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

Association between coronary artery stenosis and myocardial injury in patients with acute pulmonary embolism: A case-control study

BACKGROUND

The potential impact of pre-existing coronary artery stenosis (CAS) on acute pulmonary embolism (PE) episodes remains underexplored. This study aimed to investigate the association between pre-existing CAS and the elevation of high-sensitivity cardiac troponin I (hs-cTnI) levels in patients with PE.

METHODS

In this multicenter, prospective case-control study, 88 cases and 163 controls matched for age, sex, and study center were enrolled. Cases were patients with PE with elevated hs-cTnI. Controls were patients with PE with normal hs-cTnI. Coronary artery assessment utilized coronary computed tomographic angiography or invasive coronary angiography. CAS was defined as ≥50% stenosis of the lumen diameter in any coronary vessel >2.0 mm in diameter. Conditional logistic regression was used to evaluate the association between CAS and hs-cTnI elevation.

RESULTS

The percentage of CAS was higher in the case group compared to the control group (44.3% [39/88] vs. 30.1% [49/163]; P = 0.024). In multivariable conditional logistic regression model 1, CAS (adjusted odds ratio [OR], 2.680; 95% confidence interval [CI], 1.243-5.779), heart rate >75 beats/min (OR, 2.306; 95% CI, 1.056-5.036) and N-terminal pro-B type natriuretic peptide (NT-proBNP) >420 pg/mL (OR, 12.169; 95% CI, 4.792-30.900) were independently associated with elevated hs-cTnI. In model 2, right CAS (OR, 3.615; 95% CI, 1.467-8.909) and NT-proBNP >420 pg/mL (OR, 13.890; 95% CI, 5.288-36.484) were independently associated with elevated hs-cTnI.

CONCLUSIONS

CAS was independently associated with myocardial injury in patients with PE. Vigilance towards CAS is warranted in patients with PE with elevated cardiac troponin levels.

Thrombosis risk in single- and double-heterozygous carriers of factor V Leiden and prothrombin G20210A in FinnGen and the UK Biobank

ABSTRACT

The factor V Leiden (FVL; rs6025) and prothrombin G20210A (PTGM; rs1799963) polymorphisms are 2 of the most well-studied genetic risk factors for venous thromboembolism (VTE). However, double heterozygosity (DH) for FVL and PTGM remains poorly understood, with previous studies showing marked disagreement regarding thrombosis risk conferred by the DH genotype. Using multidimensional data from the UK Biobank (UKB) and FinnGen biorepositories, we evaluated the clinical impact of DH carrier status across 937 939 individuals. We found that 662 participants (0.07%) were DH carriers. After adjustment for age, sex, and ancestry, DH individuals experienced a markedly elevated risk of VTE compared with wild-type individuals (odds ratio [OR] = 5.24; 95% confidence interval [CI], 4.01-6.84; P = 4.8 × 10-34), which approximated the risk conferred by FVL homozygosity. A secondary analysis restricted to UKB participants (N = 445 144) found that effect size estimates for the DH genotype remained largely unchanged (OR = 4.53; 95% CI, 3.42-5.90; P < 1 × 10-16) after adjustment for commonly cited VTE risk factors, such as body mass index, blood type, and markers of inflammation. In contrast, the DH genotype was not associated with a significantly higher risk of any arterial thrombosis phenotype, including stroke, myocardial infarction, and peripheral artery disease. In summary, we leveraged population-scale genomic data sets to conduct, to our knowledge, the largest study to date on the DH genotype and were able to establish far more precise effect size estimates than previously possible. Our findings indicate that the DH genotype may occur as frequently as FVL homozygosity and may confer a similarly increased risk of VTE.

The Etiology of the Thrombotic Phenomena Involved in the Process of Coronary Artery Disease-What Is the Role of Thrombophilic Genes in the Development of This Pathology?

Cardiovascular diseases, among which includes coronary artery disease, represent one of the most important causes of mortality and morbidity worldwide. Research aimed at determining the risk factors involved recognizes a group of "traditional" risk factors, but also more recent studies identified over 100 "novel" ones which may have a role in the disease. Among the latter is the thrombophilia profile of a patient, a pathology well-established for its involvement in venous thromboembolism, but with less studied implications in arterial thrombosis. This paper reviews the literature, explaining the pathophysiology of the thrombophilia causes associated most with coronary thrombosis events. Results of several studies on the subject, including a meta-analysis with over 60,000 subjects, determined the significant involvement of factor V Leiden, prothrombin G20210A mutation, plasminogen activator inhibitor-1 and antiphospholipid syndrome in the development of coronary artery disease. The mechanisms involved are currently at different stages of research, with some already established and used as therapeutic targets.

Factor V Leiden, prothrombin, MTHFR, and PAI-1 gene polymorphisms in patients with arterial disease: A comprehensive systematic-review and meta-analysis

INTRODUCTION

The role of inherited thrombophilia in arterial disease is uncertain. We performed a systematic-review and meta-analysis of inherited thrombophilia in cerebrovascular (CVD), coronary heart (CHD), and peripheral artery disease (PAD) patients.

MATERIALS AND METHODS

MEDLINE and EMBASE were searched up to February 2022. Pooled prevalences (PPs) and odds ratios (ORs) with 95 % confidence intervals (95%CI) were calculated in a random-effects model. Factor V Leiden (G1691A), prothrombin (G20210A), MTHFR C677T/A1298C and PAI-1 4G/5G were evaluated.

RESULTS

377 studies for 98,186 patients (32,791 CVD, 62,266 CHD, 3129 PAD) and 108,569 controls were included. Overall, 37,249 patients had G1691A, 32,254 G20210A, 42,546 MTHFR C677T, 8889 MTHFR A1298C, and 19,861 PAI-1 4G/5G gene polymorphisms. In CVD patients, PPs were 6.5 % for G1691A, 3.9 % for G20210A, 56.4 % for MTHFR C677T, 51.9 % for MTHFR A1298C, and 77.6 % for PAI-1. In CHD, corresponding PPs were 7.2 %, 3.8 %, 52.3 %, 53.9 %, and 76.4 %. In PAD, PPs were 6.9 %, 4.7 %, 55.1 %, 52.1 %, and 75.0 %, respectively. Strongest ORs in CVD were for homozygous G1691A (2.76; 95 %CI, 1.83-4.18) and for homozygous G20210A (3.96; 95 %CI, 2.05-7.64). Strongest ORs in CHD were for homozygous G1691A (OR 1.68; 95%CI, 1.02-2.77) and G20210A (heterozygous 1.49 95%CI, 1.22-1.82; homozygous 1.54 95%CI, 0.79-2.99). The OR for PAI-1 4G/4G in PAD was 5.44 (95%CI, 1.80-16.43). Specific subgroups with higher PPs and ORs were identified according to age and region.

CONCLUSIONS

Patients with arterial disease have an increased prevalence and odds of having some inherited thrombophilia. Some thrombophilia testing may be considered in specific subgroups of patients.

Laboratory Evaluation of Antithrombin, Protein C, and Protein S

Thrombophilia is a complex disease process, clinically manifesting in various forms of venous thromboembolism. Although both genetic and acquired (or environmental) risks factors have been reported, the presence of a genetic defect (antithrombin [AT], protein C [PC], protein S [PS]) is considered three of the major contributing factors of thrombophilia. The presence of each of these risk factors can be established by clinical laboratory analysis; however, the clinical provider and laboratory personnel must understand the testing limitations and shortcomings associated with the assays for these factors to be able to ensure an accurate diagnosis. This article will describe the major pre-analytical, analytical, and post-analytical issues associated with the various types of assays and discuss evidence-based algorithms for analyzing AT, PC, and PS in plasma.

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

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

Massive Left Ventricular Thrombus After ST-Segment Elevation Myocardial Infarction in a Young Man With Factor V Leiden

•

STEMI caused by obstructive CAD is uncommon in young adults.

•

Factor V Leiden and antipsychotic medication use may increase the risk for ACS.

•

LV thrombus is a common complication of acute anterior STEMI.

•

TTE is the most common imaging modality used in diagnosing LV thrombus.

•

Anticoagulation therapy for LV thrombus should be individually tailored.

