Previous studies have shown that COVID-19 diagnosis increases rates of perioperative infection, readmission, and other complications following surgery. However, the effect of the COVID vaccine in such patients is unknown. We hypothesized that of the patients with COVID diagnosis, vaccinated patients with COVID-19 diagnosis would have lower rates of adverse complications compared to unvaccinated patients undergoing total joint arthroplasty (TJA).

Using a national database registry, patients aged less than 85 years undergoing elective primary total knee or total hip arthroplasty with at least 90 days of follow-up were included during the first year of COVID-19 pandemic from April 2020-April 2021. Patients were included in the COVID-19 cohort if they had a diagnosis on the day of surgery or within 30 days prior to surgery. Patients with a history of malignancy, joint injection, femoral neck fractures, tibial fractures, and those undergoing revision arthroplasty were excluded from the study. All comparisons were performed using multivariate logistic regression with significance set at P < .05. Odds ratio and 95% confidence interval were reported for all comparisons.

There were a total of 1280 patients with COVID-19 diagnosis matched with 3831 patients without COVID-19 diagnosis. Patients with a COVID-19 diagnosis were at an increased risk of pneumonia, acute kidney injury, urinary tract infection, and readmission following TJA compared to patients without COVID-19 diagnosis. However, there were no differences in any complications assessed between vaccinated patients and unvaccinated patients with COVID-19 diagnosis following TJA.

This study confirms that patients with a COVID-19 diagnosis in the 30 days prior to TJA, whether vaccinated or not, have increased risks of medical complications and hospital utilization. However, this study demonstrates that vaccination status does not appear to be associated with the incidence of adverse postoperative events in patients with a COVID-19 diagnosis prior to TJA.

Background and Objectives: The study investigates the relationship between accessible biomarkers and the extent of lung damage, assessed with computed tomography (CT) imaging, in patients hospitalized for COVID-19. Materials and Methods: This retrospective analysis was conducted in a hospital in Cluj-Napoca, Romania, and it includes 111 patients diagnosed with moderate to severe forms of COVID-19 during the Delta and Omicron waves. We evaluated the association of affordable lab works, such as C-reactive protein (CRP), procalcitonin, ferritin, neutrophil and lymphocyte counts, D-dimers, and albumin levels, with the extents of lung injury, pleural effusion, pulmonary embolism, and thoracic adenopathy. Results: Our data show that high CRP, neutrophil counts, ferritin, and procalcitonin levels, combined with lower lymphocyte and albumin levels, were significantly associated with >25% lung damage (p < 0.05). Elevated ferritin (≥274 ng/mL) and neutrophil counts (≥5.2 × 109/L) were independently associated with this threshold. CRP (≥2.67 mg/dL), CRP/albumin ratio (≥0.736), and ferritin had the highest sensitivity (86.8%). D-dimer was the sole biochemical marker associated with pulmonary embolism (p = 0.036). Pleural effusion was independently associated with lymphocyte count (cut-off < 0.605 × 109/L, p = 0.013). Thoracic lymphadenopathy was also associated with increased neutrophil counts and a heightened inflammatory response. Conclusions: These findings suggest that ferritin and the CRP/albumin ratio can serve as indicators for patients with extensive parenchymal damage. D-dimer levels were the only ones significantly associated with thromboembolic events, while lymphopenia appears to be a useful indicator of pleural involvement. Thus, these readily available biomarkers can prove useful in anticipating radiological severity in patients hospitalized with COVID-19.

Background/Objectives: SARS-CoV-2 infection increases thrombotic events in hospitalized patients, especially those of greater severity. It has been associated with the cytokine storm and worsening renal and liver function, increased inflammatory markers, and altered coagulation markers. This study analyzes differences in inflammatory, hepatic, renal, and coagulation markers between hospitalized patients with and without COVID-19 who experienced thromboembolic events during the last three years of the pandemic. Methods: This single-center, retrospective observational study, with an inferential component and biomarker analysis, included 663 patients (600 without COVID-19, 63 with COVID-19) admitted between December 2022 and January 2023. Results: Patients with COVID-19 exhibited significantly higher mean glomerular filtration rate (GFR) (100.5 mL/min/1.73 m2; p < 0.01) and alanine aminotransferase (ALT) levels (33.0 IU/L; p < 0.01) compared to those without COVID-19. Ferritin levels were also significantly elevated in COVID-19 patients (441.1; p < 0.01), particularly those with severe disease. Conversely, troponin I was significantly higher in patients without COVID-19 (22.6 × 104 pg/mL; p < 0.001). Among COVID-19 patients, D-dimer levels were significantly higher in those not requiring intensive care unit (ICU) admission (9.0 × 103 ng/mL; p = 0.023). Multivariate analysis revealed a significant association between COVID-19 and sex. Conclusions: Overall, renal function did not differ significantly between COVID-19 and non-COVID-19 patients. However, renal function was better in patients admitted to the ICU, regardless of COVID-19 status. Troponin I levels were elevated in non-COVID-19 patients, while ferritin and ALT levels were higher in COVID-19 patients. D-dimer levels showed no significant difference between the two groups.

COVID-19 is associated with an increased risk of venous thromboembolism (VTE) in hospitalized patients. Although prior studies have attempted to identify predictors of VTE, restricted sample size and use of administrative claims data have limited such analyses. We utilized data from hospitalized patients in the CORONA-VTE Network, a United States multicenter registry of adult patients with PCR-confirmed COVID-19 (N = 3,844). The primary outcome was time-to-first event for a composite of adjudicated pulmonary embolism or deep vein thrombosis during 90-day follow-up. The candidate variables were selected by a priori clinical consensus. We conducted cause-specific Cox regression analysis adjusted for the selected variables for each imputed dataset and pooled the estimated HRs for reporting (p < 0.05 for significance). VTE occurred in 206 patients, with a cumulative incidence of 5.3% at 90 days. The covariates associated with increased risk of VTE were history of VTE (HR: 1.71; 95% CI: 1.11-2.63), corticosteroid therapy (HR: 1.76; 95% CI: 1.32-2.33) and known thrombophilia (HR: 3.56; 95% CI: 1.54-8.21) while therapeutic anticoagulation at baseline (HR: 0.42; 95% CI: 0.26-0.69), antecedent use of statins (HR: 0.67; 95% CI: 0.50-0.90), and prophylactic anticoagulation during hospitalization (HR: 0.52; 95% CI: 0.38-0.71) were associated with reduced risk of VTE. While prior VTE, corticosteroid therapy, and known thrombophilia were associated with an increased risk of VTE, prescriptions of prophylactic and therapeutic anticoagulation, and statins were associated with a decreased risk. Once externally validated, these findings may inform risk assessment in hospitalized patients with COVID-19.

