Factoring in Factor VIII With Acute Ischemic Stroke

Blood group and ischemic stroke, myocardial infarction, and peripheral vascular disease: A meta-analysis of over 145,000 cases and 2,000,000 controls

OBJECTIVE

Cardiovascular illnesses have been associated to ABO blood types, specifically through an effect on von Willebrand factor and factor FVIII levels. We conducted a meta-analysis to comprehensively explore the relationship between blood groups and ischemic stroke, myocardial infarction, and peripheral vascular disease.

MATERIALS AND METHODS

A comprehensive meta-analysis was undertaken to investigate blood groups and ischemic stroke (IS), myocardial infarction (MI) and peripheral vascular disease (PVD). Odds ratios (OR) were used to assess the relationship between blood groups and disease. RevMan v5,4 was used to statistically analyse the results. Risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

A total of 72 studies (18 ischemic stroke, 37 myocardial infarction, 17 peripheral vascular disease) met our search criteria, totalling 145,499 cases and 2,113,736 controls. Mean age ranged between 18 and 90 years. Compared to blood group-O, non-O blood group had an increased association with IS (OR=1.13, 95%Cl: 1.07-1.21, P < 0.001), MI (OR=1.17, 95%Cl: 1.11-1.24, P < 0.001) and PVD (OR=1.15, 95%Cl: 1.04-1.28, P=0.005). Compared to blood group-O, blood group A had a stronger statistically significant association to IS (OR=1.19, P=0.001), MI (OR=1.22, P < 0.001) and PVD (OR=1.15, P=0.03). Blood group-B has the lowest risk associated with MI (OR=1.09, P=0.01). In addition, blood groups AB had a stronger statistically significant association to IS (OR=1.24, P=0.01), and MI (OR=1.20, P < 0.001) compared with the other blood groups.

CONCLUSIONS

Compared to blood group-O, groups A and AB are strongly associated to ischemic stroke, myocardial infarction, and peripheral vascular disease.

Coagulation biomarkers for ischemic stroke

A State of the Art lecture titled "coagulation biomarkers for ischemic stroke" was presented at the International Society on Thrombosis and Haemostasis (ISTH) Congress in 2022. Ischemic stroke (IS) is a common disease with major morbidity and mortality. It is a challenge to determine which patients are at risk for IS or have poor clinical outcome after IS. An imbalance of coagulation markers may contribute to the progression and prognosis of IS. Therefore, we now discuss studies on the association of selected coagulation biomarkers from the hemostasis, inflammation, and immunothrombosis systems with the risk of IS, stroke severity at the acute phase, and clinical outcome after treatment. We report on coagulation biomarker-induced risk of IS, stroke severity, and outcomes following IS derived from prospective population studies, case-control studies, and acute-phase IS studies. We found indications that many coagulation and inflammation biomarkers are associated with IS, but it is early to conclude that any of these biomarkers can be applied in a therapeutic setting to predict patients at risk of IS, stroke severity at the acute phase, and clinical outcome after treatment. The strongest evidence for a role in IS was found for beta-thromboglobulin, von Willebrand factor, factor VIII, fibrinogen, thrombin-activatable fibrinolysis inhibitor, D-dimer, and neutrophil extracellular traps, and therefore, they are promising candidates. Further research and validation in large-size populations using well-defined study designs are warranted. Finally, we provide a selection of recent data relevant to this subject that was presented at the 2022 ISTH Congress.

