Acute infection as a trigger for incident venous thromboembolism: Results from a population-based case-crossover study

Risk factors and mortality associated with venous thromboembolism in the elderly US population with chronic lymphocytic leukemia

BACKGROUND

Venous thromboembolism (VTE) causes morbidity and mortality in cancer patients. The association of VTE with known risk factors in chronic lymphocytic leukemia (CLL) is not known.

OBJECTIVE

To examine risk factors and mortality associated with VTE in White, Black, and Asian CLL patients.

METHODS

The United States SEER-Medicare database (2000-2015) was used for CLL patients ≥ 65 years. Logistic regression was used to examine VTE risk factors and Cox proportional regression was used to evaluate the effect of VTE on mortality in White, Black, and Asian CLL patients.

RESULTS

Among 34,075 CLL patients, VTE was diagnosed in 11.6 % of 31,395 White, 14.6 % of 2062 Black and 6.3 % of 618 Asian patients. Risk of having VTE was, ORa = 1.2 (95 % CI, 1.0-1.4) for Black patients and ORa = 0.5 (95 % CI, 0.4-0.7) for Asian patients compared to White patients. Anemia and heart failure were associated with VTE in all three racial cohorts and were the only risk factors in Asian patients. Other risk factors in White patients were the same as in the overall population, including hypertension, obesity, COPD, kidney disease, diabetes, hyperlipidemia, myocardial infarction, and chemotherapy. In Black patients, other risk factors were hypertension, and chemotherapy. Mortality was slightly higher with VTE in the overall population and in White patients.

CONCLUSION

There was difference in VTE risk factors in White, Black, and Asian patients. VTE was marginally associated with mortality in CLL patients. Our findings may help to identify patients at higher risk of VTE in racially diverse CLL populations.

Dispensed prescription medications and short-term risk of pulmonary embolism in Norway and Sweden

Scandinavian electronic health-care registers provide a unique setting to investigate potential unidentified side effects of drugs. We analysed the association between prescription drugs dispensed in Norway and Sweden and the short-term risk of developing pulmonary embolism. A total of 12,104 pulmonary embolism cases were identified from patient- and cause-of-death registries in Norway (2004-2014) and 36,088 in Sweden (2005-2014). A case-crossover design was used to compare individual drugs dispensed 1-30 days before the date of pulmonary embolism diagnosis with dispensation in a 61-90 day time-window, while controlling for the receipt of other drugs. A BOLASSO approach was used to select drugs that were associated with short-term risk of pulmonary embolism. Thirty-eight drugs were associated with pulmonary embolism in the combined analysis of the Norwegian and Swedish data. Drugs associated with increased risk of pulmonary embolism included certain proton-pump inhibitors, antibiotics, antithrombotics, vasodilators, furosemide, anti-varicose medications, corticosteroids, immunostimulants (pegfilgrastim), opioids, analgesics, anxiolytics, antidepressants, antiprotozoals, and drugs for cough and colds. Mineral supplements, hydrochlorothiazide and potassium-sparing agents, beta-blockers, angiotensin 2 receptor blockers, statins, and methotrexate were associated with lower risk. Most associations persisted, and several additional drugs were associated, with pulmonary embolism when using a longer time window of 90 days instead of 30 days. These results provide exploratory, pharmacopeia-wide evidence of medications that may increase or decrease the risk of pulmonary embolism. Some of these findings were expected based on the drugs' indications, while others are novel and require further study as potentially modifiable precipitants of pulmonary embolism.

Postoperative venous thromboembolism risk in patients with vulvar carcinoma: An analysis of the National surgical Quality Improvement Program (NSQIP) database

Objectives

Due to low incidence of vulvar cancer (VC), incidence and predictors for development of venous thromboembolism (VTE) are poorly understood. We examined incidence and risk factors associated with VTE in patients undergoing surgery for VC.

Methods

We included patients who underwent surgery for VC from the National Surgical Quality Improvement Program database. VTE within the 30-day postoperative period was captured with Current Procedural Terminology codes. Baseline demographics and clinical characteristics were compared between patients with and without VTE. Univariable and multivariable-adjusted exact logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between risk factors and VTE.

Results

We identified 1414 patients undergoing procedures for VC from the NSQIP database. Overall, 11 (0.8 %) patients developed VTE. Univariable predictors of VTE included surgery type [compared with simple vulvectomy: radical vulvectomy only (OR = 7.97, 95 % CI = 1.44, infinity) and radical vulvectomy plus unilateral IFN (OR = 15.98, 95 % CI = 2.70, infinity)], unplanned readmission (OR = 11.56, 95 % CI = 2.74, 46.38), deep surgical site infection (OR = 16.05, 95 % CI = 1.59-85.50), and preoperative thrombocytosis (OR = 6.53, 95 % CI = 0.00, 34.86). In a multivariable-adjusted model, longer operative time (≥72 min OR = 11.33, 95 % CI = 1.58-499.03) and preoperative functional status [compared with complete independence: total dependence (OR = 53.88, 95 % CI = 0.85, infinity) and partial dependence (OR = 53.88, 95 % CI = 0.85, infinity)] were associated with VTE.

Conclusion

In this cohort of patients with VC undergoing radical vulvectomy, VTE incidence was low. Surgery type, longer operative time, dependent functional status, and wound disruption were identified as risk factors. Our findings highlight opportunities for prophylactic intervention in certain patients.

Risk factors for suspected pulmonary embolism in children: Complication of Mycoplasma pneumoniae pneumonia

PURPOSE

Pulmonary embolism (PE) is not a rare complication of Mycoplasma pneumoniae pneumonia (MPP) in children. We sought to determine the incidence of PE in children with MPP who underwent clinically indicated CT pulmonary angiography (CTPA) and to evaluate the risk factors for PE.

METHODS

All 106 children with MPP who were clinically suspected of having PE and who underwent CTPA were retrospectively enrolled from June 2018 to December 2021. The clinical features, laboratory data, and radiological parameters were recorded (e.g., lung consolidation involved and the Qanadli score). A Cox proportional hazards model and area under the receiver operating characteristic (ROC) curve were used to evaluate the risk factors and prognostic discriminatory capacity for PE.

