Association Between the Development of Thrombosis and Worsening of Disease Severity in Patients With Moderate COVID-19 on Admission　- From the CLOT-COVID Study.

BACKGROUND: The worsening of coronavirus disease 2019 (COVID-19) severity is a critical issue in current clinical settings and may be associated with the development of thrombosis.Methods and Results: This study used patient data obtained in the CLOT-COVID study, a retrospective multicenter cohort study. The demographics of patients with moderate COVID-19 on admission with and without worsened severity during hospitalization were compared and predictors were identified. Of 927 patients with moderate COVID-19 on admission, 182 (19.6%) had worsened severity during hospitalization. Patients with worsening of severity were older, more likely to have hypertension, diabetes, heart disease, and active cancer, and more likely to use pharmacological thromboprophylaxis. Patients with worsening of severity had higher D-dimer levels on admission and were more likely to develop thrombosis and major bleeding during hospitalization than those without worsening. Increased age (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.01-1.03, P=0.005), diabetes (OR: 1.63, 95% CI: 1.11-2.33, P=0.012), D-dimer levels >1.0 µg/mL on admission (OR: 2.10, 95% CI: 1.45-3.03, P<0.001), and thrombosis (OR: 6.28, 95% CI: 2.72-14.53, P<0.001) were independently associated with worsening of COVID-19 severity. CONCLUSIONS: Approximately 20% of patients with moderate COVID-19 had worsened severity during hospitalization. Increased age, diabetes, D-dimer levels >1.0 µg/mL on admission, and the development of thrombosis during hospitalization were significantly associated with worsened COVID-19 severity.

Mortality-associated Risk Factors in Hospitalized COVID-19 Patients in Japan: Findings of the CLOT-COVID Study.

BACKGROUND: Reports of mortality-associated risk factors in patients with the novel coronavirus disease 2019 (COVID-19) are limited. METHODS: We evaluated the clinical features that were associated with mortality among patients who died during hospitalization (n = 158) and those who were alive at discharge (n = 2,736) from the large-scale, multicenter, retrospective, observational cohort CLOT-COVID study, which enrolled consecutively hospitalized COVID-19 patients from 16 centers in Japan from April to September 2021. Data from 2,894 hospitalized COVID-19 participants of the CLOT-COVID study were analyzed in this study. RESULTS: Patients who died were older (71.1 years vs 51.6 years, P < 0.001), had higher median D-dimer values on admission (1.7 µg/mL vs 0.8 µg/mL, P < 0.001), and had more comorbidities. On admission, the patients who died had more severe COVID-19 than did those who survived (mild: 16% vs 63%, moderate: 47% vs 31%, and severe: 37% vs 6.2%, P < 0.001). In patients who died, the incidence of thrombosis and major bleeding during hospitalization was significantly higher than that in those who survived (thrombosis: 8.2% vs 1.5%, P < 0.001; major bleeding: 12.7% vs 1.4%, P < 0.001). Multivariable logistic regression analysis revealed that age >70 years, high D-dimer values on admission, heart disease, active cancer, higher COVID-19 severity on admission, and development of major bleeding during hospitalization were independently associated with a higher mortality risk. CONCLUSION: This large-scale observational study in Japan identified several independent risk factors for mortality in hospitalized patients with COVID-19 that could facilitate appropriate risk stratification of patients with COVID-19.

Therapeutic-Dose vs. Prophylactic-Dose Anticoagulation Therapy for Critically Ill Patients With COVID-19 in a Practice-Based Observational Study.

BACKGROUND: The potential benefit of therapeutic-dose anticoagulation for critically ill patients with coronavirus disease 2019 (COVID-19) is still controversial.Methods and Results: In the CLOT-COVID study, 225 patients with severe COVID-19 on admission requiring mechanical ventilation or extracorporeal membrane oxygenation were divided into patients with therapeutic-dose anticoagulation (N=110) and those with prophylactic-dose anticoagulation (N=115). There was no significant difference in the incidence of thrombosis between the groups (9.1% vs. 7.8%, P=0.73). CONCLUSIONS: Among a cohort of critically ill patients with COVID-19, approximately half received therapeutic-dose anticoagulation, although it did not show a potential benefit compared with prophylactic-dose anticoagulation.

