Venous thromboembolism in SARS-CoV-2 patients: only a problem in ventilated ICU patients, or is there more to it?

Risk of venous thromboembolism in patients with COVID-19 during 2020; a retrospective cross-sectional study in a Swedish health care system

To establish the impact of COVID-19 on the pre-test probability for VTE in patients with suspected VTE. This was a retrospective, observational, cross-sectional study of patients 18 years and older undergoing diagnostic tests for VTE in an integrated healthcare system covering a population of 465,000 during the calendar year of 2020. We adjusted for risk factors such as age, sex, previous VTE, ongoing anticoagulant treatment, malignancy, Charlson score, ward care, ICU care and wave of COVID-19. In total, 303 of 5041 patients had a positive diagnosis of COVID-19 around the time of investigation. The prevalence of VTE in COVID-positive patients was 10.2% (36/354), 14.7% (473/3219) in COVID-19 negative patients, and 15.6% (399/2589) in patients without a COVID-19 test. A COVID-positive status was not associated with an increased risk for VTE (crude odds ratio 0.64, 95% CI 0.45-0.91, adjusted odds ratio 0.46, 95%CI 0.19-1.16). We found no increased VTE risk in COVID-positive patients. This indicates that COVID-19 status should not influence VTE workup.The study was pre-registered on May 26, 2020 at ClinicalTrials.gov with identifier NCT04400877.

Estimating incidence of venous thromboembolism in COVID-19: Methodological considerations

Background

Coagulation abnormalities and coagulopathy are recognized as consequences of severe acute respiratory syndrome coronavirus 2 infection and the resulting coronavirus disease 2019 (COVID‐19). Specifically, venous thromboembolism (VTE) has been reported as a frequent complication. By May 27, 2021, at least 93 original studies and 25 meta‐analyses investigating VTE incidence in patients with COVID‐19 had been published, showing large heterogeneity in reported VTE incidence ranging from 0% to 85%. This large variation complicates interpretation of individual study results as well as comparisons across studies, for example, to investigate changes in incidence over time, compare subgroups, and perform meta‐analyses.

Objectives

This study sets out to provide an overview of sources of heterogeneity in VTE incidence studies in patients with COVID‐19, illustrated using examples.

Methods

The original studies of three meta‐analyses were screened and a list of sources of heterogeneity that may explain observed heterogeneity across studies was composed.

Results

The sources of heterogeneity in VTE incidence were classified as clinical sources and methodologic sources. Clinical sources of heterogeneity include differences between studies regarding patient characteristics that affect baseline VTE risk and protocols used for VTE testing. Methodologic sources of heterogeneity include differences in VTE inclusion types, data quality, and the methods used for data analysis.

Conclusions

To appreciate reported estimates of VTE incidence in patients with COVID‐19 in relation to its etiology, prevention, and treatment, researchers should unambiguously report about possible clinical and methodological sources of heterogeneity in those estimates. This article provides suggestions for that.

Changes in laboratory value improvement and mortality rates over the course of the pandemic: an international retrospective cohort study of hospitalised patients infected with SARS-CoV-2

OBJECTIVE

To assess changes in international mortality rates and laboratory recovery rates during hospitalisation for patients hospitalised with SARS-CoV-2 between the first wave (1 March to 30 June 2020) and the second wave (1 July 2020 to 31 January 2021) of the COVID-19 pandemic.

DESIGN, SETTING AND PARTICIPANTS

This is a retrospective cohort study of 83 178 hospitalised patients admitted between 7 days before or 14 days after PCR-confirmed SARS-CoV-2 infection within the Consortium for Clinical Characterization of COVID-19 by Electronic Health Record, an international multihealthcare system collaborative of 288 hospitals in the USA and Europe. The laboratory recovery rates and mortality rates over time were compared between the two waves of the pandemic.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was all-cause mortality rate within 28 days after hospitalisation stratified by predicted low, medium and high mortality risk at baseline. The secondary outcome was the average rate of change in laboratory values during the first week of hospitalisation.

RESULTS

Baseline Charlson Comorbidity Index and laboratory values at admission were not significantly different between the first and second waves. The improvement in laboratory values over time was faster in the second wave compared with the first. The average C reactive protein rate of change was -4.72 mg/dL vs -4.14 mg/dL per day (p=0.05). The mortality rates within each risk category significantly decreased over time, with the most substantial decrease in the high-risk group (42.3% in March-April 2020 vs 30.8% in November 2020 to January 2021, p<0.001) and a moderate decrease in the intermediate-risk group (21.5% in March-April 2020 vs 14.3% in November 2020 to January 2021, p<0.001).

CONCLUSIONS

Admission profiles of patients hospitalised with SARS-CoV-2 infection did not differ greatly between the first and second waves of the pandemic, but there were notable differences in laboratory improvement rates during hospitalisation. Mortality risks among patients with similar risk profiles decreased over the course of the pandemic. The improvement in laboratory values and mortality risk was consistent across multiple countries.

Post-COVID-19 hematologic complications: a systematic review

INTRODUCTION

COVID-19 crisis continues around the world. Some patients developed complications after the disease, which have been reported in limited studies. The aim of this study is to comprehensively assess the post-COVID hematologic complications in patients.

AREAS COVERED

We searched PubMed, Scopus and Google Scholar between January 2020 and August 2021 using related keywords. Evaluation of the articles was performed by two independent researchers. The extracted data included number of patients, age, type of hematological complication, duration of follow-up, response to treatment and prognosis.

EXPERT OPINION

Sixty five articles reported post-COVID hematologic complications. The most frequent hematologic complication in COVID-19 patients is thromboembolic events, which often occur in two forms: deep vein thrombosis (DVT) and pulmonary emboli (PE). In a group of patients after the diagnosis of COVID-19, a significant decrease in platelets was observed, which was attributed to the ITP induced by COVID-19. Hemolytic anemia and aplastic anemia have also been reported rarely in patients. Finally, post-COVID hematologic complications appear to go beyond thromboembolic events. Although these complications have been reported rarely, searching for methods to identify susceptible patients and prevent these complications could be the subject of future research.

Increased risk for thromboembolic events from combination of a gynecologic malignancy with severe acute respiratory syndrome coronavirus 2 infection: a case report

PURPOSE

During the severe acute respiratory syndrome coronavirus 2 pandemic, several patient groups are at particular risk. Mortality is higher among cancer patients and may be increased further by thromboembolic events, which are more common in coronavirus 2019 patients according to recent publications. We discuss the association of gynecologic malignancies, Severe acute respiratory syndrome coronavirus 2, and thromboembolism by reporting a case study and summarizing available literature.

CASE REPORT

A 71-year-old Caucasian patient with ovarian cancer receiving first-line chemotherapy was diagnosed with deep vein thrombosis and pulmonary embolism. Routine screening revealed infection with severe acute respiratory syndrome coronavirus 2 in absence of specific symptoms. After uneventful recovery, oncologic treatment could be continued a few weeks later.

METHODS

We performed a systematic review of the literature on PubMed following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. The search included articles ahead of print, published between 1 December 2019 and 1 June 2020. Cross-searches were conducted on all relevant articles.

RESULTS

We identified five articles meeting the defined criteria, including two retrospective studies, a review, a position paper, as well as a letter to the editor.

CONCLUSION

Cancer patients infected with severe acute respiratory syndrome coronavirus 2 have a relatively poor outcome, which may partially be due to a higher rate of thromboembolic events. Thromboprophylaxis is recommended, and scoring systems are helpful in early detection. In cancer patients with severe acute respiratory syndrome coronavirus 2, individual risk for thromboembolic events should be taken into account when considering interruption versus continuation of antitumoral therapy. However, further data and studies are required.

SARS-CoV-2-related and Covid-19 vaccine-induced thromboembolic events: A comparative review

Since the start of the pandemic, thrombotic events have been a well-known and severe complication associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Nevertheless, the initiation of vaccination programs brought another rare yet highly fatal thrombotic event, vaccine-induced immune thrombotic thrombocytopaenia, which has caused extensive debate regarding the safety of vaccines. This review defines the thromboembolic events following infection and vaccination, identifies their risk factors, describes their pathophysiology, and discusses their management, treatment, and prevention.

