Factor V Leiden and myocardial infarction: a case,review of the literature with a meta-analysis

Mutation in blood coagulation factor V Leiden is the most frequently genetic polymorphism implied in venous thrombosis. A 57 year old man was hospitalised for acute myocardial infarction (MI). An emergency coronary angiography was performed, and no significant stenosis was observed. The haematologic check-up showed an heterozygous Leiden mutation of factor V. We report all publications about the relation between factor V Leiden and coronary thrombosis, and we performed a meta-analysis. We analysed the relation in general population and in subgroups, such as, younger and older, and patient with or without coronary stenosis. In global population, the meta-analysis did not found significant association between Factor V Leiden and myocardial infarction (OR = 1.25; IC = 0.97-1.58). In contrast, in patients less than < 55 years old after MI, Factor V Leiden prevalence was significantly higher than in control group (OR = 1.48; IC = 1.05-2.08). In addition, after MI without significant coronary stenosis Factor V Leiden prevalence was significantly higher than in normal patients (OR = 2.84; IC = 1.46-5.51). After MI, in patients without significant coronary stenosis, Factor V Leiden prevalence was significantly higher than in patients with significant coronary stenosis (OR = 3.26; IC = 1.67-6.36). Our study suggests that Factor V Leiden could be search after MI in young subjects and/or without significant stenosis.     

Incidence of Factor V Leiden in Patients with Acute Myocardial Infarction

The genetic defect of coagulation factor V known as factor V Leiden produces a resistance to degradation by activated protein C (APC) and increases the risk of venous thromboembolism. The data on arterial thrombosis associated with APC resistance are still not clearly defined. We conducted a study in patients presenting with acute myocardial infarction (MI) to assess whether factor V Leiden increases the risk of arterial thrombosis. We studied 109 patients who had a diagnosis of acute MI (69 males and 40 females, aged 25–91 years), and 112 controls. The study population was identified by characteristic ECG changes and elevation of serum CK-MB, whereas the control subjects were anonymous healthy blood donors with no known history of coronary artery disease. Blood samples from the patients and controls were analyzed for the factor V Leiden mutation by DNA analysis, using the polymerase chain reaction. Heterozygous factor V Leiden mutation was found in 9 of 109 (8%) MI patients and 5 of 112 (4%) control subjects (P = .42). In conclusion, this study shows no evidence of an association between factor V Leiden and acute MI.     

Levels of intrinsic coagulation factors and the risk of myocardial infarction among men: Opposite and synergistic effects of factors XI and XII

The role of the intrinsic coagulation system on the risk of myocardial infarction is unclear. In the Study of Myocardial Infarctions Leiden (SMILE) that included 560 men younger than age 70 with a first myocardial infarction and 646 control subjects, we investigated the risk of myocardial infarction for levels of factor XI (factor XIc) and factor XII (factor XIIc). Furthermore, the risks for factor VIII activity (factor VIIIc) and factor IX activity (factor IXc) were assessed. Factor XIc was 113.0% in patients compared with 109.8% in control subjects (difference, 3.2%; 95% CI, 1.1%-5.4%). The risk of myocardial infarction adjusted for age for men in the highest quintile compared with those in the lowest quintile was 1.8-fold increased (ORadj, 1.8; 95% CI, 1.2-2.7). In contrast, factor XIIc among patients with myocardial infarction was lower than in control subjects, respectively, 93.0% and 98.6% (difference, 5.6%; 95% CI, 3.3%-7.9%). The odds ratio of myocardial infarction for men in the highest quintile versus those in the lowest quintile was 0.4 (ORadj, 0.4; 95% CI, 0.2-0.5). The highest risk was found among men with both high factor XIc and low factor XIIc (analyses in tertiles: ORadj, 6.4; 95% CI, 2.2-18.0). Factor VIIIc increased the risk of myocardial infarction although not dose dependently. Factor IXc increased the risk; odds ratio of myocardial infarction for men in the highest quintile versus those in the lowest quintile was 3.2 (ORadj, 3.2; 95% CI, 2.0-5.1). Thus, factors XIc and XIIc have opposite and synergistic effects on the risk of myocardial infarction in men; factor VIIIc and factor IXc increase the risk.     

