Environmental and Genetic Risk Factors Associated with Venous Thromboembolism

Thromboembolism in Children

OBJECTIVE

To study pediatric patients who were diagnosed with thrombosis between January 2009 and March 2020.

METHODS

Patients were evaluated with respect to thrombophilic risk factors, localization of the thrombus, response to treatment, and recurrence rates during the last 11 y.

RESULTS

Among 84 patients, 59 (70%) had venous thrombosis and 20 (24%) had arterial thrombosis. The number of documented thrombosis amongst hospitalized children in authors' hospital has increased over the years. It has been observed that the annual incidence of thromboembolism has increased after 2014. Thirteen patients were recorded between 2009 and 2014 and 71 patients between 2015 and 2020 (until March 2020). Exact thrombosis localization could not be detected in 5 patients. The median age of patients was 8 ± 5.95 (range 0-18). Fourteen children (16.9%) had a history of familial thrombosis. Genetic and/or acquired risk factors were detected in 81 (96.4%) of the patients. Overall, 64 patients (76.1%) had acquired risk factors such as infection (20.2%), catheterization (13.1%), liver disease (11.9%), mastoiditis (8.3%), liver transplantation (6%), hypoxic-ischemic encephalopathy (4.8%), dehydration (3.6%), trauma (3.6%) and cancer (2.4%). As genetic risk factors, the most common genetic mutations were PAI-1 4G>5G, MTHFR C677T, and MTHFR A1298C mutations. Twenty-eight (41.2%) patients had at least one genetic thrombophilic mutation. At least one homozygous mutation in 37 patients (44%) and at least one heterozygous mutation in 55 patients (65.4%) were detected.

CONCLUSIONS

The annual incidence of thrombosis has increased over the years. Genetic predisposition and acquired risk factors play an important role in etiology, treatment, and follow-up in children with thromboembolism. Especially, genetic predisposition is common. Thrombophilic risk factors should be investigated and optimal therapeutic and prophylactic measures should be promptly taken in children with thrombosis.

Massive Pulmonary Embolism Associated With Factor V Leiden Mutation in a Young Female on Oral Contraceptive Pills: A Case Report

Factor V Leiden (FVL) is the major genetic risk factor to predispose venous thromboembolism (VTE). We present a rare case of a 34-year-old Caucasian female heterozygous for this mutation and taking oral contraceptive pills (OCPs) for less than four months, who presented to the emergency department with acute onset of dyspnea and was diagnosed to have an isolated massive bilateral pulmonary embolism (PE). The patient was managed for six days in the hospital and was discharged on oral anticoagulants. The risk for VTE in patients with factor V Leiden and on oral contraceptive pills increases by 30-fold in heterozygous women and 100-fold in homozygous women. The risk of VTE in factor V Leiden seems to outweigh the benefit of contraception with oral contraceptive pills. This case suggests that thrombophilia screening should be considered only in patients with a positive first-degree family history of VTE, where necessary, to prevent any future thrombotic morbidity and mortality.

Multi-organ Thromboembolic Crisis: A Case Report of Concomitant Stroke, Myocardial Infarction, and Pulmonary Embolism

Management of acute coronary syndrome (ACS), cerebrovascular accident (CVA), and pulmonary embolism (PE) necessitates prompt intervention, as delayed treatment may lead to severe consequences. Each of these conditions presents significant challenges and carries a high risk of morbidity and mortality. We present the case of an 86-year-old female with a history of stage 4 urothelial carcinoma metastasized to the lungs, who presented to the emergency department (ED) with acute ischemic stroke (AIS), ST-segment elevation myocardial infarction (STEMI), and bilateral PE. We propose the term "multi-organ thromboembolic crisis" (MOTEC) to streamline the communication and management approach for patients experiencing critical thromboembolic events affecting multiple organ systems.

Identifying novel biomarkers using proteomics to predict cancer-associated thrombosis

Comprehensive protein analyses of plasma are made possible by high-throughput proteomic screens, which may help find new therapeutic targets and diagnostic biomarkers. Patients with cancer are frequently affected by venous thromboembolism (VTE). The limited predictive accuracy of current VTE risk assessment tools highlights the need for new, more targeted biomarkers. Although coagulation biomarkers for the diagnosis, prognosis, and treatment of VTE have been investigated, none of them have the necessary clinical validation or diagnostic accuracy. Proteomics holds the potential to uncover new biomarkers and thrombotic pathways that impact the risk of thrombosis. This review explores the fundamental methods used in proteomics and focuses on particular biomarkers found in VTE and cancer-associated thrombosis.

Association of Cardiovascular Health with the Incidence of Venous Thromboembolism: A Prospective Study of 275,149 Participants from the UK Biobank

BACKGROUND

 The Life's Essential 8 (LE8) score, recently proposed by the American Heart Association, represents a new paradigm for evaluating cardiovascular health (CVH). We aimed to explore the association between CVH, estimated using LE8, and venous thromboembolism (VTE) incidence.

METHODS

 A total of 275,149 participants were recruited from the UK Biobank and divided into high (LE8 score ≥ 80), moderate (LE8 score < 80 but ≥ 50), and low (LE8 score < 50) CVH groups. Restricted cubic spline analysis, the Kaplan-Meier method, and the Cox proportional hazards model were used to explore the association between CVH and VTE. The genetic predisposition to VTE was assessed with a polygenic risk score. Sensitivity analyses were performed to validate the results.

RESULTS

 During a median follow-up of 12.56 years, VTE developed in 506 (4.09%), 6,069 (2.78%), and 720 (1.66%) participants with low, moderate, and high CVH levels, respectively. Compared with the low CVH group, participants in the moderate and high CVH groups had a 23% (hazard ratio [HR]: 0.77; 95% confidence interval [CI]: 0.71-0.85) and 41% (HR: 0.59; 95% CI: 0.52-0.66) lower risk of VTE, respectively, after adjusting for demographic characteristics, medical history, socioeconomic status, and genetic predisposition. This association remained robust in multiple sensitivity analyses. Higher CVH levels led to a more pronounced reduction in the risk of VTE in females and could appreciably offset the genetic risk of VTE.

CONCLUSION

 Higher CVH levels were significantly associated with a lower incidence of VTE, encouraging efforts to increase LE8 scores in individuals.

Multimodal detection and analysis of microplastics in human thrombi from multiple anatomically distinct sites

BACKGROUND

Microplastic (MP) pollution has emerged as a significant environmental concern worldwide. While extensive research has focused on their presence in marine organisms and ecosystems, their potential impact on human health, particularly on the circulatory system, remains understudied. This project aimed to identify and quantify the mass concentrations, polymer types, and physical properties of MPs in human thrombi surgically retrieved from both arterial and venous systems at three anatomically distinct sites, namely, cerebral arteries in the brain, coronary arteries in the heart, and deep veins in the lower extremities. Furthermore, this study aimed to investigate the potential association between the levels of MPs and disease severity.

METHODS

Thrombus samples were collected from 30 patients who underwent thrombectomy procedures due to ischaemic stroke (IS), myocardial infarction (MI), or deep vein thrombosis (DVT). Pyrolysis-gas chromatography mass spectrometry (Py-GC/MS) was employed to identify and quantify the mass concentrations of the MPs. Laser direct infrared (LDIR) spectroscopy and scanning electron microscopy (SEM) were used to analyse the physical properties of the MPs. Demographic and clinical information were also examined. A rigorous quality control system was used to eliminate potential environmental contamination.

FINDINGS

MPs were detected by Py-GC/MS in 80% (24/30) of the thrombi obtained from patients with IS, MI, or DVT, with median concentrations of 61.75 μg/g, 141.80 μg/g, and 69.62 μg/g, respectively. Among the 10 target types of MP polymers, polyamide 66 (PA66), polyvinyl chloride (PVC), and polyethylene (PE) were identified. Further analyses suggested that higher concentrations of MPs may be associated with greater disease severity (adjusted β = 7.72, 95% CI: 2.01-13.43, p < 0.05). The level of D-dimer in the MP-detected group was significantly higher than that in the MP-undetected group (8.3 ± 1.5 μg/L vs 6.6 ± 0.5 μg/L, p < 0.001). Additionally, LDIR analysis showed that PE was dominant among the 15 types of identified MPs, accounting for 53.6% of all MPs, with a mean diameter of 35.6 μm. The shapes of the polymers detected using LDIR and SEM were found to be heterogeneous.

INTERPRETATION

This study presents both qualitative and quantitative evidence of the presence of MPs, and their mass concentrations, polymer types, and physical properties in thrombotic diseases through the use of multimodal detection methods. Higher concentrations of MPs may be associated with increased disease severity. Future research with a larger sample size is urgently needed to identify the sources of exposure and validate the observed trends in the study.

FUNDING

This study was funded by the SUMC Scientific Research Initiation Grant (SRIG, No. 009-510858038), Postdoctoral Research Initiation Grant (No. 202205230031-3), and the 2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant (No. 2020LKSFG02C).