Evaluation of a patient specific, targeted-intensity pharmacologic thromboprophylaxis protocol in hospitalized patients with COVID-19

Patients with COVID-19 are at higher risk of thrombosis due to the inflammatory nature of their disease. A higher-intensity approach to pharmacologic thromboprophylaxis may be warranted. The objective of this retrospective cohort study was to determine if a patient specific, targeted-intensity pharmacologic thromboprophylaxis protocol incorporating severity of illness, weight, and biomarkers decreased incidence of thrombosis in hospitalized patients with COVID-19. Included patients were hospitalized with COVID-19 and received thromboprophylaxis within 48 h of admission. Exclusion criteria included receipt of therapeutic anticoagulation prior to or within 24 h of admission, history of heparin-induced thrombocytopenia, extracorporeal membrane oxygenation, pregnancy, or incarceration. Per-protocol patients received thromboprophylaxis according to institutional protocol involving escalated doses of anticoagulants based upon severity of illness, total body weight, and biomarker thresholds. The primary outcome was thrombosis. Secondary outcomes included major bleeding, mortality, and identification of risk factors for thrombosis. Of 1189 patients screened, 803 were included in the final analysis. The median age was 54 (42-65) and 446 (55.5%) were male. Patients in the per-protocol group experienced significantly fewer thrombotic events (4.4% vs. 10.7%, p = 0.002), less major bleeding (3.1% vs. 9.6%, p < 0.001), and lower mortality (6.3% vs. 11.8%, p = 0.02) when compared to patients treated off-protocol. Significant predictors of thrombosis included mechanical ventilation and male sex. Post-hoc regression analysis identified mechanical ventilation, major bleeding, and D-dimer ≥ 1500 ng/mL FEU as significant predictors of mortality. A targeted pharmacologic thromboprophylaxis protocol incorporating severity of illness, body weight, and biomarkers appears effective and safe for preventing thrombosis in patients with COVID-19.

SARS-CoV-2 induced coagulopathy and potential role of anticoagulation: Scoping review of literature

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can vary on a spectrum of asymptomatic disease to rarer manifestations like hypercoagulability especially among elderly patients admitted in the intensive care unit (ICU) and those with preexisting comorbidities. The exact mechanism behind this phenomenon is still unclear, however studies have shown an association with elevated cytokines and severe inflammatory response which encompasses this disease. Hypercoagulability can be limited to the lungs, or present as systemic manifestations of arterial and venous thrombosis leading to mortal outcomes. Thus, careful evaluation of risk factors should be performed by physicians and treatment with anticoagulants should be modified accordingly. All Coronavirus Disease 2019 (COVID-19) in-patients should receive thromboprophylactic therapy, with increased dosages administered to patients with increased disease severity or those with a high risk. D-dimer levels and sepsis-induced coagulopathy (SIC) score aid in identifying high risk patients and predicting outcome. This article highlights the pathophysiology behind hypercoagulability, its clinical associations and discusses therapeutic modalities to combat this fatal consequence of SARS-CoV-2.

Isolated thrombosis after COVID-19 vaccination: case series

Background

Data regarding thrombosis after COVID-19 vaccination are scarce.

Methods

Clinical and laboratory data were collected from all patients who developed thrombosis within 4 weeks of receiving the Pfizer or Oxford/AstraZeneca vaccine. None had a COVID-19-positive swab.

Results

Seventeen patients were included, with average age of 48.8 years and equal proportion of females to males. Our data suggest that thrombosis occurred in 1 in 163,000 of all individuals who had received any dose of any type of COVID-19 vaccine: six (1 in 123,000) patients after the first dose of Oxford/AstraZeneca, none after the second dose of Oxford/AstraZeneca, four (1 in 257,000) patients after the first dose of the Pfizer vaccine, and seven (1 in 102,000) patients after the second dose of Pfizer vaccine. Three of 17 patients with thrombosis (17.6%) died.

Conclusions

We believe this report to be one of the earliest in the literature to address the question of whether isolated thrombosis is a possible complication of COVID-19 vaccination.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12185-021-03285-6.

Risk of symptomatic venous thromboembolism in mild and moderate COVID-19: A comparison of two prospective European cohorts

BACKGROUND

Severely ill patients with SARS-CoV-2 have an increased risk of venous thromboembolism (VTE) i.e., deep vein thrombosis and pulmonary embolism. However, the VTE risk in patients with mild and moderate COVID-19, hospitalized or managed at home, remain uncertain. The aims of this study were to assess the rate and the risk factors symptomatic VTE, in patients with mild and moderate COVID-19 and to compare them to a cohort of similar patients without COVID-19.

METHODS

Patients presenting to the emergency department (ED) of participating centers for confirmed or probable mild or moderate COVID-19 and not having acute VTE were included. This COVID-19 cohort was retrospectively compared to a prospective cohort of similar ED patients using propensity score matching. The main outcome was the rate of symptomatic VTE within the 28 days after ED presentation.

RESULTS

A total of 2292 patients were included in the COVID-19 cohort. The 28-day incidence of symptomatic VTE was 1.3% (n = 29/2292, 95%CI: 0.9 to 1.8), 2.3% (n = 20/866, 95%CI: 1.5 to 3.5) in moderate COVID-19 patients and 0.6% (n = 9/1426; 95%CI: 0.3 to 1.2) in mild COVID-19 patients managed as outpatients. An age over 65 years and hospitalization were independent risk factors of VTE. After adjustment, patients in the COVID-19 cohort had an absolute increase in over symptomatic VTE risk of +1.69% (95%CI, 0.88 to 2.51) versus patients in the comparison cohort (n = 1539).

CONCLUSIONS

Patients with moderate COVID-19 presenting to the ED had a high risk of subsequent VTE.

TRIAL REGISTRATION

Ethics committee of the CHU of Angers (N°2020/87).

Thrombosis and Bleeding After Implementation of an Intermediate-Dose Prophylactic Anticoagulation Protocol in ICU Patients With COVID-19: A Multicenter Screening Study

Thrombosis and bleeding after implementation of an intermediate-dose prophylactic anticoagulation protocol in intensive care unit (ICU) patients with coronavirus disease 2019 (COVID-19): a multicenter screening study Background: Venous thromboembolism (VTE) is common among critically ill patients with COVID-19. Information regarding VTE prevalence and bleeding complications after implementation of intermediate-dose prophylactic anticoagulation in such patients is, however, limited. Methods: We performed a prospective, observational study in 6 ICUs in 2 university-affiliated teaching hospitals in Sweden. After implementation of an intermediate-dose prophylactic anticoagulation protocol, we performed ultrasound screening for proximal lower-extremity deep vein thrombosis (DVT) and collected routine computed tomography pulmonary angiography exam results. Results: A total of 100 COVID-19 patients were included from June 21, 2020, through February 18, 2021. During a median follow-up of 120 (IQR, 89-134) days, we found VTE in 37 patients with the majority (78.4%) being diagnosed after ICU arrival. Overall, 20 patients had proximal lower-extremity DVT with 95% being detected on ultrasound screening; 22 patients had pulmonary vascular thrombosis; and 4 patients had venous thrombosis at other sites. A total of 6 patients had both proximal lower-extremity DVT and pulmonary vascular thrombosis. On univariate logistic regression analysis of 14 baseline characteristics, only pre-existing heart failure was associated with VTE (OR 4.67, 95% CI 1.13-19.34). Major and non-major bleeding occurred in 10 and 18 patients, respectively. Conclusions: In our cohort of ICU patients with COVID-19, we observed a high prevalence of VTE and bleeding complications after implementation of intermediate-dose anticoagulation. In approximately half of patients, VTE was identified on screening ultrasound.

Risk of venous thromboembolism in a Swedish healthcare system during the COVID-19 pandemic: A retrospective cross-sectional study

OBJECTIVE

The objective of this study was to investigate the risk and prevalence of venous thromboembolism (VTE) for patients undergoing a diagnostic test for VTE with confirmed COVID-19 infection compared with patients with no COVID-19 infection.