RESULTS

PE was detected in 26 of 106 (24.5 %) children (mean age, 6.2 years ± 3.3 years; 53 boys). Sixteen of the 26 (61.5 %) children with PE were boys. The mean age of the children with PE was 8.1 ± 2.9 years, and the mean Qanadli score was 15.3 ± 10.2. Children with PE had higher D-dimer levels (9.3 ± 7.1 mg/Lvs. 3.6 ± 3.8 mg/L) and a greater frequency of lung lobe consolidation (25 (96.2 %) vs. 64 (80.0 %)) (all P < 0.05). For children with MPP, age (hazard ratio (HR) = 1.96 (95 % CI1.04, 3.71; P = 0.037), D-dimer level (HR = 1.52, 95 % CI: 1.03, 2.24; P = 0.029), and bilateral lung consolidation (HR = 2.41, 95 % CI: 1.03, 5.58; P = 0.043) were found to be independent predictors of PE.

CONCLUSION

Clinical and CT radiological predictors could be used to predict PE in children with MPP. The use of risk factor assessment as a tool has the potential to guide more appropriate use of CTPA in children.

Sex-specific differences in the clinical profile among psychiatric patients with pulmonary Embolism: a hospital-based retrospective study

BACKGROUND

Pulmonary embolism (PE) is a severe and life-threatening complication of venous thromboembolism. However, there is a lack of systematic studies on differences between female and male PE patients. This paper aimed to compare the sex-specific differences in clinical characteristics and laboratory indicators in psychotic patients with PE.

METHODS

This retrospective study enrolled psychiatric patients with PE from June 2018 to June 2022 at Shenzhen Kangning Hospital (Shenzhen Mental Health Center). Demographic characteristics, factors associated with PE, and laboratory indices were collected to assess sex-specific differences.

RESULTS

Of the 168 patients, 87 (51.8%) were female and 81 (48.2%) were male, with a mean age of 58 years for females and 46 years for male patients. The male group had higher ratio of hyperprolactinemia, more patients using antipsychotic medications, higher D-dimer levels at PE onset, greater D-dimer difference, and a higher rate of D-dimer elevation than the female group (p < 0.05). Female patients were significantly older, exhibited a higher prevalence of diabetes, and had a greater number of patients taking antidepressants and hypnotics/sedatives than male patients (p < 0.05). Schizophrenia spectrum disorders were more prevalent in male patients, while female patients had a higher incidence of mood disorders (p < 0.05). Among patients aged < 45 years, the male group had higher D-dimer levels at PE onset and greater D-dimer difference (p < 0.05). Among all 112 patients aged ≥ 45 years, male patients were more likely than female patients to have respiratory tract infections, higher D-dimer levels at PE onset, greater D-dimer difference, and a higher rate of D-dimer elevation (p < 0.05). The multiple linear regression analysis indicated that hyperprolactinemia and the use of first-generation antipsychotics (FGAs) were associated with D-dimer levels at PE onset in male patients, while the time of PE onset and protective restraints were associated with D-dimer levels at PE onset in female patients (p < 0.05).

CONCLUSION

PE-associated clinical features differ between male and female patients. These differences may imply that the processes and mechanisms of PE onset are sex specific. Male patients are more likely to have respiratory tract infections and higher D-dimer levels at PE onset than female patients. The use of FGAs may be associated with increased D-dimer in male psychiatric patients, while protective restraints may be associated with increased D-dimer in female psychiatric patients.

Primary prevention of venous thromboembolism with low molecular weight heparins in surgical patients – 2024: Council of Experts resolution

On March 15, 2024, in Moscow, the Russian Phlebological Association and the National Association of Specialists in Thrombosis, Clinical Hemostasiology and Hemorheology organized a meeting of the Council of Experts during the Russian Forum on Thrombosis and Hemostasis on the acute issues of venous thromboembolism (VTE) primary prevention using low molecular weight heparins (LMWH) in surgical patients with different body weight. The participants reviewed the relevance and prevalence of this problem in surgical practice, discussed risk factors and the frequency of VTE development, including bleeding in the postoperative period, and the Caprini risk score for complications. The discussion also focused on standard and personalized LMWH doses for primary prophylaxis of VTE in the perioperative period in surgical patients, depending on body weight, and the role of laboratory tests, including assessment of LMWH anti-Xa activity for monitoring the efficacy and safety of VTE primary prevention in clinical practice.

Association of Symptomatic Venous Thromboembolism and BMI in Patients Undergoing Sports Medicine Knee Procedures: A Retrospective Case-Control Study

BACKGROUND

The purpose of this study was to characterize the prevalence of venous thromboembolism (VTE; including deep vein thrombosis [DVT] and pulmonary embolism [PE]) after sports medicine knee procedures by a single surgeon at an academic institution, identify factors associated with increased risk of VTE, and determine risk factor thresholds for beyond which VTE risk is elevated.

HYPOTHESIS

We hypothesized that the prevalence of VTE after sports medicine knee procedures is low, but that increasing weight and body mass index (BMI) would be associated with elevated risk.

STUDY DESIGN

Retrospective case-control study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A retrospective case-control study analyzing sports medicine knee surgeries from 2017 to 2020 was conducted using current procedural terminology codes to identify cases. Optimal cutoff points for specific continuous patient characteristics were calculated to determine elevated risk of postoperative VTE. Overall VTE-free survival was assessed using Kaplan-Meier analysis and Cox proportional hazard regression models.

RESULTS

Among the 724 eligible patients, there were 13 postoperative VTE events (1.79% prevalence; 12 DVTs, 1 DVT/PE). Increasing weight and BMI were significant risk factors for postoperative VTE (P = 0.03 and P = 0.04, respectively), with weight >94.7 kg and BMI >27.9 kg/m2 associated with elevated risk in male patients and weight >79.1 kg and BMI >28.1 kg/m2 associated with elevated risk for female patients. Cox regression demonstrated a significantly increased risk of postoperative VTE for male patients with BMI ≥27.9 kg/m2.

CONCLUSION

Patients who undergo sports medicine knee surgery with increased weight and BMI are at an elevated risk of postoperative VTE. An individualized approach should be considered for chemoprophylaxis in patients with these risk factors.

CLINICAL RELEVANCE

Consider chemoprophylaxis in patients with increased weight and BMI who undergo sports medicine knee surgery since they are at an elevated risk of postoperative VTE.

Comorbidity of patients with noncommunicable diseases in general practice. Eurasian guidelines

Создание руководства поддержано Советом по терапевтическим наукам отделения клинической медицины Российской академии наук.