Incidence, risk factors, and clinical impact of major bleeding in hospitalized patients with COVID-19: a sub-analysis of the CLOT-COVID Study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) causes extensive coagulopathy and a potential benefit of anticoagulation therapy has been documented for prevention of thromboembolic events. Bleeding events has also been reported as a notable complication; whereas, the incidence, risks, and clinical impact of bleeding remain unclear. METHOD: The CLOT-COVID Study was a nationwide, retrospective, multicenter cohort study on consecutive hospitalized patients with COVID-19 in Japan between April 2021 and September 2021. In this sub-analysis, we compared the characteristics of patients with and without major bleeding; moreover, we examined the risk factors for and clinical impact of bleeding events. RESULTS: Among 2882 patients with COVID-19, 57 (2.0%) had major bleeding. The incidence of major bleeding increased with COVID-19 severity as follows: 0.5%, 2.3%, and 12.3% in patients with mild, moderate, and severe COVID-19, respectively. COVID-19 severity, history of major bleeding, and anticoagulant type/dose were independently and additively associated with the bleeding incidence. Compared with patients without major bleeding, those with major bleeding exhibited a longer duration of hospitalization (9 [6-14] vs 28 [19-43] days, P < 0.001) and higher mortality during hospitalization (4.9% vs. 35.1%, P < 0.001). CONCLUSIONS: In the real-world clinical practice, the incidence of major bleeding was not uncommon, especially in patients with severe COVID-19. Independent risk factors for major bleeding included history of major bleeding, COVID-19 severity, and anticoagulant use, which could be associated with poor clinical outcomes including higher mortality. Precise recognition of the risks for bleeding may be helpful for an optimal use of anticoagulants and for better outcomes in patients with COVID-19.

An International Delphi Consensus on Diagnostic Criteria for Buerger's Disease.

BACKGROUND: Buerger's disease (BD) remains a debilitating condition. Despite multiple published diagnostic criteria for BD, none is universally accepted as a gold standard. METHODS: We conducted a 2-round modified Delphi consensus study to establish a consensus on the diagnostic. The questionnaire included statements from several commonly used diagnostic criteria for BD. Qualitative and quantitative analysis methods were performed. An agreement level of 70% was applied. RESULTS: Twenty nine experts from 18 countries participated in this study. Overall, 75 statements were circulated in Round 1. Of these, 28% of statements were accepted. Following comments, 21 statements were recirculated in Round 2 and 90% were accepted. Although more than 90% of the experts did not agree that the diagnosis of BD can be based only on clinical manifestation, none of the nonclinical manifestations of BD were agreed as a part of the diagnostic criteria. There was an agreement that a history of tobacco consumption in any form, not necessarily confined to the current use, should be a part of the diagnostic criteria of BD. The history of thrombophlebitis migrans, even if not present at presentation, was accepted as a clue for BD diagnosis. It was also agreed that discoloration of the toes or fingers could be included in the diagnostic criteria of BD. Experts agreed that histology results could differentiate BD from atherosclerosis obliterans and other types of vasculitis. The presence of corkscrew collaterals on imaging and burning pain reached the agreement at the first round but not at the second. There was no consensus regarding age cut-off, the requirement of normal lipid profile, and normal blood glucose for BD diagnosis. CONCLUSIONS: The present study demonstrated discrepancies in the various published diagnostic criteria for BD and their selective utilization in routine clinical practice worldwide. We propose that all published diagnostic criteria for BD be re-evaluated for harmonization and universal use.