Ability of Caprini and Padua risk-assessment models to predict venous thromboembolism in a nationwide Veterans Affairs study

OBJECTIVE

Venous thromboembolism (VTE) is a preventable complication of hospitalization. Risk-stratification is the cornerstone of prevention. The Caprini and Padua are two of the most commonly used risk-assessment models (RAMs) to quantify VTE risk. Both models perform well in select, high-risk cohorts. Although VTE RAMs were designed for use in all hospital admissions, they are mostly tested in select, high-risk cohorts. We aim to evaluate the two RAMs in a large, unselected cohort of patients.

METHODS

We analyzed consecutive first hospital admissions of 1,252,460 unique surgical and non-surgical patients to 1298 Veterans Affairs facilities nationwide between January 2016 and December 2021. Caprini and Padua scores were generated using the Veterans Affairs' national data repository. We determined the ability of the two RAMs to predict VTE within 90 days of admission. In secondary analyses, we evaluated prediction at 30 and 60 days, in surgical vs non-surgical patients, after excluding patients with upper extremity deep vein thrombosis, in patients hospitalized ≥72 hours, after including all-cause mortality in a composite outcome, and after accounting for prophylaxis in the predictive model. We used area under the receiver operating characteristic curves (AUCs) as the metric of prediction.

RESULTS

A total of 330,388 (26.4%) surgical and 922,072 (73.6%) non-surgical consecutively hospitalized patients (total N = 1,252,460) were analyzed. Caprini scores ranged from 0 to 28 (median, 4; interquartile range [IQR], 3-6); Padua scores ranged from 0-13 (median, 1; IQR, 1-3). The RAMs showed good calibration and higher scores were associated with higher VTE rates. VTE developed in 35,557 patients (2.8%) within 90 days of admission. The ability of both models to predict 90-day VTE was low (AUCs: Caprini, 0.56; 95% confidence interval [CI], 0.56-0.56; Padua, 0.59; 95% CI, 0.58-0.59). Prediction remained low for surgical (Caprini, 0.54; 95% CI, 0.53-0.54; Padua, 0.56; 95% CI, 0.56-0.57) and non-surgical patients (Caprini, 0.59; 95% CI, 0.58-0.59; Padua, 0.59; 95% CI, 0.59-0.60). There was no clinically meaningful change in predictive performance in any of the sensitivity analyses.

CONCLUSIONS

Caprini and Padua RAM scores have low ability to predict VTE events in a cohort of unselected consecutive hospitalizations. Improved VTE RAMs must be developed before they can be applied to a general hospital population.

Awareness and Knowledge of Venous Thromboembolism Among Saudi Adults in the Dawadmi Province: A Cross-Sectional Study

Background Venous thromboembolism (VTE) significantly contributes to the global disease burden. The annual incidence of VTE is one to two per 1,000 adults worldwide. We aimed to evaluate the awareness and knowledge of VTE risk factors, manifestations, prevention, and treatment options among the general adult population of Dawadmi, Riyadh, Saudi Arabia. Methodology We conducted a cross-sectional study using the self-designed and validated VTE knowledge questionnaire. A survey was conducted online via Google Documents, composed of 12 questions. Participants included in the study were over 18 years old, regardless of their medical history. However, medical students and healthcare providers were excluded. Results A total of 384 participants (46.4% men and 53.6% women) completed the survey; most respondents were between 18 and 28 years of age. Majority of the participants recognized that immobility, obesity, complicated surgery, road traffic accidents, smoking, and old age are the most common risk factors for VTE. However, more than half of the elderly and lower-educated participants did not identify complicated surgery and consumption of oral contraceptive pills as risk factors for VTE. Awareness of VTE was significantly higher among those with a family history of VTE and a graduate degree (p<0.001). Results showed a deficit of awareness and information about VTE, especially among males, those with low education, and elderly participants. Conclusion This study demonstrates the need for more awareness of VTE among the Saudi adult population. The urge to spread awareness and knowledge about VTE among the public in Dawadmi province is required.

Genomic science of risk prediction for venous thromboembolic disease: convenient clarification or compounding complexity

Venous thromboembolism (VTE) refers to abnormal blood clots in veins occurring in 1 to 2 per 1000 individuals every year. While anticoagulant treatment can prevent VTE, it increases the risk of bleeding. This emphasizes the importance of identifying individuals with a high risk of VTE and providing prophylactic interventions to these individuals to reduce both VTE and bleeding risks. Current risk assessment of VTE is based on the combination of mainly clinical risk factors. With the identification of an increasing number of genetic variants associated with the risk of VTE, the addition of genetic findings to clinical prediction models can improve risk prediction for VTE. Especially for individuals in high-risk situations, the added value of genetic findings to clinical prediction models may have benefits such as better prophylaxis of VTE and the reduced side effects of bleeding from unnecessary treatment. Nevertheless, the question of whether these models will eventually have clinical utility remains to be proven. Here, we review the current state of knowledge on genetic risk factors for VTE, explore genetic prediction models for VTE, and discuss their clinical implications and challenges.

Frequencies of VKORC1-1639G>A and rs397509427 in Patients on Warfarin and Healthy Syrian Subjects

Background

Vitamin K epoxide reductase complex subunit 1 (VKORC1) gene encodes a key enzyme with multiple cellular activities, namely, the reduction of vitamin K to its active form. VKORC1-1639G>A (rs9923231) is a common single nucleotide polymorphism with a crucial impact on warfarin dosing and possibly other physiological functions. This study aimed at investigating the frequencies of VKORC1-1639G>A alleles and genotypes in Syrian healthy subjects and patients on warfarin for different indications.

Methods

A total of 138 individuals were enrolled in this cross-sectional study. Genomic DNA was extracted from both patients on warfarin and healthy subjects, and polymerase chain reaction (PCR) specific amplicons were genotyped via standard sequencing which also allowed the detection of rs397509427. Comparisons of -1639G>A frequency with other populations were drawn.

Results

Of 94 patients on warfarin, 53 (56.38%) were with idiopathic venous thromboembolism (VTE). Despite comparable frequencies of the -1639A allele (47% and 50%), the AA and GA genotypes were at disparate frequencies of 93.2% versus 79.8% in the healthy subjects (n = 44) versus patients on warfarin, respectively. Carriers of the GG genotype were at a four-fold increased risk of VTE in comparison with those of the AA and GA genotypes (odds ratio (OR) = 4, 95% CI = 1.105 - 13.6, P = 0.0469). All study subjects were wild-type for the rs397509427 variant.

Conclusions

Our results prove a high -1639A prevalence in Syrian healthy subjects and patients on warfarin at frequencies comparable to other Mediterranean and Middle Eastern populations. The A allele carriers are at a lower VTE risk, whereas a global prevalence gradient of the G allele is suggested to be associated with VTE risk.

Clinical Investigation of Hereditary and Acquired Thrombophilic Factors in Patients with Venous and Arterial Thromboembolism

Background

The clinical relevance of thrombophilic laboratory factors, especially the "mild" ones, and the need for their screening is not generally recommended in venous (VTE) and/or arterial (ATE) thromboembolism.

Methods

Our aim was to investigate possible associations between comorbidities and 16 inherited/acquired "severe" and "mild" laboratory thrombophilic factors (detailed in introduction) in patients (n=348) with VTE/ATE without a serious trigger (high-risk surgical intervention, active cancer and/or chemo-radiotherapy). Cases with VTE/ATE were enrolled when the thrombotic event occurred under the age of 40, in case of positive family history, recurrent thromboembolism, idiopathic event or unusual location. Patients without a detailed thrombophilia screening or who suffered from both ATE/VTE were excluded to find potential distinct thrombosis type specific thrombophilic risks. The possible role of "mild" factor accumulation was also investigated in VTE (n=266).

Results

Elevation of factor VIII clotting activity was associated with VTE rather than ATE. Varicose veins together with postthrombotic syndrome were strongly related to several "mild" factors. Besides "severe" we found that the "mild" thrombophilic factors were also strongly associated with VTE/ATE. Comorbidities/conditions such as diabetes and smoking were generally associated with hyperlipidemia; moreover, both had a correlation with lipoprotein (a) in VTE. We also revealed an important contribution of "mild" factors in increasing trends of several types and localizations of VTE.

Conclusion

In summary, besides the "severe" thrombophilic factors, the "mild" ones also seem to play a non-negligible role in the manifestation of thrombosis, especially in combination. Therefore, an extended screening might be useful in the personalized recommendation of antithrombotic prophylaxis.

Genetic overlap for ten cardiovascular diseases: A comprehensive gene-centric pleiotropic association analysis and Mendelian randomization study

Recent studies suggest that pleiotropic effects may explain the genetic architecture of cardiovascular diseases (CVDs). We conducted a comprehensive gene-centric pleiotropic association analysis for ten CVDs using genome-wide association study (GWAS) summary statistics to identify pleiotropic genes and pathways that may underlie multiple CVDs. We found shared genetic mechanisms underlying the pathophysiology of CVDs, with over two-thirds of the diseases exhibiting common genes and single-nucleotide polymorphisms (SNPs). Significant positive genetic correlations were observed in more than half of paired CVDs. Additionally, we investigated the pleiotropic genes shared between different CVDs, as well as their functional pathways and distribution in different tissues. Moreover, six hub genes, including ALDH2, XPO1, HSPA1L, ESR2, WDR12, and RAB1A, as well as 26 targeted potential drugs, were identified. Our study provides further evidence for the pleiotropic effects of genetic variants on CVDs and highlights the importance of considering pleiotropy in genetic association studies.