Real-world comparative effectiveness of dalteparin and enoxaparin for venous thromboembolism prophylaxis

Venous thromboembolism (VTE) is a preventable cause of significant morbidity and mortality in hospitalized patients world-wide. In Australia, the low-molecular weight heparins (LMWHs) enoxaparin or dalteparin are usually used as first-line prophylaxis for VTE, though there is uncertainty whether dalteparin has the same effectiveness as enoxaparin in real-world settings. This is relevant because dalteparin is less renally cleared and may be more cost effective than enoxaparin. The aim of this study was to explore VTE event incidence in a general cohort of hospitalized adult inpatients who were prescribed enoxaparin or dalteparin for VTE prophylaxis. A retrospective observational study was conducted at a quaternary hospital in Brisbane, Australia, of patients who had experienced a hospital-acquired VTE from 1 September 2021 to 1 March 2023. Patients were identified from routinely collected data following an in-hospital VTE event, and further data was retrieved retrospectively from the integrated electronic Medical Record (ieMR). Incidence and type of VTE events, LMWH-prescribing patterns, and risk factors were assessed. The incidence of VTE events were similar across the dalteparin and enoxaparin cohorts (42.1 events/10 000 patients vs. 34.4 events/10 000 patients, respectively), although patients prescribed enoxaparin had a higher number of risk factors, particularly obesity and active cancer. Our research indicates comparable incidence of VTE in patients prescribed dalteparin compared with enoxaparin in an Australian hospital general cohort of adult inpatients. Dalteparin may be as effective as enoxaparin for VTE prophylaxis in a real-world cohort of patients, and as such dalteparin may be considered a suitable alternative to enoxaparin for VTE prophylaxis. Further research including large randomized controlled trials are required to confirm these results.

Blunt Cerebrovascular Injury Complications in Aging Adults: A National Trauma Database Study

INTRODUCTION

Blunt cerebrovascular injury (BCVI) is defined as a nonpenetrating injury to the carotid or vertebral arteries which can be highly morbid. Because BCVI is rare, most studies have been devoted to triaging trauma patients for BCVI identification, with little data available regarding the complications these patients experience after initial evaluation. Here, we analyze the association of complications during admission for BCVI patients.

METHODS

The National Trauma Databank was queried from 2007 to 2014 for adults ≥65 y old. Demographics, incidence of BCVI, and injury data were evaluated using univariate analysis. Rates of inpatient complications due to acutely acquired infections and strokes were evaluated using univariate and multivariable analysis.

RESULTS

We identified 666,815 non-BCVI and 552 BCVI patients. Patients with a BCVI were typically male, White, younger (65-75-y-old), had three or more comorbidities, and had Medicare insurance. BCVI patients had a mild head injury upon arrival at the emergency department and experienced a motor vehicle accident/fall. The median length of stay in the intensive care unit, days spent on a ventilator, and presence of polytrauma were higher among BCVI patients. BCVI patients had increased odds of experiencing a stroke and pneumonia as complications while admitted compared to their non-BCVI counterparts.

CONCLUSIONS

Postinjury, patients who suffered a BCVI had higher odds of stroke and pneumonia than patients who did not experience a BCVI. Additional studies are needed to determine the modifiable risk factors associated with BCVIs among aging adults.

Clinical experience with a chlorhexidine-coated PICC: A prospective, multicenter, observational study

INTRODUCTION

This study evaluated a chlorhexidine-coated peripherally inserted central catheter (PICC) and the incidence of associated complications within both inpatient and outpatient populations.

METHODS

This IRB-approved, multicenter, prospective observational study was performed at three large teaching hospitals in the US. All adults who required a PICC for ⩾14 days were considered. Patients were monitored throughout entire catheter dwell. Duplex venous ultrasounds were performed before insertion, after 10 to 14 days of dwell time, and upon removal. Data was collected from the hospital, outpatient clinic, and patient PICC diary records.

RESULTS

A total of 103 patients, 56% male, with mean BMI 29 ± 8.8, were enrolled. The majority (79%) of patients were from high-risk groups-cancer, infectious diseases, transplant, and trauma. Primary treatment indications were antibiotics (66.99%) and chemotherapy (25.24%). Double lumen PICCs (59.2%) were favored clinically, as was basilic vein placement (71.84%). Mean catheter dwell was 47.01 ± 25.82 days. Three (3, 2.9%) central line-associated bloodstream infections (CLABSI) were reported. Four patients (4.6%) reported symptomatic catheter-related thrombosis (CRT), confirmed with ultrasound. Three patients (3.4%) had ultrasound-confirmed fibroblastic sleeve (FS). Eight patients (9.2%) who entered the study with pre-existing superficial thrombosis, had complete resolution at the time of catheter removal. The incidence of CLABSI was 0.82/1000 days. The combined CRT and FS rate was 6.9%.

CONCLUSION

Based upon the observational findings of this study, chlorhexidine-coated PICC technology may be considered for use in patient populations who are at moderate to high-risk for catheter-related complications in both inpatient and outpatient settings.

Development and validation of a nomogram model for central venous access device-related thrombosis in hospitalized children

This study aimed to develop and validate a nomogram model of central venous access device-related thrombosis (CRT) for hospitalized children. A total of 503 consecutive cases from a hospital in Changsha City, Hunan Province were stochastically classified into the training set and internal validation set at a ratio of 7:3, and 85 consecutive cases in two hospitals in Urumqi City, Xinjiang Uygur Autonomous Region were collected as an external validation set. Univariate analysis and multivariate analysis on CRT-related risk factors of hospitalized children were conducted, a logistic regression model was employed to establish the nomogram, and the discrimination, calibration, and decision curve analysis was performed to assess the proposed nomogram model. The nomogram model involved seven independent risk factors, including blind catheterization, abnormal liver function, central line-associated bloodstream infection, infection, number of catheter lines, leukemia, and bed rest > 72 h. The discrimination results showed that the area under the receiver operating characteristic curve of the training set, internal validation set, and external validation set was 0.74, 0.71, and 0.76 respectively, and the accuracy rates of the proposed nomogram model were 79%, 72%, and 71% in the training set, internal validation set, and external validation set. The calibration results also showed that the calibration curve had great fitness for each dataset. More importantly, the decision curve suggested that the proposed nomogram model had a prominent clinical significance.

CONCLUSION

The nomogram model can be used as a risk assessment tool to reduce the missed diagnosis rate and the incidence of CRT in hospitalized children.

WHAT IS KNOWN

• Central venous access device-related thrombosis is generally asymptomatic for hospitalized children, causing the missed diagnosis of central venous access device-related thrombosis easily. • No risk prediction nomogram model for central venous access device-related thrombosis in hospitalized children has been established.

WHAT IS NEW

• A visual and personalized nomogram model was built by seven accessible variables (blind catheterization, abnormal liver function, central line-associated bloodstream infection, infection, number of catheter lines, leukemia, and bed rest > 72 h). • The model can effectively predict the risk of central venous access device-related thrombosis for hospitalized children.

