Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 23
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Catheter Cardiovasc Interv ; 96(3): 609-613, 2020 09 01.
Article in English | MEDLINE | ID: mdl-31868293

ABSTRACT

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is a technically challenging procedure. In failed cases, plaque modification strategy (also known as "investment procedure"), defined as the intentional dilation of the subintimal space through the CTO segment, can be applied. The typical dilation device used in this strategy is a regular angioplasty balloon (either semi- or noncompliant). Performing this technique with a drug-coated balloon (DCB) may facilitate a staged procedure by promoting a better vessel healing. Herein, we present three cases of failed CTO PCI, managed with DCB plaque modification, and their follow-up staged procedure.


Subject(s)
Angioplasty, Balloon, Coronary/instrumentation , Cardiac Catheters , Cardiovascular Agents/administration & dosage , Coronary Occlusion/therapy , Paclitaxel/administration & dosage , Percutaneous Coronary Intervention/adverse effects , Aged , Chronic Disease , Coated Materials, Biocompatible , Coronary Occlusion/diagnostic imaging , Female , Humans , Male , Middle Aged , Stents , Treatment Failure
2.
Circ Res ; 118(2): 230-40, 2016 Jan 22.
Article in English | MEDLINE | ID: mdl-26596284

ABSTRACT

RATIONALE: Genetic variation at the chromosome 9p21 cardiovascular risk locus has been associated with peripheral artery disease, but its mechanism remains unknown. OBJECTIVE: To determine whether this association is secondary to an increase in atherosclerosis, or it is the result of a separate angiogenesis-related mechanism. METHODS AND RESULTS: Quantitative evaluation of human vascular samples revealed that carriers of the 9p21 risk allele possess a significantly higher burden of immature intraplaque microvessels than carriers of the ancestral allele, irrespective of lesion size or patient comorbidity. To determine whether aberrant angiogenesis also occurs under nonatherosclerotic conditions, we performed femoral artery ligation surgery in mice lacking the 9p21 candidate gene, Cdkn2b. These animals developed advanced hindlimb ischemia and digital autoamputation, secondary to a defect in the capacity of the Cdkn2b-deficient smooth muscle cell to support the developing neovessel. Microarray studies identified impaired transforming growth factor ß (TGFß) signaling in cultured cyclin-dependent kinase inhibitor 2B (CDKN2B)-deficient cells, as well as TGFß1 upregulation in the vasculature of 9p21 risk allele carriers. Molecular signaling studies indicated that loss of CDKN2B impairs the expression of the inhibitory factor, SMAD-7, which promotes downstream TGFß activation. Ultimately, this manifests in the upregulation of a poorly studied effector molecule, TGFß1-induced-1, which is a TGFß-rheostat known to have antagonistic effects on the endothelial cell and smooth muscle cell. Dual knockdown studies confirmed the reversibility of the proposed mechanism, in vitro. CONCLUSIONS: These results suggest that loss of CDKN2B may not only promote cardiovascular disease through the development of atherosclerosis but may also impair TGFß signaling and hypoxic neovessel maturation.


Subject(s)
Atherosclerosis/enzymology , Cyclin-Dependent Kinase Inhibitor p15/metabolism , Muscle, Skeletal/blood supply , Muscle, Smooth, Vascular/enzymology , Myocytes, Smooth Muscle/enzymology , Neovascularization, Physiologic , Signal Transduction , Transforming Growth Factor beta1/metabolism , Animals , Atherosclerosis/genetics , Atherosclerosis/mortality , Atherosclerosis/pathology , Carotid Arteries/enzymology , Carotid Arteries/pathology , Cell Hypoxia , Cells, Cultured , Chromosomes, Human, Pair 9 , Coronary Vessels/enzymology , Coronary Vessels/pathology , Cyclin-Dependent Kinase Inhibitor p15/deficiency , Cyclin-Dependent Kinase Inhibitor p15/genetics , Disease Models, Animal , Female , Genetic Predisposition to Disease , Hindlimb , Humans , Male , Mice, Inbred C57BL , Mice, Knockout , Muscle, Smooth, Vascular/physiopathology , Neovascularization, Pathologic , Phenotype , RNA Interference , Smad7 Protein/metabolism , Time Factors , Transfection , Transforming Growth Factor beta1/genetics
3.
Curr Cardiol Rep ; 16(5): 479, 2014 May.
Article in English | MEDLINE | ID: mdl-24691635

