Thrombosis: a major contributor to the global disease burden

Phillyrin and its metabolites treat pulmonary embolism by targeting PLCβ3 to inhibit platelet activation

ETHNOPHARMACOLOGICAL RELEVANCE

Lian Qiao (LQ), the dried fruit of Forsythia suspensa (Thunb.) Vahl, is a well-documented traditional Chinese medicine known for its detoxifying and heat-clearing properties. Clinically, compounds containing LQ are widely used to treat thrombotic diseases, indicating that it may have antithrombotic effects. However, its exact mechanism of action remains unknown.

AIM OF THE STUDY

This study aimed to verify the antithrombotic effect of LQ and further explore the material basis and target mechanism of its antithrombotic effect using various biological methods.

MATERIALS AND METHODS

An epinephrine-collagen-thrombin-induced mouse model of acute pulmonary embolism (APE) was established to study the effects of LQ on thrombus development. A UPLC/Q/TOF-MS screening and identification system based on the inhibition of platelet aggregation and Ca2+ antagonism was established to determine the pharmacodynamic components of LQ that inhibit platelet activation. The inhibitory effect of active ingredients on platelet activation, and the determination of the target of their inhibitory effect on platelet activation have been studied using chemical proteomics. Furthermore, based on the structure and function of the target protein, a multidisciplinary approach was adopted to analyze the molecular mechanism of active ingredient binding to target proteins and to evaluate the effects of active ingredients on the downstream signaling pathways of target proteins.

RESULTS

LQ showed significant anticoagulant effects in APE model mice. Phillyrin and phillygenin were the antiplatelet-activating components of LQ. PLCβ3 was identified as a target for inhibiting platelet activation by phillyrin and its metabolites. The mechanism underlying the effect involves phillyrin and its metabolites inhibiting PLCβ3 activity by blocking the binding of PLCβ3 to Gαq through non-covalently targeting the ASN260 of PLCβ3, thus inhibiting the downstream Gαq-PLCβ3-Ca2+ signaling pathway, effectively hindering platelet activation and therefore playing an anticoagulant role.

CONCLUSION

This study not only proposes and validates the antithrombotic effect of LQ for the first time but also finds that phillyrin and phillygenin are the main pharmacological substances through which LQ exerts antithrombotic activity and reveals a novel mechanism by which they exert antiplatelet activity by directly targeting and inhibiting PLCβ3 activity. These findings significantly contribute to our understanding of the therapeutic potential of phillyrin and provide important clues for the discovery and development of new antiplatelet drugs.

Overview of the chemistry and biological activities of natural atisine-type diterpenoid alkaloids

Atisine-type C20-diterpenoid alkaloids (DAs) are a very important class of diterpenoid alkaloids, which play an important role in the biosynthesis of DAs. To date, 87 atisine-type DAs and 11 bis-DAs containing an atisine unit have been reported from five genera in two families. The genus Spiraea in Rosaceae family could be regarded as the richest resource for atisine-type DAs, followed by the genera Delphinium and Aconitum in the Ranunculaceae family. Among the reported atisine-type DAs, several possess unprecedented skeletons. Natural atisine-type DAs have a wide range of biological activities, including antitumor, antiplatelet aggregation, biological control, and anti-inflammatory, analgesic, antiarrhythmic, and cholinesterase inhibitory effects, which are closely related to their structures. In particular, the antiparasitic effect of atisine-type DAs is more prominent than that of other types of DAs, which highlights their potential in antiparasite drug discovery. In summary, the high chemical and biological diversity of atisine-type DAs indicates their great potential as a vast resource for drug discovery.

Discovery of Heparin Mimetic, Potent, and Selective Inhibitors of Human Clotting Factor XIIIa

Factor XIIIa (FXIIIa) is a cysteine transglutaminase that catalyzes the last step in the coagulation process. An anion-binding site inhibition of FXIIIa is a paradigm-shifting strategy that may offer key advantages of controlled inhibition. Such an approach is likely to lead to novel FXIIIa inhibitors that do not carry bleeding risks. We previously reported a flavonoid trimer-based allosteric inhibitor of FXIIIa with moderate potency and selectivity. To further advance this approach, we evaluated a series of 27 variably sulfonated heparin mimetics against human FXIIIa. Only 13 molecules exhibited inhibitory activity at the highest concentration tested with IC50 values of 2-286 μM. Specifically, inhibitor 16 demonstrated an IC50 value of 2.4 ± 0.5 μM in a bisubstrate, fluorescence-based trans-glutamination assay. It also demonstrated a significant selectivity over other clotting factors including thrombin, factor Xa, and factor XIa as well as other cysteine enzymes including papain and tissue transglutaminase 2. Inhibitor 16 did not affect the viability of three human cell lines at a concentration that is 5-fold its FXIIIa-IC50. The molecule had a very weak effect on the activated partial thromboplastin time of human plasma at a concentration of >700 μM, further supporting its functional selectivity. Importantly, molecule 16 inhibited FXIIIa-mediated polymerization of fibrin(ogen) in a concentration-dependent manner as shown by the gel electrophoresis experiment. Michaelis-Menten kinetics revealed that the molecule competes with the Gln-donor protein substrate, i.e., dimethylcasein, but not with the Lys-donor small substrate, i.e., dansylcadaverine. Molecular modeling studies revealed that this type of molecule likely binds to an anion-binding site comprising the basic amino acids of Lys54, Lys61, Lys73, Lys156, and Arg244 among others. Overall, our work puts forward a new anion-binding site, selective, nontoxic, sulfonated heparin mimetic FXIIIa inhibitor 16 for further development as an effective and safer anticoagulant.

Diagnostic value of D-dimer to fibrinogen ratio for pulmonary embolism in postpartum women

BACKGROUND

Pulmonary embolism is a common disease associated with high mortality and morbidity. Diagnosing pulmonary embolism is challenging due to diverse clinical presentations and the lack of specific biomarkers. The study aimed to investigate the diagnostic value on pulmonary embolism for postpartum women by D-dimer to fibrinogen ratio, and it combined with neutrophil-to-lymphocyte ratio or platelet-to-lymphocyte ratio.

METHODS

A total of 537 women with suspected pulmonary embolism were selected as the research subjects from the Shanghai First Maternity and Infant Hospital between 1 January 2019 and 31 October 2022. The D-dimer to fibrinogen ratio and it combined with neutrophil-to-lymphocyte ratio or platelet-to-lymphocyte ratio were applied to evaluate the clinical probability of pulmonary embolism, and the positive predictive value of both scores were calculated using computed tomography pulmonary arteriography as a gold standard. The diagnostic value of D-dimer to fibrinogen ratio, combined with neutrophil-to-lymphocyte ratio or platelet-to-lymphocyte ratio was evaluated by the area under the curve, sensitivity, specificity, and other indicators in the receiver operator characteristic curve.

RESULTS

Among the 502 women included for analysis, 194 (38.65%) were definitely diagnosed as pulmonary embolism. The positive predictive values of D-dimer to fibrinogen ratio and it combined with platelet-to-lymphocyte ratio or neutrophil-to-lymphocyte ratio were 70.1%, 50.5%, and 56.5%, respectively in the postpartum women, the area under the curve for the D-dimer to fibrinogen ratio and it combined with platelet-to-lymphocyte ratio or neutrophil-to-lymphocyte ratio were 0.606 (95%CI: 0.562-0.650), 0.624 (95%CI: 0.575-0.673), and 0.639 (95%CI: 0.592-0.686), respectively. The negative predictive values of D-dimer to fibrinogen ratio, it combined with platelet-to-lymphocyte ratio or neutrophil-to-lymphocyte ratio were 50.5%, 70.1%, and 69.8%, respectively.

CONCLUSION

The diagnostic value of the D-dimer to fibrinogen ratio was higher than the D-dimer for the postpartum women with suspected pulmonary embolism. The combination of either the neutrophil-to-lymphocyte ratio or the platelet-to-lymphocyte ratio with D-dimer to fibrinogen ratio is an appropriate strategy to rule out pulmonary embolism.

Venous thromboembolism prophylaxis usage among surgical patients in both private and public hospitals in Ethiopia

Background

Venous thromboembolism (VTE) remains the commonest preventable cause of death in postoperative patients. VTE prophylaxis significantly reduces mortality risk, yet its utilization remains alarmingly low and variable (6-61 %) worldwide. This study aimed to compare VTE prophylaxis use among adult surgical patients in major hospitals in Addis Ababa, Ethiopia.

Materials and methods

A multicenter cross-sectional study was conducted in one private (Myungsung Christian Medical Center Comprehensive Specialized Hospital (MCM CSH)), and two public hospitals (Yekatit 12 Hospital Medical College and Menelik II Referral Hospital). Data was collected by chart review using standardized checklist. Caprini score was used for risk stratification, and associations was assessed using chi-square test with significance set at p < 0.05.

Results

From a total of 423 patients, 222 (52.3 %) patients were male. The mean age of the patients is 43.3(±14.7 SD) years. 414 (98 %) patients were at risk for VTE with 257(61 %) having moderate to high risk, but only 31(7.5 %) were on prophylaxis. Prophylaxis use was 12.5 % in MCM CSH, but it was 5.5 % and 5.1 % in Yekatit 12 and Menelik II Referral Hospitals respectively. VTE prophylaxis use was significantly less in public hospitals (p < 0.05).

Conclusions

Despite the majority of surgical patients being at risk of developing VTE, VTE prophylaxis remains significantly underutilized across major private and public hospitals in Ethiopia, particularly in public settings. The current study suggests standard risk assessment model implementation to address this significant and understudied risk to patients' lives.

Impact of Cirrhosis Etiology on the Risk for Venous Thromboembolism

BACKGROUND

Cirrhosis is associated with an increased risk for both bleeding and venous thromboembolic (VTE) complications. The data regarding the impact of etiology of cirrhosis on VTE risk is poorly understood.

METHODS

In this retrospective observational analysis of the US Nationwide readmissions database 2019, we identified hospitalized patients who had cirrhosis from alcohol, viral, or nonalcoholic steatohepatitis (NASH) etiologies. We identified patients who had acute VTE, chronic/history of VTE, and portal venous thrombosis (PVT). Overall VTE risk was defined as the composite of acute and chronic VTE or PVT. The impact of etiology of cirrhosis on the crude and risk adjusted rates of VTE and PVT was studied.