Inflammasome Signaling, Thromboinflammation, and Venous Thromboembolism

Venous thromboembolism (VTE) remains a major health burden despite anticoagulation advances, suggesting incomplete management of pathogenic mechanisms. The NLRP3 (NACHT-, LRR- and pyrin domain-containing protein 3) inflammasome, interleukin (IL)-1, and pyroptosis are emerging contributors to the inflammatory pathogenesis of VTE. Inflammasome pathway activation occurs in patients with VTE. In preclinical models, inflammasome signaling blockade reduces venous thrombogenesis and vascular injury, suggesting that this therapeutic approach may potentially maximize anticoagulation benefits, protecting from VTE occurrence, recurrence, and ensuing post-thrombotic syndrome. The nonselective NLRP3 inhibitor colchicine and the anti-IL-1β agent canakinumab reduce atherothrombosis without increasing bleeding. Rosuvastatin reduces primary venous thrombotic events at least in part through lipid-lowering independent mechanisms, paving the way to targeted anti-inflammatory strategies in VTE. This review outlines recent preclinical and clinical evidence supporting a role for inflammasome pathway activation in venous thrombosis, and discusses the, yet unexplored, therapeutic potential of modulating inflammasome signaling to prevent and manage VTE.

Surgery As a Trigger for Incident Venous Thromboembolism: Results from a Population-Based Case-Crossover Study

Background  Surgery is a major transient risk factor for venous thromboembolism (VTE). However, the impact of major surgery as a VTE trigger has been scarcely investigated using a case-crossover design. Aim  To investigate the role of major surgery as a trigger for incident VTE in a population-based case-crossover study while adjusting for other concomitant VTE triggers. Methods  We conducted a case-crossover study with 531 cancer-free VTE cases derived from the Tromsø Study cohort. Triggers were registered during the 90 days before a VTE event (hazard period) and in four preceding 90-day control periods. Conditional logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for VTE according to major surgery and after adjustment for other VTE triggers. Results  Surgery was registered in 85 of the 531 (16.0%) hazard periods and in 38 of the 2,124 (1.8%) control periods, yielding an OR for VTE of 11.40 (95% CI: 7.42-17.51). The OR decreased to 4.10 (95% CI: 2.40-6.94) after adjustment for immobilization and infection and was further attenuated to 3.31 (95% CI: 1.83-5.96) when additionally adjusted for trauma, blood transfusion, and central venous catheter. In a mediation analysis, 51.4% (95% CI: 35.5-79.7%) of the effect of surgery on VTE risk could be mediated through immobilization and infection. Conclusions  Major surgery was a trigger for VTE, but the association between surgery and VTE risk was in part explained by other VTE triggers often coexisting with surgery, particularly immobilization and infection.

Thrombosis and thromboembolism: Brighton collaboration case definition and guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration case definition of thrombosis and thromboembolism to be used in the evaluation of adverse events following immunization, and for epidemiologic studies for the assessment of background incidence or hypothesis testing. The case definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of SARS-CoV-2 vaccines. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected expert reviewers prior to submission.

Predictors of venous thromboembolism in COVID-19 patients: results of the COVID-19 Brazilian Registry

Previous studies that assessed risk factors for venous thromboembolism (VTE) in COVID-19 patients have shown inconsistent results. Our aim was to investigate VTE predictors by both logistic regression (LR) and machine learning (ML) approaches, due to their potential complementarity. This cohort study of a large Brazilian COVID-19 Registry included 4120 COVID-19 adult patients from 16 hospitals. Symptomatic VTE was confirmed by objective imaging. LR analysis, tree-based boosting, and bagging were used to investigate the association of variables upon hospital presentation with VTE. Among 4,120 patients (55.5% men, 39.3% critical patients), VTE was confirmed in 6.7%. In multivariate LR analysis, obesity (OR 1.50, 95% CI 1.11-2.02); being an ex-smoker (OR 1.44, 95% CI 1.03-2.01); surgery ≤ 90 days (OR 2.20, 95% CI 1.14-4.23); axillary temperature (OR 1.41, 95% CI 1.22-1.63); D-dimer ≥ 4 times above the upper limit of reference value (OR 2.16, 95% CI 1.26-3.67), lactate (OR 1.10, 95% CI 1.02-1.19), C-reactive protein levels (CRP, OR 1.09, 95% CI 1.01-1.18); and neutrophil count (OR 1.04, 95% CI 1.005-1.075) were independent predictors of VTE. Atrial fibrillation, peripheral oxygen saturation/inspired oxygen fraction (SF) ratio and prophylactic use of anticoagulants were protective. Temperature at admission, SF ratio, neutrophil count, D-dimer, CRP and lactate levels were also identified as predictors by ML methods. By using ML and LR analyses, we showed that D-dimer, axillary temperature, neutrophil count, CRP and lactate levels are risk factors for VTE in COVID-19 patients.

Venous thromboembolism in critically ill patients with pneumonia in the pre-COVID-19 era: Data from a large public database

Background

The magnitude of venous thromboembolism (VTE) risk in severe COVID-19 is a matter of debate because of study heterogeneity, changes in VTE management, and scarce evidence of VTE risk in critically ill patients with pneumonia in the pre-COVID-19 era.

Objectives

To evaluate VTE risk in the pre-COVID-19 era in a large intensive care unit (ICU) database.

Patients/Methods

Data from consecutive pneumonia patients admitted to the ICU were retrieved from the Medical Information Mart for Intensive Care III. VTE risk was described in the entire cohort and in subgroups.

Results

Among 6842 pneumonia patients admitted to the ICU, 486 patients were diagnosed with VTE after a median of 3 (IQR 1-11) days in the ICU. The 30-day cumulative incidence of VTE was 7% and remained at this level across different age groups, sex, and type of ICU. After adjusting for death, the overall cumulative incidence of VTE was 5%. A total of 1788 patients received thromboprophylaxis (of 2958 for whom that data were available). VTE occurred in 10.7% (95% CI 9.0-12.6) of patients without thromboprophylaxis and in 6.4% (95% CI 5.4-7.6) of those with thromboprophylaxis. Mortality was 20.6% among patients with VTE and 19.2% among those without VTE.

Conclusions

In the pre-COVID-19 era, VTE risk in ICU patients with pneumonia was high and decreased with thromboprophylaxis. These findings can serve as comparators for future studies aiming at evaluating the impact of COVID-19 or other emerging infections on VTE risk.

Association between age and incidence of deep vein thrombosis in patients with spinal cord injury: an observational cross-sectional study

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To elucidate the association between age and incidence of deep vein thrombosis (DVT) in patients with spinal cord injury (SCI).

