Association of the 894G>T polymorphism in the endothelial nitric oxide synthase gene with risk of venous thromboembolism in Chinese population

Introduction

Endothelium derived nitric oxide (NO) is a key mediator of vascular homeostasis. Endothelial nitric oxide synthase (eNOS) gene, by affecting the expression and functional activity of the eNOS enzyme, thereby reducing NO availability, may be implicated in venous thromboembolism (VTE). We investigated the eNOS G894T polymorphism in VTE patients in the Chinese population.

Materials and methods

A case-control study was conducted in a general hospital. Blood samples, collected from 462 consecutive patients with VTE and 462 healthy controls, were used for DNA extraction. Single nucleotide polymorphisms (SNP) of eNOS (894 G/T) were determined by allele specific-polymerase chain reaction (ARMS-PCR) analysis.

Results

The eNOS 894 G/T polymorphism alleles distribution was in agreement with the principle of Hardy-Weinberg equilibrium. The prevalence of homozygote, heterozygote and pathological homozygote for the eNOS G894T polymorphism in VTE patients was 79.7%, 18.1% and 2.2%, respectively (controls: 86.6%,12.3% and 1.1%). T allele distribution in the VTE (11.3%) and especially the male VTE patients (12.5%) was more common than in healthy controls (7.3%). The frequency of GT + TT genotype was significantly higher among the age ≤ 55 years patients in VTE group than in controls (20.1% vs. 12.2%, P = 0.033).

Conclusion

Our result demonstrates that the 894 G/T polymorphism variant of eNOS is a risk factor for VTE in Chinese population.     

Association of methylenetetrahydrofolate reductase polymorphisms with susceptibility to Alzheimer's disease

Background

Genetic risk factors play an important role in the pathogenesis of Alzheimer's disease (AD). In this case-control study, we examined the C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and their correlation with this pathology.

Objective

To verify the association between MTHFR C677T and A1298C polymorphisms and Alzheimer's disease.

Method

This work was conducted as a case–control study. Cases consisted of thirty-eight patients and 100 individuals without dementia constituted the control group. Genotyping of MTHFR polymorphisms was performed on patients and controls.

Result

Genetic analyses did not indicate a significant association between the MTHFR C677T mutation and AD (C/T: 63.15% versus 39%, p = 0.087). However, the genotype prevalence of the missense variant MTHFR A1298C was significantly different between patients and controls (A/C: 55% versus 7%, p < 10⁻³). Our data suggest an association between the MTHFR A1298C mutation and AD; however, the MTHFR C677T mutation did not contribute to susceptibility for AD.

Conclusion

The MTHFR A1298C polymorphism is a possible risk factor for Alzheimer's disease.     

Interaction between homocysteine and lipoprotein(a) increases the prevalence of coronary artery disease/myocardial infarction in women: a case-control study

Introduction

Our aim was to investigate the association of elevated homocysteine (Hcy) and lipoprotein(a) Lp(a) with the prevalence of coronary artery disease (CAD) and myocardial infarction (MI) and to investigate their interaction in both genders.

Materials and methods

955 (male/female: 578/377) consecutive patients admitted for coronary angiography were enrolled in the study. Lp(a), Hcy, vitamin B12, folic acid, MTHFR C677T polymorphism and traditional risk factors were determined.

Results

619 patients had significant (≥ 50%) stenosis (CAD+) and 341 had MI (MI+). CAD-MI- cases (n = 302) were considered as controls. Adjusted Hcy levels were significantly elevated only in the female CAD + MI + group that was related to decreased vitamin B12 levels. Lp(a) was elevated in the CAD + MI + group of both genders. Folic acid levels and MTHFR T677 allele frequency did not show significant difference. Moderate hyperhomocysteinemia (Hcy > 15 μmol/L) or elevated Lp(a) (> 300 mg/L) increased the risk of CAD (OR 2.27, CI 1.36-3.80 and OR 1.64, CI 1.03-2.61, respectively) and MI (OR 2.52, CI 1.36-4.67 and OR 1.89, CI 1.06-3.38, respectively) only in women. Only simultaneous but not isolated elevation of Hcy and Lp(a) conferred a significant, 3.6-fold risk of CAD in females and even higher (11-fold) risk in young females, which suggested an interactive effect.

