Paraoxonase-1 is a major determinant of clopidogrel efficacy

Effect of loss-of-function CYP2C19 variants on clinical outcomes in coronary artery disease patients treated with clopidogrel: A systematic meta-analysis approach

For many years, clopidogrel has been a commonly utilised antiplatelet drug in the management of coronary artery disease (CAD). It's thought that the CYP2C19 loss of function (LoF) polymorphism causes clopidogrel's poor metabolism, which eventually leads to resistance. Previous research produced extremely divergent and inconsistent results, making it impossible to draw definitive conclusions. Therefore, current, investigation was carried out to obtain definitive evidence from an updated meta-analysis on the connection between CYP2C19 LoF polymorphism and coronary artery event in patients treated with clopidogrel. 52,542 individuals with coronary artery disease who were receiving clopidogrel treatment were included in 87 carefully chosen trials from reliable databases that we used for our meta-analysis. According to our data, those who carry one or more CYP2C19 LoF alleles worldwide are much more likely to experience composite events and coronary artery events than people who do not carry these alleles, especially in Asian populations. Our meta-analysis observed that the global population, particularly Asians receiving clopidogrel treatment, is at risk of recurrent coronary artery events and composite events if they carry the CYP2C19 LoF alleles. Additional research is essential on alternative antiplatelet therapies for individuals who exhibit poor or intermediate metabolic activity. OBJECTIVES: 1.To systematically analyze the current evidence regarding the association of CYP2C19 variants with coronary artery disease (CAD). 2.To conduct a meta-analysis to investigate the association between loss of function (LoF) CYP2C19 modifications and CAD.

Paraoxonase-1 as a Cardiovascular Biomarker in Caribbean Hispanic Patients Treated with Clopidogrel: Abundance and Functionality

Clopidogrel, a prescription drug to reduce ischemic events in cardiovascular patients, has been extensively studied in mostly European individuals but not among Caribbean Hispanics. This study evaluated the low abundance and reduced activity of paraoxonase-1 (PON1) in clopidogrel-resistant patients as a predictive risk biomarker of poor responders and disease severity in this population. Thirty-six patients on clopidogrel (cases divided into poor and normal responders) were enrolled, along with 11 cardiovascular patients with no clopidogrel indications (positive control) and 13 healthy volunteers (negative control). Residual on-treatment platelet reactivity unit (PRU), PON1 abundance by Western blotting, and PON1 activity by enzymatic assays were measured. PON1 genotyping and computational haplotype phasing were performed on 512 DNA specimens for two genetic loci (rs662 and rs854560). No statistical differences in mean relative PON1 abundance were found among the groups (p > 0.05). However, a significantly lower enzymatic activity was found in poor responders (10.57 ± 6.79 µU/mL) when compared to controls (22.66 ± 8.30 µU/mL and 22.21 ± 9.66 µU/mL; p = 0.004). PON1 activity among carriers of the most prevalent PON1 haplotype (AA|AA) was significantly lower than in wild types (7.90 µU/mL vs. 22.03 µU/mL; p = 0.005). Our findings suggested that PON1 is a potential biomarker of cardiovascular disease severity in Caribbean Hispanics.

Association of genetic variations of 3'-UTR in clopidogrel pharmacokinetic-relevant genes with clopidogrel response in Han Chinese patients with coronary artery disease

Dual antiplatelet therapy with aspirin and clopidogrel has reduced ischemic vascular events significantly. Genetic influence, especially those in clopidogrel pharmacokinetic-relevant genes partially accounts for interindividual pharmacodynamic variability of clopidogrel. However, most studies have concentrated on the genetic variations in introns, exons, or promoters of the candidate genes, and the association between genetic variations in 3'-UTR in clopidogrel pharmacokinetic-relevant genes and clopidogrel response is unknown. In our study, ten different algorithms were applied to pick potential miRNAs targeting the clopidogrel pharmacokinetic-relevant genes. Furthermore, the correlation between miRNA expression profiles and mRNA expression of corresponding clopidogrel pharmacokinetic-relevant genes was analyzed. Through comprehensive analysis, including bioinformatics prediction and correlation analysis of miRNA and mRNA expression profiles, miR-218-5p and miR-506-5p were supposed to regulate the expression of PON1 via binding with its 3'-UTR. Moreover, PON1 rs854551 and rs854552 were located in miRNA recognizing sequences and may serve as potential miRSNPs possibly affecting PON1 expression. The rs854552 polymorphism was genotyped and platelet reactivity index (PRI) indicative of clopidogrel response was measured in 341 Chinese coronary artery disease (CAD) patients 24 h after administration of 300 mg clopidogrel. Our results showed that PON1 rs854552 had a significant influence on PRI in CAD patients, especially in patients with CYP2C19 extensive metabolic phenotype. In conclusion, PON1 rs854552 polymorphisms may affect clopidogrel response. Bioinformatics prediction followed by functional validation could aid in decoding the contribution of unexplained variations in the 3'-UTR in drug-metabolizing enzymes on clopidogrel response.

Association between paraoxonase 1 -108C/T polymorphism and coronary heart disease: an updated meta-analysis

Background

At present, no consensus is reached among articles that investigate the relationship of paraoxonase 1(PON1) -108C/T polymorphism with susceptibility of coronary heart disease (CHD) so far. In this regard, the present meta-analysis was conducted to comprehensively review existing articles related to the relationship of PON1 -108C/T polymorphism with CHD susceptibility. It was preregistered in the International Platform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY)-INPLASY202430117.

Methods

Articles that explored the relationship between PON1 -108C/T polymorphism and CHD incidence were searched from electronic databases according to our preset study selection criteria. Thereafter, we adopted stata 12.0 software to analyze our screened studies. At the same time, odds ratios (ORs) and related 95% confidence intervals (95% CIs) were determined for evaluating association strength.

Results

At last, this meta-analysis selected altogether 13 case-control studies that involved 2,979 cases and 2,887 control subjects. We found that the PON1 -108C/T polymorphism displayed marked relationship with CHD susceptibility (T vs. C: OR = 1.24, 95% CI 1.07-1.45; CT vs. CC: OR = 1.33, 95% CI 1.17-1.52; TT vs. CC: OR = 1.51, 95% CI 1.09-2.09; Recessive model: OR = 1.16, 95% CI 0.93-1.45; Dominant model: OR = 1.45, 95% CI 1.16-1.81). Moreover, subgroup analysis showed that race and sample size had no impact on the results. Bioinformatics analysis showed that -108C>T polymorphism was relation to PON1 gene expression (https://gtexportal.org/home/).

Conclusions

The PON1 -108T allele is identified as the possible low-penetrant risk factor of CHD, as suggested by our present meta-analysis.Systematic Review Registration: https://inplasy.com/inplasy-2024-3-0117/, Identifier INPLASY202430117.

Clinical efficacy of clopidogrel and ticagrelor in patients undergoing off-pump coronary artery bypass grafting: a retrospective cohort study

BACKGROUND

Ticagrelor is reportedly more effective than clopidogrel in preventing atherothrombotic events in patients with percutaneous coronary intervention. However, the optimal antiplatelet therapy strategy after off-pump coronary artery bypass grafting (OPCABG) is yet to be established.

MATERIALS AND METHODS

This study was performed using the prospectively-maintained database at our institution. Patients who underwent OPCABG were divided into the clopidogrel and the ticagrelor groups. Propensity score matching analysis was performed between the two groups. The clinical outcome was the occurrence of major adverse cardiovascular event (MACE), defined as a composite of vascular death, myocardial infarction, or stroke 1-year after surgery.

RESULTS

In total, 545 patients completed the entire follow-up assessment. After propensity score matching, 232 patients each were included in the clopidogrel and ticagrelor groups. The primary outcome occurred in 7.8 and 4.3% of patients in the clopidogrel and ticagrelor groups, respectively ( P =0.113). CYP2C19 variants (*2, *3, and *17) did not impact the clinical outcomes, regardless of the use of clopidogrel or ticagrelor. The rates of MACE were significantly lower in patients carrying the ABCB1 C3435T CT/TT genotypes in the ticagrelor group than in those carrying the ABCB1 C3435T CC genotype in the clopidogrel group (1.4 vs. 9.1%, adjusted P =0.030), as well as those carrying the ABCB1 C3435T CC genotype in the ticagrelor group (1.4 vs. 8.9%, adjusted P =0.036). The ABCB1 C3435T CC genotype was significantly associated with the incidence of 1-year MACE (HR=1.558, 95% CI: 1.109-2.188, P =0.011). Patients who experienced severe perioperative bleeding exhibited a significantly higher incidence of MACE than those who did not experience severe perioperative bleeding (14.0 vs. 4.9%, adjusted P =0.007).

CONCLUSION

There was no significant difference in the 1-year MACE between patients receiving clopidogrel and those receiving ticagrelor after OPCABG. Notably, The ABCB1 C3435T CC genotype was related to a higher risk of MACE.

Development and assessment of immediate-release tablets containing clopidogrel bisulphate & aspirin-strategy for optimizing the combination formulation

The main goal of the study was to improve the compliance and convenience of patients by designing and development of an immediate release (IR) fixed-dose combination (Clopidogrel bisulphate and Aspirin) tablets. The proposed combination product utilizes Clopidogrel to protect the moisture-sensitive aspirin component, enhancing its stability against atmospheric conditions. Response-surface approach (Design Expert vs. 13) was used to generate this IR tablet by calculating the right composition of independent variables such as Microcrystalline cellulose 102, pregelatinized starch and Hydroxypropyl cellulose. 32 factorial design was used to estimate the effects of these independent variables on the responses of dependent variables (disintegration & friability) and constructed a total of nine (9) formulations. Pre and Post formulation, quality control parameters were investigated as per pharmacopeia. A systematic approach was used for the optimization process and a prototype checkpoint batch (CPB) based on the better contrast of independent variables was prepared. In vitro analysis of formulations was carried out to estimate the responses. Friability was found in the range of 0.088-1.076%w/w, except F1 = 1.076 all are within limits (NMT 1.0%). Disintegration time was recorded 7.3 ± 1.20 as lower and 24.5 ± 1.63 min was the highest. The release of drugs from their dosage form was fast and rapid, for clopidogrel after 15min was 70.42-96.82% with SD ± 8.71 and aspirin was 69.88-91.49% in 15 min with SD ± 6.41, all the tablets were released more than 80% in 20 min. The stability outcomes of CPB tablets after 15 days of stress study (60 ± 2°C and 75 ± 5%) indicated good compatibility and stability of APIs with excipients. It was concluded that the direct compression method can be preferred to prepare a combination product with cost-effectiveness. It was also concluded that the proposed methodology could increase Aspirin's stability and allow for an aqueous coating system to finish the product with a film coating. By using Design Expert software, the best composition of the formulation can be selected and optimized in a short period of time with minimum trial and errors. The results also demonstrated that the use of a fixed-dose combination tablet instead of the individual is expected to be more convenient to patients and thus improves patient compliance and decreases the occurrence of adverse effects and side effects.

