The hemostatic system as a modulator of atherosclerosis

Increased Neutrophil-lymphocyte and Platelet-lymphocyte Ratios in Male Heroin Addicts: A Prospective Controlled Study

Objective

The neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are markers that can determine the presence of systemic inflammatory response. In this study, we examined the NLR and PLR levels in patients with heroin dependence compared to healthy controls.

Methods

The study sample included 90 male patients with heroin dependence aged 18 to 45 years and 60 healthy subjects who had similar socio-demographic characteristics as the patient group. The diagnoses of heroin dependence and other Axis I psychiatric disorders in the patient and control groups were screened with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (SCID-I). The extent of heroin addiction was assessed with the Addiction Severity Index (ASI).

Results

The mean NLR and PLR levels of patients with heroin dependence were significantly higher than the control subjects (p=0.031 and p<0.001, respectively). Positive correlations were found between NLR, PLR and duration of the disorder.

Conclusion

Our results indicate that inflammatory processes may play a role in the pathophysiology of heroin dependence.

Protease-activated receptor 1 inhibits cholesterol efflux and promotes atherogenesis via cullin 3-mediated degradation of the ABCA1 transporter

Although signaling of thrombin via its receptor protease-activated receptor 1 (Par1) is known to occur in atherothrombosis, its link to the actual pathogenesis of this condition is less clear. To better understand the role of thrombin-Par1 signaling in atherosclerosis, here we have studied their effects on cellular cholesterol efflux in mice. We found that by activating Par1 and cullin 3-mediated ubiquitination and degradation of ABC subfamily A member 1 (ABCA1), thrombin inhibits cholesterol efflux in both murine macrophages and smooth muscle cells. Moreover, disruption of the Par1 gene rescued ABCA1 from Western diet-induced ubiquitination and degradation and restored cholesterol efflux in apolipoprotein E-deficient (ApoE^-/-) mice. Similarly, the Par1 deletion diminished diet-induced atherosclerotic lesions in the ApoE^-/- mice. These observations for the first time indicate a role for thrombin-Par1 signaling in the pathogenesis of diet-induced atherosclerosis. We identify cullin 3 as a cullin-RING ubiquitin E3 ligase that mediates ABCA1 ubiquitination and degradation and thereby inhibits cholesterol efflux. Furthermore, compared with peripheral blood mononuclear cells (PBMCs) from ApoE^-/- mice, the PBMCs from ApoE^-/-:Par1^-/- mice exhibited decreased trafficking to inflamed arteries of Western diet-fed ApoE^-/- mice. This finding suggested that besides inhibiting cholesterol efflux, thrombin-Par1 signaling also plays a role in the recruitment of leukocytes during diet-induced atherogenesis. Based on these findings, we conclude that thrombin-Par1 signaling appears to contribute to the pathogenesis of atherosclerosis by impairing cholesterol efflux from cells and by recruiting leukocytes to arteries.

Antiplatelet and anticoagulant for prevention of reocclusion in patients with atrial fibrillation undergoing endovascular treatment for low extremity ischemia

Background

The purpose of this study is to report the efficacy of the mono antiplatelet plus anticoagulation therapy for prevention of reocclusion in patients with atrial fibrillation (AF) undergoing endovascular treatment for lower extremity ischemia.

Methods

From March 2014 to July 2016, 32 (21 males; range, 68-84 years) patients were submitted to endovascular therapy for low extremity ischemia with AF and all were treated with endovascular treatments to correct underlying lesions. Then 20 patients receive aspirin plus rivaroxaban post-operation and 12 patients receive aspirin plus warfarin to prevent reocclusion.

Results

Complete reconstruction of occluded femopopliteal arteries with unimpeded blood flow to legs were successfully obtained in all 32 patients; 12 (37.5%) patients had acute ischemia, 17 (53.1%) patients had chronic ischemia, 3 (9.4%) patients had acute on chronic ischemia. Endovascular treatments including percutaneous transluminal angioplasty (PTA) and stenting were performed to correct residual lesions after the thrombolytic/thrombectomy procedure or to correct native lesions for chronic patients. All 32 patients showed significant improvements in symptoms and 4 patients improved completely. The mean ankle-brachial index (ABI) had risen from 0.43±0.21 preoperatively to 0.81±0.16 postoperatively (P<0.01), and the primary patency rates were 88.9% at 12 months, and 81.5% at 24 months. No episodes of major bleeding and only one patient showed positive fecal occult blood tests during the follow-up.

Conclusions

The mono antiplatelet plus anticoagulation therapy offers a safe and effective alternative for prevention of reocclusion in patients with AF undergoing endovascular treatment for lower extremity ischemic.

A direct oral factor Xa inhibitor edoxaban ameliorates neointimal hyperplasia following vascular injury and thrombosis in apolipoprotein E-deficient mice

Vascular injury activates the coagulation cascade. Some studies report that coagulation factor Xa and thrombin are implicated in proliferation of vascular smooth muscle cells and neointimal hyperplasia after vascular injury. The aim of this study was to determine the effect of an oral direct factor Xa inhibitor, edoxaban, on neointimal hyperplasia following the carotid artery injury in apolipoprotein E (ApoE)-deficient mice. Vascular injury was induced by the application of 10% ferric chloride to the carotid artery for 3 min in ApoE-deficient mice. After vascular injury, all animals were fed with high-cholesterol chow for 6 weeks. Edoxaban at 15 mg/kg was orally administered to the mice 1 h before (n = 10) or 1 h after (n = 9) ferric chloride injury, and thereafter 10 mg/kg edoxaban was orally administered b.i.d. for 6 weeks. Thrombus formation and neointimal hyperplasia were evaluated. Treatment with 15 mg/kg edoxaban before vascular injury almost completely inhibited thrombus formation, and following chronic administration of edoxaban significantly suppressed neointimal hyperplasia. In the mice treated with edoxaban after vascular injury, there was wide interindividual variability. In some mice (four out of nine) the neointimal hyperplasia was inhibited like in edoxaban-pretreated mice, but there was no statistical difference compared with control. This study demonstrated that inhibition of the coagulation and thrombosis by edoxaban ameliorated neointimal hyperplasia caused by vascular injury and high-cholesterol diets in ApoE-deficient mice. This suggests that factor Xa has a crucial role in the formation of neointima following vascular injury.The abstract should be followed by 3-4 bullet points that highlight major findings. The final bullet point should emphasize future directions for research.

The coagulation system in atherothrombosis: Implications for new therapeutic strategies

Clinical manifestations of atherosclerotic disease include coronary artery disease (CAD), peripheral artery disease (PAD), and stroke. Although the role of platelets is well established, evidence is now accumulating on the contribution of coagulation proteins to the processes of atherosclerosis and atherothrombosis. Coagulation proteins not only play a role in fibrin formation and platelet activation, but also mediate various biological and pathophysiologic processes through activation of protease-activated-receptors (PARs). Thus far, secondary prevention in patients with CAD/PAD has been the domain of antiplatelet therapy, however, residual atherothrombotic risks remain substantial. Therefore, combining antiplatelet and anticoagulant therapy has gained more attention. Recently, net clinical benefit of combining aspirin with low-dose rivaroxaban in patients with stable atherosclerotic disease has been demonstrated. In this review, based on the State of the Art lecture "Clotting factors and atherothrombosis" presented at the ISTH Congress 2017, we highlight the role of coagulation proteins in the pathophysiology of atherothrombosis, and specifically focus on therapeutic strategies to decrease atherothrombotic events by optimization of vascular protection.

