Background Patients with stable coronary artery disease ( CAD ) constitute a heterogeneous group in which the treatment benefits by angiotensin‐converting enzyme ( ACE )‐inhibitor therapy vary between individuals. Our objective was to integrate clinical and pharmacogenetic determinants in an ultimate combined risk prediction model. Methods and Results Clinical, genetic, and outcomes data were used from 8726 stable CAD patients participating in the EUROPA / PERGENE trial of perindopril versus placebo. Multivariable analysis of phenotype data resulted in a clinical risk score (range, 0–21 points). Three single‐nucleotide polymorphisms (rs275651 and rs5182 in the angiotensin‐ II type I‐receptor gene and rs12050217 in the bradykinin type I‐receptor gene) were used to construct a pharmacogenetic risk score ( PGX score; range, 0–6 points). Seven hundred eighty‐five patients (9.0%) experienced the primary endpoint of cardiovascular mortality, nonfatal myocardial infarction or resuscitated cardiac arrest, during 4.2 years of follow‐up. Absolute risk reductions ranged from 1.2% to 7.5% in the 73.5% of patients with PGX score of 0 to 2. As a consequence, estimated annual numbers needed to treat ranged from as low as 29 (clinical risk score ≥10 and PGX score of 0) to 521 (clinical risk score ≤6 and PGX score of 2). Furthermore, our data suggest that long‐term perindopril prescription in patients with a PGX score of 0 to 2 is cost‐effective. Conclusions Both baseline clinical phenotype, as well as genotype determine the efficacy of widely prescribed ACE inhibition in stable CAD . Integration of clinical and pharmacogenetic determinants in a combined risk prediction model demonstrated a very wide range of gradients of absolute treatment benefit.

Summary Hypofibrinolysis is a risk factor for venous and arterial thrombosis, and can be assessed by using a turbidimetric tPA-induced clot lysis time (CLT) assay. Biological variation in clot lysis time may affect the interpretation and usefulness of CLT as a risk factor for thrombosis. Sufficient information about assay variation and biological variation in CLT is not yet available. Thus, this study aimed to determine the analytical, within-subject and between-subject variation in CLT. We collected blood samples from 40 healthy individuals throughout a period of one year (average 11.8 visits) and determined the CLT of each plasma sample in duplicate. The mean (± SD) CLT was 83.8 (± 11.1) minutes. The coefficients of variation for total variation, analytical variation, within-subject variation and between-subject variation were 13.4%, 2.6%, 8.2% and 10.2%, respectively. One measurement can estimate the CLT that does not deviate more than 20% from its true value. The contribution of analytical variation to the within-subject variation was 5.0%, the index of individuality was 0.84 and the reference change value was 23.8%. The CLT was longer in the morning compared to the afternoon and was slightly longer in older individuals (> 40 years) compared to younger (≤40 years) individuals. There was no seasonal variation in CLT and no association with air pollution. CLT correlated weakly with fibrinogen, C-reactive protein, prothrombin time and thrombin generation. This study provides insight into the biological variation of CLT, which can be used in future studies testing CLT as a potential risk factor for thrombosis.

The relevance of P2Y12-receptor gene variation for the outcome of clopidogrel-treated patients undergoing elective coronary stent implantation: A clinical follow-up -

Background Vascular dysfunction in atherosclerosis and diabetes mellitus, as observed in the aging population of developed societies, is associated with vascular DNA damage and cell senescence. We hypothesized that cumulative DNA damage during aging contributes to vascular dysfunction. Methods and Results In mice with genomic instability resulting from the defective nucleotide excision repair genes ERCC1 and XPD ( Ercc1 d/− and Xpd TTD mice), we explored age-dependent vascular function compared with that in wild-type mice. Ercc1 d/− mice showed increased vascular cell senescence, accelerated development of vasodilator dysfunction, increased vascular stiffness, and elevated blood pressure at a very young age. The vasodilator dysfunction was due to decreased endothelial nitric oxide synthase levels and impaired smooth muscle cell function, which involved phosphodiesterase activity. Similar to Ercc1 d/− mice, age-related endothelium-dependent vasodilator dysfunction in Xpd TTD animals was increased. To investigate the implications for human vascular disease, we explored associations between single-nucleotide polymorphisms of selected nucleotide excision repair genes and arterial stiffness within the AortaGen Consortium and found a significant association of a single-nucleotide polymorphism (rs2029298) in the putative promoter region of DDB2 gene with carotid-femoral pulse wave velocity. Conclusions Mice with genomic instability recapitulate age-dependent vascular dysfunction as observed in animal models and in humans but with an accelerated progression compared with wild-type mice. In addition, we found associations between variations in human DNA repair genes and markers for vascular stiffness, which is associated with aging. Our study supports the concept that genomic instability contributes importantly to the development of cardiovascular disease.

