Venous thromboembolism in critically Ill patients with COVID-19: Results of a screening study for deep vein thrombosis

The 2023 Belgian clinical guidance on anticoagulation management in hospitalized and ambulatory COVID-19 patients

COVID-19 is associated with an increased risk for thrombotic complications. The trials investigating the optimal thromboprophylactic dose are performed in challenging times and seemingly produce conflicting evidence. The burdensome circumstances, divergent endpoints, and different analytical approaches hamper comparison and extrapolation of available evidence. Most importantly, clinicians should provide thromboprophylaxis in hospitalized COVID-19 patients while (re)assessing bleeding and thrombotic risk frequently. The COVID-19 Thromboprophylaxis Working Group of the BSTH updated its guidance document. It aims to summarize the available evidence critically and to guide clinicians in providing the best possible thromboprophylaxis.

Prevalence of Thromboembolic Events, Including Venous Thromboembolism and Arterial Thrombosis, in Patients with COVID-19: A Systematic Review with Meta-Analysis

Background

Many studies have evaluated thromboembolic events in COVID-19 patients, and most of them have reported a high estimation of the prevalence of such events. The present study sought to evaluate the prevalence of thromboembolic events in patients with COVID-19.

Methods

This study is a systematic review with meta-analysis that investigated thromboembolic events in patients with COVID-19 from the start of the pandemic to August 31, 2021. The 4 main databases for collecting articles were Medline, Scopus, Google Scholar, and Web of Science. Deep vein thrombosis, pulmonary embolism, arterial thrombosis, and the overall rate of thromboembolic events were considered primary outcomes.

Results

In a total of 63 studies (104 920 patients with COVID-19), the overall thrombosis rate was 21% (95% CI, 18% to 25%), the rate of deep vein thrombosis was 20% (95% Cl, 16% to 25%), the rate of pulmonary embolism was 8% (95% Cl, 6% to 10%), and the rate of arterial thrombosis was 5% (95% Cl, 3% to 7%). The prevalence of all primary outcomes in critically ill patients admitted to the intensive care unit (ICU) was significantly higher (P<0.05). In older patients, the prevalence of overall thrombosis, pulmonary embolism, or deep vein thrombosis was significantly higher (P<0.05).

Conclusion

This study showed that COVID-19 increases the risk of thromboembolic events, especially in elderly and critically ill patients admitted to the ICU. Therefore, more strategies are needed to prevent thromboembolic events in patients with COVID-19, especially in ICU-admitted and elderly patients.

Coagulopathy and thromboembolic events a pathogenic mechanism of COVID-19 associated with mortality: An updated review

During 2019, the SARS-CoV-2 emerged from China, and during months, COVID-19 spread in many countries around the world. The expanding data about pathogenesis of this virus could elucidate the exact mechanism by which COVID-19 caused death in humans. One of the pathogenic mechanisms of this disease is coagulation. Coagulation disorders that affect both venous and arterial systems occur in patients with COVID-19. The possible mechanism involved in the coagulation could be excessive inflammation induced by SARS-CoV-2. However, it is not yet clear well how SARS-CoV-2 promotes coagulopathy. However, some factors, such as pulmonary endothelial cell damage and some anticoagulant system disorders, are assumed to have an important role. In this study, we assessed conducted studies about COVID-19-induced coagulopathy to obtain clearer vision of the wide range of manifestations and possible pathogenesis mechanisms.

Venous thromboembolism in viral diseases: A comprehensive literature review

Venous thromboembolism (VTE) is known to be a common respiratory and/or cardiovascular complication in hospitalized patients with viral infections. Numerous studies have proven human immunodeficiency virus infection to be a prothrombotic condition. An elevated VTE risk has been observed in critically ill H1N1 influenza patients. VTE risk is remarkably higher in patients infected with the Hepatitis C virus in contrast to uninfected subjects. The elevation of D-dimer levels supported the association between Chikungunya and the Zika virus and the rise of clinical VTE risk. Varicella-zoster virus is a risk factor for both cellulitis and the consequent invasive bacterial disease which may take part in thrombotic initiation. Eventually, hospitalized patients infected with the coronavirus disease of 2019 (COVID-19), the cause of the ongoing worldwide pandemic, could mainly suffer from an anomalous risk of coagulation activation with enhanced venous thrombosis events and poor quality clinical course. Although the risk of VTE in nonhospitalized COVID-19 patients is not known yet, there are a large number of guidelines and studies on thromboprophylaxis administration for COVID-19 cases. This study aims to take a detailed look at the effect of viral diseases on VTE, the epidemiology of VTE in viral diseases, and the diagnosis and treatment of VTE.

Risk factors and mortality of pulmonary embolism in COVID-19 patients: Evidence based on fifty observational studies

BACKGROUND

At present, many studies have described acute pulmonary embolism (PE) as a frequent and prognostically relevant complication of coronavirus disease 2019 (COVID-19) infection. Thus we performed the present analysis of 50 studies to evaluate the risk factors and mortality of PE in COVID-19 patients.

METHOD

Databases including PubMed, Embase, Cochrane Library and Web of Science were searched to October, 2021. Odds ratio (OR), mean difference (MD) or standard MD was used to evaluate the outcomes. The primary outcomes were the difference of mortality between PE and non-PE COVID-19 patients as well as relevant risk factors of PE in COVID-19 patients. All statistical analyses were performed using the standard statistical procedures provided in Review Manager 5.2.

RESULT

A total of 50 studies including 10053 patients were included in this meta-analysis. Our results indicated that COVID-19 patients with PE experienced significantly higher mortality than non-PE patients (21.9% vs. 10.7%), with a pooled OR of 2.21 (95% CI 1.30 - 3.76; P = .003). In addition, COVID-19 patients with PE also experienced more mechanical ventilation (MV) (OR 2.21; 95% CI 1.30 - 3.75; P = .003) and invasive mechanical ventilation (IMV) (OR 3.58; 95% CI 2.47 - 5.20; P < .0001) respectively. Univariate analysis (UVA) results indicated the Sequential Organ Failure Assessment (SOFA) score, time to deep venous thrombosis (DVT), nonintensive care unit (non-ICU) patients and no anticoagulation as risk factors of PE for COVID-19 patients. In addition, multivariate analysis also found that SOFA score, D-dimer, BMI > 30 kg/m2 and history of PE were risk factors of PE for COVID-19 patients.

CONCLUSION

The present analysis indicated that PE increased the mortality of COVID-19 patients. Mechanical ventilation, especially invasive mechanical ventilation, is correlated with an increased incidence of PE in patients with COVID-19. The incidence of PE for COVID-19 patients may be multifactorial and further researches focused on risk factors were needed in the future.

Pulmonary embolism in patients with COVID-19 and D-dimer diagnostic value: A retrospective study

BACKGROUND

D-dimer levels are significantly higher in COVID-19 patients with Pulmonary Thromboembolism (PTE) as compared to those without PTE, but its clinical utility is still uncertain.

PURPOSE

To determine the D-dimer performance for ruling out PTE in patients with COVID-19. We also assessed clinical and laboratory factors associated with the presence of PTE on CT Pulmonary Angiogram (CTPA).

METHODS

Retrospective study involving all patients who presented at a tertiary care hospital from March 2020 to May 2021 with severe acute respiratory syndrome from COVID-19, who underwent CTPA and had D-dimer collected within 48 hours from CTPA. The D-dimer ability to classify patients with or without PTE according to CTPA was evaluated.

RESULTS

A total of 697 patients [382 (54.8%) men; mean (SD) age, 59 (20.5) years] were included, of which 71.5% required intensive care admission, 32.4% had PTE, and 35.6% died during hospitalization. PTE was independently associated with mortality [42.5% vs. 32.3%; p = 0.038]. D-dimer levels were higher in patients with PTE [9.1 (3.9; 20) vs. 2.3 (1.2; 5.1); p < 0.001]. Using the D-dimer cutoff of 0.5 μg/mL or above, sensitivity was 98.2% and specificity 5.7%. The 0.3 μg/mL threshold was associated with 100% of sensitivity for the presence of PTE, with which 99.1% of patients had increased values. ROC curve AUC was 0.77, demonstrating moderate discriminative power of D-dimers to detect PTE.

