Lack of association of a common polymorphism of the plasminogen activator inhibitor-1 gene with coronary artery disease and myocardial infarction

Genetic factors, risk prediction and AI application of thrombotic diseases

In thrombotic diseases, coagulation, anticoagulation, and fibrinolysis are three key physiological processes that interact to maintain blood in an appropriate state within blood vessels. When these processes become imbalanced, such as excessive coagulation or reduced anticoagulant function, it can lead to the formation of blood clots. Genetic factors play a significant role in the onset of thrombotic diseases and exhibit regional and ethnic variations. The decision of whether to initiate prophylactic anticoagulant therapy is a matter that clinicians must carefully consider, leading to the development of various thrombotic risk assessment scales in clinical practice. Given the considerable heterogeneity in clinical diagnosis and treatment, researchers are exploring the application of artificial intelligence in medicine, including disease prediction, diagnosis, treatment, prevention, and patient management. This paper reviews the research progress on various genetic factors involved in thrombotic diseases, analyzes the advantages and disadvantages of commonly used thrombotic risk assessment scales and the characteristics of ideal scoring scales, and explores the application of artificial intelligence in the medical field, along with its future prospects.

Genotype Variations and Association between PAI-1 Promoter Region (4G/5G and -844G/A) and Susceptibility to Acute Myocardial Infarction and Chronic Stable Angina

The present study aimed at investigating the 4G/5G and -844G/A polymorphisms and plasma concentration of PAI-1 in patients with acute myocardial infarction (AMI) and chronic stable angina (CSA) in Indian population. It included 100 patients with AMI and stable angina and 100 healthy controls. All study subjects were typed for two PAI polymorphisms (4G/5G and -844G/A) through PCR-RFLP and level of PAI through ELISA. The comparison of AMI and CSA independently with control in terms of PAI-1 level was statistically significant but not between AMI and CSA. The frequency of 4G/4G and 4G/5G genotype and 4G allele was significantly higher in AMI cases than in control and was found to increase the risk of AMI. There was a significant relationship between 4G/5G polymorphism and AMI risk under the dominant and codominant genotype. The frequency of 4G/4G genotype and 4G allele was significantly higher in CSA cases than in control group and increases the risk of CSA. There was no significant association between 4G/5G polymorphism and CSA risk under recessive, dominant, and codominant models. The genotype and allelic frequencies difference between the cases (AMI and CSA) and control with regard to -844G/A polymorphisms were statistically nonsignificant. Also, we did not detect any significant association of -844G/A polymorphism with AMI and CSA in recessive, dominant, and codominant models. Along with the traditional risk factors, the 4G/5G allele polymorphism is an independent risk factor for the development of AMI. The detection of 4G/5G allele may therefore be helpful in primary prevention. Patients who carry the 4G/5G allele polymorphism have high concentrations of PAI-1, which might be involved in incidents leading to AMI. The present study for the first time revealed significant association of 4G/5G allele polymorphism with high risk of AMI in Indian population and will be helpful in identifying the genetic risk factors associated with AMI and CSA and for better management of diagnostic measures.

Genetic variations of renin-angiotensin and fibrinolytic systems and susceptibility to coronary artery disease: a population genetics perspective

BACKGROUND

Genetic predisposition is an important risk factor in coronary artery disease (CAD).This study was conducted to determine the polymorphism frequencies of the plasminogen activator inhibitor-1(PAI-1) gene 4G/5G, angiotensin-converting enzyme (ACE) gene I/D, and angiotensin II type 1 receptor (AT1) gene A1166C genotypes and to examine the role of these polymorphisms in CAD.

METHODS

Genomic DNAs obtained from 260 subjects (130 CAD patients and 130 control) were used in the study. ACE I/D and PAI-1 4G/5G polymorphism genotypes were determined using polymerase chain reaction (PCR) and electrophoresis. AT-1 A1166C polymorphism was determined using the PCR, restriction fragment length polymorphism (RFLP) and electrophoresis. The products amplified from AT1 gene by PCR were cut with HindIII restriction endonuclease and then analyzed by 2% agarose gel electrophoresis. The results were statistically analyzed with the chi-square test, Mann-Whitney U test, and independent two-sample t-test.

RESULTS

Allele frequencies showed statistically significant differences between the patient and control groups. There was no statistically significant difference in ACEI/D genotype frequencies between the twogroups. Likewise, no statistically significant difference was found in the AT1 A1166C genotype frequencies; however, a statistically significant difference was found in allele frequencies. The PAI-1 4G/5G genotype frequency was significantly higher in the patient group.

CONCLUSIONS

While there is a relationship between of PAI-1 gene 4G/5G polymorphism and CAD, ACE gene I/D and AT1 gene A1166C polymorphisms are not related. PAI-1 gene homozygous genotypes may be considered as a prognostic marker for CAD patients.

