Prevalence of resistance against activated protein C resulting from factor V Leiden is significantly increased in myocardial infarction: investigation of 507 patients with myocardial infarction

Acute Myocardial Infarction in Patients with Hereditary Thrombophilia-A Focus on Factor V Leiden and Prothrombin G20210A

Factor V (FV) Leiden and prothrombin G20210A are the most common hereditary thrombophilias. While their role in venous thromboembolism is well known, there are still uncertainties regarding their relationship with arterial thrombotic events, especially coronary ones. Our research, based on an in-depth analysis of the available literature, provides up-to-date information on the relationship between FV Leiden and prothrombin G20210A and acute myocardial infarction. FV Leiden and prothrombin G20210A screening should be implemented only in select cases, such as acute coronary syndrome in young individuals and/or in the absence of traditional cardiovascular risk factors and/or in the absence of significant coronary artery stenosis at angiography. Their identification should be followed by the implementation of optimal control of modifiable traditional cardiovascular risk factors to reduce the risk of recurrent events and genotyping and genetic counseling of all family members of affected cases for proper prophylaxis. An extended dual antiplatelet therapy (DAPT) may be considered, given the lower risk of bleeding under DAPT conferred by FV Leiden.

A System-Wide Investigation and Stratification of the Hemostatic Proteome in Premature Myocardial Infarction

Introduction

Advancing understanding of key factors that determine the magnitude of the hemostatic response may facilitate the identification of individuals at risk of generating an occlusive thrombus as a result of an atherothrombotic event such as an acute Myocardial Infarction (MI). While fibrinogen levels are a recognized risk factor for MI, the association of thrombotic risk with other coagulation proteins is inconsistent. This is likely due to the complex balance of pro- and anticoagulant factors in any individual.

Methods

We compared measured levels of pro- and anticoagulant proteins in plasma from 162 patients who suffered an MI at an early age (MI <50 y) and 186 age- and gender-matched healthy controls with no history of CAD. We then used the measurements from these individuals as inputs for an established mathematical model to investigate how small variations in hemostatic factors affect the overall amplitude of the hemostatic response and to identify differential key drivers of the hemostatic response in male and female patients and controls.

Results

Plasma from the MI patients contained significantly higher levels of Tissue Factor (P = 0.007), the components of the tenase (FIX and FVIII; P < 0.0001 for both) and the prothrombinase complexes (FX; P = 0.003), and lower levels of Tissue Factor Pathway Inhibitor (TFPI; P = 0.033) than controls. The mathematical model, which generates time-dependent predictions describing the depletion, activation, and interaction of the main procoagulant factors and inhibitors, identified different patterns of hemostatic response between MI patients and controls, and additionally, between males and females. Whereas, in males, TF, FVIII, FIX, and the inhibitor TFPI contribute to the differences seen between case and controls, and in females, FII, FVIII, and FIX had the greatest influence on the generation of thrombin. We additionally show that further donor stratification may be possible according to the predicted donor response to anticoagulant therapy.

Conclusions

We suggest that modeling could be of value in enhancing our prediction of risk of premature MI, recurrent risk, and therapeutic efficacy.

Genetic polymorphisms and the risk of myocardial infarction in patients under 45 years of age

This study investigates the potential role of 17 chosen polymorphisms in 15 candidate genes and the risk of myocardial infarction in patients under 45 years of age. The study consists of 271 patients with myocardial infarction and 141 controls. The analysis of genetic polymorphisms was performed using the PCR–RFLP method. Of the chosen polymorphisms, two (Leu125Val PECAM1 and A1/A2 FVII) are related to myocardial infarction and two (C677T MTHFR and 5A/6A MMP3) to advanced stenosis in arterial vessels (> 75%). We also found that the frequency of some combinations among the analyzed genes and environmental factors varied between the patient and control groups.