Genetic risk factors in acute coronary disease

OBJECTIVE: We investigate whether each of the following: HPA-1, Factor V Leiden, prothrombin gene variant and the methylene tetrahydrofolate reductase gene (MTHFR) mutation, are risk factors for acute coronary disease in Portuguese patients. MATERIAL AND METHODS: 100 blood donors and 52 patients with an established diagnosis of myocardial infarction or unstable angina were evaluated for genetic risk factors, by determining HPA-1 genotype, Factor V Leiden, Prothrombin 20210 variant and MTHFR mutation. RESULTS: We found a prevalence of 2.0% for Factor V Leiden, 5.0% for the Prothrombin 20210 variant and 66% for the MTHFR mutation in blood donors. These values are similar to those found in the patients (1.9, 3.8 and 58%, respectively). We found that 28/100 controls had the PI(A2) polymorphism, a frequency statistically different from that in the patients (23/52). This difference was even more pronounced in patients less than 60 years old (27/96 vs. 13/24). CONCLUSION: Factor V Leiden, Prothrombin 20210 variant and MTHFR mutation do not seem to represent risk factors for acute coronary disease. However, the PI(A2) polymorphism could have a role in the pathogenesis of this disease. The presence of multiple genetic factors, more than single ones, could influence the development and outcome of myocardial infarction and unstable angina. Larger studies are needed in order to have a better insight into the pathophysiological mechanisms of this disease, along with its prevention and the development of new treatments.     

The prevalence of factor V Leiden as a risk factor for venous thromboembolism in the population of North-Western Greece.

BACKGROUND: Many predisposing factors have been associated with the development of venous thromboembolism. Recently, Factor V Leiden has been described as a common genetic risk factor. The geographic distribution of this genetic abnormality in the general population greatly varies. The prevalence of the Factor V Leiden mutation in Europe is high, particularly in Greece, where according to some authors it is especially high. The purpose of this study was to estimate the prevalence of the Factor V Leiden mutation in patients presenting with at least one episode of venous thromboembolism and to compare it with that of the general population. METHODS: Blood samples were drawn from 388 subjects. 240 healthy blood donors (controls) and 148 unselected patients with a history of one or more episodes of venous thrombosis. DNA analysis was performed using the polymerase chain reaction to amplify the factor V gene exon 10, and to detect the Factor V Leiden point mutation. RESULTS: DNA analysis revealed Factor V Leiden mutations in eight (3.3%) control subjects (seven heterozygous and one homozygous) and in twenty-four (16.2%) patients, (twenty-two heterozygous and two homozygous). The difference between the two groups is statistically significant (p<0.0001; chi2 test). CONCLUSIONS: The prevalence of the Factor V Leiden mutation in the general population of North-Western Greece is 3.3%, which is within the same range as that reported for other European countries. The Factor V Leiden mutation is one of the most important predisposing genetic factors in the development of venous thrombosis and was present in 16.2% of our patients.     

Prothrombotic coagulation defects and cardiovascular risk factors in young women with acute myocardial infarction

We investigated the effect of prothrombotic coagulation defects in combination with smoking and other conventional risk factors on the risk of myocardial infarction in young women. In 217 women with a first myocardial infarction before the age of 50 years and 763 healthy control women from a population-based case-control study, factor V Leiden and prothrombin 20210A status were determined. Data on major cardiovascular risk factors and oral contraceptive use were combined with the presence or absence of these prothrombotic mutations, and compared between patients and controls. The overall odds ratio for myocardial infarction in the presence of a coagulation defect was 1.1 [95% confidence interval (CI) 0.6-1.9]. The combination of a prothrombotic mutation and current smoking increased the risk of myocardial infarction 12-fold (95% CI 5.7-27) compared with non-smokers without a coagulation defect. Among women who smoked cigarettes, factor V Leiden presence versus absence increased the risk of myocardial infarction by 2.0 (95% CI 0.9-4.6), and prothrombin 20210A presence versus absence had an odds ratio of 1.0 (95% CI 0.3-3.5). We conclude that factor V Leiden and prothrombin 20210A do not add substantially to the overall risk of myocardial infarction in young women. However, in women who smoke, the presence of factor V Leiden increased the risk of myocardial infarction twofold.     