SETTING

Rehabilitation Medicine Department of the First Affiliated Hospital of China University of Science and Technology.

METHODS

Patients from August 2018 to December 2020 with SCI (N = 260) were tertiles divided the age into three groups to analyze the association between age and incidence of DVT.

RESULTS

American Spinal Cord Injury Association impairment scale (AIS), urinary tract infection (UTI), pulmonary infection (PI), and anticoagulation therapy (AT) were confounders for the association between age and incidence of DVT. The incidence of DVT increased by 1.07-fold (Non-adjusted model, OR = 1.07, P < 0.001), 1.05-fold (Minimally-adjusted model: adjusted for confounders, OR = 1.05, P = 0.010) and 1.06-fold [Fully-adjusted model: adjusted for confounders and unbalanced probable variables: AIS, UTI, PI, AT, Sex, D-dimer(new), Fibrinogen (new), Modes of injury and Level of injury, OR = 1.06, P = 0.012] when age increased by 1 year. The incidence of DVT had an increasing trend with age in different age tertile in the three models (P for trend <0.05). Age had a linearly association with incidence of DVT (OR = 1.07, P = 0.065) and stable in different subgroups, for lower age, the association was also linearly (OR = 4.40, P = 1.000), for middle (fold point = 46.46, P < 0.001) and higher age (fold point = 66, P = 0.017), the association was curvilinear.

CONCLUSION

Age had a linearly association with incidence of DVT. Quitting smoking, preventing/treating UTI and AT should be adopted in advance for patients with SCI for all age, especially for older.

Magnitudes of Risk Factors of Venous Thromboembolism and Quality of Anticoagulant Therapy in Ethiopia: A Systematic Review

Background

Venous thromboembolism is one of the major public health problems in the world. Though several studies were conducted to estimate common risk factors of venous thromboembolism and quality of anticoagulant therapy in Ethiopia, it is difficult to estimate the overall burdens of risk factors and quality of anticoagulant use because of the lack of a nationwide study.

Objective

To assess magnitudes of risk factors of venous thromboembolism and quality of anticoagulant therapy in Ethiopia.

Materials and Methods

Electronic searching using PubMed, EMBASE, Science Direct, Cochrane Database, Scopus, Hinari, Sci-Hub, African Journals Online Library, and Free-text Web Searches using Google Scholar was conducted from September, 15 to October 27, 2021. Each of the original studies was identified by Mesh terms and Boolean search technique using full title, various keywords and was assessed using the Joanna Briggs Institute Critical Appraisal Checklist. The data were extracted using a format prepared in Microsoft Excel and exported to STATA 14.0 for the outcome analyses.

Results

The database search delivered a total of 2118 studies. After articles were removed by duplications, titles, reading the abstract, and assessed for eligibility criteria, 12 articles were found suitable for the systematic review. Prolonged immobilization (41.30%) was the most commonly observed risk factor of venous thrombosis followed by acute infection (40.25%). The proportion of therapeutic range (INR = 2-3), sub-therapeutic range (INR <2), and supra-therapeutic range (INR >3) were 32.15%, 47.58%, and 17.62%, respectively. One hundred and thirty-eight patients (11.4%) have developed minor or major bleeding complications.

Conclusion

Prolonged immobilization and acute infection were the main risk factors for venous thromboembolism. The quality of anticoagulant therapy in Ethiopia was poor and bleeding complications were high. A strong effort is needed to improve the quality of anticoagulation and close monitoring of patients' international normalized ratio is required to improve treatment outcomes.

Increased Association of Pulmonary Thromboembolism and Tuberculosis during COVID-19 Pandemic: Data from an Italian Infectious Disease Referral Hospital

Pulmonary thromboembolism (PTE) has been associated with tuberculosis (TB), but the true incidence is unknown. The aim of our study was to retrospectively evaluate the PTE prevalence in TB patients hospitalized at the National Institute for Infectious Diseases L. Spallanzani during the January 2016–December 2021 period. Retrospective data collection and evaluation were conducted. Among 1801 TB patients, 29 (1.61%) exhibited PTE. Twenty (69%) had comorbidities; eleven (37.9%) had predisposing factors for PTE. Nineteen (65.5%) had extensive TB disease. The commonest respiratory symptoms were cough (37.9%), dyspnea (31%), chest pain (10.3%), and hemoptysis (6.9%). Twenty-five (86.2%) had elevated serum D-dimer levels. An increased prevalence of PTE from 0.6% in the pre-COVID-19 pandemic period to 4.6% in the pandemic period was found. Acute respiratory failure and extensive TB disease increased significantly in the pandemic period. The increase in PTE could be explained by the increased severity of TB in patients in the pandemic period and by increased clinical suspicion and, consequently, increased requests for D-dimer testing, including in patients with non-COVID-19 pneumonia. Patients with extensive pulmonary disease are at high risk of developing PTE. Clinicians should be aware of this potentially life-threatening complication of TB, and patients should receive a thromboembolism risk assessment.

Are Reduced Levels of Coagulation Proteins Upon Admission Linked to COVID-19 Severity and Mortality?

Background: The link between coagulation system disorders and COVID-19 has not yet been fully elucidated.

Aim: Evaluating the association of non-previously reported coagulation proteins with COVID-19 severity and mortality.

Design: Cross-sectional study of 134 COVID-19 patients recruited at admission and classified according to the highest COVID-19 severity reached (asymptomatic/mild, moderate, or severe) and 16 healthy control individuals.

Methods: Coagulation proteins levels (antithrombin, prothrombin, factor_XI, factor_XII, and factor_XIII) and CRP were measured in plasma by the ProcartaPlex Panel (Invitrogen) multiplex immunoassay upon diagnosis.

Results: We found higher levels of antithrombin, prothrombin, factor XI, factor XII, and factor XIII in asymptomatic/mild and moderate COVID-19 patients compared to healthy individuals. Interestingly, decreased levels of antithrombin and factors XI, XII, and XIII were observed in those patients who eventually developed severe illness. Additionally, survival models showed us that patients with lower levels of these coagulation proteins had an increased risk of death.

Conclusion: COVID-19 provokes early increments of some specific coagulation proteins in most patients. However, lower levels of these proteins at diagnosis might “paradoxically” imply a higher risk of progression to severe disease and COVID-19-related mortality.

Hypercoagulation in COPD: the clot thickens

There is a growing body of evidence that hypercoagulability is present in stable COPD, involves changes in multiple coagulation factors, and is not simply associated with major causes of inflammation and thrombosis https://bit.ly/3F5NnfN.