The impact of blood coagulability on atherosclerosis and cardiovascular disease

Although the link between blood coagulation and atherogenesis has been long postulated, only recently, and through the extensive work on transgenic mice, crossbred on an atherogenic background, has the direction of this interaction become visible. In general, hypercoagulability in mice tends to increase atherosclerosis, whereas hypocoagulability reduces the atherosclerotic burden, depending on the mouse model used. The information on a direct relationship between coagulation and atherosclerosis in humans, however, is not that clear. Almost all coagulation proteins, including tissue factor, are found in atherosclerotic lesions in humans. In addition to producing local fibrin, a matrix for cell growth, serine proteases such as thrombin may be very important in cell signaling processes, acting through the activation of protease-activated receptors (PARs). Activation of PARs on vascular cells drives many complex processes involved in the development and progression of atherosclerosis, including inflammation, angiogenesis, and cell proliferation. Although current imaging techniques do not allow for a detailed analysis of atherosclerotic lesion phenotype, hypercoagulability, defined either by gene defects of coagulation proteins or elevated levels of circulating markers of activated coagulation, has been linked to atherosclerosis-related ischemic arterial disease. New, high-resolution imaging techniques and sensitive markers of activated coagulation are needed in order to study a causal contribution of hypercoagulability to the pathophysiology of atherosclerosis. Novel selective inhibitors of coagulation enzymes potentially have vascular effects, including inhibition of atherogenesis through attenuation of inflammatory pathways. Therefore, we propose that studying the long-term vascular side effects of this novel class of oral anticoagulants should become a clinical research priority.

Life-threatening aortic thrombosis in a trauma patient homozygous for factor V Leiden mutation: Case report

We report a case of near fatal aortic thrombosis in a trauma patient homozygous for mutation of Factor V Leiden. He responded well to vascular surgery and intensive care unit management and was discharged successfully from the hospital one month later.

Thrombophilia and the risk of thromboembolic events in women on oral contraceptives and hormone replacement therapy

Thrombophilia contributes to the risk of thrombosis in women using female hormones. The objective of the present study was to evaluate the prevalence of thrombophilia in women with thromboembolic events (TEEs) using oral contraceptives or hormone replacement therapy (HRT) and assess the contribution of a family history and the duration of hormone use in predicting thrombosis. A retrospective analysis was performed of the case records of women who developed a TEE while on oral contraceptives or HRT and were referred for thrombophilia evaluation over a 4-year period. Among 85 women who developed a TEE while on oral contraceptives or HRT, 65 had at least one additional thrombophilia risk factor. Of the 85 cases, 23 tested positive for more than two thrombophilias, 16 had factor V Leiden, five had the prothrombin gene G20210A polymorphism, 26 had antiphospholipid antibodies, 10 had elevated homocysteine, four had protein C deficiency, and seven had protein S deficiency. There were 64 TEE: 16 pulmonary emboli, 17 cerebrovascular events, 11 intra-abdominal thromboses, 13 deep venous thromboses, five cases of superficial thrombophlebitis, and two retinal vein thromboses. Of the 65 women, 37% had a positive family history of thrombosis. Approximately half of the women had been taking oral contraceptives or HRT for more than 1 year. There is a high prevalence of thrombophilia in women who developed a TEE while using oral contraceptives or HRT for more than 1 year. Family and personal history of thrombosis should be carefully evaluated in all women before initiating or continuing oral contraceptives or HRT, and a positive history may warrant a thrombophilia screening.

Factor V Leiden and the risk of venous thrombosis, myocardial infarction, and stroke: a case-control study in Venezuela

The most common genetic defect associated with deep vein thrombosis (DVT) is a mutation in the Factor V gene (G1691A), known as Factor V Leiden (FVL). We investigated the genotypes for FVL in 571 individuals in Venezuela: 208 patients with DVT, 175 patients with acute myocardial infarction, 54 patients with stroke, and 134 control subjects. Our results showed in the population analyzed here that the FVL was associated with a fourfold increase in the risk for DVT (odds ratio, 4.24; 95% confidence interval, 1.35-14.79); particularly, women carriers showed a 6.5-fold increase in the risk for DVT. No relation was observed between the presence of FVL and the risk for acute myocardial infarction or stroke. In conclusion, a clear association between the FVL mutation and DVT was observed in the population analyzed in Venezuela. These results are in agreement with those found in other populations with different ethnic backgrounds.

Polymorphisms in coagulation factors and the risk of recurrent cardiovascular events in men after a first myocardial infarction

BACKGROUND

The aim of this study was to examine whether genetic predisposition to high levels of coagulation factors influences the risk of developing fatal and non-fatal arterial cardiovascular events in men with a first myocardial infarction (MI).

METHODS

We performed a cohort study among 542 MI patients with a mean age of 56 years (range 32-70 years) at the time of the event. All of the men had a first MI between 1990 and 1996 and were followed until 1 September 2004. DNA was analyzed for polymorphisms of fibrinogen, prothrombin (factor II), factor V, factor VII and plasminogen activator inhibitor type 1, all of which are associated with gain of function of the protein. We collected information from hospital files and general practitioners on the occurrence of major arterial events.

RESULTS

In total, 254 major arterial cardiovascular events occurred during a median follow-up period of 11 years (range 0.2-15 years). The point estimates of the relative rates (RRs) of these events for the variant genotypes were all between 0.7 and 1.1 except for the prothrombin 20210A mutation: RR 1.8 (95% confidence interval 0.8-4.1).