Influence of vitamin K antagonists and direct oral anticoagulation on coronary artery disease: A CTA analysis

OBJECTIVE

Vitamin K antagonists (VKA) are associated with increased vascular calcification which may lead to an elevated cardiovascular risk. If the direct anticoagulants (DOACs) have similar negative vascular effects is unknown. We evaluated the influence of different anticoagulation strategies on coronary artery disease (CAD) using coronary computed tomography angiography (CTA).

METHODS

Overall 702 consecutive patients with non-valvular atrial fibrillation (AF) who underwent CTA for AF ablation planning were enrolled and stratified according to their anticoagulation into VKA, DOAC (all agents) and a control group without oral anticoagulation. Patients were propensity score matched 1:1:1, significant structural heart disease and comorbidities were excluded. CT images were evaluated for plaque burden (calcium score, segment involvement score (SIS) and non-calcified SIS, stenosis grading) and plaque morphology (high risk plaque features: low attenuation, positive remodeling, napkin-ring sign, spotty calcification).

RESULTS

Final analysis included 303 patients (101 patients each group) and showed increased overall plaque burden in patients using VKA compared to DOAC users and the control group (mean affected segments 2.58 vs 1.58 vs 2.100, p = 0.008), and a higher prevalence of high-risk plaque (HRP) features (42.6% vs 13.9% vs 26.7%, p < 0.0001). Patients treated with DOACs did not differ in conventional CT findings from the control group and showed an even lower prevalence of selected HRP features compared to the control group: low-attenuation plaques (4.0% vs. 14.4%, p = 0.014) and napkin-ring sign (0 vs. 5.0%, p = 0.029).

CONCLUSION

Vitamin K antagonists are associated with a higher plaque burden and increased high-risk plaque features, whereas DOACs may yield a benefit in cardiovascular atherosclerosis.

Atrial thrombogenesis in atrial fibrillation : Results from atrial fibrillation models and AF-patients

Atrial fibrillation (AF) is the most common cause of thromboembolic complications. The risk of suffering a thromboembolic complication depends on the accompanying cardiac risk factors and the patient's age. For patients who have an increased risk, which is now classified using the CHA2DS2-VASc score, initiation of long-term oral anticoagulation is the first-line treatment. In AF, thrombi arise in the left atrial appendage. The present review will summarize the basic pathophysiology of thrombogenesis in AF and will provide the molecular basis of a process called prothrombotic endocardial remodeling. Despite oral anticoagulation being a central component of therapy, the present results can be used to support concomitant therapy with statins, angiotensin II blockers, etc. to inhibit atrial thromogenesis.

Determinants of impaired renal and vascular function are associated with elevated levels of procoagulant factors in the general population

Essentials Why venous thrombosis is more prevalent in chronic kidney disease is unclear. We investigated whether renal and vascular function are associated with hypercoagulability. Coagulation factors showed a procoagulant shift with impaired renal and vascular function. This suggests that renal and vascular function play a role in the etiology of thrombosis.

SUMMARY

Background Impaired renal and vascular function have been associated with venous thrombosis, but the mechanism is unclear. Objectives We investigated whether estimated glomerular filtration rate (eGFR), urinary albumin-creatinine ratio (UACR), and pulse wave velocity (PWV) are associated with a procoagulant state. Methods In this cross-sectional analysis of the NEO Study, eGFR, UACR, fibrinogen, and coagulation factors (F)VIII, FIX and FXI were determined in all participants (n = 6536), and PWV was assessed in a random subset (n = 2433). eGFR, UACR and PWV were analyzed continuously and per percentile: per six categories for eGFR (> 50th [reference] to < 1st) and UACR (< 50th [reference] to > 99th), and per four categories (< 50th [reference] to > 95th percentile) for PWV. Linear regression was used and adjusted for age, sex, total body fat, smoking, education, ethnicity, total cholesterol, C-reactive protein (CRP) and vitamin K antagonists use (FIX). Results Mean age was 55.6 years, mean eGFR 86.0 (12SD) mL 1.73 m- ² and median UACR 0.4 mg mmol-1 (25th, 75th percentile; 0.3, 0.7). All coagulation factors showed a procoagulant shift with lower renal function and albuminuria. For example, FVIII was 22 IU dL-1 (95% CI, 13-32) higher in the eGFR < 1st percentile compared with the > 50th percentile, and FVIII was 12 IU dL-1 (95% CI, 3-22) higher in the UACR > 99th percentile compared with the < 50th percentile. PWV was positively associated with coagulation factors FIX and FXI in continuous analysis; per m/s difference in PWV, FIX was 2.0 IU dL-1 (95% CI, 0.70-3.2) higher. Conclusions Impaired renal and vascular function was associated with higher levels of coagulation factors, underlining the role of renal function and vascular function in the development of venous thrombosis.

Sex difference in clot lysability and association to coronary artery calcification

Background

Incidence and prevalence of cardiovascular disease (CVD) differ between sexes, and women experience CVD later than men. Changes in fibrin clot lysability are associated with CVD, and the present study addresses sex differences in fibrin clot lysability in asymptomatic middle-aged individuals and the relation to coronary artery calcification (CAC).

Methods

Participants free of morbidities and medication, N = 163, were randomly chosen from a national registry among citizens, 50 or 60 years of age, and were followed for 5 years. CAC was determined by the Agatston (Ag) score both at baseline and at follow-up. Based on the changes in Ag, the population was divided into two groups: ΔAg = 0 U or ΔAg > 0 U. Fibrin clot analyses were based on turbidimetric methods.

Results

At baseline, 116 women and 97 men were included; 84 women and 79 men completed the 5-year follow-up (77%). Independently of covariates, women with ΔAg > 0 had reduced mean (SD) fibrin lysability at follow-up, 40.2% (15.9), both in comparison to baseline, 47.8% (20.4), p = 0.001, to women with ΔAg = 0 U, 51.2% (24.5), p = 0.028, and to men with ΔAg > 0 U, 54.4% (21.0), p = 0.002.

Conclusions

Fibrin clot lysability changes over time with considerable sex differences. Women with progression of CAC have reduced fibrin clot lysability compared to men, indicating a sex-specific association between morphological vessel wall changes and fibrin clot lysability.

Novel Direct Anticoagulants and Atherosclerosis

Coagulation factors can affect cellular processes that include inflammatory signaling by acting on endothelial protease activated receptors, vascular smooth muscle and inflammatory cells beyond the coagulation cascade. This is important in the pathogenesis of atherosclerosis. Accordingly, experimental data points to beneficial effects of coagulation protease inhibitors on the attenuation of atherosclerosis progression in animal models. However, available clinical data do not support the use of anticoagulants as an add-on treatment of atherosclerosis. New clinical studies are needed with a better selection of patients to clarify the role of novel direct anticoagulants in the management of atherosclerosis.

