Impact of glycated hemoglobin on 2-year clinical outcomes in elderly patients with atrial fibrillation: sub-analysis of ANAFIE Registry, a large observational study.

BACKGROUND: This ANAFIE Registry sub-analysis investigated 2-year outcomes and oral anticoagulant (OAC) use stratified by glycated hemoglobin (HbA1c) levels among Japanese patients aged ≥ 75 years with non-valvular atrial fibrillation (NVAF) with and without clinical diagnosis of diabetes mellitus (DM). METHODS: The ANAFIE Registry was a large-scale multicenter, observational study conducted in Japan; this sub-analysis included patients with baseline HbA1c data at baseline. The main endpoints evaluated (stroke/systemic embolic events [SEE], major bleeding, intracranial hemorrhage, cardiovascular death, all-cause death, and net clinical outcome [a composite of stroke/SEE, major bleeding, and all-cause death]) were stratified by HbA1c levels (< 6.0%; 6.0% to < 7.0%; 7.0% to < 8.0%; and ≥ 8.0%). RESULTS: Of 17,526 patients with baseline HbA1c values, 8725 (49.8%) patients had HbA1c < 6.0%, 6700 (38.2%) had 6.0% to < 7.0%, 1548 (8.8%) had 7.0% to < 8.0%, and 553 (3.2%) had ≥ 8.0%. Compared with other subgroups, patients with HbA1c ≥ 8.0% were more likely to have lower renal function, higher CHA2DS2-VASc and HAS-BLED scores, higher prevalence of non-paroxysmal AF, and lower direct OAC (DOAC) administration, but higher warfarin administration. The HbA1c ≥ 8.0% subgroup had higher event rates for all-cause death (log-rank P = 0.003) and net clinical outcome (log-rank P = 0.007). Similar trends were observed for stroke/SEE. In multivariate analysis, risk of all-cause death (adjusted hazard ratio [aHR]: 1.46 [95% confidence interval 1.11-1.93]) and net clinical outcome (aHR 1.33 [1.05-1.68]) were significantly higher in the HbA1c ≥ 8.0% subgroup. No significant differences were observed in risks of major bleeding or other outcomes in this and other subgroups. No interaction was observed between HbA1c and OACs. Use/non-use of antidiabetic drugs was not associated with risk reduction; event risks did not differ with/without injectable antidiabetic drugs. CONCLUSIONS: Among elderly Japanese patients with NVAF, only HbA1c ≥ 8.0% was associated with increased all-cause death and net clinical outcome risks; risks of the events did not increase in other HbA1c subgroups. Relative event risks between patients treated with DOACs and warfarin were not modified by HbA1c level. TRIAL REGISTRATION: UMIN000024006; date of registration: September 12, 2016.

Relationship Between Direct Oral Anticoagulant Doses and Clinical Outcomes in Elderly Patients With Non-Valvular Atrial Fibrillation　- ANAFIE Registry Sub-Analysis.

BACKGROUND: This sub-analysis of the ANAFIE Registry, a prospective, observational study of >30,000 Japanese non-valvular atrial fibrillation (NVAF) patients aged ≥75 years, assessed the prevalence of direct oral anticoagulant (DOAC) under-dose prevalence, identified the factors of under-dose prescriptions, and examined the relationship between DOAC dose and clinical outcomes.Methods and Results: Patients, divided into 5 groups by DOAC dose (standard, over-, reduced, under-, and off-label), were analyzed for background factors, cumulative incidences, and clinical outcome risk. Endpoints were stroke/systemic embolic events (SEE), major bleeding, and all-cause death during the 2-year follow-up. Of 18,497 patients taking DOACs, 20.7%, 3.8%, 51.6%, 19.6%, and 4.3%, were prescribed standard, over-, reduced, under-, and off-label doses. Factors associated with under-dose use were female sex, age ≥85 years, reduced creatinine clearance, history of major bleeding, polypharmacy, antiplatelet agents, heart failure, dementia, and no history of catheter ablation or cerebrovascular disease. After confounder adjustment, under-dose vs. standard dose was not associated with the incidence of stroke/SEE or major bleeding but was associated with a higher mortality rate. Patients receiving an off-label dose showed similar tendencies to those receiving an under-dose; that is, they showed the highest mortality rates for stroke/SEE, major bleeding, and all-cause death. CONCLUSIONS: Inappropriate low DOAC doses (under- or off-label dose) were not associated with stroke/SEE or major bleeding but were associated with all-cause death.