Advances and Perspectives in methods for identifying high platelet reactivity

Antiplatelet therapy is the foundational treatment for the prevention and treatment of coronary and cerebrovascular ischemic events in patients with coronary heart disease, ischemic stroke, and transient ischemic attack (TIA). However, with more and more studies reporting an increased risk of thrombosis in some patients due to poor response to therapeutic agents, the selection of appropriate P2Y12 inhibitors has become a major challenge that needs to be addressed urgently. Currently, commonly used oral P2Y12 inhibitors include clopidogrel, ticagrelor, and prasugrel. Assessing patients' risk factors before the development of treatment regimens by effectively predicting the risk of high platelet reactivity with specific P2Y12 inhibitors in advance to avert the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) is the key point to the problem. Up to now, methods available for predicting platelet reactivity include genetic testing, platelet function testing, and risk scores. This review provides a summarization of the existent available identification methods and analyzes the advantages and drawbacks of different methods in specific clinical settings, intending to guide the rational clinical application of P2Y12 receptor inhibitors.

5-(3',4'-Dihydroxyphenyl)-γ-Valerolactone Is a Substrate for Human Paraoxonase: A Novel Pathway in Flavan-3-ol Metabolism

SCOPE

Dietary flavan-3-ols are known to mediate cardiovascular benefits. Currently, it is assumed that the levels of flavan-3-ol catabolites detected in humans, 5-(3',4'-dihydroxyphenyl)-γ-valerolactone (γVL) and 5-(3',4'-dihydroxyphenyl)-γ-valeric acid (γVA), and their corresponding phase II metabolites, are determined exclusively by the action of the gut microbiome. However, a family of human proteins, paraoxonase (PON), can theoretically hydrolyze γVL metabolites into the corresponding γVAs. This study aims to determine if PON is involved in γVL and γVA metabolism in humans.

METHODS AND RESULTS

A rapid conversion of γVL into γVA is detected in serum ex vivo (half-life = 9.8 ± 0.3 min) that is catalyzed by PON1 and PON3 isoforms. Phase II metabolites of γVL are also reacted with PON in serum. Following an intake of flavan-3-ol in healthy males (n = 13), the profile of γVA metabolites detected is consistent with that predicted from the reactivity of γVL metabolites with PON in serum. Furthermore, common PON polymorphisms are evaluated to assess the use of γVL metabolites as biomarkers of flavan-3-ol intake.

CONCLUSION

PONs are involved in flavan-3-ol metabolic pathway in humans. PON polymorphisms have a minor contribution to inter-individual differences in the levels of γVL metabolites, without affecting their use as a nutritional biomarker.

Association between Q192R PON1 genetic polymorphism and major adverse cardiovascular events in patients treated with clopidogrel: an updated meta-analysis

BACKGROUND

Clopidogrel's responsiveness may be affected by the paraoxonase-1 (PON1) enzyme encoded by the Q192R PON1 genetic variant. We aimed to determine the aggregated risk of MACEs associated with carrying Q192R PON1 genetic variant in patients taking clopidogrel.

RESEARCH DESIGN AND METHODS

Different databases were searched systematically for eligible studies, and risk ratio (RR) was measured using RevMan software where P <0.05 was set statistically significant.

RESULTS

Nineteen studies were included consisting of 17,815 patients. It was found that patients carrying either homozygous or a combination of heterozygous and homozygous variants were not significantly associated with increased risk of MACEs compared to the non-carriers (QQ vs. RR: RR=0.99, 95% CI 0.69-1.42, P=0.96; QQ+QR vs RR; RR=1.05, 95% CI 0.82-1.35, P=0.70). The risk of MACEs was also not significantly different in other genetic model (QQ vs QR+RR) (RR=1.09, 95% CI 0.93-1.27, P=0.30). Further, bleeding events were not significantly different in different genetic models (QQ vs RR; RR=1.13, 95% CI 0.58-2.21, P=0.71; QQ+QR vs RR; RR=1.09, 95% CI 0.66-1.81, P=0.73; QQ vs QR+RR; RR=1.08, 95% CI 0.76-1.55, P=0.66).

CONCLUSIONS

The results suggest that the Q192R PON1 genetic polymorphism has no significant impact on the risk of MACEs or bleeding events in patients treated with clopidogrel.

Comprehensive analysis of the clinical significance, immune infiltration, and biological role of MARCH ligases in HCC

The membrane‐associated RING‐CH (MARCH) family, a member of the E3 ubiquitin ligases, has been confirmed by a growing number of studies to be associated with immune function and has been highlighted as a potential immunotherapy target. In our research, hepatocellular carcinoma (HCC) patients were divided into C1 and C2 MARCH ligase-related patterns by the non-negative matrix factorization (NMF) algorithm. Multiple analyses revealed that the MARCH ligase-related cluster was related to prognosis, clinicopathological characteristics, and the tumor immune microenvironment (TIME). Next, the signature (risk score) of the MARCH prognosis was constructed, including eight genes associated with the MARCH ligase (CYP2C9, G6PD, SLC1A5, SPP1, ANXA10, CDC20, PON1, and FTCD). The risk score showed accuracy and stability. We found that the correlations between risk score and TIME, tumor mutation burden (TMB), prognosis, and clinicopathological characteristics were significant. Additionally, the risk score also had important guiding significance for HCC treatment, including chemotherapy, immunotherapy, and transarterial chemoembolization (TACE).

Lower paraoxonase 1 paraoxonase activity is associated with a worse prognosis in patients with non-ST-segment elevation myocardial infarction in long-term follow-up

BACKGROUND

Acute coronary syndrome (ACS) is one of the main manifestations of coronary artery disease, with a higher prevalence and worst prognosis. Oxidative stress is important in atherosclerosis and ACS, and paraoxonase 1 (PON1) is directly related to reducing the effects of oxidative stress on lipoproteins. The present study evaluated the prognostic value of PON1 activity in patients with non-ST-segment elevation ACS [non-ST-segment elevation myocardial infarction (NSTEMI) and unstable angina (UA)], included in the ERICO study.

METHODS

PON1 paraoxonase activity was determined in serum samples from 485 patients collected on admission. The prognostic value in the follow-up of up to 5 years was evaluated according to cutoff points established by tertiles. Kaplan-Meier curves and Cox regression were used for the analysis of all-cause mortality and cardiovascular mortality.

RESULTS

The sample consisted mainly of elderly patients with a high frequency of cardiovascular risk factors. At follow-up of up to 5 years, there were 126 deaths from all causes (80 deaths from CVD). The lowest tertile of PON1 paraoxonase activity was associated with a higher risk of death in patients with NSTEMI, but not in patients with UA.

CONCLUSION

PON1 paraoxonase activity has potential prognostic value in patients with NSTEMI.

Clinical pharmacology of antiplatelet drugs

INTRODUCTION

Platelets play a key role in arterial thrombosis and antiplatelet therapy is pivotal in the treatment of cardiovascular disease. Current antiplatelet drugs target different pathways of platelet activation and show specific pharmacodynamic and pharmacokinetic characteristics, implicating clinically relevant drug-drug interactions.

AREAS COVERED

This article reviews the role of platelets in hemostasis and cardiovascular thrombosis, and discusses the key pharmacodynamics, drug-drug interactions and reversal strategies of clinically used antiplatelet drugs.

EXPERT OPINION

Antiplatelet therapies target distinct pathways of platelet activation: thromboxane A₂ synthesis, adenosine diphosphate-mediated signaling, integrin α_IIbβ₃ (GPIIb/IIIa), thrombin-mediated platelet activation via the PAR1 receptor and phosphodiesterases. Key clinical drug-drug interactions of antiplatelet agents involve acetylsalicylic acid - ibuprofen, clopidogrel - omeprazole, and morphine - oral P2Y₁₂ inhibitors, all of which lead to an attenuated antiplatelet effect. Platelet function and genetic testing and the use of scores (ARC-HBR, PRECISE-DAPT, ESC ischemic risk definition) may contribute to a more tailored antiplatelet therapy. High on-treatment platelet reactivity presents a key problem in the acute management of ST-elevation myocardial infarction (STEMI). A treatment strategy involving early initiation of an intravenous antiplatelet agent may be able to bridge the gap of insufficient platelet inhibition in high ischemic risk patients with STEMI.

Pleiotropic effects of clopidogrel

Clopidogrel is a widely prescribed prodrug with anti-thrombotic activity through irreversible inhibition of the P2Y₁₂ receptor on platelets. It is FDA-approved for the clinical management of thrombotic diseases like unstable angina, myocardial infarction, stroke, and during percutaneous coronary interventions. Hepatic clopidogrel metabolism generates several distinct metabolites. Only one of these metabolites is responsible for inhibiting the platelet P2Y₁₂ receptor. Importantly, various non-hemostatic effects of clopidogrel therapy have been described. These non-hemostatic effects are perhaps unsurprising, as P2Y₁₂ receptor expression has been reported in multiple tissues, including osteoblasts, leukocytes, as well as vascular endothelium and smooth muscle. While the "inactive" metabolites have been commonly thought to be biologically inert, recent findings have uncovered P2Y₁₂ receptor-independent effects of clopidogrel treatment that may be mediated by understudied metabolites. In this review, we summarize both the P2Y₁₂ receptor-mediated and non-P2Y₁₂ receptor-mediated effects of clopidogrel and its metabolites in various tissues.

