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

Integrating platelet and coagulation activation in fibrin clot formation

Platelets interact with the coagulation system in a multitude of ways, not only during the phases of thrombus formation, but also in specific areas within a formed thrombus. This review discusses current concepts of platelet control of thrombin generation, fibrin formation and structure, and anticoagulation. Indicated are how combined signalling via the platelet receptors for collagen (glycoprotein VI) and thrombin induces the secretion of (anti)coagulation factors, as well as surface exposure of phosphatidylserine, thereby catalysing thrombin generation. This procoagulant platelet response is also facilitated by the adhesive complexes glycoprotein Ib-V-IX and integrin αIIbβ3. In the buildup of a platelet-fibrin thrombus, the extrinsic, tissue factor-driven coagulation pathway is predominant in early stages, while the intrinsic, factor XII pathway seems to promote at later time points. Already early generation of thrombin enforces platelet responses and stimulates intra-thrombus heterogeneity with patches of loosely aggregated, contracted, and phosphatidylserine-exposing platelets. Fibrin actively formed on the surface of activated platelets supports thrombus growth, but also captures thrombin. The fibrin distribution in a thrombus appears to rely on the local procoagulant trigger and the blood flow rate. Clinical studies support the importance of the platelet-coagulation interplay, by showing beneficial effects of combination therapy in the secondary prevention of cardiovascular disease.

Use of D-dimer in oral anticoagulation therapy

Individualized anticoagulation management and improvement of the safety and effectiveness of oral anticoagulant have always been the focus of clinicians' attention. D-dimer, a sensitive marker of thrombosis and coagulation activation, is not only traditionally used in the diagnosis of venous thromboembolism, acute aortic dissection, and disseminated intravascular coagulation but can also be used as a helpful marker in the management of oral anticoagulant, including evaluating the anticoagulation quality, predicting clinical outcomes, and determining the optimal duration and intensity of anticoagulation.

Ticagrelor versus clopidogrel in East-Asian patients with acute coronary syndromes: a meta-analysis of randomized trials

Aim: To determine whether ticagrelor or clopidogrel provides the best outcomes for East-Asian patients with acute coronary syndrome (ACS). Materials & methods: Identification and interrogation of electronic databases through 26 July 2016 revealed fully randomized and controlled trials wherein primary efficacy end points were major adverse cardiovascular events and all-cause death among East-Asian patients with ACS. Major bleeding and noncoronary artery bypass grafts major bleeding were primary safety end points. Results: Two studies met the inclusion criteria. Compared with clopidogrel, ticagrelor has no statistical difference in the end points of major adverse cardiovascular events (risk ratio [RR]: 1.08; 95% CI: 0.62–1.91; p = 0.7260), myocardial infarction (RR: 1.200; 95% CI: 0.64–2.24; p = 0.5669), stroke (RR: 1.11; 95% CI: 0.46–2.66; p = 0.8165), cardiovascular death (RR: 0.89; 95% CI: 0.48–1.65; p = 0.7150), or all-cause mortality (RR: 0.92; 95% CI: 0.43–1.96; p = 0.8252). When compared with clopidogrel, it was found that ticagrelor provoked marked increases in major bleeding (RR: 1.48; p = 0.0430) and noncoronary artery bypass grafts-associated major bleeding (RR: 1.62; p = 0.0454). Conclusion: Ticagrelor and clopidogrel displayed similar efficacies in ACS presenting patients from East Asia. Administration of ticagrelor also displays some side effects including an increased risk of major bleeding.

Predictive Validity of CRUSADE, ACTION and ACUITY-HORIZONS Bleeding Risk Scores in Chinese Patients With ST-Segment Elevation Myocardial Infarction

BACKGROUND

The CRUSADE, ACTION and ACUITY-HORIZONS bleeding scores have been derived using Caucasian patients, and little is known about which has the better predictive ability in Chinese patients, especially for patients with STEMI.

METHODS AND RESULTS

We retrospectively analyzed 2,208 consecutive STEMI patients undergoing primary PCI (PPCI). Major bleeding events were defined according to Bleeding Academic Research Consortium criteria (type 3 or 5). Predictive ability of the 3 scores was assessed using logistic regression and AUC. Unadjusted HR for 1-year death were determined on Cox proportional hazard modeling. The major bleeding rate was 2.4%. The AUC of the CRUSADE, ACTION and ACUTIY-HORIZONS models was 0.88 (95% CI: 0.84-0.92), 0.90 (95% CI: 0.87-0.94), and 0.78 (95% CI: 0.87-0.94). The calibration of the ACUTIY-HORIZONS model was not acceptable overall, or in the subgroup of access site (P<0.05). In the high-risk category, 1-year mortality was approximately 4-7-fold greater than in the low-risk category (CRUSADE: HR, 7.27; 95% CI: 3.30-16.02, P<0.001; ACTION: HR, 7.13; 95% CI: 2.19-15.41, P<0.001; ACUITY-HORIZONS: HR, 4.06; 95% CI: 1.62-10.16; P=0.003).

CONCLUSIONS

The CRUSADE and ACTION scores have greater predictive ability for in-hospital major bleeding than the ACUITY-HORIZONS risk score in Chinese STEMI patients undergoing PPCI. Mortality would increase with the transition from low- to high-risk category in 1 year.

The Prognostic Value of Combinations of Genetic Polymorphisms in the ITGB3, ITGA2, and CYP2C19*2 Genes in Predicting Cardiovascular Outcomes After Coronary Bypass Grafting

AIM

To determine if there are any associations between the single nucleotide polymorphisms (SNPs): rs2046934, rs1126643, rs5918, rs6065, rs4244285; rs4986893 and the occurrence of cardiovascular events (CVE) in patients following coronary artery bypass grafting (CABG) surgery.

MATERIALS AND METHODS

The study included 130 CABG patients with stable angina grades II-IV. After CABG 69 of the patients were treated with acetylsalicylic acid (ASA) alone, and 61 received dual antiplatelet therapy (ASA+clopidogrel). Platelet function was assessed by light transmission aggregometry with adenosinediphosphate and arachidonic acid. The SNPs were identified by real-time polymerase chain reaction (PCR) with electrophoretic detection. The mean follow-up period was equal to 10.9 ± 5.2 months. The primary end point included the composite of all-cause mortality, myocardial infarction (MI), and ischemic stroke.

RESULTS

During the follow-up period 12 CVE were registered: 3 deaths, 6 MI, 3 strokes. Patients with composite mutant alleles of ITGB3+CYP2C19*2 or CYP2C19*2 + ITGA2, and with the mutant allele (*2) of CYP2C19, met end points more often than patients with other gene combinations (wild-type homozygotes, presence of one mutant allele of ITGB3 or ITGA2, the composite of mutant alleles of ITGB3+ITGA2 or ITGB3+ITGA2+CYP2C19*2; hazard ratio = 4, 95% confidence interval: 2.19-7.29, p = 0.008).

CONCLUSION

Carriage of a combination of mutant alleles in multiple genes including ITGB3+CYP2C19*2 or CYP2C19*2 + ITGA2 or CYP2C19*2 are possible predictors of CVE in patients after CABG.

Coagulation Factors and the Risk of Ischemic Heart Disease: A Mendelian Randomization Study

BACKGROUND

Coagulation plays a role in ischemic heart disease (IHD). However, which coagulation factors are targets of intervention is unclear. We assessed how genetically predicted vWF (von Willebrand factor), ETP (endogenous thrombin potential), FVIII (factor VIII), d-dimer, tPA (tissue-type plasminogen activator), and PAI (plasminogen activator inhibitor)-1 affected IHD. We similarly estimated effects on lipids to determine whether any associations were independent of lipids.

