Prevalence of thromboembolic events and status of prophylactic anticoagulant therapy in hospitalized patients with COVID-19 in Japan

A systematic review of thromboembolic complications and outcomes in hospitalised COVID-19 patients

Thromboembolic (TE) complications [myocardial infarction (MI), stroke, deep vein thrombosis (DVT), and pulmonary embolism (PE)] are common causes of mortality in hospitalised COVID-19 patients. Therefore, this review was undertaken to explore the incidence of TE complications and mortality associated with TE complications in hospitalised COVID-19 patients from different studies. A literature search was performed using ScienceDirect and PubMed databases using the MeSH term search strategy of "COVID-19", "thromboembolic complication", "venous thromboembolism", "arterial thromboembolism", "deep vein thrombosis", "pulmonary embolism", "myocardial infarction", "stroke", and "mortality". There were 33 studies included in this review. Studies have revealed that COVID-19 patients tend to develop venous thromboembolism (PE:1.0-40.0% and DVT:0.4-84%) compared to arterial thromboembolism (stroke:0.5-15.2% and MI:0.8-8.7%). Lastly, the all-cause mortality of COVID-19 patients ranged from 4.8 to 63%, whereas the incidence of mortality associated with TE complications was between 5% and 48%. A wide range of incidences of TE complications and mortality associated with TE complications can be seen among hospitalized COVID-19 patients. Therefore, every patient should be assessed for the risk of thromboembolic complications and provided with an appropriate thromboprophylaxis management plan tailored to their individual needs.

Association of interleukin-6, ferritin, and lactate dehydrogenase with venous thromboembolism in COVID-19: a systematic review and meta-analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) is frequntly accompanied by venous thromboembolism (VTE), and its mechanism may be related to the abnormal inflammation and immune status of COVID-19 patients. It has been proved that interleukin-6 (IL-6), ferritin and lactate dehydrogenase (LDH) may play an important role in the occurrence of VTE in COVID-19 infection. But whether they can server as predictors for VTE in COVID-19 is still unclear. In this study, we performed a systematic review and meta-analysis to compare IL-6, ferritin and LDH in VTE and non-VTE COVID-19 patients in order to shed light on the prevention and treatment of VTE.

METHODS

Related literatures were searched in PubMed, Embase, Web of Science, Google Scholar, China National Knowledge Infrastructure (CNKI), WANGFANG. COVID-19 patients were divided into VTE group and non-VTE group. Meta-analysis was then conducted to compare levels of IL-6, ferritin and LDH between the two groups.

RESULTS

We finally included and analyzed 17 literatures from January 2019 to October 2022. There was a total of 7,035 COVID-19 patients, with a weighted mean age of 60.01 years. Males accounted for 62.64% and 61.34% patients were in intensive care unit (ICU). Weighted mean difference (WMD) of IL-6, ferritin and LDH was 31.15 (95% CI: 9.82, 52.49), 257.02 (95% CI: 51.70, 462.33) and 41.79 (95% CI: -19.38, 102.96), respectively. The above results indicated that than compared with non-VTE group, VTE group had significantly higher levels of IL-6 and ferritin but similar LDH.

CONCLUSION

This systematic review and meta-analysis pointed out that elevated levels of IL-6 and ferritin were significantly possitive associated with VTE, thus could be used as biological predictive indicators of VTE among COVID-19 patients. However, no association was found between level of LDH and VTE. Therefore, close monitoring of changes in IL-6 and ferritin concentrations is of great value in assisting clinicans to rapidly identify thrombotic complications among COVID-19 patients, hence facilitating the timely effective managment. Further studies are required in terms of the clinical role of cytokines in the occurrence of VTE among COVID-19 infection, with more reliable systematic controls and interventional trials.