Atherosclerotic and thrombotic genetic and environmental determinants in Egyptian coronary artery disease patients: a pilot study

BACKGROUND

Coronary artery disease (CAD) is the leading cause of morbidity and mortality worldwide. Multiple genetic variants in combination with various environmental risk factors have been implicated. This study aimed to investigate the association of twelve thrombotic and atherosclerotic gene variants in combination with other environmental risk factors with CAD risk in a preliminary sample of Egyptian CAD patients.

METHODS

Twenty three consecutive CAD patients undergoing diagnostic coronary angiography and 34 unrelated controls, have been enrolled in the study. Genotyping was based on polymerase chain reaction and reverse multiplex hybridization. Five genetic association models were tested. Data distribution and variance homogeneity have been checked by Shapiro-Wilk test and Levene test, respectively; then the appropriate comparison test was applied. Spearman's rank correlation coefficient was used for correlation analysis and logistic regression has been performed to adjust for significant risk factors. Clustering the study participants according to gene-gene and gene-environment interaction has been done by Detrended Correspondence Analysis (DCA).

RESULTS

The univariate analysis indicated that the five variants; rs1800595 (FVR2; factor 5), rs1801133 (MTHFR; 5,10-methylenetetrahydrofolate reductase), rs5918 (HPA-1; human platelet antigen 1), rs1799752 (ACE; angiotensin-converting enzyme), and rs7412 and rs429358 (ApoE; apolipoprotein E) were significantly associated with CAD susceptibility under different genetic models. Multivariate analysis revealed clustering of the study population into three patient groups (P) and one control group. FVR2 was the most variant associated with CAD patients, combined with the factor V Leiden (FVL) variant in P1 cluster and with both ACE and MTHFR 667C > T in P2. Whereas, P3 was mostly affected by both MTHFR 667C > T and FXIII (factor 13) V89L mutations. When combined with traditional risk factors, P1 was mostly affected by dyslipidemia, smoking and hypertension, while P2 was mostly affected by their fasting blood sugar levels and ApoE variant.

CONCLUSIONS

Taken together, these preliminary results could have predictive value to be applied in refining a risk profile for our CAD patients, in order to implement early preventive interventions including specific antithrombotic therapy. Further large scale and follow-up studies are highly recommended to confirm the study findings.

Role of ACE and PAI-1 Polymorphisms in the Development and Progression of Diabetic Retinopathy

In the present study we determined the association of angiotensin converting enzyme (ACE) and plasminogen activator inhibitor-1 (PAI-1) gene polymorphisms with diabetic retinopathy (DR) and its sub-clinical classes in Pakistani type 2 diabetic patients. A total of 353 diabetic subjects including 160 DR and 193 diabetic non retinopathy (DNR) as well as 198 healthy controls were genotyped by allele specific polymerase chain reaction (PCR) for ACE Insertion/Deletion (ID) polymorphism, rs4646994 in intron 16 and PAI-1 4G/5G (deletion/insertion) polymorphism, rs1799768 in promoter region of the gene. To statistically assess the genotype-phenotype association, multivariate logistic regression analysis was applied to the genotype data of DR, DNR and control individuals as well as the subtypes of DR. The ACE genotype ID was found to be significantly associated with DR (p = 0.009, odds ratio (OR) 1.870 [95% confidence interval (CI) = 1.04-3.36]) and its sub-clinical class non-proliferative DR (NPDR) (p = 0.006, OR 2.250 [95% CI = 1.098-4.620]), while PAI polymorphism did not show any association with DR in the current cohort. In conclusion in Pakistani population the ACE ID polymorphism was observed to be significantly associated with DR and NPDR, but not with the severe form of the disease i.e. proliferative DR (PDR).

Polymorphism and synergism of angiotensin-converting enzyme (ACE) and plasminogen activator inhibitor-1 (PAI-1) genes in coronary artery disease

INTRODUCTION

Among the genetic factors for coronary artery diseases, PAI-1 4G/5G and ACE I/D polymorphisms can be noted. This study was carried out to investigate the association of these two polymorphisms and their synergism in coronary artery disease (CAD) from a sample of the Iranian population.

MATERIALS AND METHODS

Sixty-one patients with a history of CAD and 92 healthy controls participated in our study. After DNA extraction from leukocytes, PCR was performed to characterize PAI-1 4G/5G and ACE I/D polymorphisms, using an amplification refractory mutation system technique.

RESULTS

In the studied patients, PAI-1 polymorphisms were 24.6%, 45.9%, and 29.5% for 4G/4G, 4G/5G and 5G/5G, respectively; the values for controls were 20.7%, 42.2% and 37.0%. The distribution rates of genotypes I/I, I/D and D/D in patients accounted for 29.5%, 45.9% and 24.6%; in the control group these figures were estimated to be 40.2%, 40.2% and 19.6%.