METHODS AND RESULTS

Separate sample instrumental variable analysis with genetic instruments, that is, Mendelian randomization, was used to obtain unconfounded estimates of effects on IHD using extensively genotyped studies of coronary artery disease/myocardial infarction, CARDIoGRAMplusC4D Metabochip (64 374 cases, 130 681 controls) and CARDIoGRAMplusC4D 1000 Genomes (60 801 cases, 123 504 controls), and on lipids using the Global Lipids Genetics Consortium Results (n=196 475). Genetically predicted ETP was positively associated with IHD (odds ratio, 1.05 per log-transformed SD; 95% confidence interval, 1.03-1.07) based on 15 single-nucleotide polymorphisms, as were vWF (odds ratio, 1.05 per SD; 95% confidence interval, 1.02-1.08) and FVIII (odds ratio, 1.06 per SD; 95% confidence interval, 1.03-1.09) based on 16 and 6 single-nucleotide polymorphisms, respectively, but the latter associations were null after considering pleiotropy. vWF and FVIII were associated with higher LDL (low-density lipoprotein) cholesterol, but not after considering pleiotropy. Genetically predicted d-dimer, tPA, and PAI-1 were not clearly associated with IHD or lipids based on 3, 3, and 5 single-nucleotide polymorphisms, respectively.

CONCLUSIONS

ETP may affect IHD. Assessing the role of its drivers in more precisely phenotyped studies of IHD could be worthwhile.

Associations of activated coagulation factor VII and factor VIIa-antithrombin levels with genome-wide polymorphisms and cardiovascular disease risk

ESSENTIALS

Essentials A fraction of coagulation factor VII circulates in blood as an activated protease (FVIIa). We evaluated FVIIa and FVIIa-antithrombin (FVIIa-AT) levels in the Cardiovascular Health Study. Polymorphisms in the F7 and PROCR loci were associated with FVIIa and FVIIa-AT levels. FVIIa may be an ischemic stroke risk factor in older adults and FVIIa-AT may assess mortality risk.

SUMMARY

Background A fraction of coagulation factor (F) VII circulates as an active protease (FVIIa). FVIIa also circulates as an inactivated complex with antithrombin (FVIIa-AT). Objective Evaluate associations of FVIIa and FVIIa-AT with genome-wide single nucleotide polymorphisms (SNPs) and incident coronary heart disease, ischemic stroke and mortality. Patients/Methods We measured FVIIa and FVIIa-AT in 3486 Cardiovascular Health Study (CHS) participants. We performed a genome-wide association scan for FVIIa and FVIIa-AT in European-Americans (n = 2410) and examined associations of FVII phenotypes with incident cardiovascular disease. Results In European-Americans, the most significant SNP for FVIIa and FVIIa-AT was rs1755685 in the F7 promoter region on chromosome 13 (FVIIa, β = -25.9 mU mL-1 per minor allele; FVIIa-AT, β = -26.6 pm per minor allele). Phenotypes were also associated with rs867186 located in PROCR on chromosome 20 (FVIIa, β = 7.8 mU mL-1 per minor allele; FVIIa-AT, β = 9.9 per minor allele). Adjusted for risk factors, a one standard deviation higher FVIIa was associated with increased risk of ischemic stroke (hazard ratio [HR], 1.12; 95% confidence interval [CI], 1.01, 1.23). Higher FVIIa-AT was associated with mortality from all causes (HR, 1.08; 95% CI, 1.03, 1.12). Among European-American CHS participants the rs1755685 minor allele was associated with lower ischemic stroke (HR, 0.69; 95% CI, 0.54, 0.88), but this association was not replicated in a larger multi-cohort analysis. Conclusions The results support the importance of the F7 and PROCR loci in variation in circulating FVIIa and FVIIa-AT. The findings suggest FVIIa is a risk factor for ischemic stroke in older adults, whereas higher FVIIa-AT may reflect mortality risk.

Myocardial infarction and thrombophilia: Do not miss the right diagnosis!

Protein C deficiency is a coagulation cascade disorder often resulting in venous thromboembolic events but is also a possible contributor to arterial thrombosis. To date, approximately ten cases of myocardial infarction (MI) due to protein C deficiency have been reported in the literature. However, affirming this mechanism requires ruling out the most common causes of MI, i.e. the rupture or erosion of an atherosclerotic plaque. Intravascular imaging of coronary arteries can be of help to identify angiographically undetected atherosclerosis. We report a case of an ST-segment elevation myocardial infarction (STEMI) in a young man with apparent evidence of arterial thrombosis resulting from protein C deficiency and heterozygous factor Leiden mutation which was contradicted by intravascular imaging demonstrating atherosclerosis.

Evolution of Factor V Leiden

Factor V Leiden is a procoagulant mutation associated with venous and arterial thrombosis and pregnancy complications. Its high prevalence of 5% in Caucasians suggests that there are evolutionary benefits as well. Carriers are indeed reported to have various advantageous phenotypes related to haemostasis, inflammation and fertility: less acute blood loss; less menstrual blood loss; decreased risk of intracranial haemorrhage; milder phenotypes of haemophilia; higher survival in and lower susceptibility to severe sepsis; higher survival in acute respiratory distress syndrome; less severe diabetic nephropathy and higher fecundity in both men and women. Not all these associations come from high quality adequately powered studies and many have not been confirmed by further research. The evolutionary influence of the alleged associations varies and is difficult to establish, partly due to a shift over time in risk factors of the diseases concerned. For most of the phenotypes possible mechanistic explanations can be provided. The procoagulant phenotype and perhaps also certain pregnancy complications follow from activated protein C (APC) resistance. Elevated APC levels possibly mediate anti-inflammatory effects. Higher sperm counts and more successful embryo implantation seem to play a role in the increased fecundity.

Association of FV G1691A Polymorphism but not A4070G With Coronary Artery Disease

Coronary artery disease (CAD) is one of the chief causes of death in the world. Several hypotheses have been promoted as for the origin of the disease, among which are genetic predispositions and/or environmental factors. The aim of this study was to determine the effect of factor V (FV) gene polymorphisms (Leiden, G1691A [FVL] and HR2 A4070G) and to analyze their association with traditional risk factors in assessing the risk of CAD. Our study population included 200 Tunisian patients with symptomatic CAD and a control group of 300 participants matched for age and sex. All participants were genotyped for the FVL and HR2 polymorphisms. Multivariate logistic regression was applied to analyze independent factors associated with the risk of CAD. Our analysis showed that the FVL A allele frequency (P < 10^–3, odds ratio [OR] = 2.81, 95% confidence interval [CI] = 1.6-4.9) and GA genotype (P < 10^–3, OR = 4.03, 95% CI = 2.1-7.6) are significantly more prevalent among patients with CAD compared to those controls and may be predisposing to CAD. We further found that the FVL mutation is an independent risk factor whose effect is not modified by other factors (smoking, diabetes, hypertension, dyslipidemia, and a family history of CAD) in increasing the risk of the disease. However, analysis of FV HR2 variation does not show any statistically significant association with CAD. The FVL polymorphism may be an independent risk factor for CAD. However, further investigations on these polymorphisms and their possible synergisms with traditional risk factors for CAD could help to ascertain better predictability for CAD susceptibility.

The relevance of coagulation in cardiovascular disease: what do the biomarkers tell us?

