Head-to-head ex vivo comparison of clinically used direct anticoagulant drugs

An imbalance in coagulation is associated with cardiovascular events. For prevention and treatment, anticoagulants, currently mainly xabans and gatrans, are used. The purpose of the present study was to provide a head-to-head comparison since there are no studies directly evaluating these novel anticoagulants. An additional aim was to find whether selected anthropological and biochemical factors can affect their anticoagulant properties as they are used in fixed doses. In this cross-sectional study, blood from 50 generally healthy donors was collected, and coagulation responses to dabigatran, argatroban, rivaroxaban, and apixaban, at a concentration of 1 μM, were analyzed. Heparin was used as a positive control. Prothrombin time (PT) expressed as international normalized ratio (INR) and activated partial thromboplastin time (aPTT) were measured and compared. Rivaroxaban was the most active according to PT/INR while argatroban according to aPTT. The ex vivo anticoagulant effect measured by INR correlated inversely with body mass index (BMI) in all four anticoagulants tested. Shortening of aPTT was associated with higher cholesterol and triglyceride levels. No sex-related differences were observed in response to the anticoagulant treatments. As this was an ex vivo study and pharmacokinetic factors were not included, the influence of BMI is of high therapeutic importance.

Association of prothrombin time, thrombin time and activated partial thromboplastin time levels with preeclampsia: a systematic review and meta-analysis

BACKGROUND

Preeclampsia (PE), an obstetric disorder, remains one of the leading causes of maternal and infant mortality worldwide. In individuals with PE, the coagulation-fibrinolytic system is believed to be among the most significantly impacted systems due to maternal inflammatory responses and immune dysfunction. Therefore, this systematic review and meta-analysis aimed to assess the association of prothrombin time (PT), thrombin time (TT) and activated partial thromboplastin time (APTT) levels with preeclampsia.

METHODS

This systematic review and meta-analysis was conducted in accordance with the PRISMA guidelines. Articles relevant to the study, published from July 26, 2013, to July 26, 2023, were systematically searched across various databases including PubMed, Scopus, Embase, and Hinari. The methodological quality of the articles was evaluated using the Joanna Briggs Institute critical appraisal checklist. Utilizing Stata version 14.0, a random-effects model was employed to estimate the pooled standardized mean difference (SMD) along with the respective 95% CIs. The I2 statistics and Cochrane Q test were utilized to assess heterogeneity, while subgroup analyses were performed to explore its sources. Furthermore, Egger's regression test and funnel plot were employed to assess publication bias among the included studies.

RESULTS

A total of 30 articles, involving 5,964 individuals (2,883 with PE and 3,081 as normotensive pregnant mothers), were included in this study. The overall pooled SMD for PT, APTT, and TT between PE and normotensive pregnant mothers were 0.97 (95% CI: 0.65-1.29, p < 0.001), 1.05 (95% CI: 0.74-1.36, p < 0.001), and 0.30 (95% CI: -0.08-0.69, p = 0.11), respectively. The pooled SMD indicates a significant increase in PT and APTT levels among PE patients compared to normotensive pregnant mothers, while the increase in TT levels among PE patients was not statistically significant.

CONCLUSIONS

The meta-analysis underscores the association between PE and prolonged PT and APTT. This suggests that evaluating coagulation parameters like PT, APTT, and TT in pregnant women could offer easily accessible and cost-effective clinical indicators for assessing PE. However, multicenter longitudinal studies are needed to evaluate their effectiveness across various gestational weeks of pregnancy.

Alteration of prothrombin time in Plasmodium falciparum and Plasmodium vivax infections with different levels of severity: a systematic review and meta-analysis

Malaria infection leads to hematological abnormalities, including deranged prothrombin time (PT). Given the inconsistent findings regarding PT in malaria across different severities and between Plasmodium falciparum and P. vivax, this study aimed to synthesize available evidence on PT variations in clinical malaria. A systematic literature search was performed in PubMed, Embase, Scopus, Ovid, and Medline from 27 November 2021 to 2 March 2023 to obtain studies documenting PT in malaria. Study quality was evaluated using the Joanna Briggs Institute checklist, with data synthesized through both qualitative and quantitative methods, including meta-regression and subgroup analyses, to explore heterogeneity and publication bias. From 2767 articles, 21 studies were included. Most studies reported prolonged or increased PT in malaria patients compared to controls, a finding substantiated by the meta-analysis (P < 0.01, Mean difference: 8.86 s, 95% CI 5.32-12.40 s, I2: 87.88%, 4 studies). Severe malaria cases also showed significantly higher PT than non-severe ones (P = 0.03, Hedges's g: 1.65, 95% CI 0.20-3.10, I2: 97.91%, 7 studies). No significant PT difference was observed between P. falciparum and P. vivax infections (P = 0.88, Mean difference: 0.06, 95% CI - 0.691-0.8, I2: 65.09%, 2 studies). The relationship between PT and malaria-related mortality remains unclear, underscoring the need for further studies. PT is typically prolonged or increased in malaria, particularly in severe cases, with no notable difference between P. falciparum and P. vivax infections. The inconsistency in PT findings between fatal and non-fatal cases highlights a gap in current understanding, emphasizing the need for future studies to inform therapeutic strategies.

Modified application of SAMe-TT2R2 scoring system in Asian patients with atrial fibrillation for the selection of oral anticoagulants

BACKGROUND/AIMS

The SAMe-TT2R2 score is used for assessing anticoagulation control (AC) quality with warfarin. However, it is hard to apply SAMe-TT2R2 score in Asian patients with atrial fibrillation (AF), because it has not been proven in those populations. This study aimed to validate the SAMe-TT2R2 score in Asian patients with AF and suggest a modified SAMe- TT2R2 score for this population.

METHODS

We analyzed 710 Korean patients with AF who were using warfarin. The AC quality was assessed as the mean time in therapeutic range (TTR). Each component of SAMe-TT2R2 score was evaluated for the relationship with AC. Further clinical factors that predict AC were analyzed. Identified factors were re-assorted and constructed as SA2Me-TTR scoring system.

RESULTS

Of the components of the SAMe-TT2R2 score, female, age, and rhythm control were associated with AC. Heart failure and renal insufficiency were newly identified factors associated with AC. The modified SA2Me-TTR score was reconstructed with the relevant risk factors (S, female gender, 1 point; A, age < 60 yr, 2 points; Me, medical history of heart failure, 1 point; T, treatment for rhythm control, 1 point; T, history of stroke or transient ischemic attack, 1 point; R, renal insufficiency, 1 point). The modified SA2Me-TTR score demonstrated an excellent relationship with the grading of AC. The modified SA2Me-TTR score ≤ 1 identified patients with good AC (hazard ratio 2.46, 95% CI 1.75-3.47).

CONCLUSION

The modified SA2Me-TTR score was useful for guiding oral anticoagulants selection in Asian patients with AF.

Whole blood PT/aPTT assay based on non-contact drop-of-sample acoustic tweezing spectroscopy

Most coagulation tests are photo-optical turbidimetric assays that require the removal of cellular components from whole blood for optical clearing. If the resulting blood plasma samples are hemolyzed, they may become unsuitable for turbidimetric analysis. To resolve this issue, whole-blood analogs to plasma turbidimetric assays need to be developed. Using samples collected from non-smokers (normal group), smokers (thrombotic group), and hemophilia A (bleeding group) patients, we demonstrate that the reaction time assessed from whole blood viscosity data of the drop-of-blood acoustic tweezing spectroscopy (ATS) technique strongly correlates (Rp ≥ 0.95) with PT/aPTT values obtained from plasma turbidimetric data. Linear correlation (Rp ≥ 0.88) was also obtained between the viscous and elastic outputs of the ATS technique and the fibrinogen concentration. The integration of ATS data enabled the assessment of the functional level of fibrin cross-linkers such as factor XIII. Overall, ATS allows comprehensive sample-sparing analysis of whole blood coagulation for reliable and safe diagnosis of bleeding/thrombosis risks.

Clot Waveform Analysis for Hemostatic Abnormalities

Clot waveform analysis (CWA) observes changes in transparency in a plasma sample based on clotting tests such as activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT). Evidence indicates that not only an abnormal waveform but also peak times and heights in derivative curves of CWA are useful for the evaluation of hemostatic abnormalities. Modified CWA, including the PT with APTT reagent, dilute PT (small amount of tissue factor [TF]-induced clotting factor IX [FIX] activation; sTF/FIXa), and dilute TT, has been proposed to evaluate physiological or pathological hemostasis. We review routine and modified CWA and their clinical applications. In CWA-sTF/FIXa, elevated peak heights indicate hypercoagulability in patients with cancer or thrombosis, whereas prolonged peak times indicate hypocoagulability in several conditions, including clotting factor deficiency and thrombocytopenia. CWA-dilute TT reflects the thrombin burst, whereas clot-fibrinolysis waveform analysis reflects both hemostasis and fibrinolysis. The relevance and usefulness of CWA-APTT and modified CWA should be further investigated in various diseases.

Effect of chamomile intake on blood coagulation tests in healthy volunteers: a randomized, placebo-controlled, crossover trial

BACKGROUND

Chamomile is consumed worldwide for enjoyment and its potentially desirable properties. Widespread patient resource websites, however, discourage preoperative chamomile intake, lest bleeding could worsen. This precaution, though, stems largely from indirect evidence in one case report. To evaluate if chamomile ingestion impacts coagulation assays via coumarin-like substances, we designed a randomized, placebo-controlled, crossover study.

