The multifaceted contribution of platelets in the emergence and aftermath of acute cardiovascular events

Illustrated Abstracts of the 5th EUPLAN International Conference

These illustrated capsules have been prepared by some speakers of State-of-the-Art talks and of original investigations, presented at the 5th European Platelet Network (EUPLAN) International Conference, which was held at the Università degli Studi di Milano (Italy) on September 28-30, 2022. The programme featured various state-of-the-art lectures and a selection of oral presentations covering a broad range of topics in platelet and megakaryocyte biology, from basic science to recent advances in clinical studies. As usual, the meeting brought together senior scientists and trainees in an informal atmosphere to discuss platelet science in person.

Plasma protein signatures for high on-treatment platelet reactivity to aspirin and clopidogrel in peripheral artery disease

BACKGROUND

A significant proportion of patients with peripheral artery disease (PAD) displays a poor response to aspirin and/or the platelet P2Y12 receptor antagonist clopidogrel. This phenomenon is reflected by high on-treatment platelet reactivity (HTPR) in platelet function assays in vitro and is associated with an increased risk of adverse cardiovascular events.

OBJECTIVE

This study aimed to elucidate specific plasma protein signatures associated with HTPR to aspirin and clopidogrel in PAD patients.

METHODS AND RESULTS

Based on targeted plasma proteomics, 184 proteins from two cardiovascular Olink panels were measured in 105 PAD patients. VerifyNow ASPI- and P2Y12-test values were transformed to a continuous variable representing HTPR as a spectrum instead of cut-off level-defined HTPR. Using the Boruta random forest algorithm, the importance of 3 plasma proteins for HTPR in the aspirin, six in clopidogrel and 10 in the pooled group (clopidogrel or aspirin) was confirmed. Network analysis demonstrated clusters with CD84, SLAMF7, IL1RN and THBD for clopidogrel and with F2R, SELPLG, HAVCR1, THBD, PECAM1, TNFRSF10B, MERTK and ADM for the pooled group. F2R, TNFRSF10B and ADM were higher expressed in Fontaine III patients compared to Fontaine II, suggesting their relation with PAD severity.

CONCLUSIONS

A plasma protein signature, including eight targets involved in proatherogenic dysfunction of blood cell-vasculature interaction, coagulation and cell death, is associated with HTPR (aspirin and/or clopidogrel) in PAD. This may serve as important systems-based determinants of poor platelet responsiveness to aspirin and/or clopidogrel in PAD and other cardiovascular diseases and may contribute to identify novel treatment strategies.

Effect of fibrinolytic therapy on ST-elevation myocardial infarction clinical outcomes during the COVID-19 pandemic: A systematic review and meta-analysis

BACKGROUND

ST-elevation myocardial infarction (STEMI) is the result of transmural ischemia of the myocardium and is associated with a high mortality rate. Primary percutaneous coronary intervention (PPCI) is the recommended first-line treatment strategy for patients with STEMI. The timely delivery of PPCI became extremely challenging for STEMI patients during the coronavirus disease 2019 (COVID-19) pandemic, leading to a projected steep rise in mortality. These delays were overcome by the shift from first-line therapy and the development of modern fibrinolytic-based reperfusion. It is unclear whether fibrinolytic-based reperfusion therapy is effective in improving STEMI endpoints.

AIM

To determine the incidence of fibrinolytic therapy during the COVID-19 pandemic and its effects on STEMI clinical outcomes.

METHODS

PubMed, Google Scholar, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were queried from January 2020 up to February 2022 to identify studies investigating the effect of fibrinolytic therapy on the prognostic outcome of STEMI patients during the pandemic. Primary outcomes were the incidence of fibrinolysis and the risk of all-cause mortality. Data were meta-analyzed using the random effects model to derive odds ratios (OR) and 95% confidence intervals. Quality assessment was carried out using the Newcastle-Ottawa scale.