Clinical Features of Venous Thromboembolism in Patients With Coronavirus Disease 2019 (COVID-19) in Japan　- A Case Series Study.

BACKGROUND: Suspicion that the coronavirus disease 2019 (COVID-19) caused venous thromboembolism (VTE).Methods and Results:We conducted a case series study of 5 VTE patients with COVID-19 in Japan. The median body mass index was 27.7 kg/m2, and all patients required mechanical ventilation during hospitalization. Patients were diagnosed as VTE in the intensive care unit (ICU), general ward, and outpatient ward. CONCLUSIONS: The current case series study revealed some clinical features of VTE patients with COVID-19 in Japan, including obese patients and those requiring mechanical ventilation during hospitalization, who should be followed closely for VTE, even after leaving the ICU.

Incidence and Clinical Features of Venous Thromboembolism in Hospitalized Patients With Coronavirus Disease 2019 (COVID-19) in Japan.

BACKGROUND: Coronavirus disease 2019 (COVID-19) reportedly causes venous thromboembolism (VTE), but the status of this complication in Japan was unclear.Methods and Results:The VTE and COVID-19 in Japan Study is a retrospective, multicenter cohort study enrolling hospitalized patients with COVID-19 who were evaluated with contrast-enhanced computed tomography (CT) examination at 22 centers in Japan between March 2020 and October 2020. Among 1,236 patients with COVID-19, 45 (3.6%) were evaluated with contrast-enhanced CT examination. VTE events occurred in 10 patients (22.2%), and the incidence of VTE in mild, moderate, and severe COVID-19 was 0%, 11.8%, and 40.0%, respectively. COVID-19 patients with VTE showed a higher body weight (81.6 vs. 64.0 kg, P=0.005) and body mass index (26.9 vs. 23.2 kg/m2, P=0.04), and a higher proportion had a severe status for COVID-19 compared with those without. There was no significant difference in the proportion of patients alive at discharge between patients with and without VTE (80.0% vs. 88.6%, P=0.48). Among 8 pulmonary embolism (PE) patients, all were low-risk PE. CONCLUSIONS: Among a relatively small number of patients undergoing contrast-enhanced CT examination in Japanese real-world clinical practice, there were no VTE patients among those with mild COVID-19, but the incidence of VTE seemed to be relatively high among severe COVID-19 patients, although all PE events were low-risk without significant effect on mortality risk.

The Epidemiologic and Clinical Findings of Patients with Buerger Disease.

BACKGROUND: Buerger disease is a nonatherosclerotic peripheral arterial disease, which is mostly observed in young male smokers. Buerger disease is characterized by the observation of peripheral arterial occlusion by angiography. The condition may be caused by microembolization in the small-sized arteries of the distal extremities. Buerger disease is diagnosed based on the Shionoya's clinical diagnostic criteria, which include: (1) a history of smoking, (2) onset before the age of 50 years, (3) the presence of infrapopliteal arterial occlusions, (4) either upper limb involvement or phlebitis migrans, and (5) the absence of atherosclerotic risk factors other than smoking. Several studies have reported that oral bacterial infections (periodontitis) could activate the onset of Buerger disease. In this study, we report the epidemiologic and clinical manifestations of patients with Buerger disease. METHODS: Fifty-eight patients who were surgically treated between July 1989 and June 2014 at Tokyo Medical and Dental University Hospital were enrolled in this study. All of the patients clinically diagnosed with Buerger disease based on Shionoya's clinical diagnostic criteria. Fifty-five male and 3 female patients were treated. The mean age of the patients was 48 years (range, 21-73 years). RESULTS: All of the patients were either smokers or had a history of smoking. The mean Brinkman index score was 780 (range, 150-1,640). Their mean age at the onset of Buerger disease was 38 years (range, 21-50). The arterial lesions extended to the femoral arteries in 25% of cases, to the iliac arteries in 8% and to the abdominal aorta and/or visceral arteries in 6% of cases. Upper limb involvement, including cyanosis, paleness, and gangrene, was obvious in 84% of patients, and phlebitis migrans was recognized in 34%. The lower extremities symptoms involved intermittent claudication in 23% of the patients, rest pain in 13% of the patients, and ulceration or gangrene in 64% of the patients. Fifteen patients had undergone surgical arterial reconstruction, 4 patients had received endovascular therapy, 33 patients had undergone lumbar sympathectomy and 8 patients had undergone thoracic sympathectomy. Twenty percent of the patients needed minor limb amputations, and 4% required major limb amputations. In the patients who were examined for their oral conditions, periodontitis corresponding to grades B (moderate periodontitis), C (severe periodontitis), and D (edentulous patients) was revealed in 31%, 56%, and 13% of the patients, respectively. CONCLUSIONS: More than half of the Buerger disease patients in this study were suffering from severe periodontitis. It is possible that not only the cessation of smoking, but also the improvement of periodontal care could improve the clinical symptoms related to Buerger disease.