Risk Factors for Catheter-Related Thrombosis in Multiple Myeloma Patients Undergoing Autologous Stem Cell Transplantation

Background and Objectives: Cancer associated thrombosis (CAT) is a common complication of neoplasms. Multiple myeloma (MM) carries one of the highest risks of CAT, especially in the early phases of treatment. Autologous stem cell transplantation (ASCT) as the standard of care in transplant-eligible patients with MM carries a risk of catheter-related thrombosis (CRT). The aim of this study was identification of the risk factors of CRT in MM patients undergoing ASCT in 2009–2019. Materials and Methods: We retrospectively analyzed patients with MM undergoing ASCT. Each patient had central venous catheter (CVC) insertion before the procedure. The clinical symptoms of CRT (edema, redness, pain in the CVC insertion area) were confirmed with Doppler ultrasound examination. We examined the impacts of four groups of factors on CRT development: (1) patient-related: age, gender, Body Mass Index (BMI), obesity, Charlson comorbidity index, hematopoietic stem cell transplantation comorbidity index, renal insufficiency, and previous thrombotic history; (2) disease-related: monoclonal protein type, stage of the disease according to Salmon–Durie and International Staging System, number of prior therapy lines, and MM response before ASCT; (3) treatment-related: melphalan dose, transplant-related complications, and duration of post-ASCT neutropenia; (4) CVC-related: location, time from placement to removal. Results: Symptomatic CRT was present in 2.5% (7/276) of patients. Univariate analysis showed an increased risk of CRT in patients with a catheter-related infection (OR 2.4, 95% CI; 1.109–5.19, p = 0.026), previous thrombotic episode (OR 2.49, 95% CI; 1.15–5.39, p = 0.021), previous thrombotic episode on initial myeloma treatment (OR 2.75, 95% CI; 1.15–6.53, p = 0.022), and gastrointestinal complications of ASCT such as vomiting and diarrhea (OR 3.87, 95% CI; 1.57–9.53, p = 0.003). In multivariate analysis, noninfectious complications were associated with higher CRT incidence (OR 2.75, 95% CI; 1.10–6.19, p = 0.031). Conclusions: The incidence of symptomatic CRT in ASCT in MM was relatively low. Previous thrombotic events, especially during the induction of myeloma treatment, increased CRT risk during ASCT. Dehydration following gastrointestinal complications may predispose to higher CRT incidence.

Hemostatic parameters in patients with spinal cord injury in subacute and chronic phase of the rehabilitation

Objective: The goal of this study was to measure hemostatic markers after SCI.Design: Assesing changes in coagulation and fibrynilitic system in SCI patients in different time post injury to Cross-sectional study.Setting: Rehabilitation Department of the Bydgoszcz University Hospital, Poland from 2011 to 2017.Participants: SCI patient during acute and chronic rehabilitation (N = 88).Outcome Measures: Assesing following parameters: platelet counts and levels of D-dimer, antithrombin III (ATIII), tissue factor (TF), tissue factor pathway inhibitor (TFPI) and the inflammatory marker, C-reactive protein (CRP).Interventions: Eighty-eight SCI patients were divided into three groups based on the time elapsed from injury: group I (three weeks to three months), group II (three to twelve months) and group III (more than twelve months). All patients underwent ultrasonography (US) to detect acute or chronic recanalized deep vein thrombosis (DVT). Platelet counts and levels of D-dimer, ATIII, TF, TFPI and CRP were assessed. TF and TFPI levels were measured in the control group of forty healthy individuals without SCI, the rest of the parameters were compared to laboratory norms.Results: D-dimer levels were significantly higher in group I compared to group II (P = .0002) and group III (P < .001). Group II had higher D-dimer levels than group III (P = .032). TFPI levels were higher in group II compared with group III (P = .0041) and control group (P = .000033). TF was significantly higher in all the SCI groups compared with the control group (P < .001).Conclusions: D-dimer and TF levels were still elevated twelve months after SCI. TF levels were also elevated over 12 months after inury. The results may indicate that sub-acute and even chronic SCI patients have disturbed coagulation and fibrynolitic system.

Postoperative venous thromboembolism event increases risk of readmissions and reoperation following total joint arthroplasty: a propensity-matched cohort study

PURPOSE

The clinical impact of postoperative venous thromboembolism (VTE) following total joint arthroplasty (TJA) remains unclear. In this study, we evaluate the effect of VTE following TJA on postoperative outcomes including discharge disposition, readmission rates, and revision rates.

METHODS

We retrospectively reviewed all patients over the age of 18 who underwent primary, elective THA or TKA between 2013 and 2020. Patients were stratified into two cohorts based on whether or not they had a VTE following their procedure. Baseline patient demographics and clinical outcomes such as readmissions and revisions were collected. Propensity score matching was performed to limit significant demographic differences, while independent sample t-tests and Pearson's chi-squared test were used to compare outcomes of interest between the groups.

RESULTS

After propensity score matching, there were 109 patients in each cohort, representing a total of 218 patients for the matched comparison. Prior to matching, the VTE cohort was noted to have a significantly higher BMI than the non-VTE cohort (32.22 ± 6.27 vs 30.93 ± 32.04 kg/m², p = 0.032). All other patient demographics were similar. Compared to the non-VTE cohort, the VTE cohort was less likely to be discharged home (66.1% vs 80.7%; p = 0.021), had a higher rate of 90-day all-cause readmissions (27.5% vs 9.2%, p = 0.001), and a higher two-year revision rate (11.0% vs 0.9%, p = 0.003).

CONCLUSION

Patients with postoperative VTE were less likely to be discharged home and had higher 90-day readmission and two-year revision rates. Therefore, mitigating perioperative risk factors, initiating appropriate long-term anticoagulation, and maintaining close follow-up for patients with postoperative VTE may play significant roles in decreasing hospital costs and the economic burden to the healthcare system.

LEVEL OF EVIDENCE III

Retrospective Cohort Study.

Ischemic Stroke: An Underestimated Complication of COVID-19

The coronavirus disease 2019 (COVID-19) has spread rapidly as a pandemic around the world. In addition to severe acute respiratory syndrome, more and more studies have focused on the complication of COVID-19, especially ischemic stroke. Here, we propose several pathophysiological processes and possible mechanisms underlying ischemic stroke after COVID-19 for early prevention and better treatment of COVID-19-related stroke.