CONCLUSION

Single and multivariate analyses showed a significant difference for the conventional risk factors, including hypertension, diabetes, hyperlipidemia, smoking and family history, for CAD between patients and controls (p value ≤ 0.001). However, no significant correlation was demonstrated considering ACE and PAI-1 polymorphisms either in association with 4G/4G or D/D genotypes or a combination of them in the Iranian population in the current study.

Endobiogeny: a global approach to systems biology (part 1 of 2)

Endobiogeny is a global systems approach to human biology that may offer an advancement in clinical medicine based in scientific principles of rigor and experimentation and the humanistic principles of individualization of care and alleviation of suffering with minimization of harm. Endobiogeny is neither a movement away from modern science nor an uncritical embracing of pre-rational methods of inquiry but a synthesis of quantitative and qualitative relationships reflected in a systems-approach to life and based on new mathematical paradigms of pattern recognition.

Association of tissue plasminogen activator and plasminogen activator inhibitor polymorphism with myocardial infarction: a meta-analysis

INTRODUCTION

To investigate whether t-PA Alu repeat insertion/deletion (I/D) and PAI-1 4G/5G genetic variations are associated with the risk of MI.

METHODS

We conducted a meta-analysis to assess the association between the t-PA I/D and PAI-1 4G/5G polymorphisms and risk of MI. We also performed subgroup analyses based on ethnicity (Caucasian, Asian, and African), gender and age. Forty one eligible studies including 12,461 cases and 14,993 controls were identified to evaluate the impact of PAI-1 4G/5G polymorphism on MI. Seven studies investigated the relationship between t-PA I/D and MI.

RESULTS

This meta-analysis revealed that the PAI-1 4G allele (4G/4G and 4G/5G genotype) was associated with an increased risk of MI compared with the 5G allele in the overall population (OR=1.094, 95% CI=1.021 - 1.172, p=0.011). The relative risks of MI for 4G/4G genotype was increased when compared to 5G/5G genotype and 5G allele, with odds ratio at 1.157 (95% CI 1.015 - 1.320, p=0.029) and 1.126 (95% CI =1.015 - 1.249, p=0.025). However, the results show that the 4G/5G polymorphism risk for MI was not associated with ethnicity stratification as Caucasian, Asian or African population. No substantial differences in the genotype distributions were observed in the MI group and control group along the lines of gender and age. After multivariable analysis t-PA I/D polymorphism showed no consistent association with MI.

CONCLUSIONS

This study suggests that the 4G/5G polymorphism of PAI-1 may be a risk factor for MI in overall populations.

4G/5G Polymorphism of the plasminogen activator inhibitor-1 gene is associated with multiple organ dysfunction in critically ill patients

OBJECTIVE

Impaired fibrinolysis is associated with a higher incidence of both multiple organ dysfunction and mortality in the intensive care unit (ICU). Plasminogen activator inhibitor (PAI)-1 is the chief inhibitor of fibrinolysis. We investigated the influence of the 4G/5G polymorphism (rs1799768) of the PAI-1 gene on the plasma PAI-1 level and the outcome of critically ill patients.

METHODS

In 41 consecutive patients admitted to the ICU, PAI-1 gene polymorphism was assessed, plasma PAI-1 and arterial lactate concentrations were measured and clinical severity scores were recorded.

RESULTS

Homozygotes for the 4G allele had higher plasma levels of PAI-1 antigen. The mean ± SD PAI-1 antigen level was 193.31 ± 167.93 ng/ml for the 4G/4G genotype, 100.67 ± 114.16 ng/ml for the 4G/5G genotype and 0.43 ± 0.53 ng/ml for the 5G/5G genotype. There was a significant correlation between plasma PAI-1 and arterial lactate concentrations, as well as between PAI-1 and severity scores. The mortality rate was 63, 33 and 0% for patients with the 4G/4G, 4G/5G and 5G/5G genotypes, respectively.

CONCLUSIONS

These results demonstrate that the 4G/5G polymorphism of the PAI-1 gene affects the plasma PAI-1 concentration, which could impair fibrinolysis and cause organ failure, and thus the presence of the 4G allele increases the risk of death.