Atherothrombosis and Thromboembolism: Position Paper from the Second Maastricht Consensus Conference on Thrombosis

Atherothrombosis is a leading cause of cardiovascular mortality and long-term morbidity. Platelets and coagulation proteases, interacting with circulating cells and in different vascular beds, modify several complex pathologies including atherosclerosis. In the second Maastricht Consensus Conference on Thrombosis, this theme was addressed by diverse scientists from bench to bedside. All presentations were discussed with audience members and the results of these discussions were incorporated in the final document that presents a state-of-the-art reflection of expert opinions and consensus recommendations regarding the following five topics: 1. Risk factors, biomarkers and plaque instability: In atherothrombosis research, more focus on the contribution of specific risk factors like ectopic fat needs to be considered; definitions of atherothrombosis are important distinguishing different phases of disease, including plaque (in)stability; proteomic and metabolomics data are to be added to genetic information. 2. Circulating cells including platelets and atherothrombosis: Mechanisms of leukocyte and macrophage plasticity, migration, and transformation in murine atherosclerosis need to be considered; disease mechanism-based biomarkers need to be identified; experimental systems are needed that incorporate whole-blood flow to understand how red blood cells influence thrombus formation and stability; knowledge on platelet heterogeneity and priming conditions needs to be translated toward the in vivo situation. 3. Coagulation proteases, fibrin(ogen) and thrombus formation: The role of factor (F) XI in thrombosis including the lower margins of this factor related to safe and effective antithrombotic therapy needs to be established; FXI is a key regulator in linking platelets, thrombin generation, and inflammatory mechanisms in a renin-angiotensin dependent manner; however, the impact on thrombin-dependent PAR signaling needs further study; the fundamental mechanisms in FXIII biology and biochemistry and its impact on thrombus biophysical characteristics need to be explored; the interactions of red cells and fibrin formation and its consequences for thrombus formation and lysis need to be addressed. Platelet-fibrin interactions are pivotal determinants of clot formation and stability with potential therapeutic consequences. 4. Preventive and acute treatment of atherothrombosis and arterial embolism; novel ways and tailoring? The role of protease-activated receptor (PAR)-4 vis à vis PAR-1 as target for antithrombotic therapy merits study; ongoing trials on platelet function test-based antiplatelet therapy adjustment support development of practically feasible tests; risk scores for patients with atrial fibrillation need refinement, taking new biomarkers including coagulation into account; risk scores that consider organ system differences in bleeding may have added value; all forms of oral anticoagulant treatment require better organization, including education and emergency access; laboratory testing still needs rapidly available sensitive tests with short turnaround time. 5. Pleiotropy of coagulation proteases, thrombus resolution and ischaemia-reperfusion: Biobanks specifically for thrombus storage and analysis are needed; further studies on novel modified activated protein C-based agents are required including its cytoprotective properties; new avenues for optimizing treatment of patients with ischaemic stroke are needed, also including novel agents that modify fibrinolytic activity (aimed at plasminogen activator inhibitor-1 and thrombin activatable fibrinolysis inhibitor.

Endothelial Cell-Derived Von Willebrand Factor, But Not Platelet-Derived, Promotes Atherosclerosis in Apolipoprotein E-Deficient Mice

OBJECTIVE

VWF (von Willebrand factor) is synthesized by endothelial cells and megakaryocytes and is known to contribute to atherosclerosis. In vitro studies suggest that platelet-derived VWF (Plt-VWF) is biochemically and functionally different from endothelial cell-derived VWF (EC-VWF). We determined the role of different pools of VWF in the pathophysiology of atherosclerosis.

APPROACH AND RESULTS

Using bone marrow transplantation, we generated chimeric Plt-VWF, EC-VWF, and Plt-VWF mice lacking a disintegrin and metalloprotease with thrombospondin type I repeats-13 in platelets and plasma on apolipoprotein E-deficient (Apoe^-/-) background. Controls were chimeric Apoe^-/- mice transplanted with bone marrow from Apoe^-/- mice (wild type) and Vwf^-/-Apoe^-/- mice transplanted with bone marrow from Vwf^-/-Apoe^-/- mice (VWF-knock out). Susceptibility to atherosclerosis was evaluated in whole aortae and cross-sections of the aortic sinus in female mice fed a high-fat Western diet for 14 weeks. VWF-knock out, Plt-VWF, and Plt-VWF mice lacking a disintegrin and metalloprotease with thrombospondin type I repeats-13 exhibited reduced plaque size characterized by smaller necrotic cores, reduced neutrophil and monocytes/macrophages content, decreased MMP9 (matrix metalloproteinase), MMP2, and CX₃CL1 (chemokine [C-X3-C motif] ligand 1)-positive area, and abundant interstitial collagen (P<0.05 versus wild-type or EC-VWF mice). Atherosclerotic lesion size and composition were comparable between wild-type or EC-VWF mice. Together these findings suggest that EC-VWF, but not Plt-VWF, promotes atherosclerosis exacerbation. Furthermore, intravital microscopy experiments revealed that EC-VWF, but not Plt-VWF, contributes to platelet and leukocyte adhesion under inflammatory conditions at the arterial shear rate.

CONCLUSIONS

EC-VWF, but not Plt-VWF, contributes to VWF-dependent atherosclerosis by promoting platelet adhesion and vascular inflammation. Plt-VWF even in the absence of a disintegrin and metalloprotease with thrombospondin type I repeats-13, both in platelet and plasma, was not sufficient to promote atherosclerosis.

Proteomic Profiling for Cardiovascular Biomarker Discovery in Orthostatic Hypotension

Orthostatic hypotension (OH) has been linked with higher incidence of cardiovascular disease, but little is known about the mechanisms behind this association. We aimed to identify cardiovascular disease biomarkers associated with OH through a proteomic profiling approach. Seven hundred seventy-eight patients with unexplained syncope or orthostatic intolerance underwent head-up tilt test and supine blood samples. Of these, 220 met diagnostic criteria of OH, and 179 demonstrated normal hemodynamic response during head-up tilt test. Blood samples were analyzed by antibody-based Proximity Extension Assay technique simultaneously measuring 92 cardiovascular disease-related human protein biomarkers. The discovery algorithm was a sequential 2-step process of biomarker signature identification by supervised, multivariate, principal component analysis and verification by univariate ANOVA with Bonferroni correction. Patients with OH were older (67 versus 60 years; P<0.001) and more likely to be women (48% versus 41%; P>0.001) but did not differ from OH-negative patients in medical history. Principal component analysis identified MMP-7 (matrix metalloproteinase-7), TM (thrombomodulin), MB (myoglobin), TIM-1 (T-cell immunoglobulin and mucin domain-1), CASP-8 (caspase-8), CXCL-1 (C-X-C motif chemokine-1), Dkk-1 (dickkopf-related protein-1), lectin-like LOX-1 (oxidized low-density lipoprotein receptor-1), PlGF (placenta growth factor), PAR-1 (proteinase-activated receptor-1), and MCP-1 (monocyte chemotactic protein-1) as the most robust proteomic signature for OH. From this proteomic feature selection, MMP-7 and TIM-1 met Bonferroni-adjusted significance criteria in univariate and multivariate regression analyses. Proteomic profiling in OH reveals a biomarker signature of atherothrombosis and inflammation. Circulating levels of MMP-7 and TIM-1 are independently associated with OH and may be involved in cardiovascular disease promotion.