Causes of Death in Elderly Patients With Non-Valvular Atrial Fibrillation　- Results From the ANAFIE Registry.

BACKGROUND: Previous studies on mortality in atrial fibrillation (AF) included a limited number of elderly patients receiving direct oral anticoagulants (DOACs). This subanalysis of the ANAFIE Registry evaluated 2-year mortality according to causes of death of elderly non-valvular AF (NVAF) patients in the DOAC era.Methods and Results: The ANAFIE Registry was a multicenter prospective observational study. Mean patient age was 81.5 years and 57.3% of patients were male. Of the 32,275 patients completing the study, 2,242 died. The most frequent causes of death were cardiovascular (CV) death (32.4%), followed by infection (17.1%) and malignancy (16.1%). Incidence rates of CV-, malignancy-, and infection-related death were 1.20, 0.60, and 0.63 per 100 person-years, respectively. Patients aged ≥85 years showed increased proportions of non-CV and non-malignancy deaths and a decreased proportion of malignancy deaths compared with patients aged <85 years. The incidence of death due to congestive heart failure/cardiogenic shock, infection, and renal disease was higher in patients aged ≥85 than those aged <85 years. Compared with warfarin, DOACs were associated with a significantly lower risk of death by intracranial hemorrhage, ischemic stroke, and renal disease. CONCLUSIONS: This subanalysis described the mortality according to causes of death of Japanese elderly NVAF patients in the DOAC era. Our results imply that a more holistic approach to comorbid conditions and stroke prevention are required in these patients.

Echocardiographic Parameters of Left Atrial Structure and Function and Clinical Outcomes at 2 Years in Elderly Patients With Atrial Fibrillation　- The ANAFIE Echocardiographic Substudy.

BACKGROUND: This prospective ANAFIE Registry substudy investigated the relationship between the echocardiographic parameters of left atrial (LA) structure and function and clinical outcomes at 2 years among atrial fibrillation (AF) patients aged ≥75 years.Methods and Results: Outcomes of 1,474 elderly non-valvular AF (NVAF) patients who underwent transthoracic echocardiography at baseline were analyzed by categories of maximum LA volume index (max. LAVi) and LA emptying fraction (LAEF) total. Baseline mean±standard deviation LAEF total and max. LAVi were 28.2±14.9% and 54.2±25.9 mL/m2, respectively. Proportions of oral anticoagulant (OAC), direct OAC, and warfarin use were 92.7%, 68.7%, and 24.0%, respectively. Patients with LAEF total ≤45.0% (n=1,213) vs. >45.0% (n=224) were at higher risk of cardiovascular events (hazard ratio [HR]: 2.19, P=0.021) and heart failure (HF) hospitalization (HR: 2.25, P=0.045). Risk of all-cause death was higher with max. LAVi >48.0 mL/m2(n=656) vs. ≤48.0 mL/m2(n=621) (HR: 1.69, P=0.048). Subgroups with abnormal LA function and structure had increased incidence of cardiac/cardiovascular events and HF hospitalization. No significant interaction was observed between echocardiographic parameters and OAC type. CONCLUSIONS: Elderly Japanese patients with NVAF and LAEF total ≤45.0% were at higher risk of cardiovascular events and HF hospitalization, and those with max. LAVi >48.0 mL/m2were at higher risk of all-cause death.

Impact of Previous Stroke on Clinical Outcome in Elderly Patients With Nonvalvular Atrial Fibrillation: ANAFIE Registry.