Prophylactic Anticoagulation and Thrombosis in Hospitalized Patients with Clinically Stable COVID-19 at Admission: From the Practice-Based Observational Study.

Objectives: The potential benefit of routine prophylactic anticoagulation for all hospitalized patients with clinically stable coronavirus disease 2019 (COVID-19) is still controversial. Method: The CLOT-COVID Study was a multicenter observational study enrolling 2894 consecutive hospitalized patients with COVID-19. The current study population consisted of 1738 hospitalized patients with mild COVID-19 at admission not requiring oxygen administration, who were divided into 2 groups: patients with prophylactic anticoagulation (n = 326) and those without (n = 1412). Results: Patients with prophylactic anticoagulation had more severe status of the worst severity of COVID-19 during hospitalization compared with those without (mild: 38% versus 82%, moderate: 55% versus 17%, and severe or death at discharge: 6.4% versus 0.7%, P <0.001). During hospitalization, 8 patients (0.5%) developed thrombosis, and the incidences of thrombosis were numerically higher in patients with more severe status of worst severity of COVID-19 during hospitalization (mild: 0.2%, moderate: 1.2%, and severe or death at discharge: 3.2%). Conclusions: Among hospitalized patients with clinically stable COVID-19 at admission, patients who did not worsen in COVID-19 severity after admission rarely developed thrombosis, although patients with worsening of COVID-19 severity after admission more often received prophylactic anticoagulation and might have a higher risk of thrombosis.

Influence of obesity on incidence of thrombosis and disease severity in patients with COVID-19: From the CLOT-COVID study.

BACKGROUND: The influence of obesity on the development of thrombosis and severity of coronavirus disease 2019 (COVID-19) remains unclear. METHOD: The CLOT-COVID study was a retrospective multicenter cohort study enrolling 2894 consecutive hospitalized patients with COVID-19 between April 2021 and September 2021 among 16 centers in Japan. The present study consisted of 2690 patients aged over 18 years with available body mass index (BMI), who were divided into an obesity group (BMI ≥30) (N = 457) and a non-obesity group (BMI <30) (N = 2233). RESULTS: The obesity group showed more severe status of COVID-19 at admission compared with the non-obesity group. The incidence of thrombosis was not significantly different between the groups (obesity group: 2.6 % versus non-obesity group: 1.9 %, p = 0.39), while the incidence of a composite outcome of all-cause death, or requirement of mechanical ventilation or extracorporeal membrane oxygenation during hospitalization was significantly higher in the obesity group (20.1 % versus 15.0 %, p < 0.01). After adjusting confounders in the multivariable logistic regression model, the risk of obesity relative to non-obesity for thrombosis was not significant (adjusted OR, 1.39; 95 % CI, 0.68-2.84, p = 0.37), while the adjusted risk of obesity relative to non-obesity for the composite outcome was significant (adjusted OR, 1.85; 95 % CI, 1.39-2.47, p < 0.001). CONCLUSIONS: In the present large-scale observational study, obesity was not significantly associated with the development of thrombosis during hospitalization; however, it was associated with severity of COVID-19.

