Decreased factor XIII levels in factor XIII A subunit Leu34 homozygous patients with coronary artery disease

INTRODUCTION: The effect of factor XIII A subunit (FXIII-A) Val34Leu polymorphism on the risk of coronary artery disease (CAD) has been extensively studied. In this study we investigated how FXIII-A Val34Leu genotypes influence plasma factor XIII levels in patients with coronary sclerosis (CS) and myocardial infarction (MI) and how fibrinogen level modulates this effect. PATIENTS AND METHODS: 955 consecutive patients admitted for coronary angiography were categorized according to the presence or absence of significant CS and the history of MI. The frequency of FXIII-A Val34Leu polymorphism, fibrinogen, FXIII activity and antigen levels were determined. RESULTS AND CONCLUSIONS: CS or MI decreased FXIII levels in patients homozygous for FXIII-A Leu34 allele, but not in heterozygous or wild type patients. In the subgroup of patients with CS, but without the history of MI no significant effect was detected, which suggests that MI has a more prominent role. The specific activity of plasma FXIII was independent of FXIII-A Val34Leu genotype. FXIII and fibrinogen levels significantly correlated in CS+ and MI+ patients. In MI+ patients of Leu/Val or Leu/Leu genotypes and with fibrinogen levels in the lowest quartile, FXIII levels were lower than in the same patient groups, but with higher fibrinogen level. The low-scale continuous activation of blood coagulation in CAD patients could lead to parallel FXIII and fibrinogen consumption. As the same amount of thrombin activates more Leu34 FXIII than Val34 FXIII, increased FXIII consumption might be responsible for the decreased FXIII levels in Leu34 homozygous CAD patients.     

Coagulation factor XIII and cardiovascular disease in UK Asian patients undergoing coronary angiography

Possession of the coagulation factor XIII Val34Leu (FXIIIVal34Leu) polymorphism is associated with protection against myocardial infarction (MI) in Caucasians, in the absence of features of insulin resistance. The role of this polymorphism in the UK Asian population, with its high prevalence of insulin resistance and ischaemic heart disease, is unknown. We investigated the frequency of genotypes at this polymorphism, and measures of circulating FXIII in a group of UK Asians attending for coronary angiography. Genotype at the FXIIIVal34Leu polymorphism was not associated with MI. FXIII B-subunit levels correlated with waist: hip ratio (r = 0.19, p <0.005), HbA1c (r = 0.18, p <0.05), fasting triglycerides (r = 0.21, p <0.005), total cholesterol (r = 0.29, p <0.0005) and PAI-1 antigen (r = 0.24, p <0.005). An association between FXIIIVal34Leu and FXIII cross-linking activity was confirmed in these subjects (one-way ANOVA p <0.0005). This evidence does not support the hypothesis that FXIIIVal34Leu is protective against MI in the UK Asian population. FXIII B-subunit levels are strongly linked to risk factors for cardiovascular disease, suggesting an underlying association with insulin resistance.     

Factor XIa and tissue factor activity in patients with coronary artery disease

It has been established that inflammation and enhanced pro-coagulant activity are associated with the pathogenesis of atherosclerotic vascular disease. We evaluated and compared the contributions of the factor (F)XIa and tissue factor (TF) activity in plasma of patients with coronary artery disease (CAD). Citrate plasma was obtained prior to therapy from 53 patients with stable angina (29 with a history of previous myocardial infarction; CAD-MI) and 30 with acute coronary syndrome (ACS) within 12 hours from pain onset. Four ACS patients treated with heparin were excluded. FXIa and TF activity were determined in clotting assays based upon the prolongation of clotting time by inhibitory monoclonal antibodies. Twenty-five of 26ACS patients (96%) and 22 of 29 CAD-MI patients (76%) had quantifiable FXIa (50 +/- 33 and 42 +/- 45pM, respectively). Ten of 26 (38%) ACS patients and only three of 53 (6%) stable CAD patients showed TF activity (<0.4pM). No FXIa or TF activity was observed in age-matched healthy controls (n = 12). For both CAD-MI and ACS patients, there were correlations (p < 0.05) between FXIa and interleukin-6 (R(2) = 0.59 and 0.39, respectively) and between FXIa and TAT (R(2) = 0.64 and 0.63, respectively). In conclusion, the majority of ACS and CAD-MI patients have circulating FXIa that correlates with markers of coagulation and inflammation.     