Apixaban

Apixaban is a potent reversible inhibitor of the activated human coagulation factor X. This new oral anticoagulant has favourable pharmacokinetic and pharmocodynamic properties which include a concentration-dependent anticoagulant effect, good oral bioavailability, balanced elimination and excretion, infrequent drug or food interactions, and the lack of liver toxicity. Apixaban has already completed a large part of its phase 3 clinical trial programme. In the ARISTOTLE study, which focused on stroke prevention in atrial fibrillation, apixaban showed a balanced efficacy and safety profile, being superior to warfarin both in the prevention of strokes and in the risk of causing major bleeding. A further trial related to this indication, AVERROES, demonstrated the clear superiority of apixaban compared to aspirin treatment. In the primary prophylaxis of venous thromboembolism after orthopaedic surgery, apixaban successfully completed the ADVANCE study programme and was approved in Europe for patients undergoing elective hip or knee replacement. The results of the AMPLIFY and AMPLIFY- EXT studies will soon show whether the inhibitor is also effective in the treatment and secondary prophylaxis after acute deep vein thrombosis and pulmonary embolism. On the other hand, the use of apixaban in the primary prophylaxis of venous thrombosis in hospitalised medical patients, and its administration on top of antiplatelet therapy to patients who have suffered an acute coronary syndrome, have not received support by the results of ADOPT and APPRAISE-II, respectively. In conclusion, on the basis of the available evidence, apixaban appears to be a valuable therapeutic option for the prevention of venous thrombosis and embolic stroke.

Inhibition of activated factor X by rivaroxaban attenuates neointima formation after wire-mediated vascular injury

Accumulating evidence suggests that activated factor X (FXa), a key coagulation factor, plays an important role in the development of vascular inflammation through activation of many cell types. Here, we investigated whether pharmacological blockade of FXa attenuates neointima formation after wire-mediated vascular injury. Transluminal femoral artery injury was induced in C57BL/6 mice by inserting a straight wire. Rivaroxaban (5mg/kg/day), a direct FXa inhibitor, was administered from one week before surgery until killed. At four weeks after surgery, rivaroxaban significantly attenuated neointima formation in the injured arteries compared with control (P<0.01). Plasma lipid levels and blood pressure were similar between the rivaroxaban-treated group and non-treated group. Quantitative RT-PCR analyses demonstrated that rivaroxaban reduced the expression of inflammatory molecules (e.g., IL-1β and TNF-α) in injured arteries at seven days after surgery (P<0.05, respectively). In vitro experiments using mouse peritoneal macrophages demonstrated that FXa increased the expression of inflammatory molecules (e.g., IL-1β and TNF-α), which was blocked in the presence of rivaroxaban (P<0.05). Also, in vitro experiments using rat vascular smooth muscle cells (VSMC) demonstrated that FXa promoted both proliferation and migration of this cell type (P<0.05), which were blocked in the presence of rivaroxaban. Inhibition of FXa by rivaroxaban attenuates neointima formation after wire-mediated vascular injury through inhibition of inflammatory activation of macrophages and VSMC.

Procoagulant reactivity to laboratory acute mental stress in Africans and Caucasians, and its relation to depressive symptoms: The SABPA Study

The risk of cardiovascular disease is dramatically increasing in Africans (black). The prothrombotic stress response contributes to atherothrombotic disease and is modulated by depressive symptoms. We examined coagulation reactivity to acute mental stress and its relation to psychological well-being in Africans relative to Caucasians (white). A total of 102 African and 165 Caucasian school teachers underwent the Stroop Color-Word Conflict test. Circulating levels of von Willebrand factor (VWF) antigen, fibrinogen, and D-dimer were measured before and after the Stroop. Cardiovascular reactivity measures were also obtained. All participants completed the Patient Health Questionnaire-9 and the General Health Questionnaire-28 for the assessment of depressive symptoms and total psychological distress, respectively. After controlling for covariates, resting levels of VWF, fibrinogen, and D-dimer were higher in Africans than in Caucasians (all p-values ≤0.006). Depressive symptoms and psychological distress were not significantly associated with resting coagulation measures. Stress reactivity in VWF (p<0.001) and fibrinogen (p=0.016), but not in D-dimer (p=0.27), were decreased in Africans relative to Caucasians with Africans showing greater reactivity of total peripheral resistance (p=0.017). Depressive symptoms, but not general psychological distress, were associated with greater VWF increase (p=0.029) and greater fibrinogen decrease (p=0.030) in Africans relative to Caucasians. In conclusion, Africans showed greater hypercoagulability at rest but diminished procoagulant reactivity to acute mental stress when compared with Caucasians. Ethnic differences in the vascular adrenergic stress response might partially explain this finding. Depressive symptoms were associated with exaggerated VWF reactivity in Africans relative to Caucasians. The clinical implications of these findings for Africans need further study.

Association between statin use and plasma D-dimer levels

D-dimers, specific breakdown fragments of cross-linked fibrin, are generally used as circulating markers of activated coagulation. Statins influence haemostatic factors, but their effect on plasma D-dimer levels is controversial. Therefore, the aim of this meta-analysis was to evaluate the association between statin therapy and plasma D-dimer levels. We searched PubMed, Web of Science, Cochrane Library, Scopus and EMBASE (up to September 25, 2014) to identify randomised controlled trials (RCTs) investigating the impact of statin therapy on plasma D-dimer levels. Two independent reviewers extracted data on study characteristics, methods and outcomes. Meta-analysis of data from nine RCTs with 1,165 participants showed a significant effect of statin therapy in reducing plasma D-dimer levels (standardised mean difference [SMD]: –0.988 µg/ml, 95 % confidence interval [CI]: –1.590 – –0.385, p=0.001). The effect size was robust in sensitivity analysis and omission of no single study significantly changed the overall estimated effect size. In the subgroup analysis, the effect of statins on plasma D-dimer levels was significant only in the subsets of studies with treatment duration ≥ 12 weeks (SMD: –0.761 µg/ml, 95 %CI: –1.163– –0.360; p< 0.001), and for lipophilic statins (atorvastatin and simvastatin) (SMD: –1.364 µg/ml, 95 % CI: –2.202– –0.526; p=0.001). Hydrophilic statins (pravastatin and rosuvastatin) did not significantly reduce plasma D-dimer levels (SMD: –0.237 µg/ml, 95 %CI: –1.140–0.665, p=0.606). This meta-analysis of RCTs suggests a decrease of plasma D-dimer levels after three months of statin therapy, and especially after treatment with lipophilic statins. Well-designed trials are required to validate these results.

Note: The review process for this paper was fully handled by Christian Weber, Editor in Chief.

Higher Platelet-to-Lymphocyte Ratio Increased the Risk of Sarcopenia in the Community-Dwelling Older Adults

The platelet-to-lymphocyte ratio (PLR) has been extensively studied in oncologic diseases. However, the correlation between PLR and sarcopenia remains unknown. In this cross-sectional analysis, we enrolled 3,671 non-institutionalized individuals from the National Health and Nutrition Examination Survey (NHANES) III (1988–1994) aged ≥60 years and whose complete blood counts (CBCs), body composition measurements, and related demographic information was available. Skeletal muscle mass was assessed using a previously published equation (including age, sex, height, and bioelectrical impedance analysis). PLR values were estimated based on laboratory data. Multiple linear and logistic regression analyses, quartile-based stratified odds ratio comparisons, and trend tests were performed. Elevations in serum PLR values were significantly associated with sarcopenia status and negatively associated with skeletal muscle index. After additionally adjusting for other covariates, the significant negative correlation remained; moreover, participants with highest serum PLR values (≥155) had 2.36 times greater risk of sarcopenia than those with lowest PLR values (<90; odds ratio (OR) = 2.36; 95% confidence interval (CI): 1.21–3.31; p < 0.01). Higher PLR levels are associated with a greater risk of sarcopenia in geriatric populations. Thus, PLR as an inexpensive and easily measurable parameter can be considered as an inflammatory biomarker for sarcopenia.