RESULTS

Fourteen studies including 50136 STEMI patients (n = 15142 in the pandemic arm; n = 34994 in the pre-pandemic arm) were included. The mean age was 61 years; 79% were male, 27% had type 2 diabetes, and 47% were smokers. Compared with the pre-pandemic period, there was a significantly increased overall incidence of fibrinolysis during the pandemic period [OR: 1.80 (1.18 to 2.75); I²= 78%; P = 0.00; GRADE: Very low]. The incidence of fibrinolysis was not associated with the risk of all-cause mortality in any setting. The countries with a low-and middle-income status reported a higher incidence of fibrinolysis [OR: 5.16 (2.18 to 12.22); I² = 81%; P = 0.00; GRADE: Very low] and an increased risk of all-cause mortality in STEMI patients [OR: 1.16 (1.03 to 1.30); I² = 0%; P = 0.01; GRADE: Very low]. Meta-regression analysis showed a positive correlation of hyperlipidemia (P = 0.001) and hypertension (P < 0.001) with all-cause mortality.

CONCLUSION

There is an increased incidence of fibrinolysis during the pandemic period, but it has no effect on the risk of all-cause mortality. The low- and middle-income status has a significant impact on the all-cause mortality rate and the incidence of fibrinolysis.

Treatment of congenital thrombocytopenia and decreased collagen reactivity in G6b-B-deficient mice

Mice lacking the immunoreceptor tyrosine-based inhibition motif-containing co-inhibitory receptor G6b-B (Mpig6b, G6b knockout, KO) are born with a complex megakaryocyte (MK) per platelet phenotype, characterized by severe macrothrombocytopenia, expansion of the MK population, and focal myelofibrosis in the bone marrow and spleen. Platelets are almost completely devoid of the glycoprotein VI (GPVI)-FcRγ-chain collagen receptor complex, have reduced collagen integrin α2β1, elevated Syk tyrosine kinase activity, and a subset has increased surface immunoglobulins. A similar phenotype was recently reported in patients with null and loss-of-function mutations in MPIG6B. To better understand the cause and treatment of this pathology, we used pharmacological- and genetic-based approaches to rescue platelet counts and function in G6b KO mice. Intravenous immunoglobulin resulted in a transient partial recovery of platelet counts, whereas immune deficiency did not affect platelet counts or receptor expression in G6b KO mice. Syk loss-of-function (R41A) rescued macrothrombocytopenia, GPVI and α2β1 expression in G6b KO mice, whereas treatment with the Syk kinase inhibitor BI1002494 partially rescued platelet count but had no effect on GPVI and α2β1 expression or bleeding. The Src family kinase inhibitor dasatinib was not beneficial in G6b KO mice. In contrast, treatment with the thrombopoietin mimetic romiplostim rescued thrombocytopenia, GPVI expression, and platelet reactivity to collagen, suggesting that it may be a promising therapeutic option for patients lacking functional G6b-B. Intriguingly, GPVI and α2β1 expression were significantly downregulated in romiplostim-treated wild-type mice, whereas GPVI was upregulated in romiplostim-treated G6b KO mice, suggesting a cell intrinsic feedback mechanism that autoregulates platelet reactivity depending on physiological needs.

The impact of triglyceride-glucose index on ischemic stroke: a systematic review and meta-analysis

BACKGROUND

Strokes significantly impair quality of life and incur high economic and societal burdens. The triglyceride and glucose (TyG) index is a biochemical marker of insulin resistance (IR) and may have important value in the prediction of strokes, especially ischemic stroke (IS). Our study aims to investigate the relationship between TyG index and IS and ascertain whether TyG index is independently associated with IS adverse outcomes.

METHODS

The Cochrane, Embase, Medline, Web of Science, PubMed, and other relevant English databases and related websites were systematically searched for articles on ''TyG index'' and "stroke" published from inception to April 4, 2022. We reviewed the available literature on the TyG index and its relation to predicting IS occurrence in the general population and adverse clinical outcomes. We calculated odds ratios (OR) of TyG index and its predictability of IS occurrence and adverse outcomes. Statistical analyses were performed using the Meta Package in STATA, version 12.0.

RESULTS

A total of 18 studies and 592,635 patients were included in our analysis. The pooled effect values of all stroke types showed that higher TyG index was associated with increased the risk of IS in the general population (OR 1.37; 95% CI 1.22-1.54) in a total sample of 554,334 cases with a high level of heterogeneity (P = 0.000, I² = 74.10%). In addition, compared to IS patients with a lower TyG index, IS patients with a higher TyG index was associated with higher risk of stroke recurrence (OR: 1.50; 95% CI 1.19-1.89) and increased risk of mortality (OR 1.40 95% CI 1.14-1.71). No correlation was found in the effect value combinations of poor functional outcomes (OR 1.12; 95% CI 0.88-1.43) and neurological worsening (OR: 1.76; 95% CI 0.79-3.95) in a total sample of 38,301 cases with a high level of heterogeneity (P = 0.000; I² = 77.20%).