Conclusions

Moderate hyperhomocysteinemia or elevated Lp(a) level associated with a risk of CAD and MI only in women. While isolated elevation of one of the two parameters represented a mild risk of CAD, their combined elevation highly increased the risk in females. No such effect was observed in males.     

Low protein Z levels, but not the intron F G79A polymorphism, are associated with unexplained pregnancy loss

Introduction

The present case-control study was designed in order to investigate the association between plasma protein Z (PZ) levels, the intron F G79A polymorphism and unexplained pregnancy loss.

Materials and Methods

51 women with at least two consecutive or three non-consecutive fetal losses between the 8th and 12th week of gestation and 47 apparently healthy parous women of reproductive age with no history of pregnancy loss (controls) were enrolled. Allele frequencies of the PZ intron F G79A polymorphism and PZ levels were measured.

Results

PZ levels (mg/L) were significantly lower in cases (mean±S.D. 1.28 ± 0.56) than controls (1.97 ± 0.76, p < 0.001) and in carriers of the A allele (1.46 ± 0.62), compared to GG homozygous subjects (1.72 ± 0.81, p = 0.044). A higher proportion of cases (41.2%) were PZ-deficient (< 1 mg/L), compared to controls (10.6%, p = 0.001). No significant difference in the frequency of at least one A allele carriers was observed between cases (39.2%) and controls (40.4%).

Conclusion(s)

It is possible that low PZ levels are a novel risk factor for unexplained recurrent miscarriage or fetal death. The presence of the F 79A allele is associated with significantly lower PZ levels, but, in the present study, was unrelated to unexplained early pregnancy loss.     

Lack of association between TLR4 Asp299Gly polymorphism and atherosclerosis: evidence from meta-analysis

Introduction

Toll like receptor 4 (TLR4) expression was found to increase markedly in human atherosclerotic lesions, notably on macrophages and endothelial cells. TLR4 Asp299Gly polymorphism was associated with a blunted receptor activity and a subsequently diminished inflammatory response, and may subsequently reduce atherosclerosis (AS) risk. However, the results of molecular epidemiological studies remained inconsistent.

Materials and methods

The PubMed, CNKI databases were searched for all articles available. The OR corresponding to the 95% confidence interval (95% CI) was used to assess the association between TLR4 Asp299Gly polymorphism and risk of AS.

Results

15 case-control studies with 9,989 cases and 6,746 controls were available for this analysis. For control subjects, G allele frequency of TLR4 Asp299Gly polymorphism was ranging from 0.045 to 0.085. The G allele and the AG/GG genotypes were not associated with significantly risk of AS (OR = 1.02, 95% CI = 0.83 - 1.26 for G versus A and OR = 0.96, 95% CI = 0.80 - 1.15 for AG/GG versus AA, respectively) by random effects model.

Conclusion

These findings indicated that TLR4 Asp299Gly polymorphism may not play a role in AS development.     

Detection of endogenous tissue factor levels in plasma using the calibrated automated thrombogram assay

Background

The calibrated automated thrombogram (CAT) assay measures thrombin generation in plasma.

Objective

Use the CAT assay to detect endogenous tissue factor (TF) in recalcified platelet-rich plasma (PRP) and platelet-free plasma (PFP).

Methods

Blood from healthy volunteers was collected into citrate and incubated at 37 °C with or without lipopolysaccharide (LPS) for 5 hours. PRP and PFP were prepared and clotting was initiated by recalcification. Thrombin generation was measured using the CAT assay.

Results

The lag time (LT) was significantly shortened in PRP prepared from LPS-treated blood compared with untreated blood (10 ± 3 min versus 20 ± 6 min), and this change was reversed by the addition of inactivated human factor VIIa. LPS stimulation did not change the peak thrombin. Similar results were observed in PFP (21 ± 4 min versus 35 ± 5 min). LPS stimulation also significantly reduced the LT of PRP and PFP derived from blood containing citrate and a factor XIIa inhibitor. Finally, a low concentration of exogenous TF shortened the LT of PFP prepared from unstimulated, citrated blood without affecting the peak thrombin.