Significant Impact of Age on Mortality and Non-significant Impact of Age on Thrombosis and Major Bleeding in Patients with COVID-19: From the CLOT-COVID Study.

AIM: There is scarce data on the impact of age on clinical outcomes in patients with coronavirus disease 2019 (COVID-19). METHOD: The CLOT-COVID Study was a retrospective, multicenter cohort study enrolling 2894 consecutive hospitalized patients with COVID-19 among 16 centers in Japan from April 2021 to September 2021. We divided the entire cohort into five groups according to age strata; -19, 20-39, 40-59, 60-79, and 80- years. RESULTS: Most patients under 19 had mild COVID-19 on admission (99%), while older patients had more severe COVID-19. The incidence rates of clinical outcomes during hospitalization in patients aged ≤ 19, 20-39, 40-59, 60-79, and 80 ≥ years were 0.0%, 0.5%, 2.2%, 2.7%, and 1.5% for thrombosis; 0.0%, 1.2%, 1.5%, 3.4%, and 2.0% for major bleeding; and 0.0%, 0.4%, 2.0%, 12.1%, and 16.8% for all-cause death, respectively. In the stratified analysis according to COVID-19 severity on admission, the incidences of thrombosis were generally higher among patients with more severe status, although those were not significantly different among age strata in all sub-types of COVID-19 severity. However, the incidences of all-cause death were significantly higher with increasing age in all sub-types of COVID-19 severity. CONCLUSIONS: In the current large observational study of patients with COVID-19, the risk of mortality became markedly higher with increased age. However, the risks of thrombosis and major bleeding did not necessarily increase as age increases, which seemed to be consistent irrespective of COVID-19 severity on admission.

Risk Factors and Impact on Outcomes of Thrombosis in Patients with COVID-19 in Japan: From the CLOT-COVID Study.

Objectives: The relationship between the thrombotic event and prognosis in patients with coronavirus disease 2019 (COVID-19) has not yet been fully investigated in Japan. Our study aimed to investigate the clinical outcomes and risk factors for thrombosis in hospitalized patients with COVID-19 in Japan. Materials and Methods: We compared the patient characteristics and clinical outcomes among patients with thrombosis (N=55) and those without thrombosis (N=2839) by using a large-scale data of CLOT-COVID study (thrombosis and antiCoaguLatiOn Therapy in patients with COVID-19 in Japan Study: UMIN000045800). Thrombosis included venous thromboembolism, ischemic stroke, myocardial infarction, and systemic arterial thromboembolism. Results: Higher rates of mortality and bleeding events were shown in hospitalized patients with COVID-19 with thrombosis compared to those without thrombosis (all-cause mortality, 23.6% vs. 5.1%, P<0.001; major bleeding, 23.6% vs. 1.6%, P<0.001). Multivariable analysis revealed that the independent risk factors of thrombosis were male sex, D-dimer level on admission>1.0 µg/mL, and moderate and severe COVID-19 status on admission. Conclusions: The development of thrombosis in hospitalized patients with COVID-19 was related to higher mortality and major bleeding, and several independent risk factors for thrombosis could help determine the patient-appropriate treatment for COVID-19.

Clinical Features Comparing Arterial Thrombosis and Venous Thromboembolism in Hospitalized Patients with COVID-19: Result from the CLOT-COVID Study.