Venous thromboembolism following surgical management of proximal humerus fractures: a systematic review

Background

Currently, there is limited information on the incidence of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE) after surgical treatment of proximal humerus fractures (PHFs). Therefore, the purpose of this systematic review is to evaluate the incidence of VTE, DVT, and PE following surgery for PHFs.

Methods

A comprehensive search of several databases was performed from inception to May 27, 2022. Studies were screened and evaluated by 2 reviewers independently utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Only original, English studies that evaluated the incidences of VTE following surgical management of PHFs were included. Surgical procedures consisted of shoulder arthroplasty (SA) including both hemiarthroplasty (Hemi) and reverse shoulder arthroplasty (RSA) in addition to open reduction and internal fixation (ORIF). A pooled incidence for postoperative DVT, PE, and overall VTE was reported.

Results

Twelve studies met the inclusion and exclusion criteria, encompassing a total of 18,238 patients. The overall DVT, PE, and VTE rates were 0.14%, 0.59%, and 0.7%, respectively. VTE was more frequently reported after SA than ORIF, (1.27% vs. 0.53%, respectively). Among SA patients, a higher rate of DVT was seen with RSA (1.2%) with the lowest DVT rate was observed for ORIF with 0.03%.

Conclusions

Symptomatic VTEs following surgical treatment of PHFs, are rare, yet still relevant as a worrisome postoperative complication. Among the various procedures, VTE was the most frequently reported after SA when compared to ORIF, with RSA having the highest VTE rate.

Association between uric acid and risk of venous thromboembolism in East Asian populations: a cohort and Mendelian randomization study

Background

Serum uric acid (SUA) levels have been associated with an increased risk and recurrence of venous thromboembolism (VTE) in European populations, but the potential causal relationship remains unclear. Large-scale studies on the association between SUA and VTE in East Asian populations are lacking, despite the high prevalence of hyperuricemia in this region. To address this, we conducted a cohort analysis and a two-sample Mendelian randomization (MR) study in East Asian populations.

Methods

We collected data on VTE patients from the China Pulmonary Thromboembolism Registry Study (CURES) and compared them to controls obtained from the China Health and Retirement Longitudinal Survey (CHARLS). Propensity score matching (PSM) and cubic-spline models were applied to assess the effect of SUA on VTE risk while adjusting for multiple covariates. We also performed two-sample MR analyses to infer potential causality based on summary statistics from Genome-wide Association Studies (GWAS) of SUA and VTE in the East Asian population.

Findings

We found that the SUA levels were higher in VTE patients (317.95 mmol/L) compared to the general population (295.75 mmol/L), and SUA ≥ 325 mmol/L was associated with an increased risk of VTE recurrence (P-value = 0.0001). The univariable MR suggested a causal relationship between elevated SUA and higher VTE risk (Pinverse variance weighted < 0.05), and multivariable MR showed that elevated SUA levels continued to promote the development of VTE after adjusting for multiple covariates (Pmultivariable residual < 0.05). Sensitivity analyses produced similar results for these estimations.

Interpretation

Our study provides evidence supporting a robust positive association between SUA and VTE in the East Asian population, and MR analyses suggest that this association is likely to be causal. Our findings underscore the importance of monitoring SUA levels in VTE prevention and call for urgent action to address the growing burden of hyperuricemia in the Asia-Pacific region.

Funding

This research was funded by Beijing Nova Program (No. Z211100002121057), National Natural Science Foundation of China (No. 82100065 and No. 62350004), CAMS Innovation Fund for Medical Sciences (No. 2021-I2M-1-061 and No. 2021-1-I2M-001), Elite Medical Professionals project of China-Japan Friendship Hospital (No. ZRJY2021-QM12), National Key Research and Development Project (No. 2021YFF1201200 and No. 2022YFC3341004).

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.

Serum levels of lead are associated with venous thromboembolism: a retrospective study based on the NHANES database (1999 to 2018)

Background

Venous thromboembolism (VTE) is a common clinical problem. While lead toxicity is known to affect the nervous, hematopoietic system, skeletal, and cardiovascular system, the relationship between blood lead levels and VTE remains unclear. This study explored whether there is a correlation between the levels of serum lead and VTE through a retrospective analysis based on data from the National Health and Nutrition Examination Survey (NHANES), so as to provide a reference for follow-up research and clinical practice.

Methods

According to the inclusion and exclusion criteria, subjects were enrolled from the NHANES (1999 to 2018) database and divided into a VTE group and a non-VTE group. The factors related to VTE were analyzed by single factor and multiple factor logistic regression analysis.

Results

A total of 31,081 subjects were included, of which 59 had VTE (0.19%). The higher the levels of serum lead, the higher the incidence of VTE. The univariate analysis revealed that age, male sex, history of cigarette use, hypertension, diabetes, and serum lead levels were factors associated with VTE in the population from the NHANES database. Further multivariate analysis revealed that age, history of cigarette use, hypertension, diabetes, and serum lead levels were factors associated with VTE.

Conclusions

The findings of this study suggest that higher serum levels of lead may be associated with VTE.

Leisure sedentary behaviour increases the risk of venous thromboembolism: a Mendelian randomisation study

BACKGROUND

Venous thromboembolism (VTE) is a substantial contributor to the global burden of disease. Observational studies have suggested that leisure sedentary behaviours (LSB) are related to the risk of VTE; however, the causal role of LSB in VTE remains unclear.

METHODS

Using data obtained from genome-wide association studies in the UK Biobank (N = 422,218), we identified 84, 21, and 4 single nucleotide polymorphisms (SNPs) related to sedentary television (TV) watching, computer use, and driving, respectively. These SNPs were employed as instrumental variables. Summary statistics for SNP-VTE associations was obtained from the FinnGen study (5,403 cases and 130,235 controls). Two-sample Mendelian randomisation (MR) analyses were performed using inverse-variance weighted (IVW), MR-Egger,weighted median, and weighted mode approaches. Sensitivity analyses were conducted to ensure robustness of the results.

RESULTS

The main IVW approach demonstrated a positive association between the genetically predicted sedentary TV watching and the risk of VTE [odds ratio (OR):1.35, 95% confidence interval (CI):1.02-1.80, P = 0.039]. However, no significant association was observed for genetically predicted sedentary computer use or driving and VTE risk. The results from our series of sensitivity analyses, including Cochran's Q test, MR-Egger intercept test, and MR-Pleiotropy RESidual Sum and Outlier method, further supported these findings.

CONCLUSION

This study provides evidence of an association between genetically predicted sedentary TV watching and the risk of VTE. Further studies are required to elucidate the underlying causal mechanisms.

Elevated plasma complement factor H related 5 protein is associated with venous thromboembolism

Venous thromboembolism (VTE) is a common, multi-causal disease with potentially serious short- and long-term complications. In clinical practice, there is a need for improved plasma biomarker-based tools for VTE diagnosis and risk prediction. Here we show, using proteomics profiling to screen plasma from patients with suspected acute VTE, and several case-control studies for VTE, how Complement Factor H Related 5 protein (CFHR5), a regulator of the alternative pathway of complement activation, is a VTE-associated plasma biomarker. In plasma, higher CFHR5 levels are associated with increased thrombin generation potential and recombinant CFHR5 enhanced platelet activation in vitro. GWAS analysis of ~52,000 participants identifies six loci associated with CFHR5 plasma levels, but Mendelian randomization do not demonstrate causality between CFHR5 and VTE. Our results indicate an important role for the regulation of the alternative pathway of complement activation in VTE and that CFHR5 represents a potential diagnostic and/or risk predictive plasma biomarker.

Pulmonary thromboembolism and obesity in forensic pathologic case work

328 autopsy cases of fatal pulmonary thromboembolism (PE) were compared to 984 age- and sex-matched controls to evaluate the association between obesity and PE in a forensic context. Both PE and control cases had a mean age of 67,8 years (male 62,9 years, females 71,7 years). The percentage of morbidly obese persons with a body mass index (BMI) of above 40 or abdominal subcutaneous adipose tissue of above 4 cm was higher in the PE group (8,39% vs. 4,67% and 29.45% vs. 23.40%, respectively). On the other side, that of very slim persons (BMI below 18.5 or adipose tissue below 3 cm) was significantly smaller (4,27% vs. 7,52% and 47.55% vs. 56,60%). We thus found a strong association between being overweight and death from PE, while slim persons seem to be at an advantage. As the group of underweight persons includes those suffering from chronic diseases with reduced mobility or hypercoagulability (e.g. tumor kachexia or sarkopenia due to immobilisation), this finding is to some extent unexpected.