MATERIALS AND METHODS

Healthy volunteers were randomized to three interventions in a cross-over-design spanning 5 weeks per subject. Interventions included 7-day consumption of chamomile tea (3 tea bags × 3 times daily = 9 tea bags daily), a chamomile extract capsule (3 times daily), or a placebo capsule (3 times daily). A 7-day washout period elapsed between intervention periods. The primary outcome was the change in prothrombin time (PT) before vs. after each intervention. Secondary outcomes included changes in the international normalized ratio (INR), activated partial thromboplastin time (aPTT), thrombin time (TT), reptilase time (RT), and fibrinogen (FG) surrounding each intervention.

RESULTS

All 12 enrolled subjects were randomized and completed the study. The primary outcome of PT change (mean ± SD) was similar across interventions (chamomile tea =  - 0.2 ± 0.4 s, extract capsule =  - 0.2 ± 0.4 s, and placebo capsule = 0.1 ± 0.5 s; p = 0.34). INR change was 0 s (p = 0.07) for each intervention. The aPTT, TT, RT, and FG, did not change significantly across interventions (p = 0.8, p = 0.08, p = 0.8, and p = 0.2 respectively).

CONCLUSIONS

Chamomile intake by tea or capsule does not prolong PT. These findings challenge the notion to avoid perioperative chamomile intake in patients not taking warfarin.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05006378; Principal Investigator: Jonathon Schwartz, M.D.; Registered August 16, 2021.

Clinical association between coagulation indicators and bone metastasis in patients with gastric cancer

BACKGROUND

Bones are one of the most common target organs for cancer metastasis. Early evaluation of bone metastasis (BM) status is clinically significant. Cancer patients often experience a hypercoagulable state.

AIM

To evaluate the correlation between coagulation indicators and the burden of BM in gastric cancer (GC).

METHODS

We conducted a single-center retrospective study and enrolled 454 patients. Clinical information including routine blood examination and coagulation markers were collected before any treatment. Patients were grouped according to the status of BM. Receiver operating characteristic curves were used to assess diagnostic performance and determine the optimal cutoff values of the above indicators. Cutoff values, sensitivity and specificity were based on the maximum Youden index. Univariate and multivariate logistic regression analyses were used to evaluate the relationships between biomarkers and BM.

RESULTS

Of the 454 enrolled patients, 191 patients were diagnosed with BM. The receiver operating characteristic curve analysis suggested that prothrombin time (PT) [cutoff: 13.25; sensitivity: 0.651; specificity: 0.709; area under receiver operating characteristic curve (AUC) = 0.738], activated partial thromboplastin time (aPTT) (cutoff: 35.15; sensitivity: 0.640; specificity: 0.640; AUC = 0.678) and fibrin degradation products (FDP) (cutoff: 2.75; sensitivity: 0.668; specificity: 0.801; AUC = 0.768) act as novel predictors for BM. Based on multivariate logistic regression analysis, the results showed the independent correlation between PT [odds ratio (OR): 3.16; 95% confidence interval (CI): 1.612-6.194; P = 0.001], aPTT (OR: 2.234; 95%CI: 1.157-4.313; P = 0.017) and FDP (OR: 3.17; 95%CI: 1.637-6.139; P = 0.001) and BM in patients with GC. Moreover, age, carcinoembryonic antigen, erythrocyte and globulin were found to be significantly associated with BM.

CONCLUSION

Coagulation markers, namely PT, aPTT and FDP, might be potential predictors for screening BM in patients with GC.

Comparing modified Lee and White method against 20-minute whole blood clotting test as bedside coagulation screening test in snake envenomation victims

Background

Twenty-minute whole blood clotting test (20WBCT) and Modified Lee and White (MLW) method are the most routinely employed bedside tests for detecting coagulopathic snake envenomation. Our study compared the diagnostic utility of MLW and 20WBCT for snakebite victims at a tertiary care hospital in Central Kerala, South India.

Methods

This single-center study recruited 267 patients admitted with snake bites. 20WBCT and MLW were performed simultaneously at admission along with the measurement of Prothrombin Time (PT). The diagnostic utility of 20WBCT and MLW was determined by comparing the sensitivity (Sn), specificity (Sp), positive and negative predictive values, likelihood ratios, and accuracy at admission with an INR value > 1.4.

Results

Out of 267 patients, 20 (7.5%) patients had VICC. Amongst those who had venom-induced consumption coagulopathy (VICC), MLW was prolonged for 17 patients, (Sn 85% 95% confidence interval [CI]: 61.1-96.0) whereas 20WBCT was abnormal for 11 patients (Sn 55%, 95% CI: 32.04-76.17). MLW and 20WBCT were falsely positive for the same patient (Sp 99.6%, 95% CI: 97.4-99.9%).

Conclusion

MLW is more sensitive than 20WBCT to detect coagulopathy at the bedside amongst snakebite victims. However, further studies are necessary for standardizing bedside coagulation tests in snakebite cases.

Effect of fat emulsion administration on blood coagulation in terminal lung cancer patients

Objectives

Patients with cancer, especially those with lung cancer, are at high risk of developing thrombosis. Intralipos^® infusion 20% is contraindicated for thrombosis, and there is no consensus on whether it can be safely used in cases of advanced cancer. We conducted a retrospective observational study to elucidate the impact of fat emulsion administration on blood coagulation in patients with terminal lung cancer.

Methods

The subjects were patients with terminal lung cancer in the Department of Surgery and Palliative Medicine, Fujita Health University Nanakuri Memorial Hospital between January 2016 and December 2019. We compared changes in their blood coagulation profile before hospitalization and one month later.

Results

There were a total of 213 patients with lung cancer-139 who were administered fat emulsion and 74 who were not-with no significant differences in baseline characteristics. In the fat emulsion administration group (n=27), the prothrombin time-international normalized ratio (PT-INR) and activated partial thromboplastin time (APTT), respectively, were 1.17±0.26 (mean±standard deviation) and 30.5±5.0 s at hospitalization and 1.16±0.12 and 31.2±4.2 s one month later with no significant differences. In the non-administration group (n=6), the PT-INR and APTT, respectively, were 1.44±0.43 and 30.6±5.2 s before hospitalization and 1.28±0.18 and 33.0±7.5 s one month later with no significant differences.

Conclusions

We did not identify any changes in PT-INR and APTT after fat emulsion administration in patients with terminal lung cancer. There were also no new cases of thrombosis, suggesting that fat emulsions were administered safely in patients with terminal lung cancer.

Estimating the measurement uncertainties of the international sensitivity index of 12 thromboplastins through Monte Carlo simulation

BACKGROUND

Measurement uncertainty (MU) estimation has become an important process in clinical laboratories; however, calculating the MUs of the international sensitivity index (ISI) of thromboplastins is difficult because of the complex mathematical calculations required in calibration. Therefore, this study quantifies the MUs of ISIs through the Monte Carlo simulation (MCS), which involves random sampling of numerical values to solve a complex mathematical calculation.

METHODS

Eighty blood plasmas and commercially available certified plasmas (ISI Calibrate) were used to assign the ISIs of each thromboplastin. Prothrombin times were measured using reference thromboplastin and 12 commercially available thromboplastins (Coagpia PT-N, PT Rec, ReadiPlasTin, RecombiPlasTin 2G, PT-Fibrinogen, PT-Fibrinogen HS PLUS, Prothrombin Time Assay, Thromboplastin D, Thromborel S, STA-Neoplastine CI Plus, STA-Neoplastine R 15, and STA-NeoPTimal) with two automated coagulation instruments: ACL TOP 750 CTS (ACL TOP; Instrumentation Laboratory, Bedford, MA, USA) and STA Compact (Diagnostica Stago, Asnières-sur-Seine, France). Then, the MUs of each ISI were simulated through MCS.

RESULTS

The MUs of ISIs ranged from 9.7 % to 12.1 % and 11.6 % to 12.0 % when blood plasma and ISI Calibrate were used, respectively. For some thromboplastins, the ISI claimed by manufacturers significantly differed from the estimated results.

CONCLUSIONS

MCS is adequate to estimate the MUs of ISI. These results would be clinically useful for estimating the MUs of the international normalized ratio in clinical laboratories. However, the claimed ISI significantly differed from the estimated ISI of some thromboplastins. Therefore, manufacturers should provide more accurate information about the ISI value of thromboplastins.

Sepsis-related coagulopathy treatment based on the disseminated intravascular coagulation diagnostic criteria: a post-hoc analysis of a prospective multicenter observational study

BACKGROUND

The development of disseminated intravascular coagulation (DIC) in patients with sepsis has been repeatedly confirmed as a factor associated with poor prognosis. Anticoagulant therapy has been expected to improve sepsis patient outcomes, whereas no randomized controlled trials have demonstrated the survival benefit of anticoagulant therapies in non-specific overall sepsis. Patient selection based on the component of "high disease severity" in addition to "sepsis with DIC" has recently proved important in identifying appropriate targets for anticoagulant therapy. The aims of this study were to characterize "severe" sepsis DIC patients and to identify the patient population benefiting from anticoagulant therapy.

METHODS

This retrospective sub-analysis of a prospective multicenter study included 1,178 adult patients with severe sepsis from 59 intensive care units in Japan from January 2016 to March 2017. We examined the association of patient outcomes, including organ dysfunction and in-hospital mortality, with the DIC score and prothrombin time-international normalized ratio (PT-INR), one of the components of the DIC score, using multivariable regression models including the cross-product term between these indicators. Multivariate Cox proportional hazard regression analysis with non-linear restricted cubic spline including a three-way interaction term (anticoagulant therapy × the DIC score × PT-INR) was also performed. Anticoagulant therapy was defined as the administration of antithrombin, recombinant human thrombomodulin, or their combination.

RESULTS

In total, we analyzed 1013 patients. The regression model showed that organ dysfunction and in-hospital mortality deteriorated with higher PT-INR values in the range of < 1.5 and that this trend was more pronounced with higher DIC scores. Three-way interaction analysis demonstrated that anticoagulant therapy was associated with better survival outcome in patients with a high DIC score and high PT-INR. Furthermore, we identified a DIC score ≥ 5 and PT-INR ≥ 1.5 as the clinical threshold for identification of optimal targets for anticoagulant therapy.