CONCLUSIONS

D-dimer levels are higher among COVID-19 hospitalized patients with PTE as compared to those without PTE and have moderate discriminative power to detect PTE, but its use to exclude PTE in this population may have limited clinical utility.

Compressive ultrasound can predict early pulmonary embolism onset in COVID patients

PURPOSE

To evaluate the usefulness of compressive ultrasound (CUS) for the diagnosis of deep vein thrombosis (DVT) in patients with SARS-CoV-2-related infection.

METHODS

112 hospitalized patients with confirmed SARS-CoV-2 infection were retrospectively enrolled. CUS was performed within 2 days of admission and consisted in the assessment of the proximal and distal deep venous systems. Lack of compressibility, or direct identification of an endoluminal thrombus, were the criteria used for the diagnosis of DVT. Pulmonary embolism (PE) events were investigated at computed tomography pulmonary angiography (CTPA) within 5 days of follow-up. Logistic binary regression was computed to determine which clinical and radiological parameters were independently associated with PE onset.

RESULTS

Overall, the incidence of DVT in our cohort was about 43%. The most common district involved was the left lower limb (68.7%) in comparison with the right one (58.3%) while the upper limbs were less frequently involved (4.2% the right one and 2.1% the left one, respectively). On both sides, the distal tract of the popliteal vein was the most common involved (50% right side and 45.8% left side). The presence of DVT in the distal tract of the right popliteal vein (OR = 2.444 95%CIs 1.084-16.624, p = 0.038), in the distal tract of the left popliteal vein (OR = 4.201 95%CIs 1.484-11.885, p = 0.007), and D-dimer values (OR = 2.122 95%CIs 1.030-5.495, p = 0.003) were independently associated with the onset on PE within 5 days.

CONCLUSIONS

CUS should be considered a useful tool to discriminate which category of patients can develop PE within 5 days from admission.

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.

A systematic review of biomarkers among hospitalized patients with COVID-19 predictive of venous thromboembolism: A communication from the Predictive and Diagnostic Variables Scientific and Standardization Committee of the ISTH

Background

Thrombosis is reported to occur more often among patients with COVID-19 than otherwise expected in the setting of viral pneumonia and sepsis. Systemic inflammatory biomarkers may be associated with venous thromboembolism (VTE) risk. The ISTH subcommittee on Predictive and Diagnostic Variables in Thrombotic Disease aimed to report the evidence on prognostic biomarkers for VTE in hospitalized patients with COVID-19.

Methods

Using a standardized Preferred Reporting Items for Systematic Reviews and Meta-analysis methodology, we conducted a systematic literature review to identify studies reporting prognostic biomarkers for VTE among hospitalized patients with COVID-19. Eligible studies included adults hospitalized with COVID-19 and reported the prognostic associations between any biomarker measured on admission, and the subsequent diagnosis of deep vein thrombosis or pulmonary embolism. Two authors reviewed titles and abstracts, and three authors extracted study data and performed review of bias. Results were displayed descriptively. Meta-analysis was not possible.

Results

From the initial 196 identified studies, full-text review was performed for 72 studies. Admission D-dimer levels were associated with VTE during hospitalization in five studies, and elevated platelet count was associated with VTE during hospitalization in one study. The risk of bias ranged from low to high for included studies. Overall, there was a paucity of high-quality prognostic studies. Studies on other biomarkers did not meet the systematic review inclusion criteria.

Conclusions

Admission D-dimer was associated with VTE diagnosis during hospitalization for COVID-19; however, prospective validation of this finding is needed to identify optimal D-dimer thresholds to guide VTE prophylaxis measures.

Venous and arterial thrombosis in COVID-19: An updated narrative review

Hospitalized patients with coronavirus disease 2019 (COVID-19), particularly those admitted to the intensive care unit (ICU) are at high risk of morbidity and mortality. Several observational studies have described hemostatic derangements and thrombotic complications in patients with COVID-19. The aim of this review article is to summarize the current evidence on pathologic findings, pathophysiology, coagulation and hemostatic abnormalities, D-dimer's role in prognostication epidemiology and risk factors of thrombotic complications, and the role of prophylactic and therapeutic anticoagulation in patients with COVID-19. While existing evidence is limited in quality, COVID-19 appears to increase micro-and macro-vascular thrombosis rates in hospitalized and critically ill patients, which may contribute to the burden of disease. D-dimer can be used for risk stratification of hospitalized patients, but its role to guide anticoagulation therapy remains unclear. Evidence of higher quality is needed to address the role of therapeutic anticoagulation or high-intensity venous thromboembolism prophylaxis in COVID-19 patients. TAKE-HOME POINTS.

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.

Therapeutic anticoagulation to prevent thrombosis, coagulopathy, and mortality in severe COVID‐19: The Swiss COVID‐HEP randomized clinical trial

Background

Hospitalized patients with COVID‐19 suffered initially from high rates of venous thromboembolism (VTE), with possible associations between therapeutic anticoagulation and better clinical outcomes in observational studies.

Objective

To test whether therapeutic anticoagulation improves clinical outcomes in severe COVID‐19.

Patients/Methods

In this multicenter, open‐label, randomized controlled trial, we recruited acutely ill medical COVID‐19 patients with D‐dimer >1000 ng/ml or critically ill COVID‐19 patients in four Swiss hospitals, from April 2020 until June 2021, with a 30‐day follow‐up. Participants were randomized to in‐hospital therapeutic anticoagulation versus low‐dose anticoagulation in acutely ill participants/intermediate‐dose anticoagulation in critically ill participants, with enoxaparin or unfractionated heparins. The primary outcome was a centrally adjudicated composite of 30‐day all‐cause mortality, VTE, arterial thrombosis, and disseminated intravascular coagulopathy (DIC), with screening for proximal deep vein thrombosis.

Results

Among 159 participants, 55.3% were critically ill and 94.3% received corticosteroids. Before study inclusion, pulmonary embolism had been excluded in 71.7%. The primary outcome occurred in 4/79 participants randomized to therapeutic anticoagulation and 4/80 to low/intermediate anticoagulation (5.4% vs. 5.0%; risk difference +0.4%; adjusted hazard ratio 0.76, 95% confidence interval 0.18–3.21), including three deaths in each group. All primary outcomes and major bleeding (n = 3) occurred in critically ill participants. There was no asymptomatic proximal deep vein thrombosis and no difference in major bleeding.

Conclusions

Among patients with severe COVID‐19 treated with corticosteroids and with exclusion of pulmonary embolism at hospital admission for most, risks of mortality, thrombotic outcomes, and DIC were low at 30 days. The lack of benefit of therapeutic anticoagulation was too imprecise for definite conclusions.

Incidence and prognostic value of pulmonary embolism in COVID-19: A systematic review and meta-analysis

Background

Pulmonary embolisms are frequently and prognostically in individuals infected by coronavirus disease 2019 (COVID-19); the incidence of pulmonary embolisms is varied across numerous studies. This study aimed to assess the pooled incidence of pulmonary embolic events and the prognostic value of such events in intensive care unit (ICU) admissions of patients with COVID-19.

Methods

The Cochrane Library, PubMed, and EmBase were systematically searched for eligible studies published on or before October 20, 2021. The pooled incidence of pulmonary embolism was calculated using the random-effects model. Moreover, the prognostic value was assessed by measuring the sensitivity, specificity, positive and negative likelihood ratio (PLR and NLR), diagnostic odds ratio (DOR), and the area under the receiver operating characteristic curve (AUC).