CONCLUSIONS

TyG index has potential value in optimizing risk stratification for IS in the general population. Furthermore, there is a significant association between high TyG index and many adverse outcomes of stroke, especially stroke recurrence and high mortality. Future studies should focus on multi-center and multi-regional designs in order to further explore the relationship between IS and TyG index.

The Pathogenic Role of Oxidative Stress, Cytokine Expression, and Impaired Hematological Indices in Diabetic Cardiovascular Diseases

A simultaneous increase in the prevalence of diabetes mellitus (DM), a risk factor for cardiovascular diseases (CVDs), has contributed to the escalation of CVD related mortalities. To date, oxidative stress and inflammation are increasingly recognized as significant drivers of cardiovascular complications in patients with diabetes. Therefore, this study aims to explore the correlation between oxidative stress, inflammation, and hematological indices in diabetic patients with CVDs. Patients were allocated into five groups: healthy controls; nondiabetic patients with myocardial infarction; diabetic patients with myocardial infarction; nondiabetic patients with heart failure; and diabetic patients with heart failure. The results revealed that the malondialdehyde levels were increased; whereas superoxide dismutase enzyme activities were markedly reduced in all CVD groups compared with those of healthy controls. Although the mRNA expression levels of interleukin (IL)-6, IL-18, and IL-38 were significantly increased, those of the anti-inflammatory cytokine, IL-35, have been reduced in all CVD groups compared with healthy controls. Regarding hematological indices, hematocrit, red blood cell distribution width, mean platelet (PLT) volume, plateletcrit, PLT distribution width, leukocyte count, and PLT-to-lymphocyte and neutrophil-to-lymphocyte ratios were markedly increased in the diabetic and nondiabetic CVD groups compared with those of the healthy controls. Oxidative stress and cytokine biomarkers may play a significant role in the complications of diabetic cardiomyopathy. Moreover, hematological indices are particularly sensitive to systemic inflammatory changes and are novel markers for the early detection of diabetic cardiomyopathy.

Reticulated Platelets and Their Relationship with Endothelial Progenitor Cells during the Acute Phase of ST-Elevation Myocardial Infarction

Introduction: Endothelial progenitor cells (EPC) and reticulated platelets (RP) have central roles in the thrombotic and angiogenetic interactions during ST-elevation myocardial infarction (STEMI). The EPC and RP response in patients with STEMI treated by primary percutaneous intervention (PPCI) has not yet been investigated. Methods: We assessed EPC quantification by the expression of CD133+ and CD34+, and EPC function by the capacity of the cells to form colony-forming units (CFU) and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) during the acute phase of STEMI. These measurements were correlated with RP at baseline and after 24 h following PPCI. Results: Our cohort included 89 consecutive STEMI-diagnosed patients enrolled between December 2018 and July 2021. At baseline, there was a strong positive correlation between reticulated platelet quantity and MTT levels (R = 0.766 and R2 = 0.586, p < 0.001), CD34+ levels (R = 0.602, and R2 = 0.362, p < 0.001); CD133+ levels (R = 0.666 and R2 = 0.443, p < 0.001) and CFU levels (R = 0.437, R2 = 0.191, p < 0.001). The multiple linear regression showed that levels of MTT (adjusted R2 = 0.793; p < 0.001), CD34+ and CD133+ (adjusted R2 = 0.654; p < 0.001 and adjusted R2 = 0.627; p < 0.001, respectively) had strong independent correlations with RP response. At 24 h after PPCI, the correlation between RP quantity and EPC markers was not significant, except for MTT levels (R = 0.465, R2 = 0.216, p < 0.001). Conclusions: In patients with STEMI, higher levels of RP at baseline are significantly correlated with a more potent EPC response. The translational significance of these findings needs further investigation.