Previous studies have reported a greater risk of venous thromboembolism among patients infected with SARS-CoV-2 and those who received COVID-19 vaccination. Nevertheless, there is a lack of understanding regarding the interaction effect on the risk of venous thromboembolism occurrence between SARS-CoV-2 infection and COVID-19 vaccination.

This was a retrospective cohort study including adult patients with confirmed SARS-CoV-2 infection between October 2020 and September 2021. Patients with confirmed SARS-CoV-2 infection were selected and matched 1:1 by age and sex with individuals who were not infected during the same period. A Cox proportional hazards model was used to analyze the venous thromboembolism risk.

The study included 422546 individuals who were divided into 4 groups; the interaction group defined by having SARS-CoV-2 infection within 90 days following COVID-19 vaccination, the infection group defined by no vaccination before 90 days of SARS-CoV-2 infection, the vaccination group defined by COVID-19 vaccination without SARS-CoV-2 infection, and the reference group defined by neither COVID-19 vaccination nor SARS-CoV-2 infection. The results showed that the adjusted hazard ratio (aHR) of the interaction group was 29.71 (95% confidence interval [CI], 22.95-38.47), while the aHRs of the infection group and the vaccination group were 6.66 (95% CI, 5.18-8.58) and 2.31 (95% CI, 1.78-3.00), respectively.

A synergistic effect on the risk of venous thromboembolism was suggested when individuals were infected with SARS-CoV-2 within 90 days following COVID-19 vaccination.

This study compared the efficacy of therapeutic anticoagulation guided by anti-Xa levels vs. a D-dimer-based protocol in ICU patients with COVID-19. Given the heightened risk of thrombosis despite anticoagulation therapy in some cases, we hypothesised that anti-Xa measurement improves anticoagulation effectiveness and clinical outcomes in this population. We retrospectively analysed data from ICU patients at COVID Hospital Karaburma between April 2020 and December 2021. The primary outcome was the incidence of failed noninvasive ventilation necessitating intubation. Secondary endpoints included mortality rates, thromboembolic and bleeding complications, and anticoagulation effectiveness assessed by antifactor Xa activity. The analysis included 395 patients - 137 in the anti-Xa group and 258 in the D-dimer group. The D-dimer group showed a higher rate of failed noninvasive ventilation requiring intubation (65.7% vs. 50%, P  = 0.009). The overall mortality was 48.3%, significantly higher in the D-dimer group (52.7%) compared to the anti-Xa group (40.1%, P  = 0.02). Thromboembolic complications were lower in the anti-Xa group (2.9%) than in the D-dimer group (9.7%, P  = 0.014), with no significant difference in bleeding. Following the first LMWH administration, 70.8% of patients had anti-Xa levels below the therapeutic and 11.7% below the prophylactic range. Anti-Xa-guided anticoagulation improves survival and reduces thromboembolic complications compared to D-dimer-based treatment without increasing bleeding risk. This study highlights the potential of the anti-Xa assay in managing anticoagulation in critically ill COVID-19 patients. Our findings provide a foundation for future research on using anti-Xa measurements as a guiding tool to optimise anticoagulation therapy in other critically ill populations.

COVID-19-related critical and acute illness is associated with an increased risk of venous thromboembolism (VTE). These evidence-based recommendations of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about using anticoagulation for thromboprophylaxis for patients with COVID-19-related critical illness; patients with COVID-19-related acute illness; and those being discharged from the hospital, who do not have suspected or confirmed VTE.

ASH formed a multidisciplinary panel, including patient representatives. The Michael G. DeGroote Cochrane Canada and MacGRADE Centres at McMaster University supported guideline development, including performing systematic reviews (up to June 2023). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess certainty in the evidence and make recommendations.

This is an executive summary of 3 updated recommendations that have been published, which concludes the living phase of the guidelines. For patients with COVID-19-related critical illness, the panel issued conditional recommendations suggesting (a) prophylactic-intensity over therapeutic-intensity anticoagulation and (b) prophylactic-intensity over intermediate-intensity anticoagulation. For patients with COVID-19-related acute illness, conditional recommendations were suggested (a) prophylactic-intensity over intermediate-intensity anticoagulation, and (b) therapeutic-intensity over prophylactic-intensity anticoagulation. The panel issued a conditional recommendation suggesting against the use of postdischarge anticoagulant thromboprophylaxis.

These conditional recommendations were made based on low or very low certainty in the evidence, underscoring the need for additional, high-quality, randomized controlled trials for patients with COVID-19.

Background: Pulmonary embolism (PE) remains a major concern in emergency patients presenting with respiratory symptoms, with an increase in the demand for CT pulmonary angiography (CTPA) and low yields of this ever more sensitive test. We wanted to investigate factors associated with pulmonary embolism on CTPA, aiming to reduce unnecessary requests. Methods: In a single-center, retrospective study, we analyzed all CTPA reports for emergency patients during the year 2023. Various patients' variables were evaluated for associations with the presence/absence of PE, including the presence or absence of pulmonary pathology identified prior to the CTPA order. Results: A total of 1555 CTPA reports were analyzed, of which 278 (17.9%) were positive for PE. The highest ORs (40.9) for PE were found for patients diagnosed with DVT prior to CTPA. The lowest odds ratios of having PE were found for patients with acute congestive heart failure (OR = 0.141), especially in the absence of cancer (OR = 0.089) and for patients with hypercapnia in COPD exacerbation (OR = 0.062). Tachycardia and hypoxemia were the physiological variables positively associated with PE, while hypercapnia was negatively associated with PE. For patients with heart failure, COPD exacerbation, and pneumonia, higher D-dimer cut-off values (3.87 mg/L, 1.25 mg/L, and 1.34 mg/L, respectively) were found to retain 100% sensitivity for PE. Conclusions: Stricter criteria for CTPA orders in the presence of other pulmonary pathologies may reduce unnecessary scanning. Higher D-dimer cut-off values in such cases may lead to higher specificity without sacrificing sensitivity.

The aim of this study was to evaluate the association between SARS-CoV-2 vaccination and the occurrence of thrombotic complications in patients admitted to intensive care for severe COVID-19 pneumonia.

Observational, descriptive, prospective, multicentre study.

Intensive care units of five university hospitals.