Results

Thirty-six studies involving 10,367 COVID-19 patients were selected for the final meta-analysis. The cumulative incidence of pulmonary embolism in patients with COVID-19 was 21% (95% confidence interval [95%CI]: 18−24%; P<0.001), and the incidence of pulmonary embolism in ICU and non-ICU patients was 26% (95%CI: 22−31%; P<0.001) and 17% (95%CI: 14−20%; P<0.001), respectively. The predictive role of pulmonary embolism in ICU admission was also assessed, and the sensitivity, specificity, PLR, NLR, DOR, and AUC were 0.31 (95%CI: 0.21−0.42), 0.84 (95%CI: 0.75−0.90), 1.88 (95%CI: 1.45−2.45), 0.83 (95%CI: 0.75−0.91), 2.25 (95%CI: 1.64−3.08), and 0.61 (95%CI: 0.57−0.65), respectively.

Conclusion

This study found that the incidence of pulmonary embolism was relatively high in COVID-19 patients, and the incidence of pulmonary embolism in ICU patients was higher than that in non-ICU patients.

Thromboprophylaxis in COVID-19: Weight and severity adjusted intensified dosing

Background

Venous thromboembolism (VTE) frequently occurs in hospitalized patients with coronavirus disease 2019 (COVID-19). The optimal dose of anticoagulation for thromboprophylaxis in COVID-19 is unknown.

Aims

To report VTE incidence and bleeding before and after implementing a hospital-wide intensified thromboprophylactic protocol in patients with COVID-19.

Methods

On March 31, 2020, we implemented an intensified thromboprophylactic protocol consisting of 50 IU anti-Xa low molecular weight heparin (LMWH)/kg once daily at the ward, twice daily at the intensive care unit (ICU). We included all patients hospitalized in a tertiary care hospital with symptomatic COVID-19 between March 7 and July 1, 2020. The primary outcome was the incidence of symptomatic or subclinical VTE and major bleeding during admission. Routine ultrasound screening for VTE was performed whenever logistically possible.

Results

We included 412 patients, of which 116 were admitted to the ICU. Of 219 patients with standard a prophylactic dose of LMWH, 16 (7.3%) had VTE, 10 of which were symptomatic (4.6%). Of 193 patients with intensified thromboprophylaxis, there were no symptomatic VTE cases, three incidental deep venous thrombosis cases (1.6%), and one incidental pulmonary embolism (0.5%). The major bleeding rate was 1.2% in patients with intensified thromboprophylaxis and 7.7% when therapeutic anticoagulation was needed.

Conclusion

In hospitalized patients with COVID-19, there were no additional symptomatic VTEs and a reduction in incidental deep vein thrombosis after implementing systematic thromboprophylaxis with weight-adjusted prophylactic (ward) to intermediate (ICU), but not therapeutic dosed anticoagulation. This intensified thromboprophylaxis was associated with a lower risk of major bleeding compared with therapeutic dosed anticoagulation.

Clotting events among hospitalized patients infected with COVID-19 in a large multisite cohort in the United States

INTRODUCTION

COVID-19 infection has been hypothesized to precipitate venous and arterial clotting events more frequently than other illnesses.

MATERIALS AND METHODS

We demonstrate this increased risk of blood clots by comparing rates of venous and arterial clotting events in 4400 hospitalized COVID-19 patients in a large multisite clinical network in the United States examined from April through June of 2020, to patients hospitalized for non-COVID illness and influenza during the same time period and in 2019.

RESULTS

We demonstrate that COVID-19 increases the risk of venous thrombosis by two-fold compared to the general inpatient population and compared to people with influenza infection. Arterial and venous thrombosis were both common occurrences among patients with COVID-19 infection. Risk factors for thrombosis included male gender, older age, and diabetes. Patients with venous or arterial thrombosis had high rates of admission to the ICU, re-admission to the hospital, and death.

CONCLUSION

Given the ongoing scientific discussion about the impact of clotting on COVID-19 disease progression, these results highlight the need to further elucidate the role of anticoagulation in COVID-19 patients, particularly outside the intensive care unit setting. Additionally, concerns regarding clotting and COVID-19 vaccines highlight the importance of addressing the alarmingly high rate of clotting events during actual COVID-19 infection when weighing the risks and benefits of vaccination.

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.

Heparin-induced thrombocytopenia in patients with COVID-19: a systematic review and meta-analysis

Heparin thromboprophylaxis is routinely administered during hospitalization for COVID-19. Because of the immune stimulation related to COVID-19, there is ongoing concern regarding a heightened incidence of heparin-induced thrombocytopenia (HIT). We performed a literature search using PubMed, EMBASE, Cochrane, and medRxiv database to identify studies that reported clinical and laboratory characteristics and/or the incidence of HIT in patients with COVID-19. The primary aim was to systematically review the clinical features and outcomes of patients with COVID-19 with confirmed HIT. The secondary objective was to perform a meta-analysis to estimate the incidence of HIT in hospitalized patients with COVID-19. A meta-analysis of 7 studies including 5849 patients revealed the pooled incidence of HIT in COVID-19 of 0.8% (95% confidence interval [CI], 0.2%-3.2%; I² = 89%). The estimated incidences were 1.2% (95% CI, 0.3%-3.9%; I² = 65%) vs 0.1% (95% CI, 0.0%-0.4%; I² = 0%) in therapeutic vs prophylactic heparin subgroups, respectively. The pooled incidences of HIT were higher in critically ill patients with COVID-19 (2.2%; 95% CI, 0.6%-8.3%; I² = 72.5%) compared with noncritically ill patients (0.1%; 95% CI, 0.0%-0.4%: I² = 0%). There were 19 cases of confirmed HIT and 1 with autoimmune HIT for clinical and laboratory characterization. The median time from heparin initiation to HIT diagnosis was 13.5 days (interquartile range, 10.75-16.25 days). Twelve (63%) developed thromboembolism after heparin therapy. In conclusion, the incidence of HIT in patients with COVID-19 was comparable to patients without COVID-19, with higher incidences with therapeutic anticoagulation and in critically ill patients.

Incidence of thrombotic complications in COVID-19 : On behalf of ICODE: The International COVID-19 Thrombosis Biomarkers Colloquium

A high incidence of thrombosis in hospitalised patients with COVID-19 was identified early during the pandemic. Accurately quantifying thrombotic risk may assist prognosis and guide appropriate thromboprophylaxis. Observational studies have estimated the rate of thrombosis in both hospitalised and non-hospitalised patients with COVID-19, and how this corresponds to the severity of illness. In this review, we provide an overview of the incidence and prevalence of arterial and venous thrombotic events in patients with COVID-19 and highlight the limitations in the studies to date. Asymptomatic individuals with COVID-19 and those with mild symptoms are at very low risk of thrombotic complications. However, rates of thrombosis are substantially increased in hospitalised patients, and are strikingly high in those patients who are critically-ill requiring treatment on the intensive care unit and especially those requiring extracorporeal membrane oxygenation. Clinicians managing such patients need to be aware of these risks and take appropriate steps with respect to thromboprophylaxis and heightened clinical vigilance. Large prospective observational studies will more accurately quantify thrombotic rate, and randomized controlled trials are currently investigating optimal thromboprophylactic strategies.

Prevalence and risk factors for venous thromboembolic events in critically ill patients with SARS-CoV-2 infection: a prospective observational study

BACKGROUND

The majority of prevalence studies on deep vein thrombosis (DVT) in severe COVID-19 patients are retrospective with DVT assessment based on clinical suspicion. Our aim was to prospectively and systematically estimate the occurrence of DVT in critically-ill mechanically-ventilated patients, and to identify potential risk factors for DVT occurrence and mortality.

METHODS

All patients with COVID-19 admitted to our 45 beds in the Intensive Care Unit (ICU) between March 6, 2020, and April 18, 2020, requiring invasive ventilatory support were daily screened for DVT with lower extremities and jugular veins ultrasonography. Univariate and multivariable logistic regression models were performed in order to identify predictors of DVT and mortality.