Conclusion

Changes in LT in the CAT assay can be used to monitor levels of endogenous TF in citrated plasma.     

Catechol-O-methyltransferase gene Val108/158Met polymorphism in bipolar disorder

Backgrounds

Although several studies have tested the association between bipolar disorder (BD) and the Val108 (H, high-activity allele)/158Met (L, low-activity allele) polymorphism of the catechol-O-methyltransferase (COMT) gene, most of the results showed no significant association. However, an association between the H or L allele and bipolar disorder (BD), particularly, between L allele and rapid-cycling form has been reported; it has also been suggested that the variation in the COMT gene modifies the course of BD and there is a tendency for the L allele amongst the female patients. In this study, the researchers aimed to evaluate the association between BD and COMT gene H/L polymorphism considering the influence of gender in a group of Turkish patients.

Method

One hundred and thirty-five BD patients (71 male and 64 female) and 171 controls were included. Polymerase chain reaction-based endonuclease digestion method was used.

Results

Genotypic distribution in patients and controls were in Hardy-Weinberg equilibrium. No significant difference was found in genotypic and allelic frequencies between patients and controls. However, female patients had H allele more frequently than male patients and female healthy controls. Females had more depressive and less manic episodes than males. Number of total episodes was associated with H allele in all patients.

Conclusion

Distribution of COMT genetic polymorphism was not significantly different between the patients and controls. However, it has been found an association of H allele with female patients and number of episodes among all patients.     

The G894T polymorphism on endothelial nitric oxide synthase gene is associated with increased coronary heart disease among Asia population: evidence from a Meta analysis

Introduction

Growing studies have revealed the underlying association between eNOS 894 G/T (rs1799983) polymorphism and coronary heart disease (CHD) among Asia population. Results from these studies remained conflicting. We conducted this meta-analysis to estimate the overall CHD risk of eNOS 894 G/T polymorphism regarding Asia population.

Materials and methods

Up to October 2011, databases including PubMed, Embase and CNKI (China National Knowledge Infrastructure) were searched to access the relevant genetic association studies. Summary odds ratios and corresponding 95% confidence intervals (CIs) for eNOS 894 G/T polymorphism and CHD risk were estimated using fixed or random-effects models when appropriate.

Results

18 case-control studies with 2,994 cases and 3,130 controls were available for this study, including 13 studies of East-Asia descendents, 5 studies of Non East-Asian descendents. The mean T allele frequency was 0.111 in the East-Asia population and 0.147 in the Non East-Asia population, respectively. The summary OR for CHD associated with the T allele was 1.52 (95% confidence intervals (95%CI), 1.37-1.69) by random effects model. Similarly, significantly increased risks were observed in the East-Asia population (OR = 1.54; 95%CI = 1.35-1.76) and in the Non East-Asia population (OR = 1.48; 95%CI = 1.24-1.77), respectively.

Conclusions

This meta-analysis indicated that eNOS 894 G/T polymorphism may play an important role in CHD development among Asia population.     

Les thromboses veineuses cérébrales en milieu hospitalier à Ouagadougou (Burkina Faso)

Introduction

Cerebral venous thrombosis (CVT) is a rare condition difficult to diagnose because of the wide variability of the clinical presentations. The goal of our survey was to study the clinical, etiological and progressive aspects of the CVT in Burkina.

Patients and method

We conducted a prospective study for two years, including patients with a diagnosis of CVT based on clinical and imaging criteria. Age, gender, clinical findings and results of complementary tests were recorded as was the clinical outcome.

Results

The study included 17 patients (seven men and ten women) mean age 42.5 years. The inaugural signs were sub-acute in two-thirds of the patients. Headache was a constant finding (n = 17 patients, 100%); 15 patients (88%) had unilateral or bilateral motor deficits. An infectious syndrome was common (60%). The brain CT scan generally revealed spontaneous high density signals from a sinus. d-dimeres were high in 15 cases. Four patients were HIV-1 seropositive and four had rhino-sinusitis. The other etiological factors were rare. Heparin was administred in 80% of patients, followed by oral anticoagulation for three months on average.

Conclusion

Our cohort presents a relatively different clinical picture compared with the literature due to the high frequency of the infectious etiologies. A prospective multicentric study with more specific diagnostic tools could be useful to learn more about the epidemiology of CVT in Subsaharan Africa.     