Objectives: This study aimed to investigate the clinical features of arterial thrombosis and venous thromboembolism (VTE) in coronavirus disease 2019 (COVID-19). Methods: The CLOT-COVID Study was a retrospective, multicenter cohort study that enrolled 2,894 consecutively hospitalized patients with COVID-19 among 16 centers in Japan from April 2021 to September 2021. We compared the clinical features of arterial thrombosis and VTE. Results: Thrombosis was observed in 55 patients (1.9%) during hospitalization. Arterial thrombosis and VTE occurred in 12 (0.4%) and 36 (1.2%) patients, respectively. Among the 12 patients with arterial thrombosis, 9 (75%), 2 (17%), and 1 developed ischemic cerebral infarction, myocardial infarction, and acute limb ischemia, respectively, and there were five patients (42%) without comorbidities. Among 36 patients with VTE, 19 (53%) and 17 (47%) developed pulmonary embolism (PE) and deep vein thrombosis (DVT), respectively. PE was common in the early stages of hospitalization; whereas, DVT was common beyond the early stages of hospitalization. Conclusion: Among patients with COVID-19, arterial thrombosis was less common than VTE, although ischemic cerebral infarction seemed to be relatively common, and a certain number of patients developed arterial thrombosis even in the absence of known atherosclerosis risk factors.

Diagnostic criteria for Buerger's disease: International Consensus of VAS - European Independent Foundation in Angiology/Vascular Medicine.

Buerger's disease (BD) remains a debilitating condition and early diagnosis is paramount for its effective management. Despite many published diagnostic criteria for BD, selective criteria have been utilized in different vascular centers to manage patients with BD worldwide. A recent international Delphi Consensus Study on the diagnostic criteria of BD showed that none of these published diagnostic criteria have been universally accepted as a gold standard. Apart from the presence of smoking, these published diagnostic criteria have distinct differences between them, rendering the direct comparison of patient outcomes difficult. Hence, the expert committees from the Working Group of the VAS-European Independent Foundation in Angiology/Vascular Medicine critically reviewed the findings from the Delphi study and provided practical recommendations on the diagnostic criteria for BD, facilitating its universal use. We recommend that the 'definitive' diagnosis of BD must require the presence of three features (history of smoking, typical angiographic features and typical histopathological features) and the use of a combination of major and minor criteria for the 'suspected' diagnosis of BD. The major criterion is the history of active tobacco smoking. The five minor criteria are disease onset at age less than 45 years, ischemic involvement of the lower limbs, ischemic involvement of one or both of the upper limbs, thrombophlebitis migrans and red-blue shade of purple discoloration on edematous toes or fingers. We recommend that a 'suspected' diagnosis of BD is confirmed in the presence of a major criterion plus four or more minor criteria. In the absence of the major criterion or in cases of fewer than four minor criteria, imaging and laboratory data could facilitate the diagnosis. Validation studies on the use of these major and minor criteria are underway.

Buerger Disease: Pathological Changes in Elderly Patients.

Reports of vascular lesion changes in elderly Buerger disease patients are rare. Patients are expected to continue to have typical Buerger disease even after the age of 50. However, after 50, when patients suffer from atherosclerotic risk factors, such as hypertension, diabetes mellitus, or hyperlipidemia, what kind of changes will occur? We will report on 3 cases of hypertension, diabetes mellitus, or hyper lipidemia after or around 50 years of age. As a result, atherosclerosis was present in the iliac or aortic regions in the remaining thromboangiitis lesions below the groin area. (This is secondary publication from the J Jpn Coll Angiol 2021; 61: 107-113.).

D-Dimer Values and Venous Thromboembolism in Patients With COVID-19 in Japan　- From the CLOT-COVID Study.