METHODS

This was a retrospective cross-sectional study of patients in an integrated healthcare system in Sweden, covering a population of 465,000, with a diagnostic test for VTE between March 1 and May 31 in the years 2015 to 2020. Risk for VTE with COVID-19 was assessed by logistic regression, adjusting for baseline risk factors.

RESULTS

A total of 8702 patients were included, and 88 of those patients tested positive on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction test. A positive SARS-CoV-2 test did not increase the odds for VTE (odds ratio, 0.97; 95% confidence interval [CI], 0.55-1.74) and did not change when adjusting for sex, previous VTE, previous malignancy, Charlson score, hospital admission, intensive care, or ongoing treatment with anticoagulation (odds ratio, 0.72; 95% CI, 0.16-3.3). The prevalence of VTE was unchanged in 2020 compared with 2015 to 2019 (16.5% vs 16.1%, respectively), and there was no difference in VTE between the SARS-CoV-2 positive, negative, or untested groups in 2020 (15.9%, 17.6%, and 15.7%, respectively; P = 0.85).

CONCLUSIONS

We found no increased prevalence of VTE in the general population compared with previous years and no increased risk of VTE in patients who were SARS-CoV-2 positive, suggesting that SARS-CoV-2 status should not influence VTE workup in the emergency department. The prevalence of VTE was high in patients with SARS-CoV-2 treated in the intensive care unit (ICU), where the suspicion for VTE should remain high.

Venous thromboembolism in COVID-19: A systematic review and meta-analysis

Severe coronavirus disease 2019 (COVID-19) is associated with increased risk of venous thromboembolism events (VTE). This study performed a systematic review in PubMed/EMBASE of studies reporting the prevalence of VTE in patients with COVID-19 who were totally screened/assessed for deep vein thrombosis (DVT) and/or for pulmonary embolism (PE). Among 47 candidate studies (n = 6459; 33 in Europe), 17 studies (n = 3973; weighted age 63.0 years, males 60%, intensive care unit (ICU) 16%) reported the prevalence of PE with a pooled estimate of 32% (95% CI: 25, 40%), and 32 studies (n = 2552; weighted age 62.6 years, males 57%, ICU 49%) reported the prevalence of DVT with a pooled estimate of 27% (95% CI: 21, 34%). A total of 36 studies reported the use of at least prophylactic antithrombotic treatment in the majority of their patients. Meta-regression analysis showed that the prevalence of VTE was higher across studies with a higher percentage of ICU patients and higher study population mean D-dimer values, and lower in studies with mixed dosing of anticoagulation in ⩾ 50% of the population compared to studies with standard prophylactic dosing of anticoagulation in < 50% of the population. The pooled odds ratio for death in patients with COVID-19 and VTE versus those without VTE (17 studies, n = 2882) was 2.1 (95% CI: 1.2, 3.6). Hospitalized patients with severe COVID-19 are at high VTE risk despite prophylactic anticoagulation. Further research should investigate the individualized VTE risk of patients with COVID-19 and the optimal preventive antithrombotic therapy. PROSPERO Registration No.: CRD42020185543.

Can we predict the severe course of COVID-19 - a systematic review and meta-analysis of indicators of clinical outcome?

BACKGROUND

COVID-19 has been reported in over 40million people globally with variable clinical outcomes. In this systematic review and meta-analysis, we assessed demographic, laboratory and clinical indicators as predictors for severe courses of COVID-19.

METHODS

This systematic review was registered at PROSPERO under CRD42020177154. We systematically searched multiple databases (PubMed, Web of Science Core Collection, MedRvix and bioRvix) for publications from December 2019 to May 31st 2020. Random-effects meta-analyses were used to calculate pooled odds ratios and differences of medians between (1) patients admitted to ICU versus non-ICU patients and (2) patients who died versus those who survived. We adapted an existing Cochrane risk-of-bias assessment tool for outcome studies.

RESULTS

Of 6,702 unique citations, we included 88 articles with 69,762 patients. There was concern for bias across all articles included. Age was strongly associated with mortality with a difference of medians (DoM) of 13.15 years (95% confidence interval (CI) 11.37 to 14.94) between those who died and those who survived. We found a clinically relevant difference between non-survivors and survivors for C-reactive protein (CRP; DoM 69.10 mg/L, CI 50.43 to 87.77), lactate dehydrogenase (LDH; DoM 189.49 U/L, CI 155.00 to 223.98), cardiac troponin I (cTnI; DoM 21.88 pg/mL, CI 9.78 to 33.99) and D-Dimer (DoM 1.29mg/L, CI 0.9 to 1.69). Furthermore, cerebrovascular disease was the co-morbidity most strongly associated with mortality (Odds Ratio 3.45, CI 2.42 to 4.91) and ICU admission (Odds Ratio 5.88, CI 2.35 to 14.73).

DISCUSSION

This comprehensive meta-analysis found age, cerebrovascular disease, CRP, LDH and cTnI to be the most important risk-factors that predict severe COVID-19 outcomes and will inform clinical scores to support early decision-making.

Macrovascular Thrombotic Events in a Mayo Clinic Enterprise-Wide Sample of Hospitalized COVID-19-Positive Compared With COVID-19-Negative Patients

OBJECTIVE

To determine the difference in the rate of thromboembolic complications between hospitalized coronavirus disease 2019 (COVID-19)-positive compared with COVID-19-negative patients.

PATIENTS AND METHODS

Adult patients hospitalized from January 1, 2020, through May 8, 2020, who had COVID-19 testing by polymerase chain reaction assay were identified through electronic health records across multiple hospitals in the Mayo Clinic enterprise. Thrombotic outcomes (venous and arterial) were identified from the hospital problem list.

RESULTS

We identified 3790 hospitalized patients with COVID-19 testing across 19 hospitals, 102 of whom had positive test results. The median age was lower in the COVID-positive patients (62 vs 67 years; P=.03). The median duration of hospitalization was longer in COVID-positive patients (8.5 vs 4 days; P<.001) and more required intensive care unit care (56.9% [58 of 102] vs 26.8% [987 of 3688]; P<.001). Comorbidities, including atrial fibrillation/flutter, heart failure, chronic kidney disease, and malignancy, were observed less frequently with COVID-positive admissions. Any venous thromboembolism was identified in 2.9% of COVID-positive patients (3 of 102) and 4.6% of COVID-negative patients (168 of 3688). The frequency of venous and arterial events was not different between the groups. The unadjusted odds ratio (OR) for COVID-positive-patients for any venous thromboembolism was 0.63 (95% CI, 0.19 to 2.02). A multivariable logistic regression model evaluated death within 30 days of hospital discharge; neither COVID positivity (adjusted OR, 1.12; 95% CI, 0.54 to 2.34) nor thromboembolism (adjusted OR, 0.90; 95% CI, 0.60 to 1.32) was associated with death.

CONCLUSION

Early experience in patients with COVID-19 across multiple academic and regional hospitals representing different US regions demonstrates a lower than previously reported incidence of thrombotic events. This incidence was not higher than a contemporary COVID-negative hospitalized comparator.