Venous thromboembolism with renal infarct due to paradoxical embolism

Paradoxical thromboembolism has variable presentation depending on site of embolisation. An African-American man in his 40s presented with severe abdominal pain, watery stools and exertional dyspnoea. At presentation, he was tachycardic and hypertensive. Labwork showed elevated creatinine with unknown baseline. Urinalysis showed pyuria. A CT scan was unremarkable. He was admitted with working diagnosis of acute viral gastroenteritis and prerenal acute kidney injury and supportive care was instituted. On day 2, the pain migrated to left flank. Renal artery duplex ruled out renovascular hypertension but showed a lack of distal renal perfusion. MRI confirmed a renal infarct with renal artery thrombosis. Transoesophageal echocardiogram confirmed a patent foramen ovale. Simultaneous arterial and venous thrombosis require hypercoagulable workup, including investigation for malignancy, infection or thrombophilia. Rarely, venous thromboembolism can directly cause arterial thrombosis by 'paradoxical thromboembolism'. Given the rarity of renal infarct, high index of clinical suspicion is necessary.

Dilemmas in hematology: consults in patients with arterial thrombosis

Arterial thrombotic events, particularly ischemic stroke and myocardial infarction, are common, and mostly occur due to atherosclerotic disease or arrhythmias. The diagnosis and management of the majority of such events occurs without the involvement of a hematologist, following established guidelines or pathways. In this review, we discuss 3 scenarios in which optimal management is less certain. These scenarios concern patients with a left ventricular thrombus, in whom the duration and choice of anticoagulant has been debated, patients with ischemic stroke and a patent foramen ovale, in whom the role of patent foramen ovale closure requires careful consideration, and the role of thrombophilia testing in young patients after a stroke or myocardial infarction, which remains an area of contention. We consider the available evidence and published guidelines in order to provide a practical, evidence-based approach to these 3 clinical scenarios.

Factor V Leiden but not the factor II 20210G>A mutation is a risk factor for premature coronary artery disease: a case-control study in Iran

Background

Factor V Leiden (FVL) and factor II c.∗97G>A (rs1799963) are genetic risk factors for venous thromboembolism. Their contribution to coronary artery disease (CAD) is less clear.

Objectives

This study aimed to investigate the association between FVL, rs1799963, and premature CAD in Iranians.

Methods

We performed a genetic case-control study of 944 cases and 1081 controls from the premature CAD Milano-Iran study, including patients aged 18-55 (female) and 18-45 years (male) who underwent coronary angiography at the Tehran Heart Centre (Iran) in 2004-2011. Cases had luminal stenosis ≥50% in at least 1 main coronary artery or branch. Controls were age- and sex-matched with no CAD history. FVL and rs1799963 were genotyped using TaqMan SNP genotyping assays. Association was tested by logistic regression adjusted for matching factors and ethnicity. Effect modification by sex and cardiovascular risk factors (metabolic [obesity, hypertension, hyperlipidemia, and diabetes], and smoking) was assessed.

Results

The risk of premature CAD was increased by 50% in FVL carriers (adjusted odds ratio [adjOR] 1.54 [95% CI, 0.95-2.48]) and slightly reduced in rs1799963 carriers (adjOR 0.71 [95% CI, 0.40-1.27]). These effects were more pronounced in women than men (FVL, adjOR 1.66 vs 1.25; rs1799963, adjOR 0.60 vs 1.07). The risk of premature CAD was substantially increased in carriers of FVL with at least 1 metabolic risk factor compared with noncarriers without metabolic risk factors (adjOR 25.14 [95% CI, 12.51-50.52]).

Conclusion

FVL but not FII rs1799963 was associated with an increased risk of CAD in young Iranians. This risk increased considerably when combined with metabolic cardiovascular risk factors.

Laboratory Evaluation of Thrombophilia

Venous thromboembolism (VTE) occurs typically in the veins of the lower extremities and/or as pulmonary embolism. There is a myriad of causes of VTE ranging from provoked causes (e.g., surgery, cancer) to unprovoked causes (e.g., inherited abnormalities) or multiple factors that combine to initiate the cause. Thrombophilia is a complex, multi-factorial disease that may result in VTE. The mechanism(s) and causes of thrombophilia are complex and not completely understood. In healthcare today, only some answers about the pathophysiology, diagnosis, and prevention of thrombophilia have been elucidated. The laboratory analysis for thrombophilia is not consistently applied, and has changed over time, but remains varied by providers and laboratories as well. Both groups must establish harmonized guidelines for patient selection and appropriate conditions for analysis of inherited and acquired risk factors. This chapter discusses the pathophysiology of thrombophilia, and evidence-based medicine guidelines discuss the optimum laboratory testing algorithms and protocols for selection and analyzing VTE patients to ensure a cost-effective use of limited resources.

Microsurgical Breast Reconstruction in Patients with Disorders of Hemostasis: Perioperative Risks and Management

BACKGROUND

Surgical and technological advances have resulted in the widespread adoption of microsurgical breast reconstruction. Many comorbidities that potentially might impair vasculature and wound healing are no longer considered contraindications for these procedures. However, some uncertainty still prevails regarding the perioperative management of patients with disorders of hemostasis.

METHODS

The authors combined a literature review with a retrospective chart review of patients with disorders of hemostasis who had undergone microsurgical breast reconstruction at the senior author's (J.F.) center between 2015 to 2020. Several disorders associated with thrombotic and/or hemorrhagic complications were identified, and a standardized risk assessment and management strategy was developed in cooperation with a hematologist.

RESULTS

Overall, 10 studies were identified comprising 29 patients who had a defined disorder of hemostasis and underwent microsurgical breast reconstruction. Seventeen microsurgical breast reconstructions were performed on 11 patients at the senior author's (J.F.) center. High factor VIII levels, heterozygous factor V Leiden, and heterozygous prothrombin mutation G20210A were the most common genetic or mixed genetic/acquired thrombophilic conditions. As expected, hereditary antithrombin, protein C, or protein S deficiencies were rare. Among hemorrhagic disorders, thrombocytopenia, platelet dysfunction, and von Willebrand disease or low von Willebrand factor levels were those factors most frequently associated with increased perioperative bleeding.

CONCLUSIONS

Patients should be screened for elevated risk of thrombosis or bleeding before undergoing microsurgical breast reconstruction, and positive screening should prompt a complete hematologic evaluation. Interdisciplinary management of these disorders with a hematologist is essential to minimize risks and to obtain optimal reconstructive results.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, IV.

Systematic Review and Meta-Analysis of the Susceptibility of ABO Blood Groups to Venous Thromboembolism in Individuals with Factor V Leiden

A limited number of studies investigated the association between the ABO blood groups and the incidence of venous thromboembolism in individuals with Factor V Leiden; however, discordant findings were reported. Consequently, this systematic review and meta-analysis aimed to evaluate the existing evidence on the susceptibility of the ABO blood group to venous thromboembolism in individuals with Factor V Leiden. All English-published articles on the Web of Science, Scopus, PubMed, EMBASE, and Google Scholar were comprehensively and systematically searched by the author without a time or region limit. Four studies were included in the qualitative synthesis and meta-analysis after the removal of studies that were not eligible. According to the analyses of the fixed and random effects, the point estimates of the effect size and the 95% confidence interval were 0.416 (95% CI: 0.397−0.435) and 0.392 (95% CI: 0.288−0.507), respectively. In contrast, the homogeneity test (Q value) reveals that blood group data distributions have a heterogenous structure (Q = 432.187; p-value < 0.001). The pooled event rates and the 95% CIs for the A, AB, B, and O-blood groups were 0.518 (95% CI: 0.411−0.622), 0.592 (95% CI: 0.495−0.683), 0.205 (95% CI: 0.041−0.612), and 0.283 (95% CI: 0.247−0.322), respectively. According to the findings, people with Factor V Leiden with blood group AB are more likely to develop venous thromboembolism than those with blood groups A, O, and B. The overall statistical significance of the ABO blood group’s susceptibility to venous thromboembolism in individuals with Factor V Leiden was <0.001 (pooled p-value). In conclusion, the current meta-analysis provides an additional indication that blood group AB individuals with Factor V Leiden are at higher risk of developing venous thromboembolism, and blood type B is connected to a lower risk of developing venous thromboembolism.