Targeting factor Xa and thrombin: impact on coagulation and beyond

Great advances have been made in recent years in understanding the haemostatic system and the molecular and cellular basis of thrombus formation. Although directly targeting factor Xa or thrombin (factor IIa) for effective anticoagulation is now well established, evidence has emerged suggesting that factor Xa and thrombin are involved in other physiological and pathophysiological cellular processes, including inflammation. These non-haemostatic activities of factor Xa and thrombin are predominantly mediated via the activation of proteinaseactivated receptors. Studies have indicated a potential role of coagulation proteins (including factor Xa and thrombin) in the progression of disease conditions such as atherothrombosis. Preclinical studies have provided evidence for the effects of direct factor Xa or direct thrombin inhibition beyond anticoagulation, including anti-inflammatory activities and atherosclerotic plaque stabilisation. In this article, the non-haemostatic activities of factor Xa and thrombin and the effects of direct inhibition of these coagulation factors on these activities are summarised. In addition, the potential roles of factor Xa and thrombin in atherosclerosis and atherothrombosis are explored and the cardiovascular profiles of rivaroxaban, apixaban and dabigatran etexilate observed in phase III clinical studies are discussed.

Elderly apolipoprotein E‑/‑ mice with advanced atherosclerotic lesions in the aorta do not develop Alzheimer's disease-like pathologies

Atherosclerosis and Alzheimer's disease (AD) are a major cause of morbidity and mortality in Western societies. These diseases share common risk factors, which are exhibited in old age, including hypertension, diabetes, hypercholesterolemia and apolipoprotein (Apo) ε4 allele. We previously demonstrated that factor XI (FXI) deficiency in mice reduced the atherosclerotic plaque area in coronary sinuses and the aortic arch. This led us to investigate whether FXI deficiency in elderly ApoE knockout (KO) mice would decrease pathological alterations compatible with atherosclerosis and AD. The present study used ApoE/factor XI double KO (ApoE/FXI DKO) mice aged 64 weeks and age‑matched ApoE KO mice to serve as a control group. The ApoE KO mice developed an advanced atherosclerotic lesion area in the aortic arch, which was reduced by 33% in the DKO mice. However, neither atherosclerosis nor AD‑associated pathological alterations in the elderly mice brains were observed in either the DKO mice or the ApoE KO mice. The results advocate a dichotomy between the brain and peripheral blood vessels. Therefore, the ApoE KO and DKO mice cannot serve as mouse models for studying AD or pathological brain changes compatible with atherosclerosis. The mechanism by which ApoE KO protects against brain pathology should be further studied as it may prove helpful for future treatment of senile dementia.

Plasma proteomics reveals coagulation, inflammation, and metabolic shifts in H-type hypertension patients with and without acute ischemic stroke

Systematic profiling of a larger portion of circulating plasma proteome provide opportunities for unbiased discovery of novel markers to improve diagnostic, therapeutic, or predictive accuracy. This study aimed to identify differentially expressed proteins (DEPs) in plasma that could provide overall insight into the molecular changes of both H- type hypertension (HH) and HH-related acute ischemic stroke (AIS). This study used an iTRAQ-based LC-MS/MS proteomics approach to screen for plasma DEPs in HH patients with and without AIS, and controls. After excluding highly abundant plasma proteins, more than 600 proteins, and their relative levels, were identified. Of these, 26 DEPs, each showing > 1.2-fold change, were identified in HH and HH-related AIS patients compared with controls. Bioinformatics analysis revealed that these DEPs were enriched in 21 functional gene ontology items; “blood coagulation” was the most predominant pathway showing enrichment. Of these, eight DEPs were located in the hub position of networks involved with protein-protein interactions. AT-3, CRP, ApoB, and AHSG were further validated in each group by enzyme-linked immune sorbent assays. Comparing HH-related AIS with HH, the areas under the curve for AT-3, CRP, ApoB, and AHSG were 0.698, 0.892, 0.626, and 0.847, respectively. This proteomic profiling study provided enhanced pathophysiological understanding of the regulatory processes involved in coagulation, inflammation, and metabolism, and identified a panel of novel biomarkers for detecting HH-related AIS during its pre-stroke stage.

Analysis of Recurrent Stroke Volume and Prognosis between Warfarin and Four Non-Vitamin K Antagonist Oral Anticoagulants' Administration for Secondary Prevention of Stroke

OBJECTIVE

We investigated recurrent stroke volume with nonvalvular atrial fibrillation (NVAF) patients treated with non-vitamin K antagonist oral anticoagulants (NOACs) about clinical backgrounds and number of recurrent stroke.

METHODS

We administered 4 NOACs, dabigatran, rivaroxaban, apixaban, and edoxaban in 101 postcardioembolic strokes with NVAF. In a retrospective study, we measured recurrent stroke volume with magnetic resonance imaging volumetric software and compared them between 10 vitamin K anticoagulant (VKA: warfarin) cases and 13 NOAC cases under anticoagulant therapy.

RESULTS

Of 101 cases, 31 were started with a VKA and switched to NOACs after 10 recurrent strokes. Other 70 cases were directly started with NOACs and 13 cases with NOACs as first anticoagulants had recurrent stroke. The frequency of recurrent stroke during anticoagulant therapy is not different between the VKA group and the 3 NOACs group. Recurrent stroke volume is significantly larger in the VKA group (26.4 cm³) than in the NOACs group (1.2 cm³).

CONCLUSIONS

Secondary prevention with NOACs after stroke might be more beneficial than a VKA by reducing recurrent infarct volume.

Prognostic value of platelet-to-lymphocyte ratios among critically ill patients with acute kidney injury

Background

Inflammation plays an important role in the initiation and progression of acute kidney injury (AKI). However, evidence regarding the prognostic effect of the platelet-to-lymphocyte ratio (PLR), a novel systemic inflammation marker, among patients with AKI is scarce. In this study, we investigated the value of the PLR in predicting the outcomes of critically ill patients with AKI.

Methods

Patient data were extracted from the Multiparameter Intelligent Monitoring in Intensive Care Database III version 1.3. PLR cutoff values were determined using smooth curve fitting or quintiles and were used to categorize the subjects into groups. The clinical outcomes were 30-day and 90-day mortality in the intensive care unit (ICU). Cox proportional hazards models were used to evaluate the association between the PLR and survival.

Results

A total of 10,859 ICU patients with AKI were enrolled. A total of 2277 thirty-day and 3112 ninety-day deaths occurred. A U-shaped relationship was observed between the PLR and both 90-day and 30-day mortality, with the lowest risk being at values ranging from 90 to 311. The adjusted HR (95% CI) values for 90-day mortality given risk values < 90 and > 311 were 1.25 (1.12–1.39) and 1.19 (1.08–1.31), respectively. Similar trends were observed for 30-day mortality or when quintiles were used to group patients according to the PLR. Statistically significant interactions were found between the PLR and both age and heart rate. Younger patients (aged < 65 years) and those with more rapid heart rates (≥89.4 beats per minute) tended to have poorer prognoses only when the PLR was < 90, whereas older patients (aged ≥ 65 years) and those with slower heart rates (<89.4 beats per minute) had higher risk only when the PLR was > 311 (P < 0.001 for age and P < 0.001 for heart rate).

Conclusions

The preoperative PLR was associated in a U-shaped pattern with survival among patients with AKI. The PLR appears to be a novel, independent prognostic marker of outcomes in critically ill patients with AKI.

