The association between clopidogrel and 2-oxo-clopidogrel plasma levels and the long-term clinical outcome after acute myocardial infarction
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BACKGROUND AND OBJECTIVES: A significant number of ischemic events occur after acute myocardial infarction (MI), even when adhering to dual antiplatelet therapy including aspirin and clopidogrel. The aim of our study was to investigate the association between the concentration of the prodrug clopidogrel and its intermediary metabolite 2-oxo-clopidogrel plasma as well as demographic and clinical factors, and the long-term clinical outcome in patients with their first acute MI, ST-elevation myocardial infarction (STEMI) or non-ST-elevation myocardial infarction NSTEMI, treated with percutaneous coronary intervention (PCI). MATERIALS AND METHODS: This study included 172 consecutive patients with their first acute MI, 88 STEMI, and 84 NSTEMI, treated with PCI. On the third day of hospitalization, blood samples were collected from each patient to measure the concentration of clopidogrel and its metabolite 2-oxo-clopidogrel using the UHPLC-DAD-MS method. The following clinical outcomes were registered during the 28-month follow-up: mortality from cardiovascular causes, nonfatal MI, nonfatal stroke, and hospitalization for urgent myocardial revascularization or heart failure. RESULTS: Lower dose-adjusted clopidogrel concentrations (p < 0.05) were measured in NSTEMI patients with a composite of the hard clinical endpoint events of cardiovascular mortality, non-fatal MI, or a nonfatal stroke. During the follow-up, there was a 3.4 times higher risk of hard clinical endpoint events (p < 0.05) for each unit decrement of the dose-adjusted clopidogrel plasma concentration. Lower dose-adjusted concentrations of clopidogrel in these patients were associated with lower left ventricular ejection fraction (p < 0.001), and fentanyl (p < 0.001) and pantoprazole administration (p < 0.01) during the acute phase of MI. CONCLUSION: In patients with acute MI treated with PCI, lower dose-adjusted clopidogrel and dose-adjusted 2-oxo-clopidogrel plasma concentrations were associated with an increased risk of ischemic events.
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P-Glycoprotein Polymorphism C3435T Is Associated with Dose-Adjusted Clopidogrel and 2-Oxo-Clopidogrel Concentration.

BACKGROUND/AIMS: One of the most common polymorphisms of ABCB1 gene, a synonymous mutation C3435T (rs1045642), is associated with increased in vivo activity. The main goal of this study was to determine the association of C3435T polymorphism with clopidogrel and 2-oxo-clopidogrel concentrations in plasma. METHODS: The patients were recruited upon acute myocardial infarction diagnosis. They were all tested for ABCB1 C3435T polymorphism. In plasma, drawn 1 h after the drug administration, concentrations of clopidogrel and 2-oxo-clopidogrel were measured using UHPLC-DAD-MS analysis. RESULTS: Due to differences in the maintenance doses, we have calculated the dose-adjusted concentrations of clopidogrel (0.2 ng/ml/mg (0.1-0.4)) and 2-oxo-clopidogrel (2.1 ng/ml/mg (0.5-4.6)). Patients carrying at least one C allele achieved significantly higher serum concentration of clopidogrel (p < 0.001), as well as dose-adjusted clopidogrel (p < 0.001) and 2-oxo-clopidogrel concentrations (p < 0.05). CONCLUSION: The ABCB1 3435CC genotype is associated with increased clopidogrel and 2-oxo-clopidogrel dose-adjusted concentrations. Therefore, the ABCB1 C3435T genotyping should be one of the parameters taken into account when deciding about the dosing regimen of clopidogrel.

Antioxidant and antimicrobial potentials of Serbian red wines produced from international Vitis vinifera grape varieties.

BACKGROUND: Antioxidant and antimicrobial potentials of Serbian red wines produced from different international Vitis vinifera grape varieties and their correlation with contents of phenolic compounds were studied by spectrophotometric and chromatographic methods. The antioxidant activity of red wines was estimated through their ability to scavenge 2,2'-diphenyl-1-picrylhydrazyl free radical (DPPH(•) ). The red wines, gallic acid, (+)-catechin and quercetin were screened in vitro for antimicrobial activity against Gram-positive and Gram-negative strains using microdilution and disc diffusion techniques. RESULTS: Excellent correlations between the contents of quercetin-3-glucoside (R(2) = 0.9463) and quercetin (R(2) = 0.9337) and DPPH(•) -scavenging ability of the red wines were found. Serbian red wines exhibited significant activity against Staphylococcus aureus, Listeria inocua, Micrococcus flavus, Sarcina lutea, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis and Shigella sonnei strains, which was in correlation with their phenolic composition and antioxidant activity. The compounds gallic acid, quercetin and (+)-catechin showed high activity against B. subtilis, S. aureus, S. lutea and M. flavus Gram-positive and S. enteritidis and P. aeruginosa Gram-negative strains. CONCLUSION: The results show that quercetin-3-glucoside and quercetin concentrations can be used as markers for the determination of antioxidant and antimicrobial potentials of red wines.

The association of clopidogrel and 2-oxo-clopidogrel plasma levels and the 40 months clinical outcome after primary PCI.

Background A significant number of ischemic events occur even when adhering to dual antiplatelet therapy including aspirin and clopidogrel. Objectives The aim of our study was to determine predictors of long-term patient clinical outcome, among variables such as prodrug clopidogrel and intermediary metabolite 2-oxoclopidogrel concentrations, as well as patients' clinical characteristics. Setting Department for the Treatment of Acute Coronary Syndrome in tertiary teaching hospital, Serbia. Methods This study enrolled 88 consecutive patients with first STEMI, treated with primary PCI, within 6 h of the chest pain onset and followed them 40 months. On the third day of hospitalization, blood samples were collected from each patient to measure clopidogrel and its metabolite 2-oxo-clopidogrel concentration by UHPLC-DAD-MS method. Main outcome measure Mortality from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke or hospitalization for urgent myocardial revascularization or heart failure. Results The composite clinical outcome of cardiovascular mortality, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for urgent myocardial revascularization or heart failure, was registered in 31 patients (35.2%) during the 40-month follow-up. Lower clopidogrel (p < 0.05) and dose-adjusted clopidogrel concentrations (p < 0.05) were associated with the higher incidence of composite outcome events. Their low plasma concentrations may be predicted by fentanyl administration (p < 0.001) and creatinine clearance (p < 0.01). The decrease in dose-adjusted clopidogrel unit for each ng/ml/mg increases the risk 21.7 times (p < 0.05). Conclusion Clopidogrel dose-adjusted plasma concentration in STEMI patients, as well as multivessel coronary artery disease, showed significance in predicting an unfavorable composite clinical outcome after 40-month follow-up.