RESULTS

Of 432,383 patients with cirrhosis, 41.4% patients had NASH-cirrhosis, 39.7% had alcohol-related cirrhosis, and 18.9% had viral cirrhosis. The overall VTE rate was highest in patients with NASH cirrhosis (10.8%) followed by viral cirrhosis (9.7%) and alcohol-related cirrhosis (7.5%; P < 0.001). Similar results were observed for acute and chronic VTE. After risk adjustment, patients with NASH (OR 1.48 95% CI 1.42-1.54) and viral cirrhosis (OR 1.22 95% CI 1.17-1.29) had significantly higher overall VTE risk compared with alcohol-related cirrhosis. When separately evaluated, the adjusted risk for acute and chronic VTE was similar between patients with alcohol-related and viral cirrhosis but higher with NASH cirrhosis. PVT rate was highest with viral cirrhosis (4.3%) followed by NASH (2.8%) and alcohol-related cirrhosis (2.4%; P < 0.001). The adjusted risk of PVT was higher with viral (OR 1.61 95% CI 1.50-1.72) and NASH cirrhosis (OR 1.41 95% CI 1.31-1.52).

CONCLUSION

NASH cirrhosis was associated with a higher VTE risk compared with alcohol-related and viral etiologies. As NASH cirrhosis increases in prevalence as the major etiology of cirrhosis, it is important to understand the increased VTE risk associated with this condition to improve management strategies and patient outcomes.

Unmet needs and barriers in venous thromboembolism education and awareness among people living with cancer: a global survey

BACKGROUND

Venous thromboembolism (VTE) is a major preventable cause of morbidity, disability, and mortality in subjects with cancer. A global appraisal of cancer-associated VTE education and awareness is not available.

OBJECTIVES

To evaluate VTE-related education, awareness, and unmet needs from the perspective of people living with cancer using a quantitative and qualitative approach.

METHODS

This cross-sectional study used data from an online-based survey covering multidimensional domains of cancer-associated VTE. Data are presented descriptively. Potential differences across participant subgroups were explored.

RESULTS

Among 2262 patients with cancer from 42 countries worldwide, 55.3% received no VTE education throughout their cancer journey, and an additional 8.2% received education at the time of VTE diagnosis only, leading to 63.5% receiving no or inappropriately delayed education. When education was delivered, only 67.8% received instructions to seek medical attention in case of VTE suspicion, and 36.9% reported scarce understanding. One-third of participants (32.4%) felt psychologically distressed when becoming aware of the potential risks and implications connected with cancer-associated VTE. Most responders (78.8%) deemed VTE awareness highly relevant, but almost half expressed concerns about the quality of education received. While overall consistent, findings in selected survey domains appeared to numerically differ across age group, ethnicity, continent of residence, educational level, metastatic status, and VTE history.

CONCLUSION

This study involving a large and diverse population of individuals living with cancer identifies important unmet needs in VTE-related education, awareness, and support across healthcare systems globally. These findings unveil multilevel opportunities to expedite patient-centered care in cancer-associated VTE prevention and management.

Sodium/Potassium ATPase Alpha 1 Subunit Fine-tunes Platelet GPCR Signaling Function and is Essential for Thrombosis

Background

Thrombosis is a major cause of myocardial infarction and ischemic stroke. The sodium/potassium ATPase (NKA), comprising α and β subunits, is crucial in maintaining intracellular sodium and potassium gradients. However, the role of NKA in platelet function and thrombosis remains unclear.

Methods

We utilized wild-type (WT, α1+/+) and NKA α1 heterozygous (α1+/-) mice, aged 8 to 16 weeks, of both sexes. An intravital microscopy-based, FeCl3-induced carotid artery injury thrombosis model was employed for in vivo thrombosis assessment. Platelet transfusion assays were used to evaluate platelet NKA α1 function on thrombosis. Human platelets isolated from healthy donors and heart failure patients treated with/without digoxin were used for platelet function and signaling assay. Complementary molecular approaches were used for mechanistic studies.

Results

NKA α1 haplodeficiency significantly reduced its expression on platelets without affecting sodium homeostasis. It significantly inhibited 7.5% FeCl3-induced thrombosis in male but not female mice without disturbing hemostasis. Transfusion of α1+/-, but not α1+/+, platelets to thrombocytopenic WT mice substantially prolonged thrombosis. Treating WT mice with low-dose ouabain or marinobufagenin, both binding NKA α1 and inhibiting its ion-transporting function, markedly inhibited thrombosis in vivo. NKA α1 formed complexes with leucine-glycine-leucine (LGL)-containing platelet receptors, including P2Y12, PAR4, and thromboxane A2 receptor. This binding was significantly attenuated by LGL>SFT mutation or LGL peptide. Haplodeficiency of NKA α1 in mice or ouabain treatment of human platelets notably inhibited ADP-induced platelet aggregation. While not affecting 10% FeCl3-induced thrombosis, NKA α1 haplodeficiency significantly prolonged thrombosis time in mice treated with an ineffective dose of clopidogrel.

Conclusion

NKA α1 plays an essential role in enhancing platelet activation through binding to LGL-containing platelet GPCRs. NKA α1 haplodeficiency or inhibition with low-dose ouabain and marinobufagenin significantly inhibited thrombosis and sensitized clopidogrel's anti-thrombotic effect. Targeting NKA α1 emerges as a promising antiplatelet and antithrombotic therapeutic strategy.

Reducing the risk of atherosclerotic cardiovascular disease in people with hemophilia: the importance of primary prevention

Revolutionary advances in the treatment of hemophilia has led to a significant improvement in life expectancy. Associated with this has been an increase in age-related diseases especially atherosclerotic cardiovascular disease (CVD). While people with hemophilia (PWH) develop atherosclerosis at rates similar to those of the general population, rates of atherothrombosis and mortality related to CVD have been much lower, due to their hypocoagulable state. Changing treatment paradigms, aimed at reducing the risk of bleeding by improving hemostasis to levels approaching normality, has meant that the protection they are thought to have had may be lost. CVD risk factors are just as common in PWH as in the general population, but appear to be undertreated. In particular, primary prevention of CVD is vital in all individuals, but particularly in PWH as treatment of established CVD can be difficult. Active identification and management of CVD risk factors, such as obesity, physical inactivity, hypertension, and hypercholesterolemia, is required. In particular, statins have been shown to significantly reduce cardiovascular and all-cause mortality with few adverse events and no increased risk of bleeding in the general population, and their use needs urgent assessment in PWH. Further longitudinal research into preventing CVD in PWH, including accurate CVD risk assessment, is required to optimize prevention and management.

Circulating Cytokines and Venous Thromboembolism: A Bidirectional Two-Sample Mendelian Randomization Study

BACKGROUND

 Epidemiological evidence has linked circulating cytokines to venous thromboembolism (VTE). However, it remains uncertain whether these associations are causal due to confounding factors or reverse causality. We aim to explore the causality between circulating cytokines and VTE, encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

 In the current bidirectional Mendelian randomization (MR) study, instrumental variables of 41 circulating cytokines were obtained from the genome-wide association study meta-analyses (8,293 individuals). Summary statistics for the association of VTE (17,048 cases and 325,451 controls), DVT (8,077 cases and 295,014 controls), and PE (8,170 cases and 333,487 controls) were extracted from the FinnGen Study. A multivariable MR study was conducted to adjust for potential confounders. The inverse-variance weighted method was employed as the main analysis, and comprehensive sensitivity analyses were conducted in the supplementary analyses.

RESULTS

 The MR analysis indicated stromal cell-derived factor-1α was suggestively associated with a reduced risk of VTE (odds ratio [OR]: 0.90; 95% confidence interval [CI]: 0.81-0.99; p = 0.033) and DVT (OR: 0.85; 95% CI: 0.75-0.97; p = 0.015). In addition, suggestive association of granulocyte colony-stimulating factor with PE (OR: 1.20; 95% CI: 1.06-1.37; p = 0.005) was observed. Multivariable MR analysis showed that the effect of cytokines on VTE was partly mediated through hemoglobin A1c and systolic blood pressure. Reverse MR analysis revealed that VTE was linked to decreased levels of several cytokines.

CONCLUSION

 We provide suggestive genetic evidence supporting the bidirectional causal effect between circulating cytokines and VTE, highlighting the importance of targeting circulating cytokines to reduce the incidence of VTE.

Venous thromboembolism risk is lower in patients with atopic dermatitis than other immune-mediated inflammatory diseases: A retrospective, observational, comparative cohort study using US claims data

BACKGROUND

Certain immune-mediated inflammatory diseases (IMIDs) may increase patients' risk for venous thromboembolisms (VTEs), yet how atopic dermatitis (AD) influences VTE risk remains unclear.

OBJECTIVE

Describe VTE incidence in patients with AD compared with other IMIDs and unaffected, AD-matched controls.

METHODS

This retrospective, observational, comparative cohort study used Optum Clinformatics United States claims data (2010-2019) of adults with AD, rheumatoid arthritis (RA), Crohn's disease (CD), ulcerative colitis (UC), psoriasis (PsO), psoriatic arthritis (PsA), or ankylosing spondylitis (AS). Unaffected control patients were matched 1:1 with patients with AD.

RESULTS

Of 2,061,222 patients with IMIDs, 1,098,633 had AD. Patients with AD had a higher VTE incidence (95% CI) than did unaffected, AD-matched controls (0.73 [0.72-0.74] versus 0.59 [0.58-0.60] cases/100 person-years). When controlling for baseline VTE risk factors, however, AD was not associated with increased VTE risk (HR 0.96 [0.90-1.02]). VTE risk was lower in patients with AD versus RA, UC, CD, AS, or PsA; VTE risk was similar to patients with PsO.

LIMITATIONS

Disease activity and severity were not accounted for.

CONCLUSION

AD did not increase VTE risk when accounting for underlying risk factors. AD was associated with lower VTE risk compared with several rheumatologic and gastrointestinal IMIDs.