The Thresholds of Caprini Score Associated With Increased Risk of Venous Thromboembolism Across Different Specialties: A Systematic Review

OBJECTIVE

Estimation of the specific thresholds of the Caprini risk score (CRS) that are associated with the increased incidence of venous thromboembolism (VTE) across different specialties, including identifying the highest level of risk.

BACKGROUND

Accurate risk assessment remains an important but often challenging aspect of VTE prophylaxis. One well-established risk assessment model is CRS, which has been validated in thousands of patients from many different medical and surgical specialties.

METHODS

A search of MEDLINE and the Cochrane Library was performed in March 2022. Manuscripts that reported on (1) patients admitted to medical or surgical departments and (2) had their VTE risk assessed by CRS and (3) reported on the correlation between the score and VTE incidence, were included in the analysis.

RESULTS

A total of 4562 references were identified, and the full text of 202 papers was assessed for eligibility. The correlation between CRS and VTE incidence was reported in 68 studies that enrolled 4,207,895 patients. In all specialties, a significant increase in VTE incidence was observed in patients with a CRS of ≥5. In most specialties thresholds of ≥7, ≥9, and ≥11 to 12 were associated with dramatically increased incidences of VTE. In COVID-19, cancer, trauma, vascular, general, head and neck, and thoracic surgery patients with ≥9 and ≥11 to 12 scores the VTE incidence was extremely high (ranging from 13% to 47%).

CONCLUSION

The Caprini score is being used increasingly to predict VTE in many medical and surgical specialties. In most cases, the VTE risk for individual patients increases dramatically at a threshold CRS of 7 to 11.

Forensic Pathological Analysis of Death Due to Pulmonary Thromboembolism: A Retrospective Study Based on 145 Cases

ABSTRACT

Pulmonary thromboembolism (PTE) is a common cause of sudden unexpected death in forensic and clinical practice. Although the prevention of thrombosis has been paid more attention in clinical practice in recent years, the number of deaths due to PTE remains extensive. In the present study, 145 cases of fatal PTE were collected and retrospectively analyzed from 2001 to 2020 at the School of Forensic Medicine, China Medical University in Liaoning Province, northeast of China. The demographic characteristics, risk factors of PTE, origins of thrombi, and time interval from the occurrence of main risk factors to PTE were retrospectively analyzed. The 40 to 59 age group accounted for the 51.0% of the total cases. Immobilization, trauma (especially fracture of the pelvis, femur, tibia, or fibula), surgery, cesarean section, and mental disorders were the top 5 high-risk factors. Among the involved cases, 92.9% of the PTE (130/140) occurred within 60 days and peak at 8 to 15 days after the exposure of main risk factors. According to the autopsy findings, 87.6% of the thrombi blocked the bilateral pulmonary arteries at pulmonary hilus, with a maximum diameter of 1.6 cm and a maximum length of 21.9 cm, which were mainly derived from lower limb (65.5%) or pelvic veins (10.3%). Although the embolus limited the pulmonary circulation, there is no difference on the ratio of lung-to-heart weight between PTE and the disease-free accident victims. Overall, our present retrospective study provides important information for the forensic analysis on the cause of death and potential guidance on clinical prevention of PTE.

Changes and significance of vascular endothelial injury markers in patients with diabetes mellitus and pulmonary thromboembolism

BACKGROUND

To investigate the changes and clinical significance of vascular endothelial injury markers in type 2 diabetes mellitus (T2DM) complicated with pulmonary embolism (PE).

METHODS

This prospective study enrolled patients with T2DM hospitalized in one hospital from January 2021 to June 2022. Soluble thrombomodulin (sTM) (ELISA), von Willebrand factor (vWF) (ELISA), and circulating endothelial cells (CECs) (flow cytometry) were measured. PE was diagnosed by computed tomography pulmonary angiography (CTPA).

RESULTS

Thirty participants were enrolled in each group. The plasma levels of sTM (151.22 ± 120.57 vs. 532.93 ± 243.82 vs. 1016.51 ± 218.00 pg/mL, P < 0.001) and vWF (9.63 ± 2.73 vs. 11.50 ± 2.17 vs. 18.02 ± 3.40 ng/mL, P < 0.001) and the percentage of CECs (0.17 ± 0.46 vs. 0.30 ± 0.08 vs. 0.56 ± 0.18%, P < 0.001) gradually increased from the control group to the T2DM group to the T2DM + PE group. sTM (OR = 1.002, 95%CI: 1.002-1.025, P = 0.022) and vWF (OR = 1.168, 95%CI: 1.168-2.916, P = 0.009) were associated with T2DM + PE. sTM > 676.68 pg/mL for the diagnosis of T2DM + PE achieved an AUC of 0.973, while vWF > 13.75 ng/mL achieved an AUC of 0.954. The combination of sTM and vWF above their cutoff points achieved an AUC of 0.993, with 100% sensitivity and 96.7% specificity.

CONCLUSIONS

Patients with T2DM show endothelial injury and dysfunction, which were worse in patients with T2DM and PE. High sTM and vWF levels have certain clinical predictive values for screening T2DM accompanied by PE.

An Exploratory Study Using Next-Generation Sequencing to Identify Prothrombotic Variants in Patients with Cerebral Vein Thrombosis

Prothrombotic hereditary risk factors for cerebral vein thrombosis (CVT) are of clinical interest to better understand the underlying pathophysiology and stratify patients for the risk of recurrence. This study explores prothrombotic risk factors in CVT patients. An initial screening in patients of the outpatient clinic of the Department of Transfusion Medicine and Hemostaseology of the University Hospital Erlangen, Germany, revealed 183 patients with a history of CVT. An initial screening identified a number of common prothrombic risk factors, including Factor V Leiden (rs6025) and Prothrombin G20210A (rs1799963). All patients without relevant findings (58 individuals) were invited to participate in a subsequent genetic analysis of 55 relevant genes using next-generation sequencing (NGS). Three intron variants (ADAMTS13: rs28446901, FN1: rs56380797, rs35343655) were identified to occur with a significantly higher frequency in the CVT patient cohort compared to the general European population. Furthermore, the combined prevalence of at least two of four potentially prothrombic variants (FGA (rs6050), F13A1 (rs5985), ITGB3 (rs5918), and PROCR (rs867186)) was significantly higher in the CVT subjects. The possible impact of the identified variants on CVT is discussed.

Thrombosis and cachexia in cancer: two partners in crime?

Among cancer patients, thrombosis and cachexia are major causes of morbidity and mortality. Although the two may occur together, little is known about their possible relationship. Thus, a literature review was conducted by screening the databases PubMed, Scopus, SciELO, Medline and Web of Science. To summarize, cancer-associated thrombosis (CAT) and cancer-associated cachexia (CAC) seem to share several patient-, tumour- and treatment-related risk factors. Inflammation alongside metabolic and endocrine derangement is the potential missing link between CAT, CAC and cancer. Many key players, including specific pro-inflammatory cytokines, immune cells and hormones, appear to be implicated in both thrombosis and cachexia, representing attractive predictive markers and potential therapeutic targets. Altogether, the current evidence suggests a link between CAT and CAC, however, epidemiological studies are required to explore this potential relationship. Given the high incidence and negative impact of both diseases, further studies are needed for the better management of cancer patients.

Ability of Caprini and Padua Risk-Assessment Models to Predict Venous Thromboembolism in a Nationwide Study

Background

Venous thromboembolism (VTE) is a preventable complication of hospitalization. Risk-stratification is the cornerstone of prevention. The Caprini and Padua are the most commonly used risk-assessment models to quantify VTE risk. Both models perform well in select, high-risk cohorts. While VTE risk-stratification is recommended for all hospital admissions, few studies have evaluated the models in a large, unselected cohort of patients.

Methods

We analyzed consecutive first hospital admissions of 1,252,460 unique surgical and non-surgical patients to 1,298 VA facilities nationwide between January 2016 and December 2021. Caprini and Padua scores were generated using the VA's national data repository. We first assessed the ability of the two RAMs to predict VTE within 90 days of admission. In secondary analyses, we evaluated prediction at 30 and 60 days, in surgical versus non-surgical patients, after excluding patients with upper extremity DVT, in patients hospitalized ≥72 hours, after including all-cause mortality in the composite outcome, and after accounting for prophylaxis in the predictive model. We used area under the receiver-operating characteristic curves (AUC) as the metric of prediction.

Results

A total of 330,388 (26.4%) surgical and 922,072 (73.6%) non-surgical consecutively hospitalized patients (total n=1,252,460) were analyzed. Caprini scores ranged from 0-28 (median, interquartile range: 4, 3-6); Padua scores ranged from 0-13 (1, 1-3). The RAMs showed good calibration and higher scores were associated with higher VTE rates. VTE developed in 35,557 patients (2.8%) within 90 days of admission. The ability of both models to predict 90-day VTE was low (AUCs: Caprini 0.56 [95% CI 0.56-0.56], Padua 0.59 [0.58-0.59]). Prediction remained low for surgical (Caprini 0.54 [0.53-0.54], Padua 0.56 [0.56-0.57]) and non-surgical patients (Caprini 0.59 [0.58-0.59], Padua 0.59 [0.59-0.60]). There was no clinically meaningful change in predictive performance in patients admitted for ≥72 hours, after excluding upper extremity DVT from the outcome, after including all-cause mortality in the outcome, or after accounting for ongoing VTE prophylaxis.