BACKGROUND: We determined the long-term event incidence among elderly patients with nonvalvular atrial fibrillation in terms of history of stroke/transient ischemic attack (TIA) and oral anticoagulation. METHODS: Patients aged ≥75 years with documented nonvalvular atrial fibrillation enrolled in the prospective, multicenter, observational All Nippon Atrial Fibrillation in the Elderly Registry between October 2016 and January 2018 were divided into 2 groups according to history of stroke/TIA. The primary end point was the occurrence of stroke/systemic embolism within 2 years, and secondary end points were major bleeding and all-cause death within 2 years. Cox models were used to determine whether there was a difference in the hazard of each end point in patients with/without history of stroke/TIA, and in ischemic stroke/TIA survivors taking direct oral anticoagulants versus those taking warfarin. RESULTS: Of 32 275 evaluable patients (13 793 women [42.7%]; median age, 81.0 years), 7304 (22.6%) had a history of stroke/TIA. The patients with previous stroke/TIA were more likely to be male and older and had higher hazard rates of stroke/systemic embolism (adjusted hazard ratio, 2.25 [95% CI, 1.97-2.58]), major bleeding (1.25, 1.05-1.49), and all-cause death (1.13, 1.02-1.24) than the other groups. Of 6446 patients with prior ischemic stroke/TIA, 4393 (68.2%) were taking direct oral anticoagulants and 1668 (25.9%) were taking warfarin at enrollment. The risk of stroke/systemic embolism was comparable between these 2 groups (adjusted hazard ratio, 0.90 [95% CI, 0.71-1.14]), while the risk of major bleeding (0.67, 0.48-0.94), intracranial hemorrhage (0.57, 0.39-0.85), and cardiovascular death (0.71, 0.51-0.99) was lower among those taking direct oral anticoagulants. CONCLUSIONS: Patients aged ≥75 years with nonvalvular atrial fibrillation and previous stroke/TIA more commonly had subsequent ischemic and hemorrhagic events than those without previous stroke/TIA. Among patients with previous ischemic stroke/TIA, the risk of hemorrhagic events was lower in patients taking direct oral anticoagulants compared with warfarin. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique Identifier: UMIN000024006.

Effect of Polypharmacy on Clinical Outcomes in Elderly Patients With Non-Valvular Atrial Fibrillation　- A Sub-Analysis of the ANAFIE Registry.

BACKGROUND: This All Nippon AF in the Elderly (ANAFIE) Registry sub-analysis evaluated the impact of polypharmacy on 2-year outcomes in a large, elderly (aged ≥75 years) Japanese population with non-valvular atrial fibrillation (NVAF).Methods and Results: The ANAFIE Registry was a multicenter, prospective, observational study with a 24-month follow-up period. Of 32,275 enrolled NVAF patients, 31,419 were grouped by the number of prescribed concomitant medications (other than oral anticoagulants [OACs]): 0-4 [38.8%], 5-8 [43.3%], and ≥9 [17.9%]). Patients receiving more concomitant medications were older, had poor renal function, and suffered more comorbidities than those receiving fewer concomitant medications. Several patient background factors, including diabetes mellitus, myocardial infarction, and chronic kidney disease, were significantly correlated with an increased number of concomitant medications. With increasing medications, OAC prescription rates decreased, but the warfarin prescription rate increased, and the cumulative incidence rates of stroke/systemic embolic events (SEE), major bleeding, gastrointestinal bleeding, fracture/falls, cardiovascular events, cardiovascular death, and all-cause death significantly increased (each, P<0.05). In multivariate analysis, increasing medications was independently associated with increases in these events, except for stroke/SEE. There were no significant interactions between the number of medications and anticoagulant treatment with direct OAC or warfarin concerning the incidence of these events. CONCLUSIONS: Polypharmacy was frequent among elderly patients with NVAF who were older with more comorbidities, and was independently associated with a higher incidence of extracranial events.

Edoxaban, a direct oral factor Xa inhibitor, ameliorates coagulation, microvascular thrombus formation, and acute liver injury in a lipopolysaccharide-induced coagulopathy model in rats.

Infection increases the risk of thrombosis through the activation of inflammation and coagulation. Edoxaban, a direct oral factor Xa inhibitor, is used for the prevention and treatment of thrombotic diseases. The aim of this study was to determine the effects of edoxaban on microvascular thrombus formation in a rat model of lipopolysaccharide (LPS)-induced coagulopathy. Rats were intravenously injected with 7.5 mg/kg of LPS (Escherichia coli 055:B5). Immediately after LPS injection, the rats were treated with subcutaneous injection of edoxaban. At 2 and 6 h after the injection of LPS, biomarkers of coagulation and organ damages and inflammatory cytokines were measured. Microvascular thrombus formation in organs was evaluated using 125I-fibrinogen (human) or by the pathological analysis. Mortality was examined 24 h after LPS injection. After the injection of LPS, D-dimer and thrombin-antithrombin complex increased and platelet numbers decreased, indicating the activation of coagulation. Microvascular thrombi were found in the liver. Markers of liver injury (aspartate aminotransferase and alanine aminotransferase) also increased. Treatment with edoxaban attenuated the changes in the coagulation markers and microvascular thrombus formation in the liver. Edoxaban suppressed the increase in the liver injury markers and reduced the mortality. Edoxaban did not affect the levels of inflammatory cytokines. In conclusions, edoxaban significantly inhibited the activation of coagulation, the formation of microvascular thrombus in the liver and the liver damage, and reduced mortality in rats injected with LPS. These results suggest that the FXa inhibition by edoxaban might be a beneficial therapy for the management of infection-associated thrombosis.