Chapter 20 Particles, Coagulation, and Thrombosis Evren Kilinç, Evren Kilinç Department of Internal Medicine, Maastricht University, Maastricht, The NetherlandsSearch for more papers by this authorGoran Rudež, Goran Rudež Department of Hematology, Erasmus University Medical Center, Rotterdam, The NetherlandsSearch for more papers by this authorHenri M. H. Spronk, Henri M. H. Spronk Department of Internal Medicine, Maastricht University, Maastricht, The NetherlandsSearch for more papers by this authorAbderrahim Nemmar, Abderrahim Nemmar Laboratory of Pneumology, Unit for Lung Toxicology, Katholieke Universiteit Leuven, Leuven, BelgiumSearch for more papers by this authorMoniek P. M. de Maat, Moniek P. M. de Maat Department of Hematology, Erasmus University Medical Center, Rotterdam, The NetherlandsSearch for more papers by this authorHugo ten Cate, Hugo ten Cate Department of Internal Medicine, Maastricht University, Maastricht, The NetherlandsSearch for more papers by this authorMarc F. Hoylaerts, Marc F. Hoylaerts Center for Molecular and Vascular Biology, Katholieke Universiteit Leuven, Leuven, BelgiumSearch for more papers by this author Evren Kilinç, Evren Kilinç Department of Internal Medicine, Maastricht University, Maastricht, The NetherlandsSearch for more papers by this authorGoran Rudež, Goran Rudež Department of Hematology, Erasmus University Medical Center, Rotterdam, The NetherlandsSearch for more papers by this authorHenri M. H. Spronk, Henri M. H. Spronk Department of Internal Medicine, Maastricht University, Maastricht, The NetherlandsSearch for more papers by this authorAbderrahim Nemmar, Abderrahim Nemmar Laboratory of Pneumology, Unit for Lung Toxicology, Katholieke Universiteit Leuven, Leuven, BelgiumSearch for more papers by this authorMoniek P. M. de Maat, Moniek P. M. de Maat Department of Hematology, Erasmus University Medical Center, Rotterdam, The NetherlandsSearch for more papers by this authorHugo ten Cate, Hugo ten Cate Department of Internal Medicine, Maastricht University, Maastricht, The NetherlandsSearch for more papers by this authorMarc F. Hoylaerts, Marc F. Hoylaerts Center for Molecular and Vascular Biology, Katholieke Universiteit Leuven, Leuven, BelgiumSearch for more papers by this author Book Editor(s):Flemming R. Cassee, Flemming R. Cassee Center for Environmental Health Research, National Institute for Public Health and the Environment, Bilthoven, The NetherlandsSearch for more papers by this authorNicholas L. Mills, Nicholas L. Mills Queen's Medical Research Institute, Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United KingdomSearch for more papers by this authorDavid Newby, David Newby Queen's Medical Research Institute, University of Edinburgh Centre for Cardiovascular Science, Edinburgh, United KingdomSearch for more papers by this author First published: 14 February 2011 https://doi.org/10.1002/9780470910917.ch20 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Summary This chapter contains sections titled: Introduction Hemostasis Relationship between Coagulation and Inflammation Relationship between PM10 Particles and Hemostasis Relationship between PM2.5 and UFPs and Hemostasis The Relationship between Platelets and Particles Extrapulmonary Translocation of UFPs Effects of Particles on Thrombogenesis and Platelet Activation in Experimental Animal Models Conclusions Acknowledgments References Cardiovascular Effects of Inhaled Ultrafine and Nanosized Particles RelatedInformation

Dual antiplatelet therapy with clopidogrel and aspirin is the cornerstone of treatment for patients with acute coronary syndrome and those who undergo percutaneous coronary intervention (PCI) ([1][1]). Clopidogrel is a thienopyridine that selectively and irreversibly inhibits the ADP receptor P2Y12

SummaryNovel P2Y12 inhibitors are in development to overcome the occurrence of atherothrombotic events associated with poor responsiveness to the widely used P2Y12 inhibitor clopidogrel. Cangrelor is an intravenously administered P2Y12 inhibitor that does not need metabolic conversion to an active metabolite for its antiplatelet action, and as a consequence exhibits a more potent and consistent antiplatelet profile as compared to clopidogrel. It was the objective of this study to determine the contribution of variation in the P2Y12 receptor gene to platelet aggregation after in vitro partial P2Y12 receptor blockade with the direct antagonist cangrelor. Optical aggregometry was performed at baseline and after in vitro addition of 0.05 and 0.25 μM cangrelor to the platelet-rich plasma of 254 healthy subjects. Five haplotype-tagging (ht)-SNPs covering the entire P2Y12 receptor gene were genotyped (rs6798347C>t, rs6787801T>c, rs9859552C>a, rs6801273A>g and rs2046934T>c [T744C]) and haplotypes were inferred. The minor c allele of SNP rs6787801 was associated with a 5% lower 20 μM ADP-induced peak platelet aggregation (0.05 μM cangrelor, p<0.05). Aa homozygotes for SNP rs9859552 showed 20% and 17% less inhibition of platelet aggregation with cangrelor when compared to CC homozygotes (0.05 and 0.25 μM cangrelor respectively; p<0.05). Results of the haplotype analyses were consistent with those of the single SNPs. Polymorphisms of the P2Y12 receptor gene contribute significantly to the interindividual variability in platelet inhibition after partial in vitro blockade with the P2Y12 antagonist cangrelor.