A total of 255 patients admitted to the intensive care unit (ICU) with SARS-CoV-2 pneumonia, confirmed by RT-PCR in throat swab or tracheal aspirate, starting the date the first vaccinated patient against SARS-CoV-2 was admitted in one of the participating ICUs, were included in the analysis.

Vaccination status against SARS-CoV-2 and thrombotic events.

18.8% of patients had received some form of vaccination. Thrombotic events occurred in 21.2% of patients. Lack of vaccination was associated with thrombotic events (OR 5.024; 95% CI: 1.104-23.123; p = 0.0037) and death (OR 5.161; 95% CI: 1.075-24.787; p = 0.04). ICU mortality was not associated with the occurrence of thrombotic complications.

In this series of patients, vaccination against SARS-CoV-2 reduced the risk of thrombotic events and mortality in patients with severe COVID-19 admitted to the ICU. Thrombotic complications did not alter ICU mortality.

We aimed to determine the predictive accuracy of elevated soluble thrombomodulin (sTM) and angiopoietin-2 (Ang2) for thrombotic events (TE) in hospitalized COVID-19 patients. We conducted a nested case-control study within a cohort of people admitted to hospital with COVID-19 from March 2020 to August 2022. The cases (people with TE within 28 days after hospital admission) were matched by propensity score to comparable patients without TE. We determined plasma levels of sTM and Ang2 in all available frozen samples, prioritizing the earliest post-admission samples, using an automated immunoassay technique. Among 2,524 hospitalized COVID-19 patients (43% females; median age 67 years), 73 had TE (incidence 1.15 events per 1000 patient-days of follow-up). Frozen plasma samples were available for 43 cases and 176 controls. Elevated plasma concentration of sTM was significantly associated with TE (2.8 [1.8, 4] vs. 1.52 [1.1, 2.65] ng/mL; p =  0.001) and mortality (median [Q1, Q3], 3.32 [2.16, 4.65] vs. 1.58 [1.11, 2.73] ng/mL; p =  0.001), while D-dimer showed a specific association with TE (2.3 [0.8, 7.4] vs. 0.75 [0.4, 1.6] mcg/mL; p =  0.001). In contrast, Ang2 was not associated with any of these events. The association with thrombotic events remained in adjusted models (HR [95%CI] per unit increase, 1.24 [1.04-1.47] for sTM; 1.07 [1.03-1.10] for D-dimer). The adjusted regression model that included both biomarkers, sTM and D-dimer, improved (AUC 73%, sensitivity 77% and specificity 65% for TE diagnosis; p =  0.007) the predictive capacity of the same model without sTM. In conclusion, determination of soluble thrombomodulin along with D-dimer enhances thrombotic risk assessment in hospitalized COVID-19 patients.

The association between COVID-19 and coagulation disorders has been discussed since the onset of the pandemic. Four years into the pandemic, it is crucial to organize the findings and evidence accumulated thus far. The objective of this study was to review and synthesize the available scientific evidence regarding the relationship between COVID-19 and development of venous thromboembolism (VTE). A rapid systematic review was conducted by searching two electronic databases, selecting systematic review articles that assessed the association between COVID-19 and development of VTE, such as deep vein thrombosis (DVT) or pulmonary embolism (PE). The studies indicated that hospitalized COVID-19 patients are at greater risk of developing VTE, especially those admitted to intensive care units (ICUs). Elevated D-dimer levels and male gender were also associated with increased risks.

Throughout the pandemic, it has become evident that COVID-19 should be recognized as a systemic disease that can affect the coagulation system, potentially resulting in arterial thrombotic events (ATE) with partially bulky free-floating clots. This study aimed to investigate the incidence and imaging characteristics of ATE in hospitalized patients with COVID-19 using clinical and imaging data.

From January 2020 to May 2021, databases of five German tertiary care centers were retrospectively screened for COVID-19 patients with coincidental ATE. ATE were analyzed for localization, time of occurrence, imaging characteristics, and associations with clinical data and laboratory parameters.

Out of 3267 patients, 110 ATE (102 patients, mean age, 72.01 ± 15.64 years; 63 men) were observed in the presence of COVID-19 (3.1%). ATE included ischemic stroke (40%), myocardial infarction (46.4%, %), peripheral infarction (3.6%), thrombi in precerebral arteries (3.6%), mesenteric ischemia (2.7%), thrombi in the aorta (1.8%), splenic infarction (0.9%), and kidney infarction (0.9%). The median time interval between the onset of typical respiratory COVID-19 symptoms and ATE was four days (range, -5-58, negative values indicate ATE prior to symptom onset). A significant percentage of patients exhibited ATEs with an atypical free-floating appearance (10.0%) and multiple occlusions (21.2%).

COVID-19 is a systemic disease associated with ATE in all vascular regions, with a predilection for the heart and brain. The incidence of ATE might be higher than in comparable viral infections and ATE possibly exhibit distinct imaging features rarely seen, such as bulky free-floating clot masses and multiple occlusions. ATE occur most frequently during the first week around the COVID-19 diagnosis.

The COVID-19 pandemic has been associated with a broad spectrum of clinical manifestations, including multisystem inflammatory syndrome in children (MIS-C), a rare but serious condition characterized by a proinflammatory and hypercoagulable state. MIS-C has been linked to an elevated risk of venous thromboembolism (VTE), necessitating a focus on thromboprophylaxis to prevent potentially fatal complications in pediatric patients. This systematic review aims to evaluate the association between COVID-19/MIS-C and thromboembolism and to assess the efficacy of thromboprophylaxis protocols in reducing thrombotic events and mortality in children. A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Literature searches were performed in PubMed, Cochrane, and Science Direct databases. Randomized controlled trials, cohort studies, and case-control studies reporting on thromboprophylaxis, thrombotic events, and associated outcomes in pediatric patients (<21 years) with COVID-19 and/or MIS-C were included. The Newcastle-Ottawa Scale was used to assess the quality of included studies. Primary outcomes were the incidence of thrombotic events and mortality, while secondary outcomes included bleeding events, clinical recovery, and changes in coagulation markers. Of the 375 articles identified, three studies (n=771 patients) met the inclusion criteria. Thromboprophylaxis protocols primarily included low molecular weight heparin (LMWH) such as enoxaparin and antiplatelet agents such as aspirin, with varied doses and treatment durations. Thrombotic events were reported in 3.3% of patients, with a higher incidence in MIS-C cases compared to COVID-19 alone. Prophylactic anticoagulation was effective in preventing thrombotic events in high-risk patients without increasing the risk of major bleeding. The studies emphasized individualized treatment approaches based on risk factors such as elevated D-dimer levels, obesity, prolonged immobilization, and central venous catheter presence. All studies reported a low mortality rate, ranging from 0% to 2.2%, highlighting the potential benefit of thromboprophylaxis in this population. Pediatric patients with MIS-C or severe COVID-19 are at an increased risk of thrombotic complications due to their heightened proinflammatory and hypercoagulable states. Thromboprophylaxis using enoxaparin and aspirin appears effective in reducing thrombotic events and mortality in these patients. Individualized protocols based on clinical risk factors and D-dimer levels are critical to optimizing outcomes while minimizing bleeding risks. Standardized, evidence-based guidelines are needed to refine thromboprophylaxis strategies and determine the optimal duration of therapy in this vulnerable population. Further research is essential to better understand the role of coagulation markers in guiding treatment cessation and improving outcomes.