Sex differences at the platelet-vascular interface

Platelets are multifunctional cells that ensure the integrity of the vascular wall and modulate the immune response at the blood/vascular interface. Their pathological activation results in both thrombosis and inflammation and implicates them in the pathogenesis of vascular disease. Vascular diseases are sexually dimorphic in terms of incidence, clinical presentation, outcome, and efficacy of anti-platelet therapy. We here provide an overview of what is known about the role of platelets in the initiation and progression of vascular diseases and summarize what is known about the sex differences in platelet reactivity and in the thromboinflammatory mechanisms that drive these diseases, with a particular focus on atherosclerosis, obstructive and non-obstructive coronary artery disease, and ischemic stroke. Understanding the sex differences at the platelet-vascular interface is clinically relevant as it will enable: (1) to design new therapeutic strategies that prevent the detrimental effects of the immune-modulatory function of platelets taking sex into account, and (2) to evaluate if sex-specific anti-platelet drug regimens should be used to reduce the risk not only of thrombosis but also of vascular disease progression.

Autophagy Ameliorates Reactive Oxygen Species-Induced Platelet Storage Lesions

Platelet transfusion is a life-saving therapy to prevent bleeding; however, the availability of platelets for transfusion is limited by the markedly short shelf life owing to the development of platelet storage lesions (PSLs). The mechanism of PSLs remains obscure. Dissection of the intracellular biological changes in stored platelets may help to reduce PSLs and improve platelet transfusion efficiency. In the present study, we explore the changes of stored platelets at room temperature under constant agitation. We found that platelets during storage showed an increased reactive oxygen species (ROS) generation accompanied with receptor shedding, apoptosis, and diminished platelet aggregation. ROS scavenger reduced platelet shedding but also impaired platelet aggregation. Autophagy is a conserved catabolic process that sequesters protein aggregates and damaged organelles into lysosomes for degradation and platelets’ own intact autophagic system. We revealed that there exist a stable autophagic flux in platelets at the early stage of storage, and the autophagic flux in platelets perished after long-term storage. Treatment stored platelets with rapamycin, which stimulates autophagy in eukaryotic cells, markedly ameliorated PSLs, and improved platelet aggregation in response to extracellular stimuli.

N-Acetylcysteine Inhibits Platelet Function through the Regeneration of the Non-Oxidative Form of Albumin

N-acetylcysteine (NAC) is able to break down protein disulfides, generating free thiols. This mechanism occurs on mixed disulfides of albumin (HSA) to form mercaptoalbumin (HMA), the main antioxidant species in the plasma. Circulating HSA exists in two main forms: the reduced form (HMA), and the oxidized forms, whose predominant modification is cystenylation (HSA-Cys). Increased levels of oxidized HSA have been detected in several diseases associated with oxidative stress. This study showed that NAC inhibits platelet aggregation by restoring HMA. In addition, the regeneration of HMA by NAC inhibits platelet functions such as intracellular calcium mobilization, reactive oxygen species generation, arachidonic acid metabolites synthesis, and adhesion to the collagen matrix. In our conditions, the exposure of platelets to NAC did not increase GSH levels. However, the inhibition of platelet aggregation was also detected following treatment of platelet-rich plasma with GSH, which, similarly to NAC, reduced HSA-Cys levels. Furthermore, this study showed that cysteine, another compound able to restore HMA by reducing the HSA-Cys content, inhibited platelet aggregation to a similar extent as NAC. The results obtained in this study suggest a new mechanism by which NAC can modulate platelet activation and suggest its possible use as an antiplatelet drug in conditions associated with oxidative stress.

Atypical Roles of the Chemokine Receptor ACKR3/CXCR7 in Platelet Pathophysiology

The manifold actions of the pro-inflammatory and regenerative chemokine CXCL12/SDF-1α are executed through the canonical GProteinCoupledReceptor CXCR4, and the non-canonical ACKR3/CXCR7. Platelets express CXCR4, ACKR3/CXCR7, and are a vital source of CXCL12/SDF-1α themselves. In recent years, a regulatory impact of the CXCL12-CXCR4-CXCR7 axis on platelet biogenesis, i.e., megakaryopoiesis, thrombotic and thrombo-inflammatory actions have been revealed through experimental and clinical studies. Platelet surface expression of ACKR3/CXCR7 is significantly enhanced following myocardial infarction (MI) in acute coronary syndrome (ACS) patients, and is also associated with improved functional recovery and prognosis. The therapeutic implications of ACKR3/CXCR7 in myocardial regeneration and improved recovery following an ischemic episode, are well documented. Cardiomyocytes, cardiac-fibroblasts, endothelial lining of the blood vessels perfusing the heart, besides infiltrating platelets and monocytes, all express ACKR3/CXCR7. This review recapitulates ligand induced differential trafficking of platelet CXCR4-ACKR3/CXCR7 affecting their surface availability, and in regulating thrombo-inflammatory platelet functions and survival through CXCR4 or ACKR3/CXCR7. It emphasizes the pro-thrombotic influence of CXCL12/SDF-1α exerted through CXCR4, as opposed to the anti-thrombotic impact of ACKR3/CXCR7. Offering an innovative translational perspective, this review also discusses the advantages and challenges of utilizing ACKR3/CXCR7 as a potential anti-thrombotic strategy in platelet-associated cardiovascular disorders, particularly in coronary artery disease (CAD) patients post-MI.