Albumin Infusion in Critically Ill COVID-19 Patients: Hemodilution and Anticoagulation

Hypercoagulation is one of the major risk factors for ICU treatment, mechanical ventilation, and death in critically ill patients infected with SARS-CoV-2. At the same time, hypoalbuminemia is one risk factor in such patients, independent of age and comorbidities. Especially in patients with severe SARS-CoV-2-infection, albumin infusion may be essential to improve hemodynamics and to reduce the plasma level of the main marker of thromboembolism, namely, the D-dimer plasma level, as suggested by a recent report. Albumin is responsible for 80% of the oncotic pressure in the vessels. This is necessary to keep enough water within the systemic circulatory system and for the maintenance of sufficient blood pressure, as well as for sufficient blood supply for vital organs like the brain, lungs, heart, and kidney. The liver reacts to a decrease in oncotic pressure with an increase in albumin synthesis. This is normally possible through the use of amino acids from the proteins introduced with the nutrients reaching the portal blood. If these are not sufficiently provided with the diet, amino acids are delivered to the liver from muscular proteins by systemic circulation. The liver is also the source of coagulation proteins, such as fibrinogen, fibronectin, and most of the v WF VIII, which are physiological components of the extracellular matrix of the vessel wall. While albumin is the main negative acute-phase protein, fibrinogen, fibronectin, and v WF VIII are positive acute-phase proteins. Acute illnesses cause the activation of defense mechanisms (acute-phase reaction) that may lead to an increase of fibrinolysis and an increase of plasma level of fibrinogen breakdown products, mainly fibrin and D-dimer. The measurement of the plasma level of the D-dimer has been used as a marker for venous thromboembolism, where a fourfold increase of the D-dimer plasma level was used as a negative prognostic marker in critically ill SARS-CoV-2 hospitalized patients. Increased fibrinolysis can take place in ischemic peripheral sites, where the mentioned coagulation proteins can become part of the provisional clot (e.g., in the lungs). Although critically ill SARS-CoV-2-infected patients are considered septic shock patients, albumin infusions have not been considered for hemodynamic resuscitation and as anticoagulants. The role of coagulation factors as provisional components of the extracellular matrix in case of generalized peripheral ischemia due to hypoalbuminemia and hypovolemia is discussed in this review.

Clinical Features of COVID-19 Patients With Venous Thromboembolism

This study aimed to assess the clinical features of coronavirus disease 2019 (COVID-19) patients with VTE, to help develop preventive measures for venous thromboembolism (VTE in COVID-19) cases. COVID-19 patients admitted to Henan Provincial People’s Hospital were retrospectively analyzed, including 23, 4 and 8 cases with mild to moderate, severe and critical symptoms, respectively. VTE incidence, age at onset, relevant laboratory parameters and prognosis were analyzed. Overall, VTE incidence in the 35 patients was 20.0%, occurring in severe (n = 1) and critical (n = 6) cases. D-dimer showed statistical significance in laboratory examination, representing except a diagnostic index and especial can be a prognostic factor in VTE among COVID-19 patients. Severe and critical COVID-19 cases had significantly reduced platelet counts, with a risk of hemorrhage. During treatment, the risk of both hemorrhage and thrombosis should be considered. VTE occurs in COVID-19 cases, affecting individuals with severe and critical symptoms. Significant D-dimer increase is of great significance in the risk assessment of death in critical cases of COVID-19. Appropriate measures should be taken to prevent VTE during treatment.

Viral Respiratory Pathogens and Lung Injury

Several viruses target the human respiratory tract, causing different clinical manifestations spanning from mild upper airway involvement to life-threatening acute respiratory distress syndrome (ARDS). As dramatically evident in the ongoing SARS-CoV-2 pandemic, the clinical picture is not always easily predictable due to the combined effect of direct viral and indirect patient-specific immune-mediated damage. In this review, we discuss the main RNA (orthomyxoviruses, paramyxoviruses, and coronaviruses) and DNA (adenoviruses, herpesviruses, and bocaviruses) viruses with respiratory tropism and their mechanisms of direct and indirect cell damage. We analyze the thin line existing between a protective immune response, capable of limiting viral replication, and an unbalanced, dysregulated immune activation often leading to the most severe complication. Our comprehension of the molecular mechanisms involved is increasing and this should pave the way for the development and clinical use of new tailored immune-based antiviral strategies.

Prevalence of Venous Thromboembolism in Critically Ill Patients With Coronavirus Disease 2019: A Meta-Analysis

Background: Accumulating evidence suggests that coronavirus disease 2019 (COVID-19) is associated with hypercoagulative status, particularly for critically ill patients in the intensive care unit. However, the prevalence of venous thromboembolism (VTE) in these patients under routine prophylactic anticoagulation remains unknown. A meta-analysis was performed to evaluate the prevalence of VTE in these patients by pooling the results of these observational studies. Methods: Observational studies that reported the prevalence of VTE in critically ill patients with COVID-19 were identified by searching the PubMed and Embase databases. A random-effect model was used to pool the results by incorporating the potential heterogeneity. Results: A total of 19 studies with 1,599 patients were included. The pooled results revealed that the prevalence of VTE, deep venous thrombosis (DVT), and pulmonary embolism (PE) in critically ill patients with COVID-19 was 28.4% [95% confidence interval (CI): 20.0-36.8%], 25.6% (95% CI: 17.8-33.4%), and 16.4% (95% CI: 10.1-22.7%), respectively. Limited to studies, in which all patients received routine prophylactic anticoagulation, and the prevalence for VTE, DVT, and PE was 30.1% (95% CI: 19.4-40.8%), 27.2% (95% CI: 16.5-37.9%), and 18.3% (95% CI: 9.8%-26.7%), respectively. The prevalence of DVT was higher in studies with routine screening for all patients, when compared to studies with screening only in clinically suspected patients (47.5% vs. 15.1%, P < 0.001). Conclusion: Critically ill patients with COVID-19 have a high prevalence of VTE, despite the use of present routine prophylactic anticoagulation.

Thrombotic complications in 2928 patients with COVID-19 treated in intensive care: a systematic review

A prothrombotic state is reported with severe COVID-19 infection, which can manifest in venous and arterial thrombotic events. Coagulopathy is reflective of more severe disease and anticoagulant thromboprophylaxis is recommended in hospitalized patients. However, the prevalence of thrombosis on the intensive care unit (ICU) remains unclear, including whether this is sufficiently addressed by conventional anticoagulant thromboprophylaxis. We aimed to identify the rate of thrombotic complications in ICU-treated patients with COVID-19, to inform recommendations for diagnosis and management. A systematic review was conducted to assess the incidence of thrombotic complications in ICU-treated patients with COVID-19. Observational studies and registries reporting thrombotic complications in ICU-treated patients were included. Information extracted included patient demographics, use of thromboprophylaxis or anticoagulation, method of identifying thrombotic complications, and reported patient outcomes. In 28 studies including 2928 patients, thrombotic complications occurred in 34% of ICU-managed patients, with deep venous thrombosis reported in 16.1% and pulmonary embolism in 12.6% of patients, despite anticoagulant thromboprophylaxis, and were associated with high mortality. Studies adopting systematic screening for venous thrombosis with Duplex ultrasound reported a significantly higher incidence of venous thrombosis compared to those relying on clinical suspicion (56.3% vs. 11.0%, p < 0.001). Despite thromboprophylaxis, there is a very high incidence of thrombotic complications in patients with COVID-19 on the ICU. Systematic screening identifies many thrombotic complications that would be missed by relying on clinical suspicion and should be employed, with consideration given to increased dose anticoagulant thromboprophylaxis, whilst awaiting results of prospective trials of anticoagulation in this cohort.

Proximal deep vein thrombosis and pulmonary embolism in COVID-19 patients: a systematic review and meta-analysis

BACKGROUND

COVID-19 appears to be associated with a high risk of venous thromboembolism (VTE). We aimed to systematically review and meta-analyze the risk of clinically relevant VTE in patients hospitalized for COVID-19.

METHODS

This meta-analysis included original articles in English published from January 1st, 2020 to June 15th, 2020 in Pubmed/MEDLINE, Embase, Web of science, and Cochrane. Outcomes were major VTE, defined as any objectively diagnosed pulmonary embolism (PE) and/or proximal deep vein thrombosis (DVT). Primary analysis estimated the risk of VTE, stratified by acutely and critically ill inpatients. Secondary analyses explored the separate risk of proximal DVT and of PE; the risk of major VTE stratified by screening and by type of anticoagulation.

RESULTS

In 33 studies (n = 4009 inpatients) with heterogeneous thrombotic risk factors, VTE incidence was 9% (95%CI 5-13%, I2 = 92.5) overall, and 21% (95%CI 14-28%, I2 = 87.6%) for patients hospitalized in the ICU. Proximal lower limb DVT incidence was 3% (95%CI 1-5%, I2 = 87.0%) and 8% (95%CI 3-14%, I2 = 87.6%), respectively. PE incidence was 8% (95%CI 4-13%, I2 = 92.1%) and 17% (95%CI 11-25%, I2 = 89.3%), respectively. Screening and absence of anticoagulation were associated with a higher VTE incidence. When restricting to medically ill inpatients, the VTE incidence was 2% (95%CI 0-6%).