Coagulation factors II, V, VII, and X, prothrombin gene 20210G-->A transition, and factor V Leiden in coronary artery disease: high factor V clotting activity is an independent risk factor for myocardial infarction

Increased levels of hemostatic factors and genetic mutations of proteins involved in coagulation may play a role in the pathogenesis of coronary artery disease. We investigated clotting activity of factors II (FII:C), V (FV:C), VII (FVII:C), and X (FX:C), the prothrombin gene 20210G-->A transition, and the factor V Leiden mutation in 200 survivors of myocardial infarction and in 100 healthy controls. FV:C (P<0.0001) and FVII:C (P<0.0001) were found to be independent risk factors for myocardial infarction. High FV:C or high FVII:C combined with smoking or arterial hypertension increased the relative risk for myocardial infarction up to 50-fold. One of 177 patients (0.6%) and 4 of 89 controls (4.5%) had the prothrombin 20210 AG genotype. Eleven of 177 patients (6.2%) and 6 of 89 controls (6.7%) were heterozygous for the factor V Leiden mutation. No homozygous carrier for these mutations was found. Neither the prothrombin gene 20210G-->A transition (odds ratio [OR], 0.1; 95% confidence interval [CI], 0.01 to 1.1) nor the factor V Leiden mutation (OR, 1.0; 95% CI, 0.4 to 2.8) were associated with an increased relative risk for myocardial infarction. In conclusion, our data indicate that neither the prothrombin gene 20210G-->A transition nor the factor V Leiden mutation are risk factors for myocardial infarction. High FVII:C was confirmed to be an independent risk factor for myocardial infarction. Moreover, we describe for the first time that high FV:C is an independent risk factor for myocardial infarction.     

Factor V Leiden mutation and its relation to left atrial thrombus in chronic nonrheumatic atrial fibrillation

The genetic defect of coagulation factor V, known as factor V Leiden, produces a resistance to degradation by activated protein C and increased venous thrombosis. However, the role of factor V Leiden in the formation of left atrial thrombus with nonrheumatic atrial fibrillation has not been studied. We investigated whether factor V Leiden is a risk factor for left atrial thrombus in patients with nonrheumatic atrial fibrillation. We analyzed clinical, echocardiographic, and biochemical data in 105 consecutive patients with nonrheumatic atrial fibrillation. These patients were divided into two groups: group A (n = 37) with left atrial thrombus and group B (n = 68) without left atrial thrombus. The study also included 42 control subjects. Left atrial thrombus was investigated by using both transthoracic echocardiography and transesophageal echocardiography. Blood samples from the patients and controls were analyzed for the factor V Leiden mutation by DNA analysis, using the polymerase chain reaction. There was no significant difference in the prevalence of factor V Leiden between the patients and control subjects. The prevalence of factor V Leiden mutation was 8.1% (3/37) in patients with left atrial thrombus, and 8.8% (6/68) in patients without left atrial thrombus. The prevalence of factor V Leiden was 7.1% (3/42) in control subjects. The prevalance of factor V Leiden was 10% (2/20) in patients with spontaneous echo contrast and 8% (7/85) in patients without spontaneous echo contrast. Multivariate analyses showed that left ventricular ejection fraction was an independent predictor of left atrial thrombus. Factor V Leiden mutation is not a risk factor for left atrial thrombus formation and spontaneous echo contrast in patients with nonrheumatic atrial fibrillation.     

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.     

Thrombophilia.