Role of Fibrin Monomer Complex in Coronavirus Disease 2019 for Venous Thromboembolism and the Prognosis

Objective Venous thromboembolism (VTE) is a common complication of severe coronavirus disease 2019 (COVID-19) and is associated with its prognosis. The fibrin monomer complex (FMC), a marker of thrombin generation, is reportedly useful in diagnosing acute thrombosis. To date, there has been only one report on FMC in COVID-19, and the usefulness of FMC in COVID-19 is unknown. We therefore evaluated the frequency of VTE in non-intensive-care unit COVID-19 patients in Japan and determine the clinical utility of FMC in COVID-19. Methods This was a single-center retrospective study. Laboratory test results and outcomes (thrombosis and severe progression of COVID-19) were obtained via medical record review. We assessed the relationship between FMC and VTE incidence and evaluated the association between elevated FMC levels and severe progression of COVID-19. Patients This study included 247 patients with COVID-19 who were hospitalized between December 2020 and September 2021 and had had their levels of D-dimer and FMC measured. Results Of the 247 included patients, 3 (1.2%) developed VTE. All three had elevated FMC levels on admission; however, the D-dimer level was not elevated in one case on admission. The FMC level was significantly higher in the group with severe COVID-19 progression than in the group without severe progression. A multivariate analysis showed that severe progression was associated with elevated FMC levels (odds ratio, 7.40; 95% confidence interval, 2.63-22.98; p<0.001). Conclusion FMC can be useful for diagnosing VTE in the acute phase of COVID-19. Elevated FMC was found to be associated with severity on admission and severe progression.

Exploring heterogeneity in reported venous thromboembolism risk in COVID-19 and comparison to other viral pneumonias: a systematic review and meta-regression

Background

Sources of heterogeneity in venous thromboembolism (VTE) risk in COVID-19 are unclear and comparisons to other viruses are lacking.

Objectives

To describe VTE risk in patients with COVID-19, explore sources of heterogeneity, and make comparisons with other viral pneumonia.

Methods

PubMed and Embase data were searched on March 14, 2021, for studies on VTE in adults hospitalized with viral pneumonia. VTE risk estimates were pooled in a random effects meta-analysis stratified by virus type. Heterogeneity in COVID-19 was explored in multivariable meta-regression.

Results

Seventy studies in COVID-19 (intensive care [ICU] [47] vs ward [23]), 4 studies in seasonal influenza (ICU [3] vs ward [1]), 2 ICU studies in H1N1 and 1 ICU study in SARS-CoV-1 were included. For COVID-19 ICU, pooled VTE risk was 19.6% (95% confidence interval [CI], 16.2%-23.5; I2 = 92.8%) for nonscreening studies and 30.0% (95% CI, 17.9%-45.7%; I2 = 81.9%) for screening studies. For COVID-19 ward, pooled VTE risk was 3.4% (95% CI, 2.4%-4.7%; I2 = 91.3%) and 22.5% (95% CI, 10.2%-42.7%; I2 = 91.6%) for nonscreening and screening studies, respectively. Higher sample size was associated with lower VTE risk. Pooled VTE risk in seasonal influenza and H1N1 at ICU were 9.0% (95% CI, 5.6%-14.2%; I2 = 39.7%) and 29.2% (95% CI, 8.7%-64.2%; I2 = 77.9%), respectively. At ward, VTE risk of seasonal influenza was 2.4% (95% CI, 2.1%-2.7%). In SARS-CoV-1, VTE risk was 47.8% (95% CI, 34.0-62.0).

Conclusion

Pooled risk estimates in COVID-19 should be interpreted cautiously as a high degree of heterogeneity is present, which hinders comparison to other viral pneumonia. The association of VTE risk in COVID-19 to sample size suggests publication bias.

Real-World Management of Pharmacological Thromboprophylactic Strategies for COVID-19 Patients in Japan: From the CLOT-COVID Study

Background

Data on prophylactic anticoagulation are important in understanding the current issues, unmet needs, and optimal management of Japanese COVID-19 patients.

Objectives

This study aimed to investigate the clinical management strategies for prophylactic anticoagulation of COVID-19 patients in Japan.