Physiologically Based Pharmacokinetic (PBPK) Modeling of Clopidogrel and Its Four Relevant Metabolites for CYP2B6, CYP2C8, CYP2C19, and CYP3A4 Drug–Drug–Gene Interaction Predictions

The antiplatelet agent clopidogrel is listed by the FDA as a strong clinical index inhibitor of cytochrome P450 (CYP) 2C8 and weak clinical inhibitor of CYP2B6. Moreover, clopidogrel is a substrate of—among others—CYP2C19 and CYP3A4. This work presents the development of a whole-body physiologically based pharmacokinetic (PBPK) model of clopidogrel including the relevant metabolites, clopidogrel carboxylic acid, clopidogrel acyl glucuronide, 2-oxo-clopidogrel, and the active thiol metabolite, with subsequent application for drug–gene interaction (DGI) and drug–drug interaction (DDI) predictions. Model building was performed in PK-Sim^® using 66 plasma concentration-time profiles of clopidogrel and its metabolites. The comprehensive parent-metabolite model covers biotransformation via carboxylesterase (CES) 1, CES2, CYP2C19, CYP3A4, and uridine 5′-diphospho-glucuronosyltransferase 2B7. Moreover, CYP2C19 was incorporated for normal, intermediate, and poor metabolizer phenotypes. Good predictive performance of the model was demonstrated for the DGI involving CYP2C19, with 17/19 predicted DGI AUC_last and 19/19 predicted DGI C_max ratios within 2-fold of their observed values. Furthermore, DDIs involving bupropion, omeprazole, montelukast, pioglitazone, repaglinide, and rifampicin showed 13/13 predicted DDI AUC_last and 13/13 predicted DDI C_max ratios within 2-fold of their observed ratios. After publication, the model will be made publicly accessible in the Open Systems Pharmacology repository.

Bibliometric and Visual Analysis on Metabolomics in Coronary Artery Disease Research

Background

Metabolomics has immense research value in coronary artery disease and has drawn increasing attention over the past decades. Many articles have been published in this field, which may challenge researchers aiming to investigate all the available information. However, bibliometrics can provide deep insights into this research field.

Objective

We aimed to qualitatively and quantitatively study metabolomics and coronary artery disease research, visually analyse the development status, trends, research hotspots, and frontiers of this field, and provide a reference for research on coronary artery disease.

Methods

Articles were acquired from the Web of Science Core Collection. VOSviewer and CiteSpace software were used to analyse publication growth, country/region, institution, journal distribution, author, reference, and keywords, and detected the keywords with strong citation burstness to identify emerging topics.

Results

A total of 1121 references were obtained, and the annual number of publications increased over the past 16 years. Metabolomics research has shown a gradual upward trend in coronary artery disease. The United States of America and China ranked at the top in terms of percentage of articles. The institution with the highest number of research publications in this field was Harvard University, followed by the University of California System and Brigham Women's Hospital. The most frequently cited authors included Hazen SL, Tang WH, and Wang ZN. Ala-Korpela M was the most productive author, followed by Clish CB and Adamski J. The journal with the most publications in this field was Scientific Reports, followed by PLoS One and the Journal of Proteome Research. The keywords used at a high frequency were "risk," "biomarkers," "insulin resistance," and "atherosclerosis." Burst detection analysis of top keywords showed that "microbiota," "tryptophan," and "diabetes" are the current research frontiers in this field.

Conclusion

This study provides useful information for acquiring knowledge on metabolomics and coronary artery diseases. Metabolomics research has shown a gradual upward trend in coronary artery disease studies over the past 16 years. Research on tryptophan metabolism regulated by intestinal flora will become an emerging academic trend in this field, which can offer guidance for more extensive and in-depth studies in the future.

A physiologically based pharmacokinetic model of clopidogrel in populations of European and Japanese ancestry: An evaluation of CYP2C19 activity

Treatment response to clopidogrel is associated with CYP2C19 activity through the formation of the active H4 metabolite. The aims of this study were to develop a physiologically based pharmacokinetic (PBPK) model of clopidogrel and its metabolites for populations of European ancestry, to predict the pharmacokinetics in the Japanese population by CYP2C19 phenotype, and to investigate the effect of clinical and demographic factors. A PBPK model was developed and verified to describe the two metabolic pathways of clopidogrel (H4 metabolite, acyl glucuronide metabolite) for a population of European ancestry using plasma data from published studies. Subsequently, model predictions in the Japanese population were evaluated. The effects of CYP2C19 activity, fluvoxamine coadministration (CYP2C19 inhibitor), and population-specific factors (age, sex, BMI, body weight, cancer, hepatic, and renal dysfunction) on the pharmacokinetics of clopidogrel and its metabolites were then characterized. The predicted/observed ratios for clopidogrel and metabolite exposure parameters were acceptable (twofold acceptance criteria). For all CYP2C19 phenotypes, steady-state AUC0-τ of the H4 metabolite was lower for the Japanese (e.g., EM, 7.69 [6.26-9.45] ng·h/ml; geometric mean [95% CI]) than European (EM, 24.8 [20.4-30.1] ng·h/ml, p < .001) population. In addition to CYP2C19-poor metabolizer phenotype, fluvoxamine coadministration, hepatic, and renal dysfunction were found to reduce H4 metabolite but not acyl glucuronide metabolite concentrations. This is the first PBPK model describing the two major metabolic pathways of clopidogrel, which can be applied to populations of European and Japanese ancestry by CYP2C19 phenotype. The differences between the two populations appear to be determined primarily by the effect of varying CYP2C19 liver activity.

Pharmacogenomics Informs Cardiovascular Pharmacotherapy

Precision medicine exemplifies the emergence of personalized treatment options which may benefit specific patient populations based upon their genetic makeup. Application of pharmacogenomics requires an understanding of how genetic variations impact pharmacokinetic and pharmacodynamic properties. This particular approach in pharmacotherapy is helpful because it can assist in and improve clinical decisions. Application of pharmacogenomics to cardiovascular pharmacotherapy provides for the ability of the medical provider to gain critical knowledge on a patient's response to various treatment options and risk of side effects.

Clinical and pharmacological parameters determine relapse during clopidogrel treatment of acute coronary syndrome

The therapeutic efficacy of clopidogrel as an anti-platelet drug varies among individuals, being the mainstream hypothesis that its bioavailability depends on the individual genetic background and/or interactions with other drugs. A total of 477 patients receiving double anti-aggregation therapy with aspirin and clopidogrel, after suffering a first event, were followed for 1 year to record relapse, as a surrogate end point to measure their therapeutic response, as defined by presenting with an acute coronary event (unstable angina, STEMI, or NSTEMI), stent thrombosis/restenosis or cardiac mortality. Anthropometric, clinical and pharmacological variables along with CYP2C19 genotypes were analyzed for their association with the disease relapse phenotype. Only 75 patients (15%) suffered a relapse, which occurred during the first six months of therapy, with a peak at 4.5 months. An initial univariate analysis identified that patients in the relapse group were significantly older (67.4 ± 11.0 vs 61.6 ± 12.3 years old) and presented with diffuse coronary disease, insulin-dependent type 2 diabetes mellitus dyslipidemia, and arterial hypertension. A poor clinical response to the platelet anti-aggregation regime also occurred more frequently among patients taking, along with aspirin and clopidogrel, acenocoumarol and Calcium Channel Blockers, while no association was found according to CYP2C19 genotypes. A retrospective multivariate analysis indicated that patients belonging to the non-responder phenotype to treatment with aspirin and clopidogrel were older, presented with diffuse coronary disease, a group largely overlapping with type 2 insulin-dependent diabetes mellitus, and were taking dihidropyrimidinic calcium channel blockers. This article is protected by copyright. All rights reserved.

Personalized medicine in cardiovascular disease: review of literature

Purpose

Personalized medicine (PM) is the concept of managing patients based on their characteristics, including genotypes. In the field of cardiology, advantages of PM could be found in the diagnosis and treatment of several conditions such as arrhythmias and cardiomyopathies; moreover, it may be beneficial to prevent adverse drug reactions (ADR) and select the best medication. Genetic background can help us in selecting effective treatments, appropriate dose requirements, and preventive strategies in individuals with particular genotypes.

Method

In this review, we provide examples of personalized medicine based on human genetics for the most used pharmaceutics in cardiology, including warfarin, clopidogrel, and statins. We also review cardiovascular diseases, including coronary artery disease, arrhythmia, and cardiomyopathies.

Conclusion

Genetic factors are as important as environmental factors and they should be tested and evaluated more in the future by improving in genetic testing tools.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-021-00840-0.

Candidate Gene of NOS3, MMP3, AGT, and AGT1R and Pathway Analyses for Platelet Reactivity and Clinical Outcomes of Repeat Revascularization After First PCI in Chinese Patients

PURPOSE

Major disadvantages of the percutaneous coronary intervention (PCI) are the high occurrence of repeat revascularization due to restenosis and disease progression. The current study aimed to identify indicators that can predict the risk of repeat revascularization.

METHODS

A total of 143 patients who underwent PCI and had genetic test results were enrolled. We retrospectively reviewed their medical records after the first PCI. P2Y12 reaction unit (PRU) test results were obtained by VerifyNow; 4 candidate genes (NOS3, MMP3, AGT, and AGT1R) and 380 genes related to platelet activation-related processes and clopidogrel activity were selected for analysis. Repeat revascularization and in-stent restenosis (ISR) were used as clinical outcomes, and PRU and ADP aggregation rates were used as platelet function outcomes in analysis.