Association between adiponectin gene polymorphisms and coronary artery disease across different populations

Objective

Many studies have suggested that adiponectin gene might be involved in the development of coronary artery disease (CAD). However, the results have been inconsistent. In this study, the authors performed a meta-analysis to assess the associations of + 45T/G, + 276G/T and − 11377C/G polymorphisms in adiponectin gene with CAD susceptibility.

Methods

Published literature from PubMed and EMBASE databases were searched. Pooled odds ratio (OR) and corresponding 95% confidence interval (CI) were calculated using fixed- or random-effects model.

Results

Sixteen studies (4394 cases / 8187 controls) for + 45T/G polymorphism, fifteen studies (3569 cases / 7463 controls) for + 276G/T polymorphism, and thirteen studies (3531 cases / 7072 controls) for − 11377C/G polymorphism were included in the meta-analysis. The overall results showed that there was a statistically significant association between − 11377C/G polymorphism and CAD (G vs. C: OR = 1.15, 95%CI 1.07-1.24).Similar results were observed among European (G vs. C: OR = 1.11, 95%CI 1.02-1.20) and East Asian populations (G vs. C: OR = 1.27, 95%CI 1.11-1.45). However, no significant association was found for + 45T/G or + 276G/T polymorphism with CAD susceptibility.

Conclusions

The meta-analysis indicated the significant association of − 11377C/G polymorphism, but not + 45T/G or + 276G/T polymorphism, with CAD susceptibility. However, large-scale studies with the consideration of gene-gene and gene-environment interactions should be conducted to investigate the associations in future.     

Prevalence and biologic profile of aspirin resistance in patients with angiographically proven coronary artery disease

BACKGROUND: Aspirin protects from cardiovascular events. However, a number of patients who take this drug suffer events, probably due to aspirin resistance. The role of certain biologic variables that may affect resistance is still uncertain. AIM: To determine the prevalence of aspirin resistance in patients taking this drug and to test if resistance is related to haemostatic, inflammatory and lipidic variables. METHODS: Platelet function measured with PFA-100 was studied in 268 patients (185 men) with stable coronary disease who took aspirin (100 to 300 mg/day). Aspirin resistance was defined when epinephrine closure time <174 s. Results of lipoprotein(a) are expressed in median (interquartile range). RESULTS: Aspirin resistance was found in 16% of cases. Patients with aspirin resistance had higher levels of Apolipoprotein B (109.27+/-27.65 vs 100.92+/-23.77 mg/dl; p<0.05), lipoprotein(a) [20.37 (4.83-36.72) vs 10.02 (1.88-25.41); p<0.01], Platelet Count (241.42+/-75.35 vs 213.94+/-56.74 mm(3); p<0.05) and fibrinogen (388.93+/-107.27 vs 354.33+/-89.35 mg/dl; p<0.05). We used the logistic regression analysis to detect the independent predictors of aspirin resistance. Lipoprotein(a) was found to be the only independent risk factor to identify aspirin resistance (p<0.05; OR: 1.302; CI 95%: 1.003-1.688). CONCLUSIONS: Although the potential mechanisms of aspirin resistance still remains uncertain, we found that platelet responsiveness to aspirin is reduced in patients with high levels of Apolipoprotein B and lipoprotein(a). Our work demonstrate that lipoprotein(a) is an independent risk factor for aspirin resistance possibly due to the interaction of Apolipoprotein(a) with human platelets.     