BackgroundAir pollution has consistently been associated with increased morbidity and mortality due to respiratory and cardiovascular disease. Underlying biological mechanisms are not entirely clear, and hemostasis and inflammation are suggested to be involved.ObjectivesOur aim was to study the association of the variation in local concentrations of airborne particulate matter (PM) with aerodynamic diameter < 10 μm, carbon monoxide, nitrogen monoxide, nitrogen dioxide, and ozone with platelet aggregation, thrombin generation, fibrinogen, and C-reactive protein (CRP) levels in healthy individuals.MethodsFrom 40 healthy volunteers, we collected 13 consecutive blood samples within a 1-year period and measured light-transmittance platelet aggregometry, thrombin generation, fibrinogen, and CRP. We performed regression analysis using generalized additive models to study the association between the hemostatic and inflammatory variables, and local environmental concentrations of air pollutants for time lags within 24 hr before blood sampling or 24–96 hr before blood sampling.ResultsIn general, air pollutants were associated with platelet aggregation [average, +8% per interquartile range (IQR), p < 0.01] and thrombin generation (average, +1% per IQR, p < 0.05). Platelet aggregation was not affected by in vitro incubation of plasma with PM. We observed no relationship between any of the air pollutants and fibrinogen or CRP levels.ConclusionsAir pollution increased platelet aggregation as well as coagulation activity but had no clear effect on systemic inflammation. These prothrombotic effects may partly explain the relationship between air pollution and the risk of ischemic cardiovascular disease.

Background— The clinical efficacy of clopidogrel is hampered by a large interindividual variability in platelet inhibition. Polymorphisms in the P2RY12 receptor gene have been suggested to contribute to this variability, but previous studies included a relatively small number of patients and incompletely covered the common variation in the P2RY12 gene. The aim of this study was to comprehensively investigate the possible association between common variation in the entire P2RY12 locus and the magnitude of residual on-clopidogrel platelet reactivity measured by 2 commonly used platelet function assays in a large cohort of patients. Methods and Results— A total of 1031 consecutive patients with coronary artery disease who were scheduled for elective percutaneous coronary interventions were enrolled. Platelet function was assessed by means of ADP-induced light-transmittance aggregometry and the VerifyNow P2Y12 assay. Six haplotype-tagging single nucleotide polymorphisms were carefully selected to comprehensively cover the total common variation in the P2RY12 gene and its flanking regulatory regions. Six common haplotypes were inferred from these haplotype-tagging single nucleotide polymorphisms (denoted A to F). Haplotype F was associated with significantly lower residual on-clopidogrel platelet reactivity compared with the reference haplotype A. The size of this effect per haplotype allele was approximately 5% aggregation in the ADP-induced light-transmittance aggregometry (P<0.05) and 11 P2Y12 reaction units in the VerifyNow P2Y12 assay (P<0.05). Conclusions— Common variation in the P2RY12 gene is a significant determinant of the interindividual variability in residual on-clopidogrel platelet reactivity in patients with coronary artery disease.

The platelet receptor P2Y12 (gene symbol P2RY12) is involved in several processes that contribute to restenosis after percutaneous coronary interventions (PCI). Therefore, common variation in the P2Y12 gene may serve as a useful marker for risk stratification. We studied whether common variation in the platelet receptor P2Y12 gene affects the risk of restenosis after PCI. Comprehensive coverage of common variation in the P2Y12 gene was obtained by genotyping five haplotype-tagging SNPs (ht-SNPs) in 2,062 PCI-treated patients who received a stent and participated in the GENetic DEterminants of Restenosis (GENDER) Study. Haplotypes were inferred and their association with target vessel revascularization (TVR) was studied. Seven P2Y12 haplotypes were identified with an allelic frequency above 5% (designated here H1 to H7) of which two (H5 and H7) were associated with a higher risk of TVR (hazard ratios [HR]=1.4, 95% confidence interval [CI]=1.0-2.0; and HR=1.6, 95% CI=1.2-2.0, respectively) than the reference P2Y12 haplotype (H1), which contains the common alleles of all five P2Y12 ht-SNPs. Our study shows that common variation in the P2Y12 gene predicts restenosis in PCI-treated patients.