Effects of concomitant use of prasugrel with edoxaban on bleeding time, pharmacodynamics, and pharmacokinetics of edoxaban in healthy elderly Japanese male subjects: a clinical pharmacology study.

BACKGROUND: Dual therapy with a direct oral anticoagulant (DOAC) plus a P2Y12 receptor inhibitor is recommended in patients with nonvalvular atrial fibrillation who undergo percutaneous coronary intervention. Thus, we evaluated the effects of DOAC edoxaban plus P2Y12 receptor inhibitor prasugrel on bleeding time (BT), and pharmacodynamics (PD) and pharmacokinetics (PK) of edoxaban in healthy elderly Japanese male subjects. METHODS: A single-center, clinical pharmacology study with randomized, open-label, repeated dosing enrolled 24 participants in two groups of 12 receiving 30 mg edoxaban once daily for 3 days; then 30 mg edoxaban plus 2.5 mg prasugrel (Group 1) or 30 mg edoxaban plus 3.75 mg prasugrel (Group 2) once daily for 5 days. Primary endpoint was BT by the Ivy method. Secondary endpoints were the PD parameters of prothrombin time (PT), activated partial thromboplastin time (aPTT), prothrombin fragment F1 + 2 (F1 + 2), and P2Y12 reaction units (PRU), and PK profiles of edoxaban alone and in combination with prasugrel. RESULTS: Geometric least squares mean of BT ratios (vs. baseline) for 3-day edoxaban treatment were 1.097 (90% confidence interval (CI) 0.911-1.321) in Group 1 and 1.327 (90% CI 1.035-1.703) in Group 2; for 5-day edoxaban plus 2.5 mg and 3.75 mg prasugrel, they were 1.581 (90% CI 1.197-2.087) and 1.996 (90% CI 1.482-2.690), respectively. Contributions of prasugrel to the effects (edoxaban + prasugrel/edoxaban) were 1.442 (90% CI 1.096-1.897) in Group 1 and 1.504 (90% CI 1.172-1.930) in Group 2. Edoxaban prolonged PT and aPTT and decreased F1 + 2. Adding on prasugrel did not appreciably change PT, aPTT, or F1 + 2. Prasugrel reduced PRU, whereas edoxaban had no effect on PRU. We recorded 26 adverse events; 23 were treatment-emergent (positive fecal occult blood test). All participants with adverse events recovered during follow-up. CONCLUSIONS: Coadministration of 2.5 mg and 3.75 mg prasugrel with 30 mg edoxaban prolonged BT in healthy elderly Japanese male subjects. The effect was dependent on the dose of prasugrel. Prasugrel did not affect PD or PK profiles of edoxaban. Edoxaban had no effect on PD of prasugrel. TRIAL REGISTRATION: Japan Registry of Clinical Trials No. jRCTs071190006; registration date, 26-April-2019.

Combined effect of a direct oral anticoagulant edoxaban and an inhibitor of activated thrombin-activatable fibrinolysis inhibitor on clot lysis.