Deep vein thrombosis (DVT) of the legs is a rare but clinically important complication of Chlamydia psittaci pneumonia. We report a case of a 51-year-old man who was admitted to the hospital with fever, cough, and dyspnea. Next-generation sequencing confirmed the diagnosis of Chlamydia psittaci pneumonia. His D-dimer level was elevated on admission, and ultrasound confirmed DVT in the legs. The patient was treated with intravenous doxycycline for the infection and rivaroxaban as an anticoagulant. His condition gradually improved and he was discharged after making a full recovery. In this paper, we explore the potential association between Chlamydia psittaci infection and venous thrombosis, as well as clinical management strategies.

This review article discusses the role of vascular endothelial growth factor A (VEGF-A) in the pathogenesis of SARS-CoV-2 and HIV infection, both conditions being renowned for their impact on the vascular endothelium. The processes involved in vascular homeostasis and angiogenesis are reviewed briefly before exploring the interplay between hypoxia, VEGF-A, neuropilin-1 (NRP-1), and inflammatory pathways. We then focus on SARS-CoV-2 infection and show how the binding of the viral pathogen to the angiotensin-converting enzyme 2 receptor, as well as to NRP-1, leads to elevated levels of VEGF-A and consequences such as coagulation, vascular dysfunction, and inflammation. HIV infection augments angiogenesis via several mechanisms, most prominently, by the trans-activator of transcription (tat) protein mimicking VEGF-A by binding to its receptor, VEGFR-2, as well as upregulation of NRP-1, which enhances the interaction between VEGF-A and VEGFR-2. We propose that the elevated levels of VEGF-A observed during HIV/SARS-CoV-2 co-infection originate predominantly from activated immune cells due to the upregulation of HIF-1α by damaged endothelial cells. In this context, a few clinical trials have described a diminished requirement for oxygen therapy during anti-VEGF treatment of SARS-CoV-2 infection. The currently available anti-VEGF therapy strategies target the binding of VEGF-A to both VEGFR-1 and VEGFR-2. The blocking of both receptors could, however, lead to a negative outcome, inhibiting not only pathological, but also physiological angiogenesis. Based on the examination of published studies, this review suggests that treatment targeting selective inhibition of VEGFR-1 may be beneficial in the context of SARS-CoV-2 infection.

There are no clear data on the incidence and predictors of arterial and venous thromboembolic (TE) events in COVID-19 ambulatory patients.

We conducted this study to analyze thromboembolic complications in this setting and to compare the efficacy and safety of Rivaroxaban to LMWHs as a thromboprophylaxis treatment.

This is an observational study including COVID-19 patients treated on an outpatient basis. We analysed the predictors of thromboembolic events.

We included 2089 patients with COVID19 managed on an outpatient basis during the period from October 01, 2020 to December 31, 2021. The mean age of our patients was 43±16 years. The incidence of venous and arterial TE complications was 0.9%. Predictive factors for arteriovenous thromboembolic complications were hormonal contraception (OR=23), moderate clinical form (OR=3.5), recent surgery or miscarriage in the month preceding COVID-19 (OR=9.2) and CT signs of COVID-19 (OR=4.9). In contrast, physical activity proved to be a protective factor. Thromboprophylaxis was prescribed in 22.5% of cases: LMWH in 18.1%, Rivaroxaban in 3.7% and a combination of the two molecules successively in 0.6% of patients. There was no statistical difference in thromboembolic or major bleeding complications between the Rivaroxaban and LMWH groups.

Our study showed that the incidence of thromboembolic complications is very low in Covid-19 ambulatory patients.

Despite the morbidity and mortality of venous thromboembolism, there is little evidence to guide postpartum thromboprophylaxis in patients at moderate risk. We aimed to assess the feasibility of conducting a double-blind, randomised trial of aspirin versus placebo in postpartum individuals with two or more venous thromboembolism risk factors, mild-to-moderate thrombophilia, or both.

The pilot PARTUM trial, a multi-national, randomised, double-blind, placebo-controlled trial, was conducted in seven centres across Canada, France, Ireland, and the Netherlands. Postpartum individuals aged 18 years or older with venous thromboembolism risk factors, including mild-moderate inherited thrombophilia, antepartum immobilisation, pre-pregnancy BMI of 30 kg/m2 or higher, pre-pregnancy smoking, previous superficial vein thrombosis, and other pregnancy-related conditions, were eligible. Participants were randomly assigned (1:1) within 48 h of delivery to aspirin 81 mg (80 mg in Europe) orally daily (low-dose aspirin group) or placebo orally once daily (placebo group) for 42 days. Follow-up visits occurred at 6 weeks and 90 days postpartum. The primary outcome was the mean recruitment rate (participants per site per month). Additional feasibility metrics were reported, and clinical outcomes were analysed by intention to treat. This study is registered with ClinicalTrials.gov, NCT04153760, and EudraCT, 2020-000619-58, and is completed.

Between Nov 2, 2020, and June 19, 2023, 10 040 patients were assessed for eligibility and 808 met all eligibility criteria, of whom 257 (32%) provided consent and were enrolled. 127 were randomly assigned to the low-dose aspirin group and 130 to the placebo group. The median follow-up was 91 days (IQR 89-96). The median age was 34·0 years (IQR 30·0-37·0), and 161 (63%) of participants were White. The mean recruitment rate was 6·3 (95% CI 5·5 to 7·2) patients per site per month. No venous thromboembolism events occurred in the low-dose aspirin group, and one participant had distal deep vein thrombosis in the placebo group (-0·82 [95% CI -2·42 to 0·78]). No major bleeds occurred. Three (2%) participants in the low-dose aspirin group versus one (1%) in the placebo group had clinically relevant non-major bleeds (absolute risk difference 1·66 [95% CI -1·54 to 4·86]). Ten serious adverse events occurred in nine (4%) of 257 participants, and 11 serious adverse events occurred in ten (4%) of 271 infants of participants. No treatment-related death occurred.