Thrombophilia is now considered a multicausal disease, with an interplay of acquired and genetic risk factors. Recent studies have shown that patients with the 20210 A prothrombin mutation display remarkably similar characteristics compared with patients with Factor V Leiden mutation. It is evident that neither the Factor V Leiden mutation nor the 20210 A prothrombin mutation is a major risk factor for myocardial infarction or stroke, unless accompanied by other classical risk factors, including diabetes mellitus, hypertension and smoking. Finally, the homozygous form of the thermolabile methylenetetrahydrofolate reductase gene, although leading to elevated homocysteine levels, seems not to represent a genetic risk factor for venous thrombosis.     

Raised factor VIII is associated with coronary thrombotic events

Coagulation is triggered during the onset of myocardial infarction, resulting in vascular occlusion. However, a causal role for individual haemostatic factors in the development of thrombotic occlusion is not established. Three cases (all relatively young women) are reported of raised factor VIII associated with myocardial infarction. Two patients presented acutely with myocardial infarction at a relatively young age with no preceding history of angina. The other patient had had venous thrombosis when young and activated protein C resistance (APCR), without the presence of factor V Leiden. A functional relation exists between APCR and factor VIII; therefore, raised factor VIII may contribute to APCR and the increased thrombotic risk in patients without factor V Leiden. Factor VIII is an important risk factor for atherothrombotic events, including sudden death, in patients with vascular disease. These cases support the association of raised factor VIII with acute thrombotic events, even in patients without significant underlying atheromatous disease.

Keywords: factor VIII;  thrombosis;  myocardial infarction;  activated protein C resistance     

Methylenetetrahydrofolate reductase gene polymorphism and risk of premature myocardial infarction

BACKGROUND: Elevated plasma homocysteine level is an independent risk factor for cardiovascular disease. A common mutation (nucleotid 677C-T) in the gene coding for methylenetetrahydrofolate reductase (MTHFR) has been reported to reduce the enzymatic activity of MTHFR and is associated with elevated plasma levels of homocysteine, especially in subjects with low folate intake. HYPOTHESIS: Methylenetetrahydrofolate reductase T/T genotype may be a risk factor for premature MI in Turkish population who are known to have low folate levels. METHODS: The study group was comprised of 96 men (aged <45 years) with premature myocardial infarction (MI) and 100 age- and gender-matched controls who had no history or clinical evidence of coronary artery disease (CAD) and/or MI. DNA was extracted from peripheral blood and genotypes were determined by polymerase chain reaction, restriction mapping with HinfI, and gel electrophoresis. Conventional risk factors for CAD were prospectively documented. RESULTS: Allele and genotype frequencies among cases and control subjects were compatible with Hardy-Weinberg equilibrium. The frequencies of T/T, C/T, and C/C genotypes among patients with MI and control subjects were 15.6, 40.6, and 43.8%, and 5, 35, and 60%, respectively. Multivariate analyses identified smoking, MTHFR C/T polymorphism, diabetes mellitus, family history of CAD, and hypertension as the independent predictors of premature MI. Defining patients with non-T/T genotype (C/C and C/T combined) as reference, the relative risk of MI for subjects with T/T genotype was 5.94 (95% confidence interval: 1.96-18.02, p = 0.0016). CONCLUSIONS: Our findings suggest that C677T transition in the MTHFR gene may be a risk factor for premature MI in Turkish men.     

Prothrombin 20210GA and factor V Leiden mutations in patients less than 55 years old with myocardial infarction

Several studies claim that prothrombin 20210GA and factor V Leiden mutations are related to arterial thrombosis. We investigated the frequencies of these mutations and their significance in the development of early atherosclerosis in acute myocardial infarction (AMI) patients younger than 55 years of age. We investigated 96 patients with AMI and 77 control subjects. The diagnosis of AMI was established by typical chest pain and ST elevations on the presentation electrocardiogram and characteristic cardiac enzyme elevations. None of the control subjects had evidence of cardiovascular disease. DNA samples were isolated from all subjects and prothrombin 20210GA and factor V Leiden mutations were determined by the RealTime PCR technique with the aid of a Light Cycler device. The prevalence of factor V Leiden mutation was 6.3% and 5.2% in the patient and control groups, respectively (OR 0.6 [95% CI 0.1- 3.9], P = 0.6), whereas the prevalence of prothrombin G20210A mutation was 4.2% and 2.6% in the patient and control groups, respectively (OR 2.8 [95% CI 0.2 - 32.2], P = 0.4). None of the patients had both mutations. Prothrombin 20210GA and factor V Leiden mutations are not significant risk factors for the development of myocardial infarction in patients less than 55 years old in Southern Turkey.     