Fibrinolysis is regulated by the thrombin/thrombin-activatable fibrinolysis inhibitor (TAFI) system. Thus, anticoagulants and inhibitors of TAFI are expected to accelerate fibrinolysis. The combined effects of an anticoagulant and a TAFIa inhibitor on fibrinolysis remain unknown. The aim of this study was to evaluate the combined effect of edoxaban, an oral direct factor Xa (FXa) inhibitor, and a TAFIa inhibitor, potato tuber carboxypeptidase inhibitor (PCI) on tissue-type plasminogen activator (t-PA)-induced clot lysis in human plasma in vitro. Pooled human plasma (containing 180 ng/mL t-PA and 0.1 nM thrombomodulin) was mixed with edoxaban and/or PCI. Clot formation was induced by 2.5 pM tissue factor and 4 µM phospholipids and clot lysis time was examined. Plasma plasmin-α2 antiplasmin complex (PAP) concentration was measured as a marker of plasmin generation. Edoxaban or PCI alone significantly shortened the t-PA-induced clot lysis time and plasma PAP concentration. The combination of these compounds significantly accelerated the clot lysis compared with the inhibitors alone. Addition of PCI (0.3, 1, and 3 µg/mL) to 75 ng/mL edoxaban increased plasma PAP concentration compared with edoxaban alone; however, compared with PCI alone only the combination of 0.3 µg/mL PCI + 75 ng/mL edoxaban showed the significant increase in PAP concentration. Concomitant use of an oral direct FXa inhibitor, edoxaban, and a TAFIa inhibitor, PCI, significantly accelerate fibrinolysis via enhancement of plasmin generation. These results suggest that the combination of edoxaban and a TAFIa inhibitor might be beneficial for the treatment of thromboembolic diseases.

Association between plasma concentration of edoxaban determined by direct and indirect methods in Japanese patients with non-valvular atrial fibrillation (CVI ARO 7).

Direct oral anticoagulants, including edoxaban, primarily do not need routine monitoring of the anticoagulant effect. However, extremely high/low plasma concentrations of edoxaban (PC-Ed) should be properly evaluated, especially when patients under anticoagulation therapy are at an emergency state. For this purpose, PC-Ed determined by an anti-Xa assay (indirect PC-Ed) is more convenient and, therefore, more useful compared with PC-Ed determined by an LC-MS/MS (direct PC-Ed) in daily clinical practice. Consecutive 97 patients with non-valvular atrial fibrillation (NVAF) under edoxaban therapy were evaluated, in whom edoxaban 60/30 mg doses were prescribed for 48/49 patients, 71 (73.2%) were men, and the average age was 69 years. CHADS2 score 0, 1, and ≥ 2 were 26.8%, 44.3%, and 28.9%, while CHA2DS2-VASc score 0, 1, and ≥ 2 were 14.4%, 16.5%, and 69.1%, respectively. Median values of direct and indirect PC-Ed by LC-MS/MS and anti-Xa assay were 187.1 and 176.1 ng/mL at peak (2-4 h post-dose) and 14.4 and 17.5 ng/mL at trough (pre-dose), respectively. The PC-Ed at peak and trough by two methods were significantly correlated, and the correlation coefficients were r = 0.973 and 0.963 (both, p < 0.0001), respectively. By a Bland-Altman plot, mean differences between the direct and indirect PC-Ed [lower to upper percent limit of agreement] were - 4.87 [- 46.71 to 36.98] and 4.66 [- 1.37 to 10.69] ng/mL at peak and trough, respectively. Moreover, mean % error for difference between the direct and indirect PC-Ed [lower to upper percent limit of agreement] was - 1.22 [- 20.59 to 18.14] and 31.75 [- 14.03 to 77.53] % at peak and trough, respectively, where the % error extremely increased around the lower limit of detection (LLOD) in the anti-Xa assay. Strong similarity was observed between the direct and indirect PC-Ed, especially at peak. The indirect PC-Ed was higher than the direct PC-Ed, especially around the LLOD, suggesting the need for caution when we use the anti-Xa assay for measurement of trough PC-Ed (UMIN 000032492).

Exploratory Analysis of Circulating miRNA Signatures in Atrial Fibrillation Patients Determining Potential Biomarkers to Support Decision-Making in Anticoagulation and Catheter Ablation.