Methods

The CLOT-COVID study was a multicenter observational study that enrolled 2,894 consecutive hospitalized patients with COVID-19. The study population consisted of 2,889 patients (after excluding 5 patients with missing data); it was divided into 2 groups: patients with pharmacological thromboprophylaxis (n = 1,240) and those without (n = 1,649). Furthermore, we evaluated the 1,233 patients who received prophylactic anticoagulation-excluding 7 patients who could not be classified based on the intensity of their anticoagulants-who were then divided into 2 groups: patients receiving prophylactic anticoagulant doses (n = 889) and therapeutic anticoagulant doses (n = 344).

Results

The most common pharmacological thromboprophylaxis anticoagulant was unfractionated heparin (68.2%). The severity of COVID-19 at admission was a predictor of the implementation of pharmacological thromboprophylaxis in the multivariable analysis (moderate vs mild: OR: 16.6; 95% CI:13.2-21.0; P < 0.001, severe vs mild: OR: 342.6, 95% CI: 107.7-1090.2; P < 0.001). It was also a predictor of the usage of anticoagulants of therapeutic doses in the multivariable analysis (moderate vs mild: OR: 2.10; 95% CI: 1.46-3.02; P < 0.001, severe vs mild: OR: 5.96; 95% CI: 3.91-9.09; P < 0.001).

Conclusions

In the current real-world Japanese registry, pharmacological thromboprophylaxis, especially anticoagulants at therapeutic doses, was selectively implemented in COVID-19 patients with comorbidities and severe COVID-19 status at admission.

A novel anticoagulation treatment protocol using unfractionated heparin for coronavirus disease 2019 patients in Japan, 2022

Hypercoagulability, which can be induced by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays an important role in the pathogenesis of coronavirus disease 2019 (COVID-19). Although anticoagulation therapy is expected to decrease the incidence of thrombosis and mortality in COVID-19 patients, the optimal use of anticoagulation therapy has not been established, especially using unfractionated heparin (UFH). Herein, we suggest a new anticoagulation treatment protocol for the use of UFH in Japanese COVID-19 patients. This protocol considers the safety regarding UFH usage, to lower major bleeding events, and reflects the latest evidence and the current situation regarding anticoagulation therapy in Japan.

Incidence of thromboembolic complications in hospitalized COVID-19 patients in a medical ward in Japan: A single-center retrospective and prospective observational study

BACKGROUND

A high incidence of thromboembolic complications is one of the hallmarks of COVID-19. However, there may be a difference in the incidence of thromboembolic complications between Asian and Western people. In addition, few prospective studies have been conducted to determine the incidence of thromboembolic complications in hospitalized COVID-19 patients in medical wards in Japan.

METHODS

A single-center retrospective and prospective cohort study was conducted to determine the incidence of thromboembolic complications in symptomatic COVID-19 patients in a medical ward in a Japanese hospital. All 1116 consecutive COVID-19 patients who were admitted to our hospital from November 1, 2020, to October 26, 2021, were included. The primary outcome was any thromboembolic complications, which included venous thromboembolism, myocardial infarction, ischemic stroke, and other arterial embolisms.

RESULTS

The median patient age was 50 (IQR, 37-61), 402 (36.0%) were women, 1005 (90.1%) were Japanese, the median body mass index was 24.1 (IQR, 21.6-27.2), and 43 (3.9%) had Padua scores of at least 4 points at admission. Regarding the severity of COVID-19, 543 (48.7%), 315 (28.2%), 204 (18.3%), and 54 (4.8%) patients had mild, moderate, severe, and critical COVID-19, respectively. Nine patients (0.8%) died, and 47 patients (4.2%) were transferred to other hospitals for intensive care. The primary outcome occurred in only 5 patients (0.5%; 95% CI, 0.1-0.8) and consisted of 3 ischemic strokes, 2 limb ischemia events, and one asymptomatic pulmonary embolism. Even in the 204 patients with severe COVID-19, the prevalence of thromboembolic complications was only 2.5% (95% CI, 0.3-4.6).

CONCLUSION

Thromboembolic complications of COVID-19 are rare even in severe cases in a medical ward in a Japanese hospital. Further studies are needed to identify severe COVID-19 patients with a higher risk for thromboembolic complications in Japan.