Effect of PCSK9 Inhibitors on Hemostasis in Patients with Isolated Hypercholesterolemia

Background: In addition to reducing plasma lipids, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors may produce numerous nonlipid-related pleiotropic effects. The purpose of this trial was to determine the efficacy of PCSK9 inhibitors alone in patients with isolated hypercholesterolemia. Methods: The trial enrolled 21 individuals with isolated hypercholesterolemia and atherosclerosis who received alirocumab for 90 days (150 mg every two weeks). Lipids, glucose homeostasis factors, and hemostatic markers were measured in the plasma at baseline and after treatment. Results: The PCSK9 inhibitor administered to these patients reduced plasma levels/activity of fibrinogen (from 3.6 ± 0.5 to 2.9 ± 0.4 g/L, p < 0.01), factor VII (from 143.8 ± 16.7 to 114.5 ± 14.1%, p < 0.01) and plasminogen activator inhibitor-1 (PAI-1) (from 74.9 ± 13.9 to 52.8 ± 9.1 ng/mL, p < 0.001) without a significant reduction in von Willebrand factor levels, and it tended to prolong the partial thromboplastin and prothrombin times. Conclusion: Our findings indicate that treatment with PCSK9 inhibitors has a multipotential effect on fibrinolysis and coagulation in patients with isolated hypercholesterolemia and that this medication may have some future benefits in patients who are statin-intolerant or contraindicated to statin use.

Insight into the Evolving Role of PCSK9

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is the last discovered member of the family of proprotein convertases (PCs), mainly synthetized in hepatic cells. This serine protease plays a pivotal role in the reduction of the number of low-density lipoprotein receptors (LDLRs) on the surface of hepatocytes, which leads to an increase in the level of cholesterol in the blood. This mechanism and the fact that gain of function (GOF) mutations in PCSK9 are responsible for causing familial hypercholesterolemia whereas loss-of-function (LOF) mutations are associated with hypocholesterolemia, prompted the invention of drugs that block PCSK9 action. The high efficiency of PCSK9 inhibitors (e.g., alirocumab, evolocumab) in decreasing cardiovascular risk, pleiotropic effects of other lipid-lowering drugs (e.g., statins) and the multifunctional character of other proprotein convertases, were the cause for proceeding studies on functions of PCSK9 beyond cholesterol metabolism. In this article, we summarize the current knowledge on the roles that PCSK9 plays in different tissues and perspectives for its clinical use.

Rare case of simultaneous cerebral artery and venous sinus thrombosis in the setting of elevated factor VIII and combined oral contraceptive pills

We report a rare case of combined cerebral venous sinus thrombosis and ischemic stroke in a 35‐year‐old female on combined oral contraceptive pills (COCPs) with persistently elevated factor VIII, presenting with headache and sudden onset vertigo, found to have extensive cerebral venous sinus thrombosis and PICA territory ischemic infarct.

Osteonecrosis of the Jaws in Patients with Hereditary Thrombophilia/Hypofibrinolysis-From Pathophysiology to Therapeutic Implications

Osteonecrosis of the jaws (ONJ) usually has a clear etiology. Local infection or trauma, radiotherapy and drugs that disrupt the vascular supply or bone turnover in the jaws are its major contributors. The thrombotic occlusion of the bone’s venous outflow that occurs in individuals with hereditary thrombophilia and/or hypofibrinolysis has a less known impact on jaw health and healing capability. Our research provides the most comprehensive, up-to-date and systematized information on the prevalence and significance of hereditary thrombophilia and/or hypofibrinolysis states in ONJ. We found that hereditary prothrombotic abnormalities are common in patients with ONJ refractory to conventional medical and dental treatments. Thrombophilia traits usually coexist with hypofibrinolysis traits. We also found that frequently acquired prothrombotic abnormalities coexist with hereditary ones and enhance their negative effect on the bone. Therefore, we recommend a personalized therapeutic approach that addresses, in particular, the modifiable risk factors of ONJ. Patients will have clear benefits, as they will be relieved of persistent pain and repeated dental procedures.