CONCLUSIONS

The combined use of the DIC score and PT-INR helps in selecting the optimal patient population for anticoagulant therapy in sepsis-induced DIC. The results obtained from this study will provide valuable information regarding the study design of randomized controlled trials examining the effects of anticoagulant therapy for sepsis.

TRIAL REGISTRATION

UMIN-CTR, UMIN000019742. Registered on November 16, 2015.

Preoperative coagulation screening tests in pediatric patients: Clinical relevance and hemorrhagic outcomes of abnormal results

PURPOSE

Coagulation screening tests in children are still frequently performed in many countries to evaluate bleeding risk. The aim of this study was to assess the management of unexpected prolongations of the activated partial thromboplastin time (APTT) and prothrombine time (PT) in children prior to elective surgery, and the perioperative hemorrhagic outcomes.

METHODS

Children with prolonged APTT and/or PT who attended a preoperative anesthesia consultation from January 2013 to December 2018 were included. Patients were grouped according to whether they were referred to a Hematologist or were scheduled to undergo surgery without further investigation. The primary endpoint was to compare perioperative bleeding complications.

RESULTS

1835 children were screened for eligibility. 102 presented abnormal results (5.6%). Of them, 45% were referred to a Hematologist. Significant bleeding disorders were associated with a positive bleeding history, odds ratio of 51 (95% CI 4.8-538.5, P=.0011). No difference in perioperative hemorrhagic outcomes were found between the groups. An additional cost of 181 euros per patient and a preoperative median delay of 43 days was observed in patients referred to Hematology.

CONCLUSIONS

Our results suggest that hematology referral has limited value in asymptomatic children with a prolonged APTT and/or PT. Hemorrhagic complications were similar among patients referred and not referred to Hematology. A positive personal or family bleeding history can help identify patients with a higher bleeding risk, thus it should guide the need for coagulation testing and hematology referral. Further efforts should be made to standardize preoperative bleeding assessments tools in children.

Significance of abnormal blood coagulation in patients with chronic myelomonocytic leukemia

In a retrospective study, we analyzed the prevalence of subnormal prothrombin time (PT) values in 104 patients with chronic myelomonocytic leukemia (CMML), their potential prognostic impact, and potential correlations with clinicolaboratory features. Reduced PT values (< 70%) were found in 45/104 (43%) patients. The median survival of patients with reduced PT values was significantly shorter than in patients with normal PT (19 vs. 49 months, p = 0.006). Patients with reduced PT had higher leukocyte counts, a higher proportion of circulating blast cells, and lower platelet counts. In patients for whom clinical information was available, there was no difference in the incidence of bleeding complications between patients with or without reduced PT. Our results show a high prevalence of plasmatic coagulation abnormalities in patients with CMML, which were associated with laboratory features of advanced disease. Moreover, subnormal PT values were identified as a new prognostic marker. Reduced PT values do not seem to have a clinical impact regarding bleeding complications.

Toxicological responses to sublethal anticoagulant rodenticide exposure in free-flying hawks

An important component of assessing the hazards of anticoagulant rodenticides to non-target wildlife is observations in exposed free-ranging individuals. The objective of this study was to determine whether environmentally realistic, sublethal first-generation anticoagulant rodenticide (FGAR) exposures via prey can result in direct or indirect adverse effects to free-flying raptors. We offered black-tailed prairie dogs (Cynomys ludovicianus) that had fed on Rozol® Prairie Dog Bait (Rozol, 0.005% active ingredient chlorophacinone, CPN) to six wild-caught red-tailed hawks (RTHA, Buteo jamaicensis), and also offered black-tailed prairie dogs that were not exposed to Rozol to another two wild-caught RTHAs for 7 days. On day 6, blood was collected to determine CPN's effects on blood clotting time. On day 7, seven of the eight RTHAs were fitted with VHF radio telemetry transmitters and the RTHAs were released the following day and were monitored for 33 days. Prothrombin time (PT) and Russell's viper venom time confirmed that the CPN-exposed RTHAs were exposed to and were adversely affected by CPN. Four of the six CPN-exposed RTHAs exhibited ptiloerection, an indication of thermoregulatory dysfunction due to CPN toxicity, but no signs of intoxication were observed in the reference hawk or the remaining two CPN-exposed RTHAs. Of note is that PT values were associated with ptiloerection duration and frequency; therefore, sublethal CPN exposure can directly or indirectly evoke adverse effects in wild birds. Although our sample sizes were small, this study is a first to relate coagulation times to adverse clinical signs in free-ranging birds.

Hemostatic Testing in Companion Exotic Mammals

The mammalian hemostatic system is highly conserved, and companion exotic mammals are commonly used as biomedical models for normal and disordered hemostasis. Challenges associated with sample collection, test validation, and test interpretation have limited the use of these tests in clinical exotic animal practice. However, evaluation of platelet counts, coagulation screening times, and fibrin(ogen) degradation products can be valuable for monitoring exotic patients with a range of disease presentations including intoxications, anemia, systemic viral disease, hepatopathy, and endocrinopathy.

Tigecycline-Associated Coagulopathy: A Single-Center Retrospective Analysis

INTRODUCTION

The purpose of this study was to assess clinical characteristics and risk factors for tigecycline-associated prothrombin time (PT) and activated partial thromboplastin time (aPTT) prolongation.

METHODS

We performed a retrospective analysis on coagulation parameters before and during tigecycline treatment in 55 patients in our hospital with severe infections, mainly pneumonia caused by Acinetobacter baumannii. Patients were divided into different groups according to prolongation of PT and aPTT, and clinical features involved were explored. Univariate and multivariable binary logistic regression analyses were used to identify risk factors for tigecycline-associated PT and aPTT increase.

RESULTS

We found that PT values increased from 12.73 ± 1.87 to 13.86 ± 2.06 during the treatment compared with premedication (p < 0.001), and the aPTT level prolonged significantly from 33.63 ± 11.24 to 38.15 ± 11.81 (p < 0.001). The multivariate analyses identified 2 variables that were associated with tigecycline-induced PT prolongation: albumin level (p = 0.018) and weight-adjusted tigecycline dosage (p = 0.005). In addition, treatment duration was the only risk factor for tigecycline-induced aPTT prolongation (p = 0.043).

CONCLUSION

Albumin level, weight-adjusted tigecycline dosage, treatment duration may serve as risk indicators for tigecycline-associated coagulation dysfunction. Physicians should be careful with coagulation disorder when prescribing tigecycline in clinical practice, especially in patients with risk factors.

Coagulation markers in patients with venous thromboembolism treated with 10 mg apixaban twice daily

Apixaban is used to treat venous thromboembolism (VTE) at 10 mg twice daily (BID) for 7 days, followed by 5 mg BID without dose adjustment, and non-valvular atrial fibrillation (NVAF) at 5 mg BID or 2.5 mg BID with dose adjustment criteria (DAC) including age, body weight, and renal function. The anti-factor Xa activity (AXA), prothrombin time (PT), and activated partial thromboplastin time (APTT) in patients with VTE receiving 10 mg BID of apixaban remains unclear. Twenty-six patients (70.8±15.4 years, 10 males) with VTE receiving 10 mg BID of apixaban were enrolled. The patients were divided into two groups based on whether they met the DAC of NVAF: DAC group (n=8) and non-DAC group (n=18). Trough and peak AXA values, PT, and APTT were measured at 10 mg BID dosage and then at 5 mg BID dosage. Coagulation markers in recipients of 10 mg BID therapy were significantly higher than those of 5 mg BID recipients. A significant and strong positive correlation was observed between AXA and PT at trough and peak times. The AXA values and PT in the DAC group were significantly higher than those in the non-DAC group. No significant inter-group differences were seen in APTT. This study provides the first report of AXA distribution in VTE patients receiving 10 mg BID of apixaban. Our findings indicate that coagulation markers may differ in patients with VTE-prescribed higher doses of apixaban and a DAC may be warranted in such patients.

Comprehensive Laboratory Data Analysis to Predict the Clinical Severity of Coronavirus Disease 2019 in 1,952 Patients in Daegu, Korea

Background

Laboratory parameter abnormalities are commonly observed in COVID-19 patients; however, their clinical significance remains controversial. We assessed the prevalence, characteristics, and clinical impact of laboratory parameters in COVID-19 patients hospitalized in Daegu, Korea.

Methods

We investigated the clinical and laboratory parameters of 1,952 COVID-19 patients on admission in nine hospitals in Daegu, Korea. The average patient age was 58.1 years, and 700 (35.9%) patients were men. The patients were classified into mild (N=1,612), moderate (N=294), and severe (N=46) disease groups based on clinical severity scores. We used chi-square test, multiple comparison analysis, and multinomial logistic regression to evaluate the correlation between laboratory parameters and disease severity.

Results

Laboratory parameters on admission in the three disease groups were significantly different in terms of hematologic (Hb, Hct, white blood cell count, lymphocyte%, and platelet count), coagulation (prothrombin time and activated partial thromboplastin time), biochemical (albumin, aspartate aminotransferase, alanine aminotransferase, lactate, blood urea nitrogen, creatinine, and electrolytes), inflammatory (C-reactive protein and procalcitonin), cardiac (creatinine kinase MB isoenzyme and troponin I), and molecular virologic (Ct value of SARS-CoV-2 RdRP gene) parameters. Relative lymphopenia, prothrombin time prolongation, and hypoalbuminemia were significant indicators of COVID-19 severity. Patients with both hypoalbuminemia and lymphopenia had a higher risk of severe COVID-19.