ABSTRACT

Genome-wide association studies for coronary artery disease utilizing the case control association study approach has identified 50 genetic risk variants associated with coronary artery disease or myocardial infarction. All of these genetic variants are of genome wide significance and replicated in an independent population. It is of note that 35 of these 50 genetic risk variants act through mechanisms as yet unknown. These findings have great implications for the pathogenesis of atherosclerosis, as well as new targets for the development of novel therapies for the prevention and treatment of CAD. The genetic variant PCSK9 has already led to the development of a monoclonal anti-body which is undergoing assessment in phases I, II, and III clinical trials. This therapy shows very promising results and since it increases removal of LDL-C, it is complementary to current statin therapy. Assessing the beneficial or deleterious effects of a lifelong exposure to a genetic risk variant (Mendelian randomization) will be an important adjunct to clinical trials.


Subject(s)
Coronary Artery Disease/genetics , Myocardial Infarction/genetics , Polymorphism, Single Nucleotide , Coronary Artery Disease/physiopathology , Female , Genetic Predisposition to Disease , Genetic Variation , Genome-Wide Association Study , Humans , Male , Predictive Value of Tests , Reproducibility of Results , Risk Factors
4.
Hum Genet ; 127(1): 101-5, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19885677

ABSTRACT

The transcription factor GATA2 was reported to associate with coronary artery disease (CAD) in the family-based Genecard sample (Connelly et al. in PLoS Genet 2:e139, 2006). We asked whether GATA2 associates with sporadic cases of CAD in the Ottawa Heart Genomics Study (OHGS) and Cleveland Clinic (CC) populations. We genotyped the lead single nucleotide polymorphism (SNP) from Genecard, rs2713604 which is located in intron 5-6 of GATA2 in 600 CAD cases and 625 controls, as well as a tag SNP rs1573949 (r (2) = 0.87 in Caucasians of European ancestry in Utah from HapMap) in 1,136 cases and 1,162 controls in the OHGS1 population. A further 1,838 CAD cases and 913 controls derived from an independent sample combining genotypes from CC and OHGS2 populations were genotyped for rs1573949. Neither of the genotyped SNPs associates with CAD in the OHGS1 or CC/OHGS2 populations. Our data suggest that GATA2 does not contribute to the development of angiographic CAD among sporadic cases.


Subject(s)
Coronary Artery Disease/genetics , GATA2 Transcription Factor/genetics , Polymorphism, Single Nucleotide , Adult , Aged , Canada , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Female , Gene Frequency , Genotype , Humans , Male , Middle Aged , Odds Ratio , Ohio
5.
JACC Cardiovasc Interv ; 13(21): 2560-2570, 2020 11 09.
Article in English | MEDLINE | ID: mdl-33153569

ABSTRACT

OBJECTIVES: The aim of this study was to define the optimal fluoroscopic viewing angles of both coronary ostia and important coronary bifurcations by using 3-dimensional multislice computed tomographic data. BACKGROUND: Optimal fluoroscopic projections are crucial for coronary imaging and interventions. Historically, coronary fluoroscopic viewing angles were derived empirically from experienced operators. METHODS: In this analysis, 100 consecutive patients who underwent computed tomographic coronary angiography (CTCA) for suspected coronary artery disease were studied. A CTCA-based method is described to define optimal viewing angles of both coronary ostia and important coronary bifurcations to guide percutaneous coronary interventions. RESULTS: The average optimal viewing angle for ostial left main stenting was left anterior oblique (LAO) 37°, cranial (CRA) 22° (95% confidence interval [CI]: LAO 33° to 40°, CRA 19° to 25°) and for ostial right coronary stenting was LAO 79°, CRA 41° (95% CI: LAO 74° to 84°, CRA 37° to 45°). Estimated mean optimal viewing angles for bifurcation stenting were as follows: left main: LAO 0°, caudal (CAU) 49° (95% CI: right anterior oblique [RAO] 8° to LAO 8°, CAU 43° to 54°); left anterior descending with first diagonal branch: LAO 11°, CRA 71° (95% CI: RAO 6° to LAO 27°, CRA 66° to 77°); left circumflex bifurcation with first marginal branch: LAO 24°, CAU 33° (95% CI: LAO 15° to 33°, CAU 25° to 41°); and posterior descending artery and posterolateral branch: LAO 44°, CRA 34° (95% CI: LAO 35° to 52°, CRA 27° to 41°). CONCLUSIONS: CTCA can suggest optimal fluoroscopic viewing angles of coronary artery ostia and bifurcations. As the frequency of use of diagnostic CTCA increases in the future, it has the potential to provide additional information for planning and guiding percutaneous coronary intervention procedures.