Efficacy and Safety of PCSK9 Inhibitors in Stroke Prevention

Proprotein convertase subtilisin/kexin type 9 (PCSK9) interacts with the low-density lipoprotein (LDL) receptor and, by enhancing its degradation, has a pivotal role in the regulation of cholesterol homeostasis. Two fully humanized monoclonal antibodies targeting PCSK9, evolocumab and alirocumab, are available for clinical use. PCSK9 inhibitors reduce LDL-C 30% more than ezetimibe and 60% more than placebo when added to statins. This reduction in LDL-C is accompanied by a decrease in the risk of major cardiovascular and cerebrovascular events. However, questions have been raised in relation to the cost-effectiveness of these medications. In this article, we review the clinical evidence on the use of PCSK9 inhibitors in lowering LDL-C and their effect on cerebrovascular health.

A review on clotting disorders and retinal hemorrhages: Can they mimic abuse?

BACKGROUND

The characteristic findings of abusive head trauma (AHT) include retinal hemorrhages (RH). RH have many etiologies in childhood, which should be considered in the differential diagnosis of possible child abuse. The relationship between RH and thrombophilia in children is not well established.

OBJECTIVE

In this literature review, we sought to assess whether retinal findings in pediatric patients with thrombophilia could mimic those of AHT.

METHODS

A literature search was performed to identify all cases of thrombophilia in children less than 18 years old with ocular manifestations. Disorders of thrombophilia including protein C and S deficiency, factor V Leiden (FVL), prothrombin variant, MTHFR mutation, hyperhomocysteinemia, elevated factor VIII, and elevated lipoprotein (a) were considered. All cases of pediatric thrombophilia with retinal examination or intraocular bleeding were included. If provided, descriptions of the RH were reviewed.

RESULTS

Our initial search yielded 514 results. Forty-three articles met our inclusion criteria. We identified 3 children with RH within the AHT usual age range (<5 years old), ages 5 weeks and 7 weeks old, in the setting of thrombophilia. One child had ocular findings that could potentially mimic abuse. No other indicators of abuse were present in this case.

CONCLUSIONS

Based on previous reports, thrombophilia alone has not been shown to clearly mimic abusive head trauma. In reported cases of thrombophilia with RH, the clinical picture and ophthalmic findings are usually distinct from abuse.

Pleiotropic Effects of PCSK-9 Inhibitors

Proprotein convertase subtilisin/kexin type 9 (PCSK-9) inhibitors are a group of drugs whose main mechanism of action is binding to the PCSK-9 molecule, which reduces the degradation of the low-density lipoprotein receptor (LDL-R) and, hence, increases the uptake of low-density lipoprotein cholesterol (LDLc) from the bloodstream as well as reducing its concentration. The effectiveness of three monoclonal antibodies, namely, alirocumab (human IgG1/κ monoclonal antibody, genetically engineered in Chinese hamster ovary cells), evolocumab (the first fully human monoclonal antibody), and bococizumab (humanized mouse antibody), in inhibiting the action of PCSK-9 and reducing LDLc levels has been confirmed. The first two, after clinical trials, were approved by the Food and Drug Administration (FDA) and are used primarily in the treatment of autosomal familial hypercholesterolemia and in cases of statin intolerance. They are currently used both as monotherapy and in combination with statins and ezetimibe to intensify therapy and achieve therapeutic goals following the American Heart Association (AHA) and European Society of Cardiology (ESC) guidelines. However, the lipid-lowering effect is not the only effect of action described by researchers that PCSK-9 inhibitors have. This paper is a review of the literature describing the pleiotropic effects of PCSK-9 inhibitors, which belong to a group of drugs that are being increasingly used, especially when standard lipid-lowering therapy fails. The article focuses on activities other than lipid-lowering, such as the anti-atherosclerotic effect and stabilization of atherosclerotic plaque, the anti-aggregation effect, the anticoagulant effect, the antineoplastic effect, and the ability to influence the course of bacterial infections. In this publication, we try to systematically review the current scientific data, both from our own scientific work and knowledge from international publications.