Conclusions

Caprini and Padua risk-assessment model scores have low ability to predict VTE events in a cohort of unselected consecutive hospitalizations. Improved VTE risk-assessment models must be developed before they can be applied to a general hospital population.

Plasma protein and venous thromboembolism: prospective cohort and mendelian randomisation analyses

We conducted cohort and Mendelian randomisation (MR) analyses to examine the associations of circulating proteins with risk of venous thromboembolism (VTE) to provide evidence basis for disease prevention and drug development. Cohort analysis was performed in 11 803 participants without baseline VTE. Cox regression was used to estimate the associations between 257 proteins and VTE risk. A machine-learning model was constructed to compare the importance of identified proteins and traditional risk factors. Genetic association data on VTE were obtained from a genome-wide meta-analysis (26 066 cases and 624 053 controls) and FinnGen (14 454 cases and 294 700 controls). The cohort analysis, including 353 incident VTE cases diagnosed during a 6.6-year follow-up, identified 21 proteins associated with VTE risk after false discovery rate correction. The machine-learning model indicated that body mass index and von Willebrand factor (vWF) made the same as well as most of the contributions to the overall model prediction. MR analysis found that genetically predicted levels of vWF, SERPINE1 (plasminogen activator inhibitor 1, known as PAI-1), EPHB4 (ephrin type-B receptor 4), TYRO3 (tyrosine-protein kinase receptor TYRO3), TNFRSF11A (tumour necrosis factor receptor superfamily member 11A), and BOC (brother of CDO) were causally associated with VTE risk.

Temporal trend in venous thromboembolism hospitalization rates in Brazilian older adults, 2010-2020

Aging is one of the main risk factors for venous thromboembolism (VTE). Changes in prevention, diagnosis, and treatment strategies for this condition in recent years require an analysis of its rates in health services. The objective of this study was to analyze a temporal trend of hospitalizations for VTE in Brazilian older adults. This ecological time series study used data from the Hospital Information System (HIS) on VTE hospitalizations from 2010 to 2020, selecting admissions with the main diagnosis of pulmonary thromboembolism (PTE) (I.26.0, I.26.9) and deep vein thrombosis (DVT) (I.80.0, I80.1, I80.2, I80.3, I80.8, I80.9). Hospitalization rates were calculated for each year and the Prais-Winsten. In Brazil, the trend of hospitalizations for VTE decreased, with an annual percentage change of - 40.71 (confidence interval [CI] - 50.46; - 29.04). DVT decreased, with an annual percentage change of - 43.14 (95% confidence interval [CI] - 51.36; - 33.54). All Brazilian regions showed a downward trend in hospitalizations for VTE and DVT, except for the Northeast region, which remained stable. Conversely, the trend of hospitalizations for PTE showed an upward in Brazil, with an annual percentage change of 4.33 (95% CI 1.26; 7.48). An upward trend was observed in hospitalizations for PTE in the Northeast region, and a stationary trend was observed in the other regions. The results showed a downward trend in hospitalization rates for DVT and an upward trend for PTE. The study indicates regional differences in rates and trends.

Risk Factors of Venous Thromboembolism in Inpatients With Colorectal Cancer in China

To explore the risk factors for venous thromboembolism (VTE) in inpatients with colorectal cancer. The demographic factors, comorbidities, and hematological indices of patients with colorectal cancer treated in our hospital from 2016 to 2021 were collected and recorded. Venous thromboembolism events, including deep venous thrombosis and/or pulmonary embolism, were recorded and the patients were divided into the VTE group and the non-VTE group. We compared clinical data between the two groups and explored risk factors for VTE. Comparing the clinical data of 293 cases of non-VTE group and 235 cases of VTE group, we found significant differences in age, smoking, temperature, amount of blood loss, differentiation degree, peripherally inserted central catheter (PICC), radiotherapy, anemia, infection, white blood cell count, prothrombin time (PT), PT%, prothrombin ratio, international normalized ratio, thrombin time, CA199 and CEA between the two groups (P < 0.05). Logistic regression analysis showed that age (P = 0.0444), temperature (P = 0.0317), amount of blood loss (P = 0.0067), PICC (P < 0.0001), chemotherapy (P = 0.0459), anemia (P = 0.0007), international normalized ratio (P = 0.003) and CA199 (p = 0.0234) were independent risk factors for VTE. Receiver operating characteristic curve analysis showed that the amount of blood loss predicted thrombosis better (AUC = 0.778, P < 0.001), when the cutoff value was 20 mL, the sensitivity was 76.17%, and the specificity was 79.18%, respectively. And PICC predicted thrombosis better (AUC = 0.808, P < 0.001), the sensitivity was 70.21%, and the specificity was 91.47%, respectively. Clinical parameters are associated with VTE in inpatients with colorectal cancer, which will help to guide clinicians to take effective measures to improve the patients' prognosis.

Genetic association and causal inference between lung function and venous thromboembolism

BACKGROUND

Previous studies have indicated that lower lung function is related to a higher risk of venous thromboembolism (VTE). However, causal inferences may be affected by confounders, coheritability or reverse causality. We aimed to explore the causal association between lung function and VTE.

METHODS

Summary data from public genome-wide association studies (GWAS) for lung function and VTE were obtained from published meta-analysis studies and the FinnGen consortium, respectively. Independent genetic variables significantly related to exposure were filtered as proxy instruments. We adopted linkage disequilibrium score regression (LDSC) and two-sample Mendelian randomization (MR) analyses to infer the genetic backgrounds and causal associations between different lung functions and VTE events.

RESULTS

LDSC showed a genetic correlation between forced expiratory volume in one second (FEV1) and deep vein thrombosis (DVT) (rg = - 0.189, P = 0.005). In univariate MR (UVMR), there was suggestive evidence for causal associations of genetically predicted force vital capacity (FVC) with DVT (odds ratio (OR) 0.774; 95% confidence interval (CI) 0.641-0.934) via forwards analysis and genetically predicted pulmonary embolism (PE) with FVC (OR 0.989; 95% CI 0.979-0.999) via reverse analysis. Multivariate MR (MVMR) analyses of lung function-specific SNPs suggested no significant direct effects of lung function on VTE, and vice versa. Of note is the borderline causal effect of PE on FEV1 (OR 0.921; 95% CI 0.848-1.000).

CONCLUSIONS

Our findings identified a coheritability of FEV1 (significant) and FVC (suggestive) with DVT. There was no convincing causal relationship between lung function and the risk of VTE events. The borderline causal effect of PE on FEV1 and the significant genetic correlation of FEV1 with DVT may have clinical implications for improving the quality of existing prevention and intervention strategies.

Incidence of Cerebral Venous Thrombosis: A Population-Based Study, Systematic Review, and Meta-Analysis

BACKGROUND

Studying the baseline incidence of cerebral venous thrombosis (CVT) prior to COVID-19 and the limitations of how this has been previously reported in the literature will help improve understanding of this disease and how risks may have changed in the post-COVID era.

METHODS

We examined CVT incidence using linked administrative data in British Columbia, Canada (population 5.2 million). To contextualize our findings, we also examined CVT incidence in the published literature and searched MEDLINE and EMBASE for article titles and abstracts up to Nov 2, 2021 on CVT incidence in adults. We performed abstract screening and full-text review prior to data extraction and explored associations between CVT incidence and year of study, geographic location, and study quality with meta-analyses and meta-regression. A random-effects restricted maximum likelihood model was used. Publication bias was assessed using the Egger tests and using visual inspection of the funnel plot for symmetry.

RESULTS

There were 554 unique CVT cases (mean age 50.9 years, 55.4% women) in British Columbia from 2000 to 2017; overall annual incidence was 8.7 (95%CI' 8.0-9.4) per million. Incidence increased over time in men across the entire study period, and from 2011 to 2017 in women. We identified 22 other studies on CVT incidence before 2020 (21/23 total studies included in meta-analysis). Annual incidence overall was 12.1 (95% CI' 9.9-14.3) per million with significant between-study heterogeneity (I2 98.8%, Qp-value<0.001). There were no significant associations on meta-regression between incidence and study year, study quality score, or gross national income per capita of the study country. Visual inspection of the funnel plot and a significant Egger test (z=2.8, P<0.01) suggested possible publication bias.

CONCLUSIONS

Incidence of CVT in Canadian data increased over time but remained lower than in other population-based studies. Significant heterogeneity exists in the literature, which may be subject to publication bias.

Low ambient temperature might trigger the symptom onset of pulmonary embolism: A nationwide case-crossover study at hourly level in China

BACKGROUND

Pulmonary embolism (PE) is an important cause of death and its seasonality has long been observed. Very few epidemiological studies have explored the potential role of ambient temperature in PE symptom onset, especially at the hourly level.