Primary atherothrombotic occlusive vascular events in premenopausal women with history of adverse pregnancy outcome

Objective

To determine if adverse pregnancy outcomes are associated with atherothrombotic occlusive vascular disease (AOVD) in premenopausal women.

Design

Retrospective matched case-control study.

Setting

Tertiary, university-affiliated medical center.

Population

Women aged less than 50 years treated for an AOVD (primary cerebrovascular, myocardial, or peripheral arterial ischemic event) from 1995 to 2004.

Method

The files were reviewed for classical risk factors for AOVD and complications of pregnancy (abortions, pregnancy-induced hypertension, preeclampsia, gestational diabetes, intrauterine growth restriction (IUGR), fetal loss and preterm delivery). Findings were compared with healthy women matched for age and body mass index.

Main outcome measures

Past pregnancy complications in premenopausal women with AOVD.

Results

Of the 101 women with AOVD, 53 had a myocardial ischemic event, 33 a cerebrovascular event, and 15 a peripheral ischemic arterial event. On multivariate analysis, IUGR (OR 8.41, 95% CI 2.36-29.9, p = 0.001) and more than one pregnancy complication (OR 13.7, 95% CI 1.56-120, p = 0.02) were found to be independent significant variables associated with AOVD.

Conclusion

IUGR and composite pregnancy complications are independent significant variables associated with AOVD in premenopausal period. Pregnancy outcome might serve as a means to identify patients who may require increased medical surveillance and preventive measures for later vascular disease.     

Association of methylenetetrahydrofolate reductase A1298C polymorphism but not of C677T with multiple sclerosis in Tunisian patients

Background and objective

Multiple sclerosis (MS) is a chronic neurological disease characterized by central nervous system (CNS) inflammation and demyelination of nerve axons. The aim of this study was to investigate a possible association between the methylenetetrahydrofolate reductase (MTHFR) gene and multiple sclerosis in Tunisian patients.

Patients and methods

The genotyping of two missense variants of the methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C was performed in 80 multiple sclerosis patients and 200 healthy controls.

Results

No significant differences were found in the frequency of the MTHFR C677T polymorphism between MS patients and healthy controls. However, the genotype prevalence of the missense variant MTHFR A1298C was significantly different between patients and controls (A/C: 55% versus 7%, p < 10⁻³; C/C: 13.75% versus 0%, p < 10⁻³, respectively).

Conclusion

Although our preliminary findings suggest no association between the MTHFR C677T variants and MS, there is evidence to suggest a significant association between the MTHFR A1298C polymorphisms and MS.     

The impact of platelet membrane glycoprotein Ib alpha and Ia/IIa polymorphisms on the risk of thrombosis in the antiphospholipid syndrome

Background

Pathogenesis of thrombus formation in antiphospholipid syndrome (APS) is not clear. Platelet membrane glycoprotein (GP) receptors play important roles in development of thrombosis.

Objectives

We investigated the association between development of thrombosis in APS and polymorphisms of GPIb alpha variable number of tandem repeats (VNTR), Kozak, and GPIa C807T.Patients/MethodsSixty patients with APS (30 with proven thrombosis and 30 without thrombosis) and 63 controls were included. Presence of GPIa C807T polymorphism was determined with real-time PCR and GPIb alpha Kozak and VNTR polymorphisms by conventional PCR.

Results

Frequency of C807T TT genotype was significantly higher in APS with thrombosis than APS without thrombosis (p = 0.023) and also in APS with multiple thrombi compared to APS without thrombi (p = 0.023). Frequency of Kozak TC genotype was higher in APS with arterial thrombosis compared to APS with venous thrombosis, controls, and APS without thrombosis (p = 0.03, p = 0.0007, and p = 0.0024 respectively). D allele frequency and D allele carrier state for VNTR were significantly less in APS than controls (p = 0.0018 and p = 0.0046 respectively).

Conclusions

C807T TT genotype may confer a risk for thrombosis and Kozak TC genotype for arterial thrombosis. D allele of VNTR may protect from APS. No patients with C807T TT or Kozak TC genotypes carried the protective DD genotype of VNTR. These polymorphisms may increase risk for both arterial and venous thrombosis. The utility of prophylaxis with anti-platelet drugs in at least a subgroup of APS patients should be investigated with clinical trials.     