Several haemostatic factors have been associated with incident arterial cardiovascular disease in prospective studies and meta-analyses. Plasma fibrinogen shows a strong and consistent association with risk; however, this may reflect its inflammatory marker status, and causality remains to be proven. The common haemostatic gene polymorphisms for factor II, factor V and the von Willebrand factor: Factor VIII (non-O blood group) show significant associations with coronary heart disease (CHD) risk, consistent with potential causality. Increased D-dimer and t-PA antigen levels are associated with CHD risk, suggesting roles for coagulation activation and endothelial disturbance. There is little evidence for associations with CVD with other haemostatic factors.

D-dimer to guide the intensity of anticoagulation in Chinese patients after mechanical heart valve replacement: a randomized controlled trial

Essentials Low anticoagulation intensity reduces bleeding but increases thrombosis during warfarin therapy. Elevated D-dimer level is associated with increased thrombosis events. D-dimer can be used to find potential thrombosis in those receiving low intensity therapy. D-dimer-guided therapy may be the optimal strategy for those with mechanical heart valve replacement.

SUMMARY

Background Controversies remain regarding the optimal anticoagulation intensity for Chinese patients after mechanical heart valve replacement despite guidelines having recommended a standard anticoagulation intensity. Objectives To investigate whether D-dimer could be used to determine the optimal anticoagulation intensity in Chinese patients after mechanical heart valve replacement. Patients/Methods This was a prospective, randomized controlled clinical study. A total of 748 patients following mechanical heart valve replacement in Wuhan Asia Heart Hospital were randomized to three groups at a ratio of 1 : 1 : 1. Patients in two control groups received warfarin therapy based on constant standard intensity (international normalized ratio [INR], 2.5-3.5; n = 250) and low intensity (INR, 1.8-2.6; n = 248), respectively. In the experimental group (n = 250), warfarin therapy was initiated at low intensity, then those with elevated D-dimer levels were adjusted to standard intensity. All patients were followed-up for 24 months until the occurrence of endpoints, including bleeding events, thrombotic events and all-cause mortality. Results A total of 718 patients were included in the analysis. Fifty-three events occurred during follow-up. There was less hemorrhage (3/240 vs. 16/241; hazard ratio [HR], 0.18; 95% confidence interval [CI], 0.07-0.45) and all-cause mortality (4/240 vs. 12/241; HR, 0.33; 95% CI, 0.12-0.87) observed in the D-dimer-guided group than in the standard-intensity group. A lower incidence of thrombotic events was also observed in the D-dimer-guided group when compared with the low-intensity group (5/240 vs. 14/237; HR, 0.35; 95% CI, 0.14-0.85). Overall, the total events were less in the D-dimer-guided group (9/240) when compared with the other two control groups (24/241, 20/237; HR, 0.37, 0.44; 95% CI, 0.19-0.72, 0.21-0.90 Conclusions The D-dimer-guided adjustment of anticoagulation intensity could reduce adverse events in Chinese patients after mechanical heart valve replacement.

TRIAL REGISTRY

NCT01996657; ClinicalTrials.gov.

Genetic Polymorphisms of Hemostatic Factors and Thrombotic Risk in Non BCR-ABL Myeloproliferative Neoplasms: A Pilot Study

The most important complications of Philadelphianegagive (non BCR-ABL) myeloproliferative neoplasms (MPNs) are vascular events. Our aim was to evaluate the effects of single nucleotide polymorphisms (SNPs), platelet glycoproteins (GPs) (Ia/IIa, Ibα, IIb/IIIa and VI), von Willebrand factor (vWF), coagulation factor VII (FVII), β-fibrinogen, and the risk of thrombosis in patients with non BCR-ABL MPNs at the Lithuanian University of Health Sciences. Kaunas, Lithuania. Genotyping was done for 108 patients. The TT genotype of the GP Ia/IIa c.807C>T polymorphism was more frequently found in the group of MPN patients with arterial thrombosis compared to MPN patients who were thrombosis-free [26.5 vs. 11.5%, p = 0.049; odds ratio (OR) 2.68; 95% confidence interval (95% CI) 1.01-7.38]. The CT genotype of the β-fibrinogen c.-148C>T polymorphism occurred more frequently in MPN patients with arterial, and total thrombosis compared to the wild or homozygous genotype (57.7 vs. 40.0 vs. 12.5%; p = 0.027), (64.7 vs. 44.4 vs. 25%; p = 0.032), respectively. The carrier state for the c.-323P10 variant of FVII SNP (summation of P10/10 and P0/10) was more frequent in MPN patients with thrombosis compared to the wild-type genotype carriers (71.4 vs. 43.4%; p = 0.049; OR 3.26; 95% CI 1.01-11.31). The coexistence of heterozygous β-fibrinogen c.-148C>T and FVII c.-323P0/10 SNP, increased the risk of arterial thrombosis (21.1 vs. 3.7%, p = 0.008; OR 6.93; 95% CI 1.38-34.80). The TT genotype of GP Ia/IIa c.807C>T, the CT genotype of β-fibrinogen c.-148C>T and FVII c.-323P0/10 SNP could be associated with risk of thrombosis in MPN patients.

Impact of Venous Thromboembolism on the Formation and Progression of Carotid Atherosclerosis: The Tromsø Study

Venous thromboembolism (VTE) is associated with increased risk of arterial cardiovascular diseases (CVD), and development of atherosclerosis secondary to VTE may be an intermediate between VTE and CVD. Therefore, we aimed to investigate whether incident VTE was associated with subsequent carotid atherosclerosis formation and progression in a population-based observational study. Subjects attending two or more ultrasound examinations of the right carotid artery, with measurement of total plaque area (TPA), in the Tromsø Study in 1994–1995, 2001–2002, and/or 2007–2008 were eligible. We identified 150 subjects diagnosed with first-lifetime VTE between the initial and follow-up visit, and randomly selected 600 age- and sex-matched subjects without VTE between the visits. Subjects with VTE and carotid plaque(s) at the first visit had 4.1 mm ² (β: 4.13, 95% CI: −1.72 to 9.98) larger change in TPA between the first and second visit compared with subjects without VTE after adjustment for change in high-sensitivity C-reactive protein (hs-CRP) and traditional atherosclerotic risk factors. The association remained after restricting the analyses to VTE events diagnosed in the first half of the time interval between the carotid ultrasounds (β: 4.02, 95% CI: −3.66 to 11.70), supporting that the change in TPA occurred subsequent to the VTE. No association was found between VTE and novel carotid plaque formation. In conclusion, we found a possible association between VTE and atherosclerosis progression in those with already established carotid plaques, but not between VTE and novel plaque formation. The association between VTE and carotid plaque progression was not mediated by low-grade inflammation assessed by hs-CRP.

A Prothrombotic Score Based on Genetic Polymorphisms of the Hemostatic System Differs in Patients with Ischemic Stroke, Myocardial Infarction, or Peripheral Arterial Occlusive Disease

Background

While twin studies indicate a genetic component in arterial thrombosis such as ischemic stroke, myocardial infarction (MI), or peripheral arterial occlusive disease (PAOD), the clinical relevance of hemostatic polymorphisms in arterial thrombosis is a matter of debate.

Methods

We analyzed the prevalence of 13 hemostatic polymorphisms [PAI-1, PLAT, F5 (including factor V Leiden and HR2 haplotype), F2, F7, F13A, FGB, TFPI, THBD, MTHFR, ACE, and ITGA2] in patients referred to a tertiary referral center. A “prothrombotic score” was calculated by dividing the number of risk-increasing polymorphisms for thrombosis minus the number of risk-lowering polymorphisms (F7 and F13A) by the number of polymorphisms tested.