RESULTS

After the first PCI, the incidence of repeat revascularization at 18, 30, and 42 months was 14.1% (20/142), 17.5% (24/137), and 39.7% (31/78), respectively. In the candidate gene analysis, rs7830 (NOS3) was associated with both ADP aggregation rate and 18- and 30-month ISR, and rs 62,275,847 (AGTR1) was associated with both ADP aggregation rate and 30-month ISR. In the pathway, gene-set analysis, the linkage rs471683 and rs7785386 of GNAI1|GNAT3 were associated with PRU and ADP aggregation rate, 18-month and 30-month ISR, and repeat revascularization within 30 months. Rs1715389 of GNAI1|GNAT3 was associated with both PRU and ADP aggregation rate, 18-month and 30-month ISR, and repeat revascularization within 30 months. Rs7313458 of ITPR2 was associated with PRU and ADP aggregation rate, 18-month and 30-month ISR, and repeat revascularization within 18 months.

CONCLUSIONS

The genetic polymorphisms of rs7830 (NOS3), rs62275874 (AGTR1), linkage rs471683 and rs7785386 (GNAI1|GNAT3), rs1715389 (GNAI1|GNAT3), and rs7313458 (ITPR2) may lead to an increased risk of in-stent restenosis and revascularization after the first PCI in Chinese patients by affecting the efficacy of clopidogrel. The above six SNP may be used as potential genetic biomarkers for high risk of in-stent restenosis and revascularization after the first PCI in Chinese patients.

Association between Paraoxonase-1 p.Q192R Polymorphism and Coronary Artery Disease susceptibility in the Colombian Population

Background

Paraoxonase-1 (PON1), a glycoprotein associated with serum high-density lipoprotein (HDL), has a central role in metabolizing lipid peroxides, exhibiting antiatherogenic properties. The polymorphism p.Q192R has been previously associated with coronary artery disease (CAD) susceptibility and clopidogrel response.

Purpose

We aimed at investigating the association of PON1 p.Q192R with CAD and clopidogrel response in Colombian population.

Patients and Methods

The study was conducted among 163 patients diagnosed with CAD and treated with clopidogrel. The allele frequencies for the PON1 192Q and 192R alleles were determined in cases and Latin-American controls obtained from the public database gnomAD (n = 17,711). Response to clopidogrel was determined by assessing the platelet function using the INNOVANCE PFA-200 System. We determined the association between PON1 p.Q192R polymorphism, increased susceptibility to CAD and high on-treatment platelet reactivity (HPR) by using odds ratio (OR) and 95% confidence interval (CI) on four genetic models.

Results

The allele frequencies for the PON1 192Q and 192R alleles were 0.60 and 0.40, respectively. The allele distribution was found to be statistically different from the control group and other ethnic groups. The allele 192R was positively associated with decreased susceptibility to CAD under a dominant model (OR, 0.58; 95% CI, 0.42–0.8; P < 0.01). We found no association between the polymorphism and HPR.

Conclusion

We propose that PON1 p.Q192R is a potentially useful marker for CAD susceptibility in the Colombian population and lacks association with HPR under clopidogrel treatment.

Pharmacokinetics and Pharmacodynamics of Approved and Investigational P2Y12 Receptor Antagonists

Coronary artery disease remains the major cause of mortality worldwide. Antiplatelet drugs such as acetylsalicylic acid and P2Y12 receptor antagonists are cornerstone treatments for the prevention of thrombotic events in patients with coronary artery disease. Clopidogrel has long been the gold standard but has major pharmacological limitations such as a slow onset and long duration of effect, as well as weak platelet inhibition with high inter-individual pharmacokinetic and pharmacodynamic variability. There has been a strong need to develop potent P2Y12 receptor antagonists with more favorable pharmacological properties. Prasugrel and ticagrelor are more potent and have a faster onset of action; however, they have shown an increased bleeding risk compared with clopidogrel. Cangrelor is highly potent and has a very rapid onset and offset of effect; however, its indication is limited to P2Y12 antagonist-naïve patients undergoing percutaneous coronary intervention. Two novel P2Y12 receptor antagonists are currently in clinical development, namely vicagrel and selatogrel. Vicagrel is an analog of clopidogrel with enhanced and more efficient formation of its active metabolite. Selatogrel is characterized by a rapid onset of action following subcutaneous administration and developed for early treatment of a suspected acute myocardial infarction. This review article describes the clinical pharmacology profile of marketed P2Y12 receptor antagonists and those under development focusing on pharmacokinetic, pharmacodynamic, and drug-drug interaction liability.

Pharmacogenetics to guide cardiovascular drug therapy

Over the past decade, pharmacogenetic testing has emerged in clinical practice to guide selected cardiovascular therapies. The most common implementation in practice is CYP2C19 genotyping to predict clopidogrel response and assist in selecting antiplatelet therapy after percutaneous coronary intervention. Additional examples include genotyping to guide warfarin dosing and statin prescribing. Increasing evidence exists on outcomes with genotype-guided cardiovascular therapies from multiple randomized controlled trials and observational studies. Pharmacogenetic evidence is accumulating for additional cardiovascular medications. However, data for many of these medications are not yet sufficient to support the use of genotyping for drug prescribing. Ultimately, pharmacogenetics might provide a means to individualize drug regimens for complex diseases such as heart failure, in which the treatment armamentarium includes a growing list of medications shown to reduce morbidity and mortality. However, sophisticated analytical approaches are likely to be necessary to dissect the genetic underpinnings of responses to drug combinations. In this Review, we examine the evidence supporting pharmacogenetic testing in cardiovascular medicine, including that available from several clinical trials. In addition, we describe guidelines that support the use of cardiovascular pharmacogenetics, provide examples of clinical implementation of genotype-guided cardiovascular therapies and discuss opportunities for future growth of the field.

CYP2C19 genotype has prognostic value in specific populations following coronary stenting

Background

The prognostic value of the CYP2C19 genotype in post-percutaneous coronary intervention (PCI) patients remains controversial. The recently-published, limited-sample PHARMCLO trial indicates a personalized pharmacogenomic approach may reduce adverse events. This study aimed to determine the prognostic value of CYP2C19 genotypes.

Methods

The original cohort consisted of 10,724 PCI patients in 2013. 756 patients with genotyped CYP2C19 were included in our analysis. The CYP2C19 genotype prognostic value was tested based on different clinical factors. The primary endpoint was major adverse cardio- and cerebro-vascular event (MACCE).

Results

MACCE 2-years post-PCI occurred in 19 patients (17.4%) in poor metabolizers (PM, CYP2C19 *2/*2, *2/*3, *3/*3), 43 patients (12.2%) in intermediate metabolizers (IM, CYP2C19 *1/*2 or *1/*3) and 27 patients (9.2%) in extensive metabolizers (EM, CYP2C19 *1/*1). PM was an independent MACCE predictor compared with EM (HR: 1.960, 95% CI: 1.139–3.372), but the difference between IM and PM was not significant (HR: 1.314, 95% CI: 0.843–2.048). Major bleeding (BARC grade ≥3) was not significantly different between the three groups (2.5% vs. 2.1% vs. 0.8%, P=0.133). Subgroup analysis showed that the CYP2C19 genotype prognostic value was present in the following subgroups: male, age >60 years, body mass index (BMI) >24 kg/m², SYNTAX score >15, current smokers, and patients without chronic kidney disease.

Conclusions

Utilizing CYP2C19 genotype to guide post-PCI antiplatelet therapy might be appropriate in patients with the following characteristics: male, age >60 years, BMI >24 kg/m², SYNTAX score >15, current smokers, and non-chronic kidney disease (CKD) patients.

The impact of catha edulis (vahl) forssk. ex endl. (celestraceae) (khat) on pharmacokinetics of clinically used drugs

INTRODUCTION

Catha edulis (Vahl) Forssk. ex Endl. (Celestraceae) is used as a recreational drug on daily basis for its euphoric and psychostimulant effects. It is also chewed by individuals who are on medications, raising the possibility of drug-khat interaction. However, limited data are available in the literature, although clinically significant interactions are expected, as khat contains a complex mixture of pharmacologically active constituents.

AREAS COVERED

It provides an overview of the phytochemistry, pharmacokinetics, pharmacodynamics, and pharmacogenetics of khat based on the literature mined from PubMed, Google Scholar, and Cochrane databases. It also presents a detailed account of drug-khat interactions with specific examples and their clinical significance. The interactions mainly occur at the pharmacokinetics level and particular attention is paid for the phases of absorption and cytochrome P450 enzyme-mediated metabolism.

EXPERT OPINION

Despite the increasing trend of khat chewing with medications among the populace and the potential risk for the occurrence of clinically significant interactions, there is paucity of data in the literature demonstrating the magnitude of the risk. The available data, however, clearly demonstrate that the consequence of drug-khat interaction is dependent on genotype. Genotyping, where feasible, could be used to improve clinical outcome and minimize adverse reactions.

Cardiovascular Pharmacogenomics: An Update on Clinical Studies of Antithrombotic Drugs in Brazilian Patients

Anticoagulant and antiplatelet drugs effectively prevent thrombotic events in patients with cardiovascular diseases, ischemic stroke, peripheral vascular diseases, and other thromboembolic diseases. However, genetic and non-genetic factors affect the response to antithrombotic therapy and can increase the risk of adverse events. This narrative review discusses pharmacogenomic studies on antithrombotic drugs commonly prescribed in Brazil. Multiple Brazilian studies assessed the impact of pharmacokinetic (PK) and pharmacodynamic (PD) gene variants on warfarin response. The reduced function alleles CYP2C9*2 and CYP2C9*3, and VKORC1 rs9923231 (c.-1639G>A) are associated with increased sensitivity to warfarin and a low dose requirement to prevent bleeding episodes, whereas CYP4F2 rs2108622 (p.Val433Met) carriers have higher dose requirements (warfarin resistance). These deleterious variants and non-genetic factors (age, gender, body weight, co-administered drugs, food interactions, and others) account for up to 63% of the warfarin dose variability. Few pharmacogenomics studies have explored antiplatelet drugs in Brazilian cohorts, finding associations between CYP2C19*2, PON1 rs662 and ABCC3 rs757421 genotypes and platelet responsiveness or clopidogrel PK in subjects with coronary artery disease (CAD) or acute coronary syndrome (ACS), whereas ITGB3 contributes to aspirin PK but not platelet responsiveness in diabetic patients. Brazilian guidelines on anticoagulants and antiplatelets recommend the use of a platelet aggregation test or genotyping only in selected cases of ACS subjects without ST-segment elevation taking clopidogrel, and also suggest CYP2C9 and VKORC1 genotyping before starting warfarin therapy to assess the risk of bleeding episodes or warfarin resistance.