Conclusions

Laboratory parameter abnormalities on admission are common, are significantly associated with clinical severity, and can serve as independent predictors of COVID-19 severity. Monitoring the laboratory parameters, including albumin and lymphocyte count, is crucial for timely treatment of COVID-19.

Development and validation of a mobile application based on a machine learning model to aid in predicting dosage of vitamin K antagonists among Indian patients post mechanical heart valve replacement

Patients who undergo heart valve replacements with mechanical valves need to take Vitamin K Antagonists (VKA) drugs (Warfarin, Nicoumalone) which has got a very narrow therapeutic range and needs very close monitoring using PT-INR. Accessibility to physicians to titrate drugs doses is a major problem in low-middle income countries (LMIC) like India. Our work was aimed at predicting the maintenance dosage of these drugs, using the de-identified medical data collected from patients attending an INR Clinic in South India. We used artificial intelligence (AI) - machine learning to develop the algorithm. A Support Vector Machine (SVM) regression model was built to predict the maintenance dosage of warfarin, who have stable INR values between 2.0 and 4.0. We developed a simple user friendly android mobile application for patients to use the algorithm to predict the doses. The algorithm generated drug doses in 1100 patients were compared to cardiologist prescribed doses and found to have an excellent correlation.

Dramatically prolonged coagulation screening tests in a patient with positive lupus anticoagulant and monoclonal immunoglobulin M without bleeding manifestations

BACKGROUND

Concomitant presence of lupus anticoagulant (LA) and monoclonal immunoglobulin in the same patient is uncommon and the influence of this finding on coagulation results is still unknown.

CASE REPORT

We present a patient with a diagnosis of systemic lupus erythematosus (SLE) and secondary antiphospholipid syndrome (APS) with permanently positive LA who presented with accidental finding of newly discovered monoclonal IgM in a high concentration and dramatically prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT), without bleeding manifestations.

CONCLUSION

Concomitant presence of extremely prolonged PT and aPTT with unusual coagulation reaction kinetics, consistent LA ratio over the follow-up period and normalization of coagulation screening results with decreasing monoclonal IgM concentration elicited suspicion that PT and aPTT prolongation could be attributed to M-protein with antiphospholipid specificity. Low LA-sensitive aPTT reagent Actin FS demonstrated exceptional sensitivity, whereas human placental thromboplastin in contrast to recombinant reagents showed significantly lower sensitivity to monoclonal IgM with antiphospholipid specificity. Changes in the activity of SLE observed during the follow-up period were inversely related to monoclonal IgM concentration, while the presence of secondary APS was consistent. Described analytical interference on PT and aPTT without bleeding manifestation should point towards suspicion of previously unidentified monoclonal IgM with antiphospholipid sensitivity.

Copper concentrations are prevalently associated with antithrombin III, but also with prothrombin time and fibrinogen in patients with liver cirrhosis: A cross-sectional retrospective study

BACKGROUND

Concerning the link between copper excess and the pathogenesis of chronic liver diseases, its retention is reckoned to develop as a complication of cholestasis. Recently, it has been found that cholestatic liver injury involves largely inflammatory cell-mediated liver cell necrosis, with consequent reduced hepatic mass, more than occurring through direct bile acid-induced apoptosis. On the other hand, interference with protein synthesis could be expected to result, ending in an altered ability of the liver to retain copper. Little is known about the association between serum copper and clotting factors in cirrhotics. We aimed at studying a possible relationship between increased levels of copper and an aspect of the haemostatic process in liver cirrhosis patients, assessing an index of protein synthesis (albumin) and parameters of protein synthesis/coagulation/fibrinolysis, such as prothrombin time (PT), antithrombin (AT) III and fibrinogen.

METHODS

Records from 85 patients suffering from liver cirrhosis of various aetiology and different severity were retrospectively examined. Serum concentrations of copper were determined by atomic absorption spectrophotometer. An index of protein synthesis, such as albumin and parameters of both synthesis and coagulation/hypercoagulation such as PT %, AT III%, levels of fibrinogen were taken into account to study possible correlations to serum copper. The severity of cirrhosis was evaluated by the Child-Pugh (C-P) classification. The relationship among variables were studied by linear regression.

RESULTS

Copper levels of patients suffering from liver cirrhosis were increased respect to those of controls, 102.7+/-28.7 versus 80.4+/-19.5 mcg/dL, (P = .0009), independently from disease severity, and were positively predicted by PT% (P = 0. 017), fibrinogen (P = 0.007) and AT III% (P = 0.000), at linear regression. Among the previous parameters, to which serum albumin was added, the unique predictor of copper levels was AT III%, at multiple regression (P = 0. 010); AT III% was negatively predicted by the C-P classification (P = 0.000); copper levels, adjusted for C-P classification, were predicted by AT III% (P = 0.020) and fibrinogen concentrations, but not by PT% (P = 0.09).

CONCLUSION

The copper concentration is reckoned as responsible for production of the hydroxyl radicals. On the basis that oxidants may enhance the activity of the extrinsic coagulation cascade, ultimately leading to thrombin formation, via their combined effects on stimulation of tissue factor activity and inhibition of fibrinolytic pathways, the positive relationship of copper to coagulation/hypercoagulation parameters (mainly AT III) in our research could find a plausible interpretation.

A review article

The antithrombotic effect of vitamin K antagonists (VKA) depends on controlled lowering of the activity of factors (F) II and X whereas reductions in FVII and FIX play little role. PT-INR based monitoring, however, is highly influenced by FVII, which has the shortest half-life of vitamin K-dependent coagulation factors. Hence, variability in the anticoagulant effect of VKA may be partly secondary to an inherent flaw of the traditional monitoring test itself. The Fiix prothrombin time (Fiix-PT) is a novel test that is only sensitive to reductions in FII and FX and is intended to stabilize the VKA effect. Two clinical studies have now demonstrated that when warfarin is monitored with the Fiix-PT based normalized ratio (Fiix-NR) instead of PT-INR, anticoagulation is stabilized and less testing and fewer dose adjustments are needed. Furthermore, the relative risk of thromboembolism was reduced by 50-56% in these studies without an increase in major bleeding.

Alkaloidal extract from Carica papaya seeds ameliorates CCl4-induced hepatocellular carcinoma in rats

Background

Hepatocellular carcinoma (HCC) is the third cause of cancer-related mortality globally. However, available treatments are expensive and are associated with adverse effects or poor treatment outcomes in advanced disease. Meanwhile, plants like Carica papaya have demonstrated various biological activities that further studies may lead to the identification of newer and safer treatment options for HCC.

Aim

To evaluate the anticancer activity of an alkaloidal extract derived from Carica papaya seeds using rodent models of HCC.

Experimental procedure

Carica Papaya fruits were collected and authenticated. The seeds were isolated and air-dried. Alkaloidal extract was prepared from a 70% ethanol soxhlet crude extract and referred to as Carica papaya alkaloidal extract (CPAE). HCC was induced in 68 out of 84 healthy male Sprague Dawley rats by intraperitoneal injection of carbon tetrachloride (CCl₄) for 16 weeks. These rats were put into five groups of 10; Carica papaya alkaloidal extract [(CPAE) (50, 100, and 200 mg/kg), Lenvatinib (4 mg/kg)], 1% dimethyl sulphoxide (DMSO), and 2 untreated groups (control and model). A prophylaxis study was performed with 10 rats by co-administration of CPAE (200 mg/kg) and CCl₄ six hours apart for 16 weeks. Rats were sacrificed after a twelve-week treatment program under anesthesia for histological, hematological, and biochemical analyses.

Results and conclusion

CPAE (100 and 200 mg/kg) significantly restored weight loss (48.44 and 51.75% respectively), reduced tumor multiplicity, and dose-dependently reversed liver histomorphological changes induced by CCl₄ compared to the model group. The CPAE (100 and 200 mg/kg) further reduced bleeding time, improved prothrombin time and restored platelet count (p < 0.01) compared to the model. The CPAE (200 mg/kg) again significantly (p < 0.0001) reduced serum alpha-fetoprotein levels compared to the model group and prevented the establishment of HCC in rats when concerrently administered with CCl₄ in 16 weeks prophylactic study.

Antithrombotic property of an aqueous extract from Pseudocedrela kotschyi and Adenia cissampeloides

Background and purpose:

An aqueous extract from the root bark of Pseudocedrela kotschyi and aerial parts of Adenia cissampeloides has been proven in previous research to elicit significant anticoagulant property in vitro. This, therefore, indicates the potential usefulness of this extract in managing thromboembolic disease, a major global health risk. The aim of the present work was to establish the antithrombotic effect of a product made from extracts of the root bark of P. kotschyi and the aerial parts of A. cissampeloides (PAE).

Experimental approach:

The effect of PAE at 500-2000 mg/kg in inhibiting tail infarction and inflammation, as well as its effect on the microthrombi count, hematological, and coagulation profiles in a carrageenan-induced thrombosis model in Sprague-Dawley rats, was studied.

Findings/Results:

PAE significantly (P ≤ 0.01-0.001) reduced length of tail infarction and inflammation (redness, swelling, pain, and temperature). Histopathological studies revealed a significant reduction (P ≤ 0.0001) in microthrombi count in the liver and the lungs with PAE treatment. PAE treatment caused a marginal (P ≤ 0.01) increase in prothrombin time but resulted in a significant (P ≤ 0.01-0.0001) dose-dependent increase in activated partial thromboplastin time, with the hematological profile being normal.

Conclusion and implications:

PAE showed anticoagulant and antithrombotic effects in vivo, indicative of its potential benefit as a natural product, and cost-effective therapeutic option, and hence could be helpful in thromboembolic therapies.