CONCLUSIONS

The risk of major VTE among COVID-19 inpatients is high but varies greatly with severity of the disease. These findings reinforce the need for the use of thromboprophylaxis in all COVID-19 inpatients and for clinical trials testing different thromboprophylaxis regimens in subgroups of COVID-19 inpatients.

TRIAL REGISTRATION

The review protocol was registered in PROSPERO International Prospective Register of Systematic Reviews ( CRD42020193369 ).

Risk of Clinically Relevant Venous Thromboembolism in Critically Ill Patients With COVID-19: A Systematic Review and Meta-Analysis

Background: Early during the course of the ongoing COVID-19 pandemic, reports suggested alarmingly high incidences for thromboembolic events in critically ill patients with COVID-19. However, the clinical relevance of these events was not reported in several studies. Additionally, more recent research showed contradictory results and suggested substantially lower rates of venous thromboembolism. Thus, the aim of the present study was to summarize evidence on the incidence of clinically relevant venous thromboembolism (VTE)—defined as VTE excluding isolated subsegmental pulmonary embolism (PE) and distal deep vein thrombosis (DVT)—in adult critically ill patients with COVID-19.

Methods: We performed a systematic review of studies reporting the incidence of clinically relevant PE and/or DVT in critically ill patients with COVID-19. Scientific reports published in the English language between January and October 2020 were included. We conducted a random-effects model meta-analysis to calculate incidence estimates of clinically relevant VTE and bleeding events. We also performed exploratory meta-regression and subgroup analyses of different diagnostic approaches and additional factors that possibly influenced the incidence of these outcomes.

Results: Fifty-four articles (5,400 patients) fulfilled the predefined inclusion criteria, of which 41 had a high risk of bias. The majority of included patients were male, > 60 years, and overweight. Twenty-one studies reported the use of prophylactic doses of heparin. Pooled incidences for clinically relevant PE were estimated at 8% (95% CI, 4–11%), for proximal DVT at 14% (95% CI, 9–20%), and—after exclusion of studies with a high risk of bias—for the composite outcome of VTE at 18% (95% CI, 13–24%). Clinically relevant bleeding occurred at a rate of 6% (95% CI, 2–9%).

Conclusions: We summarized currently available data on the rate of clinically relevant VTE in critically ill patients with COVID-19. Pooled incidence estimates were lower than those reported by previous review articles. In the absence of evidence-based anticoagulation guidelines for critically ill patients with COVID-19, the results of our study provide clinically important information for an individual risk-benefit assessment in this context.

Registration: The study protocol was prospectively registered in PROSPERO on June 22, 2020 (CRD42020193353; https://www.crd.york.ac.uk/prospero).

Systematic review and meta-analysis of the prevalence of venous thromboembolic events in novel coronavirus disease-2019 patients

BACKGROUND

Emerging clinical evidence has shown that patients with the novel coronavirus disease-2019 (COVID-19) have complications that include venous thromboembolism (VTE), consisting of deep vein thrombosis (DVT) and pulmonary embolism (PE). The prevalence of VTE in patients hospitalized with COVID-19 is unclear.

METHODS

Eligible studies on COVID-19 were collected from PubMed, Web of Science, and Embase. Patient characteristics and information were extracted for three categories of patients: consecutive, ICU, and non-ICU group. All PEs and DVTs were diagnosed by computed tomographic pulmonary arteriography and duplex ultrasound examination, respectively. A subgroup analysis of testing strategies in ICU and non-ICU patients for PE and DVT was also performed.

RESULTS

Forty clinical studies involving 7966 patients hospitalized with COVID-19 were included. Pooled VTE prevalence was 13% in consecutive patients (95% confidence interval [CI], 0.05-0.24; I2 = 97%), 7% in non-ICU patients (95% CI, 0.01-0.18; I2 = 93%), and 31% in ICU patients (95% CI, 0.22-0.42; I2 = 91%). ICU patients had the highest prevalence of PE among the three groups (17% [95% CI, 0.12-0.23] vs 8% in consecutive patients [95% CI, 0.04-0.13], 4% in non-ICU patients [95% CI, 0.01-0.08]). ICU patients also had the highest DVT prevalence (25% [95% CI, 0.14-0.37] vs 7% in consecutive patients [95% CI, 0.03-0.14], and 7% in non-ICU [95% CI, 0.02-0.14]). The subgroup analysis showed a three-fold improvement in the PE and DVT detection rates in both ICU and non-ICU patients with COVID-19 when the screening test for VTE was applied. In the settings of screening tests for VTE, ICU patients have a significantly higher prevalence of PE (37% vs 10%; P < .0001) and DVT (40% vs 12%; P = .0065) compared with non-ICU patients.

CONCLUSIONS

VTE is common in patients hospitalized with COVID-19, especially among ICU patients. Screening tests for PE and DVT may significantly improve detection rates in both ICU and non-ICU patients with COVID-19 than tests based on clinical suspicion.

Incidence of VTE and Bleeding Among Hospitalized Patients With Coronavirus Disease 2019: A Systematic Review and Meta-analysis

BACKGROUND

Individual studies have reported widely variable rates for VTE and bleeding among hospitalized patients with coronavirus disease 2019 (COVID-19).

RESEARCH QUESTION

What is the incidence of VTE and bleeding among hospitalized patients with COVID-19?

METHODS

In this systematic review and meta-analysis, 15 standard sources and COVID-19-specific sources were searched between January 1, 2020, and July 31, 2020, with no restriction according to language. Incidence estimates were pooled by using random effects meta-analyses. Heterogeneity was evaluated by using the I² statistic, and publication bias was assessed by using the Begg and Egger tests.

RESULTS

The pooled incidence was 17.0% (95% CI, 13.4-20.9) for VTE, 12.1% (95% CI, 8.4-16.4) for DVT, 7.1% (95% CI, 5.3-9.1) for pulmonary embolism (PE), 7.8% (95% CI, 2.6-15.3) for bleeding, and 3.9% (95% CI, 1.2-7.9) for major bleeding. In subgroup meta-analyses, the incidence of VTE was higher when assessed according to screening (33.1% vs 9.8% by clinical diagnosis), among patients in the ICU (27.9% vs 7.1% in the ward), in prospective studies (25.5% vs 12.4% in retrospective studies), and with the inclusion of catheter-associated thrombosis/isolated distal DVTs and isolated subsegmental PEs. The highest pooled incidence estimate of bleeding was reported for patients receiving intermediate- or full-dose anticoagulation (21.4%) and the lowest in the only prospective study that assessed bleeding events (2.7%).

INTERPRETATION

Among hospitalized patients with COVID-19, the overall estimated pooled incidence of VTE was 17.0%, with higher rates with routine screening, inclusion of distal DVT, and subsegmental PE, in critically ill patients and in prospective studies. Bleeding events were observed in 7.8% of patients and were sensitive to use of escalated doses of anticoagulants and nature of data collection. Additional studies are required to ascertain the significance of various thrombotic events and to identify strategies to improve patient outcomes.

TRIAL REGISTRY

PROSPERO; No.: CRD42020198864; URL: https://www.crd.york.ac.uk/prospero/.

COVID-19 With Preexisting Hypercoagulability Digestive Disease

The outbreak of coronavirus disease of 2019 (COVID-19) has become a global public health and economic crisis. The advent of hypercoagulability and thrombotic complications can substantially influence the prognosis of COVID-19 patients. In this review, we elaborate on the clinical findings, potential underlying pathogenesis, and therapeutic strategy of hypercoagulability and thromboembolism in COVID-19, particularly focusing on the COVID-19 patients with preexisting digestive hypercoagulability disease.