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

Introduction

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

Methods

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

Results

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

Conclusions

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

Coagulation Factor XIII Val34Leu Polymorphism in the Prediction of Premature Cardiovascular Events-The Results of Two Meta-Analyses

Background: Polymorphisms within the gene that encodes for coagulation factor XIII (FXIII) have been suggested to be involved in the pathogeneses of ischemic stroke (IS) and myocardial infarction (MI). The Val34Leu polymorphism is one of the most commonly analysed FXIII polymorphisms. However, studies on the role of the Val34Leu polymorphism in the aetiology of vascular diseases often show contradictory results. In the present meta-analysis, we aimed to pool data from available articles to assess the relationship between the FXIII Val34Leu polymorphism and the susceptibilities to IS of undetermined source and premature MI in patients aged below 55 years. Methods: We searched databases (PubMed, Embase, Google Scholar, SciELO, and Medline) using specific keywords (the last search was in January 2022). Eventually, 18 studies (627 cases and 1639 controls for IS; 2595 cases and 4255 controls for MI) met the inclusion criteria. Data were analysed using RevMan 5.4 and StatsDirect 3 link software. The relation between Val34Leu polymorphism and disease was analysed in five genetic models, i.e., dominant, recessive, additive, heterozygous, and allelic. Results: No relation between Val34Leu polymorphism and IS in young adults was observed in all analysed genetic models. For premature MI, significant pooled OR was found between the carrier state of the Leu allele (Val/Leu + Leu/Leu vs. Val/Val) and a lack of MI, suggesting its protective role (OR = 0.80 95%CI 0.64–0.99, p = 0.04). A similar finding was observed for the heterozygous model in MI (Val/Leu vs. Val/Val) (OR = 0.77 95%CI 0.61–0.98, p = 0.03). No relation was found for the recessive, additive, and allelic models in MI. Conclusions: In the population of young adults, no positive correlation was found between the FXIII Val34Leu polymorphism and IS of undetermined source in any of the analysed genetic models. In turn, the carrier state of the 34Leu allele as well as FXIII heterozygotes themselves were found to play a protective role in relation to premature MI.

Associations of Hemostatic Variables with Cardiovascular Disease and Total Mortality: The Glasgow MONICA Study

The associations of plasma levels of hemostatic factors, other than fibrinogen, with risks of cardiovascular disease (CVD) and all-cause mortality are not well defined. In two phases of the Glasgow MONICA study, we assayed coagulation factors (VII, VIII, IX, and von Willebrand factor), coagulation inhibitors (antithrombin, protein C, protein S), coagulation activation markers (prothrombin fragment 1 + 2, thrombin–antithrombin complexes, D-dimer), and the fibrinolytic factors, tissue plasminogen activator (t-PA) antigen and plasminogen activator inhibitor type 1. Over 15 to 20 years, we followed up between 382 and 1,123 men and women aged 30 to 74 years, without baseline CVD, for risks of CVD and mortality. Age- and sex-adjusted hazard ratios (HRs) for CVD (top third vs bottom third) were significant only for factor VIII (1.30; 95% confidence interval [CI], 1.06–1.58) and factor IX (1.18; 95% CI, 1.01–1.39); these HRs were attenuated by further adjustment for CVD risk factors: 1.17 (95% CI, 0.94–1.46) and 1.07 (95% CI, 0.92–1.25), respectively. In contrast, factor VIII (HR, 1.63; 95% CI, 1.35–1.96), D-dimer (HR, 2.34; 95% CI, 1.26–4.35), and t-PA (HR, 2.81; 95% CI, 1.43–5.54) were strongly associated with mortality after full risk factor adjustment. Further studies, including meta-analyses, are required to assess the associations of these hemostatic factors with the risks of stroke and heart disease and causes of mortality.

Comparison of Ticagrelor With Clopidogrel in East Asian Patients With Acute Coronary Syndrome: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

ABSTRACT

The risk of bleeding is high in East Asians, whether East Asian patients with acute coronary syndrome choose ticagrelor or clopidogrel is still controversial. In this study, PubMed, EMBASE, Cochrane Library database, and other sources were systematically searched. The primary efficacy outcome was all-cause death, the primary safety outcomes were any bleeding, PLATO major bleeding, and fatal bleeding. The secondary outcomes included vascular-cause death, myocardial infarction, stent thrombosis, stroke, and dyspnea. A total of 8 randomized controlled trials with 3597 patients met inclusion criteria. Compared with clopidogrel, ticagrelor had significantly higher incidence of any bleeding [risk ratio (RR), 1.63; 1.33-1.99; P < 0.00001], PLATO major bleeding (RR 1.56; 1.15-2.12; P = 0.004), and dyspnea (RR 2.60; 1.68-4.00; P < 0.00001). However, ticagrelor was associated with a significantly reduced risk of stent thrombosis (RR 0.42; 0.19-0.92; P = 0.03). There was no significant difference in the risk of all-cause death (RR 0.87; 0.64-1.24; P = 0.44), fatal bleeding (RR 2.49; 0.79-7.86; P = 0.12), vascular-cause death (RR 0.88; 1.60-0.30; P = 0.52), myocardial infarction (RR 0.89; 0.65-1.23; P = 0.49), and stroke (RR 0.84; 0.47-1.50; P = 0.56) between the 2 groups. The present findings demonstrated that ticagrelor was associated with a higher risk of any bleeding, PLATO major bleeding, and dyspnea compared with clopidogrel in East Asian patients with acute coronary syndrome. However, it significantly reduced the risk of stent thrombosis. (Registered by PROSPERO, CRD42021255215).

ASSOCIATIONS OF HAEMOSTATIC VARIABLES WITH CARDIOVASCULAR DISEASE AND TOTAL MORTALITY - THE GLASGOW MONICA STUDY

The associations of plasma levels of hemostatic factors, other than fibrinogen, with risks of cardiovascular disease (CVD) and all-cause mortality are not well defined. In two phases of the Glasgow MONICA study, we assayed coagulation factors (VII, VIII, IX, and von Willebrand factor), coagulation inhibitors (antithrombin, protein C, protein S), coagulation activation markers (prothrombin fragment 1 + 2, thrombin–antithrombin complexes, D-dimer), and the fibrinolytic factors, tissue plasminogen activator (t-PA) antigen and plasminogen activator inhibitor type 1. Over 15 to 20 years, we followed up between 382 and 1,123 men and women aged 30 to 74 years, without baseline CVD, for risks of CVD and mortality. Age- and sex-adjusted hazard ratios (HRs) for CVD (top third vs bottom third) were significant only for factor VIII (1.30; 95% confidence interval [CI], 1.06–1.58) and factor IX (1.18; 95% CI, 1.01–1.39); these HRs were attenuated by further adjustment for CVD risk factors: 1.17 (95% CI, 0.94–1.46) and 1.07 (95% CI, 0.92–1.25), respectively. In contrast, factor VIII (HR, 1.63; 95% CI, 1.35–1.96), D-dimer (HR, 2.34; 95% CI, 1.26–4.35), and t-PA (HR, 2.81; 95% CI, 1.43–5.54) were strongly associated with mortality after full risk factor adjustment. Further studies, including meta-analyses, are required to assess the associations of these hemostatic factors with the risks of stroke and heart disease and causes of mortality.

Antithrombotic Therapy After Acute Coronary Syndromes or Percutaneous Coronary Interventions in East Asian Populations

Because guidelines and recommendations in response to multiple randomized clinical trials (RCTs) of new therapies undergo rapid changes, antithrombotic therapies for patients after acute coronary syndrome, or percutaneous coronary intervention, are becoming more complex in daily clinical practice. The proportion of Asian populations enrolled in landmark RCTs is substantially low, which limits the direct application of trial findings into clinical practice in Asian countries. Moreover, compared with Caucasian patients, East Asian patients are considered to have a different ischemia/bleeding propensity in response to antithrombotic therapy, known as the "East Asian paradox" (ie, more bleeding events but fewer thromboembolic events). Coincident with consecutive RCTs in Western populations to optimize antithrombotic strategies, several such studies have now been conducted in East Asian cohorts. Herein, we provide a comprehensive summary of the key RCTs in this regard and propose future directions and perspectives for optimal antithrombotic therapies in East Asian patients.