CONCLUSION

These findings suggest that there is no association between coagulation factor polymorphisms, previously associated with plasma levels, and the risk of recurrent cardiovascular events.

Activated protein C resistance and factor V Leiden: a review

CONTEXT

Factor V Leiden (FVL) is the most common heritable cause of venous thrombosis. It is caused by a single nucleotide substitution resulting in an R506Q missense mutation, resulting in factor V resistance to activated protein C (APC) inactivation. Carriers of FVL have an increased susceptibility to venous thrombosis, which is further increased in the presence of other genetic or environmental risk factors.

OBJECTIVE

To review the biology, clinical findings, laboratory detection methods, and screening recommendations for patients with the FVL mutation.

DATA SOURCES

PubMed review of published literature and online information.

CONCLUSIONS

FVL remains an important heritable cause of hypercoagulability since its discovery more than 10 years ago. Clinical suspicion should be high in cases of unexplained venous thrombosis. APC resistance and FVL mutation can be diagnosed with high sensitivity and specificity with use of clotting time-based functional assays and genetic assays, respectively, allowing for evidence-guided clinical decision making regarding the benefit of long-term anticoagulation.

Inherited Thrombophilia in Arterial Disease: A Selective Review

Thrombophilia may be defined as an acquired or congenital abnormality of hemostasis predisposing to thrombosis. Because arterial thrombosis is usually linked with classical risk factors such as smoking, hypertension, dyslipidemia, or diabetes, a thrombophilia workup is usually not considered in case of arterial thrombosis. The most accepted inherited hemostatic abnormalities associated with venous thromboembolism are factor V Leiden (FVL) and factor II (FII) G20210A mutations, as well as deficiencies in antithrombin (AT), protein C (PC), and protein S (PS). This review focuses on the link between these abnormalities and arterial thrombosis. Overall, the association between these genetic disorders and the three main arterial complications (myocardial infarction [MI], ischemic stroke [IS], and peripheral arterial disease [PAD]) is modest. Routine screening for these disorders is therefore not warranted in most cases of arterial complications. However, when such an arterial event occurs in a young person, inherited abnormalities of hemostasis seem to play a role, particularly when associated with smoking or oral contraceptive use. These abnormalities also seem to play a role in the risk of premature occlusion after revascularization procedures. Therefore thrombophilia tests may be informative in a very restricted population with arterial events. Anticoagulants rather than antiplatelet therapy may be preferable for these patients, although this remains to be proven.

Acute myocardial infarction following an arthropod bite: is hereditary thrombophilia a contributing factor?

Acute myocardial infarction (AMI) due to arthropod envenomation has rarely been reported in the literature. In the present report, we describe two cases who developed AMI following an arthropod bite. Coronary angiograms revealed normal coronary arteries in both patients. Both events were probably secondary to coronary artery thrombosis and/or coronary artery vasospasm. Both patients were subsequently found to be heterozygous for prothrombin mutation (G20210A). As a result, we recommend ruling out the possibility of hereditary thrombophilias in young patients with AMI developing after an arthropod bite.

Seven haemostatic gene polymorphisms in coronary disease: meta-analysis of 66,155 cases and 91,307 controls

BACKGROUND

Variants of certain haemostatic genes (such as that encoding factor V Leiden) are involved in the development of venous thrombosis, but studies of such variants in coronary disease have reported apparently conflicting results. We did meta-analyses on seven such haemostatic genetic variants for which the available evidence on each comprises at least 5000 coronary disease cases and at least 5000 controls.

METHODS

Meta-analyses were done of 191 studies in relation to factor V G1691A (ie, factor V Leiden), factor VII G10976A, prothrombin G20210A, plasminogen activator inhibitor-1 (PAI-1) [-675] 4G/5G, and three platelet glycoprotein (GP) receptor variants (GPIa C807T, GPIbalpha T[-5]C, GPIIIa C1565T), involving a total of 66 155 coronary disease cases and 91 307 controls. We explored potential sources of heterogeneity.

FINDINGS

In a combined analysis of all studies, the per-allele relative risks (RR) for coronary disease of factor V 1691A and of prothrombin 20210A were 1.17 (95% CI 1.08-1.28) and 1.31 (1.12-1.52), respectively. Combined analyses of studies of the PAI-1 [-675] 4G variant yielded a per-allele relative risk for coronary disease of 1.06 (1.02-1.10), but there was an indication of publication bias in these studies. Combined analyses of the factor VII 10976A, GPIa 807T, GPIbalpha [-5]C, and GPIIIa 1565T variants showed no significant overall associations with coronary disease, yielding per-allele RRs of 0.97 (0.91-1.04), 1.02 (0.97-1.08), 1.05 (0.96-1.13), and 1.03 (0.98-1.07), respectively.