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

Background

A point mutation in the gene encoding coagulation factor V is a cause of resistance against activated protein C. The presence of factor V Leiden is linked to 50% of congenital defects causing venous thrombosis. Its relationship to arterial thrombosis, particularly to myocardial infarction, has not been defined. Therefore, we performed a study on the role of factor V Leiden in patients with myocardial infarction. The study was carried out in Bavarians of German origin, a relatively homogeneous population.

Methods and results

The study group consisted of 507 patients with documented myocardial infarction (77.5% (393/507) men, 22.5% (114/507) women), with a mean age of 56.1 (range 18--86) years. Strict criteria for patient selection and highly sensitive and specific functional tests for factor V Leiden were used. In addition, all patients with pathological test results were genotyped. The prevalence of factor V Leiden in patients with myocardial infarction was 8.7% (44/507), a significant increase in the prevalence of this mutation compared with the control group (3.7%, P = .0025). The odds ratio was 2.46 (95% CI 1.35-4.50).

Conclusions

A significantly increased prevalence of factor V Leiden in patients with documented myocardial infarction was seen. Patients with this mutation appear to have a predisposition for myocardial infarction.     

Factor V Leiden and its relation to left ventricular thrombus in acute myocardial infarction

OBJECTIVE: The genetic defect of coagulation factor V, known as factor V Leiden, produces a resistance to degradation by activated protein C (APC) and increases the risk of venous thrombosis. However, the role of factor V Leiden in the formation of left ventricular (LV) thrombus has not been studied. We investigated whether factor V Leiden is a risk factor for LV thrombus in patients with acute myocardial infarction (AMI). METHODS and RESULTS: We have analyzed clinical, echocardiographic and biochemical data in 135 consecutive patients (aged 58 +/- 13 years; 31 women) with first anterior AMI. Two-dimensional echocardiographic examination was performed on days 1, 3, 7, 15 and 30; LV thrombus was detected in 33 (24.4%) of 135 patients with AMI. The study also included 95 control subjects. Healthy age and sex-matched subjects without a personal or family history of ischaemic heart disease, stroke or thromboembolic disease served as a control group. Blood samples from the patients and controls were analyzed for the factor V Leiden mutation by DNA analysis, using the polymerase chain reaction. In addition, concentrations of fibrinogen, von Willebrand factor (vWF), tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and D-dimer were measured in 135 patients. There was no significant difference in the prevalence of factor V Leiden between patients and control subjects. The prevalence of the factor V mutation was 9% (3/33) in patients with thrombus, and 7.7% (8/103) in patients without thrombus. The prevalence of factor V Leiden was 7.3% (7/95) in control subjects. No significant differences in plasma fibrinogen (480 +/- 195 vs. 444 +/- 179 mg/dl, p = 0.6), D-dimer (471 +/- 256 vs. 497 +/- 293 ng/dl, p = 0.7), vWF (112 +/- 18 vs. 103 +/- 15%, p=0.5), PAI-1 (26.7+/- 9.8 vs. 28.1 +/- 10.2 ng/dl, p = 0.6), and t-PA (19.8 +/- 8.7 vs. 17.2 +/- 9.1 ng/dl, p = 0.7), levels are found in patients with LV thrombus when compared with those without LV thrombus. Multivariate analyses showed that peak creatine kinase level (p = 0.002) and LV wall motion score index (p = 0.003) were independent predictors of LV thrombus formation. CONCLUSION: Factor V Leiden mutation is not a risk factor for LV thrombus formation in patients with AMI.     

Factor V Leiden mutation in cerebrovascular disease.