A global postpartum thromboprophylaxis trial evaluating low-dose aspirin is possible and needed to provide high-quality data.

Canadian Institutes of Health Research and the INVENT-VTE Network.

To determine the incidence of VTE and clinical outcomes in a cohort of cancer patients and COVID-19 infection, and to establish possible predictive factors of VTE.

A single-center retrospective cohort study was performed to determine the incidence of VTE and mortality in 118 cancer patients with SARS-CoV-2 infection from March to August 2020. We calculated individual Khorana Risk and CATS-MICA scores in order to evaluate their utility to identify risk of VTE or death. Continuous variables were compared using Wilcoxon or Student's T test, and categorical variables were compared using the Chi-Square or Fisher's exact text among patients with and without VTE. A Log-Rank test was performed to detect mortality differences between the groups.

A total of 118 patients were included. VTE global incidence was 4.2% (n = 5), and mortality 25.4% (n = 30). Obesity (p = 0.05), recent chemotherapy (p = 0.049) and use of steroids (p = 0.006) were related to higher risk of VTE in the univariate analysis, although they were not confirmed in the multivariate analysis as independent risk factors. Statistically significant differences in all-cause, COVID-19-related and cancer-related mortality according to the Khorana risk score (KRS) were observed. CATS-MICA score (CMS) also showed statistically significant differences in mortality between low- and high-risk patients. Prediction of risk of VTE development with these scores showed a tendency towards significance.

In this cohort, VTE incidence was similar to previously reported in the general population with SARS-CoV-2 infection. KRS was associated with overall and specific-cause mortality, and might be a useful prognostic tool in this setting.

Aim We aimed to determine the incidence of thrombotic complications and outcomes of critically ill COVID-19 patients admitted to the intensive care unit (ICU) and evaluate the association between combined antithrombotic therapy and mortality in ICU patients admitted for COVID-19 pneumonia. Methods We retrospectively collected data of adult critically ill patients with COVID-19 admitted to the ICU in a major hospital in Dubai during the COVID-19 pandemic. The primary outcome was in-hospital mortality. Secondary outcomes included the incidence of major complications, such as thrombotic complications during the ICU stay. The study population was classified into two groups based on the type of prophylactic anticoagulant and antiplatelet therapy received. Results The study included 257 ICU patients admitted with COVID-19 pneumonia. The mean duration of their ICU stay was 24.95 days, ranging from one day to 327 days. The primary outcome was in-hospital mortality. In our study, 151 patients (58.7%) suffered in-hospital mortality. Secondary outcomes included the incidence of major complications during the ICU stay. A total of 202 patients (78.6%) presented with acute respiratory distress syndrome. Ninety-nine (38.5%) of the patients had progressed to acute kidney injury. Thirty-three patients (12.8%) had various thrombotic complications. Three of these (9%) had venous thrombosis, and 30 patients (91%) had arterial thrombosis. Ischemic stroke was the major thrombotic complication of COVID-19 (36.3% of overall thrombotic events, n = 12), followed by myocardial infarction (27.2%; n = 9) and pulmonary embolism (21.2%; n = 7). Out of 257 COVID-19 ICU patients, 73 patients (28.4%) received both anticoagulants and antiplatelet therapy, and 183 patients (70.8%) received only anticoagulant therapy. We compared the mortality of COVID-19 ICU patients who received anticoagulants alone to those with added antiplatelets. The application of combined antiplatelet and anticoagulants as thromboprophylaxis for COVID-19 ICU patients was not associated with a significant reduction in mortality (P = 0.868). Peak serum levels of D-dimer significantly correlate with the length of ICU stay (rho = 0.137, P = 0.031). Peak D-dimer level during the ICU stay was statistically significantly higher in non-survivors (mean = 11.87) compared to survivors (mean = 8.59) (P < 0.001). D-dimer on ICU admission had a good prognostic value for ICU patients with COVID-19 infection (P = 0.018). Conclusion The incidence of thrombotic complications among COVID-19 pneumonia patients admitted to ICU is remarkably high, which reinforces the recommendation to apply thrombosis prophylaxis strictly to all ICU patients admitted with COVID-19. The application of combined antiplatelets with anticoagulants as thromboprophylaxis for COVID-19 ICU patients was not associated with a significant reduction in ICU mortality. D-dimer has a significant correlation with prognosis and length of ICU stay of COVID-19 patients.

CD209L and its homologous protein CD209 act as alternative entry receptors for the SARS-CoV-2 virus and are highly expressed in the virally targeted tissues. We tested for the presence and clinical features of autoantibodies targeting these receptors and compared these with autoantibodies known to be associated with COVID-19.

Using banked samples (n = 118) from Johns Hopkins patients hospitalised with COVID-19, we defined autoantibodies against CD209 and CD209L by enzyme-linked immunosorbent assay (ELISA). Clinical associations of these antibodies were compared with those of patients with anti-interferon (IFN) and anti-angiotensin-converting enzyme-2 (ACE2) autoantibodies.

Amongst patients hospitalised with COVID-19, 19.5% (23/118) had IgM autoantibodies against CD209L and were more likely to have coronary artery disease (44% vs 19%, P = 0.03). Antibodies against CD209 were present in 5.9% (7/118); interestingly, all 7 were male (P = 0.02). In our study, the presence of either antibody was positively associated with disease severity [OR 95% confidence interval (95% CI): 1.80 (0.69-5.03)], but the association did not reach statistical significance. In contrast, 10/118 (8.5%) had IgG autoantibodies against IFNα, and 21 (17.8%) had IgM antibodies against ACE2. These patients had significantly worse prognosis (intubation or death) and prolonged hospital stays. However, when adjusting for patient characteristics on admission, only the presence of anti-ACE2 IgM remained significant [pooled common OR (95% CI), 4.14 (1.37, 12.54)].

We describe IgM autoantibodies against CD209 and CD209L amongst patients hospitalised with COVID-19. These were not associated with disease severity. Conversely, patients with either anti-ACE2 IgM or anti-IFNα IgG antibodies had worse outcomes. Due to the small size of the study cohort, conclusions drawn should be considered cautiously.

Few epidemiological data are available for venous thromboembolism (VTE) at French national and subnational levels.

To quantify VTE events in France in 2022 and describe the features of hospital management and outcomes.