INTERPRETATION

The 1691A variant of the factor V gene and the 20210A variant of the prothrombin gene, both of which increase circulating thrombin generation, might each be moderately associated with the risk of coronary disease. Further studies are merited to assess these associations in greater detail (including any gene-gene and gene-environment interactions) and to determine any implications with regard to potential therapies designed to reverse patients' prothrombotic phenotype, such as selective plasma factor V or factor Xa inhibition.

Sequence variations within the genes related to hemostatic imbalance and their impact on coronary artery disease in Turkish population

Coronary artery disease (CAD) is reported to be associated with some genetic risk factors. Since identification of genetic risk factors for CAD in different ethnic groups is important for the development of new intervention and prevention programs, we investigated the association between the R353Q and -323ins10 polymorphisms in Factor VII gene, C677T mutation in MTHFR, Factor V Leiden and PT G20210A mutations and CAD in Turkish population. The promoter region of the PAI-1 gene was also screened by SSCA (single-stranded conformation analysis) using specifically designed primers. 137 CAD patients with early onset documented by coronary angiography and 41 individuals who had no significant coronary stenosis by angiography as control group were screened for the identification of the polymorphisms. In conclusion, Factor V Leiden was found to be an independent genetic risk factor for CAD in Turkish population. Combined risk assessment indicated that the coexistence of two other inherited thrombophilia markers, namely MTHFR C677T and PT G20210A with Factor V Leiden may increase the risk of the development of the disease in this population. The results of the present study show that there is no statistically significant association between the two polymorphisms in Factor VII gene, MTHFR C677T polymorphism, PT G20210A polymorphism, 4G/5G polymorphism of PAI-1 and CAD in Turkish population.

Multi-chamber intracardiac thrombi associated with activated protein C resistance in a patient with dilated cardiomyopathy

Combined activated protein C resistance and dilated cardiomyopathy result in a multiplicative effect on thrombosis risk. However, it is not known that whether there is an association with activated protein C resistance and dilated cardiomyopathy. We present a 18-year-old patient with dilated cardiomyopathy, who exhibited multi-chamber intracardiac thrombi on transthoracic echocardiography associated with activated protein C resistance. Our cases emphasizes that patients with cardiac thrombosis before adulthood should be screened for an underlying coagulation abnormality besides underlying cardiac disorders.

A new PCR-SSP typing method for six single-nucleotide polymorphisms impairing the blood-clotting cascade as well as T-cell stimulation

Single-nucleotide polymorphisms (SNPs) within the genes of factor V (FV) (G1691A; exon 10), prothrombin (FII) (G20210A; 3'untranslated - region) and methylenetetrahydrofolate reductase (MTHFR) (C677T; exon 4) are associated with hypercoagulability, and systematic screening of individuals being at higher risk of thrombosis has been suggested. SNPs in the 2q33 region within the genes of CD28 (+17T/C; intron 3) and CTLA4 (-318C/T; promoter and +49A/G; exon 1) are likely to affect T-cell proliferation and antigen presentation signaling, which may lead to altered sensitivity of allograft or self-tissue recognition and affect the incidence of autoimmune diseases. We developed primers that allow specific amplification of these six SNPs at test conditions identical with those used for HLA typing with the CTS PCR-SSP reagents. One hundred ninety-six healthy German Caucasian individuals were tested for the six SNPs. The genotype frequencies for all SNPs were in Hardy-Weinberg equilibrium. There was no significant difference in the distribution of genotypes when compared to other published studies in which these SNPs were tested. The described PCR-SSP method can be used to screen large numbers of patients for these SNPs.

Homozygous factor V Leiden mutation in two siblings presenting with acute myocardial infarction: a rare cause of myocardial infarction in the young

Although factor V Leiden mutation, is the most common established genetic risk factor for venous thrombosis, its effect on the development of myocardial infarction remains unclear. We describe a family case of homozygous factor V Leiden mutation in two siblings presenting with acute myocardial infarction as a rare cause of myocardial infarction in the young.

Factor V Leiden and its effect on children with cardiac pathology

Factor V Leiden thrombophilia, formed by a genetic mutation, slows the body's anticoagulation response to clot formation. First described in 1994, factor V Leiden mutation has been identified as a contributing risk factor for venous thromboembolism. Although venous thromboembolism is considered rare in the pediatric population, Factor V Leiden has implications for certain at-risk pediatric patients.