Elevated factor VIII levels and arterial stroke: a review of literature with a case report

Background

Cerebral arterial thromboses or ischemic strokes may be caused by cumulative or independent effects of a variety of risk factors. High factor VIII level is one of those important but less known risk factors for arterial and venous thrombosis. We hereby provide a comprehensive review of the role of high factor VIII levels as a risk factor of arterial thrombosis. Moreover, we present our views on inclusion of factor VIII testing in the etiology workup protocol of young patients with ischemic strokes and their treatment with anticoagulant therapy.

Case presentation

We illustrate a case of 32-year-old North Indian female patient with Ischemic stroke whose only identifiable risk factor was revealed to be an elevated factor VIII level. She was treated with oral anticoagulant with an uneventful follow-up of 6 months.

Conclusions

Elevated factor VIII levels have their independent and additive effects in causation and prognosis of arterial strokes. We herein discuss the mechanism of this association, the feasibility and yield of routine testing, appropriate cut-off levels, and further treatment protocol especially in young stroke patients.

Coagulation factor XII, XI, and VIII activity levels and secondary events after first ischemic stroke

BACKGROUND

Though risk for recurrent vascular events is high following ischemic stroke, little knowledge about risk factors for secondary events post-stroke exists.

OBJECTIVES

Coagulation factors XII, XI, and VIII (FXII, FXI, and FVIII) have been implicated in first thrombotic events, and our aim was to estimate their effects on vascular outcomes within 3 years after first stroke.

PATIENTS/METHODS

In the Prospective Cohort with Incident Stroke Berlin (PROSCIS-B) study, we followed participants aged 18 and older for 3 years after first mild to moderate ischemic stroke event or until occurrence of recurrent stroke, myocardial infarction, or all-cause mortality. We compared high coagulation factor activity levels to normal and low levels and also analyzed activities as continuous variables. We used Cox proportional hazards models adjusted for age, sex, and cardiovascular risk factors to estimate hazard ratios (HRs) for the combined endpoint.

RESULTS

In total, 94 events occurred in 576 included participants, resulting in an absolute rate of 6.6 events per 100 person-years. After confounding adjustment, high FVIII activity showed the strongest relationship with the combined endpoint (HR = 2.05, 95% confidence interval [CI] 1.28-3.29). High FXI activity was also associated with a higher hazard (HR = 1.80, 95% CI 1.09-2.98), though high FXII activity was not (HR = 0.86, 95% CI 0.49-1.51). Continuous analyses yielded similar results.

CONCLUSIONS

In our study of mild to moderate ischemic stroke patients, high activity levels of FXI and FVIII but not FXII were associated with worse vascular outcomes in the 3-year period after first ischemic stroke.

Activated factor VIII-mimicking effect by emicizumab on thrombus formation in type 2N von Willebrand disease under high shear flow conditions

INTRODUCTION

Type 2N von Willebrand disease (2NVWD) is characterized by a mild to moderate reduction in plasma levels of factor (F)VIII associated with defective binding of von Willebrand factor (VWF) to FVIII and accelerated proteolysis and clearance of FVIII. The clinical phenotype in 2NVWD is often indistinguishable from mild/moderate hemophilia (H)A. Emicizumab is a bispecific antibody to FIX/FIXa and FX/FXa that mimics FVIIIa cofactor function, and emicizumab prophylaxis significantly reduces bleeding events in patients with severe HA.

AIM

We investigated the potential benefits of emicizumab in the hemostatic management of 2NVWD.

PATIENTS/METHODS

Perfusion chamber experiments were performed using whole blood from three 2NVWD patients with different clinical phenotypes (bleeding scores: 0, 6 and 20; mutations: p.R816W, p.R816W, and p.R365X/p.T791M, respectively). Furthermore, the impact of specific FVIII-VWF interactions on thrombus formation was investigated.