Cytoprotective activated protein C averts Nlrp3 inflammasome-induced ischemia-reperfusion injury via mTORC1 inhibition

Cytoprotection by activated protein C (aPC) after ischemia-reperfusion injury (IRI) is associated with apoptosis inhibition. However, IRI is hallmarked by inflammation, and hence, cell-death forms disjunct from immunologically silent apoptosis are, in theory, more likely to be relevant. Because pyroptosis (ie, cell death resulting from inflammasome activation) is typically observed in IRI, we speculated that aPC ameliorates IRI by inhibiting inflammasome activation. Here we analyzed the impact of aPC on inflammasome activity in myocardial and renal IRIs. aPC treatment before or after myocardial IRI reduced infarct size and Nlrp3 inflammasome activation in mice. Kinetic in vivo analyses revealed that Nlrp3 inflammasome activation preceded myocardial injury and apoptosis, corroborating a pathogenic role of the Nlrp3 inflammasome. The constitutively active Nlrp3^A350V mutation abolished the protective effect of aPC, demonstrating that Nlrp3 suppression is required for aPC-mediated protection from IRI. In vitro aPC inhibited inflammasome activation in macrophages, cardiomyocytes, and cardiac fibroblasts via proteinase-activated receptor 1 (PAR-1) and mammalian target of rapamycin complex 1 (mTORC1) signaling. Accordingly, inhibiting PAR-1 signaling, but not the anticoagulant properties of aPC, abolished the ability of aPC to restrict Nlrp3 inflammasome activity and tissue damage in myocardial IRI. Targeting biased PAR-1 signaling via parmodulin-2 restricted mTORC1 and Nlrp3 inflammasome activation and limited myocardial IRI as efficiently as aPC. The relevance of aPC-mediated Nlrp3 inflammasome suppression after IRI was corroborated in renal IRI, where the tissue protective effect of aPC was likewise dependent on Nlrp3 inflammasome suppression. These studies reveal that aPC protects from IRI by restricting mTORC1-dependent inflammasome activation and that mimicking biased aPC PAR-1 signaling using parmodulins may be a feasible therapeutic approach to combat IRI.

Efficacy of Laropiprant in Minimizing Brain Injury Following Experimental Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is one of the most devastating and disabling forms of stroke, yet effective treatments are still lacking. Prostaglandins and their receptors have been implicated in playing vital roles in ICH outcomes. Recently, laropiprant, a DP1 receptor antagonist, has been used in combination with niacin to abolish the prostaglandin D2-(PGD2)-induced flushing. Here, we test the hypothesis that laropiprant limits bleeding and rescues the brain from ICH. Wildtype (WT) and DP1-/- mice were subjected ICH and neurologic deficits and hemorrhagic lesion outcomes were evaluated at 72 hours after the ICH. To test the therapeutic potential of laropiprant, WT mice subjected to ICH were treated with laropiprant at 1 hour after the ICH. The putative effect of laropiprant on limiting hematoma expansion was tested by an in vivo tail bleeding cessation method and an ex vivo coagulation method. Finally, the roles of laropiprant on gliosis and iron accumulation were also investigated. A significant decrease in the injury volume was observed in DP1-/- as well as laropiprant-treated WT mice. The tail bleeding time was significantly lower in laropiprant group as compared with the vehicle group. Significantly lower Iba-1 and Perls' iron staining in DP1-/- and laropiprant-treated WT groups were observed. Altogether, the data suggest that laropiprant treatment post-ICH attenuates brain damage by targeting primary as well as secondary injuries.

Association Between High-Sensitivity Cardiac Troponin I and Cardiac Events in Elderly Women

Background

Elderly women are at high risk of coronary heart disease (CHD) and heart failure. High‐sensitivity assays allow detection of cardiac troponin I (hsTnI) well below diagnostic cutoffs for acute coronary syndrome. We investigated the association between these levels with future cardiac events in community‐based ambulant white women aged over 70 years initially recruited for a 5‐year randomized, controlled trial of calcium supplements.

Methods and Results

This was a prospective study of 1081 elderly women without clinical CHD at baseline (1998) or hsTnI above the diagnostic cutoffs for acute coronary syndrome with 14.5‐year follow‐up hospitalization and mortality (events). Two hundred forty‐three (22%) women had CHD events, 163 (15%) myocardial infarction or CHD death (hard CHD), and 109 (10%) heart failure. In 99.6% of available serum samples, hsTnI was above the level of detection (median, 4.5 ng/L; interquartile range, 3.6–5.8). After adjusting for Framingham risk factors, each SD natural log‐transformed hsTnI increase was associated with an increased hazard for CHD (hazard ratio, 1.34; 95% CI, 1.18–1.53; P<0.001) hard CHD (hazard ratio, 1.51; 95% CI, 1.29–1.76; P<0.001), and heart failure (hazard ratio, 1.65; 95% CI, 1.36–1.99; P<0.001). Step‐wise increases in relative hazards were observed with increasing quartiles of hsTnI (P for trend, <0.001), whereas the addition of hsTnI to conventional risk factors modestly improved discrimination indices: Harrell's c‐statistic, net reclassification, and integrated discrimination (P<0.05).

Conclusions

Cardiac troponin I is independently associated with future cardiac events in elderly women without apparent clinical manifestations. The addition of cardiac troponin I to conventional risk factors may modestly improve risk prediction in this setting.

Triggering Receptor Expressed on Myeloid cells-1: a new player in platelet aggregation

Triggering Receptor Expressed on Myeloid cells-1 (TREM-1) is an immunoreceptor initially known to be expressed on neutrophils and monocytes/macrophages. TREM-1 acts as an amplifier of the inflammatory response during both infectious and aseptic inflammatory diseases. Another member of the TREM family, The Triggering receptor expressed on myeloid cells Like Transcript-1 (TLT-1) is exclusively expressed in platelets and promotes platelet aggregation. As the gene that encodes for TLT-1 is located in the TREM-1 gene cluster, this prompted us to investigate the expression of TREM-1 on platelets. Here we show that TREM-1 is constitutively expressed in α-granules and mobilised at the membrane upon platelet activation. Pharmacologic inhibition of TREM-1 reduces platelet activation as well as platelet aggregation induced by collagen, ADP, and thrombin in human platelets. Aggregation is similarly impaired in platelets from Trem-1^-/- mice. In vivo, TREM-1 inhibition decreases thrombus formation in a carotid artery model of thrombosis and protects mice during pulmonary embolism without excessive bleeding. These findings suggest that TREM-1 inhibition could be useful adducts in antiplatelet therapies.

Homeostatic effects of coagulation protease-dependent signaling and protease activated receptors

A homeostatic function of the coagulation system in regard to hemostasis is well established. Homeostasis of blood coagulation depends partially on protease activated receptor (PAR)-signaling. Beyond coagulation proteases, numerous other soluble and cell-bound proteases convey cellular effects via PAR signaling. As we learn more about the mechanisms underlying cell-, tissue-, and context-specific PAR signaling, we concurrently gain new insights into physiological and pathophysiological functions of PARs. In this regard, regulation of cell and tissue homeostasis by PAR signaling is an evolving scheme. Akin to the control of blood clotting per se (the fibrin-platelet interaction) coagulation proteases coordinately regulate cell- and tissue-specific functions. This review summarizes recent insights into homeostatic regulation through PAR signaling, focusing on blood coagulation proteases. Considering the common use of drugs altering coagulation protease activity through either broad or targeted inhibitory activities, and the advent of PAR modulating drugs, an in-depth understanding of the mechanisms through which coagulation proteases and PAR signaling regulate not only hemostasis, but also cell and tissue homeostasis is required.

