Oral anticoagulants: mechanism of action, clinical effectiveness, and optimal therapeutic range

Ferrocenyl Azoles: Versatile N-Containing Heterocycles and their Anticancer Activities

The medicinal chemistry of ferrocene has gained its momentum after the discovery of biological activities of ferrocifen and ferroquine. These ferrocenyl drugs have been designed by replacing the aromatic moiety of the organic drugs, tamoxifen and chloroquine respectively, with a ferrocenyl unit. The promising biological activities of these ferrocenyl drugs have paved a path to explore the medicinal applications of several ferrocenyl conjugates. In these conjugates, the ferrocenyl moiety has played a vital role in enhancing or imparting the anticancer activity to the molecule. The ferrocenyl conjugates induce the cytotoxicity by generating reactive oxygen species and thereby damaging the DNA. In medicinal chemistry, the five membered nitrogen heterocycles (azoles) play a significant role due to their rigid ring structure and hydrogen bonding ability with the biomolecules. Several potent drug candidates with azole groups have been in use as chemotherapeutics. Considering the importance of ferrocenyl moiety and azole groups, several ferrocenyl azole conjugates have been synthesized and screened for their biological activities. Hence, in the view of a wide scope in the development of potent drugs based on ferrocenyl azole conjugates, herein we present the details of synthesis and the anticancer activities of ferrocenyl compounds bearing azole groups such as imidazole, triazoles, thiazole and isoxazoles.

Effectiveness of Anticoagulants in Reducing Stroke Risk Among Patients With Atrial Fibrillation

Atrial fibrillation (AF) is a type of cardiac arrhythmia causing shortness of breath, lightheadedness, and palpitations. It may go unrecognized and asymptomatic among many patients. AF is not a potentially fatal arrhythmia; its hemodynamic, structural, and hemocoagulative effects have a significant impact on the standard of life, which can lead to various complications such as stroke. A stroke caused by AF leads to additional burdens on both patients and the global economy. Patients with AF can prevent strokes with oral anticoagulants; however, ensuring diligent adherence to medication is crucial for maximizing treatment efficacy. Since they have a lighter treatment load than warfarin, non-vitamin K antagonist oral anticoagulants (NOACs) are also recommended with better hope for medication adherence. Various anticoagulants such as warfarin and ximelagatran, among many more, are prescribed to patients who have the potential to reduce the incidence of stroke as well as alleviate their likelihood of developing other thromboembolic events that can decrease their quality of life. Economic and psychological burdens associated with diminished functionality can be prevented by anticoagulant therapy among AF patients, therefore reducing their economic and social burden. This is due to the negative association between stroke among AF patients and anticoagulation consumption.

Bioactivity and toxicity of coumarins from African medicinal plants

Introduction: Coumarins are naturally occuring metabolites from plants and a few micro-organisms. They have been widely used in the food and drug industry in their natural or synthetic forms. Numerous coumarins possess several biological activities such as anti-inflammatory, anti-ulcers, anti-tumour, anti-microbial, anti-coagulant. The aim of this study was to assess the bioactivity, and toxicity of coumarins from African medicinal plants. Methods: We searched online databases and search engines such as PubMed, Google Scholar and Web of Science for key terms such as coumarins, toxicity, bioavailability, bioactivity with appropriate Boolean operators. Only full-length research articles published in English between 1956 to 2023 were reviewed. Results: We recorded 22 coumarins from 15 plant species from Africa. Most of the plant species (33%) were from North Africa. These were followed by East Africa at 21%, then West, and Central Africa at 18.2% each. Most of the coumarins (21.3%) were isolated from the entire plant and the leaves (19.1%) and most of them (46.7%) had some antimicrobial activity. Five coumarins viz osthole, pseudocordatolide C & calanolide, chartreusin and esculetin had either antitumor or anticancer activity. Six coumarins had varying levels and types of toxicity ranging from inhibiting blood clotting as anticoagulants, to cytotoxic effects, causing hyperventilation, tremor, & photophobia, pulmonary haemorrhage, carcinogenic activity, severe neurotoxicity, hepato- and phototoxicity. Conclusion: Several African medicinal plants are sources of various coumarins that possess several biological activities as well as toxicities. This calls for more research into their safety and efficacy because of their wide spread applications as therapeutic agents.

New insights into the role of VKORC1 polymorphisms for optimal warfarin dose selection in Caribbean Hispanic patients through an external validation of a population PK/PD model

Warfarin, an oral anticoagulant, has been used for decades to prevent thromboembolic events. The complex interplay between CYP2C9 and VKORC1 genotypes on warfarin PK and PD properties is not fully understood in special sub-groups of patients. This study aimed to externally validate a population pharmacokinetic/pharmacodynamic (PK/PD) model for the effect of warfarin on international normalized ratio (INR) and to evaluate optimal dosing strategies based on the selected covariates in Caribbean Hispanic patients. INR, and CYP2C9 and VKORC1 genotypes from 138 patients were used to develop a population PK/PD model in NONMEM. The structural definition of a previously published PD model for INR was implemented. A numerical evaluation of the parameter-covariate relationship was performed. Simulations were conducted to determine optimal dosing strategies for each genotype combinations, focusing on achieving therapeutic INR levels. Findings revealed elevated IC50 for G/G, G/A, and A/A VKORC1 haplotypes (11.76, 10.49, and 9.22 mg/L, respectively), in this population compared to previous reports. The model-guided dosing analysis recommended daily warfarin doses of 3-5 mg for most genotypes to maintain desired INR levels, although subjects with combination of CYP2C9 and VKORC1 genotypes * 2/* 2-, * 2/* 3- and * 2/* 5-A/A would require only 1 mg daily. This research underscores the potential of population PK/PD modeling to inform personalized warfarin dosing in populations typically underrepresented in clinical studies, potentially leading to improved treatment outcomes and patient safety. By integrating genetic factors and clinical data, this approach could pave the way for more effective and tailored anticoagulation therapy in diverse patient groups.