Several studies indicate a high prevalence of factor V Leiden mutation as the most frequent coagulation defect found in patients with venous thrombosis. The relationship between this mutation and cerebrovascular disease has not been established in adults. In this investigation, we studied 29 patients with ischemic stroke and 20 with intracerebral hemorrhage, all of whom were compared with 20 controls. A region of the factor V gene containing the Leiden mutation site was amplified with polymerase chain reaction and the presence of mutation was determined with restriction enzyme digestion. We found no evidence of an association between factor V Leiden mutation and ischemic stroke or intracerebral hemorrhage. There was no evidence of association in subgroup the analysis by age, smoking status, myocardial infarction, hypertension, diabetes mellitus, or coronary disease. Factor V Leiden mutation doesn't seem to be associated with a risk of cerebrovascular disease.     

Potential thrombophilic mutations/polymorphisms in patients with no flow-limiting stenosis after myocardial infarction

Background Although inherited thrombophilias are more common in patients with venous thromboembolism, their influence on the development of myocardial infarction (MI) requires clarification.Methods and Results To determine whether there are increased frequencies of mutations/polymorphisms in 14 genes potentially causing thrombophilia in patients with no flow-limiting stenoses after MI compared with patients with ≥1 flow-limiting stenosis of >50%, we studied 395 patients (60 with no flow-limiting stenosis) who underwent angiography at approximately 1 month. The mutations/polymorphisms studied included Factor V Leiden, prothrombin variant G20210A, β-fibrinogen 448 (G/A), endothelial protein C receptor (23-base pair insertion), methyl tetrahydrofolate reductase 677 (C/T), platelet glycoprotein IIIa PlA1/A2, plasminogen activator inhibitor-1 4G/5G, angiotensin II type 1 receptor (A/C), hemochromatosis gene 282 (G/A), nitric oxide synthase (NOS) (3 forms: eNOS, eNOS3, eNOS4), p22 phox of NADPH oxidase C242T, and angiotensin-converting enzyme insertion/deletion polymorphism. The frequencies of Factor V Leiden and the β-fibrinogen 448 A allele were higher in patients with no flow-limiting stenosis than in patients with ≥1 stenosis (11.7% vs 3.6%, odds ratio [OR] 3.6, 95% CI 1.3-9.4, P = .015; and 42% vs 27%, OR 2.0, 95% CI 1.1-3.5, P = .018, respectively), and there was a trend toward an increased frequency of prothrombin variant G20210A (6.7% vs 2.1%, OR 3.4, 95% CI 0.95-11.8, P = .069). However, in patients with no flow-limiting stenosis after MI the frequencies of the other gene mutations/polymorphisms were not increased. Also, there were no significant interactions between any of these 14 mutation/polymorphisms, major cardiovascular risk factors, and the absence of any flow-limiting stenosis, except for Factor V Leiden and hypertension (OR 6.34, 95% CI 2.67-100, P = .004).Conclusions Patients with no flow-limiting stenosis after MI had increased frequencies of 2 inherited thrombophilias (Factor V Leiden and β-fibrinogen 448 A allele), and there was a trend toward an increased frequency of prothrombin variant G20210A compared with patients with ≥1 stenosis. These data suggest that polymorphisms/mutations in some gene products influencing coagulation may influence the pathogenesis of MI. (Am Heart J 2003;145:118-24.)     

Coexistence of prothrombic risk factors and its relation to left ventricular thrombus in acute myocardial infarction