Results

Datasets of 144 patients with prior ischemic stroke (mean age 44 ± 13 years; 65% female) were compared to 62 patients with MI or PAOD (mean age 54 ± 14 years; 47% female). The prothrombotic score was lower in MI and PAOD patients compared to stroke patients [odds ratios 2.7 (95% confidence intervals 1.1–6.2)]. Frequencies of individual polymorphisms did not differ between both groups.

Conclusion

Patients with MI or PAOD had a lower burden of prothrombotic mutations compared to patients with prior stroke, indicating that a prothrombotic state might play a different role in distinct forms of arterial thrombosis.

The Role of Emerging Risk Factors in Cardiovascular Outcomes

PURPOSE OF REVIEW

This review discusses the recent evidence for a selection of blood-based emerging risk factors, with particular reference to their relation with coronary heart disease and stroke.

RECENT FINDINGS

For lipid-related emerging risk factors, recent findings indicate that increasing high-density lipoprotein cholesterol is unlikely to reduce cardiovascular risk, whereas reducing triglyceride-rich lipoproteins and lipoprotein(a) may be beneficial. For inflammatory and hemostatic biomarkers, genetic studies suggest that IL-6 (a pro-inflammatory cytokine) and several coagulation factors are causal for cardiovascular disease, but such studies do not support a causal role for C-reactive protein and fibrinogen. Patients with chronic kidney disease are at high cardiovascular risk with some of this risk not mediated by blood pressure. Randomized evidence (trials or Mendelian) suggests homocysteine and uric acid are unlikely to be key causal mediators of chronic kidney disease-associated risk and sufficiently large trials of interventions which modify mineral bone disease biomarkers are unavailable. Despite not being causally related to cardiovascular disease, there is some evidence that cardiac biomarkers (e.g. troponin) may usefully improve cardiovascular risk scores. Many blood-based factors are strongly associated with cardiovascular risk. Evidence is accumulating, mainly from genetic studies and clinical trials, on which of these associations are causal. Non-causal risk factors may still have value, however, when added to cardiovascular risk scores. Although much of the burden of vascular disease can be explained by 'classic' risk factors (e.g. smoking and blood pressure), studies of blood-based emerging factors have contributed importantly to our understanding of pathophysiological mechanisms of vascular disease, and new targets for potential therapies have been identified.

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.

An Overview of Thrombophilia and Associated Laboratory Testing

Venous thromboembolism, usually entailing deep vein thrombosis, pulmonary embolism, or both, is a complex and multifactorial disorder, in which a number of putative conditions interplay and finally contribute to propel the individual risk over a certain degree, so ultimately culminating in the development of venous occlusive disorders. Thrombophilia is commonly defined as a propensity to develop venous thromboembolism on the basis of an underlying hypercoagulable state attributable to inherited or acquired disorders of blood coagulation or fibrinolysis. The thrombophilic conditions are conventionally classified as inherited (or genetically determined) and acquired. The former include deficiencies of natural anticoagulants such as antithrombin, protein C, protein S, increased values of clotting factors (especially factor VIII), as well as prothrombotic polymorphisms in genes encoding for factor V (i.e., factor V Leiden) and prothrombin. The latter conditions mainly entail antiphospholipid antibody syndrome, malignancy, acquired elevations of coagulation factors or acquired reduction of natural inhibitors, or hyperhomocysteinemia. Deepened knowledge of all potential risk factors, as well as the clear understanding of their role in the pathophysiology of venous thrombosis, are both essential to help achieve a faster and more efficient diagnosis of this condition as well as a more effective prophylaxis of patients at higher risk and treatment of those with manifest disease.

Platelet glycoprotein gene Ia C807T, HPA-3, and Ibα VNTR polymorphisms are associated with increased ischemic stroke risk: Evidence from a comprehensive meta-analysis

Background/aims

Platelet glycoproteins play a crucial role in the initial stage of thrombus formation and may contribute to the pathophysiology of atherosclerosis. Polymorphisms in glycoprotein genes alter the function of the protein, possibly leading to increased risk of ischemic stroke. However, previous genetic association studies that examined the relationship between glycoprotein genes polymorphisms and ischemic stroke have yielded inconsistent results. This study aimed to evaluate the association between glycoprotein genes and ischemic stroke by the application of meta-analysis.

Methods

Relevant studies were identified by an extensive search through databases. The quality of included studies was assessed independently using the Newcastle–Ottawa Scale. Allele and genotype frequencies for each included study were extracted. The odds ratio (OR) with 95% confidence interval (95%CI) was calculated using a random-effects or fixed-effects model. Q statistic was used to evaluate homogeneity, and a meta-regression model was used to explore the study-level variables and to describe the heterogeneity in included studies. Egger’s test and funnel plot were used to assess publication bias.

Results

A total of 60 studies (9 polymorphisms) were included and identified in the current meta-analysis. The Newcastle–Ottawa Scale scores ranged from 7 to 9 except for two studies with Newcastle–Ottawa Scale scores of 6. The T allele or TT genotype of the glycoprotein Ia C807T polymorphism were associated with an increased susceptibility to ischemic stroke in combined population (807T allele: OR, 95%CI: 1.24, 1.03–1.50, p = 0.02) or Asian populations (807T allele: OR, 95%CI: 1.31, 1.10–1.54, p = 0.002 and 807TT genotype: OR, 95%CI: 1.53, 1.13–2.08, p = 0.006, respectively), and the Ser allele of HPA-3 was associated with increased risk of ischemic stroke in combined population or in Asians (OR, 95%CI: 1.21, 1.04–1.40, p = 0.01 or 1.54, 1.18–2.01, p = 0.001). Of note, the Ser/Ser genotype was more common in Asians (OR, 95%CI: 2.09, 1.40–3.13, p < 0.001). For glycoprotein Ibα variable number tandem repeat, only B allele showed a mild significant association with ischemic stroke risk in combined population or in Caucasians (OR, 95%CI: 2.17, 1.04–4.55, p = 0.04 or 1.79, 1.02–3.13, p = 0.04). There was no significant association between HPA-1, HPA-2, HPA-4, HPA-5, glycoprotein Ibα-5 T/C as well as Ia G873A polymorphisms and increased risk of ischemic stroke.

Conclusions

We found that glycoprotein Ia C807T T allele or the TT genotype, the Ser-allele of HPA-3 and B allele of glycoprotein Ibα variable number tandem repeat polymorphisms were associated with increased risk for ischemic stroke. Future studies with larger sample sizes will be necessary to confirm the results. In addition, analyses of ischemic stroke subtypes and gene–gene and gene–environment interactions are warranted.

G2691A and C2491T mutations of factor V gene and pre-disposition to myocardial infarction in Morocco

Coagulation factor Leiden mutation has been described as a common genetic risk factor for venous thrombosis; however, this mutation was reported to be practically absent in an African population. Recently, a novel non-sense mutation in the gene encoding factor V has been associated with the risk of occurrence of cardio-cerebrovascular diseases such as stroke and venous thrombosis. The aim of the present study was to investigate whether the factor V Leiden (FVL) and C2491T non-sense mutations are associated with the risk of developing myocardial infarction. Genotyping of FVL and C2491T FV was performed using the polymerase chain reaction restriction fragment length polymorphism method on a sample of 100 patients with myocardial infarction as well as 211 controls. In the study population, the frequency of the FVL mutation was practically zero. However, with regard to the C2491T mutation, the TT genotype was associated with an increased risk of myocardial infarction [odds ratio (OR)=3.16, 95% confidence interval (CI): 1.29-7.71, P=0.03]. A significant association between the C2491T FV mutation and the risk of myocardial infarction was identified using recessive (OR=2.74, 95% CI: 1.14-6.58, P=0.04), dominant (OR=1.85, 95% CI: 1.13-3.04, P=0.02) and additive (OR=1.88, 95% CI: 1.25-2.80, P=0.004) models. Furthermore, a positive correlation was found between the presence of the C2491T FV mutation and hypertension (P=0.02), which is associated with myocardial infarction. In conclusion, the results of the present study suggested that the C2491T non-sense mutation of the FV gene may be a risk factor for myocardial infarction in a Moroccan population.