Adults hospitalized for a VTE as the primary reason for hospitalization or treatment in a medical unit in 2022 were identified from medical administrative data. Data were stratified as pulmonary embolism (PE) and deep vein thrombosis (DVT), and by French department and various sociodemographic indicators. VTE prevalence at 1 January 2023 was defined as the number of people alive at that date with a history of hospitalization for VTE or a chronic long-term disease status due to VTE (2012-2022).

VTE cases reached 896,846 adults on 1 January 2023. VTE was the primary diagnosis for a hospital stay or medical unit in 62,055 patients hospitalized in 2022. The age-standardized rate of hospitalized patients was 23.0% higher for men versus women. There were considerable variations between departments of residence, while Martinique had the highest age-standardized rate. The prevalence of triggering factors was high, with almost 30% having cancer and 20% a recent long hospitalization. One-year mortality was approximately 20% for both PE and DVT, despite rehospitalization rates <5%.

The high prevalence of cancer among patients hospitalized due to VTE partly explains the high 1-year mortality. As VTE is partially avoidable, the prevention of VTE needs to be improved in France and whether thromboprophylaxis guidance is being followed should regularly be assessed.

Currently, CT pulmonary angiogram (CTPA) for evaluating acute pulmonary embolism (PE) in emergency departments (EDs) is overused and with low yields. The goal of this study is to assess the impact of an evidence-based clinical decision support (CDS) tool, aimed at optimizing appropriate use of CTPA for evaluating PE.

The study was performed at EDs in a large health care system and included nine academic and community hospitals. The primary outcome was the percent difference in utilization (number of CTPAs performed per number of ED visits) and secondary outcome was yield (percentage of CTPAs positive for acute PE), comparing 12 months before (June 1, 2021, to May 31, 2022) versus 12 months after (June 1, 2022, to May 31, 2023) a systemwide implementation of the CDS. Univariate and multivariable analyses using logistic regression were performed to assess factors associated with diagnosis of acute PE. Statistical process control charts were used to assess monthly trends in utilization and yield.

Among 931,677 visits to EDs, 28,101 CTPAs were performed on 24,675 patients. In all, 14,825 CTPAs were performed among 455,038 visits (3.26%) pre-intervention and 13,276 among 476,639 visits (2.79%) postintervention, a 14.51% relative decrease in CTPA utilization (χ2, P < .001). CTPA yield remained unchanged (1,371 of 14,825 = 9.25% pre- versus 1,184 of 13,276 = 8.92% postintervention; χ2, P = .34). Patients with coronavirus disease of 2019 diagnosis before CTPA had higher probability of acute PE. Statistical process control charts demonstrated seasonal variation in utilization (Friedman test, P = .047).

Implementing a CDS based on validated decision rules was associated with a significant reduction in CTPA utilization. The change was immediate and sustained for 12 months postintervention.

Coronavirus disease 2019 (COVID-19) is known to increase the risk of venous thromboembolism (VTE) and arterial thromboembolism (ATE). However, the incidence, predictors, and outcomes of clinical thrombosis for inpatients with COVID-19 are not well known. This study aimed to enhance our understanding of clinical thrombosis in COVID-19, its associated factors, and mortality outcomes.

Hospitalised adult (≥18 years of age) patients with COVID-19 in 2020 were retrospectively identified from the US National Inpatient Sample database. Clinical characteristics, incident VTE, ATE, and in-hospital mortality outcomes were recorded. Multivariable logistic regression was performed to identify clinical factors associated with thrombosis and in-hospital mortality in COVID-19 inpatients.

A total of 1,583,135 adult patients with COVID-19 in the year 2020 were identified from the National Inpatient Sample database; patients with thrombosis were 41% females with a mean age of 65.4 (65.1-65.6) years. The incidence of thrombosis was 6.1% (97,185), including VTE at 4.8% (76,125), ATE at 3.0% (47,790), and the in-hospital mortality rate was 13.4% (212,785). Patients with thrombosis were more likely to have respiratory symptoms of COVID-19 (76.7% vs 75%, p<0.001) compared with patients without thrombosis. The main factors associated with overall thrombosis, VTE, and ATE were paralysis, ventilation, solid tumours without metastasis, metastatic cancer, and acute liver failure. Although all thrombosis categories were associated with higher in-hospital mortality for COVID-19 inpatients in univariable analyses (p<0.001), they were not in multivariable analyses-thrombosis (odds ratio [OR] 1.24; 95% confidence interval [CI] 0.90-1.70; p=0.19), VTE (OR 0.70; 95% CI 0.52-1.00; p=0.05), and ATE (OR 1.07; 95% CI 0.92-1.25; p=0.36).

The association of COVID-19 with thrombosis and VTE increases with increasing severity of the COVID-19 disease. Risk stratification of thrombosis is crucial in COVID-19 patients to determine the necessity of thromboprophylaxis.

Inpatient and extended postdischarge thromboprophylaxis of COVID-19 patients remains suboptimal despite antithrombotic guidelines.

To determine whether a novel electronic health record-agnostic clinical decision support (CDS) tool incorporating the International Medical Prevention Registry on Venous Thromboembolism plus D-dimer (IMPROVE-DD) venous thromboembolism (VTE) scores increases appropriate inpatient and extended postdischarge thromboprophylaxis and improves outcomes in COVID-19 inpatients.

This post hoc analysis of the IMPROVE-DD cluster randomized trial evaluated thromboprophylaxis CDS among COVID-19 inpatients at 4 New York hospitals between December 21, 2020, and January 21, 2022. Hospitals were randomized 1:1 to CDS (intervention, n = 2) vs no CDS (usual care, n = 2). The primary outcome was rate of appropriate thromboprophylaxis. Secondary outcomes included rates of major thromboembolism, all-cause and VTE-related readmissions and death, major bleeding (MB), and all-cause mortality 30 days after discharge.

Two thousand four hundred fifty-two COVID-19 inpatients were analyzed (CDS, 1355; no CDS, 1097). Mean age was 73.7 ± 9.37 years; 50.1% of participants were male. CDS adoption was 96.8% (intervention group). CDS was associated with increased appropriate at-discharge extended thromboprophylaxis (42.6% vs 28.8%; odds ratio [OR], 1.83; 95% CI, 1.39-2.41; P < .001). CDS was associated with reduced VTE (OR, 0.54; 95% CI, 0.39-0.75; P < .001), arterial thromboembolism (OR, 0.10; 95% CI, 0.01-0.81; P = .01), total thromboembolism (OR, 0.50; 95% CI, 0.36-0.69; P < .001), and 30-day all-cause readmission/death (OR, 0.78; 95% CI, 0.62-0.99; P = .04). There were no differences in MB, VTE-related readmissions/death, or all-cause mortality.