METHODS

We conducted a time-stratified case-crossover study among 17,903 PE patients with hourly onset of symptom from 1590 hospitals across China between January 2015 and September 2020. Conditional logistic regression model combined with distributed lag non-linear models were used to explore the associations between hourly ambient temperature and PE symptom onset. The attributable fractions due to non-optimum temperature were calculated.

RESULTS

The exposure-response relationship curve was inverse and almost linear. Lower temperature was significantly associated with higher risk of PE symptom onset when temperature was below 18 °C. This risk occurred immediately at the same hour, attenuated thereafter, and became nonsignificant at approximately 72 h after exposure. Compared with the referent temperature (P₉₉, 34.1 °C), the odds ratio of PE symptom onset associated with extremely low temperature (P₁, -16.1 °C) over lag 0-72 h was 1.63 (95%CI: 1.23, 2.16). Low temperature may account for 16.19 % of the symptom onset nationally with higher proportion in the south of China. The effects were stronger in older adults, males, and cold seasons.

CONCLUSIONS

We provided the first-hand robust evidence that transient exposure (at the hourly level) to low temperature might trigger the symptom onset of PE and constitute a considerable burden for PE patients. Targeted protections and health education are needed for susceptible populations.

Thromboembolic Events in Patients with Influenza: A Scoping Review

INTRODUCTION

Influenza is an acute respiratory infection that usually causes a short-term and self-limiting illness. However, in high-risk populations, this can lead to several complications, with an increase in mortality. Aside from the well-known extrapulmonary complications, several studies have investigated the relationship between influenza and acute cardio and cerebrovascular events. Reviews of the thromboembolic complications associated with influenza are lacking.

OBJECTIVES

the study aims to conduct a scoping review to analyze the epidemiological and clinical characteristics of patients suffering from influenza and thromboembolic complications.

MATERIALS AND METHODS

A computerized search of historical published cases using PubMed and the terms "influenza" or "flu" and "thrombosis", "embolism", "thromboembolism", "stroke", or "infarct" for the last twenty-five years was conducted. Only articles reporting detailed data on patients with thromboembolic complications of laboratory-confirmed influenza were considered eligible for inclusion in the scoping review.

RESULTS

Fifty-eight cases with laboratory documented influenza A or B and a related intravascular thrombosis were retrieved. Their characteristics were analyzed along with those of a patient who motivated our search. The localizations of thromboembolic events were pulmonary embolism 21/58 (36.2%), DVT 12/58 (20.6%), DVT and pulmonary embolism 3/58 (5.1%), acute ischemic stroke 11/58 (18.9%), arterial thrombosis 4/58 (6.8%), and acute myocardial infarction 5/58 (8.6%).

DISCUSSION

Our findings are important in clarifying which thromboembolic complications are more frequent in adults and children with influenza. Symptoms of pulmonary embolism and influenza can be very similar, so a careful clinical evaluation is required for proper patient management, possible instrumental deepening, and appropriate pharmacological interventions, especially for patients with respiratory failure.

Perioperative Prevention of Venous Thromboembolism in Abdominal Surgery Patients Based on the Caprini or the Padua Risk Score-A Single Centre Prospective Observational Study

Surgical patients should receive perioperative thromboprophylaxis based on risk assessment, and the Caprini score is validated for this purpose. Whether the Padua score, originally devised for medical patients, can be useful in surgical patients remains to be fully clarified. This study aimed to evaluate perioperative thromboprophylaxis based on the Caprini or the Padua score in elective abdominal surgery. A total of 223 patients undergoing elective abdominal surgery for malignant or benign disease were prospectively evaluated. The patients were divided into two groups in which thromboprophylaxis was prescribed according to either the Caprini score (n = 122) or the Padua score (n = 101). Patients with high-risk scores in both groups received nadroparin. The alternate risk score in each group was calculated for evaluation purposes only. During a 3-month follow-up, we assessed patients for symptomatic venous thromboembolism (VTE), bleeding, or mortality. In the Caprini score group, 87 patients (71%) had a high risk for VTE (≥5 points), while 38 patients (38%) had a high risk for VTE (≥4 points) in the Padua score group; p < 0.00001. The overall correlation between the Caprini and Padua scores was moderate (r= 0.619), with 85 patients having high Caprini and discordant Padua scores. Ten patients died during follow-up (4.5%), and five developed non-fatal symptomatic VTE (2.2%). Among the five major bleeding incidents recorded (1.8%), two cases were possibly associated with pharmacological thromboprophylaxis. The incidence of adverse outcomes did not differ between the two groups. The odds ratio for adverse outcomes was significantly higher with a high Caprini or Padua risk score, malignant disease, age ≥65 years, and active smoking. We found no significant differences in adverse outcomes between abdominal surgical patients who received perioperative thromboprophylaxis based on either the Caprini or the Padua risk score. However, a discordant Padua score was noted in almost 40% of patients who had a high Caprini score, suggesting that the latter may be more sensitive than the Padua score in surgical patients.

Correlation of Air Pollution and Prevalence of Acute Pulmonary Embolism in Northern Thailand

BACKGROUND

The relationship between the level of air pollution and acute pulmonary embolism (APE) has had inconsistent results.

OBJECTIVE

This study aimed to analyze the relationship between the high level of air pollution exposure and APE.

METHODS

A ten-year retrospective cohort, single-center study was performed on patients diagnosed with APE from October 2010 to December 2020. The association between air pollution and monthly APE case diagnosis was analyzed.

RESULTS

A total number of 696 patients was included. The effect of every 10 µg/m³ increment of particulate matters with an aerodynamic diameter < 10 µm (PM₁₀) on total monthly APE cases (unprovoked PE and provoked PE) was increased significantly at lag 4, 5 and 6 months with adjusted RR (95% CI) of 1.06 (1.01, 1.12), p = 0.011, 1.07 (1.01, 1.13), p = 0.021 and 1.06 (1.01, 1.12), p = 0.030, respectively. Adjusted RR for APE was significantly increased for PM₁₀ in the second tertile ((adjusted RR (95% CI) 1.76 (1.12, 2.77)), p = 0.014.

CONCLUSIONS

We conclude that PM₁₀ is associated with an increased prevalence of APE cases. The policy for tighter control of air pollution in our country is needed to reduce the impact of air pollutants on people's health.

Obesity and contraceptive use: impact on cardiovascular risk

Obesity and oestrogen containing contraceptive products are well-known independent cardiovascular risk factors. However, a significant number of obese women continue to receive prescriptions of hormonal products that contain oestrogens for their contraception. We have conducted a narrative review to discuss the latest evidence, ongoing research, and controversial issues on the synergistic effect of obesity and contraceptive use, in terms of cardiovascular risk. There is compelling evidence of an interplay between obesity and contraception in increasing cardiovascular risk. Women who present both obesity and use of combined oral contraceptives (COCs) have a greater risk (between 12 and 24 times) to develop venous thromboembolism than non-obese non-COC users. Data here discussed offer new insights to increase clinicians' awareness on the cardiovascular risk in the clinical management of obese women. The synergistic effect of obesity and COCs on deep venous thrombosis risk must be considered when prescribing hormonal contraception. Progestin-only products are a safer alternative to COCs in patients with overweight or obesity. Obese women taking contraceptives should be viewed as an 'at risk' population, and as such, they should receive advice to change their lifestyle, avoiding other cardiovascular risk factors, as a form of primary prevention. This indication should be extended to young women, as data show that COCs should be avoided in obese women of any age.

Polygenic Risk Scores for Cardiovascular Disease: A Scientific Statement From the American Heart Association

Cardiovascular disease is the leading contributor to years lost due to disability or premature death among adults. Current efforts focus on risk prediction and risk factor mitigation' which have been recognized for the past half-century. However, despite advances, risk prediction remains imprecise with persistently high rates of incident cardiovascular disease. Genetic characterization has been proposed as an approach to enable earlier and potentially tailored prevention. Rare mendelian pathogenic variants predisposing to cardiometabolic conditions have long been known to contribute to disease risk in some families. However, twin and familial aggregation studies imply that diverse cardiovascular conditions are heritable in the general population. Significant technological and methodological advances since the Human Genome Project are facilitating population-based comprehensive genetic profiling at decreasing costs. Genome-wide association studies from such endeavors continue to elucidate causal mechanisms for cardiovascular diseases. Systematic cataloging for cardiovascular risk alleles also enabled the development of polygenic risk scores. Genetic profiling is becoming widespread in large-scale research, including in health care-associated biobanks, randomized controlled trials, and direct-to-consumer profiling in tens of millions of people. Thus, individuals and their physicians are increasingly presented with polygenic risk scores for cardiovascular conditions in clinical encounters. In this scientific statement, we review the contemporary science, clinical considerations, and future challenges for polygenic risk scores for cardiovascular diseases. We selected 5 cardiometabolic diseases (coronary artery disease, hypercholesterolemia, type 2 diabetes, atrial fibrillation, and venous thromboembolic disease) and response to drug therapy and offer provisional guidance to health care professionals, researchers, policymakers, and patients.