SARS-CoV-2 Infection: Modulator of Pulmonary Embolism Paradigm

Pulmonary embolism (PE) is a life-threatening complication arising from venous thromboembolism with a difficult diagnosis and treatment and is often associated with increased mortality and morbidity. PE had a significantly low incidence prior to the COVID-19 epidemic. This condition saw a sharp surge during the COVID-19 pandemic, indicating an evident viral influence on PE's pathophysiology in COVID-19 patients. The hypercoagulable state induced by the viral load seems to be the major contributor, and the classical causative factors seem to play a lesser role. PE in COVID-19 infection has become a mammoth challenge since the diagnosis is quite challenging due to overlapping symptoms, lack of prior-known predisposing risk factors, limited resources, and viral transmittance risk. Numerous factors arising out of the viral load or treatment lead to an increased risk for PE in COVID-19 patients, besides the fact that certain unknown risk factors may also contribute to the incidence of PE in COVID-19 patients. The management of PE in COVID-19 infection mainly comprises thromboprophylaxis and anticoagulant therapy with mechanical ventilation, depending on the risk stratification of the patient, with a post-COVID-19 management that prevents recurrent PE and complications. This review aims to discuss various aspects of COVID-19-infection-associated PE and major differential aspects from non-COVID-19 PE.

Infection, atherothrombosis and thromboembolism beyond the COVID-19 disease: what similar in physiopathology and researches

The recent Sars-Cov-2 pandemic (COVID-19) has led to growing research on the relationship between thromboembolism and Sars-Cov-2 infection. Nowadays, endothelial dysfunction, platelet activation, coagulation, and inflammatory host immune response are the subject of extensive researches in patients with COVID-19 disease. However, studies on the link between microorganisms or infections and thrombotic or thromboembolic events met fluctuating interest in the past. We, therefore, aimed to briefly summarize previous evidence on this topic, highlighting common points between previous data and what experienced today with SARS-COV2 infections.

Acute Pulmonary Embolism and COVID-19

Risk factors for pulmonary embolism in patients with coronavirus disease 2019 include obesity, an elevated d -dimer value, elevated C-reactive protein level, and a rising d -dimer value over time.

COVID-19 in critically ill patients in North Brabant, the Netherlands: Patient characteristics and outcomes

PURPOSE

Since the SARS-CoV-2 pandemic, countries are overwhelmed by critically ill Coronavirus disease 2019 (COVID-19) patients. As ICU capacity becomes limited we characterized critically ill COVID-19 patients in the Netherlands.

METHODS

In this case series, COVID-19 patients admitted to the ICU of the Jeroen Bosch Hospital were included from March 9 to April 7, 2020. COVID-19 was confirmed by a positive result by a RT-PCR of a specimen collected by nasopharyngeal swab. Clinical data were extracted from medical records.

RESULTS

The mean age of the 50 consecutively included critically ill COVID-19 patients was 65 ± 10 years, the mean BMI was 29 ± 4.7 and 66% were men. Seventy-eight percent of patients had ≥1 comorbidity, 34% had hypertension. Ninety-six percent of patients required mechanical ventilation and 80% were ventilated in prone position. Venous thromboembolism was recognized in 36% of patients. Seventy-four percent of patients survived and were successfully discharged from the ICU, the remaining 26% died (median follow up 86 days). The length of invasive ventilation in survivors was 15 days (IQR 12-31).

CONCLUSIONS

The survival rate of COVID-19 critically ill patients in our population is considerably better than previously reported. Thrombotic complications are commonly found and merit clinical attention.

TRIAL REGISTRATION NUMBER

NL2020.07.04.01.

Venous Thromboembolism in Hospitalized COVID-19 Patients

BACKGROUND

Venous thromboembolism (VTE) is increasingly reported in seriously ill patients with COVID-19 infection. Incidence of VTE has been reported before and results varied widely in study cohorts.

AREA OF UNCERTAINTY

Incidence of major VTE (segmental pulmonary embolism and above and proximal deep vein thrombosis) which is a contributor to mortality and morbidity is not known. Also, data is unclear on the optimal anticoagulation regimen to prevent VTE.

DATA SOURCES

Multiple databases including PubMed were searched until May 12, 2020, to include studies reporting VTE in hospitalized COVID-19 adult patients. MOOSE guidelines were followed in selection, and 11 studies were included. We conducted a systematic review and meta-analysis to quantitatively assess the VTE burden in hospitalized COVID-19 patients and potential benefits of therapeutic dosing of anticoagulation compared with prophylaxis dosing for VTE prevention.

THERAPEUTIC ADVANCES

Many societies and experts recommend routine prophylactic anticoagulation with heparin for VTE prevention in hospitalized COVID-19 patients. In this meta-analysis, the pooled rate of major VTE was 12.5% in hospitalized patients and 17.2% in intensive care unit patients. When therapeutic anticoagulation dosing was compared with prophylactic anticoagulation, the pooled odds ratio of VTE was 0.33 (95% confidence interval 0.14-0.75; P = 0.008, I = 0%) suggesting statistical significance with therapeutic dosing of anticoagulation for primary prevention of VTE in all hospitalized patients. However, this should be interpreted with caution as the bleeding events and safety profile could not be ascertained because of lack of adequate information. We recommend applying this finding to hospitalized COVID 19 patients only after carefully weighing individual bleeding risks and benefits.

CONCLUSION

Major VTE events, especially pulmonary embolism, seem to be high in COVID-19 patients admitted to the intensive care unit. Therapeutic anticoagulation dosing seems to significantly benefit the odds of preventing any VTE when compared with prophylactic dosing in all hospitalized patients.

Immunothrombosis and thromboinflammation in host defense and disease

Platelets are increasingly being recognized for playing roles beyond thrombosis and hemostasis. Today we know that they mediate inflammation by direct interactions with innate immune cells or secretion of cytokines/chemokines. Here we review their interactions with neutrophils and monocytes/macrophages in infection and sepsis, stroke, myocardial infarction and venous thromboembolism. We discuss new roles for platelet surface receptors like GPVI or GPIb and also look at platelet contributions to the formation of neutrophil extracellular traps (NETs) as well as to deep vein thrombosis during infection, e.g. in COVID-19 patients.

Thrombosis in Hospitalized Patients With COVID-19 in a New York City Health System

This study examines the incidence of and risk factors for venous and arterial thrombosis in patients hospitalized with COVID-19 in 4 New York City hospitals.