Synergistic association of DNA repair relevant gene polymorphisms with the risk of coronary artery disease in northeastern Han Chinese

Evidence is mounting suggesting that DNA damage is implicated in the development and progression of atherosclerosis. To yield more information, we focused on six well-characterized polymorphisms from four DNA repair-relevant candidate genes, viz. XRCC1 (rs1799782 and rs25487), XRCC3 (rs861539), MTHFR (rs1801133 and rs4846049), and NQO1 (rs1800566), to identify and characterize their potential gene-to-gene interactions in susceptibility to coronary artery disease (CAD) in Han Chinese. This was a hospital-based case-control study involving 1142 patients diagnosed with CAD and 1106 age- and gender-matched controls. All participants were angiographically confirmed. Risk estimates were expressed as odds ratio (OR) and 95% confidence interval (95% CI). All six examined polymorphisms met Hardy-Weinberg equilibrium. Overall there were significant differences in the genotype/allele distributions of MTHFR gene rs1801133 and rs4846049 (both P ≤ 0.005), and in the genotype distributions of XRCC1 gene rs1799782 (P = 0.002) between patients and controls. The adjusted risk of having CAD was more evident for rs1799782 (OR = 1.53; 95% CI: 1.16-2.02; P = 0.003), rs1801133 (OR = 1.54; 95% CI: 1.22-1.94; P < 0.001), and rs4846049 (OR = 1.74; 95% CI: 1.13-2.69; P = 0.013) under the recessive model. Interaction analyses indicated that the overall best multifactor dimensionality reduction (MDR) model included rs4846049, rs1801133, and rs1799782, and this model had a maximal testing accuracy of 0.6885 and a cross-validation consistency of 10 out of 10 (P = 0.0030). Further interaction entropy graph bore out the validity of this MDR model. Taken together, our findings demonstrate a contributory role of genetic defects in XRCC1 and MTHFR genes, both individually and interactively, in the development of CAD in Han Chinese.     

Vagal neurostimulation in patients with coronary artery disease

We tested the hypotheses that (1) progression of coronary artery disease (CAD) increases sympathetic inflow to the heart, thus impairing cardiac blood supply, and (2) reduced sympathetic tone improves cardiac microcirculation and ameliorates severity of anginal symptoms. Electrical irritation of the nerve auricularis--a sensitive ramus of the vagus nerve--provides a central sympatholytic action. Using this technique, we studied the effects of vagal neurostimulation (VNS) on hemodynamics, the content of atrial noradrenergic nerves and the microcirculatory bed of CAD patients. VNS was performed in the preoperative period of CAD patients with severe angina pectoris. The comparison groups consisted of untreated patients with CAD or Wolff-Parkinson-White syndrome. Atrial tissue of patients with this syndrome (n = 6); with effort angina (n = 14); with angina at rest (n = 10); and with severe angina treated with VNS (n = 8) contained the following volume percentages of noradrenergic nerves: 1.7+/-0.1%, 1.3+/-0.3%, 0.5+/-0.1% (p < 0.05 vs. the other groups) and 1.3+/-0.2%, respectively. In these groups, cardiac microcirculatory vessels (diameter, 10-20 microm) had the following densities: 2.7+/-0.2%, 3.4+/-0.2%, 2.0+/-0.4% (p < 0.05 vs. the other groups) and 3.3+/-0.3%, respectively. VNS treatment abolished angina at rest, decreased heart rate and blood pressure. It improved left ventricular ejection fraction from 50+/-1.5% to 58+/-1.0% (p < 0.05), also changing left ventricular diastolic filling. The ratio of time velocity integrals of the early (Ei) to late (Ai) waves increased from 1.07+/-0.12 to 1.65+/-0.17 after VNS (p < 0.05). In electrocardiograms of VNS-treated patients, QRS- and QT-duration were shortened. the PQ-interval did not change, but T-wave configuration improved. In the postoperative period, heart failure occurred in 90% of the control group. vs. 12% in patients treated with VNS (p < 0.05). We conclude that CAD is characterized by overactivity of sympathetic cardiac tone. Vagal stimulation reduced sympathetic inflow to the heart, seemingly via an inhibition of norepinephrine release from sympathetic nerves. VNS' sympatholytic/vagotonic action dilated cardiac microcirculatory vessels and improved left ventricular contractility in patients with severe CAD.     