Role of tissue plasminogen activator and plasminogen activator inhibitor polymorphism in myocardial infarction

A case-control association study on 229 Myocardial Infarction (MI) patients and 217 healthy controls was carried out to determine the role of tissue-plasminogen activator (t-PA) (Alu-repeat insertion (I)/deletion (D)) and plasminogen activator inhibitor (PAI-1) (4G/5G insertion/deletion) polymorphisms with MI in the Pakistani population. In MI patients the genotype distribution of the PAI-1 gene was not found to be different when compared with the unaffected controls (P>0.05, χ2=1.03). The risk allele 4G was also not associated with MI (P>0.05, χ2=0.46, odds ratio (OR)=1.1 (95% confidence interval (CI)=0.84-1.43), P>0.05). Similarly, the genotype frequencies of t-PA I/I, I/D and D/D were not different from the unaffected controls (P>0.05, χ2=1.60), and the risk allele "I" was not found to be associated with MI (P>0.05, χ2=1.35, OR=0.86 (95% CI=0.66-1.11), P>0.05). However, when the data were distributed along the lines of gender a significant association of the 4G/4G PAI-1 genotype was observed with only the female MI patients (P<0.05, z-test=2.21). When the combined genotypes of both the polymorphisms were analyzed, a significant association of MI was observed with the homozygous DD/4G4G genotype (P<0.01, z-test=2.61), which was specifically because of the female samples (P=0.01, z-test=2.53). In addition smoking (P<0.001, χ2=13.52, OR=3.45 (95% CI=1.77-6.94)), diabetes (P<0.001, χ2=22.45, OR=8.89 (95% CI=2.96-29.95)), hypertension (OR=7.76 (95% CI=2.88-22.68), P<0.001) family history (P<0.001, χ2=13.72, OR=3.7 (95% CI=1.71-8.18)) and lower HDL levels (P<0.05) were found to be significantly associated with the disease. In conclusion the PAI-1 gene polymorphism was found to have a gender specific role in the female MI patients.

Candidate gene polymorphisms and the 9p21 locus in acute coronary syndromes

It is now widely accepted that the classic environmental risk factors for atherosclerosis only partly explain the incidence of coronary artery disease and the development of acute coronary syndromes. Therefore, genetic factors that vary among human populations seem to be involved in the clinical manifestations of such patients. Substantial data suggest that a significant proportion of genetic polymorphisms involved in endothelial function, inflammation, lipid metabolism, thrombosis and fibrinolysis are often present in patients with acute coronary syndromes. In particular, a common variant on chromosome 9p21 was recently identified to affect the risk of myocardial infarction. Here, we review the progress of candidate gene studies and genome-wide association studies in identifying the genetic bases of complex cardiovascular diseases such as acute coronary syndromes.

Insulin resistance after precocious pubarche: relation to PAI-1-675 4G/5G polymorphism, and opposing influences of prenatal and postnatal weight gain

OBJECTIVE

The common promoter -675 4G/5G insertion/deletion polymorphism (indel) in the plasminogen activator inhibitor-1 (PAI-1) gene has been associated with quantitative components of the metabolic syndrome. We hypothesized that this polymorphism is associated with precocious pubarche (PP), a population known to be at risk for hyperinsulinaemic hyperandrogenism.

DESIGN

A cross-sectional, hospital-based study.

PATIENTS

A total of 115 control and 182 PP Catalan girls and young women.

MEASUREMENTS

Subjects were genotyped for the -675 4G/5G indel in the PAI-1 gene. Insulin resistance and insulin secretion were estimated by the homeostasis model assessment.

RESULTS

Genotype frequencies for the PAI-1-675 4G/5G indel (4G4G, 4G5G and 5G5G) were similar in control and PP subjects (24%vs. 27%, 50%vs. 47%, and 26%vs. 26%, respectively; P = 0.85) and these frequencies were in Hardy-Weinberg equilibrium. The 5G allele, however, was associated with insulin resistance in both postmenarcheal control and PP subjects (P < 0.01 for pooled postmenarcheal subjects, N = 122). The coexistence with the at-risk genotype of both a low birthweight (standard deviation score, SDS < -1.0) and a high body mass index (BMI) at time of the study (SDS > +1.0) resulted in a noteworthy increase (P < 0.001) in insulin resistance.

CONCLUSION

The common promoter -675 4G/5G indel of the PAI-1 gene is not associated with PP but, in Catalan young women, the 5G allele enhances the risk for insulin resistance imposed by the sequence of a low birth weight (LBW) and a high BMI.

Plasminogen activator inhibitor-1 4G4G genotype is associated with myocardial infarction but not with stable coronary artery disease

BACKGROUND

A case control study was conducted to test the hypothesis that plasminogen activator inhibitor type-1 (PAI-1) 4G/5G gene polymorphism confers an increased risk for myocardial infarction (MI) in patients with known coronary atherosclerosis.

METHODS

One hundred fifty-six consecutive patients who presented with acute MI and 111 stable coronary artery disease (SCAD) patients with documented critical coronary artery stenoses were prospectively enrolled. PAI-1 4G/5G gene polymorphism and conventional atherosclerotic risk factors were studied in all patients. PAI-1 4G/5G gene polymorphism was studied in another 281 healthy blood bank donors.