Integrating network pharmacology with microRNA microarray analysis to identify the role of miRNAs in thrombosis treated by the Dahuang Zhechong pill

BACKGROUND

Thrombotic diseases are the leading causes of death worldwide, urging for improvements in treatment strategies. Dahuang Zhechong pill (DHZCP) is a traditional Chinese medicine widely used for treating thrombotic diseases; however, the underlying mechanisms remain unclear. This study aimed to explore the potential mechanisms of DHZCP in treating thrombosis with a focus on bioinformatics and miRNAs.

METHODS

We used network pharmacology to explore the targets of thrombosis treated with DHZCP and performed microarray analysis to acquire miRNA profiles and predict the target genes in thrombin-stimulated MEG-01 cells treated with DHZCP. Based on the overlapping of targets, we carried out a component-target-miRNA network and enrichment analysis and validated the selected miRNAs and mRNAs using quantitative reverse transcription-polymerase chain reaction.

RESULTS

Our data showed 850 targets of 230 active ingredients of DHZCP and 1214 thrombosis-related genes; 235 targets were common. We identified 32 miRNAs that were regulated by thrombin stimulation but regulated reversely by DHZCP treatment in MEG-01 cells, and predicted 1846 targets with function annotation. We analyzed conjointly 23 integrating targets from network pharmacology and microarray. HIF1A, PIK3CA, MAPK1 and BCL2L1 emerged as key nodes in the network diagrams. We confirmed the differential expression of seven miRNAs, one mRNA (BCL2L1) and platelet surface protein.

CONCLUSIONS

This study showed that miRNAs and their targets, such as BCL2L1, played crucial roles in platelet activation during DHZCP intervention in thrombosis, highlighting their potential to alleviate platelet activation and increase cell apoptosis. The study's findings could help develop new strategies for improving thrombosis treatment.

RNA methylation patterns, immune characteristics, and autophagy-related mechanisms mediated by N6-methyladenosine (m6A) regulatory factors in venous thromboembolism

Recent studies have found a link between deep vein thrombosis and inflammatory reactions. N6-methyladenosine (m6A), a crucial element in immunological regulation, is believed to contribute to the pathophysiology of venous thromboembolism (VTE). However, how the m6A-modified immune microenvironment is involved in VTE remains unclear. In the present study, we identified a relationship between VTE and the expression of several m6A regulatory elements by analyzing peripheral blood samples from 177 patients with VTE and 88 healthy controls from public GEO databases GSE19151 and GSE48000. We used machine learning to identify essential genes and constructed a diagnostic model for VTE using multivariate logistic regression. Unsupervised cluster analysis revealed a marked difference between m6A modification patterns in terms of immune cell infiltration, inflammatory reactivity, and autophagy. We identified two m6A-related autophagy genes (i.e., CHMP2B and SIRT1) and the crucial m6A regulator YTHDF3 using bioinformatics. We also examined two potential mechanisms through which YTHDF3 may affect VTE. m6A modification, immunity, and autophagy are closely linked in VTE, offering novel mechanistic and therapeutic insights.

Therapeutic implication of MicroRNA-320a antagonist in attenuating blood clots formed during venous thrombosis

Venous thrombosis (VT) is a complex multi-factorial disease and a major health concern worldwide. Its clinical implications include deep vein thrombosis (DVT) and pulmonary embolism (PE). VT pathogenesis involves intricate interplay of various coagulants and anti-coagulants. Growing evidences from epidemiological studies have shown that many non-coding microRNAs play significant regulatory role in VT pathogenesis by modulating expressions of large number of gene involved in blood coagulation. Present study aimed to investigate the effect of human micro RNA (hsa-miR)-320a antagonist on thrombus formation in VT. Surgery was performed on Sprague-Dawley (SD) rats, wherein the inferior vena cava (IVC) was ligated to introduce DVT. Animals were divided into four groups (n = 5 in each group); Sham controls (Sham), IVC ligated-DVT (DVT), IVC ligated-DVT + transfection reagent (DVT-NC) and IVC ligated-DVT + miR320a antagonist (DVT-miR-320a antagonist). IVC was dissected after 6 h and 24 h of surgery to estimate thrombus weight and coagulatory parameters such as levels of D-dimer, clotting time and bleeding time. Also, ELISA based biochemical assays were formed to assess toxicity of miRNA antagonist in animals. Our experimental analysis demonstrated that there was a marked reduction in size of thrombus in hsa-miR-320a antagonist treated animals, both at 6 h and 24 h. There was a marked reduction in D-dimer levels in hsa-miR-320a antagonist treated animals. Also, blood clotting time was delayed and bleeding time was increased significantly in hsa-miR-320a antagonist treated rats compared to the non-treated and Sham rats. There was no sign of toxicity in treated group compared to control animals. Hsa-miR-320a antagonist could be promising therapeutic target for management of VT.

Evaluation of venous thromboembolism risk assessment models for hospital inpatients: the VTEAM evidence synthesis

Background

Pharmacological prophylaxis during hospital admission can reduce the risk of acquired blood clots (venous thromboembolism) but may cause complications, such as bleeding. Using a risk assessment model to predict the risk of blood clots could facilitate selection of patients for prophylaxis and optimise the balance of benefits, risks and costs.

Objectives

We aimed to identify validated risk assessment models and estimate their prognostic accuracy, evaluate the cost-effectiveness of different strategies for selecting hospitalised patients for prophylaxis, assess the feasibility of using efficient research methods and estimate key parameters for future research.

Design

We undertook a systematic review, decision-analytic modelling and observational cohort study conducted in accordance with Enhancing the QUAlity and Transparency Of health Research (EQUATOR) guidelines.

Setting

NHS hospitals, with primary data collection at four sites.

Participants

Medical and surgical hospital inpatients, excluding paediatric, critical care and pregnancy-related admissions.

Interventions

Prophylaxis for all patients, none and according to selected risk assessment models.

Main outcome measures

Model accuracy for predicting blood clots, lifetime costs and quality-adjusted life-years associated with alternative strategies, accuracy of efficient methods for identifying key outcomes and proportion of inpatients recommended prophylaxis using different models.

Results

We identified 24 validated risk assessment models, but low-quality heterogeneous data suggested weak accuracy for prediction of blood clots and generally high risk of bias in all studies. Decision-analytic modelling showed that pharmacological prophylaxis for all eligible is generally more cost-effective than model-based strategies for both medical and surgical inpatients, when valuing a quality-adjusted life-year at £20,000. The findings were more sensitive to uncertainties in the surgical population; strategies using risk assessment models were more cost-effective if the model was assumed to have a very high sensitivity, or the long-term risks of post-thrombotic complications were lower. Efficient methods using routine data did not accurately identify blood clots or bleeding events and several pre-specified feasibility criteria were not met. Theoretical prophylaxis rates across an inpatient cohort based on existing risk assessment models ranged from 13% to 91%.

Limitations

Existing studies may underestimate the accuracy of risk assessment models, leading to underestimation of their cost-effectiveness. The cost-effectiveness findings do not apply to patients with an increased risk of bleeding. Mechanical thromboprophylaxis options were excluded from the modelling. Primary data collection was predominately retrospective, risking case ascertainment bias.

Conclusions

Thromboprophylaxis for all patients appears to be generally more cost-effective than using a risk assessment model, in hospitalised patients at low risk of bleeding. To be cost-effective, any risk assessment model would need to be highly sensitive. Current evidence on risk assessment models is at high risk of bias and our findings should be interpreted in this context. We were unable to demonstrate the feasibility of using efficient methods to accurately detect relevant outcomes for future research.

Future work

Further research should evaluate routine prophylaxis strategies for all eligible hospitalised patients. Models that could accurately identify individuals at very low risk of blood clots (who could discontinue prophylaxis) warrant further evaluation.

Study registration

This study is registered as PROSPERO CRD42020165778 and Researchregistry5216.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR127454) and will be published in full in Health Technology Assessment; Vol. 28, No. 20. See the NIHR Funding and Awards website for further award information.

Abbott D-dimer assay: analytical performance and diagnostic accuracy in management of venous thromboembolism

This study aimed to assess analytical characteristics and diagnostic accuracy in management of venous thromboembolism (VTE) in the Emergency Department (ED) of the Abbott D-dimer assay applied on the Alinity c clinical chemistry analyzer (Abbott Laboratories, Chicago, IL) compared to the INNOVANCE D-dimer assay (Siemens Healthineers, Marburg, Germany). Precision was determined at three concentration levels following the CLSI EP15-A3 protocol. Method comparison and diagnostic accuracy were assessed using samples obtained from 85 patients who were referred for diagnostic imaging and D-dimer testing due to clinically suspected VTE. Within-run coefficients of variation (CVs) were 3.0%, 0.5% and 0.5% at D-dimer concentrations of 0.54, 1.42 and 2.68 mg/L FEU, while respective between-run CVs were 2.0%, 3.4% and 2.7%, hence fulfilling the desirable biological variation criteria for imprecision (<12.6%). Passing-Bablok regression analysis yielded a small proportional difference between the two compared assays (y = 1.09 (95% confidence interval (CI): 1.01-1.18) x + 0.09 (95%CI: -0.09 to 0.16)), while Bland-Altman analysis showed significant negative absolute (-0.6 mg/L FEU, 95%CI: -0.9 to -0.3) and relative mean bias (-14.1%, 95%CI: -20.3 to -7.9). Spearman's ρ was 0.979 (95%CI: 0.967-0.986). Inter-assay agreement relative to the cut-off was 92% (kappa coefficient = 0.547 (95%CI: 0.255-0.839)). Diagnostic sensitivity, specificity, positive and negative predictive values of the Abbott assay were 100%, 9.2%, 25.3% and 100%, respectively, compared to the following data for the INNOVANCE assay: 95.0%, 15.4%, 25.7% and 90.9%. Abbott D-dimer assay has shown excellent analytical precision, high comparability with the INNOVANCE D-dimer and high NPV at manufacturer's cut-off.

Design a dual-response two-photon fluorescent probe for simultaneous imaging of mitochondrial viscosity and peroxynitrite in a thrombosis model

BACKGROUND

Venous thromboembolism is a sudden cardiovascular disease that can lead to death, and its pathologic development is closely related to vascular viscosity and inflammation. However, direct evidence from in vivo is really scarce. The key limitation is that the combined probes cannot detect multiple markers simultaneously, which may lead to unreliable results. Therefore, to develop a single probe that can simultaneously monitor the variations of viscosity in the vascular microenvironment as well as inflammation level during venous thrombosis.