RESULTS

Seventy-six patients were included in the final analysis (56 men, mean age 67 years, median SOFA=7 points, median SAPS II=41 points, median PaO<inf>2</inf>/Fi0<inf>2</inf>=10.8 kPa). The period prevalence of DVT was 40.8%. Thirty-one DVTs were diagnosed. Twenty-five DVTs (80.6% of total DVTs) were catheter-related, mainly in the jugular veins. Twenty-six DVTs (83.9%) occurred in patients receiving enhanced antithrombotic prophylaxis. No independent variable was predictive of DVT occurrence. Twenty-eight patients (36.8%) died during the ICU stay. Age and SOFA score were independently associated with mortality.

CONCLUSIONS

A high number of critically-ill mechanically-ventilated COVID-19 patients developed a DVT. The majority of DVTs were catheter-related and occurred under intensive prophylactic anticoagulation. Routine ultrasound of the jugular veins should be suggested in this patient population, and in particular in presence of a central venous catheter.

Arterial and venous thromboembolism in COVID-19: a study-level meta-analysis

BACKGROUND

The prevalence of venous thromboembolic event (VTE) and arterial thromboembolic event (ATE) thromboembolic events in patients with COVID-19 remains largely unknown.

METHODS

In this meta-analysis, we systematically searched for observational studies describing the prevalence of VTE and ATE in COVID-19 up to 30 September 2020.

RESULTS

We analysed findings from 102 studies (64 503 patients). The frequency of COVID-19-related VTE was 14.7% (95% CI 12.1% to 17.6%, I2=94%; 56 studies; 16 507 patients). The overall prevalence rates of pulmonary embolism (PE) and leg deep vein thrombosis were 7.8% (95% CI 6.2% to 9.4%, I2=94%; 66 studies; 23 117 patients) and 11.2% (95% CI 8.4% to 14.3%, I2=95%; 48 studies; 13 824 patients), respectively. Few were isolated subsegmental PE. The VTE prevalence was significantly higher in intensive care unit (ICU) (23.2%, 95% CI 17.5% to 29.6%, I2=92%, vs 9.0%, 95% CI 6.9% to 11.4%, I2=95%; pinteraction<0.0001) and in series systematically screening patients compared with series testing symptomatic patients (25.2% vs 12.7%, pinteraction=0.04). The frequency rates of overall ATE, acute coronary syndrome, stroke and other ATE were 3.9% (95% CI 2.0% to to 3.0%, I2=96%; 16 studies; 7939 patients), 1.6% (95% CI 1.0% to 2.2%, I2=93%; 27 studies; 40 597 patients) and 0.9% (95% CI 0.5% to 1.5%, I2=84%; 17 studies; 20 139 patients), respectively. Metaregression and subgroup analyses failed to explain heterogeneity of overall ATE. High heterogeneity limited the value of estimates.

CONCLUSIONS

Patients admitted in the ICU for severe COVID-19 had a high risk of VTE. Conversely, further studies are needed to determine the specific effects of COVID-19 on the risk of ATE or VTE in less severe forms of the disease.

COVID and venous thrombosis: systematic review of literature

INTRODUCTION

We aimed to review the prevalence, the risk factors and the outcomes of venous thrombosis (VT) in patients hospitalized for COronaVirus Disease 19 (COVID-19).

METHODS

Electronic bibliographic databases were searched using the words "COVID venous thrombosis". The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards.

RESULTS

The search of the Literature retrieved 877 results. After assessment of full texts, 69 papers were included in the qualitative analysis and 23 of them in the quantitative evaluation. The analyzed studies included a total of 106838 patients hospitalized for COVID-19 from 01/2020 to 12/2020. The pooled reported prevalence rate of VT was in median 16.7% (IQR 5.8%-30%), being higher in ICU patients (60.8%-85.4%). VT events were reported in about 75% of cases in the popliteal and calf veins. Signs and symptoms were present in 6.1% of cases. At quantitative evaluation, older age, D-dimer and obesity increased the odds to experience a VT (OR 3.54, 95%CI 0.65-6.43, P=0.01; OR=956.86, 95%CI 225.67-1668.05, P=0.01; OR 1.42, 95%CI 1.01-1.99, P=0.03 respectively). Female sex seemed to be protective against the odds of VT (OR 0.77, 95%CI 0.63-0.93, P=0.007).

CONCLUSIONS

Among patients hospitalized for COVID-19, VT is a relatively common finding, with higher prevalence rates in ICU patients. VT occurs mostly in the distal regions of the lower limb and is asymptomatic in most cases. Older age, obesity and higher D-dimer values on admission increased the odds of VT, while female sex was protective against the odds of VT.

A systematic review and meta-analysis of incidence, prognosis, and laboratory indicators of venous thromboembolism in hospitalized patients with coronavirus disease 2019

OBJECTIVE

We have summarized the incidence, anticoagulation panels, laboratory characteristics, and mortality of venous thromboembolism (VTE) in hospitalized patients with coronavirus disease 2019 (COVID-19).

METHODS

After systematically searching PubMed, Embase, the Cochrane Library, MedRxiv, and BioRxiv, a systematic review and meta-analysis of 18 retrospective, 6 prospective observational, and 2 cross-sectional studies was performed according to the guidelines of the PRISMA (preferred reporting items for systematic reviews and meta-analyses) statement.

RESULTS

Overall, 4382 hospitalized patients with COVID-19 were included. Men accounted for significantly more patients than did women (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.25-2.02; P < .001). The total incidence of VTE among the patients with COVID-19 was 28.3% (95% CI, 21.6%-35.4%), with an incidence of 38.0% (95% CI, 29.1%-47.4%) and 17.2% (95% CI, 11.4%-23.8%) among those with severe and general COVID-19, respectively. The total incidence of deep vein thrombosis (DVT) of the lower extremities was 18.3% (95% CI, 10.8%-27.2%). The incidence of DVT was 22.1% (95% CI, 11.0%-35.5%) and 12.8% (95% CI, 5.0%-23.3%) in those with severe and general COVID-19, respectively. The total incidence of pulmonary embolism was 17.6% (95% CI, 12.3%-23.5%), with a rate of 21.7% (95% CI, 14.8%-29.3%) in severe cases and 12.5% (95% CI, 6.1%-23.5%) in general cases. When COVID-19 severity was unclassified, the mortality for the patients with VTE was not significantly greater (25.2%; 95% CI, 12.2%-40.5%) than that for those without VTE (10.2%; 95% CI, 3.4%-19.5%; OR, 1.88; 95% CI, 0.46-7.64; P = .377). However, among the patients with severe COVID-19, those who had developed VTE had significantly greater mortality compared with those without VTE (OR, 2.02; 95% CI, 1.15-3.53; P = .014). The patients with COVID-19 and VTE had significantly higher D-dimer levels than did similar patients without VTE in multiple studies.

CONCLUSIONS

The occurrence of VTE, DVT, and pulmonary embolism has been substantial among hospitalized patients with COVID-19, especially among those with severe COVID-19. Patients with severe COVID-19 and VTE had significantly greater mortality compared with similar patients without VTE. An increased D-dimer level might be an indicator of the occurrence of VTE in patients with COVID-19.

Cerebral venous sinus thrombosis 2 weeks after the first dose of mRNA SARS-CoV-2 vaccine

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as coronavirus disease 2019 (COVID-19) is a highly transmissible virus and has become pandemic. Part of the prevention of disease spread by the Malaysian government is by getting COVID-19 vaccine. Using the mRNA technology, the Pfizer/BioNTech vaccine is one of the vaccines been approved by the Drug Control Authority in Malaysia. Herein, we report an immediate complication of cerebral VST after the first dose of the Pfizer/BioNTech vaccine.

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.

Cardiovascular injuries and SARS-COV-2 infection: focus on elderly people

The novel coronavirus disease (COVID-19) has hit the healthcare system worldwide. The risk of severe infection and mortality increases with advancing age, especially in subjects with comorbidities such as cardiovascular disease, hypertension, diabetes, obesity and cancer. Moreover, cardiovascular complications such as myocardial injury, heart failure and thromboembolism are frequently observed in COVID-19 cases, and several biomarkers (troponin, NTproBNP and D-Dimer) have been identified as prognostic indicators of disease severity and worst outcome. Currently, there is no specific therapy against SARS-CoV-2, although many medications are under investigation. The aim of this review will be to explore the intertwined relationship between COVID-19 disease and the cardiovascular system, focusing on elderly population. The available supportive treatments along with the related concerns in elderly patients, due to their comorbidities and polypharmacotherapy, will be explored.