The incidence and clinical impact of thrombotic events in hospitalised Coronavirus disease 2019 illness

BACKGROUND

Coronavirus disease-2019(COVID-19) infection and thrombosis are of great clinical importance as this association has shown to increase mortality. We intend to estimate the incidence of thrombotic events(TE) and their impact on clinical outcomes in hospitalised COVID-19 patients.

METHODS

This was an analytical cross-sectional study. The study population comprised of hospitalised COVID-19 patients between 1st March 2021 and 31st May 2021. The clinico-demographic data, thrombotic events, and clinical outcomes were collected from electronic health records.

RESULTS

A total of 1274 patients were analysed. The median age of the study population was 56 years (IQR:44-66 years). The estimated incidence of TE was 5.8%(n=74); 60.8% of these TE occurred in patients having severe/critical COVID-19 illness and 70.3% of TE occurred in patients in the intensive care unit. Venous events(3.9%) were common compared to arterial events(1.9%). On multivariate logistic regression analysis, total leukocyte count, C-reactive protein, and D-dimer level were found to be the independent predictors of having TE. Receiver operator curve revealed a cut-off point of 872.5 DDU μg/L for D-dimer level (sensitivity:67.6% and specificity:72.1%; p<0.001, area under curve=0.78) for predicting TE. Patients with TE had significantly higher mortality compared to those without TE (58.1% vs 22.2%; p<0.001); and the presence of TE (OR=2.94; 95% CI:1.7-5.1, p<0.001) was found to be the independent predictor of mortality.

CONCLUSIONS

The incidence of TE is high for hospitalised COVID-19 patients and it is even higher in severe/critical COVID illness. Its presence has shown to double the mortality compared to those without it.

The current status of thrombosis and anticoagulation therapy in patients with COVID-19 in Japan: From the CLOT-COVID study

Background

Data on thrombosis and current real-world management strategies for anticoagulation therapy are scarce but important for understanding current issues and unmet needs of an optimal management of patients with coronavirus disease 2019 (COVID-19).

Method

The CLOT-COVID Study (thrombosis and antiCoaguLatiOn Therapy in patients with COVID-19 in Japan Study: UMIN000045800) was a retrospective, multicenter cohort study enrolling consecutive hospitalized patients with COVID-19 among 16 centers in Japan from April 2021 to September 2021, and we tried to capture the status of the patients in the fourth and fifth waves of the COVID-19 infections in Japan. We enrolled consecutive hospitalized patients who were diagnosed with COVID-19 and had a positive polymerase chain reaction test obtained from the hospital databases.

Results

Among 2894 patients with COVID-19, 1245 (43%) received pharmacological thromboprophylaxis. The proportion of pharmacological thromboprophylaxis increased according to the severity of the COVID-19 in 9.8% with mild COVID-19, 61% with moderate COVID-19, and 97% with severe COVID-19. The types and doses of anticoagulants varied widely across the participating centers. During the hospitalization, 38 patients (1.3%) and 126 (4.4%) underwent ultrasound examinations for the lower extremities and contrast-enhanced computed tomography examinations, respectively, and 55 (1.9%) developed thrombosis, mostly venous thromboembolism (71%). The incidence of thrombosis increased according to the severity of the COVID-19 in 0.2% with mild COVID-19, 1.4% with moderate COVID-19, and 9.5% with severe COVID-19. Major bleeding occurred in 57 patients (2.0%) and 158 (5.5%) died, and 81% of them were due to respiratory failure from COVID-19 pneumonia.

Conclusions

In the present large-scale observational study, pharmacological thromboprophylaxis for hospitalized patients with COVID-19 was common especially in patients with severe COVID-19, and management strategies varied widely across the participating centers. The overall incidence of thrombosis was substantially low with an increased incidence according to the severity of the COVID-19.