Update on the Cardiovascular Risks of Hormone Replacement Therapy

Systematic reviews of randomized, controlled trials have shown that use of hormone replacement therapy in women increases the risk of total cardiovascular disease (venous thromboembolism, stroke and coronary heart disease; there may also be an increased risk of peripheral arterial disease). The relative increase in risk is similar to that for use of combined oral contraceptives, but the absolute increase in risk is higher owing to the higher age of hormone replacement therapy users. The increased risk appears confined to current users, increases with age and obesity, and may differ with type of preparation. Transdermal hormone replacement therapy may carry a lower risk of venous thromboembolism compared with oral hormone replacement therapy. The mechanism for the increased risk is probably activated blood coagulation. The risk of venous thromboembolism is higher in women with thrombophilias; however, the value of screening for thrombophilias is not established. Further research is required to establish the risks of cardiovascular (and other) diseases in different groups of women for different types of hormone replacement therapy, including an individual participant meta-analysis of reported randomized, controlled trials.

Association Between the G20210A Polymorphism of Prothrombin Gene and Myocardial Infarction in Tunisian Population

The prothrombin is the precursor of the serine protease thrombin, a key enzyme in homeostasis. Prothrombin G20210A polymorphism (rs1799963) was described as a moderate risk factor for venous thrombosis because this mutation is associated with prothrombin elevated levels which may lead to an imbalance between the procoagulant, anticoagulant, and fibrinolytic system. 20210A carriers have an increased risk of thrombosis. In this study, we proposed to determine the prevalence of 20210A prothrombin variant among Tunisian population, and to evaluate the potential relevance of this variant with myocardial infarction. This study included 1290 unrelated Tunisians (1007 male and 283 female) divided in two groups: Four hundred and eighty-seven MI patients (mean age: 52.64 ± 8.98 years) and 803 apparently healthy controls (mean age: 51 ± 8.99). The prothrombin G20210A polymorphism was carried out by polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) analysis. The distribution of genotypes was in accordance with Hardy-Weinberg equilibrium (p > 0.05). A significant difference in genotype distribution and allele frequency was observed between patients and controls. Male patients with MI had a frequency of 97 % for GG genotype and 3 % for GA+AA genotypes. The control group had a frequency of 99 % for the GG genotype and 1 % for the GA+AA genotypes which is significantly lower than the frequency found in patients (p = 0.01). The same genotype frequencies were found in women (p = 0.032). The MI patient group showed a significantly higher frequency of 20210A allele compared to controls 0.02 versus 0.01 [OR = 3.60 (95 % CI = 1.29-10.53), p = 0.005] in men and 0.015 versus 0.068 [OR = 4.68 (95 % CI = 1.60-14.26), p = 0.001] in women. Our work showed a significant but not independent association between the G20210A polymorphism of the prothrombin gene and MI in the Tunisian population.

Genetics of the acute coronary syndrome

Acute coronary artery syndrome in the leading cause of morbidity and mortality in Western countries, and its epidemiological burden is also constantly increasing worldwide, including Asia. Due to social and economic consequences, a number of experimental and epidemiological studies have analyzed its etiology so far, in order to develop effective preventive and treatment measures. Thanks to these studies, it is now clear that coronary artery disease (CAD) is a complex multifactorial disorder, resulting from close interaction between acquired and inherited risk factors. In particular, considerable advances were made in the last decade about our understanding of the genetic causes of CAD, mainly propelled by the progresses in whole genome scanning and the development of genome wide association studies. This narrative review is hence dedicated to explore the role of genetic factors in the risk of developing acute CAD.

Impact of incident myocardial infarction on the risk of venous thromboembolism: the Tromsø Study

Essentials Registry-based studies indicate a link between arterial- and venous thromboembolism (VTE). We studied this association in a cohort with confounder information and validated outcomes. Myocardial infarction (MI) was associated with a 4.8-fold increased short-term risk of VTE. MI was associated with a transient increased risk of VTE, and pulmonary embolism in particular.

SUMMARY

Background Recent studies have demonstrated an association between venous thromboembolism (VTE) and arterial thrombotic diseases. Objectives To study the association between incident myocardial infarction (MI) and VTE in a prospective population-based cohort. Methods Study participants (n = 29 506) were recruited from three surveys of the Tromsø Study (conducted in 1994-1995, 2001-2002, and 2007-2008) and followed up to 2010. All incident MI and VTE events during follow-up were recorded. Cox regression models with age as the time scale and MI as a time-dependent variable were used to calculate hazard ratios (HRs) of VTE adjusted for sex, body mass index, blood pressure, diabetes mellitus, HDL cholesterol, smoking, physical activity, and education level. Results During a median follow-up of 15.7 years, 1853 participants experienced an MI and 699 experienced a VTE. MI was associated with a 51% increased risk of VTE (HR 1.51; 95% confidence interval [CI] 1.08-2.10) and a 72% increased risk of pulmonary embolism (PE) (HR 1.72; 95% CI 1.07-2.75), but not significantly associated with the risk of deep vein thrombosis (DVT) (HR 1.36; 95% CI 0.86-2.15). The highest risk estimates for PE were observed during the first 6 months after the MI (HR 8.49; 95% CI 4.00-18.77). MI explained 6.2% of the PEs in the population (population attributable risk) and 78.5% of the PE risk in MI patients (attributable risk). Conclusions Our findings indicate that MI is associated with a transient increased VTE risk, independently of traditional atherosclerotic risk factors. The risk estimates were particularly high for PE.

Quadruple Vessel Coronary Artery Bypass Grafting in a 14-Year-Old Child With Plasminogen Activator Inhibitor-1 4G/4G Gene Polymorphism

Myocardial ischemia due to coronary artery disease is an extremely rare condition in childhood and adolescence. Absence of obvious serious risk factors remains a challenge to modern cardiology. We present the case of a 14-year-old boy who underwent quadruple-vessel coronary artery bypass grafting with bilateral pedicled internal mammary artery and bilateral radial artery grafting. We try to highlight a rare but important 4G variant PAI-1 (SERPINE 1) gene mutation as the etiology of severe coronary artery disease in our patient. To the best of our knowledge, he is one of the youngest patients who underwent coronary artery bypass surgery with 4 arterial grafts.

Tissue Factor Pathway Inhibitor, Activated Protein C Resistance, and Risk of Coronary Heart Disease Due To Combined Estrogen Plus Progestin Therapy

OBJECTIVE

To examine whether tissue factor pathway inhibitor or acquired activated protein C (APC) resistance influences the increased risk of coronary heart disease (CHD) due to estrogen plus progestin therapy.