Novel biomarkers are desired to improve risk management for patients with atrial fibrillation (AF). We measured 179 plasma miRNAs in 83 AF patients using multiplex qRT-PCR. Plasma levels of eight (i.e., hsa-miR-22-3p, hsa-miR-128-3p, hsa-miR-130a-3p, hsa-miR-140-5p, hsa-miR-143-3p, hsa-miR-148b-3p, hsa-miR-497-5p, hsa-miR-652-3p) and three (i.e., hsa-miR-144-5p, hsa-miR-192-5p, hsa-miR-194-5p) miRNAs showed positive and negative correlations with CHA2DS2-VASc scores, respectively, which also showed negative and positive correlations with catheter ablation (CA) procedure, respectively, within the follow-up observation period up to 6-month after enrollment. These 11 miRNAs were functionally associated with TGF-ß signaling and androgen signaling based on pathway enrichment analysis. Seven of possible target genes of these miRNAs, namely TGFBR1, PDGFRA, ZEB1, IGFR1, BCL2, MAPK1 and DICER1 were found to be modulated by more than four miRNAs of the eleven. Of them, TGFBR1, PDGFRA, ZEB1 and BCL2 are reported to exert pro-fibrotic functions, suggesting that dysregulations of these eleven miRNAs may reflect pro-fibrotic condition in the high-risk patients. Although highly speculative, these miRNAs may potentially serve as potential biomarkers, providing mechanistic and quantitative information for pathophysiology in daily clinical practice with AF such as possible pro-fibrotic state in left atrium, which would enhance the risk of stroke and reduce the preference for performing CA.

Sensory evaluation of edoxaban orally disintegrating tablets: an open-label interventional study (secondary publication).

BACKGROUND: This study involved a sensory evaluation of edoxaban orally disintegrating (OD) tablets in patients with nonvalvular atrial fibrillation who had been receiving the existing edoxaban film-coated tablets before the study. METHODS: Edoxaban OD tablets 30 or 60 mg were prescribed for patients who had been receiving the existing 30- or 60-mg edoxaban film-coated tablets before the study. Each dose group was randomized into groups taking the tablets with or without water. After ingestion of the edoxaban OD tablet, each patient was asked to complete a sensory evaluation questionnaire (12 items). RESULTS: In the evaluation of satisfaction with edoxaban OD tablets, 52.8% of the patients perceived "no difference" from the existing edoxaban film-coated tablets and 34.9% indicated that they were more satisfied with the OD tablets, thus demonstrating a relatively high degree of satisfaction. When asked about convenience and reliability in using edoxaban OD tablets, about half of the patients perceived "no difference" from the existing edoxaban film-coated tablets and the remaining half indicated preference for the OD tablets. Responses about taste, flavor, ease of ingestion, and motivation to continue taking edoxaban indicated the overall acceptance of the OD tablets. Recognition of edoxaban OD tablets was rated as "easy" by about half of the patients and "difficult" by the remaining half. Among all patients, 49.5% preferred a change to edoxaban OD tablets. The degree of satisfaction with taste, flavor, and ease of ingestion, as well as overall satisfaction, tended to be greater when the OD tablets were taken with rather than without water, and the percentage of patients who preferred a change was higher in the group taking the OD tablets with water. CONCLUSIONS: This study indicated that the degree of satisfaction with taste, flavor, ease of ingestion, and convenience, as well as overall satisfaction, in addition to motivation to continue drug intake and sense of confidence were greater for OD tablets than for the existing edoxaban film-coated tablets. Edoxaban OD tablet is a promising formulation for inducing greater patient adherence to medication and therefore ensures better treatment response. TRIAL REGISTRATION: UMIN-CTR UMIN000028788, registered 23-Aug-2017.

A direct oral anticoagulant edoxaban accelerated fibrinolysis via enhancement of plasmin generation in human plasma: dependent on thrombin-activatable fibrinolysis inhibitor.