Association between pre-admission anticoagulation and in-hospital death, venous thromboembolism, and major bleeding among hospitalized COVID-19 patients in Japan

Purpose

The coagulation activation leads to thrombotic complications such as venous thromboembolism (VTE) in patients with coronavirus disease‐2019 (COVID‐19). Prophylactic anticoagulation therapy has been recommended for hospitalized COVID‐19 patients in clinical guidelines. This retrospective cohort study aimed to examine the association between pre‐admission anticoagulation treatment and three outcomes: in‐hospital death, VTE, and major bleeding among hospitalized COVID‐19 patients in Japan.

Methods

Using a large‐scale claims database built by the Medical Data Vision Co. in Japan, we identified patients hospitalized for COVID‐19 who had outpatient prescription data at least once within 3 months before being hospitalized. Exposure was set as pre‐admission anticoagulation treatment (direct oral anticoagulant or vitamin K antagonist), and outcomes were in‐hospital death, VTE, and major bleeding. We conducted multivariable logistic regression analyses, adjusting for a single summarized score (a propensity score of receiving pre‐admission anticoagulation) for VTE and major bleeding, due to the small number of outcomes.

Results

Among the 2612 analytic patients, 179 (6.9%) had pre‐admission anticoagulation. Crude incidence proportions were 13.4% versus 8.5% for in‐hospital death, 0.56% versus 0.58% for VTE, and 2.2% versus 1.1% for major bleeding among patients with and without pre‐admission anticoagulation, respectively. Adjusted odds ratios (95% confidence intervals) were 1.25 (0.75–2.08) for in‐hospital death, 0.21 (0.02–1.97) for VTE, and 2.63 (0.80–8.65) for major bleeding. Several sensitivity analyses did not change the results.

Conclusions

We found no evidence that pre‐admission anticoagulation treatment was associated with in‐hospital death. However, a larger sample size may be needed to conclude its effect on VTE and major bleeding.

Arterial and Venous Thrombosis Complicated in COVID-19: A Retrospective Single Center Analysis in Japan

Background: Thrombosis is a characteristic complication in coronavirus disease 2019 (COVID-19). Since coagulopathy has been observed over the entire clinical course, thrombosis might be a clue to understanding the specific pathology in COVID-19. Currently, there is limited epidemiological data of COVID-19-associated thrombosis in the Japanese population and none regarding variant strains of SARS-CoV-2. Here, we elucidate the risk factors and the pattern of thrombosis in COVID-19 patients. Methods: The patients consecutively admitted to Tokyo Medical and Dental University Hospital with COVID-19 were retrospectively analyzed. SARS-CoV-2 variants of concern/interest (VOC/VOI) carrying the spike protein mutants E484K, N501Y, or L452R were identified by PCR-based analysis. All thrombotic events were diagnosed by clinical symptoms, ultrasonography, and/or radiological tests. Results: Among the 516 patients, 32 patients experienced 42 thromboembolic events. Advanced age, severe respiratory conditions, and several abnormal laboratory markers were associated with the development of thrombosis. While thrombotic events occurred in 13% of the patients with a severe respiratory condition, those events still occurred in 2.5% of the patients who did not require oxygen therapy. Elevated D-dimer and ferritin levels on admission were independent risk factors of thrombosis (adjusted odds ratio 9.39 and 3.11, 95% confidence interval 2.08-42.3, and 1.06-9.17, respectively). Of the thrombotic events, 22 were venous, whereas 20 were arterial. While patients with thrombosis received anticoagulation and antiinflammatory therapies with a higher proportion, the mortality rate, organ dysfunctions, and bleeding complications in these patients were higher than those without thrombosis. The incidence of thrombosis in COVID-19 became less frequent over time, such as during the replacement of the earlier strains of SARS-CoV-2 by VOC/VOI and during increased use of anticoagulatory therapeutics. Conclusion: This study elucidated that elevated D-dimer and ferritin levels are useful biomarkers of thrombosis in COVID-19 patients. The comparable incidence of arterial thrombosis with venous thrombosis and the development of thrombosis in less severe patients required further considerations for the management of Japanese patients with COVID-19. Further studies would be required to identify high-risk populations and establish appropriate interventions for thrombotic complications in COVID-19.

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.