Cryptogenic Stroke in the Young: Role of Candidate Gene Polymorphisms in Indian Patients with Ischemic Etiology

CONTEXT

Strokes that remain without a definite cause even after an extensive workup, termed cryptogenic strokes, constitute up to 30-40% of ischemic strokes (ISs) in the young. Some of them can have a genetic basis. However, the well-established genetic causes account for only a small percentage of these cases.

AIM

To evaluate the association of cryptogenic young IS with 16 candidate gene polymorphisms.

SETTINGS AND DESIGN

A case-control study with cryptogenic young IS patients (South and North Indians; n = 105) and age, sex, and ethnicity-matched controls (n = 215).

SUBJECTS AND METHODS

Genotyping was carried out by PCR-RFLP method using DNA extracted from the blood.

STATISTICAL ANALYSIS USED

Association of the genotypes with the disease was studied using Chi-square test.

RESULTS

MTHFR rs1801133 and KNG1 rs710446 showed significant statistical association with cryptogenic young IS (P = 0.0261 and 0.0157, respectively) in the Indian population. Significant association of KNG1 rs710446 (P 0.0036) and FXII rs1801020 (P 0.0376) with cryptogenic young stroke in South Indian males, SERPINC1 rs2227589 in South Indian female patients (P = 0.0374), and CYP4V2 rs13146272 in North Indian males (P = 0.0293) was observed.

CONCLUSIONS

Our study indicates that in the Indian population MTHFR rs1801133, KNG rs710446, FXII rs1801020, SERPINC1 rs2227589, CYP4V2 rs13146272, and FXIII V34L may be significant risk factors for cryptogenic IS in the young. In addition, ethnicity and gender play a significant role. Further studies with larger sample size are required to completely establish these polymorphisms as risk factors for cryptogenic IS in young Indians.

Quantile-specific heritability of plasminogen activator inhibitor type-1 (PAI-1, aka SERPINE1) and other hemostatic factors

BACKGROUND

Plasminogen activator inhibitor type-1 (PAI-1, aka SERPINE1) is a moderately heritable glycoprotein that regulates fibrin clot dissolution (fibrinolysis).

OBJECTIVES

Test whether the heritabilities (h2 ) of PAI-1 and other hemostatic factors are constant throughout their distribution or whether they are quantile-specific (i.e., a larger or smaller h2 depending on whether their concentrations are high or low).

METHODS

Quantile regression was applied to 5606 parent-offspring pairs and 5310 full siblings of the Framingham Heart Study. Quantile-specific heritability was estimated from the parent-offspring regression slope (βPO , h2  = 2βPO /(1+rspouse )) and the full-sib regression slope (βFS , h2  = {(1+8rspouse βFS )0.5 -1}/(2rspouse )).

RESULTS

Heritability (h2  ± SE) increased significantly with increasing percentiles of the offspring's age- and sex-adjusted PAI-1 distribution when estimated from βPO (plinear trend  = 0.0001): 0.09 ± 0.02 at the 10th, 0.09 ± 0.02 at the 25th, 0.16 ± 0.02 at the 50th, 0.29 ± 0.04 at the 75th, and 0.26 ± 0.08 at the 90th percentile of the PAI-1 distribution, and when estimated from βFS (plinear trend  = 6.5x10-7 ). There was no significant evidence for quantile-specific heritability for factor VII (plinear trend  = 0.35), D-dimer (plinear trend  = 0.08), tPA (plinear trend  = 0.74), or von Willebrand factor (plinear trend  = 0.79).

CONCLUSION

Higher mean plasma PAI-1 antigen concentrations tend to accentuate genetic effects (quantile-dependent expressivity), which is consistent with the greater reported differences in PAI-1 concentrations between rs1799889 SERPINE1 (4G/5G) genotypes in patients with osteonecrosis, meningococcal sepsis, obesity, prior myocardial infarction, deep vein thrombosis, and polycystic ovarian syndrome than in healthy controls. It is also consistent with the greater increases in PAI-1 concentrations in 4G-allele carriers than 5G/5G homozygotes following fibrinolytic treatment, low-salt intake, and high saturated fat intake.

Factor V Leiden and the Risk of Bleeding in Patients With Acute Coronary Syndromes Treated With Antiplatelet Therapy: Pooled Analysis of 3 Randomized Clinical Trials

Background

Whether factor V Leiden is associated with lower bleeding risk in patients with acute coronary syndromes using (dual) antiplatelet therapy has yet to be investigated.

Methods and Results

We pooled data from 3 randomized clinical trials, conducted in patients with acute coronary syndromes, with adjudicated bleeding outcomes. Cox regression models were used to obtain overall and cause‐specific hazard ratios (HRs) to account for competing risk of atherothrombotic outcomes (ie, composite of ischemic stroke, myocardial infarction, and cardiovascular death) in each study. Estimates from the individual studies were pooled using fixed effect meta‐analysis. The 3 studies combined included 17 623 patients of whom 969 (5.5%) were either heterozygous or homozygous (n=23) carriers of factor V Leiden. During 1 year of follow‐up, a total of 1289 (7.3%) patients developed major (n=559) or minor bleeding. Factor V Leiden was associated with a lower risk of combined major and minor bleeding (adjusted cause‐specific HR, 0.75; 95% CI, 0.56–1.00; P=0.046; I²=0%) but a comparable risk of major bleeding (adjusted cause‐specific HR, 0.93; 95% CI, 0.62–1.39; P=0.73; I²=0%). Adjusted pooled cause‐specific HRs for the association of factor V Leiden with atherothrombotic events alone and in combination with bleeding events were 0.75 (95% CI, 0.55–1.02; P=0.06; I²=0%) and 0.75 (95% CI, 0.61–0.92; P=0.007; I²=0%), respectively.

Conclusions

Given that the lower risk of bleeding conferred by factor V Leiden was not counterbalanced by a higher risk of atherothrombotic events, these findings warrant future assessment for personalized medicine such as selecting patients for extended or intensive antiplatelet therapy.

Hypercoagulable State in COPD-A Comprehensive Literature Review

Chronic Obstructive Pulmonary Disease (COPD) is a chronic inflammatory disease with multisystemic manifestations. Studies either held on stable disease patients or during exacerbations have demonstrated that COPD is strongly related to venous thromboembolism and cardiovascular events. The aim of the present review of the literature was to provide an in-depth overview regarding the alterations of coagulation factors and prothrombotic changes generated in patients with stable COPD and during COPD exacerbations.

Factor V Leiden Does Not Modify the Phenotype of Acute Coronary Syndrome or the Extent of Myocardial Necrosis

Background The prothrombotic defect factor V Leiden (FVL) may confer higher risk of ST-segment-elevation myocardial infarction (STEMI), compared with non-ST-segment-elevation acute coronary syndrome, and may be associated with more myocardial necrosis caused by higher thrombotic burden. Methods and Results Patients without history of cardiovascular disease were selected from 2 clinical trials conducted in patients with acute coronary syndrome. FVL was defined as G-to-A substitution at nucleotide 1691 in the factor V (factor V R506Q) gene. Odds ratios were calculated for the association of FVL with STEMI adjusted for age and sex in the overall population and in the subgroups including sex, age (≥70 versus <70 years), and traditional cardiovascular risk factors. The peak biomarker levels (ie, creatine kinase-myocardial band and high-sensitivity troponin I or T) after STEMI were contrasted between FVL carriers and noncarriers. Because of differences in troponin assays, peak high-sensitivity troponin levels were converted to a ratio scale. The prevalence of FVL mutation was comparable in patients with STEMI (6.0%) and non-ST-segment-elevation acute coronary syndrome (5.8%). The corresponding sex- and age-adjusted odds ratio was 1.06 (95% CI, 0.86-1.30; P=0.59) for the association of FVL with STEMI. Subgroup analysis did not show any differences. In patients with STEMI, neither the median peak creatine kinase-myocardial band nor the peak high-sensitivity troponin ratio showed any differences between wild-type and FVL carriers (P for difference: creatine kinase-myocardial band=0.33; high sensitivity troponin ratio=0.54). Conclusions In a general population with acute coronary syndrome, FVL did not discriminate between a STEMI or non-ST-segment-elevation acute coronary syndrome presentation and was unrelated to peak cardiac necrosis markers in patients with STEMI. Registration URL: https://www.clinicaltrials.gov; Unique identifiers: NCT00391872 and NCT01761786.