APPROACH AND RESULTS

Prospective nested case-control study of 205 cases of CHD and 481 matched controls in the Women's Health Initiative randomized trial of estrogen plus progestin therapy. After multivariable covariate adjustment, both baseline tissue factor pathway activity (P=0.01) and APC resistance (P=0.004) were associated positively with CHD risk. Baseline tissue factor pathway activity and APC resistance singly or jointly did not significantly modify the effect of estrogen plus progestin on CHD risk. Compared with placebo, estrogen plus progestin decreased tissue factor pathway inhibitor activity and increased APC resistance but these changes did not seem to modify or mediate the effect of estrogen plus progestin on CHD risk.

CONCLUSIONS

Tissue factor pathway inhibitor activity and APC resistance are related to CHD risk in women, but may not explain the increased CHD risk due to estrogen plus progestin therapy. The data from this study do not support the clinical use of measuring these hemostatic factors to help stratify risk before hormone therapy.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000611.

Interaction of Hereditary Thrombophilia and Traditional Cardiovascular Risk Factors on the Risk of Arterial Thromboembolism

Background—

Hereditary thrombophilia is associated with a slightly increased risk of arterial thromboembolism (ATE). Whether hereditary thrombophilia interacts with traditional cardiovascular risk factors on the risk of ATE has yet to be established.

Methods and Results—

A total of 1891 individuals belonging to 4 family cohorts from the Netherlands were included in the analyses. Five hereditary thrombophilic defects, including factor V Leiden, prothrombin G20210A defect, and deficiencies of the natural anticoagulants (ie, antithrombin, protein C, and protein S), were assessed, and data on risk factors and previous ATE were collected. Thrombophilia was associated with elevated risk of ATE (hazard ratio =1.74, 95% confidence interval, 1.18–2.58; P =0.005). Overall, the association of thrombophilia with ATE tended to be stronger in the presence of traditional cardiovascular risk factors, especially the synergistic effect of thrombophilia with diabetes mellitus was striking (hazard ratio of thrombophilia–ATE association was 1.41 in nondiabetics versus 8.11 in diabetics). Moreover, the association of thrombophilia with ATE tended to be stronger in females and before the age of 55 years as compared with males and individuals >55 years of age, respectively.

Conclusions—

Thrombophilia is associated with ATE. This association may be stronger in the presence of traditional cardiovascular risk factors in particular in individuals with diabetes mellitus. Future studies on thrombophilia–ATE risk should focus on high-risk populations with high prevalence of traditional cardiovascular risk factors.

Acute Fibrinolysis Shutdown after Injury Occurs Frequently and Increases Mortality: A Multicenter Evaluation of 2,540 Severely Injured Patients

BACKGROUND

Fibrinolysis is a physiologic process that maintains microvascular patency by breaking down excessive fibrin clot. Hyperfibrinolysis is associated with a doubling of mortality. Fibrinolysis shutdown, an acute impairment of fibrinolysis, has been recognized as a risk factor for increased mortality. The purpose of this study was to assess the incidence and outcomes of fibrinolysis phenotypes in 2 urban trauma centers.

STUDY DESIGN

Injured patients included in the analysis were admitted between 2010 and 2013, were 18 years of age or older, and had an Injury Severity Score (ISS) > 15. Admission fibrinolysis phenotypes were determined by the clot lysis at 30 minutes (LY30): shutdown ≤ 0.8%, physiologic 0.9% to 2.9%, and hyperfibrinolysis ≥ 3%. Logistic regression was used to adjust for age, arrival blood pressure, ISS, mechanism, and facility.

RESULTS

There were 2,540 patients who met inclusion criteria. Median age was 39 years (interquartile range [IQR] 26 to 55 years) and median ISS was 25 (IQR 20 to 33), with a mortality rate of 21%. Fibrinolysis shutdown was the most common phenotype (46%) followed by physiologic (36%) and hyperfibrinolysis (18%). Hyperfibrinolysis was associated with the highest death rate (34%), followed by shutdown (22%), and physiologic (14%, p < 0.001). The risk of mortality remained increased for hyperfibrinolysis (odds ratio [OR] 3.3, 95% CI 2.4 to 4.6, p < 0.0001) and shutdown (OR 1.6, 95% CI 1.3 to 2.1, p = 0.0003) compared with physiologic when adjusting for age, ISS, mechanism, head injury, and blood pressure (area under the receiver operating characteristics curve 0.82, 95% CI 0.80 to 0.84).

CONCLUSIONS

Fibrinolysis shutdown is the most common phenotype on admission and is associated with increased mortality. These data provide additional evidence of distinct phenotypes of coagulation impairment and that individualized hemostatic therapy may be required.

Skin Necrosis in a Patient with Factor V Leiden Mutation following Nipple Sparing Mastectomy

Nipple-sparing mastectomy (NSM) and immediate breast reconstruction have replaced radical surgical interventions for the treatment of selected patients with breast cancer undergoing prophylactic mastectomy. NSM is technically a difficult procedure. After dissection, the remaining breast skin and nipple-areola complex (NAC) must be thin enough to be free of tumor tissue and thick enough to preserve tissue perfusion. Factor V Leiden mutation is the most common cause of hereditary thrombophilia; thrombosis almost always develops in the venous system. The literature includes only a few case series of arterial thrombosis. The present study aimed to describe for the first time a patient with Factor V Leiden mutation that developed nipple-areola complex and skin necrosis, and multiple embolisms in the upper extremity arteries following NSM.

The effect of moderate alcohol consumption on biomarkers of inflammation and hemostatic factors in postmenopausal women

BACKGROUND/OBJECTIVES

Inflammation and hemostasis contribute to the etiology of cardiovascular disease. We previously demonstrated that moderate alcohol consumption (1-2 drinks/day) may decrease risk for cardiovascular disease because of an improved lipid profile. In addition to these beneficial changes, the alcohol-mediated reduction in risk may be through its effect on inflammation and hemostasis. The objective of the study was to evaluate the effect of moderate alcohol consumption on biomarkers of inflammation and hemostasis in postmenopausal women.

SUBJECTS/METHODS

As part of a controlled diet study, 53 postmenopausal women each consumed a weight-maintaining diet plus 0, 15 and 30 g/day of alcohol for 8 weeks, in a randomized crossover design. The controlled diet contained 15%, 53% and 32% of energy from protein, carbohydrate and fat, respectively.

RESULTS

Soluble intercellular adhesion molecule-1 decreased by 5% (P<0.05) with consumption of both 15 and 30 g of alcohol. Fibrinogen concentrations decreased by 4% and 6% (P<0.05) after consumption of 15 and 30 g alcohol, respectively. Fibrin D-dimer decreased by 24% (P<0.05) after consumption of 30 g of alcohol. Plasminogen activator inhibitor-1 (PAI-1) concentrations were increased 27 and 54% (P<0.05) after consumption of 15 and 30 g of alcohol. Plasma high-sensitivity C-reactive protein, interleukin-6 and factor VII coagulant activity did not change with alcohol consumption.

CONCLUSIONS

These data suggest that moderate alcohol consumption may have beneficial effects on inflammation and hemostasis in postmenopausal women, and this may be somewhat mitigated by an increase in PAI-1.

