absence of the uniformed clinical data reporting policy, clouds the reality. Moreover, triaging RI patients is problematic due to ongoing kidney deterioration, and the fact that RI patients are prone to both vascular occlusions and bleeding.

Thienopyridine reloading in clopidogrel-loaded patients undergoing percutaneous coronary interventions: The PRAISE study.

Objective: The impact of thienopyridine reloading on clinical outcomes, and residual high platelet reactivity (HPR) is unclear. We sought to compare the HRP-related effect of prasugrel and clopidogrel reloading in the already clopidogrel-loaded patients undergoing percutaneous coronary intervention (PCI).

Materials And Methods: In this prospective, two-center, randomized, open-label study, patients with HPR who had undergone PCI after a clopidogrel (300-600mg) loading dose (LD) were enrolled.

Comparison of Three Tests to Distinguish Platelet Reactivity in Patients with Renal Impairment during Dual Antiplatelet Therapy.

Background: Clopidogrel and aspirin combination remains a cornerstone for modern dual antiplatelet therapy (DAPT) following coronary stenting. Although monitoring is not currently recommended, certain high-risk cohorts may benefit from tailoring antiplatelet options to reduce thrombotic or/and hemorrhagic risks. Patients with diminished estimated glomerular filtration rate (eGFR) are prone to both vascular occlusions and bleeding events in whom monitoring may be especially advantageous.

Angio-Vasculogenic Properties of Endothelial-Induced Mesenchymal Stem Cells Derived From Human Adipose Tissue.

Background: Although stem cells have been regarded as a promising therapeutic option, the marginal therapeutic effects of stem cells are limitations that must be overcome for the development of effective cell therapy. This study sought to identify the angio-vasculogenic properties of endothelial differentiated mesenchymal stem cells (MSCs) and to determine whether these cells are effective for vascular repair.

Methods and results: Adipose MSCs were cultured for 10 days under endothelial cell (EC) culture conditions.

Concomitant nitrates enhance clopidogrel response during dual anti-platelet therapy.

Background: Despite advances in modern anti-platelet strategies, clopidogrel still remains the cornerstone of dual anti-platelet therapy (DAPT) in patients undergoing percutaneous coronary interventions (PCI). There is some inconclusive evidence that response after clopidogrel may be impacted by concomitant medications, potentially affecting clinical outcomes. Sustained released nitrates (SRN) are commonly used together with clopidogrel in post-PCI setting for mild vasodilatation and nitric oxide-induced platelet inhibition.

Correlation between the CYP2C19 phenotype status and the results of three different platelet function tests in cardiovascular disease patients receiving antiplatelet therapy: an emphasis on newly introduced platelet function analyzer-200 P2Y test.

Background: An association has been reported between CYP2C19 polymorphism and the altered antiplatelet activity of clopidogrel. We investigated this association using the newly introduced platelet function analyzer (PFA)-200 (INNOVANCE PFA-200 System; Siemens Healthcare, Germany) P2Y test.

Methods: Polymorphisms of CYP2C19*2, *3, *17 and the degree of inhibition of platelet function were determined in 83 patients.

Comparison of Prasugrel and Ticagrelor Antiplatelet Effects in Korean Patients Presenting With ST-Segment Elevation Myocardial Infarction.

Background: There is insufficient data on the efficacy of prasugrel and ticagrelor in Korean patients with ST-segment elevation myocardial infarction (STEMI).

Methods And Results: I n the current double-blind, prospective pilot study, 39 patients with STEMI undergoing primary percutaneous coronary intervention were randomized to receive prasugrel 60 mg loading dose (LD) followed by 10 mg daily maintenance dose (n=19), or ticagrelor 180 mg LD followed by 90 mg twice daily maintenance dose (n=20). We assessed platelet reactivity with the VerifyNow and Vasodilator-Stimulated Phosphoprotein (VASP) P2Y12 assays.

Falsely high B-type natriuretic peptide concentration in patients without heart failure attributed to AxSYM assay: case series of eight subjects.

We report a case series of eight subjects complaining of non-specific chest pain without heart failure, but with apparent high concentrations of plasma B-type natriuretic peptide (BNP). No positive clinical characteristics were identified in physical examinations, cardiac imaging, laboratory findings, or pulmonary function tests. However, we observed unusually high BNP values when analysing blood samples of the patients using the AxSYM assay, and this was not supported by readings from Triage® or ADVIA Centaur® assays on the same samples, which showed BNP within the normal range.

Lower loading dose of prasugrel compared with conventional loading doses of clopidogrel and prasugrel in korean patients undergoing elective coronary angiography: a randomized controlled study evaluating pharmacodynamic efficacy.

Background And Objectives: Although prasugrel allows for rapid and potent platelet inhibition, the efficacy and safety of lower doses of prasugrel for patients of East Asian ethnicity has not yet been investigated. We compared the effect of a lower loading dose (LD) of prasugrel with conventional LDs of clopidogrel and prasugrel in Korean patients.

Subjects And Methods: Forty-three Korean patients undergoing coronary angiography were enrolled in the study.

Comparison of pharmacodynamics between low dose ticagrelor and clopidogrel after loading and maintenance doses in healthy Korean subjects.

The novel antiplatelet agent ticagrelor has been demonstrated to exert a faster and more powerful inhibition of platelet aggregation in comparison to clopidogrel in coronary artery disease patients. However, a ticagrelor dose of 90 mg twice daily might not be suitable for patients of East Asian ethnicity, and has not been fully investigated. The aim of this study was to assess the effects of low loading doses (LD, 90 mg) and maintenance doses (MD, 90 mg daily) of ticagrelor in comparison to clopidogrel (600 mg LD, 75 mg daily MD) in healthy Korean volunteers.