A review of thromboembolic events in hospitalized COVID-19 patients

CONTEXT

A higher incidence of thromboembolic disorders in COVID-19 has been reported by many clinicians worldwide.

OBJECTIVE, DESIGN AND DATA SOURCES

Selected studies found in PubMed that reported thromboembolic events were included for meta-analysis using weighted fixed and random effects. Data from 19 articles on cohort studies in patients diagnosed with COVID-19 and thromboembolic events, including thrombosis and embolism were included in this review.

RESULTS

The likelihood for developing thromboembolic disorders in hospitalized COVID-19 patients was 0.28 (95% CI 0.21-0.36).

CONCLUSION

This study further validates the increased risk of VTE in COVID-19 patients when compared to healthy, non-hospitalized people, and hospitalized patients. These findings will be useful to researchers and medical practitioners caring for COVID-19 patients.

Challenges in the diagnostic approach of suspected pulmonary embolism in COVID-19 patients

Accumulating studies on COVID-19 patients report high incidences of thrombotic complications, but guidance on the best diagnostic approach for suspected pulmonary embolism (PE) in COVID-19 patients is lacking. Diagnosing PE in these patients is challenging as signs and symptoms of PE and COVID-19 show wide overlap, D-dimer levels are often elevated in the absence of thrombosis and computed tomography pulmonary angiography (CTPA) may be unfeasible in the case of severe renal impairment and/or hemodynamic instability.This narrative review discusses available literature and guidelines on current diagnostic algorithms for suspected PE in special patient populations, in particular COVID-19. A special focus is on reviewing the literature aimed at identifying symptoms with a high suspicion for PE and on the diagnostic performance of diagnostic algorithms for suspected PE in the setting of COVID-19.Based on available literature, the index of suspicion for PE should be high in the case of unexplained abrupt worsening of respiratory status, typical symptoms of deep-vein thrombosis and/or acute unexplained right ventricular dysfunction. Despite the lack of prospective diagnostic management studies, we propose to adhere to current diagnostic algorithms applying assessment of pretest probability and D-dimer testing as available evidence suggests that these might be considered safe. Preferably, algorithms using adjusted D-dimer thresholds are recommended as it likely improves the yield of the clinical decision rule/D-dimer combination.

Point of care ultrasound screening for deep vein thrombosis in critically ill COVID-19 patients, an observational study

BACKGROUND

Deep vein thrombosis (DVT) is common in critically ill patients with Coronavirus disease 2019 (COVID-19) and may cause fatal pulmonary embolism (PE) prior to diagnosis due to subtle clinical symptoms. The aim of this study was to explore the feasibility of bedside screening for DVT in critically ill COVID-19 patients performed by physicians with limited experience of venous ultrasound. We further aimed to compare inflammation, coagulation and organ dysfunction in patients with and without venous thromboembolism (VTE).

METHODS

This observational study included patients with COVID-19 admitted to the intensive care unit (ICU) of a tertiary hospital in Sweden and screened for DVT with proximal compression ultrasound of the lower extremities between April and July 2020. Screening was performed by ICU residents having received a short online education and one hands-on-session. Pathological screening ultrasound was confirmed by formal ultrasound whereas patients with negative screening underwent formal ultrasound on clinical suspicion. Clinical data, laboratory findings and follow-up were extracted from medical records.

RESULTS

Of 90 eligible patients, 56 were screened by seven ICU residents with no (n = 5) or limited (n = 2) previous experience of DVT ultrasound who performed a median of 4 (IQR 2-19) examinations. Four (7.1%) patients had pathological screening ultrasound of which three (5.6%) were confirmed by formal ultrasound. None of the 52 patients with negative screening ultrasound were diagnosed with DVT during follow-up. Six patients were diagnosed with PE of which four prior to negative screening and two following negative and positive screening respectively. Patients with VTE (n = 8) had higher median peak D-dimer (24.0 (IQR 14.2-50.5) vs. 2.8 (IQR 1.7-7.2) mg/L, p = 0.004), mean peak C-reactive protein (363 (SD 80) vs. 285 (SD 108) mg/L, p = 0.033) and median peak plasma creatinine (288 (IQR 131-328) vs. 94 (IQR 78-131) μmol/L, p = 0.009) compared to patients without VTE (n = 48). Five patients (63%) with VTE received continuous renal replacement therapy compared to six patients (13%) without VTE (p = 0.005).

CONCLUSION

ICU residents with no or limited experience could detect DVT with ultrasound in critically ill COVID-19 patients following a short education. VTE was associated with kidney dysfunction and features of hyperinflammation and hypercoagulation.

TRIAL REGISTRATION

ClinicalTrials ID: NCT04316884 . Registered 20 March 2020.

Prevalence and clinical significance of antiphospholipid antibodies in patients with coronavirus disease 2019 admitted to intensive care units: a prospective observational study

Coronavirus disease 2019 (COVID-19) increases the risk of coagulopathy. Although the presence of antiphospholipid antibodies (aPLs) has been proposed as a possible mechanism of COVID-19-induced coagulopathy, its clinical significance remains uncertain. Therefore, this study aimed to evaluate the prevalence and clinical significance of aPLs among critically ill patients with COVID-19. This prospective observational study included 60 patients with COVID-19 admitted to intensive care units (ICU). The study outcomes included prevalence of aPLs, and a primary composite outcome of all-cause mortality and arterial or venous thrombosis between antiphospholipid-positive and antiphospholipid-negative patients during their ICU stay. Multiple logistic regression was used to assess the influence of aPLs on the primary composite outcome of mortality and thrombosis. A total of 60 critically ill patients were enrolled. Among them, 57 (95%) were men, with a mean age of 52.8 ± 12.2 years, and the majority were from Asia (68%). Twenty-two patients (37%) were found be antiphospholipid-positive; 21 of them were positive for lupus anticoagulant, whereas one patient was positive for anti-β2-glycoprotein IgG/IgM. The composite outcome of mortality and thrombosis during their ICU stay did not differ between antiphospholipid-positive and antiphospholipid-negative patients (4 [18%] vs. 6 [16%], adjusted odds ratio 0.98, 95% confidence interval 0.1–6.7; p value = 0.986). The presence of aPLs does not seem to affect the outcomes of critically ill patients with COVID-19 in terms of all-cause mortality and thrombosis. Therefore, clinicians may not screen critically ill patients with COVID-19 for aPLs unless deemed clinically appropriate.

Screening for Deep Vein Thrombosis in Persons With COVID-19 Upon Admission to an Inpatient Rehabilitation Hospital

OBJECTIVE

The aim of the study was to determine the prevalence of deep venous thrombosis detected by duplex screening and risk factors associated with deep venous thrombosis in patients with COVID-19 upon admission to an inpatient rehabilitation hospital.

DESIGN

This is a retrospective review.

SETTING

The setting is three freestanding inpatient rehabilitation hospitals operating as one system.

PARTICIPANTS

The participants are consecutive patients with a diagnosis of COVID-19 admitted to an inpatient rehabilitation hospital without a diagnosis of deep venous thrombosis or screening duplex ultrasound prior to transfer.

INTERVENTIONS

A duplex ultrasound of lower limbs was performed upon admission to inpatient rehabilitation hospital.

OUTCOME MEASURES

Primary outcome was the percentage of admission patients with a lower limb deep venous thrombosis. Secondary factors included potential risk factors for a positive screen for deep venous thrombosis.

RESULTS

A lower limb deep venous thrombosis was diagnosed in 22% (25/113) of the patients tested, with eight patients (7.1%) having a proximal deep venous thrombosis. Risk factors for screening positive for a deep venous thrombosis included being male, younger, and having been on a ventilator during the acute illness.