Volumetric assessment and clinical predictors of cirrhosis in patients undergoing hepatectomy for hepatocellular carcinoma with presumed normal liver function

AIM

Indocyanine green retention rate at 15 min (ICGR15) is a frequently used indicator of liver function. Herein, clinicopathological characteristics of cirrhotic patients with normal ICGR15 value (< 10%) were investigated, as these patients have risk of postoperative liver insufficiency when receiving a major hepatic resection.

METHODS

Patients undergoing hepatectomy for hepatocellular carcinoma were divided into three groups: non-cirrhotic livers (Group A, n = 112): cirrhotic livers with ICGR15 < 10% (Group B, n = 71): and cirrhotic livers with ICGR15 > 10% (Group C, n = 296). Background characteristics and surgical outcomes were compared between groups. Functional liver volume (FLV) was computed using total liver volume and signal intensity ratio. Liver parenchymal cell volume ratio was measured in non-cancerous tissue obtained from resected specimens. Univariate and multivariate analyses were performed to detect clinical characteristics correlating with cirrhotic liver pathology with normal ICGR15.

RESULTS

There was no significant difference between groups in TLV. FLV was gradually reduced from Group A toward Group C. Liver parenchymal cell volume ratio was also gradually reduced from Group A toward Group C. Multivariate analysis revealed that platelet count (< 12 × 10⁴/mm³) (p = 0.001) and prothrombin time (< 80%) (p = 0.025) were significantly associated with cirrhotic liver pathology among patients with normal ICGR15.

CONCLUSION

Our results suggested that cirrhotic liver pathology despite normal liver function was characterized by slightly decreasing liver parenchyma as well as slight degree of fibrosis. Platelet count and PT% are useful for predicting liver cirrhosis with normal ICGR15.

Evaluation of the merit of the methanolic extract of Andrographis paniculata to supplement anti-snake venom in reversing secondary hemostatic abnormalities induced by Naja naja venom

Increasing evidence suggests a sizable involvement of hemotoxins in the morbidity associated with envenomation by the Indian spectacled cobra, Naja naja (N.N). This study investigates the ability of Indian polyvalent anti-snake venom (ASV), methanolic extract of Andrographis paniculata (MAP) and their combination in reversing the hemostatic abnormalities, viz. activated partial thromboplastin time(aPTT), prothrombin time(PT) and thrombin time(TT) in citrated plasma. These parameters were assessed in 2 groups of experiments. Group 1: Without the prior incubation of plasma with venom and Group 2: With prior incubation of plasma with venom for 90 min at 37°C. Venom caused significant (p < 0.001) prolongation in aPTT (175%), PT (49%) and TT (34%) in Group 1 and ASV could completely bring them back to normal. MAP showed a concentration-dependent reversal in aPTT, normalization of PT and prolongation of TT. When low concentration of ASV was supplemented with MAP, their combined effect in normalizing aPTT and PT improved by 37% and 26% respectively when compared to ASV alone. In Group 2, venom caused significant (p < 0.001) prolongation in aPTT (231%), PT (312%) and TT (245%). ASV had limited effect in reversing aPTT (52%), TT (31%) but completely normalized PT. MAP was marginally effective in reversing the prolonged aPTT and PT but caused further prolongation of TT. Combination of ASV and MAP was more effective than ASV alone in reversing venom-induced increase in aPTT (52%) and PT (29%). The study proved that, a drastic reduction of ASV by 70%, could be effectively supplemented by MAP in combating hemostatic abnormalities induced by NN venom.

Impact of inflammatory cell ratio, biomarkers, activated partial thromboplastin time and prothrombin time on chronic subdural haematoma severity and outcome

INTRODUCTION

Chronic subdural haematoma (CSH) has multifactorial mechanisms involved in its development and progression. Identifying readily available inflammatory and coagulation indices that can predict the prognosis of CSH will help in clinical care, prognosis, generating objective criteria for assessing efficacy of treatment strategies and comparisons of treatment efficacy between clinical studies. We conducted a study in which we evaluated the impact value of neutrophil to lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), inflammatory biomarkers (erythrocyte sedimentation rate and C-reactive protein), activated partial thromboplastin time (APTT), prothrombin time (PT) and international normalized ratio (INR) at presentation on CSH severity and outcome using Glasgow outcome scale (GOS), Markwalder grading scale (MGS) and Lagos brain disability examination scale (LABDES).

METHODS

We prospectively studied patients in a single healthcare system with clinical and radiological features of chronic subdural haematoma. Only patients who were managed surgically were recruited. The primary outcome was predictors of severe form CSH (using admission Glasgow coma scale score, MGS grade, inflammatory cells and biomarkers, APTT, PT, and INR) and outcome (using GOS, MGS and LABDES grades 3 months) with secondary outcome being mortality rate, 3 months following surgery. Good outcome was defined as GOS score > 3, LABDES score ≥ 40 at three months and MGS score < 2. Differences in categorical and continuous variables between groups were compared using Fisher's exact test or Chi-square test (χ2) analysis, one-way ANOVA or Kruskal-Wallis test (in case of non-normal distribution).

RESULTS

We included 61 patients with a male-to-female ratio of 2.6:1 and mean age of 57.5 ± 13.3 years (median 58 years; 27-83 years). The pre-op MGS grade was significantly associated with the LABDES (p = 0.034), GOS (p = 0.011) and post-op MGS (p = 0.007) grade. All the patients that died had elevated APTT and PT with low PLR. A low admission PLR was significantly associated with a poor outcome using the GOS (p = 0.001), MGS (p = 0.011) and LABDES grade (p = 0.006) (Table 3). A high APTT was also significantly associated with a worse outcome using GOS (p = 0.007), MGS (p = 0.007) and LABDES grade (p = 0.003). There were three (4.9%) deaths with post-mortem diagnosis of pulmonary embolism, chronic renal failure and irreversible craniocaudal herniation syndrome. All the patients that died had elevated APTT and PT with low PLR.

CONCLUSION

Patients' admission APTT, PT, INR and PLR are good predictors of outcome using the GOS. A high admission INR is also associated with a worse outcome using MGS and LABDES grade.

Can disseminated intravascular coagulation scores predict mortality in COVID-19 patients?

Objectives

Complications related to coronavirus disease 2019 (COVID-19) may lead to disseminated intravascular coagulation (DIC), which has been reported to be among the known causes of mortality in such patients. This study aims to analyse the incidence of DIC in COVID-19 non-survivors and to assess the association between DIC and its comorbidities.

Methods

The medical records of 154 non-survivors of COVID-19, hospitalised between April 2020 and July 2020, were retrospectively analysed. The International Society on Thrombosis and Haemostasis (ISTH) criteria for DIC were applied to identify the occurrence of coagulopathy. The receiver-operating characteristic (ROC) analysis was used to assess the association between DIC and its comorbidities.

Results

Out of 154 non-survivors, non-overt DIC was observed in 94.8% of the patients, whereas only 5.2% fulfilled the overt criteria of DIC with a mean age 64.6 years. The mortality rate was 4.5 times higher among men than women. The D-dimer level was >250 ng/ml in 68.8% of the patients including 88.9% of the non-overt and 100% of the overt DIC patients. Prothrombin time (PT) in non-overt and overt DIC cases was 17.3 s and 24.4 s, respectively. Thrombotic event and chronic kidney disease were found to be the main predictors of DIC (p < 0.0001 and 0.03, respectively) followed by diabetes mellitus (DM) and hypertension (statistically insignificant).

Conclusions

Our study concludes that the ISTH DIC score cannot predict mortality as the COVID-19 related DIC differs from the sepsis-induced DIC. Among the seriously ill, older patients with comorbidities, increased levels of D-dimer and prolonged PT are more reliable parameters among COVID-19 non-survivors.

Bias and uncertainty of the International Normalized Ratio determined with a whole blood point-of-care prothrombin time test device by comparison to a new International Standard for thromboplastin

BACKGROUND

Whole blood point-of-care PT/INR test devices, e.g. CoaguChek XS, are calibrated by their manufacturers. In the Netherlands, each new lot of test strips for CoaguChek XS is validated by a group of anticoagulant clinics collaborating with a Coagulation Reference Laboratory. In 2017, a new International Standard for recombinant human thromboplastin (coded rTF/16) has been established by the World Health Organization.

AIM

To assess uncertainty of the validation procedure and the magnitude of the INR bias of a series of consecutive lots of test strips imported in the Netherlands.

METHODS

CoaguChek XS test strip INR results were compared to INRs determined with the new International Standard rTF/16. Comparisons were made with variable numbers of blood samples obtained from patients treated with vitamin K-antagonists. Relationships between CoaguChek XS and rTF/16 results were determined with orthogonal regression analysis. The relationships were used to assess bias and uncertainty of bias.

RESULTS

Average bias between CoaguChek XS test results and rTF/16 depends on the INR level. Overall, there was a trend of increasing bias and increasing uncertainty with increasing INR values. Along the sequence of 47 consecutive lots, a temporary fluctuation of bias was observed. At an INR level of 3.0 the average bias was less than 10% in all cases, but at an INR of 4.0 there were 5 lots with average bias between 10 and 15%.

CONCLUSION

Validation of test strips is useful to assess bias but depends on availability of fresh patients' samples and traceability to an accepted Reference Measurement System.

The effect of vitamin K on prothrombin time in critically ill patients: an observational registry study

Background

Previous studies have indicated that vitamin K deficiency is common in non-bleeding critically ill patients with slightly prolonged prothrombin time-international normalized ratio (PT-INR). It has never been investigated thoroughly whether the administration of vitamin K to these patients could affect their PT-INR. Therefore, the aim of this registry study was to evaluate changes in PT-INR in response to vitamin K in critically ill patients with PT-INR in the range of 1.3–1.9.