How I treat unexplained arterial thrombosis

Most arterial thrombotic events have a clear atherosclerotic or cardioembolic etiology, but hematologists are frequently asked to assist in the diagnosis and management of a patient with a nonatherosclerotic and noncardioembolic arterial event, referred to here as an unexplained arterial thrombosis. Because there is an assorted list of factors that can precipitate an arterial event, we present a systematic diagnostic approach to ensure consideration of not only primary hypercoagulable disorders, but also pro-thrombotic medications or substances, vascular and anatomic abnormalities, and undiagnosed systemic disorders, such as malignancy and autoimmune diseases. We also review existing literature of the role of hypercoagulable disorders in arterial thrombosis and discuss our approach to thrombophilia workup in patients after an unexplained arterial event. We conclude with 3 representative cases to both illustrate the application of the outlined diagnostic schema and discuss common management considerations, specifically the selection of anticoagulation vs antiplatelet therapy for secondary prevention.

Ethnic Difference of Thrombogenicity in Patients with Cardiovascular Disease: a Pandora Box to Explain Prognostic Differences

Arterial and venous atherothrombotic events are finely regulated processes involving a complex interplay between vulnerable blood, vulnerable vessel, and blood stasis. Vulnerable blood ('thrombogenicity') comprises complex interactions between cellular components and plasma factors (inflammatory, procoagulant, anticoagulant, and fibrinolytic factors). The extent of thrombogenicity may determine the progression of atheroma and the clinical manifestation of atherothrombotic events, with the highest thrombogenicity in African Americans and lowest in East Asians. Inherent thrombogenicity may influence clinical efficacy and safety of specific antithrombotic treatments in high-risk patients, which may in part explain the observation that East Asian patients have reduced anti-ischemic benefits and elevated bleeding risk with antithrombotic therapy compared to Caucasian patients. In this review, we discuss available evidence regarding the racial differences in thrombogenicity and its impact on clinical outcomes among patients with atherosclerotic cardiovascular disease.

Implications and characteristics of high bleeding risk in East Asian patients undergoing percutaneous coronary intervention: Start with what is right rather than what is acceptable

Recent advances in percutaneous coronary intervention (PCI) technology and medication have changed the main focus of PCI from preventing ischemic to preventing bleeding events. Bleeding risk assessment is essential for preventing bleeding. Several types of assessment tools have been established, but they are heterogeneous, making interpretation, generalization, and comparison between trials difficult. In 2019, the Academic Research Consortium (ARC) introduced a new consensus document with 20 criteria to define high bleeding risk (HBR). The applicability of the ARCHBR criteria were subsequently investigated, and 4 studies have already demonstrated wide applicability worldwide, including in Japan. Nevertheless, it hase been suggested that bleeding risk is higher in people from East Asian countries than in people from Western countries. Patients with HBR have a 3-fold higher risk of major bleeding, and in Japan approximately 50% of patients undergoing PCI have HBR. In addition, patients with overlapping factors, such as older age, renal disease, and anemia, are at increased risk of bleeding, and each additional factor further increases the risk. In Japanese patients undergoing PCI, in addition to the ARC-HBR criteria, low body weight, heart failure, and peripheral arterial disease are high-risk subsets for bleeding. The addition of these factors to the ARCHBR criteria increases the prevalence of HBR in Japanese patients to 58% and improves the sensitivity of diagnostic evaluations. The additional factors are clinically important because they are often encountered in everyday practice, and Japan's newly updated guideline has adopted them as criteria for HBR. Studies found a temporal trend over the past 20 years of a gradual and consistent increase of bleeding risk. This finding contrasts with improved outcomes in people at risk of ischemic and thrombotic events. Therefore, further research is needed to eliminate the risk of bleeding while maintaining the efficacy of antithrombotic therapy after PCI.

The East Asian Paradox: An Updated Position Statement on the Challenges to the Current Antithrombotic Strategy in Patients with Cardiovascular Disease

East Asian patients have reduced anti-ischemic benefits and increased bleeding risk during antithrombotic therapies compared with Caucasian patients. As potent P2Y₁₂ receptor inhibitors (e.g., ticagrelor and prasugrel) and direct oral anticoagulants are commonly used in current daily practice, the unique risk-benefit trade-off in East Asians has been a topic of emerging interest. In this article, we propose updated evidence and future directions of antithrombotic treatment in East Asian patients.

Viscoelastic properties of clot formation and their clinical impact in East Asian versus Caucasian patients with stable coronary artery disease: a COMPARE-RACE analysis

Compared with Caucasian patients, East Asian patients with coronary artery disease (CAD) have demonstrated better clinical outcomes. We sought to compare the viscoelastic properties of clot formation and their impact on clinical outcomes in East Asian vs. Caucasian patients. We analyzed age- and sex-matched East Asian and Caucasian patients with stable CAD (n = 249 each). Viscoelastic properties of clot formation were assessed with thromboelastography (TEG), and 3-year clinical outcomes were recorded. Major adverse cardiovascular events (MACE) were defined as a composite of cardiovascular death, myocardial infarction, or stroke. Compared with Caucasians, East Asians showed lower platelet-fibrin clot strength (PFCS) (maximum amplitude [MA]: 61.8 ± 7.9 vs. 65.4 ± 5.0 mm, p < 0.001). In a multivariate analysis, high PFCS (defined as MA ≥ 68 mm) was significantly associated with MACE occurrence (odds ratio 6.27, 95% CI 2.41 to 16.30, p < 0.001). East Asians vs. Caucasians had lower prevalence of high PFCS (odds ratio 0.50, 95% CI 0.27 to 0.93, p = 0.028). In conclusion, this is the first study to demonstrate different viscoelastic properties of clot between East Asian and Caucasian patients with stable CAD. The platelet-fibrin clot strength was significantly associated with MACE in these patients and was significantly lower in East Asians. Future studies are warranted to further explore the mechanistic explanation and clinical importance of these findings.

Association of Factor V Leiden With Subsequent Atherothrombotic Events: A GENIUS-CHD Study of Individual Participant Data

BACKGROUND

Studies examining the role of factor V Leiden among patients at higher risk of atherothrombotic events, such as those with established coronary heart disease (CHD), are lacking. Given that coagulation is involved in the thrombus formation stage on atherosclerotic plaque rupture, we hypothesized that factor V Leiden may be a stronger risk factor for atherothrombotic events in patients with established CHD.

METHODS

We performed an individual-level meta-analysis including 25 prospective studies (18 cohorts, 3 case-cohorts, 4 randomized trials) from the GENIUS-CHD (Genetics of Subsequent Coronary Heart Disease) consortium involving patients with established CHD at baseline. Participating studies genotyped factor V Leiden status and shared risk estimates for the outcomes of interest using a centrally developed statistical code with harmonized definitions across studies. Cox proportional hazards regression models were used to obtain age- and sex-adjusted estimates. The obtained estimates were pooled using fixed-effect meta-analysis. The primary outcome was composite of myocardial infarction and CHD death. Secondary outcomes included any stroke, ischemic stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality.

RESULTS

The studies included 69 681 individuals of whom 3190 (4.6%) were either heterozygous or homozygous (n=47) carriers of factor V Leiden. Median follow-up per study ranged from 1.0 to 10.6 years. A total of 20 studies with 61 147 participants and 6849 events contributed to analyses of the primary outcome. Factor V Leiden was not associated with the combined outcome of myocardial infarction and CHD death (hazard ratio, 1.03 [95% CI, 0.92-1.16]; I2=28%; P-heterogeneity=0.12). Subgroup analysis according to baseline characteristics or strata of traditional cardiovascular risk factors did not show relevant differences. Similarly, risk estimates for the secondary outcomes including stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality were also close to identity.