Synergistic Effects of Natural Product Combinations in Protecting the Endothelium Against Cardiovascular Risk Factors

Endothelial dysfunction is an early hallmark of cardiovascular diseases (CVDs). Monotherapies are limited due to the complex, multifactorial pathways. The multi-component and multi-targeted approach of natural products have the potential to manage CVDs.

This review aims to provide a comprehensive insight into the synergistic mechanism of natural product combinations in protecting the endothelium against various cardiovascular risk factors.

Databases (PubMed, MEDLINE and EMBASE) and Google Scholar were searched, and studies in English published between January 2000 and February 2022 were collated. Clinical and pre-clinical studies of natural product combinations with or without pharmaceutical medicines, compared with monotherapy and/or proposing the underlying mechanism in protecting endothelial function, were included.

Four clinical studies demonstrated that natural product combinations or natural product-pharmaceutical combinations improved endothelial function. This was associated with multi-targeted effects or improved absorption of the active substances in the body. Seventeen preclinical studies showed that natural product combinations produced synergistic (demonstrated by combination index or Bliss independence model) or enhanced effects in protecting the endothelium against hyperlipidemia, hypertension, diabetes mellitus, platelet activation, oxidative stress and hyperhomocysteinemia. The molecular targets included reactive oxygen species, Nrf2-HO-1, p38MAPK, P13K/Akt and NF-κB.

Thus, the current available evidence of natural product combinations in targeting endothelial dysfunction is predominantly from preclinical studies. These have demonstrated synergistic/enhanced pharmacological activities and proposed associated mechanisms. However, evidence from larger, well-designed clinical trials remains weak. More cohesion is required between preclinical and clinical data to support natural product combinations in preventing or slowing the progression of CVDs.

Combined Antiplatelet Therapy Reduces the Proinflammatory Properties of Activated Platelets

The cause of atherothrombosis is rupture or erosion of atherosclerotic lesions, leading to an increased risk of myocardial infarction or stroke. Here, platelet activation plays a major role, leading to the release of bioactive molecules, for example, chemokines and coagulation factors, and to platelet clot formation. Several antiplatelet therapies have been developed for secondary prevention of cardiovascular events, in which anticoagulant drugs are often combined. Besides playing a role in hemostasis, platelets are also involved in inflammation. However, it is unclear whether current antiplatelet therapies also affect platelet immune functions. In this study, the possible anti-inflammatory effects of antiplatelet medications on chemokine release were investigated using enzyme-linked immunosorbent assay and on the chemotaxis of THP-1 cells toward platelet releasates. We found that antiplatelet medication acetylsalicylic acid (ASA) led to reduced chemokine (CC motif) ligand 5 (CCL5) and chemokine (CXC motif) ligand 4 (CXCL4) release from platelets, while leukocyte chemotaxis was not affected. Depending on the agonist, α _IIb β ₃ and P2Y ₁₂ inhibitors also affected CCL5 or CXCL4 release. The combination of ASA with a P2Y ₁₂ inhibitor or a phosphodiesterase (PDE) inhibitor did not lead to an additive reduction in CCL5 or CXCL4 release. Interestingly, these combinations did reduce leukocyte chemotaxis. This study provides evidence that combined therapy of ASA and a P2Y ₁₂ or PDE3 inhibitor can decrease the inflammatory leukocyte recruiting potential of the releasate of activated platelets.