RESULTS

The frequency 4G4G genotype was significantly higher in the MI group as compared to SCAD group (32.7% vs. 15.3%, P = 0.001) while it was not statistically significant between MI and healthy control groups (32.7% vs. 26.0%, P = 0.136). Comparing with healthy controls SCAD group had significantly lower frequency of 4G4G genotype (P = 0.024). In comparison with SCAD group PAI-1 4G/4G genotype, male sex and smoking habits favored to MI in univariate analysis with a P value of less than 0.2. These variables were included in multivariate regression model to estimate the associated risk for MI. PAI-1 4G/4G genotype was the only independent variable (OR 2.67, 95%CI 1.43-4.96, P = 0.002) associated with MI in this regression model. Comparing with healthy control group 4G4G genotype was not associated with MI (OR 1.38, 95%CI 0.90-2.12). However, presence of 4G4G genotype had a protective effect against development of SCAD (OR 0.52, 96%CI 0.29-0.92).

CONCLUSION

Compared to patients with critical coronary stenoses, PAI-1 4G/4G genotype was found to be an independent predictor for development of MI in this population. PAI-1 4G4G genotype have a protective effect against development of high grade stable coronary stenoses.

Parent-of-origin transmission of thrombophilic alleles to intrauterine growth-restricted newborns and transmission-ratio distortion in unaffected newborns

Findings on the role of thrombophilic polymorphisms in adverse pregnancy outcomes, particularly intrauterine growth restriction, are inconsistent. Such inconsistencies may be partly due to two types of effects which have not been considered before with regard to thrombophilic genes: parent-of-origin effects (imprinting) and transmission-ratio distortion effects (allele transmission differing from that expected in unaffected subjects). In this study of infants born at a Canadian hospital (1998-2000), the authors investigated both types of effects. Cases (n = 493) were defined as newborns whose birth weight for gestational age and sex was below the 10th percentile by national standards, and controls (n = 472) as newborns at or above the 10th percentile. Log-linear models were used to analyze the transmission of variant alleles among case- and control-parent trios. A single copy of a common polymorphism, Val34Leu in factor XIII, increased the risk of intrauterine growth restriction approximately 70% when the parent of origin was the father as opposed to the mother (p < 0.05). Among unaffected newborns, transmission of A1298C in the methylenetetrahydrofolate reductase gene (p < 0.005), transmission of the G1691A variant in factor V Leiden (p < 0.002), and transmission of the G20210A variant in the prothrombin (factor II) gene (p < 0.001) occurred significantly less often than expected (transmission-ratio distortion). Affected newborns also inherited the prothrombin G20210A variant significantly less often than expected. These results suggest that these three genes exhibit segregation distortion or reduce gestational survival.

Plasminogen activator inhibitor-1 4G/5G polymorphism and efficacy of reperfusion therapy in acute myocardial infarction

Plasminogen activator inhibitor-1 (PAI-1) plays a central role in the modulation of intravascular thrombosis and thrombolysis. The level of transcription and the plasma level of PAI-1 are in part determined by the 4G/5G polymorphism in the promoter region of the gene. In this study we investigate the effect of 4G/5G polymorphism on the efficacy of reperfusion therapy in acute myocardial infarction (AMI). Two hundred and ninety-three patients were enrolled in two randomized trials comparing stenting plus abciximab with thrombolysis (alteplase alone or alteplase plus abciximab) in AMI. Patients were genotyped for the PAI-1 4G/5G polymorphism with a TaqMan assay. Technetium-99m sestamibi was injected before and 1-2 weeks after reperfusion treatment. Scintigrams were used to calculate the initial perfusion defect, the final infarct size and the salvage index representing the proportion of the initial defect salvaged by reperfusion. An 18-month clinical follow-up was carried out after reperfusion treatment. The distribution of genotypes was as follows: 4G4G in 28.0%, 4G5G in 49.5% and 5G5G in 22.5% of the patients. No significant differences between the three genotypes were detected for the final infarct size (%) of the left ventricle [median (interquartile range); 13.5 (5.0--27.0) for 4G4G patients, 12.0 (5.2--24.6) for 4G5G patients and 16 (7.1--31.2) for 5G5G patients; P=0.36], the salvage index [0.49 (0.25--0.75) in 4G4G patients, 0.47 (0.18--0.73) in 4G5G patients and 0.46 (0.22--0.62) in 5G5G patients; P=0.58] and the mortality 18 months after treatment (8.5% for 4G4G patients, 7.6% for 4G5G patients and 6.1% for 5G5G patients; P=0.85). There was no association in any of the two treatment groups (stenting and thrombolysis) between the 4G/5G genotype and myocardial salvage. The PAI-1 4G/5G polymorphism has no impact on the amount of myocardial salvage achieved by reperfusion with stenting or thrombolysis in patients with AMI.

Thrombophilic Polymorphisms and Intrauterine Growth Restriction

BACKGROUND

The relationship between thrombophilic polymorphisms and intrauterine growth restriction remains unclear. Whereas a subset of these polymorphisms have received some attention, others have not.