Subject(s)
Computed Tomography Angiography , Multidetector Computed Tomography , Coronary Angiography , Fluoroscopy , Humans , Treatment Outcome
6.
Curr Atheroscler Rep ; 11(3): 175-81, 2009 May.
Article in English | MEDLINE | ID: mdl-19361348

ABSTRACT

Coronary artery disease (CAD) and its sequelae represent a significant health burden. Over the past two decades, numerous studies have attempted to link DNA sequence variation with the risk of CAD and related phenotypes. There has been significant evolution in technology from the early linkage studies within kindreds, and now we are able to use high-density genotyping to facilitate large-scale genome-wide association studies. The first novel genetic risk factor for CAD, 9p21.3, has been confirmed, and other loci are awaiting replication studies. The relative importance of each locus from a global standpoint and the incremental information conferred by testing for genetic variants remain to be determined.


Subject(s)
Coronary Artery Disease/genetics , Genotype , Phenotype , Chromosome Mapping , Humans , Risk Factors
7.
Curr Cardiol Rep ; 11(4): 282-7, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19563728

ABSTRACT

The manifestations of coronary artery disease are varied. They all arise as a consequence of the deposition of atherosclerotic plaque within the vessel wall. The most feared sequela of coronary artery disease is sudden and unexpected death in the ostensibly healthy patient. Plaque rupture of hemodynamically insignificant atherosclerotic plaques and ensuing thrombosis is likely responsible for a large proportion of such deaths. Identifying populations at increased risk for sudden death would represent a major advance. Such screening is contingent upon identification of DNA sequence variants that predispose individuals to plaque rupture. Phenotyping is not sufficiently nuanced to detect such variants on a large scale, so we are limited to end points that are crude surrogates for plaque rupture. As imaging modalities are refined and our ability to recruit large numbers of appropriate patients is facilitated by the formation of alliances, our ability to probe this conundrum via a genome-wide approach will improve.


Subject(s)
Coronary Artery Disease/genetics , Acyl Coenzyme A/antagonists & inhibitors , Acyl Coenzyme A/genetics , Carotid Stenosis/genetics , Coronary Artery Disease/drug therapy , Coronary Artery Disease/prevention & control , Cytochrome P-450 Enzyme System , Death, Sudden, Cardiac/prevention & control , Humans , Platelet Aggregation Inhibitors/pharmacology , Polymorphism, Genetic , Risk Factors
8.
Can J Cardiol ; 33(12): 1668-1674, 2017 12.
Article in English | MEDLINE | ID: mdl-29066329

ABSTRACT

BACKGROUND: Data on the impact of coronary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) on quality of life (QOL) are limited. To date, studies have been limited in sample size and have focused on only a few domains of the Seattle Angina Questionnaire (SAQ). We evaluated the relationship between coronary CTO PCI and QOL in patients with symptoms of angina, incorporating all aspects of the SAQ. METHODS: The SAQ was used to interrogate patients at baseline and at 12 months after CTO PCI. The primary end point was improvement in SAQ scores. RESULTS: A total of 184 patients answered the baseline SAQ. One hundred twenty-two patients answered both questionnaires. SAQ responders were more likely to be men, more like to be in stable medical condition, and more likely to have undergone a successful procedure. We observed statistically significant improvement (P < 0.0001) in physical limitation (mean difference [MD], +27; 95% confidence interval [CI], +23 to +32), angina stability (MD, +16; 95% CI, +10 to +21), angina frequency (MD, +27; 95% CI, +22 to +32), treatment satisfaction (MD, +10; 95% CI, +6 to +13), and QOL domains (MD, +28; 95% CI, +24 to +32). Patients with coronary artery bypass grafting, dissection re-entry techniques, and high complexity (Japanese CTO [J-CTO] ≥ 3) had a similar degree of improvement when compared with their counterparts. CONCLUSIONS: CTO PCI is associated with a significant improvement in QOL at 12 months. Patients with complex CTOs derive benefits similar to those in patients with less complex CTOs.