Characterization of Atherosclerotic Plaque Coating for Thrombosis Microfluidics Assays

Introduction

Studying arterial thrombus formation by in vitro flow assays is a widely used approach. Incorporating human atherosclerotic plaque material as a thrombogenic surface in these assays represents a method to model the pathophysiological environment of thrombus formation upon plaque disruption. Up until now, achieving a homogeneous coating of plaque material and subsequent reproducible platelet adhesion has been challenging. Here, we characterized a novel method for coating of plaque material on glass coverslips for use in thrombosis microfluidic assays.

Methods

A homogenate of human atherosclerotic plaques was coated on glass coverslips by conventional manual droplet coating or by spin coating. Prior to coating, a subset of coverslips was plasma treated. Water contact angle measurements were performed as an indicator for the hydrophilicity of the coverslips. Homogeneity of plaque coatings was determined using profilometric analysis and scanning electron microscopy. Thrombogenicity of the plaque material was assessed in real time by microscopic imaging while perfusing whole blood at a shear rate of 1500 s⁻¹ over the plaque material.

Results

Plasma treatment of glass coverslips, prior to spin coating with plaque material, increased the hydrophilicity of the coverslip compared to no plasma treatment. The most homogeneous plaque coating and highest platelet adhesion was obtained upon plasma treatment followed by spin coating of the plaque material. Manual plaque coating on non-plasma treated coverslips yielded lowest coating homogeneity and platelet adhesion and activation.

Conclusion

Spin coating of atherosclerotic plaque material on plasma treated coverslips leads to a more homogenous coating and improved platelet adhesion to the plaque when compared to conventional droplet coating on non-plasma treated coverslips. These properties are beneficial in ensuring the quality and reproducibility of flow experiments.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-021-00713-9.

Inhibition of Phosphodiesterase 3A by Cilostazol Dampens Proinflammatory Platelet Functions

OBJECTIVE

platelets possess not only haemostatic but also inflammatory properties, which combined are thought to play a detrimental role in thromboinflammatory diseases such as acute coronary syndromes and stroke. Phosphodiesterase (PDE) 3 and -5 inhibitors have demonstrated efficacy in secondary prevention of arterial thrombosis, partially mediated by their antiplatelet action. Yet it is unclear whether such inhibitors also affect platelets' inflammatory functions. Here, we aimed to examine the effect of the PDE3A inhibitor cilostazol and the PDE5 inhibitor tadalafil on platelet function in various aspects of thromboinflammation. Approach and results: cilostazol, but not tadalafil, delayed ex vivo platelet-dependent fibrin formation under whole blood flow over type I collagen at 1000 s-1. Similar results were obtained with blood from Pde3a deficient mice, indicating that cilostazol effects are mediated via PDE3A. Interestingly, cilostazol specifically reduced the release of phosphatidylserine-positive extracellular vesicles (EVs) from human platelets while not affecting total EV release. Both cilostazol and tadalafil reduced the interaction of human platelets with inflamed endothelium under arterial flow and the release of the chemokines CCL5 and CXCL4 from platelets. Moreover, cilostazol, but not tadalafil, reduced monocyte recruitment and platelet-monocyte interaction in vitro.

CONCLUSIONS

this study demonstrated yet unrecognised roles for platelet PDE3A and platelet PDE5 in platelet procoagulant and proinflammatory responses.

Vascular protective effect of aspirin and rivaroxaban upon endothelial denudation of the mouse carotid artery

While in recent trials the dual pathway inhibition with aspirin plus rivaroxaban has shown to be efficacious in patients with atherosclerotic cardiovascular disease, little is known about the effects of this combination treatment on thrombus formation and vascular remodelling upon vascular damage. The aim of this study was to examine the effects of aspirin and/or rivaroxaban on injury-induced murine arterial thrombus formation in vivo and in vitro, vessel-wall remodelling, and platelet-leukocyte aggregates. Temporary ligation of the carotid artery of C57BL/6 mice, fed a western type diet, led to endothelial denudation and sub-occlusive thrombus formation. At the site of ligation, the vessel wall stiffened and the intima-media thickened. Aspirin treatment antagonized vascular stiffening and rivaroxaban treatment led to a positive trend towards reduced stiffening. Local intima-media thickening was antagonized by both aspirin or rivaroxaban treatment. Platelet-leukocyte aggregates and the number of platelets per leukocyte were reduced in aspirin and/or rivaroxaban treatment groups. Furthermore, rivaroxaban restricted thrombus growth and height in vitro. In sum, this study shows vascular protective effects of aspirin and rivaroxaban, upon vascular injury of the mouse artery.