Methods

Patients admitted to a mixed 9-bed general intensive care unit at a University Hospital, between 2013 and 2019 (n = 4541) with a PT-INR between 1.3 and 1.9 at any time during the stay were identified. Patients who received vitamin K with appropriate sampling times for PT-INR and without exclusion criteria were matched with propensity score to patients from the same cohort who did not receive vitamin K (controls). PT-INR was measured at admission, within 12 h before vitamin K administration and 12–36 h following vitamin K administration. Exclusion criteria included pre-existing liver cirrhosis, any plasma or platelet transfusion, or > 1 unit red blood cell transfusion between PT-INR samplings.

Results

Propensity score matching resulted in two groups of patients with 129 patients in each group. PT-INR decreased in both groups (1.4 [1.3–1.4] in the vitamin K group and 1.4 [1.3–1.6] in the controls, p < 0.001 and p = 0.004, respectively). The decrease in PT-INR was slightly more pronounced in patients who received vitamin K (delta PT-INR − 0.10 [− 0.30 to − 0.10] in the vitamin K group and − 0.10 [− 0.20 to 0.10] in the controls, p = 0.01).

Conclusion

In critically ill patients with a PT-INR of 1.3–1.9, the administration of vitamin K resulted in a slightly larger decrease of PT-INR 12–36 h after administration compared to controls. Future studies should focus on identifying which patient populations may benefit most from vitamin K administration as well as whether vitamin K could be a better alternative than plasma or prothrombin complex concentrate to improve PT-INR before non-emergent invasive procedures.

Coagulation standards in healthy newborns and infants

BACKGROUND

The range of normal values for coagulation factors in the healthy newborn was described 30 years ago but since then the reagents, automated systems, and dosing techniques have changed considerably. For 30 years, several authors have tried to update the standards and references in children using updated reagents but the newborn and infant population in these studies has been quite small, limiting the findings. The aim of this study was to establish the normal coagulation standards in healthy newborns.

METHODS

We included all consecutive healthy newborns with pyloric stenosis presenting to our reference center over a period of 5 years. We calculated the reference ranges defined as mean±2 SD. Normality of distribution was checked graphically and by using the Shapiro-Wilk test. Correlations between two continuous variables were assessed using Spearman's rank coefficient correlation. Statistical testing was done at the two-tailed α-level of 0.05. Data were analyzed using the SAS software package, release 9.4 (SAS Institute, Cary, NC).

RESULTS

We included 112 healthy newborns and infants. The median age was 35.5 days (15.0-88.0), median weight was 4062g (2855-6040), and 90.2% were boys. Activated partial thromboplastin time (aPTT) and prothrombin time (PT) were not correlated with age (P=0.92 and P=0.21, respectively) or with weight (P=0.16 and P=0.90, respectively). The reference range was 28.6-46.2 s for aPTT, 0.91-1.49 for aPTT ratio, and 71.3-110.6 s for PT. Regarding fibrinogen (n=24), the median was 2.2g/L (1.2-3.2); the median for factor II was 67.0U/dL (51.0-130.0; n=20), and 101.5U/dL for factor V (68.0-233.0; n=20). Regarding factor VIII, the median was 75.0U/dL (45.0-152.0; n=25), 49.0U/dL for factor IX (32.0-96.0; n=25) and 53.0U/dL (29.0-112.0) for factor XI (n=23).

CONCLUSION

This study can help to establish standards for coagulation testing in this very specific population. Indeed, our study represents the largest newborn population in a recent investigation of PT and aPTT using updated reagents.

Effect of anticoagulant adjustment on prothrombin time test using two different PT reagents in patients with elevated hematocrit

The recommendations for adjustment of citrate volume in sample tubes with high hematocrit (Ht) are based on indirect studies of underfilled tubes or artificially constructed Ht values. The aim of this study was to evaluate the effect of citrate volume adjustment in sample tubes from patients with hematocrit >55% using two different prothrombin time (PT) tests.

METHODS

Paired citrate-adjusted and unadjusted blood specimens were obtained from 181 patients from the pulmonary hypertension ambulatory with high Ht values and on warfarin therapy. The samples were tested using recombinant human tissue factor (RTF) and reagents extracted from rabbit brain (HS Plus). The results are expressed as the international normalized ratio (INR). The correlation and percent change (% change) between sample pairs were calculated.

RESULTS

INR-RTF results from adjusted and unadjusted citrate blood specimens showed a strong correlation (R2 ​= ​0.8226, p ​< ​0.0001). The INR median was 2.25 (95% CI 2.10 to 2.41) for citrate-adjusted samples and was 2.22 (95% CI 2.06 to 2.38) for citrate-unadjusted samples. For samples with Ht >62%, the % change between sample pairs was >10%. Results using HS Plus showed a moderate correlation between citrate-adjusted and unadjusted samples (R2 ​= ​0.4267, p ​< ​0.0001). The INR median was 2.51 (95% CI 2.35 to 2.68) for citrate-adjusted samples and 3.45 (95% CI 3.11 to 3.80) for citrate-unadjusted samples. For samples with Ht>55%, the % change between sample pairs was higher than 10%.

CONCLUSION

Our data demonstrate that in patients with polycythemia on warfarin therapy, INR-RTF does not require anticoagulant adjustment for assessment of samples with Ht <62%.

Fully printed prothrombin time sensor for point-of-care testing

With an increasing number of patients relying on blood thinners to treat medical conditions, there is a rising need for rapid, low-cost, portable testing of blood coagulation time or prothrombin time (PT). Current methods for measuring PT require regular visits to outpatient clinics, which is cumbersome and time-consuming, decreasing patient quality of life. In this work, we developed a handheld point-of-care test (POCT) to measure PT using electrical transduction. Low-cost PT sensors were fully printed using an aerosol jet printer and conductive inks of Ag nanoparticles, Ag nanowires, and carbon nanotubes. Using benchtop control electronics to test this impedance-based biosensor, it was found that the capacitive nature of blood obscures the clotting response at frequencies below 10 kHz, leading to an optimized operating frequency of 15 kHz. When printed on polyimide, the PT sensor exhibited no variation in the measured clotting time, even when flexed to a 35 mm bend radius. In addition, consistent PT measurements for both chicken and human blood illustrate the versatility of these printed biosensors under disparate operating conditions, where chicken blood clots within 30 min and anticoagulated human blood clots within 20-100 s. Finally, a low-cost, handheld POCT was developed to measure PT for human blood, yielding 70% lower noise compared to measurement with a commercial potentiostat. This POCT with printed PT sensors has the potential to dramatically improve the quality of life for patients on blood thinners and, in the long term, could be incorporated into a fully flexible and wearable sensing platform.

Prolonged prothrombin time at admission predicts poor clinical outcome in COVID-19 patients

BACKGROUND

The prognostic value of coagulation disorder in coronavirus disease 2019 (COVID-19) patients should be demonstrated.

AIM

To investigate the abnormalities of coagulation parameters in the patients with COVID-19 and their prognostic values.

METHODS

Consecutive patients admitted in the isolation ward of Renmin Hospital of Wuhan University from January 31 to February 5, 2020 with confirmed COVID-19 were included. The primary outcomes were death and survival as of March 11. Demographics, vital signs, comorbidities and laboratory tests were collected and compared between those who died and survivors. Logistic regression analysis for prognostic factors was performed. Kaplan-Meier analysis was used to compare the estimated survival rate between patients with prolonged prothrombin time and normal prothrombin time.

RESULTS

The total number of patients with confirmed COVID-19 who were enrolled was 213. The median age was 62 years, and 95 patients (44.6%) were men. Fifty-one patients were critical (23.9%), 79 patients were severe (37.1%) and 83 patients were moderate (39%). As of March 11, 2020, 99 patients were discharged (46.5%), 79 patients (37.1%) stayed in the hospital and 35 patients (16.2%) died. Median time to death was 6 (4-8) d, while median hospital stay was 32 (22-36) d in survivors (P < 0.001). More men (P = 0.002) and elderly patients (P < 0.001) were found in the group of those who died. The respiration rate at admission was higher in the group of those who died (P < 0.001). The incidences of hypertension (P = 0.028), cerebrovascular disease (P < 0.001), chronic kidney disease (P = 0.02) and chronic obstructive pulmonary disease (P < 0.001) were higher in the group of those who died. Platelet count was decreased in the group of those who died (P = 0.002) whereas prothrombin time (P < 0.001), activated partial thromboplastin time (P = 0.033), concentration of D-dimer (P < 0.001) and fibrin degradation products (P < 0.001) were increased in the group of those who died. Prothrombin time [odds ratio (OR): 2.19, P = 0.004], respiration rate (OR: 1.223, P < 0.001), age (OR: 1.074, P < 0.001) and fibrin degradation products concentration (OR: 1.02, P = 0.014) were predictors of death. The survival rate was significantly lower in patients with prolonged prothrombin time compare to those with normal prothrombin time (P < 0.001).

CONCLUSION

Prothrombin time, concentration of fibrin degradation products, respiration rate and age were predictive factors for clinical outcomes of COVID-19 patients.

The relationship between coagulation disorders and the risk of bleeding in cirrhotic patients

INTRODUCTION AND OBJECTIVES

For long, bleeding in cirrhotic patients has been associated with acquired coagulation disorders. The aim of our study was to investigate the impact of acquired coagulation disorders on bleeding risk in cirrhotic patients.

MATERIALS AND METHODS

Blood samples were collected from 51 cirrhotic patients with (H+) or without (H-) bleeding events and 50 controls matched by age and sex. Thrombin generation was assessed as endogenous thrombin potential (ETP). Hemostatic balance was assessed by means of ratios of pro- to anticoagulant factors and by ETP ratio with/without protein C (PC) activator (ETP ratio).

RESULTS

Bleeding events occurred in 9 patients (17.6%). Compared with controls, VIII/anticoagulant factors, VII/PC and XII/PC were significantly higher in (H+) patients. No significant difference as regards all ratios across patient groups was detected. ETP ratio was significantly higher in (H+) patients than in controls (p=0.017). However, there was no significant difference between patient groups as regards ETP ratio.