PON1 Q192R is associated with high platelet reactivity with clopidogrel in patients undergoing elective neurointervention: A prospective single-center cohort study

Background and purpose

The impact of the paraoxonase-1 (PON1) polymorphism, Q192R, on platelet inhibition in response to clopidogrel remains controversial. We aimed to investigate the association between carrier status of PON1 Q192R and high platelet reactivity (HPR) with clopidogrel in patients undergoing elective neurointervention.

Methods

Post-clopidogrel platelet reactivity was measured using a VerifyNow^® P2Y12 assay in P2Y12 reaction units (PRU) for consecutive patients before the treatment. Genotype testing was performed for PON1 Q192R and CYP2C19*2 and *3 (no function alleles), and *17. PRU was corrected on the basis of hematocrit. We investigated associations between factors including carrying ≥1 PON1 192R allele and HPR defined as original and corrected PRU ≥208.

Results

Of 475 patients (232 men, median age, 68 years), HPR by original and corrected PRU was observed in 259 and 199 patients (54.5% and 41.9%), respectively. Carriers of ≥1 PON1 192R allele more frequently had HPR by original and corrected PRU compared with non-carriers (91.5% vs 85.2%, P = 0.031 and 92.5% vs 85.9%, P = 0.026, respectively). In multivariate analyses, carrying ≥1 PON1 192R allele was associated with HPR by original (odds ratio [OR] 1.96, 95% confidence interval [CI] 1.03–3.76) and corrected PRU (OR 2.34, 95% CI 1.21–4.74) after adjustment for age, sex, treatment with antihypertensive medications, hematocrit, platelet count, total cholesterol, and carrying ≥1 CYP2C19 no function allele.

Conclusions

Carrying ≥1 PON1 192R allele is associated with HPR by original and corrected PRU with clopidogrel in patients undergoing elective neurointervention, although alternative results related to other genetic polymorphisms cannot be excluded.

Risk of stroke in CYP2C19 LoF polymorphism carrier coronary artery disease patients undergoing clopidogrel therapy: An ethnicity-based updated meta-analysis

BACKGROUND

Antiplatelet agent clopidogrel has been widely used for stroke management for many years, although resistance to clopidogrel may increase the chance of stroke recurrence. CYP2C19 loss-of-function (LoF) polymorphism is assumed to be responsible for the poor metabolism of clopidogrel that ultimately turns to resistance. Previous publications could not provide firm evidence due to highly conflicting and heterogeneous outcomes.

AIM

To get clear evidence from an updated meta-analysis on CYP2C19 LoF polymorphism association with stroke risk in clopidogrel treated patients, this study has been performed.

METHODS

We conducted a meta-analysis with 72 selected studies from authentic databases, including 40,035 coronary artery disease patients treated with clopidogrel.

RESULTS

This analysis showed that the worldwide carrier of one or more CYP2C19 LoF alleles had a significantly higher risk of stroke and composite events than the non-LoF carriers (RR=1.78, 95% CI=1.52-2.07, p<0.00001 and RR=1.39, 95% CI=1.26-1.54, p<0.00001, respectively). Besides, subgroup analysis showed that Asian CYP2C19 LoF carriers had a significantly increased risk of stroke (RR=1.91, 95% CI=1.60-2.28, p<0.00001) while the risk of composite events was significantly higher in all ethnic populations (Asian: RR=1.58, 95% CI=1.32-1.89, p<0.00001; Caucasian: RR=1.27, 95% CI=1.08-1.50, p=0.003; Hispanic and others: RR=1.21, 95% CI=1.09-1.34, p=0.0003).

CONCLUSION

Our meta-analysis confirmed that the presence of CYP2C19 LoF alleles increases the risk of stroke and composite events recurrence in the worldwide population, especially in Asians undergoing clopidogrel treatment. Alternative antiplatelet therapy should be investigated thoroughly for the intermediate and poor metabolizers.

New genetic variants associated with major adverse cardiovascular events in patients with acute coronary syndromes and treated with clopidogrel and aspirin

Although a few studies have reported the effects of several polymorphisms on major adverse cardiovascular events (MACE) in patients with acute coronary syndromes (ACS) and those undergoing percutaneous coronary intervention (PCI), these genotypes account for only a small fraction of the variation and evidence is insufficient. This study aims to identify new genetic variants associated with MACE end point during the 18-month follow-up period by a two-stage large-scale sequencing data, including high-depth whole exome sequencing of 168 patients in the discovery cohort and high-depth targeted sequencing of 1793 patients in the replication cohort. We discovered eight new genotypes and their genes associated with MACE in patients with ACS, including MYOM2 (rs17064642), WDR24 (rs11640115), NECAB1 (rs74569896), EFR3A (rs4736529), AGAP3 (rs75750968), ZDHHC3 (rs3749187), ECHS1 (rs140410716), and KRTAP10-4 (rs201441480). Notably, the expressions of MYOM2 and ECHS1 are downregulated in both animal models and patients with phenotypes related to MACE. Importantly, we developed the first superior classifier for predicting 18-month MACE and achieved high predictive performance (AUC ranged between 0.92 and 0.94 for three machine-learning methods). Our findings shed light on the pathogenesis of cardiovascular outcomes and may help the clinician to make a decision on the therapeutic intervention for ACS patients.

Biomarkers for Antiplatelet Therapies in Acute Ischemic Stroke: A Clinical Review

Stroke is one of the world's leading causes of disability and death. Antiplatelet agents are administered to acute ischemic stroke patients as secondary prevention. Clopidogrel involves biotransformation by cytochrome P450 (CYP) enzymes into an active metabolite, and single nucleotide polymorphisms (SNPs) can influence the efficacy of this biotransformation. Despite the therapeutic advantages of aspirin, there is significant inter-individual heterogeneity in response to this antiplatelet drug. In this clinical review, the recent advances in the biomarkers of antiplatelet agents in acute ischemic stroke are discussed. The studies reviewed herein highlight the clinical relevance of antiplatelet resistance, pharmacotherapy of antiplatelet agents predicting drug response, strategies for identifying aspirin resistance, pharmacogenetic variants of antiplatelet agents, miRNAs, and extracellular vesicles (EVs) as biomarkers toward the personalized approach in the management of acute ischemic stroke. The precise pathways contributing to antiplatelet resistance are not very well known but are presumably multi-factorial. It is essential to understand the clinical relevance of clopidogrel and aspirin-related single nucleotide polymorphism (SNPs) as potential predictive and prognostic biomarkers. Prasugrel is a next-generation antiplatelet agent that prevents ADP-platelet activation by binding irreversibly to P2Y12 receptor. There are sporadic reports of prasugrel resistance and polymorphisms in the Platelet endothelial aggregation receptor-1 (PEAR1) that may contribute to a change in the pharmacodynamics response. Ticagrelor, a direct-acting P2Y12-receptor antagonist, is easily absorbed and partly metabolized to major AR-C124910XX metabolite (ARC). Ticagrelor's primary active metabolite, ARC124910XX (ARC), is formed via the most abundant hepatic cytochrome P450 (CYP) enzyme, CYP3A4, and CYP3A5. The integration of specific biomarkers, genotype as well as phenotype-related data in antiplatelet therapy stratification in patients with acute ischemic stroke will be of great clinical significance and could be used as a guiding tool for more effective, personalized therapy.

Impact of selected genetic factors on clopidogrel inactive metabolite level and antiplatelet response in patients after percutaneous coronary intervention

BACKGROUND AND OBJECTIVE

Clopidogrel is frequently used as part of optimal dual antiplatelet therapy in high-bleeding risk patients with the acute coronary syndrome. The concentration of the inactive carboxylic acid metabolite of clopidogrel might be useful to evaluate the response to clopidogrel therapy. Therefore, we sought to correlate the inhibition of platelet aggregation with the plasma level of the inactive metabolite of clopidogrel in patients after percutaneous coronary interventions (PCI) and their associations with the most frequently studied genetic polymorphisms. For this purpose, the fast and simple HPLC method for determining the concentration of the inactive metabolite was developed.

METHODS

The effect of CYP2C19, CYP3A4/5, ABCB1 and PON1 genes on the plasma inactive metabolite concentration of clopidogrel and the platelet aggregation was investigated in 155 patients before and after PCI.

RESULTS

The concentration of the inactive metabolite of clopidogrel was not significantly different in the intermediate metabolizers (IM) of CYP2C19 compared with extensive metabolizers (EM) both before and after PCI, while inhibition of platelet aggregation was found to be significantly better in EM than in IM. The presence of the A allele at position 2677 in the ABCB1 gene was associated with a significantly lower concentration of inactive metabolite of clopidogrel before PCI.

CONCLUSION

The CYP2C19*2 allele was associated with decreased platelet reactivity during clopidogrel therapy before and after PCI. Simultaneous determination of platelet aggregation and concentration of the inactive clopidogrel metabolite may be useful in clinical practice to find the cause of adverse effects or insufficient treatment effect in patients chronically treated with clopidogrel.

The disappearance of IPO in myocardium of diabetes mellitus rats is associated with the increase of succinate dehydrogenase-flavin protein

BACKGROUND

The aim of the present study was to investigate whether the disappearance of ischemic post-processing (IPO) in the myocardium of diabetes mellitus (DM) is associated with the increase of succinate dehydrogenase-flavin protein (SDHA).

METHODS

A total of 50 Sprague Dawley rats, weighing 300-400 g, were divided into 5 groups according to the random number table method, each with 10 rats. After DM rats were fed a high-fat and -sugar diet for 4 weeks, they were injected with Streptozotocin to establish the diabetic rat model. Normal rats were fed the same regular diet for the same number of weeks. Next, the above rats were taken to establish a cardiopulmonary bypass (CPB) model. Intraperitoneal glucose tolerance test (IPGTT) and oral glucose tolerance test (OGTT) were used to detect whether the DM rat model was established successfully. Taking blood from the femoral artery to collect the blood-gas analysis indicators, and judged whether the CPB model is established. After perfusion was performed according to the experimental strategy, the area of myocardial infarction (MI), and serum creatine kinase isoenzyme (CK-MB) and cardiac troponin (CTnI) levels were measured. Finally, the relative mRNA and protein expression of SDHA was detected.