CONCLUSIONS

The high rate of deep venous thrombosis observed in these patients suggests that the risk of venous thromboembolic disorders after severe COVID-19 illness is considerable and surveillance measures of such patients should be undertaken.

Venous Thromboembolism in Patients Discharged after COVID-19 Hospitalization

BACKGROUND

 Venous thromboembolism (VTE) is a frequent complication of COVID-19, so that the importance of adequate in-hospital thromboprophylaxis in patients hospitalized with COVID-19 is well established. However, the incidence of VTE after discharge and whether postdischarge thromboprophylaxis is beneficial and safe are unclear. In this prospective observational single-center study, we report the incidence of VTE 6 weeks after hospitalization and the use of postdischarge thromboprophylaxis.

METHODS

 Patients hospitalized with confirmed COVID-19 were invited to a multidisciplinary follow-up clinic 6 weeks after discharge. D-dimer and C-reactive protein were measured, and all patients were screened for deep vein thrombosis with venous duplex-ultrasound. Additionally, selected high-risk patients received computed tomography pulmonary angiogram or ventilation-perfusion (V/Q) scan to screen for incidental pulmonary embolism.

RESULTS

 Of 485 consecutive patients hospitalized from March through June 2020, 146 patients were analyzed, of which 39% had been admitted to the intensive care unit (ICU). Postdischarge thromboprophylaxis was prescribed in 28% of patients, but was used more frequently after ICU stay (61%) and in patients with higher maximal D-dimer and C-reactive protein levels during hospitalization. Six weeks after discharge, elevated D-dimer values were present in 32% of ward and 42% of ICU patients. Only one asymptomatic deep vein thrombosis (0.7%) and one symptomatic pulmonary embolism (0.7%) were diagnosed with systematic screening. No bleedings were reported.

CONCLUSION

 In patients who had been hospitalized with COVID-19, systematic screening for VTE 6 weeks after discharge revealed a low incidence of VTE. A strategy of selectively providing postdischarge thromboprophylaxis in high-risk patients seems safe and potentially effective.

Deep vein thrombosis and pulmonary embolism among hospitalized coronavirus disease 2019-positive patients predicted for higher mortality and prolonged intensive care unit and hospital stays in a multisite healthcare system

Objective

We assessed the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) in hospitalized patients with coronavirus disease 2019 (COVID-19) compared with that in a matched cohort with similar cardiovascular risk factors and the effects of DVT and PE on the hospital course.

Methods

We performed a retrospective review of prospectively collected data from COVID-19 patients who had been hospitalized from March 11, 2020 to September 4, 2020. The patients were randomly matched in a 1:1 ratio by age, sex, hospital of admission, smoking history, diabetes mellitus, and coronary artery disease with a cohort of patients without COVID-19. The primary end point was the incidence of DVT/PE and the odds of developing DVT/PE using a conditional logistic regression model. The secondary end point was the hospitalization outcomes for COVID-19 patients with and without DVT/PE, including mortality, intensive care unit (ICU) admission, ICU stay, and length of hospitalization (LOH). Multivariable regression analysis was performed to identify the variables associated with mortality, ICU admission, discharge disposition, ICU duration, and LOH.

Results

A total of 13,310 patients had tested positive for COVID-19, 915 of whom (6.9%) had been hospitalized across our multisite health care system. The mean age of the hospitalized patients was 60.8 ± 17.0 years, and 396 (43.3%) were women. Of the 915 patients, 82 (9.0%) had had a diagnosis of DVT/PE confirmed by ultrasound examination of the extremities and/or computed tomography angiography of the chest. The odds of presenting with DVT/PE in the setting of COVID-19 infection was greater than that without COVID-19 infection (0.6% [5 of 915] vs 9.0% [82 of 915]; odds ratio [OR], 18; 95% confidence interval [CI], 8.0-51.2; P < .001). The vascular risk factors were not different between the COVID-19 patients with and without DVT/PE. Mortality (P = .02), the need for ICU stay (P < .001), duration of ICU stay (P < .001), and LOH (P < .001) were greater in the DVT/PE cohort than in the cohort without DVT/PE. On multivariable logistic regression analysis, the hemoglobin (OR, 0.71; 95% CI, 0.46-0.95; P = .04) and D-dimer (OR, 1.0; 95% CI, 0.33-1.56; P = .03) levels were associated with higher mortality. Higher activated partial thromboplastin times (OR, 1.1; 95% CI, 1.00-1.12; P = .03) and higher interleukin-6 (IL-6) levels (OR, 1.0; 95% CI, 1.01-1.07; P = .05) were associated with a greater risk of ICU admission. IL-6 (OR, 1.0; 95% CI, 1.00-1.02; P = .05) was associated with a greater risk of rehabilitation placement after discharge. On multivariable gamma regression analysis, hemoglobin (coefficient, −3.0; 95% CI, 0.03-0.08; P = .005) was associated with a prolonged ICU stay, and the activated partial thromboplastin time (coefficient, 2.0; 95% CI, 0.003-0.006; P = .05), international normalized ratio (coefficient, −3.2; 95% CI, 0.06-0.19; P = .002) and IL-6 (coefficient, 2.4; 95% CI, 0.0011-0.0027; P = .02) were associated with a prolonged LOH.

Conclusions

A significantly greater incidence of DVT/PE occurred in hospitalized COVID-19–positive patients compared with a non–COVID-19 cohort matched for cardiovascular risk factors. Patients affected by DVT/PE were more likely to experience greater mortality, to require ICU admission, and experience prolonged ICU stays and LOH compared with COVID-19–positive patients without DVT/PE. Advancements in DVT/PE prevention are needed for patients hospitalized for COVID-19 infection.

A Review of Thromboembolic Events in Hospitalized COVID-19 Patients

Context: A higher incidence of thromboembolic disorders in COVID-19 has been reported by many clinicians worldwide. Objective, Design and Data Sources: Selected studies found in PubMed that reported thromboembolic events were included for meta-analysis using weighted fixed and random effects. Data from 19 articles on cohort studies in patients diagnosed with COVID-19 and thromboembolic events, including thrombosis and embolism were included in this review. Results: The likelihood for developing thromboembolic disorders in hospitalized COVID-19 patients was 0.28 (95% CI 0.21â€"0.36). Conclusion: This study further validates the increased risk of VTE in COVID-19 patients when compared to healthy, non-hospitalized people, and hospitalized patients. These findings will be useful to researchers and medical practitioners caring for COVID-19 patients.

Mortality in patients admitted to intensive care with COVID-19: an updated systematic review and meta-analysis of observational studies

The COVID-19 pandemic continues to cause critical illness and deaths internationally. Up to 31 May 2020, mortality in patients admitted to intensive care units (ICU) with COVID-19 was 41.6%. Since then, changes in therapeutics and management may have improved outcomes. Also, data from countries affected later in the pandemic are now available. We searched MEDLINE, Embase, PubMed and Cochrane databases up to 30 September 2020 for studies reporting ICU mortality among adult patients with COVID-19 and present an updated systematic review and meta-analysis. The primary outcome measure was death in intensive care as a proportion of completed ICU admissions, either through discharge from intensive care or death. We identified 52 observational studies including 43,128 patients, and first reports from the Middle East, South Asia and Australasia, as well as four national or regional registries. Reported mortality was lower in registries compared with other reports. In two regions, mortality differed significantly from all others, being higher in the Middle East and lower in a single registry study from Australasia. Although ICU mortality (95%CI) was lower than reported in June (35.5% (31.3-39.9%) vs. 41.6% (34.0-49.7%)), the absence of patient-level data prevents a definitive evaluation. A lack of standardisation of reporting prevents comparison of cohorts in terms of underlying risk, severity of illness or outcomes. We found that the decrease in ICU mortality from COVID-19 has reduced or plateaued since May 2020 and note the possibility of some geographical variation. More standardisation in reporting would improve the ability to compare outcomes from different reports.

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.