Occlusion of a Vortex Vein After Treatment With Half-Fluence Photodynamic Therapy Combined With Intravitreal Aflibercept Injection for Pachychoroid Neovasculopathy

Photodynamic therapy (PDT) is a treatment option for pachychoroid diseases such as central serous chorioretinopathy (CSC), pachychoroid neovasculopathy (PNV), polypoidal choroidal vasculopathy (PCV), and peripapillary pachychoroid syndrome (PPS). On the other hand, morphological changes of choroidal vessels in the irradiated field after PDT have also been discussed, with occlusion of choriocapillaris and stenosis of choroidal middle and large vessels being reported. Here, we report a case of vortex vein occlusion after half-fluence PDT (HF-PDT) combined with an anti-vascular endothelial growth factor (VEGF) agent for PNV. In this case, HF-PDT achieved complete occlusion of PNV; in addition, a vortex vein that flowed in PNV but was located outside the PDT irradiation field was fully occluded three months post-treatment. At the occluded site of the vortex vein, indocyanine green video angiography revealed pulsation downstream of the vortex vein. Such occlusion of a large vessel by HF-PDT has not been reported previously. Occlusion could be induced by two factors: the potentiality of PDT and risk factors for thromboembolism, such as older age, smoking, and arrhythmia. Further studies are required to determine the mechanisms of these large vessel occlusions.

Clinical epidemiology of venous thromboembolic disease: An institutional registry

Introduction

Venous thromboembolism (VTE) is a major health concern, with an annual incidence of ~1 in 1,000. The epidemiology of VTE in Saudi Arabia has not been adequately described yet. Therefore, this study aimed to assess the clinical characteristics, risk factors, diagnostic methods, management, and clinical outcomes of patients with VTE.

Methods

This study was based on a VTE registry created over ten years at King Fahad Medical City (KFMC) in Riyadh, Saudi Arabia. All adult inpatients and outpatients referred to the thrombosis unit of the KFMC with clinically suspected VTE including pulmonary embolism (PE) and deep vein thrombosis (DVT) were enrolled. Data were collected using a standardized case report form, which included demographic and clinical characteristics, risk factors, diagnostic methods, management, and outcomes.

Results

A total of 1,008 patients were recruited. Most patients were women (73.2%), and more than half of all patients had unprovoked VTE (58%). Among the provoked cases, the most frequent cause was surgery (29.8%), followed by hospitalization (24.2%). There was a significant statistical association between provoked status and sex, family history of VTE, smoking, recent hospitalization within 3 months for a medical condition, the site of VTE, and underlying peripheral vascular disease and varicose veins (all p &lt; 0.05). The majority (88.3%) of patients with deep vein thrombosis was hospitalized for ≤3 days (n = 433, 79.9%), while fewer than half of the patients with PE needed hospitalization (45.3%). Thrombolytic therapy was administered to 14.1% (n = 142) of patients, and catheter-directed thrombolysis was performed in 1.0% (n = 10) of patients. The odds of mortality for provoked VTE were 3.20 times higher than those of unprovoked VTE [2.12–4.83; p-value &lt; 0.001].

Conclusion

Unprovoked VTE was more common than provoked VTE in the Saudi Arabian cohort, implying hereditary predisposition. Furthermore, male sex, family history of VTE, prior history of VTE, type of VTE, underlying obesity, history of trauma, surgery, hospitalization, pregnancy, and 3–6 months of anticoagulation therapy were the most critical risk factors for VTE recurrence. The treatment patterns and clinical results were comparable to those reported in the literature.

Thrombophilia Impact on Treatment Decisions, Subsequent Venous or Arterial Thrombosis and Pregnancy-Related Morbidity: A Retrospective Single-Center Cohort Study

(1) Background: Thrombophilia testing utility has remained controversial since its clinical introduction, because data on its influence on treatment decisions are limited. (2) Methods: We conducted a single-center retrospective cohort study of 3550 unselected patients referred for thrombophilia consultation at the Bern University Hospital in Switzerland from January 2010 to October 2020. We studied the influence of thrombophilia testing results on treatment decisions and evaluated the association between thrombophilia and thromboembolic and pregnancy-related morbidity events after testing up to 03/2021. (3) Results: In 1192/3550 patients (34%), at least one case of thrombophilia was found and 366 (10%) had high-risk thrombophilia. A total of 211/3550 (6%) work-ups (111/826 (13%) with low-risk thrombophilia and 100/366 (27%) with high-risk thrombophilia) led to an appropriate decision to extend or initiate anticoagulation, and 189 (5%) negative results led to the withholding of anticoagulation therapy inappropriately. A total of 2492 patients (69%) were followed up for >30 days, with a median follow-up of 49 months (range, 1−183 months). Patients with high-risk thrombophilia had a higher risk of subsequent venous thromboembolic events and pregnancy-related morbidity compared to those without thrombophilia. (4) Conclusions: Our study demonstrated the limited usefulness of thrombophilia work-up in clinical decision-making. High-risk thrombophilia was associated with subsequent venous thromboembolism and pregnancy-related morbidity.

Blood Cells and Venous Thromboembolism Risk: A Two-Sample Mendelian Randomization Study

Background

Previous studies have shown that various cell indices are associated with a higher risk of venous thromboembolism (VTE), however, whether these findings reflect a causal relationship remains unclear. Therefore, we performed a two-sample Mendelian randomization (MR) analysis to assess the causal association of various blood cells with VTE risk.

Study Design and Methods

Summary statistics of genetic instruments representing cell indices for erythrocytes, leukocytes, and platelets were extracted from genome-wide association studies of European ancestry, by Two-Sample Mendelian Randomization. Inverse variance weighting (IVW) was used as the primary analytical method for MR. Sensitivity analyses were performed to detect horizontal pleiotropy and heterogeneity.

Results

Genetically predicted red blood cell distribution width, mean reticulocyte volume, and mean red blood cell volume were positively associated with VTE, with odds ratio (OR) of 1.002 [CI 1.000-1.003, P = 0.022), 1.003 (CI 1.001-1.004, P = 0.001, respectively)] and 1.001 (CI 1.000-1.002, P = 0.005). Genetically predicted monocyte count was negatively correlated with VTE, with OR = 0.998 (CI 0.996-0.999, P = 0.041).

Conclusion

Genetically liability to high- red blood cell distribution width, mean reticulocyte volume, mean red blood cell volume, and low monocyte count are associated with the higher risk of VTE. Targeting these factors might be a potential strategy to prevent VTE.

Severe compression of left iliac vein is a protective factor for the risk of inferior vena cava thrombosis

OBJECTIVE

The purpose of this study is to evaluate the association between left iliac vein (LIV) compression and inferior vena cava thrombosis (IVCT) in patients with LIV involvement of deep vein thrombosis (DVT).

METHODS

A total of 263 consecutive DVT patients were retrospectively reviewed and divided into group IVCT and non-IVCT. The influences of LIV smallest diameter and percentage compression on the risk of IVCT were investigated using logistic regression analysis.

RESULTS

The mean age of IVCT patients was significantly younger than that of non-IVCT patients (55.5±1.8 vs. 62.7±1.1, p=0.001). The percentage of provoked DVT in IVCT patients was higher than that in non-IVCT patients (67.1% vs 48.2%, p=0.01). The smallest diameter of LIV in ICVT patients was larger than that in non-IVCT patients (4.1±0.3 vs. 2.5±0.2, p<0.001). Mean percentage compression of LIV in IVCT patients was significantly lower than that in non-IVCT patients (63.5±2.2 vs. 74.3±1.3; P<0.001). Age was associated with decreased odds of ICVT (OR: 0.965, 95% CI: 0.965-0.985, P=0.001). Provoked DVT was associated with increased odds of ICVT (OR:2.011, 95% CI: 1.070-3.782, P=0.03). LIV compression was associated with decreased odds of ICVT for each 1mm decrease in smallest diameter of the LIV (OR, 0.717; 95% CI, 0.627-0.820; P <0.001), and for each 10% increase in percentage compression of the LIV (OR, 0.715; 95% CI, 0.612-0.835; P <0.001).

CONCLUSION

Among LIV involvement of DVT patients, non-IVCT patients had more severe LIV compression than IVCT patients. Severe LIV compression may be a protective factor for the risk of IVCT.

Association between self-rated health and venous thromboembolism in Malmö Preventive Program: A cohort study

INTRODUCTION

Venous thromboembolism (VTE) and cardiovascular disease (CVD) share some risk factors such as smoking, obesity, and dietary habits. Poor self-rated health (SRH) has been shown to be a predictor of arterial CVD and mortality for both men and women. The association between SRH and VTE has only been investigated in one previous Swedish study with a cohort that just contained women. This Swedish study did not show any significant associations between poor SRH and VTE in women.