RESULTS

The OGTT and IPGTT suggested that the DM rat model was successfully established. The arterial blood gas analysis indicated that the CPB model was successfully established. As compared with the N group, the heart function of the IR group was significantly reduced, the levels of myocardial enzyme markers, the area of MI, as well as the relative mRNA and protein expression of SDHA, were all increased. As compared with the IR group, the CK-MB and CTnI levels in the IPO group, the MI area, relative mRNA and protein expression of SDHA decreased. As compared with the IPO group, the myocardial enzyme content in the DM + IPO group, the MI area and the relative mRNA and protein expression of SDHA increased. As compared with the DM + IPO group, in the DM + IPO + dme group, the myocardial enzyme content, area of MI and relative mRNA and protein expression were all decreased.

CONCLUSION

IPO can inhibit the expression of SDHA, reduce MIRI and exert a cardioprotective effect in the normal rats. However, the protective effect of IPO disappears in the diabetic rats. The inhibitor dme combined with IPO can increase the expression of SDHA and restore the protective effect of IPO in DM myocardia.

Effects of clopidogrel, prasugrel and ticagrelor on prevention of stent thrombosis in patients underwent percutaneous coronary intervention: A network meta-analysis

Background

Clopidogrel, prasugrel and ticagrelor, acting on platelet P2Y12 receptor, are commonly used for prevention of stent thrombosis (ST) among patients who underwent percutaneous coronary intervention (PCI). This study aimed to compare the effects of these drugs by a systematic review and network meta‐analysis.

Hypothesis

Efficacies of clopidogrel, prasugrel and ticagrelor on preventing ST are not the same.

Methods

PubMed, Embase and Cochrane Library were searched for randomized controlled trials (RCTs) that investigated the effect of clopidogrel, prasugrel, or ticagrelor on prevention of ST in patients who underwent PCI. The efficacies between groups were compared by a Bayesian network meta‐analysis, by which the pooled odds ratios (ORs) and 95% confidence intervals (CIs) was calculated.

Results

Fourteen studies and 46 983 participants were included in this study. The pooled results illustrated that clopidogrel, prasugrel and ticagrelor were effective on prevention of ST. Patients treated with prasugrel (OR = 0.30, 95% CI = 0.052 ~ 0.73, P < 0.05) and ticagrelor (OR = 0.25, 95% CI = 0.035 ~ 0.65, P < 0.05) had lower incidence of ST compared to those treated with clopidogrel. Patients treated with ticagrelor showed similar frequency with those in prasugrel group (OR = 0.86, 95% CI = 0.22 ~ 2.3, P > 0.05). No significant heterogeneity was observed across included studies.

Conclusions

Our findings suggest that prasugrel and ticagrelor are more effective than clopidogrel on prevention of ST among patients underwent PCI. Simultaneously, there is no significant difference in the prevention of ST between prasugrel and ticagrelor.

The Relevance of Noncoding DNA Variations of Paraoxonase Gene Cluster in Atherosclerosis-Related Diseases

The human paraoxonase (PON) gene cluster is comprised of three contiguous genes (PON1, PON2 and PON3) of presumably common origin coding three lactonases of highly similar structure and substrate specificity. The catalytic activity of PON proteins is directed toward artificial organophosphates and in physiological conditions toward thiolactones and oxidized phospholipids. Consequently, PON enzymes are regarded as an effective defense against oxidative stress and, as a result, against atherosclerosis development. Additionally, both PON's serum activity and its concentration are influenced by several polymorphic variations in coding and noncoding DNA regions of the PON gene cluster remaining in linkage disequilibrium. Hence, the genetic polymorphism of the PON gene cluster may contribute to atherosclerotic process progression or deceleration. In this review the authors analyzed the relevance of noncoding DNA polymorphic variations of PON genes in atherosclerosis-related diseases involving coronary and peripheral artery disease, stroke, diabetes mellitus, dementia and renal disease and concluded that the effect of PON gene cluster' polymorphism has a considerable impact on the course and outcome in these conditions. The following PON genetic variations may serve as additional predictors of the risk of atherosclerosis in selected populations and individuals.

Impact of genetic variants on major bleeding after percutaneous coronary intervention based on a prospective multicenter registry

Although dual antiplatelet therapy is essential for patients who undergo percutaneous coronary interventions, the risk of bleeding remains an unsolved problem, and there is limited information on the potential relationship between genetic variants and major bleeding. We analyzed the correlations between four major single nucleotide polymorphisms (CYP2C19, ABCB1, PON1, and P2Y12 G52T polymorphisms) and clinical outcomes in 4489 patients from a prospective multicenter registry. The primary endpoint was major bleeding, defined as a Bleeding Academic Research Consortium ≥ 3 bleeding event. The allelic frequencies of ABCB1, PON1, and both individual and combined CYP2C19 variants did not differ significantly between patient groups with and without major bleeding. However, the allelic frequency of the P2Y12 variant differed significantly between the two groups. Focusing on the P2Y12 G52T variant, patients in the TT group had a significantly higher rate of major bleeding (6.4%; adjusted hazard ratio [HR] 2.51; 95% confidence interval [CI] 1.08-5.84; p = 0.033) than patients in the other groups (GG [2.9%] or GT [1.9%]). Therefore, the TT variant of the P2Y12 G52T polymorphism may be an independent predictor of major bleeding.Trial registration: NCT02707445 ( https://clinicaltrials.gov/ct2/show/NCT02707445?term=02707445&draw=2&rank=1 ).

MirSNPs in clopidogrel metabolism genes predict cardiovascular disease risk: a case-control study and meta-analysis

Aim: The present study was conducted to decipher the inter-relationship of SNPs and miRNAs involved in pharmacogenomics of clopidogrel on predisposition to cardiovascular diseases (CVDs). Materials & methods: A case-control study was conducted on 410 cases and 386 controls to analyze the association of 13 mirSNPs on CVDs risk. Genotyping was performed by tetra-primer amplification refractory mutation system PCR and validated using Sanger DNA sequencing. miRNA expression analysis was performed using TaqMan assays. A meta-analysis was performed for PON1 rs662 with coronary artery disease. Results & conclusion: PON1 rs662, PON1 rs3917577, CYP3A5 rs15524, COL4A1 rs874204 and PTGIR rs1126510 polymorphisms showed association with CVDs. The miRNA hsa-miR-224-5p showed differential expression in the PON1 rs3917577 GG genotype. The meta-analysis showed the population-specific impact of PON1 rs662 on South Asian and Middle East populations.

Pharmacokinetic, pharmacodynamic, and pharmacogenetic assays to monitor clopidogrel therapy

Clopidogrel is the most common and widely used antiplatelet agent for patients with coronary artery disease following confirmation by electrocardiographic studies. The nonresponsiveness of patients to clopidogrel and the possibility of testing for clopidogrel resistance by platelet function assays (PFA) are contentious issues. Light transmission aggregometry (LTA) is considered as the gold standard test among all PFA. In this review, the most commonly used PFA used for monitoring the effect of clopidogrel, LTA, vasodilator-stimulated phosphoprotein assay phosphorylation, rotational thromboelastometry (ROTEM) delta and ROTEM platelet, thromboelastography, PFA-100, VerifyNow P2Y12 assay, Multiplate analyzer, Plateletworks assay and pharmacogenetic studies, are comparatively discussed including their principles of action, advantages, and disadvantages. VerifyNow P2Y12 assay can be accepted as the ideal point of care test out of the discussed assays. However, modified assays are required which could overcome the limitations associated with currently available assays.

Genetic Polymorphisms and Perioperative Bleeding in Off-Pump Coronary Artery Bypass Grafting Surgery

BACKGROUND

Clopidogrel use before coronary artery bypass graft surgery may increase risk for perioperative hemorrhage. The effect of genetic polymorphisms related to clopidogrel responses on bleeding during or after off-pump coronary artery bypass graft surgery is unknown.

METHODS

This prospective study included 206 coronary artery disease patients scheduled for off-pump coronary artery bypass graft surgery. Genotypes were determined using Sequenom MassARRAY system. Severe bleeding was defined by the universal definition of perioperative bleeding in cardiac surgery.

RESULTS

Patients carrying the ABCB1 3435 wild-type genotype (CC) had a higher risk of severe perioperative bleeding compared with patients carrying the variant genotype (CT or TT; 33.9% vs 16.5%, P = .009). Low baseline hemoglobin level (odds ratio 0.944; 95% confidence interval, 0.917 to 0.972; P < .001), low baseline estimated glomerular filtration rate (odds ratio 0.977; 95% confidence interval, 0.956 to 0.999; P = .041), discontinuing clopidogrel 5 days or less before surgery (odds ratio 2.458; 95% confidence interval, 1.044 to 5.786; P = .039), and the ABCB1 wild-type genotype (CC; odds ratio 2.941; 95% confidence interval, 1.250 to 6.944; P = .014) were independent risk factors for severe perioperative bleeding.

CONCLUSIONS

Patients carrying the ABCB1 wild-type genotype (CC) had a higher rate of severe perioperative bleeding compared with patients carrying the variant genotype (CT or TT). Discontinuation of clopidogrel 5 days or less before surgery and the ABCB1 wild-type genotype (CC) were independent risk factors for severe perioperative bleeding.

Clopidogrel drug interactions: a review of the evidence and clinical implications

INTRODUCTION

Patients with cardiovascular disease are commonly affected by a number of comorbidities leading to a high prevalence of polypharmacy. Polypharmacy increases the probability of drug-drug interactions (DDIs). Amongst these, DDIs involving clopidogrel, the most commonly utilized platelet P2Y₁₂ inhibitor, is a topic of potential clinical concern.