Subject(s)
Angina Pectoris/psychology , Coronary Occlusion/surgery , Percutaneous Coronary Intervention/adverse effects , Postoperative Complications , Quality of Life , Aged , Angina Pectoris/etiology , Chronic Disease , Female , Follow-Up Studies , Humans , Male , Surveys and Questionnaires , Time Factors
9.
Article in English | MEDLINE | ID: mdl-24932357

ABSTRACT

The emergence of personalized medicine mandates a complete understating of DNA sequence variation that modulates drug response. Initial forays have been made in the cardiac arena, yet much remains to be elucidated in the pharmacogenetics of cardiac drugs. Most progress has been made in describing DNA sequence variation related to the anticoagulant warfarin and the antiplatelet drug clopidogrel. This includes a description of DNA sequence variation that underlies pharmacokinetic and pharmacodynamic variability, the impact of such variation on predicting hard outcomes, and the ability of genotype-guided prescription to facilitate rapid titration to a therapeutic range while avoiding unnecessary high plasma levels. Nuanced prescription will require a complete inventory of DNA sequence variants that underlie drug-related side effects.


Subject(s)
Cardiovascular Agents/therapeutic use , Cardiovascular Diseases/drug therapy , Cardiovascular Diseases/genetics , Gene Expression Regulation/drug effects , Pharmacogenetics , Precision Medicine , Animals , Biotransformation , Cardiovascular Agents/adverse effects , Cardiovascular Agents/pharmacokinetics , Drug Interactions , Genotype , Humans , Phenotype , Risk Assessment , Risk Factors , Treatment Outcome
10.
PLoS One ; 9(9): e106294, 2014.
Article in English | MEDLINE | ID: mdl-25180781

ABSTRACT

OBJECTIVE: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a circulating protein that promotes degradation of the low density lipoprotein (LDL) receptor. Mutations that block PCSK9 secretion reduce LDL-cholesterol and the incidence of myocardial infarction (MI). However, it remains unclear whether elevated plasma PCSK9 associates with coronary atherosclerosis (CAD) or more directly with rupture of the plaque causing MI. METHODS AND RESULTS: Plasma PCSK9 was measured by ELISA in 645 angiographically defined controls (<30% coronary stenosis) and 3,273 cases of CAD (>50% stenosis in a major coronary artery) from the Ottawa Heart Genomics Study. Because lipid lowering medications elevated plasma PCSK9, confounding association with disease, only individuals not taking a lipid lowering medication were considered (279 controls and 492 with CAD). Replication was sought in 357 controls and 465 with CAD from the Emory Cardiology Biobank study. PCSK9 levels were not associated with CAD in Ottawa, but were elevated with CAD in Emory. Plasma PCSK9 levels were elevated in 45 cases with acute MI (363.5±140.0 ng/ml) compared to 398 CAD cases without MI (302.0±91.3 ng/ml, p = 0.004) in Ottawa. This finding was replicated in the Emory study in 74 cases of acute MI (445.0±171.7 ng/ml) compared to 273 CAD cases without MI (369.9±139.1 ng/ml, p = 3.7×10(-4)). Since PCSK9 levels were similar in CAD patients with or without a prior (non-acute) MI, our finding suggests that plasma PCSK9 is elevated either immediately prior to or at the time of MI. CONCLUSION: Plasma PCSK9 levels are increased with acute MI.


Subject(s)
Coronary Angiography , Myocardial Infarction/blood , Proprotein Convertases/blood , Serine Endopeptidases/blood , Biological Specimen Banks , Canada , Case-Control Studies , Coronary Artery Disease/blood , Female , Genomics , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Linear Models , Logistic Models , Male , Middle Aged , Myocardial Infarction/drug therapy , Proprotein Convertase 9 , Retrospective Studies
11.
J Am Coll Cardiol ; 61(20): 2029-37, 2013 May 21.
Article in English | MEDLINE | ID: mdl-23524054