CONCLUSION

Hemostatic balance is shifted toward a hypercoagulability state even in cirrhotic patients who experienced bleeding. These findings provide evidence against traditional concept of hemostasis-related bleeding tendency in cirrhotic patients.

Accidental chlorophacinone exposure of lactating ewes: Clinical follow-up and human health dietary implications

Anticoagulant rodenticides are widely used for rodent control in agricultural and urban settings. Their intense use can sometimes result in accidental exposure and even poisoning of livestock. Can milk, eggs or meat derived from such accidently exposed animals be consumed by humans? Data on the pharmacokinetics of chlorophacinone in milk of accidently exposed ewes were used to estimate the risk associated with its consumption. Three days after accidental ingestion, chlorophacinone was detected in plasma of 18 ewes, with concentrations exceeding 100 ng/mL in 11 animals. Chlorophacinone was detected in milk on day 2 post-exposure and remained quantifiable for at least 7 days in milk of these 11 ewes. Concentrations in milk were much lower than in plasma and decreased quickly (mean half-life of 2 days). This study demonstrated dose-dependent mammary transfer of ingested chlorophacinone. Variation in prothrombin time (PT) on Day 3 suggested that some of the ewes that ingested chlorophacinone may have been adversely affected, but PT did not facilitate estimation of the quantity of chlorophacinone consumed. Using safety factors described in the literature, consumption of dairy products derived from these ewes after a one-week withdrawal period would pose low risk to consumers.

Oxidized LDL induces procoagulant profiles by increasing lysophosphatidylcholine levels, lysophosphatidylethanolamine levels, and Lp-PLA2 activity in borderline hypercholesterolemia

BACKGROUND AND AIMS

The increased risk of cardiovascular disease under hypercholesterolemia is due to associations between oxidized low-density lipoprotein (ox-LDL) and lipoprotein-associated phospholipase A₂ (Lp-PLA₂) and between ox-LDL and coagulant profiles. We investigated the impact of different ox-LDL levels on coagulation time and plasma metabolomes in subjects with borderline hypercholesterolemia.

METHODS AND RESULTS

One hundred thirty-one subjects with borderline hypercholesterolemia (serum cholesterol ≥200 mg/dL) were divided into low ox-LDL (n = 66) and high ox-LDL (n = 65) groups. After adjusting for confounding factors, the high ox-LDL group exhibited a significantly decreased activated partial thromboplastin time (aPTT) and prothrombin time (PT) and increased Lp-PLA₂ activity. Compared to the low ox-LDL group, the high ox-LDL group exhibited significantly increased intensities of 17 lysophosphatidylcholines (lysoPCs) and 7 lysophosphatidylethanolamines (lysoPEs). Ox-LDL was inversely correlated with aPTT and PT and positively correlated with Lp-PLA₂ activity. Positive correlations were also found among ox-LDL, Lp-PLA₂ activity, lysoPCs, and lysoPEs. LysoPCs and lysoPEs were inversely correlated with PT and aPTT. The identified plasma metabolites, including amino acids, fatty acid amides, acylcarnitines, and lysophospholipids, were significantly upregulated in the high ox-LDL group.

CONCLUSION

High ox-LDL levels may be involved in the development of a procoagulant state in subjects with borderline hypercholesterolemia by increasing Lp-PLA₂ activity and lysoPC and lysoPE levels.

Pentraxin-3 is not related to disease severity in cirrhosis and hepatocellular carcinoma patients

The acute-phase protein pentraxin-3 (PTX3) is a component of the innate immune system. Inflammation and tissue injury increased PTX3 in the injured liver, and accordingly, circulating PTX3 was induced in patients with chronic liver diseases. In the present study, PTX3 protein was determined in systemic, hepatic, and portal vein plasma of patients with liver cirrhosis to assess a possible association between hepatic PTX3 release and extent of liver injury. However, PTX3 levels were not related to disease severity. Of note, portal PTX3 levels were higher than concentrations in the hepatic vein. PTX3 in the hepatic and portal veins was negatively correlated with factor V, antithrombin 3, and prothrombin time. PTX3 did neither correlate with C-reactive protein nor galectin-3 or resistin, whereby the latter two proteins are associated with hepatic injury. PTX3 levels were not changed in cirrhosis patients with ascites or varices and did not correlate with the hepatic venous pressure gradient. Likewise, serum PTX3 was not correlated with histological steatosis, inflammation, or fibrosis stage in patients with hepatocellular carcinoma (HCC). Moreover, PTX3 was not associated with tumor node metastasis classification in HCC. Above all, PTX3 increased in hepatic, portal, and systemic blood immediately after transjugular intrahepatic portosystemic shunt (TIPS). Higher PTX3 in portal than hepatic vein plasma and further increase after TIPS suggests that the liver eliminates PTX3 from the circulation. In summary, PTX3 is not of diagnostic value in cirrhosis and HCC patients.

Impact of Anticoagulation Intensity in Korean Patients with Atrial Fibrillation: Is It Different from Western Population?

BACKGROUND AND OBJECTIVES

Although anticoagulation with warfarin is recommended as an international normalized ratio (INR) of prothrombin time between 2.0 and 3.0 and mean time in the therapeutic range (TTR) ≥70%, little has been proven that universal criteria might be suitable in Korean atrial fibrillation (AF) patients.

METHODS

We analyzed 710 patients with non-valvular AF who took warfarin. INR value and clinical outcomes were assessed during 2-year follow-up. Intensity of anticoagulation was assessed as mean INR value and TTR according to target INR range. Primary net-clinical outcome was defined as the composite of new-onset stroke and major bleeding. Secondary net-clinical outcome was defined as the composite of new-onset stroke, major bleeding and death.

RESULTS

Thromboembolism was significantly decreased when mean INR was over 1.6. Major bleeding was significantly decreased when TTR was over 70% and mean INR was less than 2.6. Mean INR 1.6-2.6 significantly reduced thromboembolism (adjusted hazard ratio [HR], 0.40; 95% confidence interval [CI], 0.19-0.85), major bleeding (HR, 0.43; 95% CI, 0.23-0.81), primary (HR, 0.50; 95% CI, 0.29-0.84) and secondary (HR, 0.45; 95% CI, 0.28-0.74) net-clinical outcomes, whereas mean INR 2.0-3.0 did not. Simultaneous satisfaction of mean INR 1.6-2.6 and TTR ≥70% was associated with significant risk reduction of major bleeding, primary and secondary net-clinical outcomes.

CONCLUSIONS

Mean INR 1.6-2.6 was better than mean INR 2.0-3.0 for the prevention of thromboembolism and major bleeding. However, INR 1.6-2.6 and TTR ≥70% had similar clinical outcomes to INR 2.0-3.0 and TTR ≥70% in Korean patients with non-valvular AF.

Fulminant hepatitis and elevated levels of sIL-2R in thyroid storm

SUMMARY

We report the case of a 48-year-old man with thyroid storm associated with fulminant hepatitis and elevated levels of soluble interleukin-2 receptor (sIL-2R). Fatigue, low-grade fever, shortness of breath, and weight loss developed over several months. The patient was admitted to the hospital because of tachycardia-induced heart failure and liver dysfunction. Graves' disease with heart failure was diagnosed. He was treated with methimazole, inorganic iodide, and a β-blocker. On the day after admission, he became unconscious with a high fever and was transferred to the intensive care unit. Cardiogenic shock with atrial flutter was treated with intra-aortic balloon pumping and cardioversion. Hyperthyroidism decreased over 10 days, but hepatic failure developed. He was diagnosed with thyroid storm accompanied by fulminant hepatitis. Laboratory investigations revealed elevated levels of sIL-2R (9770 U/mL). The fulminant hepatitis was refractory to plasma exchange and plasma filtration with dialysis, and no donors for liver transplantation were available. He died of hemoperitoneum and gastrointestinal hemorrhage due to fulminant hepatitis 62 days after admission. Elevated circulating levels of sIL-2R might be a marker of poor prognosis in thyroid storm with fulminant hepatitis.

LEARNING POINTS

The prognosis of thyroid storm when fulminant hepatitis occurs is poor. Liver transplantation is the preferred treatment for fulminant hepatitis induced by thyroid storm refractory to plasma exchange. Elevated levels of soluble interleukin-2 receptor might be a marker of poor prognosis in patients with thyroid storm.

Prothrombin time, activated partial thromboplastin time and platelet counts of type II diabetes mellitus: a comparative study

Background

The incidence of cardiovascular disease due to thrombosis is 2-4 folds greater in diabetic patients. Prothrombin time, activated partial thromboplastin time and platelet count are hematological indices that give an insight into the coagulation status. Hence, this study aims to assess the coagulation status of type II diabetic patients.

Methods

A comparative cross-sectional study was conducted at Bahir Dar Felege Hiwot referral hospital, Northwest Ethiopia. A total of 40 treated type II diabetic, 40 untreated diabetics and 40 non-diabetic subjects were included. After taking informed consent, structured questionnaire was used to collect socio-demographic data. Following interview, 4 ml of blood was collected to determine PT, aPTT and platelet count of the three groups. The data were entered into SPSS version 20 and analyzed. One-way ANOVA was used to compare means of PT, aPTT and platelet count among the groups. A P value less than 0.05 was considered as statistically significant.

Results

The mean aPTT of non-diabetic, treated and untreated type II diabetic patient was 32.8 ± 4.12 s, 34.4 ± 5.3 s, and 25.42 ± 8.46 s, respectively. The proportion of untreated diabetic patients with normal PT, aPTT and platelet counts was 60.0%, 7.5 and 92.5%, respectively. There was a significant shortening of aPTT in untreated diabetic as compared to both treated and non-diabetic controls (P < 0.001).