OBJECTIVE: Within the last few years a number of thrombophilic mutations have been identified. Pre-symptomatic testing for these established genetic risk factors identifies individuals predisposed to a disease and often allows to select suitable prophylactic interventions in time. We investigated whether or not the prothrombin G20210A allele, the factor V Leiden G1691A, and MTHFR C677T allele are risk factors for left ventricular thrombus (LV) in patients with myocardial infarction (AMI) or not. METHODS AND RESULTS: We analysed clinical, echocardiographic and biochemical data in 183 consecutive patients (aged 58 +/- 12 years; 34 women) with a first anterior acute myocardial infarction. Two-dimensional echocardiographic examination was performed on days 1, 3, 7, 15, and 30. LV thrombi were detected in 42 (23%) of the 183 patients with acute myocardial infarction. We have used multiplex assays based on PCR and DNA hybridization in microtitre plates for the simultaneous analysis of three mutations (FV Leiden G1691A, prothrombin G20210A, and MTHFR C677T). No significant differences in allele frequencies of FV Leiden G1691A (9.5% vs. 8.5%, p = 0.75), prothrombin G20210A (9.5% vs 7.1%, p = 0.74) and MTHFR C677T (47.6% vs. 50.3%, p = 0.74) were found in patients with LV thrombus when compared with those without LV thrombus. No significant differences in haemostatic factor levels were found in patients with LV thrombus when compared with those without LV thrombus. CONCLUSION: FV Leiden, prothrombin 20210 variant, and MTHFR mutation are no risk factors for left ventricular thrombus in patients with myocardial infarction.The presence of multiple mutations did not influence the development and outcome of LV thrombus in patients with myocardial infarction     

Prevalence of factor V Leiden and prothrombin variant G20210A in patients age <50 years with no significant stenoses at angiography three to four weeks after myocardial infarction

OBJECTIVES: We sought to determine the frequencies of factor V Leiden and prothrombin variant G20210A in patients age <50 years with no significant coronary stenoses three to four weeks after myocardial infarction (MI). BACKGROUND: Factor V Leiden and prothrombin variant G20210A occur frequently in patients with venous thromboembolism. However, the contribution of these mutations to the development of MI requires clarification. METHODS: The frequencies of factor V Leiden and prothrombin variant G20210A were determined in 41 patients age <50 years who had "normal" or "near normal" coronary arteries (no stenosis >50%) at angiography three to four weeks after MI (the study group) and compared with those in 114 patients who had at least one angiographic stenosis >50% after MI (the control group). Patients age > or =50 years with, or without, stenoses were also studied. RESULTS: The frequency of factor V Leiden was 14.6% in patients age <50 years in the study group compared with 3.6% in patients in the control group (odds ratio [OR] 4.7 [95% confidence interval (CI) 1.3-17.7], p = 0.02). The frequency of the prothrombin variant G20210A was 7.3% in the study group compared with 1.8% in the control group (OR 4.4 [95% CI 0.7-27.5], p = 0.12). One or both mutations were present in 8 of the 41 patients (19.5%) age <50 years in the study group compared with 6 of the 114 patients (5.5%) in the control group (OR 4.4 [95% CI 1.4-13.5], p = 0.01). In all 271 patients (irrespective of age) with normal arteries, the frequency of factor V Leiden was 11.7% (7/60) compared with 4.3% (9/211) in patients with at least one >50% stenosis (OR 2.9 [95% CI 1.1-8.3], p = 0.04), and the frequency of prothrombin variant G20210A was 6.7% (4/60) compared with 1.4% (3/211) (OR 4.9 [95% CI 1.1-22.8], p = 0.04), respectively. CONCLUSIONS: The frequencies of factor V Leiden and/or prothrombin variant G20210A are increased in patients age <50 years with normal or near normal coronary arteries after MI.     

Factor V Leiden is not commonly associated with idiopathic portal vein thrombosis in southern India.

BACKGROUND: Factor V Leiden has been reported in 2%-30% of patients with portal vein thrombosis. This wide variation makes it difficult to assess the importance of factor V Leiden as a predisposing factor. METHODS: Factor V Leiden was determined by restriction fragment length polymorphism in 112 patients with portal vein thrombosis, 104 with deep vein thrombosis and 98 control subjects. RESULTS: Only 3/112 (3%) patients with portal vein thrombosis had factor V Leiden, compared to 1/98 (1%) controls and 16/104 (15%) with deep vein thrombosis; of these, 3, 1 and 15, respectively, were heterozygous for this mutation. CONCLUSION: Factor V Leiden contributes little, if at all, to the development of portal vein thrombosis in southern India.