METHODS

We conducted a case-control study of 493 cases of intrauterine growth restriction (birthweight less than the 10th percentile for gestational age and sex) and 472 controls (greater than the 10th percentile). We also conducted a family study including approximately 250 case trios (affected newborn, mother, and father) for each studied gene. Plasminogen activator inhibitor-1(PAI-1) 4G/5G and Factor XIII Val134Leu variants were compared between maternal and newborn cases and controls. Relative risks for newborn and maternal PAI-1 and Factor XIII genotypes in case trios were estimated using a log-linear model. Transmission of MTHFR C677T and 1298C haplotypes was analyzed in case trios, and the estimated haplotype distribution compared between cases and controls. Finally, we explored pairwise gene-gene interactions between all measured polymorphisms, including Factor V Leiden G1691A and Prothrombin G20210A.

RESULTS

PAI-1 and Factor XIII polymorphisms were not associated with an increased risk of intrauterine growth restriction in the case-control analysis, and the case-parent analysis showed no newborn or maternal excess genotype relative risk. No excess transmission of the MTHFR haplotypes was observed in case newborns, and the distribution of MTHFR haplotypes was similar between cases and controls. Some results were suggestive of interactions between genes.

CONCLUSIONS

Overall, there seems to be little or no indication that thrombophilic genes, at least individually, have an effect on intrauterine growth restriction.

4G/5G polymorphism of the plasminogen activator inhibitor-1 gene and risk of restenosis after coronary artery stenting

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) has been proposed as a candidate risk factor for restenosis after coronary artery stenting. Transcription, level, and activity of PAI-1 are influenced by the 4G/5G polymorphism in the promoter region of PAI-1 gene. The polymorphism may therefore affect wound-healing processes in injured blood vessels and influence restenosis.

METHODS

In 1850 consecutive patients, angiographic measures of restenosis and the clinical outcome at 30 days and 1 year after stent implantation were evaluated. Angiographic restenosis was defined as > or =50% diameter stenosis determined at follow-up angiography, performed 6 months after stenting. The 4G/5G genotypes were determined with TaqMan technique.

RESULTS

Among the patients, the frequency of the 4G allele was 0.55. Follow-up angiography was done in 84% of the patients. We observed restenosis in 32.5% of 4G/4G carriers, 32.2% of 4G/5G carriers, and 35.7% of 5G/5G carriers (P =.52). The occurrence of a major adverse event (death, myocardial infarction, or target vessel revascularization due to restenosis-induced ischemia) was 5.6% in 4G/4G carriers, 5.3% in 4G/5G carriers, and 4.6% in 5G/5G carriers at 30 days (P =.80), and 24.7% in 4G/4G carriers, 23.0% in 4G/5G carriers, and 26.2% in 5G/5G carriers at 1 year (P =.45).

CONCLUSION

The 4G/5G polymorphism of the PAI-1 gene is not associated with an increased risk of thrombotic and restenotic events after coronary artery stenting.

4G/5G promoter polymorphism of plasminogen activator inhibitor-1, lipid profiles, and ischemic stroke

The 4G allele of common 4G/5G polymorphism in the promoter of the plasminogen activator inhibitor-1 (PAI-1) gene is associated with increased PAI-1 transcription and has been proposed as a candidate genetic risk factor for thrombotic diseases. We investigated the relationship between this polymorphism and lipid profiles and stroke risk. One hundred patients with ischemic stroke and 150 age- and sex-matched control subjects were enrolled. PAI-1 genotype was determined with the use of polymerase chain reaction and restriction-length analysis. Genotype distribution in the stroke group was 40% 4G/4G, 46% 4G/5G, and 14% 5G/5G; in the control group it was 38.7% 4G/4G, 45.3% 4G/5G, and 16% 5G/5G. The allele and genotype frequencies of 4G/5G polymorphism were not different between the stroke and control groups. Control subjects who were homozygous for the 4G allele had significantly lower high-density lipoprotein (HDL) cholesterol levels than did those carrying the 5G allele (51.2 +/- 11.8 vs 58.4 +/- 15.8 mg/dL; P =.002). In the control group, regression analysis revealed a significant contribution of 4G/4G genotype to increased triglyceride (P =.042) and to decreased HDL cholesterol (P <.001) levels. Our findings suggest that PAI-1 4G/5G promoter polymorphism alone is not associated with ischemic stroke. However, this polymorphism influences lipid levels, and the underlying mechanism must be determined.