RESULTS

Defective thrombus formation that correlated with bleeding phenotype was evident in these 2NVWD patients. Emicizumab improved surface coverage and thrombus height in all cases. Multi-color immunostaining of thrombi further demonstrated that emicizumab enhanced thrombin generation and fibrin formation. The addition of FVIII alone to 2NVWD whole blood did not augment thrombus formation, while supplementation with FVIII/VWF complex enhanced platelet-fibrin interactions. Furthermore, an anti-FVIII monoclonal antibody known to interrupt the release of FVIIIa from VWF depressed these effects.

CONCLUSIONS

Emicizumab-induced enhancing effects of thrombus formation, independent on VWF, might be useful as an alternative therapy for 2NVWD patients. The extent of FVIII-VWF interaction should be optimal to deliver and release FVIII/FVIIIa on the activated platelet surface.

Coagulation factor VIII, white matter hyperintensities and cognitive function: Results from the Cardiovascular Health Study

OBJECTIVE

To investigate the relationship between high FVIII clotting activity (FVIII:C), MRI-defined white matter hyperintensities (WMH) and cognitive function over time.

METHODS

Data from the population-based Cardiovascular Health Study (n = 5,888, aged ≥65) were used. FVIII:C was measured in blood samples taken at baseline. WMH burden was assessed on two cranial MRI scans taken roughly 5 years apart. Cognitive function was assessed annually using the Modified Mini-Mental State Examination (3MSE) and Digit Symbol Substitution Test (DSST). We used ordinal logistic regression models adjusted for demographic and cardiovascular factors in cross-sectional and longitudinal WMH analyses, and adjusted linear regression and linear mixed models in the analyses of cognitive function.

RESULTS

After adjustment for confounding, higher levels of FVIII:C were not strongly associated with the burden of WMH on the initial MRI scan (OR>p75 = 1.20, 95% CI 0.99-1.45; N = 2,735) nor with WMH burden worsening over time (OR>p75 = 1.18, 95% CI 0.87-1.59; N = 1,527). High FVIII:C showed no strong association with cognitive scores cross-sectionally (3MSE>p75 β = -0.06, 95%CI -0.45 to 0.32, N = 4,005; DSST>p75 β = -0.69, 95%CI -1.52 to 0.13, N = 3,954) or over time (3MSE>p75 β = -0.07,95% CI -0.58 to 0.44, N = 2,764; DSST>p75 β = -0.22, 95% CI -0.97 to 0.53, N = 2,306) after confounding adjustment.

INTERPRETATION

The results from this cohort study of older adult participants indicate no strong relationships between higher FVIII:C levels and WMH burden or cognitive function in cross-sectional and longitudinal analyses.

Paroxysmal atrial fibrillation: changes in factor VIII and von Willebrand factor impose early hypercoagulability

Introduction

Paroxysmal atrial fibrillation (PAF) is a well-documented prothrombotic state that carries significant embolic risk. However, precise hemostatic changes in the very early stage of the disease are not completely studied. The aim of the study was to study von Willebrand factor (vWF) and coagulation factor VIII (FVIII) plasma levels and activity in the first hours (up to 24 h) of PAF clinical manifestation.

Material and methods

We selected consecutively 51 non-anticoagulated patients (26 men, 25 women, mean age: 59.84 ±1.60) with PAF and 52 controls (26 men, 26 women, mean age: 59.50 ±1.46 years) corresponding in gender, accompanying diseases and conducted treatment. The indicators were examined using enzyme-linked immunoassays and photometric tests.

Results

All patients were hospitalized between the 2^nd and 24^th h after the onset of arrhythmia (mean: 8.14 ±0.74 h). Higher FVIII levels (107.52 ±3.48% vs. 93.85 ±2.93%, p < 0.05) and activity (200.03 ±11.11% vs. 109.73 ±4.90%, p < 0.001) were found in the PAF group. vWF levels (178.40 ±12.95% vs. 119.53 ±6.12%, p < 0.001) and activity (200.92 ±12.45% vs. 110.80 ±5.14%, p < 0.001) were also higher. These changes did not depend on age, sex, body mass index or CHA₂DS₂-VASc score in the PAF group (p > 0.05). PAF duration was a significant predictor of increased FVIII levels and activity. Increased PAF duration was followed by increased values of the factors (r = 0.85, p < 0.001; r = 0.83, p < 0.001).