Conclusions

Shortening of aPTT in untreated type II diabetic patients might be useful marker in patients with diabetes. Therefore, monitoring the aPTT in newly diagnosed diabetic patients is important.

Use of blood clotting assays to assess potential anticoagulant rodenticide exposure and effects in free-ranging birds of prey

Non-target wildlife, particularly birds of prey, are widely exposed to and acutely poisoned by anticoagulant rodenticides (ARs). An unresolved issue surrounding such exposure, however, is the potential for sublethal effects. In particular, the consequences of AR exposure and resulting coagulopathy on health and survival of unintentionally exposed animals, which often encounter a multitude of anthropogenic stressors, are understudied. In a wildlife rehabilitation setting, AR intoxication may be masked by more obvious injuries related to collision with vehicles or electrocution, thereby obfuscating proximate from ultimate cause of mortality. An assessment of coagulation function of admitted wildlife may provide a means of identifying animals exhibiting sublethal coagulopathy, and ultimately ensuring provision of appropriate and swift treatment. In conjunction with routine diagnostics for injury and disease, we performed two blood clotting assays (prothrombin time, Russell's viper venom time) affected by vitamin K-dependent coagulopathy of samples from six species of live raptors admitted to a rehabilitation facility. We also measured clotting time in pre-fledgling barn owl chicks (Tyto furcata) from 10 nest sites in Lower Mainland Canada. Prolonged clotting time or failure to form a clot altogether was observed in 23.0% of 61 sampled raptors admitted to the rehabilitation facility. This is a biologically significant proportion of individuals given the fortuitous and likely biased nature by which raptors are found and admitted to rehabilitation facilities. In contrast, there was little evidence of coagulopathy in 19 pre-fledgling barn owl chicks. The utility of avian coagulation tests for diagnosing AR exposure is promising, yet there remains a need to establish species specific reference values and standardize assay methodologies among testing facilities.

A novel scoring system based on hemostatic parameters predicts the prognosis of patients with advanced pancreatic cancer

OBJECTIVE

The aim of this study was to evaluate the prognostic value of pre-treatment plasma hemostatic parameters in patients with advanced pancreatic cancer.

METHODS

A total of 320 patients diagnosed with advanced pancreatic cancer between January 1, 2011 to December 31, 2015 were enrolled in this retrospective study. The prognostic significance of hemostatic parameters such as prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FBG), platelet count (PLT), mean platelet volume (MPV), plateletcrit (PCT), and platelet distribution width (PDW) was determined by univariate and multivariate Cox hazard models. Then, Kaplan-Meier methods and log-rank tests were performed to compare the survival of patients in different risk groups.

RESULT

Univariate and multivariate analyses showed that prolonged PT, high FBG, and high MPV were independent prognostic factors for poor overall survival (PT > 11.3 s, HR = 1.46, 95%CI = 1.10-1.94, p = 0.009; FBG>2.5 g/L, HR = 1.41, 95%CI = 1.08-1.84, p = 0.011; MPV>12.2 fL, HR = 1.52, 95%CI = 1.13-2.04, p = 0.005). Moreover, all the patients were stratified into three groups by a scoring system based on these three hemostatic markers. The median survival time of the three groups was 8.8 months, 6.3 months and 4.3 months (P < 0.001).

CONCLUSION

PT, FBG and MPV were independent prognostic factors in advanced pancreatic cancer. A novel scoring system based on these hemostatic parameters could be used to predict the survival of patients with advanced pancreatic cancer.

Prolonged partial thromboplastin time: To mix or not to mix - is that the question?

Routine mixing studies are frequently used to evaluate patients presenting with prolonged partial thromboplastin times (PTT) and/or prothrombin times (PT). Unfortunately, mixing studies have a number of inherent limitations including lack of standardization in terms of what defines normal pooled plasma (NPP), the processing of a patient's plasma for platelet removal (platelet poor plasma versus platelet-free plasma), performance of appropriate controls, conducting an incubation step to evaluate for a time and temperature dependent inhibitor, and finally interpretation of test results. Moreover, misinterpretation of study results can lead to a delayed or incorrect diagnosis or worse, inappropriate treatment. Within this manuscript, we present four cases illustrating the shortcomings associated with inappropriate utilization and interpretation of routine mixing studies; and present practical steps for managing abnormal PT or PTT results.

Biology of Coagulation and Coagulopathy in Neurologic Surgery

Hemostasis is a cell-based process that is regulated in a tissue-specific manner by the differential expression of procoagulant and anticoagulant factors on endothelial cells from different sites throughout the vasculature. The central nervous system, in particular, exhibits unique mechanisms of hemostatic regulation that favor increased activity of the tissue factor pathway. This results in an unusually high degree of protection against hemorrhage, at the potential expense of increased thrombotic risk. Unfortunately, standard laboratory assays, including the PT and aPTT, do not accurately reflect the complexity of hemostasis in vivo; therefore, they cannot predict the risk of bleeding or thrombosis.

Interaction between warfarin and short-term intravenous amiodarone in intensive care unit patients after cardiac surgery

Background

Amiodarone and warfarin are sometimes administered immediately after cardiac surgery. Although the interaction between long-term oral amiodarone and warfarin has been reported, the interaction between warfarin and short-term intravenous amiodarone has not been reported. In this study, we investigated the effect of short-term intravenous amiodarone on the anticoagulant effect of warfarin in patients who underwent cardiac surgery.

Methods

We retrospectively reviewed the medical records of 11 patients who received oral warfarin before and after cardiac surgery, and loading doses of 125–150 mg or a 750 mg continuous infusion of amiodarone, or both in the intensive care unit (ICU) within 5 days after the surgery between July 2011 and January 2017. The prothrombin time-international normalized ratio (PT-INR)/daily warfarin dose (PT-INR/dose) was used as an indicator of anticoagulant effect. The values before surgery were considered as the baseline.

Results

The PT-INR and PT-INR/dose values were elevated in 7 and 10 patients, respectively, after amiodarone administration. The mean PT-INR values were not significantly different before and after amiodarone administration (2.13 ± 0.58 vs 2.29 ± 0.50, respectively, p = 0.643). In contrast, the mean PT-INR/dose values were significantly elevated after the administration of amiodarone (0.93 ± 0.46 vs 1.54 ± 0.63, respectively, p = 0.002).

Conclusions

Short-term intravenous amiodarone enhanced the anticoagulant effect of warfarin in patients admitted to the ICU after cardiac surgery. We suggest that the dose of warfarin should be carefully adjusted for a few days after cardiac surgery if intravenous amiodarone is coadministered.

An analysis on distribution and inter-relationships of biomarkers under rivaroxaban in Japanese patients with non-valvular atrial fibrillation (CVI ARO 1)

Prothrombin time (PT) has been widely used for measuring anticoagulation intensity under rivaroxaban therapy, but precise information has not been well established yet. Consecutive 96 non-valvular atrial fibrillation (NVAF) under rivaroxaban between Jan/June, 2015 were recruited. Serum concentration (SC) and PT with 5 representative reagents available in Japan (Neoplastin Plus®, Thromborel S®, Thrombocheck PT®, Thrombocheck PT Plus®, and Recombiplastin®) at 2-4 hours after (peak) and before intake of rivaroxaban (trough) were measured at outpatient clinic in the cardiovascular institute (CVI ARO study 1). Nonlinear mixed-effects modelling was used to model the population pharmacokinetics and pharmacodynamics of rivaroxaban. An oral one-compartment model was employed to describe the population pharmacokinetics of rivaroxaban. The pharmacokinetics of rivaroxaban were affected by creatinine clearance, alanine aminotransferase, and use of CYP3A4 or P-gp inhibitors. PTs with 5 reagents were predicted by pharmacodinamic models with SC, hematocrit, serum albumin, and age, with medium predicting ability (highest/lowest R2 = 0.746/0.658 in Recombiplastin/Thromborel S, respectively). This population analysis in NVAF patients under rivaroxaban therapy demonstrated that pharmacokinetics of rivaroxaban was described by an oral one-compartment model with expected covariates, and can be assessed by PT with available reagents in Japan with medium predicting ability.

The clinical impact of edoxaban for the patients with postoperative anemia after total hip arthroplasty

BACKGROUND

Postoperative anemia is a common complication after total hip arthroplasty (THA). However, the effect of edoxaban on postoperative anemia after THA remains unclear. Here, we retrospectively evaluated the clinical assessment of postoperative anemia and the associated changes of coagulation parameters in patients undergoing thromboprophylaxis with edoxaban compared with fondaparinux as a conventional anticoagulant thromboprophylactic agent after THA.

METHODS

One hundred and forty-nine patients who underwent THA from July 2010 to June 2012 were divided into two groups, according to whether they were operated on before or after the approval of edoxaban: the fondaparinux group (Group F: 86 patients) and the edoxaban group (Group E: 63 patients). The frequency of postoperative anemia and blood coagulation values were investigated.

RESULTS

Postoperative anemia developed more frequently in Group E than in Group F after surgery. However, the degree of postoperative anemia showed no significant difference between the groups. Meanwhile, prothrombin time (PT), prothrombin time-international normalized ratio (PT-INR), and activated partial thromboplastin time were markedly higher in patients with edoxaban-associated postoperative anemia, which showed an increased potential to predict the occurrence of postoperative anemia. Additionally, both PT and PT-INR in Group E were also correlated with the volume of estimated blood loss.

CONCLUSION

The frequency of postoperative anemia was increased in patients treated with edoxaban, compared to fondaparinux, after THA. Edoxaban thromboprophylaxis might, therefore, require more careful monitoring to prevent postoperative anemia. Additionally, particular prolongation of PT and PT-INR induced by edoxaban treatment might predict postoperative anemia.