Electronic health record-agnostic CDS incorporating IMPROVE-DD VTE scores had high adoption, was associated with increased appropriate at-discharge extended thromboprophylaxis, and reduced thromboembolism and all-cause readmission/death without increasing MB in COVID-19 inpatients.

The prevalence of concomitant deep vein thrombosis (DVT) and its impact on 30-day outcomes in Hispanic patients with acute pulmonary embolism (PE) is unknown. We retrospectively studied a cohort of Hispanic patients admitted for acute PE to determine the relationship of concomitant DVT to clot burden on chest computer tomography (CT), right heart strain, and 30-day mortality. We identified 391 patients admitted with acute PE; 168 (42.9%) had concomitant DVTs on admission; 39 patients (9.9%) died during the 30-day follow-up: 12 patients without concomitant DVT and 27 with concomitant DVT, respectively (p < .001). The presence of a proximal DVT independently predicted 30-day mortality even after adjusting for age, gender and admission PE severity index scores (PESI) (hazard ratio [HR] 2.0; 95% confidence interval [CI]: 1.4-3.0, p = .001). Proximal DVTs remained a significant predictor of 30-day mortality in patients with low and intermediate PESI scores (HR 2.5; 95% CI: 1.1-6.0, p = .035). The prevalence of concomitant DVT in Hispanic patients presenting with acute DVT is relatively lower than other ethnic groups. However, a proximal location of a DVT is of significant prognostic relevance. Hispanic patients with acute PE should routinely undergo compression doppler ultrasonography (CDUS) of the lower extremities.

Patients with COVID-19 are at an increased risk for venous thromboembolism (VTE). With the advent of vaccinations and novel treatments from 2020 through 2022, the landscape of COVID-19 has evolved. Notably, the effects of such interventions on the outcomes of COVID-19-associated VTE have not been thoroughly examined. Data from the RIETE registry were analyzed to evaluate 90-day VTE-related outcomes (all-cause mortality, major bleeding, and VTE recurrences) in patients with COVID-19-associated VTE. We compared the periods before and after the widespread introduction of COVID-19 vaccines: March to December 2020 (pre-vaccine period) and March 2021 to December 2022 (post-vaccine period). Statistical analysis included mixed-effects parametric survival-time models. Among 1,620 patients with COVID-19-associated VTE, most (74.1%) were identified during 2020 period. The analysis revealed a more than two-fold increase in the risk of death within 90 days (adjusted hazard ratio [HR]: 2.27; 95% confidence interval, CI: 1.18-4.38) and major bleeding (adjusted HR: 2.91; 95%CI: 1.08-7.84) for patients from the 2020 period compared to those from the 2021-2022 period. Inpatient subgroup analysis confirmed the observed mortality differences. The frequency of recurrent VTE was low (1.1 vs. 0.7%, respectively), and did not show significant variation between the two periods. Our research provides a comparative perspective on the clinical outcomes of COVID-19-associated VTE before and after the introduction of vaccines. Our findings reveal a significant decrease in the incidence of 90-day mortality and major bleeding in patients with COVID-19-associated VTE in the 2021-2022 period.

Venous thromboembolism is a frequent complication of acute hospital care, and this extends to inpatient rehabilitation. The timely use of appropriate thromboprophylaxis in patients who are at risk is a strong, evidence-based patient safety priority that has reduced clinically important venous thromboembolism, associated mortality and costs of care. While there has been extensive research on optimal approaches to venous thromboembolism prophylaxis in acute care, there is a paucity of high-quality evidence specific to patients in the rehabilitation setting, and there are no clinical practice guidelines that make recommendations for (or against) thromboprophylaxis across the broad spectrum of rehabilitation patients. Herein, we provide an evidence-informed review of the topic with practice suggestions. We conducted a series of literature searches to assess the risks of venous thromboembolism and its prevention related to inpatient rehabilitation as well as in major rehabilitation subgroups. Mobilization alone does not eliminate the risk of venous thromboembolism after another thrombotic insult. Low molecular weight heparins and direct oral anticoagulants are the principal current modalities of thromboprophylaxis. Based on the literature, we make suggestions for venous thromboembolism prevention and include an approach for consideration by rehabilitation units that can be aligned with local practice.

Cirrhosis causes an imbalance in the coagulation pathway and leads to a tendency for both bleeding and clotting. SARS-CoV-2 has been reported to be associated with a hypercoagulable state. This study examines SARS-CoV-2's impact on hemostasis in compensated patients with cirrhosis.

We analyzed the US Collaborative Network, which comprises 63 HCOs in the U.S.A. Compensated cirrhosis patients were split into two groups: SARS-CoV-2-positive and -negative. Patients' baseline characteristics were used in a 1:1 propensity score-matched module to create comparable cohorts. We compared the risk of portal vein thrombosis (PVT), deep venous thrombosis (DVT), and pulmonary embolism (PE) at 6 months, and 1 and 3 years.

Of 330,521 patients, 27% tested positive and 73% remained negative. After PSM, both cohorts included 74,738 patients. Patients with SARS-CoV-2 had a higher rate of PVT compared to those without at 6 months (0.63% vs 0.5%, p < 0.05), 1 year (0.8% vs 0.6%, p < 0.05), and 3 years (1% vs. 0.7%, p < 0.05), a higher rate of DVT at 6 months (0.8% vs. 0.4%, p < 0.05), 1 year (1% vs. 0.5%, p < 0.05), and 3 years (1.4% vs. 0.8%, p < 0.05), and a higher rate of PE at 6 months (0.6% vs. 0.3%, p < 0.05), 1 year (0.7% vs. 0.4%, p < 0.05), and 3 years (1% vs. 0.6%, p < 0.05).

The presence of SARS-CoV-2 infection in patients with compensated cirrhosis was associated with a higher rate of PVT, DVT, and PE at 6 months, and 1 and 3 years.

SARS-CoV-2 is a systemic disease that affects endothelial function and leads to coagulation disorders, increasing the risk of mortality. Blood levels of endothelial biomarkers such as Von Willebrand Factor (VWF), Thrombomodulin or Blood Dendritic Cell Antigen-3 (BDCA3), and uUokinase (uPA) increase in patients with severe disease and can be prognostic indicators for mortality. Therefore, the aim of this study was to determine the effect of VWF, BDCA3, and uPA levels on mortality.