Lack of association between a functional genetic variant of connexin 37 and ischemic stroke in a Taiwanese population

Introduction

Connexin 37, encoded by the GJA4 gene, protects against atherosclerosis. A recent study reported an association between polymorphism rs1764391 at GJA4 and ischemic stroke in a Chinese population. We aimed to replicate this result.

Materials and Methods

A total of 958 ischemic stroke patients and 2196 controls were enrolled for the study. All participants were Chinese residing in Taiwan. Logistic regression analysis with adjustment for traditional risk factors was used to estimate the genetic effect. We also performed stratification analyses by sex and stroke subtypes. Literature reviews were conducted for available genetic association studies investigating rs1764391 and cardiovascular phenotypes.

Results

We did not find any significant association for overall stroke (p = 0.87) or from any subset analyses. Eight studies addressing the associations between rs1764391 and cardiovascular phenotypes had a sample size greater than 1000. Including the present study, five out of the eight large-scale studies found no association.

Conclusions

GJA4 polymorphism is not associated with stroke risk in the Taiwanese population.     

Attentional bias for emotional faces in paediatric anxiety disorders: An investigation using the emotional go/no go task

Background

The present study examined contextual modulation of attentional control processes in paediatric anxiety disorders.

Method

Anxious children (N = 20) and non-anxious controls (N = 20) completed an emotional Go/No Go task in which they responded on some trials (i.e., Go trials) when neutral faces were presented amongst either angry or happy faces to which children avoided responding (i.e., No Go trials) or when angry and happy faces were presented as Go trials and children avoided responding to neutral faces.

Results

Anxious girls were slower responding to neutral faces with embedded angry compared with happy face No Go trials whereas non-anxious girls were slower responding to neutral faces with embedded happy versus angry face No Go trials. Anxious and non-anxious boys showed the same basic pattern as non-anxious girls. There were no significant group differences on No Go trials or when the emotional faces were presented as Go trials.

Conclusions

Results are discussed in terms of selective interference by angry faces in the control of attention in anxious girls.     

Lack of evidence for association between factor XIII-A Val34Leu polymorphism and ischemic stroke: A meta-analysis of 8,800 subjects

Introduction

Epidemiological studies have evaluated the association between factor XIII-A (FXIII-A) Val34Leu polymorphism and risk of ischemic stroke, but the results remain inconclusive. This meta-analysis was therefore designed to clarify these controversies.

Methods

Systematic searches of electronic databases Embase, PubMed and Web of Science, as well as hand searching of the references of identified articles and the meeting abstracts were performed. Study selection, data abstraction and study quality evaluation (using the Newcastle-Ottawa Scale, NOS) were independently conducted in duplicate. Statistical analyses were performed using software Review Manager (Version 5.1.2) and Stata (Version 11.0). The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were performed. Fixed or random effects model was separately used depending on the heterogeneity between studies. Publication bias was tested by funnel plot, Egger's regression test and Begg's test. Sensitivity analysis was conducted by limiting the meta-analysis to the high quality studies (NOS score≥8).

Results

A total of 16 studies including 3,807 cases and 4,993 controls were combined showing no evidence of association between FXIII-A Val34Leu polymorphism and ischemic stroke (for Val/Leu vs. Val/Val : OR = 0.95, 95%CI = 0.77-1.16; for Leu/Leu vs. Val/Val: OR = 0.90, 95%CI = 0.73-1.11; for dominant model: OR = 0.97, 95%CI = 0.81-1.17; for recessive model: OR = 0.95, 95%CI = 0.77-1.17). In the subgroup analyses by study design, ethnicity and specific subtypes (small-vessel occlusive ischemic stroke and large-artery atherosclerotic ischemic stroke ), there was lack of evidence for the association.

Conclusions

This meta-analysis indicates that there is no evidence for association between factor XIII-A Val34Leu polymorphism and ischemic stroke.     

