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.

Outcomes of patients with cerebral microbleeds undergoing percutaneous coronary intervention and dual antiplatelet therapy.

INTRODUCTION: Cerebral microbleeds (CMBs) on brain magnetic resonance imaging (MRI) are predictive of intracerebral hemorrhage (ICH). However, the risk of ICH in patients with CMBs who undergo percutaneous coronary intervention (PCI) while receiving dual antiplatelet therapy (DAPT) is unclear. MATERIALS AND METHODS: We conducted a study on 329 consecutive patients with coronary artery disease who underwent PCI and were evaluated using a 3T MRI scanner. Based on T2*-weighted imaging, patients were classified into three groups: no CMBs, < 5 CMBs, or ≥ 5 CMBs. We determined the occurrence of ICH during follow-up. RESULTS: At least 1 CMB was found in 109 (33%) patients. The mean number of CMBs per patient was 2.9 ± 3.6. Among the 109 patients with CMBs, 16 (15%) had ≥ 5 CMBs. Coronary stent implantation was performed in 321 patients (98%). DAPT was prescribed for 325 patients (99%). During a mean follow-up period of 2.3 years (interquartile range, 1.9-2.5 years), ICH occurred in one patient (1.1%) with four CMBs. There were no significant differences in the incidence of ICH (0% vs. 1.1% vs. 0%; p = 0.28). However, the rate of DAPT at 6 months of follow-up was significantly lower in patients with ≥ 5 CMBs than in patients with no CMBs or < 5 CMBs (89% vs. 91% vs. 66%, p = 0.026). Furthermore, there were no significant differences in systemic blood pressure during follow-up (123 ± 16 vs. 125 ± 16 vs. 118 ± 11 mmHg; p = 0.40). CONCLUSION: Although a substantial number of patients who underwent PCI had cerebral microbleeds, at approximately two years of follow-up, intracerebral hemorrhage was very rare in our study population.

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.

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.

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.

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.

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.

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.

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.

Prevalence of carotid artery stenosis with coronary artery disease in Japanese patients: A single-center study.

There are a few reports of the prevalence of extracranial internal carotid artery stenosis (ICAS) in Asian patients with coronary artery disease (CAD). This was a prospective registry study of 157 consecutive Japanese patients undergoing coronary angiography that aimed to determine the prevalence of extracranial ICAS in recent Japanese patients. The associations between ICAS and the extent or the maximal stenosis of CAD were also investigated. The 131 eligible patients with suspected CAD were prospectively analyzed. Their mean age was 69.0 ± 8.2 years, and 75.6% were males. A total of 111 patients (84.7%) were angiographically diagnosed with CAD. ICAS (area stenosis ≥50% on ultrasonography) was present in 9 patients, and the prevalence in patients with CAD was 8.1%. All patients in the ICAS group had CAD, and this group was significantly more likely to have a history of stroke (p = 0.03). Although no significant relationships were found between the severity of ICAS and the maximal stenosis of CAD, the severity of ICAS increased gradually with the extent of CAD. The prevalence of ICAS in patients with CAD treated with current medical treatment was relatively low (8.1%) compared to previous reports, and the severity of ICAS was significantly associated with the extent of CAD.

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.

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.

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.

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.

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.

Selective Synthesis of the Aminobutadiene Intermediate and Mechanistic Analysis of 1,4-Dihydropyridine Formation Reaction in Water.

We previously isolated an aminobutadiene derivative as a by-product in the synthesis of a 1,4-dihydropyridine (1,4-DHP) derivative by the reaction of methyl propiolate with excess ammonium acetate in water, and we proposed that it is an intermediate in the formation of 1,4-DHP. Here, to test this idea and to investigate the reaction mechanism, we selectively synthesized the aminobutadiene derivative in EtOH and examined its reactivity. The yield of the aminobutadiene derivative was increased in the presence of excess ammonium salt. X-Ray crystal structure analysis indicated the presence of an intramolecular hydrogen bond between the terminal amine and ester carbonyl oxygen, together with a short C-N bond length consistent with enamine-imine equilibrium. Direct cyclization of the aminobutadiene derivative with methyl propiolate to afford the 1,4-DHP derivative did not proceed well, but the yield was increased in the presence of morpholine salt as an additive. These results suggest that the predominant reaction pathway from the intermediate to 1,4-DHP in water involves Michael addition of a second amine molecule and reaction with methyl propiolate, followed by intramolecular cyclization and elimination of amine.

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.

DNA-cleavage activity of the iron(II) complex with optically active ligands, meta- and para-xylyl-linked N',N'-dipyridylmethyl-cyclohexane-1,2-diamine.

DNA-cleavage agents such as bleomycin have potential anticancer applications. The development of a DNA-cleavage reagent that recognizes specific sequences allows the development of cancer therapy with reduced side effects. In this study, to develop novel compounds with specific DNA-cleavage activities, we synthesized optically active binuclear ligands, (1R,1'R,2R,2'R)-N1,N1'-(meta/para-phenylenebis(methylene))bis(N2,N2-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine) and their enantiomers. The DNA-cleavage activities of these compounds were investigated in the presence of Fe(II)SO4 and sodium ascorbate. The obtained results indicated that the Fe(II) complexes of those compounds efficiently cleave DNA and that their cleavage was subtle sequence-selective. Therefore, we succeeded in developing compounds that can be used as small-molecule drugs for cancer chemotherapy.

Design and synthesis of an anthranyl bridged optically active dinuclear iron(II)-ligand and evaluation of DNA-cleaving activity.

It is necessary to design a ligand that is compatible with the target molecule to optimally use the DNA-cleaving ability of metal complexes. In this study, we synthesized an optically active dinuclear ligand, (1R,1'R,2R,2'R)-N1,N1'-(anthracene-1,8-diylbis(methylene))bis(N2,N2-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine) (R-ABDC, 4a) and its enantiomer (S-ABDC, 4b). We then prepared their Fe(II) complexes by mixing the ligand with FeSO4·7H2O in situ and investigated DNA-cleaving activities using plasmid DNA in the presence of excess sodium ascorbate at atmospheric conditions. The Fe(II) complexes efficiently cleaved DNA and selectively recognized two consecutive A and/or T sequences.