A direct oral anticoagulant, edoxaban, is as effective as vitamin K antagonists for the treatment of venous thromboembolism (VTE). However, the mechanism underlying the treatment effect on VTE remains to be determined. The aims of this study were to evaluate the effect of edoxaban on tissue plasminogen activator (t-PA)-induced clot lysis in human plasma and to determine the roles of plasmin and thrombin-activatable fibrinolysis inhibitor (TAFI) in the profibrinolytic effect by edoxaban. Pooled human normal plasma or TAFI-deficient plasma (containing 180 ng/mL t-PA and 0.1 nM thrombomodulin) was mixed with edoxaban or an activated TAFI inhibitor, potato tuber carboxypeptidase inhibitor (PCI). Clot was induced by adding tissue factor and phospholipids. Clot lysis time and plasma plasmin-α2 antiplasmin complex (PAP) concentration were determined. Clot structure was imaged with a scanning electron microscope. In normal plasma, edoxaban at clinically relevant concentrations (75, 150, and 300 ng/mL) and PCI significantly shortened clot lysis time. PCI increased PAP concentration and a correlation between PAP concentration and percent of clot lysis was observed. Edoxaban also dose-dependently elevated PAP concentration. In TAFI-deficient plasma, the effects of edoxaban and PCI on clot lysis and PAP concentration were markedly diminished as compared with normal plasma. Fibrin fibers were thinner in clots formed in the presence of edoxaban. In conclusion, edoxaban at clinically relevant concentrations accelerates t-PA-induced fibrinolysis via increasing plasmin generation in human plasma. The effects of edoxaban is mainly dependent on TAFI. The profibrinolytic effect of edoxaban might contribute to the efficacy for the treatment of VTE.

Responses of prothrombin time and activated partial thromboplastin time to edoxaban in Japanese patients with non-valvular atrial fibrillation: characteristics of representative reagents in Japan (CVI ARO 7).

The aims of this study were to determine the distribution of plasma concentration of edoxaban (PC-Ed) with their 90% interval (on therapy range) and its correlation with anticoagulation markers in patients with non-valvular atrial fibrillation (NVAF). Consecutive 97 NVAF patients under edoxaban therapy were evaluated (60/30 mg dose, n = 48/49; men/women, n = 71/26; age, 69 years). CHADS2 score 0, 1, and ≥ 2 were 27%, 44%, and 29%, respectively. The mean (90% interval) of PC-Ed by LC-MS/MS was 194.3 (49.4-345.3) and 17.0 (4.8-40.7) ng/mL at peak (2-4 h post-dose) and trough (pre-dose), respectively. Correlation of prothrombin time (PT) with PC-Ed was higher than that of activated partial thromboplastin time (aPTT). Among 6 PT reagents, Coagupia PT-N and Simplastin Excel S (both PT reagents) showed the highest predictive capability for the upper outlier of PC-Ed at peak and trough. Among 4 aPTT reagents, only Thrombocheck APTT measured at peak had a significant predictive capability. When using PT reagents, both peak and trough sampling showed a similar predictive capability for the upper outliers of PC-Ed with a high sensitivity, but a relatively low specificity. We demonstrated the distributions of plasma concentration, PT with 6 reagents, and aPTT with 4 reagents under edoxaban therapy in Japanese patients with NVAF, showing their 90% intervals. For predicting the upper outlier of PC-Ed, PT was more sensitive compared with aPTT, whereas predicting capability for the outliers of PC-Ed was mostly similar between peak and trough samplings among PT reagents (UMIN 000032492).

Prevention of Stent Thrombosis in Rats by a Direct Oral Factor Xa Inhibitor Edoxaban.

BACKGROUND/AIMS: Stent thrombosis is a serious complication after percutaneous coronary intervention and femoropopliteal endovascular intervention. The aim of this study was to determine the antithrombotic effects of a direct factor Xa inhibitor edoxaban alone or in combination with antiplatelet agents in a rat model of stent thrombosis. METHODS: Stainless steel stents (4 stents per rat) were placed in an extracorporeal arteriovenous shunt. The shunt was inserted into the carotid artery and the jugular vein in each rat to circulate blood. Stent thrombosis was induced by exposing the stents to arterial blood for 30 min. Protein content of the thrombus was measured. Edoxaban and antiplatelet agents (aspirin, clopidogrel, and ticagrelor) were orally administered before the thrombus induction. RESULTS: Edoxaban (0.3-3 mg/kg), clopidogrel (1-10 mg/kg), aspirin (10-100 mg/kg), and ticagrelor (0.3-3 mg/kg) exerted significant and dose-dependent antithrombotic effects in a rat stent thrombosis model. The effect of edoxaban was comparable to that of antiplatelet agents. The combination of submaximal doses of edoxaban and clopidogrel or aspirin significantly potentiated the antithrombotic effects compared with antiplatelet agents alone. CONCLUSION: These results suggest that edoxaban alone and in combination with clopidogrel or aspirin are promising antithrombotic therapies for the prevention of stent thrombosis.