Impact of a clinical pharmacist on ultrasound-guided venous thromboembolism screening in hospitalized COVID-19 patients: a pilot prospective study

Background

The recognition, prevention and treatment of venous thromboembolism (VTE) remains a major challenge in the face of the recent COVID-19 pandemic which has been associated with significant cardiovascular, renal, respiratory and hematologic complications related to hypercoagulability. There has been little literature thus far on the utility of screening ultrasound and the role of the clinical pharmacist in treating these patients.

Methods

We present a prospective pilot program of thirty-one consecutive COVID-19 patients who were provided four extremity screening ultrasounds for VTE on admission. This was coordinated by a clinical pharmacist as part of a multidisciplinary approach. Quantitative and qualitative data were recorded with the goal of describing the utility of the clinical pharmacist in ultrasound screening. Data collected include demographics, information on clinical symptoms or signs at presentation, and laboratory and radiologic results during the hospitalization from each individual electronic medical record.

Results

Nine of the thirty-one patients presented with VTE. Of the nine patients, there were twenty-two total clotted vessels, all of which were asymptomatic. The clinical pharmacist, as the coordinator for a multidisciplinary COVID-19 associated coagulopathy management team, drafted a screening and treatment protocol for anticoagulation prophylaxis and therapy of VTE after ultrasound findings.

Conclusion

VTE screening of hospitalized COVID-19 patients reveals a significant number of asymptomatic VTEs and justifies diagnostic, prophylactic, and treatment measures coordinated by a clinical pharmacist.

COVID-19 and venous thromboembolism: Known and unknown for imaging decisions

As we continue to fight against the current coronavirus disease-2019 (COVID-19) pandemic, healthcare professionals across the globe are trying to answer questions surrounding how to best help patients with the up-to-date available science while awaiting the development of new therapies and mass vaccination. Since early in the pandemic, studies indicated a heightened risk of venous thromboembolism (VTE) in COVID-19 infected patients. There have been differing expert opinions about how to assess pretest probability of VTE in this patient population. This has been partly due to the high prevalence of respiratory failure in this patient population and the use of D-dimer as a prognostic test which is also frequently elevated in patients with COVID-19 in absence of VTE. Some experts have argued for an approach similar to usual care with testing if clinical suspicion is high enough. Some have argued for more routine screening at different points of care. Others have even suggested empiric therapeutic anti-coagulation in moderate to severely ill COVID-19 patients. In the following article, we review and summarize the most current literature in hopes of assisting clinicians in decision making and guidance for when to be concerned for VTE in COVID-19 patients. We also discuss research gaps and share pathways currently being used within our institution.

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).

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

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

COVID-19 vasculitis and novel vasculitis mimics

COVID-19 has been occasionally linked to histologically confirmed cutaneous vasculitis and a Kawasaki-like vasculitis, with these entities generally having minimal or no lung involvement and a good prognosis. Unlike these vasculitis types, patients with severe COVID-19 pneumonia can develop cutaneous vasculitis-like lesions and systemic arterial and venous thromboemboli, including cryptogenic strokes and other vasculopathy features. Proposed underlying mechanisms for these severe manifestations have encompassed immune dysregulation, including an anti-phospholipid syndrome-like state, complement activation, viral dissemination with direct systemic endothelial infection, viral RNAaemia with immunothrombosis, clotting pathway activation mediated by hypoxaemia, and immobility. In this Viewpoint, we highlight how imaging and post-mortem findings from patients with COVID-19 indicate a novel thrombosis in the pulmonary venous territory distal to the alveolar capillary bed, a territory that normally acts as a clot filtration system, which might represent an unappreciated nidus for systemic microembolism. Additionally, we suggest that this mechanism represents a novel vasculitis mimic related to COVID-19 that might lead to cryptogenic strokes across multivessel territories, acute kidney injury with haematuria, a skin vasculitis mimic, intestinal ischaemia, and other organ ischaemic manifestations. This finding is supported by pathological reports of extensive pulmonary venular thrombosis and peripheral organ thrombosis with pauci-immune cellular infiltrates. Therefore, severe COVID-19 pneumonia with extensive pulmonary intravascular coagulopathy might help to explain the numerous systemic complications of COVID-19, in which the demonstration of direct organ infection has not adequately explained the pathology.

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.

Role of Complete Duplex Ultrasound to Diagnose Deep Vein Thrombosis in COVID-19 Critical Patients

An increased risk of deep vein thrombosis (DVT) has been reported in critical COVID-19 patients, despite adequate thromboprophylaxis, and most of DVT are probably asymptomatic. As a screening approach has been advocated, the best examination protocol is unknown. The objective of this study is to assess the role of a Complete Duplex Ultrasound (CDUS) examination in detecting DVT in a large population of COVID-19 patients admitted to intensive care unit (ICU) for respiratory failure. Single-center retrospective study of 145 COVID-19 patients admitted to ICU. DVT was assessed with a CDUS performed by experienced radiologist after ICU admission. DVT was confirmed in 38 patients (26%). Most DVT were distal to the knee (66%), while only 16% were proximal. At the time of the examination, 55% of the patients received full-dose anticoagulation, while 45% received thromboprophylaxis, and there were no differences in anticoagulation regimen between positive and negative patients. Patients with DVT had higher dimers compared with those with negative CDUS (P < .002). The observed frequency of DVT is high despite adequate anticoagulation. A comprehensive and experienced ultrasound examination protocol can allow to recognize a large number of distal DVT otherwise missed, albeit their clinical significance is unknown.

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/.

Incidence of venous thromboembolism among patients with severe COVID-19 requiring mechanical ventilation compared to other causes of respiratory failure: a prospective cohort study

Previous studies have suggested that COVID-19 pneumonia is associated with an increased risk of venous thromboembolism (VTE). This study aimed to investigate the incidence of VTE among mechanically ventilated adults with COVID-19 pneumonia, compared to patients with respiratory failure related to other causes. Prospective study that enrolled critically ill adults with suspected COVID-19 pneumonia between June 2, 2020 and August 11, 2020. Critically ill adults with suspected COVID-19 pneumonia who required mechanical ventilation within 24 h after hospital admission were followed until death or hospital discharge. Sequential ultrasonography screening of the lower extremities and catheter insertion sites, as well as testing for plasma biochemical markers, were performed at the intensive care unit admission, day 3, day 7, and day 14. The primary outcome was a composite of deep venous thrombosis, pulmonary embolism, and thrombosis at the central catheter insertion sites. We enrolled 70 patients, including 57 patients with COVID-19 and 13 patients without COVID-19, and all patients completed follow-up. The incidence of the primary outcome was higher among patients with COVID-19 than among patients with respiratory failure related to other etiologies (36.8% vs. 0%, p = 0.023). Multivariate regression analysis revealed that VTE was independently associated with a COVID-19 diagnosis (odds ratio: 6.28, 95% confidence interval: 1.19–68.07) and D-dimer concentration (1-ng/mL increase, odds ratio: 1.15, 95% confidence interval: 1.05–1.30). The incidence of VTE was higher among critically ill mechanically ventilated patients, relative to among patients with respiratory failure related to other causes.

Incidence, risk factors, and thrombotic load of pulmonary embolism in patients hospitalized for COVID-19 infection

OBJECTIVE

To determine the incidence, characteristics, and risk factors of pulmonary embolism (PE) among patients hospitalized for COVID-19.

PATIENTS AND METHODS

We performed a prospective observational study of a randomly selected cohort of consecutive patients hospitalized for COVID-19 infection between March 8, 2020 through April 25, 2020. All eligible patients underwent a computed tomography pulmonary angiography independently of their PE clinical suspicion and were pre-screened for a baseline elevated D-dimer level.