RESULTS

A dual-responsive two-photon fluorescent probe, Cou-ONOO, was designed and synthesized. Cou-ONOO provides a visualization tool for monitoring the viscosity of the vascular as well as the inflammatory marker ONOO‾ during thromboembolism via dual-channel simultaneous imaging. As a single probe that can recognize dual targets, Cou-ONOO effectively avoids the problems from unreliable results caused by complex synthesis and differences in intracellular localization, diffusion, and metabolism of different dyes as using combinatorial probes. Using Cou-ONOO, simultaneous imaging the variations of viscosity and ONOO‾at the cellular and tissue levels was successfully performed. In addition, Cou-ONOO also successfully visualized and tracked the viscosity of the vascular microenvironment and ONOO‾ during venous embolism in mice.

SIGNIFICANCE

Experimental results show that both viscosity and inflammation are abnormally overexpressed in the microenvironment at the thrombus site during venous thrombosis. An intuitive visualization tool to elucidate the variations of viscosity as well as inflammation level in the vascular microenvironment during thrombosis was provided, which will facilitate a better clinical understanding of the pathological process of thrombosis.

Aptamer-thrombin loaded magnetic microspheres for bio-specific extraction and precise detection of hirudin

Hirudin, that is naturally occurring in leeches (Hirudo medicinalis) and known as the most potent natural inhibitor of thrombin, exerts double-edged effects in clinic application. It can be used as a therapeutic ingredient for cardiovascular disease, while it can be regarded as a toxic polypeptide with bleeding risk. Effective detection of hirudin in biological samples contributes greatly to reasonable therapy. In this study, we proposed a smart adsorbent based on affinity magnetic microspheres, where thrombin was immobilized for capturing hirudin in the animal serum. Aptamer was introduced as a ligand for linking the magnetic agarose microspheres and thrombin, thereby avoiding loss of biological activity of the enzyme to hirudin. Taken recombinant hirudin variant 2-Lys47 (rHV2) as a model, we established a rapid and bio-specific extraction method coupled with liquid chromatography and quadrupole-time-of-flight mass spectrometry (LC-QTOF/MS) for determination of hirudin in the serum. Owing to this strategy, a low limit of detection (LOD) of rHV2 (0.5 nM), a good linearity with correlation coefficient of 0.9975, an acceptable precision with relative standard deviation (RSD) below 3.6% (n = 6) and acceptable recoveries ranging from 85.7% to 90.2% were achieved. Moreover, the functionalized magnetic composite could be reused for at least nine cycles. Our work combined the merits of affinity separation and advanced instrument analysis for hirudin, providing a new vision to precise determination of hirudin in medical and pharmaceutical fields.

Retrospective cross-sectional analysis of concurrent VTE diagnosis in hospitalised socially excluded individuals in Ireland

OBJECTIVE

Social exclusion (such as that experienced by people who are homeless, incarcerated or use drugs) increases morbidity across a range of diseases but is poorly captured in routine data sets. The aim of this study was to use a novel composite variable in a national-level hospital usage dataset to identify social exclusion and to determine whether social exclusion is associated with concurrent venous thromboembolism (VTE) in hospitalised patients in Ireland. Identifying and characterising this association in people who are socially excluded will inform VTE prevention and treatment strategies.

DESIGN

Retrospective cross-sectional study.

SETTING

Irish Hospital Inpatient Enquiry (HIPE) system, which collects diagnostic information by International Classification of Diseases Tenth Revision code on all hospital admission episodes in the Ireland.

PARTICIPANTS

All hospital admission episodes involving a VTE diagnosis (in a primary 'Dx 1' or secondary 'Dx 2-30' coding position) during a 12-month period in the Ireland were identified from consolidated, national-level datasets derived from the Irish HIPE system. Social exclusion was defined as the presence of one or more indicators of homelessness, drug use, incarceration, health hazards due to socioeconomic status or episodes of healthcare terminated prematurely.

RESULTS

Of 5701 admission episodes involving a VTE diagnosis (in a primary or secondary position) during the study period, 271 (4.8%) related to an individual affected by social exclusion. Among hospitalised individuals identified as being socially excluded based on the novel composite variable, the likelihood of having a concurrent VTE diagnosis was over twofold greater than that observed in the general population (OR 2.14, 95% CI 1.79 to 2.26; p<0.001).

CONCLUSION

These data suggest that VTE (primary and secondary) is over-represented in hospitalised socially excluded persons in Ireland and that the development of strategies to address this potentially life-threatening accompanying condition in this vulnerable patient group must be prioritised.

Availability of medical and endovascular therapies for venous thromboembolism: a global survey for World Thrombosis Day

BACKGROUND

Data on availability, affordability, and accessibility is key for the planning of global strategies to reduce the burden of venous thromboembolism (VTE).

OBJECTIVES

A survey was conducted for the 10th anniversary of World Thrombosis Day to assess the availability of VTE therapies worldwide and challenges in uniform implementation.

METHODS

We gathered information on the approval status, availability, utilization, occurrence of shortages, and spread of medical and interventional therapies for VTE. Furthermore, we collected information by accessing or contacting national or continental medicines agencies, manufacturers or distributors, and online drug repositories.

RESULTS

We obtained data from a total of 69 countries: 33 countries in Europe, 19 in Asia, 7 in the Americas, 9 in Africa, and 1 in Oceania. Unfractionated heparin, low-molecular-weight heparin, and vitamin K antagonists were available in almost all countries, but shortages were recorded in 13%, 19%, and 15% of them, respectively. Direct oral anticoagulants were available in approximately three-quarters of the surveyed countries. At least one parenteral medication for heparin-induced thrombocytopenia was available in 57% of countries and a shortage was reported in 9% of these. Shortage of thrombolytics was recorded in 50% of countries. Overall, at least one type of catheter-directed therapy system was approved for use in 77% of countries and available in 23% of surveyed institutions. Our findings revealed notable geographic disparities in the worldwide availability of VTE therapies, the access to which appeared to be limited by economic and geopolitical factors.

CONCLUSION

We anticipate that this comprehensive information will play a pivotal role in highlighting the shortcomings of VTE therapies and the lack of homogeneous availability globally.

Assessing the impact of a financial incentive and refill reminder program on medication adherence and costs

BACKGROUND

Improving medication adherence remains an important goal to improve therapeutic outcomes and lower health care costs. Point-of-sale prescription costs and forgetfulness remain top reasons why patients do not adhere to medications. Programs using both text message-based reminders and financial incentives may encourage patients to refill their prescriptions on time by reducing copays through discounts at the point of sale. Sempre Health, the subject of our analysis, provides both text message refill reminders and a dynamic discount incentive program to improve medication adherence.

OBJECTIVE

To evaluate the impact of a financial incentive/refill reminder program on medication adherence and total cost of care for patients taking the antithrombotic agents ticagrelor, apixaban, or rivaroxaban in a large regional health plan.

METHODS

After propensity-score matching on demographics, socioeconomic status, baseline copay, prior pharmacy/medical spend, and morbidity, we compared-using a difference-in-differences analytic approach-adherence (measured by proportion of days covered), unplanned health care utilization, and costs (total cost of care, medical, and pharmacy cost) of health plan members who did and did not enroll in the financial incentive/refill reminder program between February 1, 2019, and October 31, 2021, over 1 and 2 years. Because of differences in patient characteristics, we analyzed patients on ticagrelor (the antiplatelet group), apixaban, and rivaroxaban (the anticoagulant group) separately.

RESULTS

There were a total of 1,292 one-to-one program and control propensity-matched patients: 166 each for the antiplatelet group and 480 each for the anticoagulant group. The average age of the anticoagulant group was 62 years; more than 60% were male, and approximately 45% had no prior unplanned care events. In contrast, the average age of the antiplatelet group was 57 years; more than 70% were male, and approximately 21% had no prior unplanned care events. In the antiplatelet group, the proportions adherent (proportion of days covered ≥80%) were 63.3% vs 42.8% (P = 0.0002) for program vs controls. Similarly, in the anticoagulant group, the proportion adherent was 77.9% vs 60.2% (P < 0.0001) for program vs controls. Reflecting improved adherence, costs of apixaban and rivaroxaban increased by $79 per member per month (PMPM) (P < 0.0001), with no statistically significant differences in other costs. Similarly, the cost of ticagrelor increased by $77 PMPM (P = 0.0102) with no statistically significant differences in other costs. Finally, there was a 16% (P = 0.032) reduction in emergency department use for those in the program.

CONCLUSIONS

The financial incentive and refill reminder program was associated with improved adherence to antithrombotic medications, reduced emergency department use, and increased medication costs, but not in total pharmacy, medical, or total cost of care in both subgroups.

Determination of vWF, ADAMTS-13 and Thrombospondin-1 in Venous Thromboembolism and Relating Them to the Presence of Factor V Leiden Mutation

Thrombophilia in venous thromboembolism (VTE) is multifactorial. Von Willebrand factor (vWF) plays a major role in primary hemostasis. While elevated vWF levels are well documented in VTE, findings related to its cleaving protease (ADAMTS-13) are contradicting. The aim of this study was to determine vWF, ADAMTS-13, and the multifactorial Thrombospondin-1 (TSP-1) protein levels in patients after 3-6 months following an unprovoked VTE episode. We also explored a possible association with factor V Leiden (FVL) mutation. vWF, ADAMTS-13 and TSP-1 were analyzed using ELISA kits in 60 VTE patients and 60 controls. Patients had higher levels of vWF antigen (P = .021), vWF collagen-binding activity (P = .008), and TSP-1 protein (P < .001) compared to controls. ADAMTS-13 antigen was lower in patients (P = .046) compared to controls but ADAMTS-13 activity was comparable between the two groups (P = .172). TSP-1 showed positive correlation with vWF antigen (rho = 0.303, P = .021) and negative correlation with ADAMTS-13 activity (rho = -0.244, P = .033) and ADAMTS-13 activity/vWF antigen ratio (rho = -0.348, P = .007). A significant association was found between the presence of FVL mutation and VTE (odds ratio (OR): 9.672 (95% confidence interval (CI) 2.074-45.091- P = .004), but no association was found between the mutation and the studied proteins (P > .05). There appears to be an imbalance between vWF and ADAMTS-13 in VTE patients even after 3-6 months following the onset of VTE. We report that the odds of developing VTE in carriers of FVL mutation are 9.672 times those without the mutation, but the presence of this mutation is not associated with the studied proteins.