Lipoprotein lipase Ser447Ter polymorphism associated with the risk of ischemic stroke: a meta-analysis

Introduction

Previous studies suggested lipoprotein lipase (LPL) Ser447Ter and Asn291Ser polymorphisms were associated with the risk of ischemic heart disease, however, their effects on ischemic stroke were controversial. A meta-analysis was performed to assess the associations between these two LPL polymorphisms and the risk of ischemic stroke.

Methods

The electronic databases PubMed and Embase were used to identify relevant studies by two interviews independently. The pooled odds ratios (ORs) and weighted mean differences (WMD) with 95% confidence interval (CI) were estimated for the risk of ischemic stroke and the plasma lipids in various Ser447Ter genotypes respectively. A fixed or random effect model was selected for pooling data based on homogeneity test.

Results

13 studies including 4,681 ischemic stroke cases and 8,516 controls were involved in this meta-analysis. Overall, LPL Ter447 variant was associated with a significantly reduced risk for ischemic stroke (OR = 0.79, 95% CI: 0.68-0.93) both in Caucasian (OR = 0.87, 95% CI: 0.77-0.97) and East-Asian (OR = 0.65, 95% CI: 0.43-0.99), whereas no significant association of Ser291 variant was observed (OR = 1.25, 95% CI: 0.96-1.63). The Ser447Ter polymorphism may be more important in association with the decreased risk of atherosclerotic stroke (OR = 0.44, 95% CI: 0.32-0.62) which derived from significantly increased high density lipoprotein cholesterol, decreased triglyceride and total cholesterol in Ter447 carriers compared with non-carriers.

Conclusions

This meta-analysis indicated that LPL Ser447Ter polymorphism was associated with a significant reduction in the risk of ischemic stroke, especially atherosclerotic stroke subtype in both Caucasian and East-Asian.     

Amniotic fluid chemokines and autism spectrum disorders: an exploratory study utilizing a Danish Historic Birth Cohort

Introduction

Elevated levels of chemokines have been reported in plasma and brain tissue of individuals with Autism Spectrum Disorders (ASD). The aim of this study was to examine chemokine levels in amniotic fluid (AF) samples of individuals diagnosed with ASD and their controls.

Material and methods

A Danish Historic Birth Cohort (HBC) kept at Statens Serum Institute, Copenhagen was utilized. Using data from Danish nation-wide health registers, a case-control study design of 414 cases and 820 controls was adopted. Levels of MCP-1, MIP-1α and RANTES were analyzed using Luminex xMAP technology. Case-control differences were assessed as dichotomized at below the 10th percentile or above the 90th percentile cut-off points derived from the control biomarker distributions (logistic regression) or continuous measures (tobit regression).

Results and conclusion

AF volume for 331 cases and 698 controls was sufficient for Luminex analysis. Including all individuals in the cohort yielded no significant differences in chemokine levels in cases versus controls. Logistic regression analyses, performed on individuals diagnosed using ICD-10 only, showed increased risk for ASD with elevated MCP-1 (elevated 90th percentile adjusted OR: 2.32 [95% CI: 1.17-4.61]) compared to controls. An increased risk for infantile autism with elevated MCP-1 was also found (adjusted OR: 2.28 [95% CI: 1.16-4.48]). Elevated levels of MCP-1 may decipher an etiologic immunologic dysfunction or play rather an indirect role in the pathophysiology of ASD. Further studies to confirm its role and to identify the potential pathways through which MCP-1 may contribute to the development of ASD are necessary.     

ABCB1 C3435T polymorphism and risk of adverse clinical events in clopidogrel treated patients: a meta-analysis

Introduction

The ABCB1 C3435T polymorphism limits oral bioavailability of clopidogrel and may influence prognosis of patients treated with clopidogrel. Several studies have examined the association between the C3435T polymorphism and risk of adverse clinical events in clopidogrel treated patients, but the results were inconsistent. To assess the role of the C3435T polymorphism in the impact on clinical outcomes, a meta-analysis was conducted.

Methods

6 studies with 10,153 subjects were included in this meta-analysis. Fixed- or random-effects model was chosen according to heterogeneity. Publication bias was evaluated by fail-safe numbers.