ABSTRACT

A paradigm shift toward biology occurred in the 1990s and was subsequently catalyzed by the sequencing of the human genome in 2000. The cost of deoxyribonucleic acid (DNA) sequencing has gone from millions to thousands of dollars with sequencing of one's entire genome costing only $1,000. Rapid DNA sequencing is being embraced for single gene disorders, particularly for sporadic cases and those from small families. Transmission of lethal genes such as associated with Huntington's disease can, through in vitro fertilization, avoid passing it on to one's offspring. DNA sequencing will meet the challenge of elucidating the genetic predisposition for common polygenic diseases, especially in determining the function of the novel common genetic risk variants and identifying the rare variants, which may also partially ascertain the source of the missing heritability. The challenge for DNA sequencing remains great, despite human genome sequences being 99.5% identical, the 3 million single nucleotide polymorphisms responsible for most of the unique features add up to 40 to 60 new mutations per person which, for 7 billion people, is 300 to 400 billion mutations. It is claimed that DNA sequencing has increased 10,000-fold while information storage and retrieval only 16-fold. The physician and health user will be challenged by the convergence of 2 major trends, whole genome sequencing, and the storage/retrieval and integration of the data.


Subject(s)
Cardiovascular Diseases/genetics , Genetic Techniques , Genome, Human , Genomics , Precision Medicine , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/therapy , Humans
12.
Circ Cardiovasc Genet ; 6(4): 372-80, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23729007

ABSTRACT

BACKGROUND: Variants at the 9p21 locus associate with the risk of coronary artery disease (CAD) or myocardial infarction (MI). However, atherosclerotic plaque deposition is distinct from MI (plaque rupture and thrombosis), and recent studies showed no association between these variants and MI in patients with preexisting CAD. We performed haplotype analysis at the 9p21 locus to test whether haplotypes at distinct linkage disequilibrium blocks predict these phenotypes. METHODS AND RESULTS: Using 24 single-nucleotide polymorphisms genotyped in white patients without diabetes mellitus, we reconstructed haplotypes at the 9p21 locus. Patients with angiograhic CAD/MI had ≥1 epicardial stenosis >50% (n=2352), whereas controls were asymptomatic and over the age of 60 years (n=2116). For CAD patients, regression models examined the association of haplotypes with initial age of symptomatic CAD, number of diseased vessels, and history of MI. In the case-control study, only haplotypes at 1 block tagged by rs1333049 associated with CAD more so than MI. These haplotypes also associated with early onset of CAD (ß=-0.13; P=1.37×10(-4)) and disease severity (ß=0.1823; P=0.006) but not with prevalent MI among patients with CAD. In contrast, haplotypes at another block tagged by rs518394 associated with prevalent MI (ß=0.239; P=2.05×10(-4)), but remarkably these are inversely associated with disease severity (ß=-0.196; P=0.003). This MI association was replicated in the Cleveland Clinic GeneBank premature CAD cohort (n=1385; ß=0.207; P=0.019). CONCLUSIONS: Variants/haplotypes at 2 blocks are distinguished at 9p21; those at 1 block predispose to atherosclerosis, whereas those at the other predispose to MI among patients with preexisting CAD.


Subject(s)
Chromosomes, Human, Pair 9 , Coronary Artery Disease/genetics , Myocardial Infarction/genetics , Age Factors , Aged , Aged, 80 and over , Case-Control Studies , Coronary Artery Disease/diagnostic imaging , Female , Genetic Loci , Genotype , Haplotypes , Humans , Linkage Disequilibrium , Male , Middle Aged , Myocardial Infarction/diagnostic imaging , Phenotype , Polymorphism, Single Nucleotide , Radiography , Risk Factors
13.
Can J Cardiol ; 28(6): 693-9, 2012.
Article in English | MEDLINE | ID: mdl-23036280

ABSTRACT

Personalized medicine is the tailoring of the diagnosis, prevention, and treatment to the characteristics of each individual patient. In this review, we provide a status report on genetic variants that influence therapy with antiplatelet agents, warfarin, and statins. Resistance to clopidogrel, an antiplatelet therapy, has been shown to be present in 25% to 30% of Caucasians and an even higher percentage in Asians. Part of this resistance is because of the CYP2C19*2 allele. Administering clopidogrel on the basis of previous genetic testing remains controversial. A recent breakthrough in point-of-care genetic testing for clopidogrel might be significant, not only for genetic testing for clopidogrel, but for the whole of personalized medicine. Genetic testing for aspirin resistance is not yet recommended because of incomplete genetic data. Studies to determine the value of genetic testing before the administration of warfarin are ongoing. Testing for SLCO1B1 allele for individuals with muscle cramps who are taking statins could be very helpful but is not yet recommended as routine. Pharmacogenetics has the potential to customize therapy and move away from the current model of 1 drug fits all.