From May 2020 to January 2021, we studied a prospective cohort of hospitalized adult patients with polymerase chain reaction (PCR)-confirmed COVID-19 with a SaO2 ≤ 93% and a PaO2/FiO2 ratio < 300. In-hospital survival was evaluated from admission to death or to a maximum of 60 days of follow-up with Kaplan-Meier survival curves and Cox proportional hazard models as independent predictor measures of endothelial dysfunction.

We recruited a total of 165 subjects (73% men) with a median age of 57.3 ± 12.9 years. The most common comorbidities were obesity (39.7%), hypertension (35.4%) and diabetes (30.3%). Endothelial biomarkers were increased in non-survivors compared to survivors. According to the multivariate Cox proportional hazard model, those with an elevated VWF concentration ≥ 4870 pg/ml had a hazard ratio (HR) of 4.06 (95% CI: 1.32-12.5) compared to those with a lower VWF concentration adjusted for age, cerebrovascular events, enoxaparin dose, lactate dehydrogenase (LDH) level, and bilirubin level. uPA and BDCA3 also increased mortality in patients with levels ≥ 460 pg/ml and ≥ 3600 pg/ml, respectively.

The risk of mortality in those with elevated levels of endothelial biomarkers was observable in this study.

Classical pulmonary thromboembolism (TE) and local pulmonary thrombosis (PT) have been suggested as mechanisms of thrombosis in COVID-19. However, robust evidence is still lacking because this was mainly based on retrospective studies, in which patients were included when TE was suspected.

All patients with COVID-19 pneumonia underwent computed tomography and pulmonary angiography in a prospective study. The main objective was to determine the number and percentage of thrombi surrounded by lung opacification (TSO) in each patient, as well as their relationship with percentage of lung involvement (TLI), to distinguish classical TE (with a random location of thrombi that should correspond to a percentage of TSO equivalent to the TLI) from PT. We determined TLI by artificial intelligence. Analyses at patient level (TLI and percentage of TSO) and at thrombi level (TLI and TSO) were performed.

We diagnosed TE in 70 out of 184 patients. Three (2-8) thrombi/patient were detected. The percentage of TSO was 100% (75-100) per patient, and TLI was 19.9% (4.6-35.2). Sixty-five patients (92.9%) were above the random scenario with higher percentage of TSO than TLI. Most thrombi were TSO (n = 299, 75.1%). When evaluating by TLI (<10%, 10%-20%, 20%-30% and >30%), percentage of TSO was higher in most groups. Thrombi were mainly in subsegmental/segmental arteries, and percentage of TSO was higher in all locations.

Thrombi in COVID-19 were found within lung opacities in a higher percentage than lung involvement, regardless of TLI and clot location, supporting the hypothesis of local PT rather than "classic TE".

Spontaneous echo contrast (SEC) is a vascular ultrasound finding associated with increased thromboembolism risk. However, identification requires expert determination and clinician time to report. We developed a deep learning model that can automatically identify SEC. Our model can be applied retrospectively without deviating from routine clinical practice. The retrospective nature of our model means future works could scan archival data to opportunistically correlate SEC findings with documented clinical outcomes.

We curated a data set of 801 archival acquisitions along the femoral vein from 201 patients. We used a multisequence convolutional neural network (CNN) with ResNetv2 backbone and visualized keyframe importance using soft attention. We evaluated SEC prediction performance using an 80/20 train/test split. We report receiver operating characteristic area under the curve (ROC-AUC), along with the Youden threshold-associated sensitivity, specificity, F1 score, true negative, false negative, false positive and true positive.

Using soft attention, we can identify SEC with an AUC of 0.74, sensitivity of 0.73 and specificity of 0.68. Without soft attention, our model achieves an AUC of 0.69, sensitivity of 0.71 and specificity of 0.60. Additionally, we provide attention visualizations and note that our model assigns higher attention score to ultrasound frames containing more vessel lumen.

Our multisequence CNN model can identify the presence of SEC from ultrasound keyframes with an AUC of 0.74, which could enable screening applications and enable more SEC data discovery. The model does not require the expert intervention or additional clinician reporting time that are currently significant barriers to SEC adoption. Model and processed data sets are publicly available at https://github.com/Ouwen/automatic-spontaneous-echo-contrast.

COVID-19 has disproportionately affected racialized populations, with particular impact among individuals of Black individuals. However, it is unclear whether disparities in venous thromboembolic (VTE) complications exist between Black individuals and those belonging to other racial groups with confirmed SARS-CoV2 infections.

To summarize the prevalence and moderators associated with VTE among Black COVID-19 patients in minoritized settings, and to compare this to White and Asian COVID-19 patients according to sex, age, and comorbid health conditions (heart failure, cancer, obesity, hypertension).

A systematic search of MEDLINE, Embase, CINAHL and CENTRAL for articles or reports published from inception to February 15, 2023.

Reports on VTE among Black individuals infected with SARS-CoV2, in countries where Black people are considered a minority population group.

Study characteristics and results of eligible studies were independently extracted by 2 pairs of reviewers. VTE prevalence was extracted, and risk of bias was assessed. Prevalence estimates of VTE prevalence among Black individuals with COVID19 in each study were pooled. Where studies provided race-stratified VTE prevalence among COVID19 patients, odds ratios were generated using a random-effects model.

Prevalence of VTE, comprising of deep vein thrombosis and pulmonary embolism.

Ten studies with 66,185 Black individuals reporting the prevalence of COVID-19 associated VTE were included. Weighted median age of included studies was 47.60. Pooled prevalence of COVID-19 associated VTE was 7.2 % (95 % CI, 3.8 % - 11.5 %) among Black individuals. Among individuals with SARS-CoV2 infections, Black population had higher risks of VTE compared to their White (OR = 1.79, [95 % CI 1.28-2.53], p < .001) or Asian (OR = 2.01, [95 % CI, 1.14-3.60], p = .017) counterparts, or patients with other racial identities (OR = 2.01, [95 % CI, 1.39, 2.92]; p < .001).

Black individuals with COVID-19 had substantially higher risk of VTE compared to White or Asian individuals. Given racial disparities in thrombotic disease burden related to COVID-19, medical education, research, and health policy interventions are direly needed to ensure adequate disease awareness among Black individuals, to facilitate appropriate diagnosis and treatment among Black patients with suspected and confirmed VTE, and to advocate for culturally safe VTE prevention strategies, including pre-existing inequalities to the COVID-19 pandemic that persist after the crisis.