Adipose tissue and metabolic syndrome: too much, too little or neither

Obesity is strongly associated with metabolic syndrome. Recent research suggests that excess adipose tissue plays an important role in development of the syndrome. On the other hand, persons with a deficiency of adipose tissue (e.g. lipodystrophy) also manifest the metabolic syndrome. In some animal models, expansion of adipose tissue pools mitigates adverse metabolic components (e.g. insulin resistance, hyperglycaemia and dyslipidemia). Hence, there are conflicting data as to whether adipose tissue worsens the metabolic syndrome or protects against it. This conflict may relate partly to locations of adipose tissue pools. For instance, lower body adipose tissue may be protective whereas upper body adipose tissue may promote the syndrome. One view holds that in either case, the accumulation of ectopic fat in muscle and liver is the driving factor underlying the syndrome. If so, there may be some link between adipose tissue fat and ectopic fat. But the mechanisms underlying this connection are not clear. A stronger association appears to exist between excessive caloric intake and ectopic fat accumulation. Adipose tissue may act as a buffer to reduce the impact of excess energy consumption by fat storage; but once a constant weight has been achieved, it is unclear whether adipose tissue influences levels of ectopic fat. Another mechanism whereby adipose tissue could worsen the metabolic syndrome is through release of adipokines. This is an intriguing mechanism, but the impact of adipokines on metabolic syndrome risk factors is uncertain. Thus, many potential connections between adipose tissue and metabolic syndrome remain to unravelled.

Prevalence and significance of two major inherited thrombophilias in infective endocarditis

The pathogenesis of infective endocarditis (IE) involves activation of the haemostasis system at the site of endocardial defects. Whether prothrombotic conditions are associated with IE by enhancing early vegetation formation is unknown. In this study, we assess the prevalence and clinical significance of two major conditions associated with thrombophilia in patients with IE. Mutations G20210A of the prothrombin (PTH) gene and G1691A of factor V (FV Leiden) gene were studied by means of allele-specific polymerase chain reaction in 203 IE patients, 175 valvular heart disease (VHD) patients and 200 blood donors (BD). IE patients show higher cumulative frequencies of mutated alleles of PTH and FV Leiden [6.4 vs 3.25 %; OR 2.03 (95 % CI 0.97-3.66); p = 0.047] compared to BD, but not VHD. Device-related IE is enriched with FV Leiden, and prosthetic valve IE with PTH mutations (allele frequency 8.3 vs 2.2 % in native valve IE; p = 0.021). Vegetation size and embolic complications are not influenced by the examined thrombophilias. A trend for a higher mortality was observed in IE patients with any of the two thrombophilias studied. Our data do not support a role for factor V Leiden and G20210A prothrombin gene mutations in the susceptibility to IE. Whether any of these genetic polymorphisms play a role in a specific subtype of IE needs to be re-examined in larger studies.

The role of hypercoagulability in ischemic colitis

OBJECTIVE

The aim of this study is to evaluate the role of thrombophilia-hypercoagulability in ischemic colitis (IC).

MATERIAL AND METHODS

Thrombophilia and fibrinogen were evaluated in 56 cases of IC and 44 controls with known predisposing factors but no evidence of IC. Thrombophilic factors tested were: protein C (PC), protein S, antithrombin (AT), resistance to activated protein C (APCR), lupus anticoagulant (LA), factor V G1691A mutation (FV Leiden), prothrombin G20210A mutation, methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C mutations and plasminogen activator inhibitor-1 (PAI-1) gene 5G/4G and 4G/4G polymorphisms.

RESULTS

In IC group were recorded: i) low levels of PC and AT (p = 0.064 and p = 0.022, respectively); ii) low levels of APCR (normal: >2, p = 0.008); iii) high levels of fibrinogen (p = 0.0005); iv) higher number of homozygotes for MTHFR A1298C and C677T mutations (p = 0.061 and p = 0.525 (Pearson chi-square), respectively); v) greater prevalence of 5G/4G and 4G/4G polymorphisms (p = 0.031 (Pearson chi-square)) and vi) higher incidence of LA-positive individuals (p = 0.037, Fischer's exact test). Multivariate analysis was performed to determine the effects of prothrombotic factors in IC. 5G/4G polymorphism of PAI-1 gene (odds ratio (OR) 12.29; 95% confidence interval (CI) 2.26-67.00), APCR (OR 0.089; 95% CI 0.011-0.699) and fibrinogen (OR 1.013; 95% CI 1.003-1.023) were determined as predictors of IC.

CONCLUSIONS

This study suggests that hypercoagulability, hereditary or acquired, plays an essential role in the manifestation of IC.

The Association of Coagulation Factor V (Leiden) and Factor II (Prothrombin) Mutations With Stroke

Background:

Epidemiological studies indicate that over the past forty years, the stroke incidence rates has increased. Factors V and II mutations are established genetic-variant risk factors for venous thrombosis; however, their contribution to stroke is a controversial issue.

Objectives:

This study aimed to investigate the potential association of FV and FII mutations with stroke in an Iranian population.

Patients and Methods:

The study population consisted of 153 patients of different stroke subtypes (except cryptogenic strokes), admitted to Ghaem Hospital, Mashhad, Iran. The control group included 153 age- and sex-matched subjects without a history of cerebrovascular or neurologic diseases. Mutations of FV and FII were determined by using a TaqMan SNP Genotyping technique. The chi-square and Exact Fisher tests were used to analyze the baseline characteristics. Results were as follows: The calculated P-value for sex and diabetes mellitus were 0.907 and 1.000, respectively. The case and control groups were also matched in low density lipoprotein (P = 0.816), high density lipoprotein (P = 0.323), triglyceride (P = 0.846), and total cholesterol (P = 0.079).

Results:

Analysis of the FV showed that none of the study subjects were AA homozygous for this mutation and only 6 heterozygous subjects were detected in the case and control groups. Regarding FII variants, none of the study subjects were AG heterozygous and only 1 AA homozygous was detected in the control group.

Conclusions:

The prevalence of both FV and FII variants are population based. Iran is an ethnically diverse country. Therefore, for a comprehensive analysis of a potential association of FV and/or FII mutations with stroke among Iranian population, epidemiological studies could be conducted among different ethnic groups.

Family History of Myocardial Infarction and Cause-Specific Risk of Myocardial Infarction and Venous Thromboembolism

Background—

A family history of myocardial infarction (FHMI) has been shown to increase the risk of venous thromboembolism (VTE). The mechanism underlying the association remains unclear. Therefore, we aimed to determine the risks of MI and VTE by FHMI using a cause-specific model and to explore whether atherosclerotic risk factors could explain the association between FHMI and VTE in a population-based cohort.

Methods and Results—

The study included 21 624 subjects recruited from the Tromsø Study in 1994 to 1995 and 2001 to 2002. Incident MI and VTE events were registered from date of enrollment to end of follow-up, December 31, 2010. There were 1311 MIs and 428 VTEs during a median follow-up of 15.8 years. FHMI was associated with a 52% increased risk of MI (adjusted hazard ratio, 1.52; 95% confidence interval, 1.35–1.70) and a 26% increased risk of VTE (adjusted hazard ratio, 1.26; 95% confidence interval, 1.02–1.55) in the cause-specific Cox model. Similar results were found using the traditional Cox model. The risk estimates by status of FHMI were highest for unprovoked deep vein thrombosis (adjusted hazard ratio, 1.69; 95% confidence interval, 1.12–2.56), and the risk increased with increasing number of affected relatives. Modifiable atherosclerotic risk factors slightly altered the association between FHMI and MI but had a negligible effect on the association between FHMI and VTE.

Conclusions—

FHMI was associated with increased risk of both MI and VTE in a cause-specific model. Apparently, the association between FHMI and VTE applied to unprovoked deep vein thrombosis and was not explained by modifiable atherosclerotic risk factors.