Prevalence of Venous Thromboembolism in Critically Ill COVID-19 Patients: Systematic Review and Meta-Analysis

Background: Recent studies revealed a high prevalence of venous thromboembolism (VTE) events in coronavirus disease 2019 (COVID-19) patients, especially in those who are critically ill. Available studies report varying prevalence rates. Hence, the exact prevalence remains uncertain. Moreover, there is an ongoing debate regarding the appropriate dosage of thromboprophylaxis. Methods: We performed a systematic review and proportion meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched PubMed and EMBASE for studies exploring the prevalence of VTE in critically ill COVID-19 patients till 25/07/2020. We pooled the proportion of VTE. Additionally, in a subgroup analysis, we pooled VTE events detected by systematic screening. Finally, in an exploratory analysis, we compared the odds of VTE in patients on prophylactic compared with therapeutic anticoagulation. Results: The review comprised 24 studies and over 2,500 patients. The pooled proportion of VTE prevalence was 0.31 [95% confidence interval (CI) 0.24, 0.39; I 2 94%], of VTE utilizing systematic screening was 0.48 (95% CI 0.33, 0.63; I 2 91%), of deep venous thrombosis was 0.23 (95% CI 0.14, 0.32; I 2 96%), and of pulmonary embolism was 0.14 (95% CI 0.09, 0.20; I 2 90%). Exploratory analysis of few studies, utilizing systematic screening, VTE risk increased significantly with prophylactic, compared with therapeutic anticoagulation [odds ratio (OR) 5.45; 95% CI 1.90, 15.57; I 2 0%]. Discussion: Our review revealed a high prevalence of VTE in critically ill COVID-19 patients. Almost 50% of patients had VTE detected by systematic screening. Higher thromboprophylaxis dosages may reduce VTE burden in this patient's cohort compared with standard prophylactic anticoagulation; however, this is to be ascertained by ongoing randomized controlled trials.

Pharmacologic Thromboprophylaxis and Thrombosis in Hospitalized Patients with COVID-19: A Pooled Analysis

BACKGROUND

 Coronavirus disease 2019 (COVID-19) increases thrombosis in hospitalized patients prompting adoption of different thromboprophylaxis strategies. Safety and efficacy of escalated-dose pharmacologic thromboprophylaxis are not established.

OBJECTIVES

 To determine the pooled incidence of thrombosis/bleeding in hospitalized patients with COVID-19 for standard-dose, intermediate-dose, therapeutic anticoagulation, and no pharmacologic thromboprophylaxis.

METHODS

 MEDLINE, EMBASE, and Cochrane CENTRAL were searched up to August 29, 2020 for studies reporting pharmacologic thromboprophylaxis and thrombosis or bleeding. Pooled event rates were calculated using a random-effects model.

RESULTS

 Thirty-five observational studies were included. The pooled incidence rates of total venous thromboembolism (N = 4,685) were: no prophylaxis 41.9% (95% confidence interval [CI]: 28.1-57.2, I 2 = 76%), standard-dose prophylaxis 19.8% (95% CI: 13.2-28.6, I 2 = 95%), intermediate-dose prophylaxis 11.9% (95% CI: 4.3-28.6, I 2 = 91%), and therapeutic-dose anticoagulants 10.5% (95% CI: 4.2-23.8, I 2 = 82%, p = 0.003). The pooled incidence rates of arterial thrombosis (N = 1,464) were: no prophylaxis 11.3% (95% CI: 5.2-23.0, I 2 = 0%), standard-dose prophylaxis 2.5% (95% CI: 1.4-4.3, I 2 = 45%), intermediate-dose prophylaxis 2.1% (95% CI: 0.5-7.7, I 2 = 45%), and therapeutic-dose anticoagulants 1.3% (95% CI: 0.2-8.8, I 2 = 0, p = 0.009). The pooled bleeding event rates (N = 6,393) were nonsignificantly higher in therapeutic-dose anticoagulants compared with standard-dose prophylaxis, (6.3 vs. 1.7%, p = 0.083).

CONCLUSION

 Thrombosis rates were lower in hospitalized COVID-19 patients who received pharmacologic thromboprophylaxis. Thrombosis and bleeding rates for patients receiving intermediate-dose thromboprophylaxis or therapeutic anticoagulation were similar to those who received standard-dose pharmacologic thromboprophylaxis.

Clinical Characteristics, Treatment, and Outcomes of Critically Ill Patients With COVID-19: A Scoping Review

A growing number of studies on coronavirus disease 2019 (COVID-19) are becoming available, but a synthesis of available data focusing on the critically ill population has not been conducted. We performed a scoping review to synthesize clinical characteristics, treatment, and clinical outcomes among critically ill patients with COVID-19. Between January 1, 2020, and May 15, 2020, we identified high-quality clinical studies describing critically ill patients with a sample size of greater than 20 patients by performing daily searches of the World Health Organization and LitCovid databases on COVID-19. Two reviewers independently reviewed all abstracts (2785 unique articles), full text (218 articles), and abstracted data (92 studies). The 92 studies included 61 from Asia, 16 from Europe, 10 from North and South America, and 5 multinational studies. Notable similarities among critically ill populations across all regions included a higher proportion of older males infected and with severe illness, high frequency of comorbidities (hypertension, diabetes, and cardiovascular disease), abnormal chest imaging findings, and death secondary to respiratory failure. Differences in regions included newly identified complications (eg, pulmonary embolism) and epidemiological risk factors (eg, obesity), less chest computed tomography performed, and increased use of invasive mechanical ventilation (70% to 100% vs 15% to 47% of intensive care unit patients) in Europe and the United States compared with Asia. Future research directions should include proof-of-mechanism studies to better understand organ injuries and large-scale collaborative clinical studies to evaluate the efficacy and safety of antivirals, antibiotics, interleukin 6 receptor blockers, and interferon. The current established predictive models require further verification in other regions outside China.

Venous thromboembolism in patients with COVID-19: Systematic review and meta-analysis

BACKGROUND

Venous thromboembolism (VTE) may complicate the course of Coronavirus Disease 2019 (COVID-19).

OBJECTIVES

To evaluate the incidence of VTE in patients with COVID-19.

METHODS

MEDLINE, EMBASE, and PubMed were searched up to 24th June 2020 for studies that evaluated the incidence of VTE, including pulmonary embolism (PE) and/or deep vein thrombosis (DVT), in patients with COVID-19. Pooled proportions with corresponding 95% confidence intervals (CI) and prediction intervals (PI) were calculated by random-effect meta-analysis.

RESULTS

3487 patients from 30 studies were included. Based on very low-quality evidence due to heterogeneity and risk of bias, the incidence of VTE was 26% (95% PI, 6%-66%). PE with or without DVT occurred in 12% of patients (95% PI, 2%-46%) and DVT alone in 14% (95% PI, 1%-75%). Studies using standard algorithms for clinically suspected VTE reported PE in 13% of patients (95% PI, 2%-57%) and DVT in 6% (95% PI, 0%-60%), compared to 11% (95% PI, 2%-46%) and 24% (95% PI, 2%-85%) in studies using other diagnostic strategies or patient sampling. In patients admitted to intensive care units, VTE occurred in 24% (95% PI, 5%-66%), PE in 19% (95% PI, 6%-47%), and DVT alone in 7% (95% PI, 0%-69%). Corresponding values in general wards were respectively 9% (95% PI, 0%-94%), 4% (95% PI, 0%-100%), and 7% (95% CI, 1%-49%).

CONCLUSIONS

VTE represents a frequent complication in hospitalized COVID-19 patients and often occurs as PE. The threshold for clinical suspicion should be low to trigger prompt diagnostic testing.

Incidence of acute pulmonary embolism in COVID-19 patients: Systematic review and meta-analysis

BACKGROUND

Acute pulmonary embolism (PE) has been described as a frequent and prognostically relevant complication of COVID-19 infection.

AIM

We performed a systematic review and meta-analysis of the in-hospital incidence of acute PE among COVID-19 patients based on studies published within four months of COVID-19 outbreak.

MATERIAL AND METHODS

Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in abstracting data and assessing validity. We searched Medline, Scopus and Web of Science to locate all articles published up to August 1, 2020 reporting the incidence of acute PE (or lung thrombosis) in COVID-19 patients. The pooled in-hospital incidence of acute PE among COVID-19 patients was calculated using a random effects model and presenting the related 95% confidence interval (CI). Statistical heterogeneity was measured using the Higgins I² statistic.