Subject(s)
Cardiovascular Agents/therapeutic use , Cardiovascular Diseases/genetics , Cardiovascular Diseases/therapy , Disease Management , Genetic Therapy/methods , Precision Medicine/trends , Humans
14.
Med Clin North Am ; 96(1): 113-22, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22391256

ABSTRACT

The next decade will focus on identifying the missing heritability of coronary artery disease (CAD). This process will involve a more comprehensive interrogation of common single nucleotide polymorphisms (SNPs) that impart modest biologic effect and an interrogation of rare SNPs that impart profound biologic effect. In parallel, an investigation of the underlying biology of the described association will likely yield novel pathways that provide therapeutic targets. Once we obtain a more complete inventory of sequence variation that predisposes to CAD, a more realistic assessment of the role of genetic risk scoring allied with standard risk algorithms will be possible.


Subject(s)
Coronary Artery Disease , Genetic Predisposition to Disease , Genomics , Inheritance Patterns , Pharmacogenetics , Biomarkers , Computational Biology/methods , Computational Biology/trends , Coronary Artery Disease/epidemiology , Coronary Artery Disease/genetics , Forecasting , Genomics/methods , Genomics/trends , Human Genome Project , Humans , Pharmacogenetics/methods , Pharmacogenetics/trends , Polymorphism, Single Nucleotide , Risk Factors
15.
Circ Cardiovasc Genet ; 5(2): 217-25, 2012 Apr 01.
Article in English | MEDLINE | ID: mdl-22319020

ABSTRACT

BACKGROUND: Recent genome-wide association studies (GWAS) have identified several novel loci that reproducibly associate with coronary artery disease (CAD) and/or myocardial infarction risk. However, known common CAD risk variants explain only 10% of the predicted genetic heritability of the disease, suggesting that important genetic signals remain to be discovered. METHODS AND RESULTS: We performed a discovery meta-analysis of 5 GWAS involving 13 949 subjects (7123 cases, 6826 control subjects) imputed at approximately 5 million single nucleotide polymorphisms, using pilot 1000 Genomes-based haplotypes. Promising loci were followed up in an additional 5 studies with 11 032 subjects (5211 cases, 5821 control subjects). A novel CAD locus on chromosome 6p21.3 in the major histocompatibility complex (MHC) between HCG27 and HLA-C was identified and achieved genome-wide significance in the combined analysis (rs3869109; p(discovery)=3.3×10(-7), p(replication)=5.3×10(-4)p(combined)=1.12×10(-9)). A subanalysis combining discovery GWAS showed an attenuation of significance when stringent corrections for European population structure were used (P=4.1×10(-10) versus 3.2×10(-7)), suggesting that the observed signal is partly confounded due to population stratification. This gene dense region plays an important role in inflammation, immunity, and self-cell recognition. To determine whether the underlying association was driven by MHC class I alleles, we statistically imputed common HLA alleles into the discovery subjects; however, no single common HLA type contributed significantly or fully explained the observed association. CONCLUSIONS: We have identified a novel locus in the MHC associated with CAD. MHC genes regulate inflammation and T-cell responses that contribute importantly to the initiation and propagation of atherosclerosis. Further laboratory studies will be required to understand the biological basis of this association and identify the causative allele(s).


Subject(s)
Coronary Artery Disease/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Histocompatibility Antigens Class I/genetics , Adult , Aged , Alleles , Female , Genotype , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Risk Factors , White People/genetics
16.
J Clin Endocrinol Metab ; 96(6): 1783-8, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21411544

ABSTRACT

OBJECTIVE: Our objective was to determine whether peripheral blood mononuclear cells express amyloid precursor protein (APP) and other mediators involved in the pathogenesis of Alzheimer's disease and whether their expression is suppressed by insulin. RESEARCH DESIGN AND METHODS: Ten obese type 2 diabetic patients were infused with insulin (2 U/h with 100 ml 5% dextrose/h) for 4 h. Patients were also infused with 5% dextrose/h or normal physiological saline for 4 h, respectively, on two other days as controls. Blood samples were obtained at 0, 2, 4, and 6 h. RESULTS: Insulin infusion significantly suppressed the expression of APP, presenilin-1, presenilin-2, and glycogen synthase kinase-3ß in peripheral blood mononuclear cells. Dextrose and saline infusions did not alter these indices. Insulin infusion also caused significant parallel reductions in nuclear factor-κB binding activity and plasma concentrations of serum amyloid A and intercellular adhesion molecule-1. CONCLUSIONS: A low dose infusion of insulin suppresses APP, presenilin-1, presenilin-2, and glycogen synthase kinase-3ß, key proteins involved in the pathogenesis of Alzheimer's disease, in parallel with exerting its other antiinflammatory effects.