Conclusions

The results presented an activated coagulation cascade and endothelial injury, suggesting hypercoagulability still in the early hours of PAF. These changes in PAF did not correlate with CHA₂DS₂-VASc score risk factors, outlining PAF as a possible independent embolic risk factor.

Elevated Factor VIII and von Willebrand Factor Levels Predict Unfavorable Outcome in Stroke Patients Treated with Intravenous Thrombolysis

Introduction

Plasma factor VIII (FVIII) and von Willebrand factor (VWF) levels have been associated with the rate and severity of arterial thrombus formation and have been linked to outcomes following thrombolytic therapy in acute myocardial infarction patients. Here, we aimed to investigate FVIII and VWF levels during the course of thrombolysis in acute ischemic stroke (AIS) patients and to find out whether they predict long-term outcomes.

Materials and methods

Study population included 131 consecutive AIS patients (median age: 69 years, 60.3% men) who underwent i.v. thrombolysis with recombinant tissue plasminogen activator (rt-PA). Blood samples were taken on admission, 1 and 24 h after rt-PA administration to measure FVIII activity and VWF antigen levels. Neurological deficit of patients was determined according to the National Institutes of Health Stroke Scale (NIHSS). ASPECT scores were assessed using computer tomography images taken before and 24 h after thrombolysis. Intracranial hemorrhage was classified according to the European Cooperative Acute Stroke Study (ECASS) II criteria. Long-term functional outcome was determined at 90 days after the event by the modified Rankin scale (mRS).

Results

VWF levels on admission were significantly elevated in case of more severe AIS [median and IQR values: NIHSS <6:189.6% (151.9-233.2%); NIHSS 6-16: 199.6% (176.4-250.8%); NIHSS >16: 247.8% (199.9-353.8%), p = 0.013]; similar, but non-significant trend was observed for FVIII levels. FVIII and VWF levels correlated well on admission (r = 0.748, p < 0.001) but no significant correlation was found immediately after thrombolysis (r = 0.093, p = 0.299), most probably due to plasmin-mediated FVIII degradation. VWF levels at all investigated occasions and FVIII activity before and 24 h after thrombolysis were associated with worse 24 h post-lysis ASPECT scores. In a binary backward logistic regression analysis including age, gender, high-sensitivity C-reactive protein, active smoking, diabetes, and NIHSS >5 on admission, elevated FVIII and VWF levels after thrombolysis were independently associated with poor functional outcomes (mRS ≥ 3) at 90 days (immediately after thrombolysis: FVIII: OR: 7.10, 95% CI: 1.77-28.38, p = 0.006, VWF: OR: 6.31, 95% CI: 1.83-21.73, p = 0.003; 24 h after thrombolysis: FVIII: OR: 4.67, 95% CI: 1.42-15.38, p = 0.011, VWF: OR: 19.02, 95% CI: 1.94-186.99, p = 0.012).

Conclusion

Elevated FVIII activity and VWF antigen levels immediately after lysis and at 24 h post-therapy were shown to have independent prognostic values regarding poor functional outcomes at 90 days.

Sex differences in predictors of ischemic stroke: current perspectives

Globally, stroke is a significant public health concern affecting more than 33 million individuals. Of growing importance are the differences between males and females in the predictors and overall risk of stroke. Given that women have a higher lifetime risk for stoke and account for more than half of all stroke deaths, sex-specific stroke risk factors merit investigation and may help target public health interventions. This review aims to discuss the current body of knowledge regarding sex-specific predictors of ischemic stroke including both modifiable and non-modifiable risk factors, as well as specific pathologies known to increase stroke risk.