RESULTS

119 patients were randomly selected from the 372 admitted to one tertiary hospital in Valencia (Spain) for COVID-19 infection during the period of study. Seventy-three patients fulfilled both the inclusion criteria and none of the exclusion criteria and were finally included in the study. Despite a high level of pharmacological thromboprophylaxis (89%), the incidence of PE was 35.6% (95% confidence interval [CI], 29.6 to 41.6%), mostly with a peripheral location and low thrombotic load (Qanadli score 18.5%). Multivariate analysis showed that heart rate (Hazard Ratio [HR], 1.04), room-air oxygen saturation (spO2) (HR, 0.87), D-dimer (HR, 1.02), and C-reactive protein (CRP) levels (HR, 1.01) at the time of admission were independent predictors of incident PE during hospitalization. A risk score was constructed with these four variables showing a high predictive value of incident PE (AUC-ROC: 0.86; 95% CI: 0.80 to 0.93).

CONCLUSIONS

Our findings confirmed a high incidence of PE in hospitalized COVID-19 patients. Heart rate, spO2, D-dimer, and CRP levels at admission were associated with higher rates of PE during hospitalization.

Coagulation disorders and thromboembolic disease in COVID-19: review of current evidence in search of a better approach

The new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been an unprecedented global health problem, causing more than 20 million infections and more than 900,000 deaths (September 2020). The SARS-CoV-2 infection, known as COVID-19, has various clinical presentations, from asymptomatic or mild catarrhal processes to severe pneumonia that rapidly progresses to acute respiratory distress syndrome (ARDS) and multiple organ failure. In the last few months, much scientific literature has been devoted to descriptions of different aspects of the coagulation disorders and arterial and venous thrombotic complications associated with COVID-19, particularly venous thromboembolism (VTE). These studies have revealed that SARS-CoV-2 could lead to a prothrombotic state reflecting the high cumulative incidence of associated thrombotic events, particularly in patients admitted to intensive care units (ICUs). As regards the coagulopathy observed in association with SARS-CoV-2 infection, the mechanisms that activate coagulation have been hypothesized as being linked to immune responses, through the release of pro-inflammatory mediators that interact with platelets, stimulate the expression of tissue factor, induce an upregulation of plasminogen activator inhibitor-1, suppress the fibrinolytic system and lead to endothelial dysfunction, triggering thrombogenesis. D-dimer elevation has been recognized as a useful biomarker of poor prognosis, although the best cut-off point for predicting VTE in COVID-19 patients has still not been clarified. This review will try to update all the available scientific information on this important topic with enormous clinical and therapeutic implications.

Caging the dragon: Research approach to COVID-19-related thrombosis

The incidence of venous thrombosis, mostly pulmonary embolism (PE), ranging from local immunothrombosis to central emboli, but also deep vein thrombosis (DVT) in people with coronavirus disease 2019 (COVID-19) is reported to be remarkably high. The relevance of better understanding, predicting, treating, and preventing COVID-19-associated venous thrombosis meets broad support, as can be concluded from the high number of research, review, and guideline papers that have been published on this topic. The Dutch COVID & Thrombosis Coalition (DCTC) is a multidisciplinary team involving a large number of Dutch experts in the broad area of venous thrombosis and hemostasis research, combined with experts on virology, critically ill patients, pulmonary diseases, and community medicine, across all university hospitals and many community hospitals in the Netherlands. Within the consortium, clinical data of at least 5000 admitted COVID-19-infected individuals are available, including substantial collections of biobanked materials in an estimated 3000 people. In addition to considerable experience in preclinical and clinical thrombosis research, the consortium embeds virology-hemostasis research models within unique biosafety facilities to address fundamental questions on the interaction of virus with epithelial and vascular cells, in relation to the coagulation and inflammatory system. The DCTC has initiated a comprehensive research program to answer many of the current questions on the pathophysiology and best anticoagulant treatment of COVID-19-associated thrombotic complications. The research program was funded by grants of the Netherlands Thrombosis Foundation and the Netherlands Organization for Health Research and Development. Here, we summarize the design and main aims of the research program.

Pulmonary Embolism and Deep Vein Thrombosis in COVID-19: A Systematic Review and Meta-Analysis

Background The association of pulmonary embolism (PE) with deep vein thrombosis (DVT) in patients with coronavirus disease 2019 (COVID-19) remains unclear, and the diagnostic accuracy of D-dimer tests for PE is unknown. Purpose To conduct meta-analysis of the study-level incidence of PE and DVT and to evaluate the diagnostic accuracy of D-dimer tests for PE from multicenter individual patient data. Materials and Methods A systematic literature search identified studies evaluating the incidence of PE or DVT in patients with COVID-19 from January 1, 2020, to June 15, 2020. These outcomes were pooled using a random-effects model and were further evaluated using metaregression analysis. The diagnostic accuracy of D-dimer tests for PE was estimated on the basis of individual patient data using the summary receiver operating characteristic curve. Results Twenty-seven studies with 3342 patients with COVID-19 were included in the analysis. The pooled incidence rates of PE and DVT were 16.5% (95% CI: 11.6, 22.9; I2 = 0.93) and 14.8% (95% CI: 8.5, 24.5; I2 = 0.94), respectively. PE was more frequently found in patients who were admitted to the intensive care unit (ICU) (24.7% [95% CI: 18.6, 32.1] vs 10.5% [95% CI: 5.1, 20.2] in those not admitted to the ICU) and in studies with universal screening using CT pulmonary angiography. DVT was present in 42.4% of patients with PE. D-dimer tests had an area under the receiver operating characteristic curve of 0.737 for PE, and D-dimer levels of 500 and 1000 μg/L showed high sensitivity (96% and 91%, respectively) but low specificity (10% and 24%, respectively). Conclusion Pulmonary embolism (PE) and deep vein thrombosis (DVT) occurred in 16.5% and 14.8% of patients with coronavirus disease 2019 (COVID-19), respectively, and more than half of patients with PE lacked DVT. The cutoffs of D-dimer levels used to exclude PE in preexisting guidelines seem applicable to patients with COVID-19. © RSNA, 2020 Supplemental material is available for this article. See also the editorial by Woodard in this issue.

Global Impact of Coronavirus Disease 2019 Infection Requiring Admission to the ICU: A Systematic Review and Meta-analysis

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has placed unprecedented burden on the delivery of intensive care services worldwide.

RESEARCH QUESTION

What is the global point estimate of deaths and risk factors for patients who are admitted to ICUs with severe COVID-19?

STUDY DESIGN AND METHODS

In this systematic review and meta-analysis Medline, Embase, and the Cochrane library were searched up to August 1, 2020. Pooled prevalence of participant characteristics, clinical features, and outcome data was calculated with the use of random effects models. Subgroup analyses were based on geographic distribution, study type, quality assessment, sample size, end date, and patient disposition. Studies that reported in-hospital mortality rate of adult patients (age >18 years) with confirmed COVID-19 admitted to an ICU met study eligibility criteria. Critical evaluation was performed with the Newcastle Ottawa Scale for nonrandomized studies.

RESULTS

Forty-five studies with 16,561 patients from 17 countries across four continents were included. Patients with COVID-19 who were admitted to ICUs had a mean age of 62.6 years (95% CI, 60.4-64.7). Common comorbidities included hypertension (49.5%; 95% CI, 44.9-54.0) and diabetes mellitus (26.6%; 95% CI, 22.7-30.8). More than three-quarters of cases experienced the development of ARDS (76.1%; 95% CI, 65.7-85.2). Invasive mechanical ventilation was required in 67.7% (95% CI, 59.1-75.7) of case, vasopressor support in 65.9% (95% CI, 52.4-78.4) of cases, renal replacement therapy in 16.9% (95% CI, 12.1-22.2) of cases, and extracorporeal membrane oxygenation in 6.4% (95% CI, 4.1-9.1) of cases. The duration of ICU and hospital admission was 10.8 days (95% CI, 9.3-18.4) and 19.1 days (95% CI, 16.3-21.9), respectively, with in-hospital mortality rate of 28.1% (95% CI, 23.4-33.0; I2 = 96%). No significant subgroup effect was observed.

INTERPRETATION

Critically ill patients with COVID-19 who are admitted to the ICU require substantial organ support and prolonged ICU and hospital level care. The pooled estimate of global death from severe COVID-19 is <1 in 3.