Subject(s)
Amyloid beta-Protein Precursor/metabolism , Glycogen Synthase Kinase 3/metabolism , Insulin/pharmacology , Leukocytes, Mononuclear/metabolism , Presenilins/metabolism , Adult , Amyloid beta-Protein Precursor/genetics , Analysis of Variance , Blood Glucose , Blotting, Western , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Female , Glycogen Synthase Kinase 3/genetics , Glycogen Synthase Kinase 3 beta , Humans , Insulin/blood , Leukocytes, Mononuclear/drug effects , Male , Middle Aged , Obesity/genetics , Obesity/metabolism , Presenilins/genetics , Reverse Transcriptase Polymerase Chain Reaction , Time Factors
17.
Can J Cardiol ; 26 Suppl A: 56A-59A, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20386763

ABSTRACT

The past three years has seen the completion of a series of genome-wide association studies designed to identify genetic variants associated with risk for coronary artery disease (CAD) or its related phenotype, myocardial infarction (MI). The first and most robust genetic risk variant is located on chromosome 9p21.3. A series of other loci, with less prevalence and smaller population-attributable risks, were described to associate with CAD/MI. However, these loci explain only a fraction of the heritable component of CAD/MI. A small fraction of these loci alter the function of genes known to be involved in atherogenesis and/or thrombosis. The rest do not appear to impart their risk via any known risk factors, implying yet unknown pathogenetic pathways. Moreover, many loci, including 9p21, are located in intergenic segments and elicit the phenotype by novel mechanisms whose elucidation will most likely unravel novel therapeutic targets. Future investigation will be focused on defining the underlying mechanism by which the phenotype is affected, the role of these genetic markers in standard risk prediction models and identification of further loci to explain the 'missing heritability'.


Subject(s)
Coronary Artery Disease/genetics , Genomics , Genetic Markers , Humans , Phenotype , Risk Factors
18.
J Cardiovasc Transl Res ; 3(3): 173-82, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20560037

ABSTRACT

This review covers the advances made in the last decade utilizing the high-density single-nucleotide microarrays to screen the entire human genome for genetic risk variants and outlines future strategies to draw deeper into the human genetic front. The sequence of the human genome provides the blueprint for life, while its variation provides the spice of life. Approximately 99.5% of the human genome DNA sequence is identical among humans with 0.5% of the genome sequence (15 million bps) accounting for all individual differences including susceptibility for disease. The new technology of the computerized chip array containing up to millions of SNPs as DNA markers makes possible genome-wide association studies to detect genetic predisposition to common polygenic disorders such as coronary artery disease (CAD). The sample sizes required for these studies are massive and large; worldwide consortiums such as CARDIoGRAM have been formed to accommodate this requirement. The progress has been remarkable with the identification of 9p21 followed by several others within the past 2 years. It is expected that most of the common variants (minor allele frequency, MAF >5%) will be identified for CAD within the next 2 to 3 years. Rare variants (MAF <5%) will require direct sequencing which will be delayed somewhat. The ultimate objective for the future is the sequencing and functional analysis of the causative polymorphisms. This will require a new approach involving several disciplines, namely, bioinformatics, high-throughput cell expression, and animal models.


Subject(s)
Coronary Artery Disease/genetics , Genome-Wide Association Study , Polymorphism, Single Nucleotide , Animals , Chromosomes, Human, Pair 9 , Databases, Genetic , Gene Expression Profiling/methods , Gene Frequency , Genetic Predisposition to Disease , Humans , Meta-Analysis as Topic , Multifactorial Inheritance , Oligonucleotide Array Sequence Analysis , Phenotype , Risk Assessment , Risk Factors , Sample Size
19.
J Am Coll Cardiol ; 56(6): 479-86, 2010 Aug 03.
Article in English | MEDLINE | ID: mdl-20670758