No evidence for a genetic causal effect of breast cancer on venous thromboembolism: a mendelian randomization study

Active cancer is known to contribute to venous thromboembolism (VTE), but the cause-and-effect association of breast cancer on VTE is not yet clear. In order to investigate the possible causal relationships, we used a Mendelian randomization analysis. Data for generically predicted breast cancer were identified based on the BCAC consortium. A meta-analysis of genome-wide association study (GWAS) comprising 1,500,861 participants for VTE as well as data from the FinnGen study for VTE, DVT and PE was used for the causal-effect estimation. Our primary method was inverse-variance weighted (IVW), and our supplementary methods included weighted median and MR-Egger. We also carried out sensitivity analysis for the study. No evidence of causal-effect was detected of overall breast cancer on VTE in both the GWAS meta-analysis (OR=1.01, 95%CI:0.98-1.04, p = 0.495) and the FinnGen consortium (OR=1.00,95%CI:0.96-1.04, p = 0.945). In addition, the presence of ER-positive or ER-negative disease did not significantly influence the incidence of VTE and its subtypes. In conclusion, no genetic cause-and-effect of breast cancer on VTE risk was detected in the large MR analysis.

Foldable low-cost point-of-care device for testing blood coagulation using smartphones

Cardiovascular diseases (CVDs) caused by thrombotic events are a significant global health concern, affecting millions of people worldwide. The international normalized ratio (INR) is the most widely used measure of coagulation status, and frequent testing is required to adjust blood-thinning drug dosage, requiring hospital visits and experts to perform the test. Here we present a low-cost and portable smartphone-based device for screening INR levels from whole blood samples at the point of care. Our device uses a 3D printed platform and light-emitting diode backlight modules to create a uniform optical environment, and its foldable design allows for easy transport. Our device also features an algorithm that allows users to acquire and process video of sample flow in a microfluidic channel on their smartphone, providing a cost-effective and convenient option for blood coagulation monitoring at the point of care. We tested the performance of our smartphone-based INR device using both commercially available control samples and clinical human blood samples, demonstrating high accuracy and reliability. Our device has the potential to improve patient outcomes by enabling more frequent monitoring and, as appropriate, dosage adjustments of blood-thinning drugs, providing an affordable and portable option for screening INR levels at the point of care.

Artificial intelligence in the prediction of venous thromboembolism: A systematic review and pooled analysis

BACKGROUND

Accurate diagnostic and prognostic predictions of venous thromboembolism (VTE) are crucial for VTE management. Artificial intelligence (AI) enables autonomous identification of the most predictive patterns from large complex data. Although evidence regarding its performance in VTE prediction is emerging, a comprehensive analysis of performance is lacking.

AIMS

To systematically review the performance of AI in the diagnosis and prediction of VTE and compare it to clinical risk assessment models (RAMs) or logistic regression models.

METHODS

A systematic literature search was performed using PubMed, MEDLINE, EMBASE, and Web of Science from inception to April 20, 2021. Search terms included "artificial intelligence" and "venous thromboembolism." Eligible criteria were original studies evaluating AI in the prediction of VTE in adults and reporting one of the following outcomes: sensitivity, specificity, positive predictive value, negative predictive value, or area under receiver operating curve (AUC). Risks of bias were assessed using the PROBAST tool. Unpaired t-test was performed to compare the mean AUC from AI versus conventional methods (RAMs or logistic regression models).

RESULTS

A total of 20 studies were included. Number of participants ranged from 31 to 111 888. The AI-based models included artificial neural network (six studies), support vector machines (four studies), Bayesian methods (one study), super learner ensemble (one study), genetic programming (one study), unspecified machine learning models (two studies), and multiple machine learning models (five studies). Twelve studies (60%) had both training and testing cohorts. Among 14 studies (70%) where AUCs were reported, the mean AUC for AI versus conventional methods were 0.79 (95% CI: 0.74-0.85) versus 0.61 (95% CI: 0.54-0.68), respectively (p < .001). However, the good to excellent discriminative performance of AI methods is unlikely to be replicated when used in clinical practice, because most studies had high risk of bias due to missing data handling and outcome determination.

CONCLUSION

The use of AI appears to improve the accuracy of diagnostic and prognostic prediction of VTE over conventional risk models; however, there was a high risk of bias observed across studies. Future studies should focus on transparent reporting, external validation, and clinical application of these models.

Extracellular vesicles in venous thromboembolism and pulmonary hypertension

Venous thromboembolism (VTE) is a multifactorial disease, and pulmonary hypertension (PH) is a serious condition characterized by pulmonary vascular remodeling leading with increased pulmonary vascular resistance, ultimately leading to right heart failure and death. Although VTE and PH have distinct primary etiologies, they share some pathophysiologic similarities such as dysfunctional vasculature and thrombosis. In both conditions there is solid evidence that EVs derived from a variety of cell types including platelets, monocytes, endothelial cells and smooth muscle cells contribute to vascular endothelial dysfunction, inflammation, thrombosis, cellular activation and communications. However, the roles and importance of EVs substantially differ between studies depending on experimental conditions and parent cell origins of EVs that modify the nature of their cargo. Numerous studies have confirmed that EVs contribute to the pathophysiology of VTE and PH and increased levels of various EVs in relation with the severity of VTE and PH, confirming its potential pathophysiological role and its utility as a biomarker of disease severity and as potential therapeutic targets.

Validation of the Pulmonary Embolism Severity Index Risk Classification and the 2019 European Society of Cardiology Risk Stratification in the Southeast Asian Population with Acute Pulmonary Embolism

AIM

To date, no studies representing the Southeast Asian population have validated the Pulmonary Embolism Severity Index (PESI) and 2019 European Society of Cardiology (ESC) risk stratification. Therefore, this study aimed to validate the PESI score, simplified PESI (sPESI), PESI risk classification, and 2019 ESC risk stratification in Southeast Asian patients with acute pulmonary embolism (APE).

METHODS

The present study is a 10-year cross-sectional study. Here, risk regressions were conducted to identify the PESI risk classification, sPESI, and 2019 ESC risk stratification as predictors for 30-day all-cause and PE-related mortalities. Receiver operating characteristic (ROC) curves were constructed to determine the diagnostic ability of the PESI score, sPESI score, PESI risk classification, and 2019 ESC risk stratification to predict 30-day mortality.

RESULTS

A total of 696 patients (male, 286; female, 410; mean age, 57.7±15.7 years) were included in this study from 2011 to 2020. The risk of 30-day all-cause mortality progressively increased with the 2019 ESC risk stratification, being approximately 6-fold higher in the high-risk than in the low-risk class [risk ratio: 6.24 (95% confidence interval (CI), 3.12, 12.47), P＜0.001]. The risk of 30-day all-cause mortality with the PESI risk classification also increased with the risk classes, being approximately 6-fold higher in class V than in class I [adjusted risk ratio: 5.91 (95% CI, 2.25, 15.51), P＜0.001]. The highest area under the receiver operating characteristic curve (AuROC) of the predictive model was the PESI score [AuROC=0.733 (95% CI, 0.685, 0.782)].

CONCLUSION

Our study represents a good validation of the PESI and 2019 ESC risk stratification to predict 30-day mortality after APE diagnosis in the Southeast Asian population.

Platelet proteo-transcriptomic profiling validates mediators of thrombosis and proteostasis in patients with myeloproliferative neoplasms

Patients with chronic Myeloproliferative Neoplasms (MPN) including polycythemia vera (PV) and essential thrombocythemia (ET) exhibit unique clinical features, such as a tendency toward thrombosis and hemorrhage, and risk of disease progression to secondary bone marrow fibrosis and/or acute leukemia. Although an increase in blood cell lineage counts (quantitative features) contribute to these morbid sequelae, the significant qualitative abnormalities of myeloid cells that contribute to vascular risk are not well understood. Here, we address this critical knowledge gap via a comprehensive and untargeted profiling of the platelet proteome in a large (n= 140) cohort of patients (from two independent sites) with an established diagnosis of PV and ET (and complement prior work on the MPN platelet transcriptome from a third site). We discover distinct MPN platelet protein expression and confirm key molecular impairments associated with proteostasis and thrombosis mechanisms of potential relevance to MPN pathology. Specifically, we validate expression of high-priority candidate markers from the platelet transcriptome at the platelet proteome (e.g., calreticulin (CALR), Fc gamma receptor (FcγRIIA) and galectin-1 (LGALS1) pointing to their likely significance in the proinflammatory, prothrombotic and profibrotic phenotypes in patients with MPN. Together, our proteo-transcriptomic study identifies the peripherally-derived platelet molecular profile as a potential window into MPN pathophysiology and demonstrates the value of integrative multi-omic approaches in gaining a better understanding of the complex molecular dynamics of disease.

Regulation of mitochondrial function by hydroquinone derivatives as prevention of platelet activation

Platelet activation plays an essential role in the pathogenesis of thrombotic events in different diseases (e.g., cancer, type 2 diabetes, Alzheimer's, and cardiovascular diseases, and even in patients diagnosed with coronavirus disease 2019). Therefore, antiplatelet therapy is essential to reduce thrombus formation. However, the utility of current antiplatelet drugs is limited. Therefore, identifying novel antiplatelet compounds is very important in developing new drugs. In this context, the involvement of mitochondrial function as an efficient energy source required for platelet activation is currently accepted; however, its contribution as an antiplatelet target still has little been exploited. Regarding this, the intramolecular hydrogen bonding of hydroquinone derivatives has been described as a structural motif that allows the reach of small molecules at mitochondria, which can exert antiplatelet activity, among others. In this review, we describe the role of mitochondrial function in platelet activation and how hydroquinone derivatives exert antiplatelet activity through mitochondrial regulation.