Lack of association of the plasminogen activator inhibitor-1 4G/5G promoter polymorphism with cardiovascular disease in the elderly

Elevated circulating plasminogen activator inhibitor-1 (PAI-1) may increase risk of cardiovascular disease (CVD). The 4G allele of the 4G/5G PAI-1 promoter polymorphism is associated with higher levels of PAI-1. We examined the association of PAI-1 4G/5G genotype and CVD events in the elderly participants of the Cardiovascular Health Study (CHS). We measured 4G/5G genotype in a nested case-control study within the CHS. Cases included incident angina, myocardial infarction (MI), and stroke. 4G/5G genotype was not found to be associated with markers of fibrinolysis or CVD risk in the selected elderly cohort. There were no differences in genotype frequencies by case-control status (5G/5G frequency 16-22%; chi2P= 0.07). The 5G allele was not associated with incident CVD events when individuals with at least one 5G allele were compared to 4G/4G homozygotes. The presence of at least one 4G allele was likewise not associated with incident CVD when those with 4G/4G and 4G/5G genotypes were compared to 5G/5G homozygotes. Our results suggest that the PAI-1 4G/5G promoter polymorphism is not associated CVD risk factors or incident CVD events in the elderly.

The genetics of atherothrombotic disorders: a clinician's view

The development of coronary artery disease is dependent on the interaction of multiple biochemical pathways that lead to the development of plaque in the arterial wall and ultimately plaque instability, plaque rupture and thrombosis. The latter stages lead to vascular obstruction, tissue death and the final phenotype of myocardial infarction. Hemostasis gene association studies of atherothrombotic disorders have been unrewarding, with largely underpowered studies reporting inconsistent results. Clinical studies such as the Multiple Risk Factor Intervention Trial clearly indicate that clustering of classical risk increases the likelihood of myocardial infarction, and the addition of diabetes mellitus to the risk profile exponentially increases the risk of a vascular event. The development of insulin resistance is considered to be a pivotal event in vascular risk with associated clustering of dysglycemia, hyperinsulinemia, systolic hypertension, raised triglyceride and low high-density lipoprotein cholesterol. Additionally, elevated levels of plasminogen activator inhibitor-1, factor (F)VII, FXII, fibrinogen and tissue plasminogen activator occur with insulin resistance to create an atherothrombotic risk cluster. Heritability studies of insulin resistance and the vascular risk profile demonstrate genetic pleitropy between diabetes and vascular risk, which indicate that common genes have an important role. Increasingly, it is felt that inflammation underpins both diabetes and cardiovascular disease and that the expression of the final phenotype(s) may depend on complex gene-environment interactions with regulatory genes, including those for nuclear transcription factors and RNA-binding proteins. The complexity of coronary artery disease and the risk factor interactions make it unlikely that genetic epidemiology will identify genes involved in these processes without a better understanding of environmental influences.

Genetic variation in coagulation and fibrinolytic proteins and their relation with acute myocardial infarction: a systematic review

BACKGROUND

It is pathophysiologically conceivable that genetic variations in coagulation and fibrinolytic proteins are associated with the risk of myocardial infarction. Methods and Results- We performed a literature search to identify published case-control studies correlating the factor V Leiden or prothrombin G20210A mutations or fibrinogen G-455A or plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphisms with the risk of myocardial infarction. Studies were included only if they used solid diagnostic criteria and complied with published methodological criteria. A common OR with corresponding 95% CI was calculated for the risk of myocardial infarction in a fixed-effect model according to Mantel-Haenszel. The factor V Leiden and prothrombin G20201A mutations did not significantly correlate with myocardial infarction (OR 1.26, 95% CI 0.94 to 1.67, P=0.12 and OR 0.89, 95% CI 0.59 to 1.35, P=0.6, respectively). Inclusion of the studies that investigated young patients (<55 years) made the association significant for factor V Leiden (OR 1.29, 95% CI 1.03 to 1.61, P=0.02). Homozygosity for the fibrinogen -455A allele was significantly associated with a decreased risk of myocardial infarction (OR 0.66, 95% CI 0.44 to 0.99, P=0.04), whereas the PAI-1 4G4G genotype was significantly associated with increased risk (OR 1.20, 95% CI 1.04 to 1.39, P=0.04).

CONCLUSIONS

Associations between these genetic variations and myocardial infarction were weak or absent. In the absence of clinical implications, our results indicate that screening of patients with myocardial infarction for these genetic variations is not warranted.

Regulation of PAI-1 expression by genetic polymorphisms. Impact on atherogenesis

Increased expression of plasminogen activator inhibitor type 1 (PAI-1) is now considered as an independent risk factor for cardiovascular disease. Numerous biochemical factors have been found to regulate the expression of PAI-1 gene and the synthesis of PAI-1 protein. In the recent past, polymorphisms in the PAI-1 gene have been identified and their impact on PAI-1 expression has been characterized. This article will review the current knowledge of these PAI-1 gene polymorphisms (in cell culture epidemiological, and clinical studies) and their role in the development of cardiovascular disease.