Results

The association of the C3435T polymorphism with risk of overall recurrent ischemic events in clopidogrel treated patients was not statistically significant for all genetic models (OR = 1.13, 95%CI: 0.78-1.64, P = 0.51; OR = 1.15, 95%CI: 0.99-1.33, P = 0.07; OR = 1.19, 95%CI: 0.81-1.76, P = 0.37). Significant association was identified between the C3435T polymorphism and risk of short-term recurrent ischemic events (OR = 1.55, 95% CI: 1.09-2.20, P = 0.01; OR = 1.41, 95% CI: 1.06-1.87, P = 0.02; OR = 1.77, 95% CI: 1.19-2.63, P = 0.005). No statistically significant association between the C3435T polymorphism and stent thrombosis (OR = 0.79, 95% CI: 0.47-1.32, P = 0.37) or bleeding (OR = 0.98, 95% CI: 0.79-1.21, P = 0.82) was identified. The results may be affected by publication bias.

Conclusions

This meta-analysis failed to show an association between the ABCB1 C3435T polymorphism and risk of overall recurrent ischemic events, stent thrombosis or bleeding in clopidogrel treated patients. However, the association between TT homozygotes of the C3435T polymorphism and risk of short-term recurrent ischemic events may exist, but needs more studies to confirm.     

Risk modification for postoperative pulmonary embolism: timing of postoperative prophylaxis

Introduction

Risk factors for postoperative pulmonary embolism can often not be modified and are patient related. The purpose of this case control study was to identify possible modifiable risk factors for postoperative pulmonary embolism.

Materials and methods

We undertook a case control study among 210,269 patients who underwent noncardiac surgery from 2000 to 2009 at the Erasmus Medical Center. Case subjects were all 199 (0.09%) patients who experienced a pulmonary embolism within 30 days after surgery. From the remaining patients, 1 control was selected for each case and was stratified according to calendar year. For cases and controls, information was obtained regarding risk factors and the type and dose of thromboprophylaxis as well as the time of postoperative initiation.

Results

Overweight, surgery for malignancy, a history of cerebrovascular disease and a history of thromboemblic diseases, intraoperative blood transfusions and delayed use of thromboprophylaxis were more common in cases than in controls. After correction delayed use of thromboprophylaxis was associated with a 4 fold increased risk (OR 4.1; 95% CI: 2.1 - 7.7) for postoperative pulmonary embolism.

Conclusion

Delayed timing of postoperative thromboprophylaxis is an important modifiable risk factor for postoperative pulmonary embolism after noncardiac surgery. This study emphasises the importance of on time administration of thromboprophylaxis.     

G-455A polymorphism of β-fibrinogen gene and the risk of premature myocardial infarction in Greece

Introduction

There are limited and controversial data regarding the impact of G-455A polymorphism of β-fibrinogen gene in the pathogenesis of premature myocardial infarction (MI). We examined whether the G-455A polymorphism of β-fibrinogen gene is associated with the development of MI ≤ 35 years of age.

Methods

We recruited 181 consecutive patients who had survived their first acute MI ≤ 35 years of age (mean age = 32.2 ± 3.4 years). The control group consisted of 129 healthy individuals matched with cases for age and sex, without a family history of premature coronary heart disease. G-455A polymorphism of β-fibrinogen was tested with polymerase chain reaction and reverse hybridization.

Results

There was a higher prevalence of carriers of the A allele (GA+AA genotype) in controls than in patients (odds ratio [OR] 0.57, 95% confidence interval [CI] 0.36 to 0.91, p = 0.02). G-455A polymorphism of β-fibrinogen gene was associated with lower risk for acute MI (OR 0.46, 95% CI 0.25 to 0.83, p = 0.01) after adjusting for major cardiovascular risk factors. Fibrinogen levels were higher in patients compared to controls [332 (292-385) vs. 311 (262-373) mg/dL, p = 0.01], but the adjusted for classical risk factors fibrinogen levels did not differ (OR 1.003, 95% CI 0.99 to 1.01, p = 0.37). Patients possessing the A allele did not differ in their fibrinogen and lipid levels compared to patients with the -455GG genotype.

Conclusions

Our data indicate that the presence of the G-455A polymorphism of β-fibrinogen gene has a “protective effect” against the development of non-fatal acute MI ≤ 35 years of age in Greece.