CONCLUSIONS

Factor V Leiden was not associated with increased risk of subsequent atherothrombotic events and mortality in high-risk participants with established and treated CHD. Routine assessment of factor V Leiden status is unlikely to improve atherothrombotic events risk stratification in this population.

Correlation Between PAI-1 Gene 4G/5G Polymorphism and the Risk of Thrombosis in Ph Chromosome-Negative Myeloproliferative Neoplasms

Thrombosis has been recognized as one of the most significant risk factors of high mortality and disability in patients with Philadelphia (Ph) chromosome negative myeloproliferative neoplasms (MPNs). However, the risk factors of thrombotic events in these patients have not been completely understood. In this study, the clinical data of 58 patients with Ph-MPNs were obtained and analyzed, including 34 cases of essential thrombocytopenia (ET), 23 thrombotic events happened in 21 (36%) patients, among which 60% (14 of 23) with cerebral infarction, 17% (4 of 23) with coronary heart disease and 23% (5 of 23) with venous thrombosis. There were no significant differences in age, sex, and blood cell count between polycythemia vera (PV) and ET patients who have experienced thrombotic events and those who have not. In ET patients, the incidence of thrombotic events in plasminogen activator inhibitor-1 (PAI-1) genotype 4G4G was significantly higher than that in genotype 4G5G and genotype 5G5G (P < .05). The incidence of thrombotic events in PV and ET patients with infection was higher than those without infection (P < .05). Using logistic regression analysis, we found that PAI-1 genotype 4G4G and infection were associated with thrombotic events (odds ratio 6.744, 95% CI: 1.195-38.056 and 15.641 95% CI: 3.327-73.522). The 4G/4G polymorphism of PAI-1 gene and infection are independent risk factors of thrombotic events in patients with Ph-MPNs. PAI-1 gene 4G4G and infection in ET and PV patients with Janus kinase 2 (JAK2) V617F mutation were shown to be high risk of thrombotic events. Therefore, clinical doctors should put more attention on PAI-1 genotype 4G4G and infection in JAK2 V617F mutated patients with Ph-MPNs to prevent the thrombosis.

"Noninfective Endocarditis": A Case Report of Hereditary Coagulation Disorders in a 28-Year-Old Male

We report a case of a young male who presented with acute limb ischemia after sport. With no prior history of disease, a non-infective endocarditis of the native aortic valve was diagnosed. After surgical valve replacement, the patient suffered from acute myocardial ischemia under phenprocoumon therapy. Anti-coagulant monitoring was subsequently changed to Factor II analysis after a rare Factor VII deficiency and prothrombin mutation (G20210A) was diagnosed.

Arterial and venous thrombosis: What's the link? A narrative review

Arterial thrombosis and venous thromboembolism (VTE) are traditionally considered two different entities. However, patients with unprovoked VTE are at higher risk of developing subclinical and overt atherosclerosis compared to healthy controls challenging these distinctions. Obesity may explain the association between arterial and venous disease: overweight/obese patients are prone to stasis in lower limbs veins, chronic inflammation, dyslipidemia, hypertension, and diabetes mellitus; all of which result in a hypercoagulability, VTE, and atherosclerosis. Novel therapeutic approaches combining and re-purposing traditional arterial therapies (antiplatelets and statins) and venous thrombosis therapies (anticoagulants) are emerging for the management of patients with vascular disease.

Myocardial infarction, prothrombotic genotypes, and venous thrombosis risk: The Tromsø Study

BACKGROUND

The risk of venous thromboembolism (VTE) is increased after a myocardial infarction (MI). Some prothrombotic genotypes associated with VTE have also been associated with risk of MI. Whether prothrombotic single-nucleotide polymorphisms (SNPs) further increase the risk of VTE in MI patients is scarcely investigated.

AIM

To study the combined effect of MI and prothrombotic SNPs on the risk of VTE.

METHODS

Cases with incident VTE (n = 641) and a randomly sampled subcohort weighted for age (n = 1761) were identified from the 4 to 6 surveys of the Tromsø Study (1994-2012). DNA was genotyped for rs8176719 (ABO), rs6025 (F5), rs1799963 (F2), rs2066865 (FGG), and rs2036914 (F11). Hazard ratios (HRs) for VTE with 95% confidence intervals (CIs) were estimated by categories of risk alleles and MI status.

RESULTS

Patients with MI had a 1.4-fold increased risk of VTE, and adjustments for the 5 SNPs, either alone or in combination, did not affect this relationship (adjusted HR, 1.52; 95% CI, 1.12-2.07). In subjects without MI, an increased risk of VTE was observed for each of the individual SNPs (≥1 vs. 0 risk alleles), and the risk increased linearly with increasing number of risk alleles in the 5-SNP score. The combination of MI and prothrombotic genotypes, either as individual SNPs or in the 5-SNP score, did not result in an excess risk of VTE.

CONCLUSION

The relationship between MI and VTE was not explained by these 5 prothrombotic genotypes. Prothrombotic genotypes did not yield an excess risk of VTE in patients with MI.

Clinically Significant Bleeding With Ticagrelor Versus Clopidogrel in Korean Patients With Acute Coronary Syndromes Intended for Invasive Management

Background:

Owing to the differential propensity for bleeding and ischemic events with response to antiplatelet therapy, the safety and effectiveness of potent P2Y12 inhibitor ticagrelor in East Asian populations remain uncertain.

Methods:

In this multicenter trial, 800 Korean patients hospitalized for acute coronary syndromes with or without ST elevation and intended for invasive management were randomly assigned to receive, in a 1:1 ratio, ticagrelor (180 mg loading dose, 90 mg twice daily thereafter) or clopidogrel (600 mg loading dose, 75 mg daily thereafter). The primary safety outcome was clinically significant bleeding (a composite of major bleeding or minor bleeding according to PLATO (Platelet Inhibition and Patient Outcomes) criteria at 12 months.

Results:

At 12 months, the incidence of clinically significant bleeding was significantly higher in the ticagrelor group than in the clopidogrel group (11.7% [45/400] vs 5.3% [21/400]; hazard ratio [HR], 2.26; 95% confidence interval [CI], 1.34 to 3.79; P =0.002). The incidences of major bleeding (7.5% [29/400] vs 4.1% [16/400], P =0.04) and fatal bleeding (1% [4/400] vs 0%, P =0.04) were also higher in the ticagrelor group. The incidence of death from cardiovascular causes, myocardial infarction, or stroke was not significantly different between the ticagrelor group and the clopidogrel group (9.2% [36/400] vs 5.8% [23/400]; HR, 1.62; 95% CI, 0.96 to 2.74; P =0.07). Overall safety and effectiveness findings were similar with the use of several different analytic methods and in multiple subgroups.

Conclusions:

In Korean acute coronary syndrome patients intended to receive early invasive management, standard-dose ticagrelor as compared with clopidogrel was associated with a higher incidence of clinically significant bleeding. The numerically higher incidence of ischemic events should be interpreted with caution, given the present trial was underpowered to draw any conclusion regarding efficacy.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov . Unique identifier: NCT02094963.

Impact of prothrombotic genotypes on the association between family history of myocardial infarction and venous thromboembolism

BACKGROUND

Family history of myocardial infarction (FHMI) is known to increase the risk of venous thromboembolism (VTE).

OBJECTIVES

To investigate the effect of prothrombotic genotypes on the association between FHMI and VTE in a case-cohort recruited from a general population.

METHODS

Cases with a first VTE (n = 1493) and a subcohort (n = 13 072) were sampled from the Tromsø study (1994-2012) and the Nord-Trøndelag health (HUNT) study (1995-2008). The DNA samples were genotyped for rs8176719 (ABO), rs6025 (F5), rs1799963 (F2), rs2066865 (FGG), and rs2036914 (F11). Participants with missing information on risk alleles (n = 175), FHMI (n = 2769), and BMI (n = 52) were excluded. Cox regression models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CI) for VTE. To explore the role of prothrombotic genotypes for the association between FHMI and VTE, we (a) included the genotypes in the multivariable-adjusted models and (b) assessed the joint effects between FHMI and genotypes on VTE risk.