Platelet glycoprotein IIIa Leu33Pro gene polymorphism and coronary artery disease: A meta-analysis of cohort studies

Great interest has been focused in the last year on genetic predictors of cardiovascular risk. Glycoprotein IIb/IIIa (GP IIb/IIIa), fibrinogen receptor, is the final common pathway for aggregation and a key point for atherothrombosis. A single nucleotide polymorphism of IIIa subunit (Leu33Pro-PlA(1)/PlA(2) allele) has been suggested to increase aggregation and adhesion, however, contrasting reports have been reported so far on its effects on coronary artery disease (CAD). Aim of the current study was to perform a large meta-analysis including cohorts of patients undergoing coronary angiography in order to evaluate whether this polymorphism is associated with coronary artery disease. Literature archives (Pubmed, EMBASE, Cochrane) and main scientific sessions abstracts were scanned for data of consecutive cohorts of patients undergoing coronary angiography, where PlA genotype was assessed. Primary endpoint was the prevalence of CAD. Secondary endpoint was severity of CAD defined as prevalence of multivessel disease (≥2 vessels). Data from seven studies were extracted, including a final number of 6700 patients. Among them 1893 (28.3%) carried the PlA(2) polymorphism, 163 of them in homozygosis. Angiographically defined CAD was present in 3573 (74.3%) PlA(1)/PlA(1) patients and in 1430 (75.5%) PlA(2) carriers. PlA(2) polymorphism was not associated with an increased prevalence of coronary artery disease, (OR [95% CI] = 1.07 [0.95-1.21], p = 0.28, pheterogeneity = 0.39). Similar results were obtained for multivessel disease (OR [95% CI] = 1.07[0.95-1.20], p = 0.27, pheterogeneity = 0.12). Meta-regression analysis demonstrated a significant inverse relationship between the risk of CAD among the PlA(2) carriers and ageing (r = -0.044, (-0.09, -0.0008), p = 0.046). Present meta-analysis demonstrates that 33Leu → Pro substitution of GPIIIa does not influence the prevalence and extent of angiographically defined coronary artery disease in general population, although apparently playing a role among younger patients.

World heart federation expert consensus statement on antiplatelet therapy in east asian patients with ACS or undergoing PCI

Guideline recommendations on the use of dual antiplatelet therapy (DAPT) in patients with acute coronary syndromes and in those undergoing percutaneous coronary intervention (PCI) have been formulated by both the ACC/AHA and the ESC. These recommendations are based primarily on large, phase III, randomized, controlled trials of the P2Y12 inhibitors clopidogrel, prasugrel, and ticagrelor. However, few East Asian patients have been included in the trials to assess the use of these agents, particularly the newer agents prasugrel and ticagrelor. Additionally, an increasing body of data suggests that East Asian patients have differing risk profiles for both thrombophilia and bleeding compared with white patients, and that a different 'therapeutic window' of on-treatment platelet reactivity might be appropriate in East Asian patients. Furthermore, a phenomenon referred to as the 'East Asian paradox' has been described, in which East Asian patients have a similar or even a lower rate of ischaemic events after PCI compared with white patients, despite a higher level of platelet reactivity during DAPT. Recognizing these concerns, the World Heart Federation has undertaken this evidence-based review and produced this expert consensus statement to determine the antiplatelet treatment strategies that are most appropriate for East Asian patients.

Expert consensus document: World Heart Federation expert consensus statement on antiplatelet therapy in East Asian patients with ACS or undergoing PCI

Guideline recommendations on the use of dual antiplatelet therapy (DAPT) in patients with acute coronary syndromes and in those undergoing percutaneous coronary intervention (PCI) have been formulated by both the ACC/AHA and the ESC. These recommendations are based primarily on large, phase III, randomized, controlled trials of the P2Y12 inhibitors clopidogrel, prasugrel, and ticagrelor. However, few East Asian patients have been included in the trials to assess the use of these agents, particularly the newer agents prasugrel and ticagrelor. Additionally, an increasing body of data suggests that East Asian patients have differing risk profiles for both thrombophilia and bleeding compared with white patients, and that a different 'therapeutic window' of on-treatment platelet reactivity might be appropriate in East Asian patients. Furthermore, a phenomenon referred to as the 'East Asian paradox' has been described, in which East Asian patients have a similar or even a lower rate of ischaemic events after PCI compared with white patients, despite a higher level of platelet reactivity during DAPT. Recognizing these concerns, the World Heart Federation has undertaken this evidence-based review and produced this expert consensus statement to determine the antiplatelet treatment strategies that are most appropriate for East Asian patients.

The PlA1/A2 polymorphism of glycoprotein IIIa as a risk factor for myocardial infarction: a meta-analysis

BACKGROUND

The PlA2 polymorphism of glycoprotein IIIa (GPIIIa) has been previously identified as being associated with myocardial infarction (MI), but whether this represents a true association is entirely unclear due to differences in findings from different studies. We performed a meta-analysis to evaluate whether this polymorphism is a risk factor for MI.

METHODS

Electronic databases (MEDLINE and EMBASE) were searched for all articles evaluating genetic polymorphisms of GPIIIa. For studies where acute coronary events were recorded in association with genetic analysis, pooled odds ratios (ORs) were calculated using fixed-effects and random-effects models. The primary outcome measure was MI, and a secondary analysis was also performed for acute coronary syndromes (ACS) more generally.

FINDINGS

57 studies were eligible for statistical analysis and included 17,911 cases and 24,584 controls. Carriage of the PlA2 allele was significantly associated with MI (n = 40,692; OR 1.077, 95% CI 1.024-1.132; p = 0.004) but with significant publication bias (p = 0.040). The degree of association with MI increased with decreasing age of subjects (≤45 years old: n = 9,547; OR 1.205, 95% CI 1.067-1.360; p = 0.003) and with adjustment of data for conventional cardiovascular risk factors (n = 12,001; OR 1.240, 95% CI 1.117-1.376; p<0.001). There was a low probability of publication bias for these subgroup analyses (all p<0.05).

CONCLUSIONS

The presence of significant publication bias makes it unclear whether the association between carriage of the PlA2 allele and MI is true for the total population studied. However for younger subjects, the relative absence of conventional cardiovascular risk factors results in a significant association between carriage of the PlA2 allele and MI.

The Northwick Park Heart Study: evidence from the laboratory

The Northwick Park Heart Study (NPHS) has shown associations of high plasma fibrinogen and factor VII (FVIIc) levels with the risk of death from coronary heart disease (CHD). The finding for fibrinogen has been confirmed in many other studies. Whereas one further study has found a similar prospective association for FVIIc, several have not. Experimental studies have demonstrated the impact that the coagulation activity of fibrinogen and FVIIc have on the progression and phenotype of atherosclerotic lesions. FVIIc-driven thrombin generation and fibrin formation within the vessel wall are important determinants of both plaque (in)stability and atherothrombosis. In blood, local concentrations of FVIIc and thrombin may be sufficient to allow interactions between these serine proteases and protease-activated receptors, to drive cellular inflammatory reactions that further promote these processes. Local fibrinogen concentrations dictate fibrin clot structure and resistance to fibrinolysis. Within the atherosclerotic plaque, coagulation reactions driven by proinflammatory stimuli may initially support lesion stability (as part of wound healing), but, with advanced inflammation, thrombin and fibrin generation diminish because of proteolytic activity contributing to plaque instability. The NPHS findings have proved controversial, but, in the light of current knowledge, a reappraisal of the importance of FVIIc and fibrinogen in atherosclerosis, atherothrombosis and CHD is justified. Hypercoagulability, reflected in turn by thrombin generation capacity, and local concentrations of coagulation proteins, including FVIIc and fibrinogen, is linked to plaque phenotype, and even minute local concentrations of fibrinogen and proteases such as FVIIc may affect thrombin generation capacity.