Biomarkers and the post-thrombotic syndrome: A systematic review of biomarkers associated with the occurrence of the post-thrombotic syndrome after lower extremity deep venous thrombosis

INTRODUCTION

Post-thrombotic syndrome (PTS) is a frequent chronic complication of deep venous thrombosis (DVT). Biomarkers are potentially valuable clinical tools for handling PTS. The purpose of this review was to examine which biomarkers are associated with the development of PTS in adults with lower extremity DVT.

METHODS

We performed a systematic review of all English language prospective studies of biomarkers and PTS published in PubMed and EMBASE. Studies were included if diagnosing DVT by diagnostic imaging and assessing PTS by clinical scales, for example, the Villalta scale. Biomarkers of thrombophilia and pathological clot properties were not assessed. Data was reported qualitatively.

RESULTS

15 prospective studies were included. Studies varied widely in study design and methods of data analysis. Forty-six different biomarkers were examined, with seven being measured in two or more studies. The most frequently studied biomarkers were D-dimer, CRP, and IL-6. Associations between PTS and D-dimer were predominantly significant, while results on CRP and IL-6 were inconsistent. ICAM-1 was consistently associated with PTS in all studies and at all timepoints. IL-10 was significantly related to PTS development in the largest study and at all time points. Adiponectin, tPA, HRG and TAFI, MMP-1 and -8, and TIMP-1 and -2 were significantly associated with PTS in single studies.

CONCLUSION

(1) Further research on biomarkers and PTS is clearly warranted. (2) Significant differences in study designs made it difficult to draw reliable conclusions regarding individual biomarkers. We suggest the implementation of a standardized framework for the study of biomarkers and PTS, to make comparison of future studies more feasible. (3) D-dimer, ICAM-1, IL-10, MMP-1 and 8, TIMP-1, TIMP-2, and adiponectin are clinical biomarkers of particular interest to include in future studies of PTS. Large scale systemic quantitative proteomic analyses of DVT patients could help identify novel biomarkers of interest in PTS-patients.

Association of nonalcoholic fatty liver disease and venous thromboembolic disease in healthy adults in Korea: a nationwide study

Nonalcoholic fatty liver disease (NAFLD) can lead to a prothrombotic state, which significantly burdens public healthcare systems. This study investigated the relationship between NAFLD and the incidence of venous thromboembolism (VTE) in Korea using National Health Insurance Service-National Sample Cohort 2.0 data. A population-based retrospective cohort analysis was conducted on 472,212 healthy individuals who underwent national health check-ups in Korea from 2009 to 2014. NAFLD was defined using the fatty liver index (FLI). Multivariate Cox proportional hazards regression models were used to analyze the association between FLI and VTE. Individuals were categorized into four quartiles according to FLI values (first quartile [Q1], 0-5.7; second quartile [Q2], 5.8-15.3; third quartile [Q3], 15.4-37.2; and fourth quartile [Q4], > 37.2). The incidence of VTE tended to increase with increasing FLI values (Q1, 598 [0.5%]; Q2, 1,033 [0.9%]; Q3, 1,443 [1.2%]; and Q4, 1,425 [1.2%]). In the age- and sex-adjusted multivariate model, the hazard ratio (HR) (95% confidence interval [CI]) was 1.47 (1.33‒1.62) for Q4 compared with Q1. After adjusting for clinical variables with P < 0.1 in the univariate analyses, the HR (95% CI) was 1.45 (1.30‒1.62) for Q4 compared with Q1. FLI was related to VTE risk, as confirmed after adjusting for other risk factors.

Prognostication of Patients with Pulmonary Thromboembolism with and without Residual Deep Vein Thrombosis: A Subanalysis of the J'xactly Study

Objectives: It is unclear whether patients with acute pulmonary thromboembolism (PE) with and without residual deep vein thrombosis (DVT) have different prognoses, and there is debate over whether inferior vena cava filters (IVCFs) should be used in conjunction with oral anticoagulants in patients with venous thromboembolism (VTE). Materials and Methods: The J'xactly involved 1,016 patients and was a multicenter, prospective, observational research. In this subanalysis, 419 patients with PE with or without residual DVT who received rivaroxaban with or without IVCFs between February 2016 and April 2018 in Japan were examined. Results: Of 419 patients with PE, 320 had residual DVT. There was no difference between the groups with and without DVT in terms of the percentage of patients who experienced symptomatic PE recurrence (2.8% [9/320] vs. 3.0% [3/99]) or who died from VTE-related complications (0.9% [3/320] vs. 1.0% [1/99]). The percentages of patients with symptomatic PE recurrence were 0% and 3.2%, and the percentages of patients who died from VTE-related causes were 0% and 1.1%, respectively, in the groups with (n=39) and without (n=281) IVCF, albeit not being statistically different. Conclusion: Patients with PE with and without residual DVT did not have a different incidence of symptomatic PE recurrence. These results require additional study to be confirmed.

Stroke vs. Preeclampsia: Dangerous Liaisons of Hypertension and Pregnancy

Stroke during pregnancy and preeclampsia are two distinct but interrelated medical conditions, sharing a common denominator-blood control failure. Along with cardiovascular diseases, diabetes, dyslipidemia, and hypercoagulability, hypertension is undoubtedly a major risk factor associated with stroke. Even though men have higher age-specific stroke rates, women are facing higher life-long stroke risk, primarily due to longer life expectancy. Sex hormones, especially estrogen and testosterone, seem to play a key link in the chain of blood pressure control differences between the genders. Women affected with stroke are more susceptible to experience some atypical stroke manifestations, which might eventually lead to delayed diagnosis establishment, and result in higher morbidity and mortality rates in the population of women. Preeclampsia is a part of hypertensive disorder of pregnancy spectrum, and it is common knowledge that women with a positive history of preeclampsia are at increased stroke risk during their lifetime. Preeclampsia and stroke display similar pathophysiological patterns, including hypertension, endothelial dysfunction, dyslipidemia, hypercoagulability, and cerebral vasomotor reactivity abnormalities. High-risk pregnancies carrying the burden of hypertensive disorder of pregnancy have up to a six-fold higher chance of suffering from stroke. Resemblance shared between placental and cerebral vascular changes, adaptations, and sophisticated auto-regulatory mechanisms are not merely coincidental, but they reflect distinctive and complex cardiovascular performances occurring in the maternal circulatory system during pregnancy. Placental and cerebral malperfusion appears to be in the midline of both of these conditions; placental malperfusion eventually leads to preeclampsia, and cerebral to stoke. Suboptimal performances of the cardiovascular system are proposed as a primary cause of uteroplacental malperfusion. Placental dysfunction is therefore designated as a secondary condition, initiated by the primary disturbances of the cardiovascular system, rather than an immunological disorder associated with abnormal trophoblast invasion. In most cases, with properly and timely applied measures of prevention, stroke is predictable, and preeclampsia is a controllable condition. Understanding the differences between preeclampsia and stroke in pregnancy is vital for healthcare providers to enhance their clinical decision-making strategies, improve patient care, and promote positive maternal and pregnancy outcomes. Management approaches for preeclampsia and stroke require a multidisciplinary approach involving obstetricians, neurologists, and other healthcare professionals.

Caprini risk assessment model combined with D-dimer to predict the occurrence of deep vein thrombosis and guide intervention after laparoscopic radical resection of colorectal cancer

BACKGROUND

To explore the diagnostic value of Caprini risk assessment model (2005) combined with D-dimer for deep vein thrombosis, and to exclude patients with low incidence of thrombosis who might not need anticoagulation after surgery.

METHODS

A total of 171 colorectal cancer patients who underwent surgery from January 2022 to August 2022 were enrolled in this study. Caprini risk assessment model was used to evaluate patients the day before surgery, and full-length venous ultrasonography of lower extremity was used to assess whether patients had thrombosis one day before surgery and the sixth day after surgery. The value of D-dimer was measured by enzyme-linked immunosorbent assays on the first day after surgery, and clinical data of patients were collected during hospitalization.

RESULTS

A total of 171 patients were divided into IPC Group and IPC + LMWH Group according to whether low molecular weight heparin (LMWH) were used to prevent thrombus after surgery. Eventually, 17.6% (15/85) patients in IPC Group and 7% (6/86) patients in IPC + LMWH Group developed DVT. Through separate analysis of IPC Group, it is found that Caprini score and D-dimer were independent risk factors for DVT (Caprini OR 3.39 [95% CI 1.38-8.32]; P = 0.008, D-Dimer OR 6.142 [95% CI 1.209-31.187]; P = 0.029). The area under ROC curve of Caprini risk assessment model is 0.792 (95% CI 0.69-0.945, P < 0.01), the cut-off value is 9.5, and the area under ROC curve of D-dimer is 0.738 (95%CI 0.555-0.921, P < 0.01), the cut-off value is 0.835 μg/mL, and the area under the ROC curve was 0.865 (95% CI 0.754-0.976, P < 0.01) when both of them were combined. Based on decision curve analysis, it is found that Caprini risk assessment model combined with D-dimer can benefit patients more. All patients are divided into four groups. When Caprini score < 10 and D-dimer < 0.835 μg/mL, only 1.23% (1/81) of patients have thrombosis and LMWH has little significance. When Caprini score > 10 and D-dimer > 0.835 μg/mL, the incidence of DVT is 38.7% (12/31) and LMWH should be considered.

CONCLUSIONS

The Caprini risk assessment model and D-dimer can provide more accurate risk stratification for patients after laparoscopic radical resection of colorectal cancer.

A combination of strongly associated prothrombotic single nucleotide polymorphisms could efficiently predict venous thrombosis risk

Background

Venous thrombosis (VT) is multifactorial trait that contributes to the global burden of cardiovascular diseases. Although abundant single nucleotide polymorphisms (SNPs) provoke the susceptibility of an individual to VT, research has found that the five most strongly associated SNPs, namely, rs6025 (F5 Leiden), rs2066865 (FGG), rs2036914 (F11), rs8176719 (ABO), and rs1799963 (F2), play the greatest role. Association and risk prediction models are rarely established by using merely the five strongly associated SNPs. This study aims to explore the combined VT risk predictability of the five SNPs and well-known non-genetic VT risk factors such as aging and obesity in the Hungarian population.