The novel coronavirus disease (COVID-19) complicated by pulmonary embolism and acute respiratory distress syndrome

Acute respiratory distress syndrome and coagulopathy played an important role in morbidity and mortality of severe COVID-19 patients. A higher frequency of pulmonary embolism (PE) than expected in COVID-19 patients was recently reported. The presenting symptoms for PE were untypical including dyspnea, which is one of the major symptoms in severe COVID-19, especially in those patients with acute respiratory distress syndrome (ARDS). We reported two COVID-19 cases with coexisting complications of PE and ARDS, aiming to consolidate the emerging knowledge of this global health emergency and raise the awareness that the hypoxemia or severe dyspnea in COVID-19 may be related to PE and not necessarily always due to the parenchymal disease.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Plasma levels of mannose-binding lectin and future risk of venous thromboembolism

BACKGROUND

Animal and observational studies have suggested a pathophysiological role for complement in venous thromboembolism (VTE), but the initiating mechanisms are unknown. Mannose-binding lectin (MBL) bound to altered host cells leads to activation of the lectin complement pathway, and both high and low MBL levels have been implicated in the pathophysiology of cardiovascular disease.

OBJECTIVES

To investigate the association between plasma MBL levels and future risk of incident VTE.

METHODS

We conducted a nested case-control study in 417 VTE patients and 849 age-matched and sex-matched controls derived from the general population (Tromsø Study). Plasma MBL levels were measured using enzyme-linked immunosorbent assay. Logistic regression models were used to estimate odds ratio (OR) for VTE across quartiles of plasma MBL levels.

RESULTS

Subjects with plasma MBL levels in the lowest quartile (<435 ng/mL) had a reduced OR for overall VTE (OR 0.79, 95% confidence interval [CI]: 0.56-1.10) and for DVT (OR 0.70, 95% CI: 0.47-1.04) compared to those with MBL in the highest quartile (≥2423 ng/mL) after multivariable adjustments. For VTE, DVT, and pulmonary embolism (PE) the ORs decreased substantially with decreasing time between blood sampling and VTE event.

CONCLUSIONS

Our findings suggest that low plasma MBL levels are associated with reduced risk of VTE, and DVT in particular.

The Role of Stroke as a Trigger for Incident Venous Thromboembolism: Results from a Population-based Case-Crossover Study

Stroke is associated with a short-term increased risk of subsequent venous thromboembolism (VTE). It is unclear to what extent this association is mediated by stroke-related complications that are potential triggers for VTE, such as immobilization and infection. We aimed to investigate the role of acute stroke as a trigger for incident VTE while taking other concomitant VTE triggers into account. We conducted a population-based case-crossover study with 707 VTE patients. Triggers were registered during the 90 days before a VTE event (hazard period) and in four preceding 90-day control periods. Conditional logistic regression was used to estimate odds ratios with 95% confidence intervals (CIs) for VTE according to triggers. Stroke was registered in 30 of the 707 (4.2%) hazard periods and in 6 of the 2,828 (0.2%) control periods, resulting in a high risk of VTE, with odds ratios of 20.0 (95% CI: 8.3–48.1). After adjustments for immobilization and infection, odds ratios for VTE conferred by stroke were attenuated to 6.0 (95% CI: 1.6–22.1), and further to 4.0 (95% CI: 1.1–14.2) when other triggers (major surgery, red blood cell transfusion, trauma, and central venous catheter) were added to the regression model. A mediation analysis revealed that 67.8% of the total effect of stroke on VTE risk could be mediated through immobilization and infection. Analyses restricted to ischemic stroke yielded similar results. In conclusion, acute stroke was a trigger for VTE, and the association between stroke and VTE risk appeared to be largely mediated by immobilization and infection.

Complement component 5 does not interfere with physiological hemostasis but is essential for Escherichia coli-induced coagulation accompanied by Toll-like receptor 4

There is a close cross-talk between complement, Toll-like receptors (TLRs) and coagulation. The role of the central complement component 5 (C5) in physiological and pathophysiological hemostasis has not, however, been fully elucidated. This study examined the effects of C5 in normal hemostasis and in Escherichia coli-induced coagulation and tissue factor (TF) up-regulation. Fresh whole blood obtained from six healthy donors and one C5-deficient individual (C5D) was anti-coagulated with the thrombin inhibitor lepirudin. Blood was incubated with or without E. coli in the presence of the C5 inhibitor eculizumab, a blocking anti-CD14 monoclonal antibody (anti-CD14) or the TLR-4 inhibitor eritoran. C5D blood was reconstituted with purified human C5. TF mRNA was measured by quantitative polymerase chain reaction (qPCR) and monocyte TF and CD11b surface expression by flow cytometry. Prothrombin fragment 1+2 (PTF1·2) in plasma and microparticles exposing TF (TF-MP) was measured by enzyme-linked immunosorbent assay (ELISA). Coagulation kinetics were analyzed by rotational thromboelastometry and platelet function by PFA-200. Normal blood with eculizumab as well as C5D blood with or without reconstitution with C5 displayed completely normal biochemical hemostatic patterns. In contrast, E. coli-induced TF mRNA and TF-MP were significantly reduced by C5 inhibition. C5 inhibition combined with anti-CD14 or eritoran completely inhibited the E. coli-induced monocyte TF, TF-MP and plasma PTF1·2. Addition of C5a alone did not induce TF expression on monocytes. In conclusion, C5 showed no impact on physiological hemostasis, but substantially contributed to E. coli-induced procoagulant events, which were abolished by the combined inhibition of C5 and CD14 or TLR-4.

C-reactive protein and risk of venous thromboembolism: results from a population-based case-crossover study

Long-term, low-grade inflammation does not seem to be a risk factor for venous thromboembolism. The impact of acute inflammation, regardless of cause, on risk of venous thromboembolism is scarcely studied. We aimed to investigate the impact of acute inflammation, assessed by C-reactive protein, on short-term risk of venous thromboembolism. We conducted a case-crossover study of patients with venous thromboembolism (n=707) recruited from a general population. Information on triggers and C-reactive protein levels were retrieved from hospital records during the 90 days before the event (hazard period) and in four preceding 90-day control periods. Conditional logistic regression was used to obtain β coefficients for change in natural log (ln) transformed C-reactive protein from control to hazard periods and to determine corresponding odds ratios for venous thromboembolism. Median C-reactive protein was 107 mg/L in the hazard period, and ranged from 7 mg/L to 16 mg/L in the control periods. The level of C-reactive protein was 58% (95% CI 39-77%) higher in the hazard period than in the control periods. A one-unit increase in ln-C-reactive protein was associated with increased risk of venous thromboembolism (OR 1.79, 95% CI 1.48-2.16). The risk estimates were only slightly attenuated after adjustment for immobilization and infection. In stratified analyses, ln-C-reactive protein was associated with increased risk of venous thromboembolism in cases with (OR 1.55, 95% CI 1.01-2.38) and without infection (OR 1.77, 95% CI 1.22-2.57). In conclusion, we found that acute inflammation, assessed by C-reactive protein, was a trigger for venous thromboembolism.