ABSTRACT

OBJECTIVES: The purpose of this study was to test the hypothesis that 9p21 gene dosage determines the severity of coronary artery disease (CAD). BACKGROUND: The 9p21 locus is the first common genetic variant to associate with risk of CAD and/or myocardial infarction in multiple studies. METHODS: A cross-sectional study examined nondiabetic patients with CAD defined by coronary angiography to have at least 1 epicardial stenosis >50%. In all, 950 patients with early onset CAD (age 56.1 +/- 9.6 years) and an independent sample of 764 patients with late onset CAD (age 70.0 +/- 8.0 years) were enrolled from the cardiac catheterization laboratories at the University of Ottawa Heart Institute from April 15, 2006, to August 15, 2008, and genotyped for the single nucleotide polymorphism rs1333049 9p21 risk variant. Angiographers were blinded to genotype. The association between 9p21 risk genotype and the proportion of patients with 3-vessel disease, 1-vessel disease, left main trunk disease, and coronary artery bypass graft surgery was tested, as was its association with the modified Gensini and Duke coronary scoring indexes. RESULTS: Among younger CAD cases, 3-vessel disease demonstrated a strong, direct association with 9p21 gene dosage (p = 4.26 x 10(-4)). Conversely, 1-vessel disease demonstrated a strong inverse association with increasing gene dosage (p = 2.41 x 10(-5)). In the replication sample, gene dosage also predicted 3-vessel disease (p = 6.51 x 10(-6)). Left main trunk disease and coronary artery bypass graft surgery demonstrated a direct strong association with gene dosage (p = 3.66 x 10(-4)) and (p = 2.42 x 10(-2)), respectively. Gene dosage demonstrated a strong, direct association with both the modified Gensini (p < 0.0001) and modified Duke (p = 3 x 10(-4)) coronary scores. Risk variant 9p21 did not associate with myocardial infarction once stratified for disease severity. CONCLUSIONS: Gene dosage of the common risk variant 9p21 predicts the severity of coronary atheromatous burden.


Subject(s)
Chromosomes, Human, Pair 9/genetics , Coronary Artery Disease/genetics , Gene Dosage , Genetic Predisposition to Disease/epidemiology , Risk Assessment/methods , Severity of Illness Index , Age Factors , Age of Onset , Aged , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/epidemiology , Cross-Sectional Studies , Electrocardiography , Female , Follow-Up Studies , Genetic Variation , Genotype , Humans , Male , Middle Aged , Ontario/epidemiology , Prevalence , Retrospective Studies , Risk Factors
20.
Circ Cardiovasc Genet ; 3(5): 468-74, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20729558

ABSTRACT

BACKGROUND: Genome-wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) at multiple loci that are significantly associated with coronary artery disease (CAD) risk. In this study, we sought to determine and compare the predictive capabilities of 9p21.3 alone and a panel of SNPs identified and replicated through GWAS for CAD. METHODS AND RESULTS: We used the Ottawa Heart Genomics Study (OHGS) (3323 cases, 2319 control subjects) and the Wellcome Trust Case Control Consortium (WTCCC) (1926 cases, 2938 control subjects) data sets. We compared the ability of allele counting, logistic regression, and support vector machines. Two sets of SNPs, 9p21.3 alone and a set of 12 SNPs identified by GWAS and through a model-fitting procedure, were considered. Performance was assessed by measuring area under the curve (AUC) for OHGS using 10-fold cross-validation and WTCCC as a replication set. AUC for logistic regression using OHGS increased significantly from 0.555 to 0.608 (P=3.59×10⁻¹4) for 9p21.3 versus the 12 SNPs, respectively. This difference remained when traditional risk factors were considered in a subgroup of OHGS (1388 cases, 2038 control subjects), with AUC increasing from 0.804 to 0.809 (P=0.037). The added predictive value over and above the traditional risk factors was not significant for 9p21.3 (AUC 0.801 versus 0.804, P=0.097) but was for the 12 SNPs (AUC 0.801 versus 0.809, P=0.0073). Performance was similar between OHGS and WTCCC. Logistic regression outperformed both support vector machines and allele counting. CONCLUSIONS: Using the collective of 12 SNPs confers significantly greater predictive capabilities for CAD than 9p21.3, whether traditional risks are or are not considered. More accurate models probably will evolve as additional CAD-associated SNPs are identified.


Subject(s)
Cardiovascular Diseases/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Polymorphism, Single Nucleotide , Adult , Algorithms , Genotype , Humans , Middle Aged , Predictive Value of Tests , Risk Factors
SELECTION OF CITATIONS
SEARCH DETAIL