Methods

SNPs were genotyped in the VT group (n = 298) and control group (n = 400). Associations were established using standard genetic models. Genetic risk scores (GRS) [unweighted GRS (unGRS), weighted GRS (wGRS)] were also computed. Correspondingly, the areas under the receiver operating characteristic curves (AUCs) for genetic and non-genetic risk factors were estimated to explore their VT risk predictability in the study population.

Results

rs6025 was the most prevalent VT risk allele in the Hungarian population. Its risk allele frequency was 3.52-fold higher in the VT group than that in the control group [adjusted odds ratio (AOR) = 3.52, 95% CI: 2.50-4.95]. Using all genetic models, we found that rs6025 and rs2036914 remained significantly associated with VT risk after multiple correction testing was performed. However, rs8176719 remained statistically significant only in the multiplicative (AOR = 1.33, 95% CI: 1.07-1.64) and genotypic models (AOR = 1.77, 95% CI: 1.14-2.73). In addition, rs2066865 lost its significant association with VT risk after multiple correction testing was performed. Conversely, the prothrombin mutation (rs1799963) did not show any significant association. The AUC of Leiden mutation (rs6025) showed better discriminative accuracy than that of other SNPs (AUC = 0.62, 95% CI: 0.57-0.66). The wGRS was a better predictor for VT than the unGRS (AUC = 0.67 vs. 0.65). Furthermore, combining genetic and non-genetic VT risk factors significantly increased the AUC to 0.89 with statistically significant differences (Z = 3.924, p < 0.0001).

Conclusions

Our study revealed that the five strongly associated SNPs combined with non-genetic factors could efficiently predict individual VT risk susceptibility. The combined model was the best predictor of VT risk, so stratifying high-risk individuals based on their genetic profiling and well-known non-modifiable VT risk factors was important for the effective and efficient utilization of VT risk preventive and control measures. Furthermore, we urged further study that compares the VT risk predictability in the Hungarian population using the formerly discovered VT SNPs with the novel strongly associated VT SNPs.

Sodium-glucose cotransporter 2 inhibitors and the risk of venous thromboembolism: A population-based cohort study

AIMS

The cardiovascular benefits of sodium-glucose cotransporter 2 inhibitors (SGLT2Is) result from their complex impact on coronary and arterial vessels. However, their effect on veins and the risk of venous thromboembolism (VTE) remains unclear. Meta-analysis of trials has suggested no significant change in risk, but observational studies on the topic are scarce. Our objective was to determine if the use of SGLT2Is, compared to the use of dipeptidyl peptidase 4 inhibitors (DPP-4Is), is associated with the risk of VTE among patients with type 2 diabetes.

METHODS

Using the Clinical Practice Research Datalink linked to hospitalization and vital statistics databases, we conducted a retrospective cohort study using a prevalent new-user design. SGLT2Is were matched to DPP-4I users on calendar time, diabetes treatment intensity, duration of previous DPP-4I use and time-conditional high-dimensional propensity score. Cox proportional hazard models estimated the hazard ratio (HR) for VTE with SGLT2Is versus DPP-4Is.

RESULTS

SGLT2I use was not associated with an increased risk of VTE (HR 0.65, 95% confidence interval [CI] 0.34 to 1.25). This finding was consistent among prevalent (HR 0.47, 95% CI 0.16 to 1.42) and incident (HR 0.75, 95% CI 0.33 to 1.72) new users.

CONCLUSIONS

We found that SGLT2Is were not associated with an increased risk of VTE compared to DPP-4Is. Although we observed a numerically decreased risk of VTE with SGLT2Is, estimates were accompanied by wide 95% CIs. Nonetheless, given the morbidity associated with VTE, our results provide some reassurance regarding the safety of SGLT2Is with respect to VTE.

Ophthalmic nurses' knowledge, attitude, and practice toward venous thromboembolic prevention: a dual-center cross-sectional survey

Background

Venous thromboembolism (VTE) is a severe preventable complication among ophthalmic surgical patients. The knowledge, attitude, and practice (KAP) of nurses play a key role in effective VTE prevention. However, little is known about the KAP of ophthalmic nurses' VTE prevention. This study aimed to examine the level of KAP toward VTE prevention among Chinese ophthalmic nurses and to investigate the influencing factors of their VTE practice.

Methods

A total of 610 ophthalmic nurses from 17 cities in Hunan and Zhejiang Provinces, China, participated in this study. Data was collected via the Sojump online platform from March to April 2021. A self-administered VTE questionnaire was developed to assess nurses' KAP toward VTE prevention. Multiple linear regression analysis was used to analyze the influencing factors of ophthalmic nurses' VTE prevention practice.

Results

The scores (correct rates) of ophthalmic nurses' knowledge, attitude, and practice were 103.87 ± 20.50 (76.4%), 21.96 ± 2.72, and 48.96 ± 11.23 (81.6%), respectively. The three lowest-scored knowledge items were related to VTE complications, physical prevention, and risk assessment. The three lowest-scored attitude items were related to nurses' training, VTE risk, and patient education. The three lowest-scored practice items were related to the assessment scale, VTE assessment, and patient education. Nurses' knowledge, attitude, and practice were significantly correlated with each other. Multiple linear regression analysis showed that Hunan Province (B = 2.77, p = 0.006), general hospital (B = 2.97, p = 0.009), outpatient department (B = 3.93, p = 0.021), inpatient department (B = 2.50, p = 0.001), previous VTE prevention training (B = 3.46, p < 0.001), VTE prevention management in hospital (B = 4.93, p < 0.001), better knowledge (B = 0.04, p = 0.038), and positive attitude towards VTE prevention (B = 1.35, p < 0.001) were all significantly and positively associated with higher practice scores in VTE prevention.

Conclusions

Our study provided a comprehensive understanding of the ophthalmic nurses' knowledge, attitude, and practice in VTE prevention, as well as identified specific items in each dimension for improvement. In addition, our study showed multiple factors were associated with ophthalmic nurses' practice in VTE prevention, including environmental factors, training and management, knowledge and attitudes toward VTE prevention. Our findings provide important implications and guidance for future intervention programs to improve the ophthalmic nurses' knowledge, attitude, and practice in VTE prevention.

Rivaroxaban treatment for asymptomatic venous thromboembolism: insights from the J'xactly study

BACKGROUND

An established treatment strategy for asymptomatic pulmonary embolism (PE) or deep vein thrombosis (DVT) remains uncertain in Japan; therefore, in this study, we clarify the characteristics and outcomes of symptomatic compared to asymptomatic patients with PE or DVT.

METHODS

This prospective, multicenter sub-analysis of the J'xactly study in Japan included 1,016 patients (mean age, 68; 41% male) with venous thromboembolism (VTE) treated with rivaroxaban.

RESULTS

Asymptomatic PE patients (47% of PE patients) were more likely to have active cancer and asymptomatic proximal DVT at lower severity than symptomatic PE patients, despite no differences in age, sex, or the proportion receiving intensive 30 mg/day-rivaroxaban. Patients with asymptomatic DVT (34% of DVT patients) were older, had higher rates of female sex, active cancer, and distal DVT, and received shorter, less intense rivaroxaban treatment. Incidences did not differ between asymptomatic and symptomatic PE patients for recurrent symptomatic VTE (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.22-1.62; P = 0.31) or major bleeding (HR, 0.68; 95% CI, 0.20-2.33; P = 0.58), nor between asymptomatic and symptomatic DVT patients for recurrent symptomatic VTE (HR, 0.56; 95% CI, 0.23-1.40; P = 0.21) and major bleeding (HR, 1.47; 95% CI, 0.54-3.97; P = 0.45).

CONCLUSIONS

The real-world composite adverse event rate for treatment with rivaroxaban, as physician-adjusted for dose and duration, was similar for asymptomatic and symptomatic patients regardless of the presence of PE or DVT, suggesting a favorable safety profile for potential rivaroxaban treatment for asymptomatic VTE.

Re-evaluation of the risk of venous thromboembolism after COVID-19 vaccination using haematological criteria

An elevated risk of venous thromboembolism (VTE) following a first dose of the ChAdOx1 adenovirus-vectored vaccine was found in a national epidemiological study in England using routine discharge diagnosis codes. Separately, the syndrome of vaccine-induced immune thrombotic thrombocytopenia (VITT) was identified using haematological criteria based on presence of thrombocytopenia, significantly elevated D-dimers and development of anti-PF4 antibodies. To re-evaluate risk estimates using haematological criteria, we obtained the haematology results for hospital admitted patients aged 18-64 years in 43 National Health Service trusts in England who were included in the national epidemiological study. Diagnoses were confirmed and haematological parameters obtained from local records without knowledge of vaccination status. The haematological parameters in patients admitted for a confirmed VTE following ChAdOx1 or BNT162b2 mRNA vaccination were then compared with those in a randomly selected 40% sample of unvaccinated patients with VTE. Overall, 12 (14%) of the 84 vaccinated cases had a diagnosis compatible with VITT, 11 after a first dose of ChAdOx1 and one after a first dose of BNT162b2. Thrombocytopenia (platelet count <150 × 109/L) occurred in 17 vaccinated (20%) and 4 (4%) of 108 unvaccinated patients, with all 6 cases of severe thrombocytopenia (<50 × 109/L) occurring within 42 days of a first dose of ChAdOx1. The attributable risk estimates for a cerebral venous thrombosis (CVT) or other VTE with thrombocytopenia after a first dose of ChAdOx1 vaccine were 2.82 and 9.62 per million doses respectively. However, elevated risks were also found after a first dose of ChAdOx1 for VTE without thrombocytopenia with relative incidences for CVT and other VTE of 2.67 (1.77-3.77) and 1.93 (1.57-2.35) respectively. While we identified a distinct population with features of VITT within 42 days of receiving ChAdOx1 vaccination, confirming current diagnostic criteria, we also found evidence of an increased risk of a VTE without thrombocytopenia after ChAdOx1 vaccine.