Complementary effects of Mediterranean diet and moderate red wine intake on haemostatic cardiovascular risk factors

OBJECTIVES

To compare the effect of alcohol-free Mediterranean-type diet (MD) and high-fat diet (HFD) on plasma concentration of emergent haemostatic cardiovascular risk factors (HCVRF). Also, to test if red wine supplementation modifies HCVRF, independent of diet.

DESIGN, SUBJECTS AND INTERVENTION

Controlled prospective intervention study. Two groups, each of 21 healthy male university students (22+/-3.4 y), received either MD or HFD for 90 days. Between days 30 and 60, both diets were supplemented with 240 ml/day of red wine. Baseline and T30, T60 and T90-day samples were drawn. No drop out from the study was observed.

SETTING

University campus and outpatient nutrition clinic.

RESULTS

Volunteers on HFD at T30 had increases in pro-coagulants fibrinogen (22%), factor VIIc (9%), and factor VIIIc (4%), and decreases in natural anticoagulants antithrombin III (3%), protein C (11%) and protein S (6%) and of 20% in plasminogen activator inhibitor-1. At the same time, individuals on MD had increases in fibrinogen (4%), antithrombin III (5%), protein C (3%), protein S (2.7%), and decreases in factor VIIIc (9%), and plasminogen activator inhibitor-1 (21%). After adjusting by baseline values, MD was associated with lower plasma fibrinogen (P=0.03), factor VIIc (P=0.034) and factor VIIIc (P=0.0057) and with higher levels of protein S (P=0.013). Red wine supplementation, in both diets, resulted in decreased plasma fibrinogen (P=0.001) and factor VIIc (P=0.05), and increased tissue plasminogen activator antigen (P=0.01) and plasminogen activator inhibitor-1 antigen (P=0.0003). Wine consumption was also associated with significantly (P=0.01) divergent effects on antithrombin III: it decreased by 10% in individuals on HFD but increased slightly in those on MD. No effects of diet or wine were detected in plasma protein C and C-reactive protein.

CONCLUSION

MD and moderate consumption of red wine have complementary, mostly beneficial effects on HCVRF.

Genetics of arterial prothrombotic risk states

Coronary artery disease is a leading cause of death worldwide and the largest killer of men and women in the United States. The pathophysiology of myocardial infarction is multifactorial, and numerous physiologic systems converge to dictate the formation of the two fundamental lesions, thrombosis and atherosclerosis. In this review we address genetic aspects of arterial thrombosis and the key thrombotic factors that have been associated with the increased risk for its development. Specifically, we consider components of coagulation, fibrinolysis, and platelet adhesive receptors, and we review the genetic epidemiology and in vitro laboratory data regarding their risk for the acute coronary syndromes. In combination with traditional risk factor assessment, in the near future these inherited markers can be used to manage patients with vascular disease through a better utilization of invasive or expensive diagnostic testing, as well as pharmacologic intervention.

Thrombophilia, polymorphisms, and vascular disease

Thrombophilia traditionally refers to rare inherited defects leading to enhanced coagulation, especially of the venous system. In recent years, a broader search for genetic polymorphisms of prothrombotic genes has been carried out to determine the relative impact on venous and arterial thrombosis. The bulk of evidence is drawn from numerous, often small, heterogeneous, case control association studies, with a variety of end points (deep venous thrombosis, myocardial infarction, or stroke). The data are often conflicting and inconclusive with only factor V Leiden and prothrombin polymorphisms having clear associations with venous thrombosis. Many of the polymorphisms interact with established cardiovascular risk factors, in particular smoking, to increase greatly the risk of a thrombotic episode. Future studies will need to consider the confounding factors of sample size, race, and clinical end points as well gene-environment interactions.

[Genetic risk factors for myocardial infarct]

Interactions of genetic and environmental risk factors influence the susceptibility to coronary artery disease (CAD) and myocardial infarction. In myocardial infarction occurring at young age, genetics of this multifactorial disease may be the leading factor. A number of candidate genes have been implicated in the pathogenesis of CAD and myocardial infarction. Mutations in the DNA sequence (gene polymorphisms) have been identified that appear to play a crucial role in blood pressure regulation, lipid metabolism, endothelial function, in the pathophysiology of coagulation or thrombosis, or in interventional cardiology by interfering with restenosis development. Genetic polymorphisms seem to be clinically important because they not only potentiate the individual risk under certain circumstances, but they also determine safety and effectiveness of commonly prescribed drugs. Understanding the complexity and functional relevance of genetic risk factors will be useful in early detection and treatment of individuals that are exposed to higher risk for myocardial infarction. Thus it is important to include genetic risk factors in the concept of the classical risk factor theory. Potentially in future a genetic risk profile including relevant polymorphisms may be an essential part of the clinicians' knowledge in primary and secondary prevention of coronary artery disease.