Coagulation factor and protease pathways in thrombosis and cardiovascular disease

The biochemical characterisation of the proteolytic pathways that constitute blood coagulation was one of the most relevant achievements in biomedical research during the second half of the 20th century. Understanding these pathways was of crucial importance for improving global health through application in haemostasis and thrombosis pathologies. Immediately after the cloning of the genes corresponding to these proteins, mutations were discovered in them that were associated with imbalances in haemostasis. Later, the importance of coagulation pathways in other pathological processes was demonstrated, such as in atherosclerosis and inflammation, both essential processes involved in vascular disease. In the present review we evaluate the concepts that have allowed us to reach the integrated vision on coagulation that we have today. The thrombo-inflammation model encompassing these aspects includes a pivotal role for the proteases of the coagulation pathway as well as the regulatory proteins thereof. These concepts illustrate the importance of the coagulation cascade in cardiovascular pathology, not only in thrombotic processes, but also in atherosclerotic processes and in the response to ischaemia-reperfusion injury, making it a central mechanism in cardiovascular disease.

Spermine and spermidine reversed age-related cardiac deterioration in rats

Aging is the most important risk factor for cardiovascular disease (CVD). Slowing or reversing the physiological impact of heart aging may reduce morbidity and mortality associated with age-related CVD. The polyamines, spermine (SP) and spermidine (SPD) are essential for cell growth, differentiation and apoptosis, and levels of both decline with age. To explore the effects of these polyamines on heart aging, we administered SP or SPD intraperitoneally to 22- to 24-month-old rats for 6 weeks. Both treatments reversed and inhibited age-related myocardial morphology alterations, myocardial fibrosis, and cell apoptosis. Using combined proteomics and metabolomics analyses, we identified proteins and metabolites up- or downregulated by SP and SPD in aging rat hearts. SP upregulated 51 proteins and 28 metabolites while downregulating 80 proteins and 29 metabolites. SPD upregulated 44 proteins and 24 metabolites and downregulated 84 proteins and 176 metabolites. These molecules were mainly associated with immune responses, blood coagulation, lipid metabolism, and glutathione metabolism pathways. Our study provides novel molecular information on the cardioprotective effects of polyamines in the aging heart, and supports the notion that SP and SPD are potential clinical therapeutics targeting heart disease.

Increased plasma thrombin potential is associated with stable coronary artery disease: An angiographically-controlled study

INTRODUCTION

Coagulation plays a crucial role in coronary artery disease (CAD) contributing to both atherosclerotic plaque development and acute thrombotic complications, like myocardial infarction (MI). Coagulation biomarkers have been linked with ischemic heart disease, but results are still controversial.

MATERIALS AND METHODS

D-dimer and thrombin generation, two "overall" coagulation assays, were evaluated in 775 subjects with or without angiographically-proven CAD (170 CAD-free and 605 CAD, 355 of whom with history of previous MI). Subjects taking anticoagulant drugs or with any acute illness were excluded. D-dimer plasma concentration was determined by an immuno-turbidimetric assay. Thrombin generation was assessed as the ability of plasma to generate thrombin triggered by the addition of tissue factor ex-vivo by means of a chromogenic method.

RESULTS

Both D-dimer and thrombin generation parameters were associated with several traditional cardiovascular risk factors. Lag-time, time-to-peak, peak height, and Endogenous Thrombin Potential (ETP), as well as D-dimer levels, were higher in CAD patients than in CAD-free subjects. After adjustment for all the traditional risk factors, only ETP levels remained significantly associated with CAD (the highest versus the lowest tertile: OR 2.61 with 95%CI 1.14-5.99), but without improvement of C-statistic. The association of D-dimer vanished after adjustment for inflammatory markers. No difference of either D-dimer or thrombin generation parameters was found between CAD patients with or without previous MI history.

CONCLUSIONS

Our results suggest that an increased plasma thrombin potential is characteristic in patients with clinically stable CAD, irrespective of previous MI history and independent of traditional cardiovascular risk factors.

Thrombin generation test for evaluation of antiplatelet treatment in patients with coronary artery disease after percutaneous coronary intervention

To study the possibility of using thrombin generation tests in platelet-rich and platelet-poor plasma for evaluation of dual antiplatelet therapy efficacy in patients with coronary artery disease (CAD), following percutaneous coronary intervention. Venous blood was analyzed from CAD patients aged 53-75 years who had undergone percutaneous coronary intervention with stenting within one year and had been receiving standard doses of clopidogrel and aspirin (75 and 75-100 mg per day, respectively). The control group comprised age- and sex-matched subjects without clinical signs of CAD who were not receiving these drugs. Thrombin generation tests were performed in platelet-rich and platelet-poor plasma. Intravascular platelet activation, induced platelet aggregation, and routine coagulation were evaluated. Antiplatelet treatment did not influence results of routine coagulation tests or intravascular platelet activation. The dual antiplatelet therapy affects collagen-induced platelet aggregation (44 ± 2.5 vs. 7.9 ± 2.6%, р = 10^-7) and leads to decreases in endogenous thrombin potential (1900 ± 85 vs. 1740 ± 95 nM∙min, p = 0.0045), maximum thrombin concentration (134 ± 9.5 vs. 106 ± 6.5 nM, p = 4∙10^-6), and increases in time to peak thrombin (27 ± 1.5 vs. 31 ± 2 min, p = 0.0012). Decreases in thrombin generation rate showed the highest statistical significance (13 ± 2 vs. 7.9 ± 0.8 nM/min, p = 10^-8). Antiplatelet treatment did not alter thrombogram parameters for platelet-poor plasma.

Dabigatran and rivaroxaban do not affect AA- and ADP-induced platelet aggregation in patients receiving concomitant platelet inhibitors

Dabigatran and rivaroxaban are novel, vitamin K-independent oral anticoagulants (NOACs) and act via antagonism of the coagulation factor (F) IIa (dabigatran) or FXa (rivaroxaban), respectively. Compared to vitamin-K-antagonists, NOACs have shown non-inferiority of risk and benefit in patients with non valvular atrial fibrillation (AF). In clinical practice there is increasing use of NOACs combined with platelet inhibitors in patients with AF and coronary artery disease. However, whether NOACs affect the function of platelet inhibitors remains incompletely known. This observational study aimed to assess the platelet function in patients receiving dabigatran or rivaroxaban and concomitant platelet inhibitors. A single centre observational study was performed analysing the platelet aggregation of patients treated with dabigatran or rivaroxaban with or without concomitant platelet inhibitors. Measurements before the initiation of NOAC therapy served as the respective control group. Platelet aggregation was measured by multiple electrode aggregometry and was induced with adenosine diphosphate (ADP, 6.5 µM) and arachidonic acid (AA, 0.5 mM), respectively. In order to evaluate whether NOACs interact with platelet inhibition by ASA or the P2Y12-antagonist clopidogrel, 87 patients were grouped according to their concomitant antiplatelet medication. Comparing the ADP- and AA-induced platelet aggregation in patients without concomitant platelet inhibitors (n = 45) no significant differences under therapy with dabigatran (d) or rivaroxaban (r) compared to the control group (c) were observed. In patients taking clopidogrel as a concomitant platelet inhibitor (n = 21), neither dabigatran nor rivaroxaban affected the ADP-induced platelet aggregation (c 20 ± 11, d 21 ± 14, r 18 ± 8 AU*min, p = 0.200). Patients receiving dabigatran or rivaroxaban in combination with ASA (n = 42; 21 ASA only, 21 ASA + clopidogrel) showed no significant differences of the AA-induced aggregation compared to the control group (c 10 ± 8, d 9 ± 7, r 10 ± 8 AU*min, p = 0.810). The antiplatelet effects of ASA and clopidogrel monitored by AA- or ADP-induced platelet aggregation were not affected by NOAC therapy.