Genetic polymorphisms and coronary artery disease in the south of France

Vascular disease is a multifactorial disease that involves atherosclerotic and thrombotic factors. Genetic polymorphisms have been associated with myocardial infarction and angina pectoris. The aim of the present study was to assess the relationship between some genetic polymorphisms and myocardial infarction (MI) or vasospastic angina pectoris in a population from southern France. Genetic polymorphisms of the renin angiotensin system (the D/I polymorphism of the ACE gene and the A1166C polymorphism of the angiotensin II type 1 receptor [AT1R]) and of haemostatic factors (the -675 4G/5G polymorphism of the plasminogen-activator inhibitor 1[PAI-1] gene, and the G to T common point mutation in exon 2, codon 34 of the Factor XIII A-subunit gene) were examined. We assessed the genotype distribution in consecutive coronary artery disease (CAD) patients with MI (n = 201) and vasospastic angina pectoris (n = 43) and in 244 healthy controls comparable in age, sex, body mass index and total cholesterol level. The genotype distribution of AT1R polymorphism was significantly different between controls and patients, the prevalence of the C allele carriers being higher in patients with MI after the age of 45 than in control individuals (61 vs 45%, p <0.01), leading to an odds ratio (OR) of 2 (CI: 1.2-3.4). When looking at the group of patients with vasospastic angina the difference was even higher (76 vs 45%, p <0.01) yielding an OR of 4.3 (CI: 1.4-17.4). Genotype distributions of ACE, PAI-1 and Factor XIII polymorphisms were similar in patients and in controls. This study is in favor of a role of ATIR gene polymorphism in myocardial infarction and vasospastic angina.     

Brain derived neurotrophic factor, cardiopulmonary fitness and cognition in patients with coronary artery disease

Objective

To assess serum brain derived neurotrophic factor (BDNF) concentrations as a correlate of cardiopulmonary fitness and as a predictor of cognitive performance in subjects with coronary artery disease (CAD).

Methods

Serum BDNF concentrations were assayed by ELISA and fitness was assessed using a standardized exercise stress test. The Mini Mental Status Examination (MMSE), California Verbal Learning Test 2nd Ed., Stroop, Trail Making Test B and the Digit Symbol-Coding task were administered. The val66met BDNF genotype and serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations were determined as potential confounders.

Results

In subjects with CAD (n = 88; 85.2% male, mean age 62.8 ± 10.5 yr), cardiopulmonary fitness was associated with higher serum BDNF concentrations (β = .305, p = .013). Higher serum BDNF concentrations were associated with higher MMSE scores (F(1, 87) = 15.406, p < .0005) and better performance on the Digit Symbol-Coding task (F(1, 87) = 9.620, p = .003). IL-6, TNF-α and the val66met genotype did not influence these results.

Conclusion

Serum BDNF concentrations were associated with cardiopulmonary fitness, psychomotor processing speed and overall cognition in subjects with CAD.     

Association study of three polymorphisms of TGF-beta1 gene with Alzheimer's disease

BACKGROUND: There is evidence that inflammatory processes may contribute to the development of Alzheimer's disease through production of cytokines and free radicals that damage neurones. A recent study has shown that transforming growth factor beta1 (TGF-beta1) signalling in astrocytes promotes Abeta production and could play a critical role in the formation of amyloid plaques in the brain. OBJECTIVES: To explore the impact of the -800 and -509 TGF-beta1 promoter polymorphisms and the +25 polymorphism on the risk of occurrence of Alzheimer's disease in a large population of sporadic cases and controls, and on the amyloid beta (Abeta) load in the brains of Alzheimer patients. METHODS: The TGF-beta1 genotypes of the three polymorphisms were determined in 678 sporadic Alzheimer's disease patients and 667 controls. They were also characterised, along with Abeta load, in the brains of 81 necropsy confirmed Alzheimer patients. RESULTS: No significant variations in the distribution of the genotypes and haplotypes were observed between Alzheimer patients and controls, or in the amount of Abeta deposition. CONCLUSIONS: These results do not suggest an influence of genetic variability at the TGF-beta1 gene locus on the occurrence of Alzheimer's disease.     