Background: To date, there are no large-scale data on the association between D-dimer levels at admission and the occurrence of venous thromboembolism (VTE) in Japanese patients with coronavirus disease 2019 (COVID-19). Methods and Results: The CLOT-COVID study was a retrospective, multicenter cohort study enrolling consecutive hospitalized patients with COVID-19 across 16 centers in Japan from April 2021 to September 2021. Among 2,894 enrolled patients, 2,771 (96%) had D-dimer levels measured at admission. Patients were divided into 3 groups based on tertiles of D-dimer levels at admission (1st tertile, D-dimer ≤0.5 µg/mL, n=949; 2nd tertile, D-dimer 0.51-1.09 µg/mL, n=894; 3rd tertile, D-dimer ≥1.1 µg/mL, n=928). The higher the tertile group, the more severe the COVID-19 status at admission. The incidence of VTE during hospitalization was highest in the 3rd tertile group (1st tertile, 0.3%; 2nd tertile, 0.3%; 3rd tertile, 3.6%; P<0.001). Even after adjusting for confounders in the multivariable logistic regression model, the higher D-dimer levels in the 3rd tertile (≥1.1 µg/mL) were independently associated with a higher risk of VTE during hospitalization (adjusted odds ratio 4.83 [95% confidence interval 1.93-12.11; P<0.001]; reference=1st tertile). Conclusions: Higher D-dimer levels at admission were associated with a higher risk of VTE events during hospitalization in Japanese patients with COVID-19. This could be helpful in determining patient-specific anticoagulation management strategies for COVID-19 in Japan.

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.

Influence of sex on development of thrombosis in patients with COVID-19: From the CLOT-COVID study.

INTRODUCTION: There has been limited data on the influence of sex on development of thrombosis in patients with coronavirus disease 2019 (COVID-19). MATERIALS AND METHODS: The CLOT-COVID Study was a retrospective, multicenter cohort study enrolling 2894 consecutive hospitalized patients with COVID-19 among 16 centers in Japan from April 2021 to September 2021. We divided the entire cohort into the men (N = 1885) and women (N = 1009) groups. RESULTS: There were no significant differences in D-dimer levels at admission between men and women. Men had more severe status of the COVID-19 at admission compared with women (Mild: 57% versus 66%, Moderate: 34% versus 29%, and Severe: 9.1% versus 5.7%, P < 0.001). Men more often received pharmacological thromboprophylaxis than women (47% versus 35%, P < 0.001). During the hospitalization, men more often developed thrombosis than women (2.5% [95%CI, 1.9-3.3%] versus 0.8% [95%CI, 0.4-1.6%], P = 0.001). Men had numerically higher incidences of thrombosis than women in all subgroups of the worst severity of COVID-19 during the hospitalization (Mild: 0.3% versus 0.0%, Moderate: 1.6% versus 1.0%, and Severe: 11.1% versus 4.3%). Even after adjusting confounders in the multivariable logistic regression model, the excess risk of men relative to women remained significant for thrombosis (adjusted OR, 2.51; 95%CI, 1.16-5.43, P = 0.02). CONCLUSIONS: In the current large observational study of patients with COVID-19, men had more severe status of the COVID-19 than women, and the risk of development of thrombosis was higher in men compared with women, which could be helpful in determining the patient-specific optimal management strategies for COVID-19.

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 single nucleotide polymorphism in the 3'-untranslated region of MyD88 gene is associated with Buerger disease but not with Takayasu arteritis in Japanese.

Buerger disease (BD) and Takayasu arteritis (TA) are rare vascular disorders. Although their etiology and pathogenesis have not been elucidated, several studies have suggested the involvement of innate immunity. Myeloid differentiation primary-response protein 88 (MyD88) is a key signaling adaptor for all Toll-like receptors, which have a central role in innate immunity. In the present study, we evaluated the association of MyD88 with BD and TA. We conducted case-control studies in Japanese populations composing of 131 BD cases, 90 TA cases and 270 healthy controls to be genotyped for a single nucleotide polymorphism rs7744 A>G in the 3'-untranslated region of MyD88 gene. The frequency of GG genotype was significantly lower in the BD patients than in the controls (6.9 vs 15.9%, P=0.011, odds ratio=0.39, 95% confidence interval; 0.19, 0.81), although there was no significant difference in the genotype frequencies between the TA patients and controls. It was suggested that MyD88 may confer resistance to BD in Japanese. Because this is the first report of the association between MyD88 and BD, replication studies in other cohorts are required.