RESULTS

We analysed data from 7178 COVID-19 patients [mean age 60.4 years] included in twenty-three studies. Among patients hospitalized in general wards and intensive care unit (ICU), the pooled in-hospital incidence of PE (or lung thrombosis) was 14.7% of cases (95% CI: 9.9-21.3%, I²=95.0%, p<0.0001) and 23.4% (95% CI:16.7-31.8%, I2=88.7%, p<0.0001), respectively. Segmental/sub-segmental pulmonary arteries were more frequently involved compared to main/lobar arteries (6.8% vs18.8%, p<0.001). Computer tomography pulmonary angiogram (CTPA) was used only in 35.3% of patients with COVID-19 infection across six studies.

CONCLUSIONS

The in-hospital incidence of acute PE among COVID-19 patients is higher in ICU patients compared to those hospitalized in general wards. CTPA was rarely used suggesting a potential underestimation of PE cases.

Thromboembolism risk of COVID-19 is high and associated with a higher risk of mortality: A systematic review and meta-analysis

BACKGROUND

Studies have suggested that there is increased risk of thromboembolism (TE) associated with coronavirus disease 2019 (COVID-19). However, overall arterial and venous TE rates of COVID-19 and effect of TE on COVID-19 mortality is unknown.

METHODS

We did a systematic review and meta-analysis of studies evaluating TE in COVID-19. We searched PubMed, Cochrane, and Embase for studies published up to June 12, 2020. Random effects models were used to produce summary TE rates and odds ratios (OR) of mortality in COVID-19 patients with TE compared to those without TE. Heterogeneity was quantified with I 2 .

FINDINGS

Of 425 studies identified, 42 studies enrolling 8271 patients were included in the meta-analysis. Overall venous TE rate was 21% (95% CI:17-26%): ICU, 31% (95% CI: 23-39%). Overall deep vein thrombosis rate was 20% (95% CI: 13-28%): ICU, 28% (95% CI: 16-41%); postmortem, 35% (95% CI:15-57%). Overall pulmonary embolism rate was 13% (95% CI: 11-16%): ICU, 19% (95% CI:14-25%); postmortem, 22% (95% CI:16-28%). Overall arterial TE rate was 2% (95% CI: 1-4%): ICU, 5% (95%CI: 3-7%). Pooled mortality rate among patients with TE was 23% (95%CI:14-32%) and 13% (95% CI:6-22%) among patients without TE. The pooled odds of mortality were 74% higher among patients who developed TE compared to those who did not (OR, 1.74; 95%CI, 1.01-2.98; P = 0.04).

INTERPRETATION

TE rates of COVID-19 are high and associated with higher risk of death. Robust evidence from ongoing clinical trials is needed to determine the impact of thromboprophylaxis on TE and mortality risk of COVID-19.

FUNDING

None.

Incidence of thromboembolism in patients with COVID-19: a systematic review and meta-analysis

BACKGROUND

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, the incidence of thromboembolism has been increasingly reported. The aim of this systematic review was to explore the incidence of venous and arterial thromboembolism among COVID-19 patients requiring hospitalization.

METHODS

Medline, Embase, Scopus, and grey literature were searched until June 2020. Observational studies reported on the incidence of venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT) or arterial thromboembolism (ATE) were included. The pool incidences and their 95% confidence intervals (CI) were calculated using the random-effects model.

RESULTS

A total of 36 studies were included. In the intensive care unit (ICU) setting, the pooled incidence of VTE was 28% (95% CI, 22-34%). Subgroups based on compression ultrasound (CUS) screening revealed a higher incidence of DVT in the CUS screening group than in the no CUS screening group (32% [95% CI, 18-45%] vs. 6% [95% CI, 4-9%]). The pooled incidence of ATE in ICU was 3% (95% CI, 2-5%). In the non-ICU setting, the pooled incidence of VTE was 10% (95% CI, 6-14%,).

CONCLUSIONS

The incidence of VTE in COVID-19 patients was higher in the ICU setting than in the non-ICU setting, and also significantly higher in studies that incorporated the CUS screening protocol. The incidence of ATE in the ICU setting was low. VTE prophylactic measures should be given to all hospitalized patients diagnosed with COVID-19.

Can we predict the severe course of COVID-19 - a systematic review and meta-analysis of indicators of clinical outcome?

Background

COVID-19 has been reported in over 40million people globally with variable clinical outcomes. In this systematic review and meta-analysis, we assessed demographic, laboratory and clinical indicators as predictors for severe courses of COVID-19.

Methods

We systematically searched multiple databases (PubMed, Web of Science Core Collection, MedRvix and bioRvix) for publications from December 2019 to May 31st 2020. Random-effects meta-analyses were used to calculate pooled odds ratios and differences of medians between (1) patients admitted to ICU versus non-ICU patients and (2) patients who died versus those who survived. We adapted an existing Cochrane risk-of-bias assessment tool for outcome studies.

Results

Of 6,702 unique citations, we included 88 articles with 69,762 patients. There was concern for bias across all articles included. Age was strongly associated with mortality with a difference of medians (DoM) of 13.15 years (95% confidence interval (CI) 11.37 to 14.94) between those who died and those who survived. We found a clinically relevant difference between non-survivors and survivors for C-reactive protein (CRP; DoM 69.10, CI 50.43 to 87.77), lactate dehydrogenase (LDH; DoM 189.49, CI 155.00 to 223.98), cardiac troponin I (cTnI; DoM 21.88, CI 9.78 to 33.99) and D-Dimer (DoM 1.29mg/L, CI 0.9 - 1.69). Furthermore, cerebrovascular disease was the co-morbidity most strongly associated with mortality (Odds Ratio 3.45, CI 2.42 to 4.91) and ICU admission (Odds Ratio 5.88, CI 2.35 to 14.73).

Discussion

This comprehensive meta-analysis found age, cerebrovascular disease, CRP, LDH and cTnI to be the most important risk-factors in predicting severe COVID-19 outcomes and will inform decision analytical tools to support clinical decision-making.

Coagulopathy, Venous Thromboembolism, and Anticoagulation in Patients with COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has led to a worldwide pandemic, and patients with the infection are referred to as having COVID‐19. Although COVID‐19 is commonly considered a respiratory disease, there is clearly a thrombotic potential that was not expected. The pathophysiology of the disease and subsequent coagulopathy produce an inflammatory, hypercoagulable, and hypofibrinolytic state. Several observational studies have demonstrated surprisingly high rates of venous thromboembolism (VTE) in both general ward and intensive care patients with COVID‐19. Many of these observational studies demonstrate high rates of VTE despite patients being on standard, or even higher intensity, pharmacologic VTE prophylaxis. Fibrinolytic therapy has also been used in patients with acute respiratory distress syndrome. Unfortunately, high quality randomized controlled trials are lacking. A literature search was performed to provide the most up‐to‐date information on the pathophysiology, coagulopathy, risk of VTE, and prevention and treatment of VTE in patients with COVID‐19. These topics are reviewed in detail, along with practical issues of anticoagulant selection and duration. Although many international organizations have produced guidelines or consensus statements, they do not all cover the same issues regarding anticoagulant therapy for patients with COVID‐19, and they do not all agree. These statements and the most recent literature are combined into a list of clinical considerations that clinicians can use for the prevention and treatment of VTE in patients with COVID‐19.