AREAS COVERED

This article reviews DDIs between clopidogrel and drugs which are widely used in clinical practice. In particular, drugs shown to interfere with the pharmacodynamic and pharmacokinetic effects of clopidogrel and the clinical implications of these findings are reviewed. These drugs include inhibitors of gastric acid secretion, statins, calcium channel blockers, antidiabetic agents, and antimicrobial agents. For the references, we searched PubMed, EMBASE, or the Cochrane Library.

EXPERT OPINION

Clopidogrel-drug interactions are common. Most of these DDIs are limited to laboratory findings showing an impact on clopidogrel-induced antiplatelet effects. While variability in clopidogrel-induced antiplatelet effects is known to affect clinical outcomes, with high platelet reactivity being associated with thrombotic complications among patients undergoing coronary stenting, most studies assessing the clinical implications of clopidogrel-drug interactions have not shown to significantly affect outcomes. However, awareness of these DDIs remains important for optimizing the selection of concomitant therapies.

Distribution of CYP2C19, ABCB1 and PON1 polymorphisms in Chinese Han, Hui, Uygur and Kazak patients with coronary atherosclerotic heart disease

CYP2C19, ABCB1 and PON1 polymorphisms involve in the metabolism and absorption of clopidogrel, which may be associated with interethnic variability of clopidogrel response. In our study, we evaluated the prevalence of CYP2C19, ABCB1 and PON1 single nucleotide polymorphisms (SNP) in patients with coronary atherosclerotic heart disease (CHD) of Chinese Han, Hui, Uygur and Kazak ethnic groups. Five SNPs were detected [CYP2C19 ∗2 (rs4244285), CYP2C19 ∗3 (rs4986893), CYP2C19 ∗17 (rs12248560), ABCB1 (rs1045642) and PON1 (rs662)]. The analysis was performed in 1,337 patients with CHD, including 831 Han, 85 Hui, 352 Uygur and 69 Kazak. The results revealed the differential distribution of the five SNPs. Frequencies of CYP2C19 no function variants in Uygur and Kazak were lower than those in Han and Hui groups (P < .05). CYP2C19 variants with increased function were more common in Uygur (13.6%) and Kazak (10.9%) groups (P < .05). Compared with Han and Hui groups, distribution of ABCB1 allele T was more prevalent in Uygur and Kazak groups (53.8% and 50.7%, respectively, P < .05). PON1 allele A frequencies of 55.7% and 58.7% in Uygur and Kazak showed higher prevalence than in the Han (38.4%) and Hui (43.5%) groups (P < .05). In conclusion, CYP2C19 *2 and *3 alleles are prevalent in Chinese Han and Hui groups, whereas CYP2C19 *17, ABCB1 T and PON1 A variants are relatively frequent in Chinese Uygur and Kazak ethnic groups. Our findings may provide a theoretical basis for the explanation of ethnic differences in determining clinical therapy strategies and predicting adverse effects.

Application of Genome-Wide Association Studies in Coronary Artery Disease

Coronary artery disease (CAD) is a complex disease caused by the combination of environmental and genetic factors. It is one of the leading causes of death and disability in the world. Much research has been focussed on CAD genetic mechanism. In recent years, genome-wide association study (GWAS) has developed rapidly around the world. Medical researchers around the world have successfully discovered a series of CAD genetic susceptibility genes or susceptible loci using medical research strategies, leading CAD research toward a new stage. This paper briefly summarizes the important progress made by GWAS for CAD in the world in recent years, and then analyzes the challenges faced by GWAS at this stage and the development trend of future research, to promote the transformation of genetic research results into clinical practice and provide guidance for further exploration of the genetic mechanism of CAD.

Genetic polymorphisms of high platelet reactivity in Chinese patients with coronary heart disease under clopidogrel therapy

BACKGROUND

The variability in the clinical response to clopidogrel treatment has been attributed to genetic factors, but the specific genes and other risk factors remain unclear.

OBJECTIVE

To investigate the incidence of high on-treatment platelet reactivity in coronary heart disease patients following clopidogrel therapy by analyzing the correlation between genetic polymorphisms and high on-treatment platelet reactivity.

SETTING

This study was conducted in the Chinese People's Liberation Army (PLA) general hospital.

METHOD

578 patients with coronary heart disease undergoing percutaneous transluminal coronary intervention treatment were enrolled. They received dual antiplatelet therapy with aspirin (300 mg) plus clopidogrel (300 mg) over 24 h, or aspirin (100 mg/day) and clopidogrel (75 mg/day) over 3 days. Patients were divided into two groups according to the adenosine diphosphate inhibition rate. The follow-up lasted at least 12 months and adverse endpoint events were recorded.

MAIN OUTCOME MEASURE

The single nucleotide polymorphisms were detected by MassArray genotyping system.

RESULTS

The incidence of HTPR was 15.74% in total, being higher in females than in males (24.29% vs. 13.01%, P < 0.01). Diabetes mellitus, homocysteine and high sensitivity C-reactive protein (hs-CRP) levels were significantly higher in the HTPR group than those in the non-HTPR group (P < 0.05). Polymorphisms of rs1057910 (OR 2.90, P = 0.003), rs2246709 (OR 0.69, P = 0.039), and rs776746 (OR 0.66, P = 0.034) were associated with the incidence of high on-treatment platelet reactivity. Female patients were prone to polymorphisms of rs1057910 (OR 3.24, P = 0.004) and rs776746 (OR 0.57, P = 0.025). Compared to non-high on-treatment platelet reactivity group, no differences in high reactivity group were observed with coexisting single nucleotide polymorphisms (14.6% vs. 14.8%, P > 0.05). The adverse endpoint events were significantly higher in the high on-treatment platelet reactivity group than in the non-treatment reactivity group. The survival analysis showed that high on-treatment platelet reactivity was significantly associated with the risk of the endpoint events (P = 0.0219).

CONCLUSION

Gender (female), diabetes mellitus, high levels of homocysteine and hs-CRP were risk factors for high on-treatment platelet reactivity, and high reactivity was a strong predictor for adverse endpoint events in the coronary heart disease patients. The polymorphism of rs1057910 was a risk factor of high on-treatment platelet reactivity while rs2246709 and rs776746 polymorphisms were protective factors, and coexisting single nucleotide polymorphisms didn't increase the incidence of high on-treatment platelet reactivity.

Serum PON1 as a biomarker for the estimation of microvascular invasion in hepatocellular carcinoma

Background

Microvascular invasion (MVI) is considered as one of the most powerful prognostic factors in hepatocellular carcinoma (HCC). Currently, it could only be diagnosed by post-operative histological examination. This study aimed to assess the diagnostic value of serum paraoxonase 1 (PON1) for MVI.

Methods

In this study, we analyzed data from 754 HCC patients who underwent surgical treatment between December 2010 and November 2011. Serum PON1 was measured by ELISA and receiver operating characteristic (ROC) curve was applied to calculate diagnostic accuracy.

Results

MVI was detected in 174 of 505 patients (34.5%) in the test cohort and 84 of 249 patients (33.7%) in the validation cohort. Univariate analyses indicated tumor size, AFP, and PON1 were significantly related with vascular invasion status. ROC curves determined the optimum diagnostic cutoff value for PON1 was 191.12 ng/mL (AUC 0.754, 95% CI: 0.710-0.798, sensitivity 70.67%, specificity 78.11% in the test cohort), which was significantly better than AFP (cutoff value 279.8 ng/mL, AUC 0.666, 95% CI: 0.618-0.714, sensitivity 40.38%, specificity 85.19%, P=0.0063). In the sHCC sub-group, PON1 retained diagnostic value (AUC 0.738, 95% CI: 0.680-0.796, sensitivity 72.82%, specificity 76.57% in the test cohort), while AFP failed to do so (AUC 0.579, 95% CI: 0.511-0.647, sensitivity 26.21%, specificity 86.84%, P=0.0003). These results were further confirmed by the validation cohort. The combination of PON1 and AFP increased the diagnostic accuracy for vascular invasion compared with either test alone (AUC 0.785, 95% CI: 0.744-0.826, sensitivity 75.96%, specificity 77.44%; PON1 plus AFP vs. PON1 alone, P=0.0004; PON1 plus AFP vs. AFP alone, P<0.0001).

Conclusions

Serum PON1 could potentially be used to diagnose MVI and could be used to guide more personalized treatment strategy.

The impact of cytochrome 450 and Paraoxonase polymorphisms on clopidogrel resistance and major adverse cardiac events in coronary heart disease patients after percutaneous coronary intervention

Background

Clopidogrel is an inactive prodrug, it catalyzed into its active form by Cytochrome 450 and Paraoxonase-1(PON-1). polymorphisms of genes encoding these enzymes will affect the efficacy of Clopidogrel. The main objective of our study was to investigate the association of CYP2C19*2, CYP2C19*3 and PON-1Q192R polymorphisms with Clopidogrel resistance and major adverse cardiac events in Jin Hua district in the middle of Zhe Jiang Province in China.

Methods

One hundred sixty coronary heart disease patients with percutaneous coronary intervention, who were followed-up for 1 year, were enrolled in our study. These patients were co-administered aspirin 100 mg/d and clopidogrel 75 mg/d following a loading dose of 300 mg. The ADP-induced platelet aggregation rate was measured by Platelet aggregator. Genotypes of CYP2C19*2, CYP2C19*3, PON-1Q192R were determined using Sanger sequencing in all patients. Various clinical data were collected.

Results

The frequencies of CYP2C19*2, CYP2C19*3 and PON-1Q192R homozygous mutant genotypes were significantly lower in non-responders than those in responders. After for all variables, CYP2C19*2, CYP2C19*3 and PON-1Q192R independently increased the risk of clopidogrel resistance with adjusted ORs 46.65(95% CI,1.77–25.04; p = 0.005); 22.74(95% CI, 3.11–166.27; p = 0.002); 5.69 (95% CI,1.06–30.47; p = 0.042). Over a follow-up of 12 months, the incidence of major adverse cardiac events (MACE) in CYP2C19*1/*2, *1/*3, *2/*2, *2/*3 was significantly higher than no mutant genotype (18/40vs.2/63,3/9vs.2/63, 11/6vs.2/63, 7/1vs2/63, respectively). There was no significant correlation between PON-1Q192R mutant allele and MACE.