Application of IPSET-thrombosis in 1366 Patients Prospectively Followed From the Spanish Registry of Essential Thrombocythemia

The International Prognostic Score of thrombosis in Essential Thrombocythemia (IPSET-thrombosis) and its revised version have been proposed to guide thrombosis prevention strategies. We evaluated both classifications to prognosticate thrombosis in 1366 contemporary essential thrombocythemia (ET) patients prospectively followed from the Spanish Registry of ET. The cumulative incidence of thrombosis at 10 years, taking death as a competing risk, was 11.4%. The risk of thrombosis was significantly higher in the high-risk IPSET-thrombosis and high-risk revised IPSET-thrombosis, but no differences were observed among the lower risk categories. Patients allocated in high-risk IPSET-thrombosis (subdistribution hazard ratios [SHR], 3.7 [95% confidence interval, CI, 1.6-8.7]) and high-risk revised IPSET-thrombosis (SHR, 3.2 [95% CI, 1.4-7.45]) showed an increased risk of arterial thrombosis, whereas both scoring systems failed to predict venous thrombosis. The incidence rate of thrombosis in intermediate risk revised IPSET-thrombosis (aged >60 years, JAK2-negative, and no history of thrombosis) was very low regardless of the treatment administered (0.9% and 0% per year with and without cytoreduction, respectively). Dynamic application of the revised IPSET-thrombosis showed a low rate of thrombosis when patients without history of prior thrombosis switched to a higher risk category after reaching 60 years of age. In conclusion, IPSET-thrombosis scores are useful for identifying patients at high risk of arterial thrombosis, whereas they fail to predict venous thrombosis. Controlled studies are needed to determine the appropriate treatment of ET patients assigned to the non-high-risk categories.

Association between serum alkaline phosphatase levels in late pregnancy and the incidence of venous thromboembolism postpartum: a retrospective cohort study

Background

Two previous studies found alkaline phosphatase (ALP) levels were related with the development of venous thromboembolism (VTE) in hospitalised patients. VTE is a leading cause of death during pregnancy and postpartum. No prior study has investigated the associations of ALP levels and VTE postpartum, and the related mechanisms remain unclear. This study aimed to investigate the associations between ALP levels and VTE postpartum, and to reveal the potential mechanisms.

Methods

In this retrospective cohort study, we included pregnant women who planned to deliver at the Department of Obstetrics and Gynecology in the three designated hospitals in a multicentre cohort of pregnant women in Wuhan, China, during two recruitment periods of January 1, 2018 to December 31, 2019, and May 14, 2020 to March 25, 2022. A total of 10,044 participants with serum ALP and whole blood hemoglobin measurements in late pregnancy (median, 37 (35, 39) weeks) were enrolled. The participants' incidences of VTE (deep venous thrombosis and/or pulmonary embolism) postpartum were confirmed from the medical records. Pregnant women with new-onset VTE postpartum (within 6 weeks after delivery) were confirmed as VTE cases.

Findings

Approximately 0.8% (79/10,044) of the pregnant women were diagnosed with VTE postpartum. In the unadjusted model, pregnant women with the lowest quintile of serum ALP levels (≤116 U/L) in late pregnancy had higher risk of VTE postpartum compared with those with the highest quintile (≥199 U/L) (OR, 2.83 [1.32, 6.05]). After adjusting for covariates of demographic, life style, birth outcomes, and other liver enzymes, pregnant women with the lowest quintile of serum ALP levels (≤116 U/L) in late pregnancy had increased risk of VTE postpartum compared with those with the highest quintile (≥199 U/L) (OR, 2.48 [1.14, 5.40]). A one standard deviation decrease of ln-transformed ALP levels were associated with elevated risk of VTE postpartum (OR, 1.29 [1.02, 1.62]). Significant negative associations of ALP with VTE were found in the unadjusted and adjusted models. The negative associations between ALP and VTE remained consistent in sensitivity analyses among participants with non-GDM, single pregnancy, non-preeclampsia, non-postpartum hemorrhage, non-extremely/very preterm and cesarean delivery. Decreased serum ALP levels significantly (P < 0.05) related to decreased hemoglobin, which was significantly (P < 0.05) related to increased risk of VTE postpartum. Decreased hemoglobin significantly (P < 0.05) mediated 7.59% of ALP-associated VTE postpartum.

Interpretation

This study suggested that low serum ALP levels in late pregnancy were associated with increased risk of VTE postpartum, and the ALP-associated VTE risk may be partially mediated by hemoglobin, suggesting that serum ALP in late pregnancy could be a promising biomarker for the prediction of VTE postpartum.

Funding

The National Natural Science Foundation of China, and the Program for HUST Academic Frontier Youth Team.

Effectiveness, safety, and costs of thromboprophylaxis with enoxaparin or unfractionated heparin in inpatients with obesity

Background

Obesity is a frequent and significant risk factor for venous thromboembolism (VTE) among hospitalized adults. Pharmacologic thromboprophylaxis can help prevent VTE, but real-world effectiveness, safety, and costs among inpatients with obesity are unknown.

Objective

This study aims to compare clinical and economic outcomes among adult medical inpatients with obesity who received thromboprophylaxis with enoxaparin or unfractionated heparin (UFH).

Methods

A retrospective cohort study was performed using the PINC AI™ Healthcare Database, which covers more than 850 hospitals in the United States. Patients included were ≥18 years old, had a primary or secondary discharge diagnosis of obesity [International Classification of Diseases (ICD)-9 diagnosis codes 278.01, 278.02, and 278.03; ICD-10 diagnosis codes E66.0x, E66.1, E66.2, E66.8, and E66.9], received ≥1 thromboprophylactic dose of enoxaparin (≤40 mg/day) or UFH (≤15,000 IU/day) during the index hospitalization, stayed ≥6 days in the hospital, and were discharged between 01 January 2010, and 30 September 2016. We excluded surgical patients, patients with pre-existing VTE, and those who received higher (treatment-level) doses or multiple types of anticoagulants. Multivariable regression models were constructed to compare enoxaparin with UFH based on the incidence of VTE, pulmonary embolism (PE)---------related mortality, overall in-hospital mortality, major bleeding, treatment costs, and total hospitalization costs during the index hospitalization and the 90 days after index discharge (readmission period).

Results

Among 67,193 inpatients who met the selection criteria, 44,367 (66%) and 22,826 (34%) received enoxaparin and UFH, respectively, during their index hospitalization. Demographic, visit-related, clinical, and hospital characteristics differed significantly between groups. Enoxaparin during index hospitalization was associated with 29%, 73%, 30%, and 39% decreases in the adjusted odds of VTE, PE-related mortality, in-hospital mortality, and major bleeding, respectively, compared with UFH (all p < 0.002). Compared with UFH, enoxaparin was associated with significantly lower total hospitalization costs during the index hospitalization and readmission periods.

Conclusions

Among adult inpatients with obesity, primary thromboprophylaxis with enoxaparin compared with UFH was associated with significantly lower risks of in-hospital VTE, major bleeding, PE-related mortality, overall in-hospital mortality, and hospitalization costs.

Duration of Initial Intensive Rivaroxaban Therapy for Patients With Venous Thromboembolism - Subanalysis of the J'xactly Study

Background: Rivaroxaban, a direct oral anticoagulant, is used as a first-line treatment to prevent venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE). However, whether 21 days is optimal for the initial treatment duration has not been investigated. Methods and Results: In this subanalysis of the prospective multicenter observational J'xactly study, which included 1,039 Japanese patients with acute symptomatic/asymptomatic DVT/PE who were prescribed rivaroxaban, the VTE recurrence rate and incidence of bleeding complications were assessed in 667 patients who underwent intensive rivaroxaban treatment (15 mg, twice daily) for a short (1-8 days), intermediate (9-16), or standard (17-24) duration. The short treatment duration group showed a tendency for increased VTE recurrence/aggravation compared with the standard treatment duration group (6.10% vs. 2.60% per patient-year). The intermediate treatment duration group showed a higher incidence of bleeding events than the standard treatment duration group (9.34% vs. 2.16% per patient-year), without major differences in patient characteristics between the groups. Conclusions: In this subanalysis of the real-world observational J'xactly study of VTE treatment and prevention in Japanese patients with acute symptomatic/asymptomatic DVT/PE, the standard initial intensive rivaroxaban treatment duration (17-24 days) appeared to be safe and effective, providing important insights into the clinical outcomes of the initial rivaroxaban treatment duration in this population.

Circulating adipokine concentrations and the risk of venous thromboembolism: A Mendelian randomization and mediation analysis

Background: Previous observational studies have suggested that circulating adipokine concentrations are related to a greater risk of venous thromboembolism (VTE). However, it remained unclear whether these observations reflect causality.

Objective: This study aimed to investigate the causal relationship between circulating adipokine concentrations (including adiponectin, leptin, PAI-1, MCP-1, leptin receptor, and RETN) and the risk of VTE and its subtypes (DVT and PE) and to determine whether circulating adipokine concentrations are a mediator of venous thromboembolic events in obese patients.

Methods: We used Mendelian randomization (MR) analyses to determine the effects of the body mass index (BMI), adiponectin, leptin, PAI-1, MCP-1, leptin receptor, and RETN levels on VTE, DVT, and PE in a cohort of 11,288 VTE cases, 5,632 DVT cases, 5,130 PE cases, and 254,771 controls. We then assessed the proportion of the effect of obesity on VTE, DVT, and PE explained by circulating leptin levels.

Result: Genetically predicted higher BMI was related to increased VTE (OR = 1.45, p &lt; 0.001), DVT (OR = 1.63, p &lt; 0.001), and PE (OR = 1.37, p &lt; 0.001) risk, and higher circulating leptin levels increase odds of VTE (OR = 1.96, q &lt; 0.001), DVT (OR = 2.52, q &lt; 0.001), and PE (OR = 2.26, q = 0.005). In addition, we found that the causal effect between elevated serum adiponectin and the decreased risk of VTE (OR = 0.85, p = 0.013, q = 0.053) and PE (OR = 0.81, p = 0.032, q = 0.083) and between MCP-1 and the reduced risk of VTE (OR = 0.88, p = 0.048, q = 0.143) is no longer significant after FDR adjustment. In MR mediation analysis, the mediation effect of circulating leptin levels in the causal pathway from BMI to PE was estimated to be 1.28 (0.95–1.71, p = 0.10), accounting for 39.14% of the total effect.

Conclusion: The circulating leptin level is a risk factor for VTE, DVT, and PE, but it might be a potential mediator of BMI on the risk of PE, and thus, interventions on the circulating leptin level in obesity might reduce the risk of PE. Adiponectin is a potential protective factor for both VTE and PE.