[Proactive anti-inflammatory and anticoagulant therapy in the treatment of advanced stages of novel coronavirus infection (COVID-19). Case Series and Study Design: COLchicine versus ruxolitinib and secukinumab in open prospective randomIzed trial (COLORIT)]

The article is devoted to the treatment of the new coronavirus infection (COVID-19) in the advanced stages of the disease. The types of response of the immune system to the viral load of SARS-CoV-2 with the start of the inflammation process are considered. The situation is analyzed in detail in which the growing autoimmune inflammation (up to the development of a "cytokine storm") affects not only the pulmonary parenchyma, but also the endothelium of the small vessels of the lungs. Simultaneous damage to the alveoli and microthrombosis of the pulmonary vessels are accompanied by a progressive impairment of gas exchange, the development of acute respiratory distress syndrome, the treatment of which, even with the use of invasive ventilation, is ineffective and does not really change the prognosis of patients with COVID-19. In order to interrupt the pathological process at the earliest stages of the disease, the necessity of proactive anti-inflammatory therapy in combination with active anticoagulation treatment is substantiated. The results of the first randomized studies on the use of inhibitors of pro-inflammatory cytokines and chemokines (interleukin-6 (tocilizumab), interleukin-17 (secukinumab), Janus kinase blockers, through which the signal is transmitted to cells (ruxolitinib)), which have potential in the early treatment of COVID- 19. The use of a well-known anti-inflammatory drug colchicine (which is used for gout treatment) in patients with COVID-19 is considered. The design of the original COLORIT comparative study on the use of colchicine, ruxolitinib and secukinumab in the treatment of COVID-19 is presented. Clinical series presented, illustrated early anti-inflammatory therapy together with anticoagulants in patients with COVID-19 and the dangers associated with refusing to initiate such therapy on time.

JAK inhibitors in COVID-19: the need for vigilance regarding increased inherent thrombotic risk

There is accumulating evidence that coronavirus disease 2019 (COVID-19) is a hypercoagulable state. Reports of thrombotic events and autopsy findings of pulmonary thrombotic microangiopathy in patients with COVID-19 are rising [1]. Bompardet al. [2] recently reported a cohort study of 137 patients with COVID-19 pneumonia, in which retrospective review of computed tomography pulmonary angiography scans demonstrated a cumulative incidence of pulmonary emboli (PE) of 24% overall and 50% in intensive care. Although it was initially thought that insidious venous thromboembolic events (VTE) were mainly confined to ventilated patients [3], we now understand thrombotic risk to be a wider problem in COVID-19.

JAK inhibitors have promising therapeutic potential in COVID-19 with dual anti-inflammatory and anti-viral effects. Vigilance to the potentially increased thrombotic risk associated with JAKi is recommended, given the hypercoagulability of COVID-19.https://bit.ly/2NQ15K5

Impact of COVID-19 on the Cardiovascular System: A Review of Available Reports

The recent emergence of the coronavirus disease 19 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in China is now a global health emergency. The transmission of SARS-CoV-2 is mainly via human-to-human contact. This virus is expected to be of zoonotic origin and has a high genome identity to that of bat derived SARS-like coronavirus. Various stringent measures have been implemented to lower person-to-person transmission of COVID-19. Particular observations and attempts have been made to reduce transmission in vulnerable populations, including older adults, children, and healthcare providers. This novel CoV enters the cells through the angiotensin-converting enzyme 2 (ACE2) receptor. There is a higher risk of COVID-19 infection among those with preexisting cardiovascular diseases (CVD), and it has been connected with various direct and indirect complications, including myocarditis, acute myocardial injury, venous thromboembolism, and arrhythmias. This article summarizes the various cardiovascular complications and mechanisms responsible for the same with COVID-19 infection. For the benefit of the scientific community and public, the effect of COVID-19 on major vital organs such as the kidneys, liver, and intestines has been briefly discussed. In this review, we also discuss drugs in different stages of clinical trials and their associated complications, as well as the details of vaccines in various stages of development.

COVID-19 versus HIT hypercoagulability

A striking feature of COVID-19 is the high frequency of thrombosis, particularly in patients who require admission to intensive care unit because of respiratory complications (pneumonia/adult respiratory distress syndrome). The spectrum of thrombotic events is wide, including in situ pulmonary thrombosis, deep-vein thrombosis and associated pulmonary embolism, as well as arterial thrombotic events (stroke, myocardial infarction, limb artery thrombosis). Unusual thrombotic events have also been reported, e.g., cerebral venous sinus thrombosis, mesenteric artery and vein thrombosis. Several hematology abnormalities have been observed in COVID-19 patients, including lymphopenia, neutrophilia, thrombocytopenia (usually mild), thrombocytosis, elevated prothrombin time and partial thromboplastin times (the latter abnormality often indicating lupus anticoagulant phenomenon), hyperfibrinogenemia, elevated von Willebrand factor levels, and elevated fibrin d-dimer. Many of these abnormal hematologic parameters—even as early as the time of initial hospital admission—indicate adverse prognosis, including greater frequency of progression to severe respiratory illness and death. Progression to overt disseminated intravascular coagulation in fatal COVID-19 has been reported in some studies, but not observed in others. We compare and contrast COVID-19 hypercoagulability, and associated increased risk of venous and arterial thrombosis, from the perspective of heparin-induced thrombocytopenia (HIT), including the dilemma of providing thromboprophylaxis and treatment recommendations when available data are limited to observational studies. The frequent use of heparin—both low-molecular-weight and unfractionated—in preventing and treating COVID-19 thrombosis, means that vigilance for HIT occurrence is required in this patient population.

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HIT and COVID-19 are associated with a high risk of thrombosis (venous > arterial).

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HIT and COVID-19 both feature coagulation and “pancellular” activation.

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Therapeutic anticoagulation is indicated for HIT, but dosing unknown for COVID-19.

Thrombosis and COVID-19 pneumonia: the clot thickens!

At the end of last year, a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulted in an acute respiratory illness epidemic in Wuhan, China [1, 2]. The World Health Organization (WHO) termed this illness coronavirus disease 2019 (COVID-19). The coronavirus family have been shown to enter cells through binding angiotensin-converting enzyme 2 (ACE-2), found mainly on alveolar epithelium and endothelium. Activation of endothelial cells is thought to be the primary driver for the increasingly recognised complication of thrombosis.

Pulmonary thrombosis appears to be common in COVID-19 pneumonia and takes two forms, proximal pulmonary emboli and/or distal thrombosis. The possible mechanisms and clinical implications are discussed.https://bit.ly/372Xdhw

An approach to a perceived risk of venous thromboembolism in non-ICU COVID-19 patients in Singapore

Coronavirus disease 2019 (COVID-19) can lead to coagulation activation and venous thromoembolism (VTE), with an incidence of around 25–27%. Patients admitted to the intensive care unit (ICU) are at highest risk. There are not many studies reporting its incidence in non-ICU patients. A large number of COVID-19 patients in Singapore, with symptoms ranging from mild to moderate, have been admitted to either Community Care Facilities (CCF) or in general wards of Public Healthcare Institutions (PHI). In case there is a surge of COVID-19 patients, there is a possibility that general wards in PHIs may need to admit an increasing numbers of acutely ill patients, with only the critical ones being admitted to ICU. The incidence of VTE in non-ICU patients is not exactly known and its detection in these patients is challenging. Thus, the healthcare staff managing these patients at the CCFs and general wards at the PHIs should be vigilant and monitor these patients for development of signs and symptoms of deep vein thrombosis, as well as trend D-dimer level. An algorithm for a potential approach to manage VTE in non-ICU COVID-19 patients is described. A prospective study is needed to establish the incidence of VTE in non-ICU patients in Singapore and the predictive value of D-dimer levels to detect this risk, as well as a therapeutic protocol to initiate appropriate pharmacological thromboprophylaxis in these patients.

Venous thromboembolism in patients with COVID-19 (SARS-CoV-2 infection) - a position paper of the German Society of Angiology (DGA)

As observed in other infections with a systemic inflammatory response, severe COVID-19 is associated with hypercoagulability and a prothrombotic state. Currently, there is growing evidence that pulmonary embolism and thrombosis contribute to adverse outcomes and increased mortality in critically ill patients with COVID-19. The optimal thromboprophylactic regimen for patients with COVID-19 is not known. Whereas pharmacologic thromboprophylaxis is generally recommended for all hospitalized COVID-19 patients, adequate dosing of anticoagulants remains a controversial issue. Therefore, we summarize current evidence from the available literature and, on behalf of the German Society of Angiology (DGA), we aim to provide advice to establish an improved and more uniform strategy for thromboprophylaxis in patients with COVID-19.