RESULTS

The FHMI was associated with a 1.3-fold increased risk of VTE (HR 1.32, 95% CI 1.16-1.50) and 1.5-fold increased risk of unprovoked VTE (HR 1.47, 95% CI 1.22-1.78). The risk of VTE by FHMI did not alter after adjustment for the five genotypes. The combination of FHMI and the different prothrombotic genotypes did not result in an excess VTE risk (i.e. no biological interaction).

CONCLUSIONS

Our findings suggest that the risk of VTE by FHMI is not explained by rs8176719 (ABO), rs6025 (F5), rs1799963 (F2), rs2066865 (FGG), and rs2036914 (F11). The combination of FHMI with prothrombotic genotypes had an additive effect on VTE risk.

Integrin ß1 polymorphisms and bleeding risk after coronary artery stenting

Bleeding complications following percutaneous coronary intervention associate with increased mortality. However, the underlying molecular mechanisms are insufficiently understood. Platelet recruitment and activation at sites of vascular injury depends on the function of integrin adhesion receptors. Besides GPIIbIIIa as the most abundant integrin receptor, platelets relevantly express ß1 integrins. Experimental evidence from in vivo studies suggests a significant role of ß1 integrins in primary haemostasis. However, little is known about the clinical impact of genetic alterations of the β1 subunit, which might contribute to bleeding complications in patients. In this study, we performed DNA sequencing of patients suffering from bleeding complications after coronary artery stenting according to TIMI or BARC classification. We isolated DNA samples from 741 patients out of a cohort from 14,160 patients recruited in seven randomized clinical trials between June 2000 and May 2011. Subsequently, Sanger sequencing was performed covering the β1 integrin cytoplasmic activation domain (exon16) and its non-coding upstream region. Out of 764 patients suffering from bleeding complications, 741 DNA samples were successfully sequenced. Genotype variation was detected for SNP rs2153875 located within the non-coding upstream region with following allele frequency in study population: CC (7.3%), CA (35%) and AA (57.8%), which is similar to a general population cohort. Further, genotype variation in SNP rs2153875 do not associate with the frequency of TIMI or BARC classified access or non-access site bleedings. Genotype variations of the β1 integrin activation domain do not associate with bleeding risk after PCI.

From genome-wide association studies to Mendelian randomization: novel opportunities for understanding cardiovascular disease causality, pathogenesis, prevention, and treatment

The Mendelian randomization approach is an epidemiological study design incorporating genetic information into traditional epidemiological studies to infer causality of biomarkers, risk factors, or lifestyle factors on disease risk. Mendelian randomization studies often draw on novel information generated in genome-wide association studies on causal associations between genetic variants and a risk factor or lifestyle factor. Such information can then be used in a largely unconfounded study design free of reverse causation to understand if and how risk factors and lifestyle factors cause cardiovascular disease. If causation is demonstrated, an opportunity for prevention of disease is identified; importantly however, before prevention or treatment can be implemented, randomized intervention trials altering risk factor levels or improving deleterious lifestyle factors needs to document reductions in cardiovascular disease in a safe and side-effect sparse manner. Documentation of causality can also inform on potential drug targets, more likely to be successful than prior approaches often relying on animal or cell studies mainly. The present review summarizes the history and background of Mendelian randomization, the study design, assumptions for using the design, and the most common caveats, followed by a discussion on advantages and disadvantages of different types of Mendelian randomization studies using one or more samples and different levels of information on study participants. The review also provides an overview of results on many of the risk factors and lifestyle factors for cardiovascular disease examined to date using the Mendelian randomization study design.

Safety and Effectiveness of Contemporary P2Y12 Inhibitors in an East Asian Population With Acute Coronary Syndrome: A Nationwide Population-Based Cohort Study

Background

Prior reports indicate that the effect of P2Y₁₂ inhibitors may be different in East Asian patients (“East Asian paradox”); therefore, understanding the outcomes associated with potent P2Y₁₂ inhibitors in different populations is clinically important.

Methods and Results

In this observational cohort study using administrative healthcare data sets, we compared safety and effectiveness of contemporary P2Y₁₂ inhibitors in patients with acute coronary syndrome. The primary safety outcomes were major and any bleeding, and the primary effectiveness outcomes were major cardiovascular events (a composite of cardiovascular death, myocardial infarction, or stroke) and all‐cause mortality. Among 70 715 patients with acute coronary syndrome, 56 216 (79.5%) used clopidogrel, 11 402 (16.1%) used ticagrelor, and 3097 (4.4%) used prasugrel. The median follow‐up period was 18.0 months (interquartile range: 9.6–26.4 months). In a propensity‐matched cohort, compared with clopidogrel, ticagrelor was associated with a higher risk of any bleeding (hazard ratio: 1.23; 95% CI, 1.14–1.33) but a lower risk of mortality (hazard ratio: 0.76; 95% CI, 0.63–0.91). Prasugrel, compared with clopidogrel, was associated with higher risks of any bleeding (hazard ratio: 1.23; 95% CI, 1.06–1.43) and major bleeding (hazard ratio: 1.50; 95% CI, 1.01–2.21) but a similar risk of effectiveness outcomes. No significant difference was noted between ticagrelor and prasugrel with respect to key safety or effectiveness outcomes. Several sensitivity analyses showed similar results.

Conclusions

In East Asian patients with acute coronary syndrome, compared with clopidogrel, ticagrelor was associated with an increased risk of bleeding but a decreased risk of mortality. Prasugrel was associated with an increase of any bleeding without difference in effectiveness outcomes. The risks of bleeding and ischemic events were similar between ticagrelor and prasugrel.

Genetic and Nongenetic Implications of Racial Variation in Response to Antiplatelet Therapy

Race has been identified as an independent risk factor for poor prognosis and an independent predictor of survival in coronary artery disease. Race-related dissimilarities have been identified in cardiovascular patients in terms of age of presentation, co-morbidities, socioeconomic status, and treatment approach as well as genetically driven race-related disparities in responsiveness to medications. Antiplatelet therapy represents a fundamental component of therapy in cardiovascular patients, especially in patients presenting with acute coronary syndromes. It has been argued that the different level of platelet reactivity and varying response to antiplatelet therapy among races may account in part for worse outcomes in certain populations. The purpose of this review is to describe genotypic and phenotypic race-related differences in platelet reactivity and responsiveness to cardiovascular treatment, focusing on antiplatelet therapy to highlight the need establish a more effective and targeted antithrombotic strategy.

D-Dimer to Predict the Clinical Outcomes in Patients with Mechanical Heart Valve Replacement During Oral Anticoagulation Therapy

Mechanical heart valve replacement (MHVR) entails lifetime oral anticoagulation to eliminate thrombosis. However, adverse events may still occur despite proper anticoagulation therapy. In this study, we investigated whether D-dimer can predict the clinical events in post-MHVR patients during oral anticoagulation therapy.This was a single-center, prospective study. In all, 772 patients who underwent MHVR in the Wuhan Asia Heart Hospital from January 2013 to May 2014 were screened. Patients were assigned to the abnormal D-dimer group and the normal D-dimer group according to the D-dimer levels measured 3 months after the beginning of the oral anticoagulation therapy regime. All patients were followed up for 24 months or until the observation of the endpoints, which included thrombotic events, bleeding events, and all-cause deaths.A total of 718 patients were included in the analysis: 91 had abnormal D-dimer levels, and 627 had normal D-dimer levels. In all, 53 events were observed during 24 months. Compared with the normal D-dimer group, patients with abnormal D-dimer levels had a higher incidence of thrombotic events (10 versus 14; hazard ratio (HR): 5.36; 95% confidence interval (CI): 2.38-12.1; P < 0.001), all-cause mortality (8 versus 13; HR: 4.65; 95% CI: 1.93-11.2; P < 0.001), and a higher incidence of total events (16 versus 37; HR: 3.26; 95% CI: 1.81-5.86; P < 0.001). No significant difference was observed in bleeding events (2 versus 21; HR: 0.72; 95% CI: 0.17-3.07; P = 0.66).D-dimer may be a useful marker to predict thrombotic events and all-cause deaths in post-MHVR patients during oral anticoagulation therapy (ClinicalTrials.gov; NCT01996657).