METHODS

A cohort of 22,444 men and 10,902 women in the Malmö Preventive Program was followed for a period of 44 years. All participants in the baseline screening with measurements including SRH were traced in national registers. Data on VTE events were collected from national hospital registries. Cox proportional regression analysis was used to calculate the association between SRH and time to VTE.

RESULTS

During a follow-up time of 44.31 years, a total of 2612 individuals were affected by VTE. Good SRH was associated with a lower risk for VTE in women both in the univariate model (HR = 0.75, CI = 0.65-0.85) and after adjustments for age, smoking, BMI and varicose veins (HR = 0.81, CI 0.70-0.93). SRH was not a predictor for VTE in men, neither in the unadjusted (HR = 1.05, CI 0.90-1.13) nor in the fully adjusted model (HR = 1.00, CI = 0.88-1.14).

CONCLUSION

In this cohort study, SRH was associated with VTE in women but not among men. The association was significant even when adjusting for well-known risk factors such as varicose veins, BMI and smoking.

First Experience in Living Liver Donation From Donors With Sickle Cell Trait

Living donor liver transplantation is the main source of organs in the Middle East. Therefore, well balanced criteria are needed to avoid unnecessary exclusion of potential donors, while prioritizing donor safety. We face a high incidence of sickle cell trait (SCT; and disease). Therefore, there is vast experience in general and cardiac surgeries in SCT carriers at our center. After studying their management in detail, we considered accepting SCT carriers as living liver donors, on an exceptional basis. This the first single-center case series of living donor liver transplantation with SCT.

Modeling Time to Cure of Deep Vein Thrombosis Using Cox Proportional Model in Southwest of Ethiopia

Background

Globally, there are about 10 million cases of deep vein thrombosis every year, and it is the third leading cardiovascular disease after myocardial infarction and stroke. The objective of the study is to assess risk factors of time to cure patients of deep vein thrombosis in southwest Ethiopia.

Methods

A retrospective cohort study design was used. The study population was deep vein thrombosis patients at purposively selected hospitals in Southwest Ethiopia from January 2017 to December 2020. Cox proportional hazard model was used to identify risk factors associated with deep vein thrombosis.

Results

Out of the total 1068 registered as deep vein thrombosis patients, 263(24.6%) were cured during the study period, and 805(75.4%) were censored. Results of the Cox proportional hazard model show that; age, gender, family history of deep vein thrombosis, smoking status, immobilize and alcohol consumption were factors associated with deep vein thrombosis (p-value<0.05).

Conclusion

The patients with a family history of deep vein thrombosis, prolonged immobilization, greater the 50 years, smoking cigarettes, female (non-pregnant) and alcohol users had a longer curing time of deep vein thrombosis compared to others.

Proteomics in thrombosis research

A State of the Art lecture titled “Proteomics in Thrombosis Research” was presented at the ISTH Congress in 2021. In clinical practice, there is a need for improved plasma biomarker‐based tools for diagnosis and risk prediction of venous thromboembolism (VTE). Analysis of blood, to identify plasma proteins with potential utility for such tools, could enable an individualized approach to treatment and prevention. Technological advances to study the plasma proteome on a large scale allows broad screening for the identification of novel plasma biomarkers, both by targeted and nontargeted proteomics methods. However, assay limitations need to be considered when interpreting results, with orthogonal validation required before conclusions are drawn. Here, we review and provide perspectives on the application of affinity‐ and mass spectrometry‐based methods for the identification and analysis of plasma protein biomarkers, with potential application in the field of VTE. We also provide a future perspective on discovery strategies and emerging technologies for targeted proteomics in thrombosis research. Finally, we summarize relevant new data on this topic, presented during the 2021 ISTH Congress.

Disease activity as a risk factor for venous thromboembolism in rheumatoid arthritis analysed using time-averaged DAS28CRP: a nested case-control study

The objective of this study is to clarify the clinical features and risk factors of venous thromboembolism (VTE) in patients with rheumatoid arthritis (RA). We retrospectively reviewed the prevalence of VTE in RA patients who visited Hokkaido University Hospital from 2010 to 2019 and had more than 2 years of follow-up. To explore the risk to develop VTE, we selected 260 RA patients without VTE (non-VTE) via density sampling and identified the risk factors for VTE by multivariate logistic regression analysis. Univariate conditional logistic regression analysis showed older age (p < 0.0001, Odds Ratio [OR] 1.08, 95% Confidence Interval [CI] 1.04-1.14), increase of the body mass index (BMI) (p = 0.001, OR 1.17, 95% CI 1.06-1.31), higher prevalence of RA-associated lung disease (p = 0.002, OR 2.10, 95% CI 1.33-3.30) and more frequent glucocorticoid usage (p = 0.001, OR 2.09, 95% CI 1.34-3.51) in RA patients was associated with the development of VTE significantly. Furthermore, patients with higher time-averaged disease activity score 28 (DAS28) CRP were at elevated risk (p < 0.0001, OR 3.25, 95% CI 1.94-6.12). In conditional multivariate logistic regression analysis, time averaged DAS28CRP was significantly associated with the development of VTE (p = 0.0001, adjusted OR 3.40, 95% CI 1.77-7.85). Disease activity was identified as a major risk factor of VTE in patients with RA, suggesting that sustained clinical remission could be beneficial for decrease the risk of VTE.

Case Series of Thrombosis With Thrombocytopenia Syndrome After COVID-19 Vaccination-United States, December 2020 to August 2021

BACKGROUND

Thrombosis with thrombocytopenia syndrome (TTS) is a potentially life-threatening condition associated with adenoviral-vectored COVID-19 vaccination. It presents similarly to spontaneous heparin-induced thrombocytopenia. Twelve cases of cerebral venous sinus thrombosis after vaccination with the Ad26.COV2.S COVID-19 vaccine (Janssen/Johnson & Johnson) have previously been described.

OBJECTIVE

To describe surveillance data and reporting rates of all reported TTS cases after COVID-19 vaccination in the United States.

DESIGN

Case series.

SETTING

United States.

PATIENTS

Case patients receiving a COVID-19 vaccine from 14 December 2020 through 31 August 2021 with thrombocytopenia and thrombosis (excluding isolated ischemic stroke or myocardial infarction) reported to the Vaccine Adverse Event Reporting System. If thrombosis was only in an extremity vein or pulmonary embolism, a positive enzyme-linked immunosorbent assay for antiplatelet factor 4 antibodies or functional heparin-induced thrombocytopenia platelet test result was required.

MEASUREMENTS

Reporting rates (cases per million vaccine doses) and descriptive epidemiology.

RESULTS

A total of 57 TTS cases were confirmed after vaccination with Ad26.COV2.S (n = 54) or a messenger RNA (mRNA)-based COVID-19 vaccine (n = 3). Reporting rates for TTS were 3.83 per million vaccine doses (Ad26.COV2.S) and 0.00855 per million vaccine doses (mRNA-based COVID-19 vaccines). The median age of patients with TTS after Ad26.COV2.S vaccination was 44.5 years (range, 18 to 70 years), and 69% of patients were women. Of the TTS cases after mRNA-based COVID-19 vaccination, 2 occurred in men older than 50 years and 1 in a woman aged 50 to 59 years. All cases after Ad26.COV2.S vaccination involved hospitalization, including 36 (67%) with intensive care unit admission. Outcomes of hospitalizations after Ad26.COV2.S vaccination included death (15%), discharge to postacute care (17%), and discharge home (68%).

LIMITATIONS

Underreporting and incomplete case follow-up.

CONCLUSION

Thrombosis with thrombocytopenia syndrome is a rare but serious adverse event associated with Ad26.COV2.S vaccination. The different demographic characteristics of the 3 cases reported after mRNA-based COVID-19 vaccines and the much lower reporting rate suggest that these cases represent a background rate.

PRIMARY FUNDING SOURCE

Centers for Disease Control and Prevention.

High Prevalence of Plasminogen Activator Inhibitor-1 4G/5G Polymorphism among Patients with Venous Thromboembolism in Kerala, India

Venous thromboembolism (VTE) is a multifactorial clotting disorder in which inherited and environmental factors synergistically contribute to its pathogenesis. The aim of this case-control study was to analyze the prevalence of hereditary thrombophilic risk factors, provoking and non-provoking environmental risk factors in patients with VTE from Kerala, India. We have observed a low prevalence of factor V Leiden (7%), prothrombin G20210A (2%), and prothrombin G20030A (2%) mutations and a high prevalence of plasminogen activator inhibitor-1 (PAI-1) 4G/5G (52%), PAI-1 4G/4G (24%) genotypes in the VTE patients (n = 147). Deficiency of anticoagulants, antithrombin (3.4%), and protein C (4.1%) was relatively low. None of the risk factors were observed in 17% of the patients. Majority of VTE patients were younger than 50 years with a median age of 43 years. In conclusion, our results indicate a high prevalence of PAI-1 4G/5G polymorphism among the VTE patients which is in concordance with previous studies in the Asian population. The PAI-1 4G/5G polymorphism could be a potential biomarker for assessing VTE risk, particularly among the Indian population.