The Effect of Regular Intake of Dry-Cured Ham Rich in Bioactive Peptides on Inflammation, Platelet and Monocyte Activation Markers in Humans

Background and aims: Dietary studies have shown that active biopeptides provide protective health benefits, although the mediating pathways are somewhat uncertain. To throw light on this situation, we studied the effects of consuming Spanish dry-cured ham on platelet function, monocyte activation markers and the inflammatory status of healthy humans with pre-hypertension. Methods: Thirty-eight healthy volunteers with systolic blood pressure of >125 mmHg were enrolled in a two-arm crossover randomized controlled trial. Participants received 80 g/day dry-cured pork ham of >11 months proteolysis or 100 g/day cooked ham (control product) for 4 weeks followed by a 2-week washout before “crossing over” to the other treatment for 4 more weeks. Soluble markers and cytokines were analyzed by ELISA. Platelet function was assessed by measuring P-selectin expression and PAC-1 binding after ADP (adenosine diphosphate) stimulation using whole blood flow cytometry. Monocyte markers of the pathological status (adhesion, inflammatory and scavenging receptors) were also measured by flow cytometry in the three monocyte subsets after the interventional period. Results: The mean differences between dry-cured ham and cooked ham followed by a time period adjustment for plasmatic P-selectin and interleukin 6 proteins slightly failed (p = 0.062 and p = 0.049, respectively), notably increased for MCP-1 levels (p = 0.023) while VCAM-1 was not affected. Platelet function also decreased after ADP stimulation. The expression of adhesion and scavenging markers (ICAM1R, CXCR4 and TLR4) in the three subsets of monocytes was significantly higher (all p < 0.05). Conclusions: The regular consumption of biopeptides contained in the dry-cured ham but absent in cooked ham impaired platelet and monocyte activation and the levels of plasmatic P-selectin, MCP-1 and interleukin 6 in healthy subjects. This study strongly suggests the existence of a mechanism that links dietary biopeptides and beneficial health effects.

Platelets and von Willebrand factor in atherogenesis

The role of platelet adhesion, activation, and aggregation in acute atherothrombotic events such as myocardial infarction and stroke is well established. There is increasing evidence that platelet-endothelial interactions also contribute to early atherosclerotic plaque initiation and growth. Through these interactions, platelet-derived factors can contribute to the proinflammatory and mitogenic status of resident mural cells. Among the many putative mechanisms for platelet-endothelial interactions, increased endothelial-associated von Willebrand factor, particularly in a multimerized form, which interacts with platelet glycoproteins and integrins, is a major factor and represents a therapeutic target in early atherogenesis.

An exploratory look at NETosis in atherosclerosis

Current evidence suggests the likelihood of a link between venous thromboembolism (VTE) and atherosclerosis, although they have been traditionally considered as different pathological entities. The contribution of neutrophils to human atherogenesis has been underestimated, if compared to their contribution established in VTE. This is due to the major importance attributed to macrophages in plaque destabilization. Nevertheless, the role of neutrophils in atherogenesis deserves increasing attention. In particular, neutrophil extracellular traps (NETs) are net-like chromatin fibres that are released from dying neutrophils. The death of neutrophils with NETs formation is called NETosis. During activation, neutrophils produce reactive oxygen species (ROS), through the activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. The main function of NETs is trapping and killing pathogens. Nevertheless, NETs formation has been observed in various chronic inflammatory diseases, autoimmune diseases, vasculitis, lung diseases, cancer and VTE. Recent studies suggest that NETs formation might contribute also to atherosclerosis progression. New data report the presence of NETs in the luminal portion of human atherosclerotic vessels and coronary specimens obtained from patients after acute myocardial infarction. Programmed death mechanisms in atherosclerosis such as apoptosis, efferocytosis and also NETosis, share common features and triggers. If defective, they can lead the cells to a switch from programmed death to necrosis, resulting in the release of pro-atherogenic factors, accumulation of cell debris and progression of the disease. This review provides evidence on the emerging role of neutrophils focusing on NETosis and oxidative stress burden in orchestrating common mechanisms in atherosclerosis and thrombosis.

Platelet Count and Mean Platelet Volume at the Time of and After Acute Myocardial Infarction

Platelet count has been shown to be lower and mean platelet volume (MPV) to be higher in acute myocardial infarction (MI). However, it is not known whether these changes persist post-MI or if these measures are able to distinguish between acute thrombotic and non-thrombotic MI. Platelet count and MPV were measured in 80 subjects with acute MI (thrombotic and non-thrombotic) and stable coronary artery disease (CAD) at cardiac catheterization (acute phase) and at >3-month follow-up (quiescent phase). Subjects were stratified using stringent clinical, biochemical, histological, and angiographic criteria. Outcome measures were compared between groups by analysis of variance. Forty-seven subjects met criteria for acute MI with clearly defined thrombotic (n = 22) and non-thrombotic (n = 12) subsets. Fourteen subjects met criteria for stable CAD. No significant difference was observed in platelet count between subjects with acute MI and stable CAD at the acute or quiescent phase. MPV was higher in acute MI (9.18 ± 1.21) compared to stable CAD (8.13 ± 0.66; P = 0.003) at the acute phase but not at the quiescent phase (8.48 ± 0.58 vs 8.94 ± 1.42; P = 0.19). No difference in platelet count or MPV was detected between thrombotic and non-thrombotic subsets at acute or quiescent phases. The power to detect differences in these measures between thrombotic and non-thrombotic subsets was 58%. Higher MPV at the time of acute MI is not observed by 3 months post-MI (quiescent phase). Platelet count and MPV do not differ in subjects with thrombotic versus non-thrombotic MI. Further investigation is warranted to evaluate the utility of these measures in the diagnosis of acute MI.

Factor Xa Signaling Contributes to the Pathogenesis of Inflammatory Diseases

The coagulation protease Factor Xa (FXa) triggers a variety of signaling pathways through activation of protease-activated receptors (PARs) and non-PAR receptors. FXa-mediated signaling is strongly implicated in the pathogenesis of several inflammatory diseases including fibrosis, cardiovascular diseases, and cancer. Thus, targeting of FXa can have great clinical significance in terms of the treatment of these disorders. This review summarizes the current knowledge about the mechanism of FXa signaling in cellular and animal systems under (patho) physiological conditions for a better understanding and hence a better management of FXa-induced disorders. J. Cell. Physiol. 232: 1966-1970, 2017. © 2016 Wiley Periodicals, Inc.

High shear stress induces atherosclerotic vulnerable plaque formation through angiogenesis

Rupture of atherosclerotic plaques causing thrombosis is the main cause of acute coronary syndrome and ischemic strokes. Inhibition of thrombosis is one of the important tasks developing biomedical materials such as intravascular stents and vascular grafts. Shear stress (SS) influences the formation and development of atherosclerosis. The current review focuses on the vulnerable plaques observed in the high shear stress (HSS) regions, which localizes at the proximal region of the plaque intruding into the lumen. The vascular outward remodelling occurs in the HSS region for vascular compensation and that angiogenesis is a critical factor for HSS which induces atherosclerotic vulnerable plaque formation. These results greatly challenge the established belief that low shear stress is important for expansive remodelling, which provides a new perspective for preventing the transition of stable plaques to high-risk atherosclerotic lesions.