High prevalence of inherited thrombophilia and antiphospholipid syndrome in myocardial infarction with non-obstructive coronary arteries: Comparison with cryptogenic stroke

BACKGROUND

A role of thrombophilia in myocardial infarction with non-obstructive coronary arteries (MINOCA) is unclear. We investigated thrombophilic factors in MINOCA patients versus those following cryptogenic stroke (CS), a well-established indication for thrombophilia screening.

METHODS

In a prospective cross-sectional study, we assessed 84 consecutive patients (median age: 45.5 years) at least 3 months after MINOCA. Age-matched CS patients (n = 84) and published data on general population served as controls. Thrombophilia screening involved inherited thrombophilia (factor V Leiden, prothrombin G20210A mutation, deficiency of protein C, protein S or antithrombin), antiphospholipid syndrome (APS), along with factor VIII >150%, homocysteine ≥15 μM and lipoprotein (a) >30 mg/dl.

RESULTS

Compared to CS, MINOCA were more often males (60.7 vs 33.3%, P < 0.001), obese (34.5 vs 17.9%, P = 0.014), smokers (51.2 vs 35.7%, P = 0.043) and had family history of myocardial infarction (27.4 vs 6.0%, P < 0.001). Inherited thrombophilia occurred in 20 (23.8%) MINOCA patients and in 13 (15.5%) with CS (P = 0.17), without any difference in the parameters except for elevated lipoprotein (a) that was less common in MINOCA (21.4 vs 39.3%, P = 0.012). APS was found in 13 (15.5%) of MINOCA patients, mostly in a single-positive form. APS was diagnosed less frequently in STEMI (2.5 vs 27.3% for NSTEMI, P = 0.002) and MINOCA patients aged ≤50 years (5.7 vs 32.3% for older subjects, P = 0.003).

CONCLUSIONS

MINOCA patients exhibit high prevalence of thrombophilia including APS, similar to that in CS. Our first comprehensive thrombophilia testing in MINOCA supports its clinical relevance and the need for long-term anticoagulation for some abnormalities, especially APS.

Cryptogenic stroke - How to make sense of a non-diagnostic entity

Secondary preventive strategies in ischaemic stroke depend on the underlying aetiology. However, approximately one-third of ischaemic strokes remain unexplained, or 'cryptogenic'. There is a wide range of possible underlying causes in cryptogenic stroke, and the best approach to secondary prevention of these may differ. To date, though, the widely accepted and uniform secondary preventive strategy in this group consists of modification of vascular risk factors, and of treatment with a combination of antiplatelet therapy and antihypertensive and lipid-lowering medication. Among the potential causes for cryptogenic stroke are occult atrial fibrillation, patent foramen ovale, atrial cardiopathy, aortic arch atheroma and hypercoagulable states. While it is possible to diagnose these conditions, in individual patients there is often uncertainty over whether they have a directly causative role, are markers of disease, or are innocent bystanders. Similarly, even if the cause is found, the best secondary preventive strategies remain uncertain, which questions the benefit of extensive investigations in a clinical setting. More recently, the concept of "embolic stroke of unknown source (ESUS)" has been introduced, in the hope that anticoagulation may offer better secondary prevention than antiplatelet therapy, but trials so far have been negative. At present, there is little justification for introducing extensive new investigative strategies into the management of patients with cryptogenic stroke. Investigations should be targeted at identifying those high-risk conditions which lead to a change in management. Further investigations need to be tailored individually, according to clinical circumstances. This should include identifying patients for participation in clinical trials, as the significance and best management of many of the potential causes for cryptogenic stroke require further research.

DAPT Plus Cilostazol is Better Than Traditional DAPT or Aspirin Plus Ticagrelor as Elective PCI for Intermediate-to-Highly Complex Cases: Prospective, Randomized, PRU-Based Study in Taiwan

PURPOSE

Current treatment guidelines do not recommend different antiplatelet treatments for patients in different coronary risk categories; nor do they consider ethnic differences in responses to individual drugs.

OBJECTIVES

We performed a prospective, single-blind, randomized, comparative study of Taiwanese patients with stable angina and scheduled stent implantation for intermediate-to-highly complex coronary lesions and compared the platelet reactivity unit (PRU) levels and 24-month outcomes of groups receiving three different antiplatelet treatments.

METHODS

Patients (N = 334) were randomized into three treatment groups (aspirin + clopidogrel, aspirin + ticagrelor, or aspirin + clopidogrel + cilostazol) for 6 months of treatment and were then switched to aspirin only. PRU levels were determined 24 h, 7 days, and 1 month after stent implantation. Clinical outcomes and adverse events were recorded over 24 months.

RESULTS

Clopidogrel treatment reached full effect after 1 month. Ticagrelor decreased PRU levels more than did clopidogrel but often to levels that increased the risk of hemorrhage. The addition of cilostazol to clopidogrel decreased PRU levels earlier and more strongly than clopidogrel alone but not as strongly as did ticagrelor. Ticagrelor treatment caused fewer major adverse cardiovascular events (MACEs) and more episodes of minor bleeding than the other two treatments.

CONCLUSIONS

Clopidogrel appears safer than ticagrelor in Taiwanese patients with stable angina after stent implantation for intermediate-to-highly complex coronary lesions. The addition of cilostazol to clopidogrel may provide a more rapid decrease in PRU to therapeutic levels without increasing the risk of hemorrhage.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02101411.

Clinical Exome Sequencing unravels new disease-causing mutations in the myeloproliferative neoplasms: A pilot study in patients from the state of Qatar

Clinical Exome Sequencing (CES) has increasingly become a popular diagnostic tool in patients suffering from genetic disorders that are clinically and genetically complicated. Myeloproliferative Neoplasms (MPNs) is an example of a heterogeneous disorder. In Qatar, familial cases of MPNs are more frequently seen than described in the literature. In this study, we aimed to use CES to classify six Qatari subjects that were suspected of clinical diagnosis of MPNs, according to the WHO 2008 diagnostic criteria for hematologic malignancies, and identify variants that can potentially explain the phenotypic diversity of MPNs. We sequenced six Qatari subjects using CES, of whom, three probands were unrelated families and three members were from the same family, all probands come from consanguineous families, and had a positive family history of MPNs. CES identified 61 variants in 50 genes; of which, 13 were recurrently mutated in our patients. Ten novel variants were identified in ten known genes related to MPNs and seven variants were identified in seven novel candidate genes. The genotype of the six subjects was due to a combination of different variants in different genes. This study serves as a pilot study to investigate the complexity of the genotype of patients with MPNS in Qatar, and serves as a guide for further well-controlled genetic epidemiological studies for patients with MPNs. CES is a powerful tool to be used in the genetic clinics for differential and definitive diagnosis of patients with MPNs.

Polymorphism of R353Q (rs6046) in factor VII and the risk of myocardial infarction: A systematic review and meta-analysis

OBJECTIVE

Genetic components substantially contribute to the development of myocardial infarction (MI), and R353Q polymorphism (rs6046) in FVII gene has been suspected to be associated with the risk of MI.

METHODS

A meta-analysis was conducted on the links between R353Q polymorphism and the susceptibility of MI. A comprehensive literature search was performed on 8 electronic databases. The main effects of the genotypes were estimated using a logistic regression approach. The odds ratios with 95% confidence intervals were calculated using the conventional summary method meta-analysis. The possible sources of heterogeneity among the included studies were explored using meta-regression analysis and subgroup analysis.

RESULTS

A total of 18 eligible case-control studies, comprising of 4701 cases and 5329 controls, were included. No overall statistical relationship was identified between R353Q and MI by any of the genetic models. The meta-regression demonstrated that the Asian population, body mass index (BMI) category, and diabetes affected the heterogeneity. In addition, subgroup analyses showed that heterogeneities were identified in Asian population and BMI category, which highly agree with the results of meta-regression.

CONCLUSIONS

The current meta-analysis suggested that R353Q polymorphism was not associated with the MI risk. Asian population, BMI category, and diabetes might be related to the incidence of MI. However, large-scale, case-control studies with rigorous designs are essential to provide accurate evidence.

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.