Conclusion

Our study was first time to report on CYP2C19 and PON-1 polymorphisms in Jin Hua population in the middle of Zhe Jiang province in China. The carriage of CYP2C19*2 or *3 mutant allele significantly reduced the platelet response to clopidogrel and increase the MACE. The carriage of PON-1 mutant allele also significantly reduced the platelet response to clopidogrel, but would not increase the major adverse cardiac events after 1 year follow-up.

Trial registration

ChiCTR, ChiCTR1800018316. Registered 11 September 2018 – prospective registered, http://www.chictr.org.cn/edit.aspx?pid=30927&htm=4.

The Molecular and Enzyme Kinetic Basis for Altered Activity of Three Cytochrome P450 2C19 Variants Found in the Chinese Population

BACKGROUND

There is a large inter-individual variation in cytochrome P450 2C19 (CYP2C19) activity. The variability can be caused by the genetic polymorphism of CYP2C19 gene. This study aimed to investigate the molecular and kinetics basis for activity changes in three alleles including CYP2C19*23, CYP2C19*24 and CYP2C19*25found in the Chinese population.

METHODS

The three variants expressed by bacteria were investigated using substrate (omeprazole and 3- cyano-7-ethoxycoumarin[CEC]) and inhibitor (ketoconazole, fluoxetine, sertraline and loratadine) probes in enzyme assays along with molecular docking.

RESULTS

All alleles exhibited very low enzyme activity and affinity towards omeprazole and CEC (6.1% or less in intrinsic clearance). The inhibition studies with the four inhibitors, however, suggested that mutations in different variants have a tendency to cause enhanced binding (reduced IC50 values). The enhanced binding could partially be explained by the lower polar solvent accessible surface area of the inhibitors relative to the substrates. Molecular docking indicated that G91R, R335Q and F448L, the unique mutations in the alleles, have caused slight alteration in the substrate access channel morphology and a more compact active site cavity hence affecting ligand access and binding. It is likely that these structural alterations in CYP2C19 proteins have caused ligand-specific alteration in catalytic and inhibitory specificities as observed in the in vitro assays.

CONCLUSION

This study indicates that CYP2C19 variant selectivity for ligands was not solely governed by mutation-induced modifications in the active site architecture, but the intrinsic properties of the probe compounds also played a vital role.

Cytochrome 2C19 and paraoxonase-1 polymorphisms and clopidogrel resistance in ischemic heart disease patients

Aim: Polymorphisms in cytochrome P450 (CYP) 2C19 and paraoxonase-1 (PON-1) genes are thought to be involved in clopidogrel high on treatment reactivity in ischemic heart disease (IHD) patients. Methods: A total of 240 patients with IHD were screened for CYP2C19 loss-of-function alleles (LOF; *2, *3) and PON-1 Q192R. Patients were classified as responders and nonresponders to clopidogrel based upon platelet aggregation studies. Genotyping of the CYP2C19 and PON-1 allele was carried out by PCR-RFLP. Results: Results showed that 14.3% of the patients were nonresponders, whereas 85.7% were responders to the clopidogrel therapy. CYP2C19*3 allele showed significant association with clopidogrel high on treatment reactivity in IHD patients. Conclusion: Result of our study demonstrate that IHD patients with CYP2C19*3 allele can face the problem of clopidogrel high on treatment reactivity in Punjabi Pakistani population.

Effects of PON1 Gene Promoter DNA Methylation and Genetic Variations on the Clinical Outcomes of Dual Antiplatelet Therapy for Patients Undergoing Percutaneous Coronary Intervention

INTRODUCTION AND OBJECTIVE

The relationship between either paraoxonase 1 (PON1) gene promoter DNA methylation or genetic variations and bleeding or major adverse cardiac events after dual antiplatelet therapy has been incompletely characterized. We aimed to systematically investigate the role of genetic variations and DNA methylation of the PON1 CpG island promoter on the clinical outcomes of dual antiplatelet therapy for patients with coronary artery disease (CAD) who underwent percutaneous coronary intervention (PCI).

METHODS

This study included 653 patients with CAD undergoing PCI and receiving dual antiplatelet therapy. Genomic DNAs were isolated from whole blood and were genotyped for the three single nucleotide polymorphisms (SNPs) of the PON1 gene. The DNA methylation levels in the PON1 promoter region were determined by bisulfite sequencing or pyrosequencing at five CpG sites (positions -142, -161, -163, -170, and -184 from the transcription start site). Clopidogrel and its metabolites in plasma were examined using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and platelet function analysis was performed using the VerifyNow assay.

RESULTS

Statistically significant associations between methylation levels at five PON1 CpG sites and bleeding were observed: -184 [odds ratio (OR) 0.98, 95% confidence interval (CI) 0.96-1.00, p = 0.028]; -170 (OR 0.99, 95% CI 0.97-1.00, p = 0.048); -163 (OR 0.98, 95% CI 0.96-1.00, p = 0.029); -161 (OR 0.98, 95% CI 0.97-1.00, p = 0.026); and -142 (OR 0.98, 95% CI 0.97-1.00, p = 0.042) at a false discovery rate of <5%. Statistical analysis also revealed that aspirin reaction units (ARUs) were significantly associated with PON1 methylation level at CpG site -163 (p = 0.0342). The ARUs of patients with the PON1 126 CC genotype was 527 ± 94, which was higher than the ARUs (473 ± 89) of patients with the 126 CG genotype (p = 0.0163). Multivariate logistic regression analysis indicated that the PON1 methylation level at CpG site -161 (OR 0.95, 95% CI 0.92-0.98, p = 0.002) and the use of angiotensin-converting enzyme inhibitors (OR 0.48, 95% CI 0.26-0.89, p = 0.021) were associated with a decreased risk of bleeding events.

CONCLUSIONS

Hypomethylation of CpGs in the PON1 promoter may be a weak, albeit statistically significant, risk factor of bleeding after dual antiplatelet therapy. Further large-scale studies are needed to verify our results.

Effects of the rs2244613 polymorphism of the CES1 gene on the antiplatelet effect of the receptor P2Y12 blocker clopidogrel

Background The aim of this study was to evaluate the association of the carriage of the rs2244613 polymorphism of the CES1 gene with clopidogrel resistance as well as to evaluate the effectiveness of antiplatelet therapy in the carriers of this marker who have had acute coronary syndrome (ACS). This study also analyzes the procedure of percutaneous coronary intervention and compares the rs2244613 carrier rate between patients with ACS and healthy participants. Methods The study involved 81 patients diagnosed with ACS and 136 conditionally healthy participants. The optical detection of platelet agglutination by VerifyNow was employed to measure residual platelet reactivity in patients with ACS. The rs2244613 polymorphism was determined using real-time polymerase chain reaction. Results According to the results, the AA genotype of the rs2244613 polymorphism of the CES1 gene was detected in 37 patients (45.6%), the CA genotype in 42 patients (51.8%) and the CC genotype in 2 patients (2.6%). The level of residual platelet reactivity in rs2244613 carriers was higher compared with patients who did not have this allelic variant: 183.23 PRU ± 37.24 vs. 154.3 PRU ± 60.36 (p = 0.01). The frequencies of the minor allele C were 28.4% and 28.3% in patients with ACS and healthy participants, respectively. The results of the linear statistical model PRU due to CES1 genotype were as follows: df = 1, F = 6.96, p = 0.01). The standardized beta was 0.285 (p = 0.01) and R2 was 0.081. However, we also added CYP2C19*2 and *17 into the linear regression model. The results of the model were as follows: df = 3, F = 5.1, p = 0.003) and R2 was 0.166. Conclusions We identified a statistically significant correlation between the carriage of the rs2244613 polymorphism of the CES1 gene and the level of residual platelet aggregation among patients with ACS and the procedure of percutaneous coronary intervention.

Association of CYP2C19 Polymorphism with Clopidogrel Resistance in Patients with Acute Coronary Syndrome in China

BACKGROUND The relationship between clopidogrel-resistance (CR) and polymorphism located in genes encoding clopidogrel metabolism-related enzymes has not been fully explored. Thus far, few studies on CR-associated polymorphism have been conducted in the Chinese population. The purpose of this study was to identify CYP2C19 polymorphism associated with CR in patients with acute coronary syndrome in China. MATERIAL AND METHODS There were 125 patients with acute coronary syndromes (ACS) selected for this study. Of these, 27 patients (21.6%) showed CR (less than 10% reduction in platelet accumulation rate), while the remaining 98 patients (78.4%) were non-clopidogrel-resistant (NCR). RESULTS There were significant differences in the allele frequencies of CYP2C19 (rs4244285) (P=0.03) and CYP2C19 (rs4986893) (P=0.005) between the 2 groups; however, there was no significant difference in allele frequencies of ABCB1 (rs1045642) (P=0.661) and PON1 (rs662) (P=0.690) between the 2 groups. The null allele in the CYP2C19 (rs4244285) [odds ratio (OR)=5.317, 95% confidence interval (CI) 1.542-26.428, P=0.001] and CYP2C19 (rs4986893) (OR=4.295, 95%CI 1.312-17.517, P=0.013) is one of the causes of CR in patients with ACS in China. CONCLUSIONS The CYP2C19 polymorphism (rs4244285 and rs4986893) is the correlative factor of CR in patients with ACS in China. It was found that the null allele in the CYP2C19 polymorphism was related to the higher CR risk. According to the key role of CYP2C19 in the clopidogrel activation and the evaluated role of CYP2C19 in this study, further studies should be carried out to formulate therapeutic alternative methods for CR in patients with ACS.

Opportunities and Challenges in Cardiovascular Pharmacogenomics: From Discovery to Implementation

This review will provide an overview of the principles of pharmacogenomics from basic discovery to implementation, encompassing application of tools of contemporary genome science to the field (including areas of apparent divergence from disease-based genomics), a summary of lessons learned from the extensively studied drugs clopidogrel and warfarin, the current status of implementing pharmacogenetic testing in practice, the role of genomics and related tools in the drug development process, and a summary of future opportunities and challenges.