Asymptomatic coronary artery disease in patients with stroke. Prevalence, prognosis, diagnosis, and treatment.

The frequency of angiographically defined asymptomatic CAD in patients with carotid disease is 40%. Although the prognosis of patients with asymptomatic 1-vessel or 2-vessel CAD is good (annual cardiac mortality rate less than 2%), the prognosis of asymptomatic 3-vessel disease or left main CAD is substantially less favorable (annual cardiac mortality 5-8%). Preliminary data from nonrandomized studies suggest that coronary artery bypass surgery significantly lowers cardiac mortality in patients with asymptomatic 3-vessel or left main CAD. Further studies are needed to determine 1) vascular risk factor profiles that are predictive of asymptomatic CAD in patients with cerebrovascular disease and 2) the prevalence of asymptomatic CAD, especially 3-vessel and left main CAD, in patients with a variety of subtypes of cerebrovascular disease (e.g., carotid disease, atherosclerotic vertebrobasilar disease, cardioembolism, penetrating artery disease, stroke of undetermined cause). If the prevalence of asymptomatic 3-vessel or left main CAD is high in a subset of patients with cerebrovascular disease, a randomized study comparing coronary artery bypass surgery with best medical therapy (anti-ischemic agents, lipid-lowering therapy, and aspirin) may be warranted.     

Brain-derived neurotrophic factor gene polymorphisms and Alzheimer's disease

Several lines of evidence have made brain-derived neurotrophic factor (BDNF) an important candidate gene conferring risk for Alzheimer's disease (AD). Recently, three studies reported an association between two single-nucleotide polymorphisms (SNP)--i.e., C270T and G196A--in the BDNF gene and AD. This attempt to confirm these associations in a larger AD sample included examination of the linkage disequilibrium of these two SNPs. Comparison of 487 Japanese AD subjects with 471 cognitively normal elderly controls showed higher frequencies of the G allele (60.5 vs. 55.5%, p = 0.028) and of both the GG and GA genotypes (85.8 vs. 79.8%, p = 0.025) of the G196A polymorphism in AD subjects than in controls and higher frequency of the T allele of the C270T polymorphism in AD subjects who were negative for apolipotrotein E4 (2.0 vs. 4.4%, p = 0.035) or positive for AD family history (2.8 vs. 7.1%, p = 0.046). These findings suggest that BDNF gene polymorphisms play some role in the development of AD.     

Study of the HFE gene common polymorphisms in French patients with sporadic amyotrophic lateral sclerosis

Our objective was to investigate whether the C282Y (p.Cys 282 Tyr) and H63D (p. His 63 Asp) HFE polymorphisms were associated with sporadic amyotrophic lateral sclerosis (SALS) in the French population. We searched for a relation of HFE polymorphisms with the clinical characteristics of the disease. The HFE polymorphisms were studied in 824 patients with SALS and 583 controls. We compared the frequency of the polymorphisms between SALS and controls groups by univariate and multivariate statistics, taking into account gender, site, age-at-onset and survival. We did not observe significant difference in the frequency of H63D polymorphism between SALS and control group. We observed a significant difference for C282Y between patients and controls with a low frequency of the Y allele in patients (3.2%) compared to our control group (5.9%). Disease duration, distribution of gender, site-of-onset, age-at-onset did not differ between groups taking into account genotypes of each polymorphism. Our results in this large cohort of ALS patients indicate that H63D polymorphism is not associated with SALS in the French population. This conclusion does not exclude a weak effect of the HFE gene polymorphisms in certain ALS populations, or an effect of other rare HFE gene variants.