A direct oral factor Xa inhibitor edoxaban ameliorates neointimal hyperplasia following vascular injury and thrombosis in apolipoprotein E-deficient mice.

Vascular injury activates the coagulation cascade. Some studies report that coagulation factor Xa and thrombin are implicated in proliferation of vascular smooth muscle cells and neointimal hyperplasia after vascular injury. The aim of this study was to determine the effect of an oral direct factor Xa inhibitor, edoxaban, on neointimal hyperplasia following the carotid artery injury in apolipoprotein E (ApoE)-deficient mice. Vascular injury was induced by the application of 10% ferric chloride to the carotid artery for 3 min in ApoE-deficient mice. After vascular injury, all animals were fed with high-cholesterol chow for 6 weeks. Edoxaban at 15 mg/kg was orally administered to the mice 1 h before (n = 10) or 1 h after (n = 9) ferric chloride injury, and thereafter 10 mg/kg edoxaban was orally administered b.i.d. for 6 weeks. Thrombus formation and neointimal hyperplasia were evaluated. Treatment with 15 mg/kg edoxaban before vascular injury almost completely inhibited thrombus formation, and following chronic administration of edoxaban significantly suppressed neointimal hyperplasia. In the mice treated with edoxaban after vascular injury, there was wide interindividual variability. In some mice (four out of nine) the neointimal hyperplasia was inhibited like in edoxaban-pretreated mice, but there was no statistical difference compared with control. This study demonstrated that inhibition of the coagulation and thrombosis by edoxaban ameliorated neointimal hyperplasia caused by vascular injury and high-cholesterol diets in ApoE-deficient mice. This suggests that factor Xa has a crucial role in the formation of neointima following vascular injury.The abstract should be followed by 3-4 bullet points that highlight major findings. The final bullet point should emphasize future directions for research.

Generation and characterization of tissue-type plasminogen activator transgenic rats.

To address a species difference in the responsiveness to human recombinant tissue-type plasminogen activator (rt-PA) between rats and humans, tPA transgenic (Tg) rats were generated and characterized. In the rats, transcriptional regulation of tPA was designed under the control of the endogenous tPA promoter. There were no significant differences in hematological parameters between the tPA Tg and non Tg rats. Plasma tPA concentration was significantly increased and serum free PAI-1 was significantly decreased in the tPA Tg rats. Significant overexpression of tPA mRNA in five major organs was also confirmed in the tPA Tg rats. In contrast, the extent of tPA mRNA induction by pathophysiological stimuli (focal cerebral ischemia) was comparable in the two strains. Earlier increase in the plasma D-Dimer level was observed in the tPA Tg rats in a model of thromboembolism compared with the non Tg rats. On the other hand, there was no statistically significant prolongation of bleeding time in a rat model of bleeding between the two strains. rt-PA showed dose-related blood flow restoration in a rat model of thromboembolic stroke in the tPA Tg rats from a dose (1 mg/kg, i.v.) similar to clinical doses for human stroke patients. In conclusion, tPA Tg rats, in which tPA is overexpressed and endogenous fibrinolytic activity is enhanced without hemostatic abnormality, were generated. tPA Tg rats would be beneficial for the pharmacological and the toxicological evaluation of rt-PA and other various fibrinolytic enhancers.

Correction to: Generation and characterization of tissue-type plasminogen activator transgenic rats.

In the original publication of the article, the sentence in "Result" section have been incorrectly published as: "Three lines of tPA Tg rats were generated and analyzed by Southern blotting to confirm the presence of the transgene in genomic DNA. When rat DNA was digested with EcoRI and hybridized to the tPA probe described in "Materials and methods", a 1.0 kb band was detected (Fig. 1a, b). One founder line was selected because of its high copy number (about ten copies) of tPA gene and itansgene) and 4.4 kb (endogenous gene) reding appearance, body weight, hematology, and systematization." The corrected sentence should read as: "Three lines of tPA Tg rats were generated and analyzed by Southern blotting to confirm the presence of the transgene in genomic DNA. When rat DNA was digested with EcoRI and hybridized to the tPA probe described in "Materials and methods", a 1.0 kb band was detected (Fig. 1a, b). One founder line was selected because of its high copy number (about ten copies) of tPA gene and its lack of detectable abnormal findings, including appearance, body weight, hematology, and systematization." The original article has been corrected.