Effect of MEF2A and SLC22A3-LPAL2-LPA gene polymorphisms on warfarin sensitivity and responsiveness in Jordanian cardiovascular patients

AIMS

This study aims to investigate the influence of MEF2A and SLC22A3-LPAL2-LPA polymorphisms on cardiovascular disease susceptibility and responsiveness to warfarin medication in Jordanian patients, during the initiation and maintenance phases of treatment.

BACKGROUNDS

Several candidate genes have been reported to be involved in warfarin metabolism and studying such genes may help in finding an accurate way to determine the needed warfarin dose to lower the risk of adverse drug effects, resulting in more safe anticoagulant therapy.

METHODS

The study population included 212 cardiovascular patients and 213 healthy controls. Genotyping of MEF2A and SLC22A3-LPAL2-LPA polymorphisms was conducted to examine their effects on warfarin efficiency and cardiovascular disease susceptibility using PCR-based methods.

RESULTS

One SNP (SLC22A3-LPAL2-LPA rs10455872) has been associated with cardiovascular disease in the Jordanian population, whereas the other SNPs in the MEF2A gene and SLC22A3-LPAL2-LPA gene cluster did not have any significant differences between cardiovascular patients and healthy individuals. Moreover, SLC22A3-LPAL2-LPA rs10455872 was correlated with moderate warfarin sensitivity, the other SNPs examined in the current study have not shown any significant associations with warfarin sensitivity and responsiveness.

CONCLUSION

Our data refer to a lack of correlation between the MEF2A polymorphism and the efficacy of warfarin treatment in both phases of treatment, the initiation, and maintenance phases. However, only rs10455872 SNP was associated with sensitivity to warfarin during the initiation phase. Furthermore, rs3125050 has been found to be associated with the international normalized number treatment outcomes in the maintenance phase.

Identifying and understanding the care pathway of patients with atrial fibrillation in Brazil and the impact of the COVID-19 pandemic: A mixed-methods study

BACKGROUND

Atrial fibrillation (AF) is a major risk factor for stroke. To enable improvements to AF diagnosis and follow-up care, understanding current patient pathways and barriers to optimal care are essential. We investigated the patient care pathways and their drivers, and the impact of the COVID-19 pandemic on patient pathways in a middle-income country setting, Brazil.

METHODS

This mixed-methods study in São Paulo, included adults (≥18y) with AF from 13 primary/secondary healthcare facilities. Surveys using baseline, follow-up (administered ≥two months after baseline) and COVID-19 questionnaires (quantitative), and three focus group discussions (FGDs) were conducted. Minimum sample size for the quantitative component was 236 and we aimed to reach saturation with at least three FGDs for the qualitative component. Descriptive statistics were used for quantitative data and a content analysis was used for qualitative data to identify themes related to AF diagnosis and follow-up care.

RESULTS

267 participants completed the baseline questionnaire: 25% were diagnosed in primary care, 65% in an emergency or inpatient department. At follow-up (n = 259), 31% visited more than one facility for AF care, and 7% had no follow-up. Intervals between international normalised ratio (INR) tests were increased during the pandemic, and the number of healthcare visits and availability of medication were reduced. Seventeen patients participated in three FGDs and revealed that AF diagnosis often occurred following a medical emergency and patients often delay care-seeking due to misconceptions about AF symptoms. Long waiting times, doctor/patient interactions and health system factors, such as doctor availability and the referral system, influence where participants visited for follow-up care.

CONCLUSIONS

Lack of public awareness and underdeveloped primary healthcare lead to delayed diagnosis, which impacts clinical outcomes and excess patient and healthcare system costs. Health system, care-provider, and pandemic factors disrupt timely and effective continuity of care.

Drug-microbiota interactions: an emerging priority for precision medicine

Individual variability in drug response (IVDR) can be a major cause of adverse drug reactions (ADRs) and prolonged therapy, resulting in a substantial health and economic burden. Despite extensive research in pharmacogenomics regarding the impact of individual genetic background on pharmacokinetics (PK) and pharmacodynamics (PD), genetic diversity explains only a limited proportion of IVDR. The role of gut microbiota, also known as the second genome, and its metabolites in modulating therapeutic outcomes in human diseases have been highlighted by recent studies. Consequently, the burgeoning field of pharmacomicrobiomics aims to explore the correlation between microbiota variation and IVDR or ADRs. This review presents an up-to-date overview of the intricate interactions between gut microbiota and classical therapeutic agents for human systemic diseases, including cancer, cardiovascular diseases (CVDs), endocrine diseases, and others. We summarise how microbiota, directly and indirectly, modify the absorption, distribution, metabolism, and excretion (ADME) of drugs. Conversely, drugs can also modulate the composition and function of gut microbiota, leading to changes in microbial metabolism and immune response. We also discuss the practical challenges, strategies, and opportunities in this field, emphasizing the critical need to develop an innovative approach to multi-omics, integrate various data types, including human and microbiota genomic data, as well as translate lab data into clinical practice. To sum up, pharmacomicrobiomics represents a promising avenue to address IVDR and improve patient outcomes, and further research in this field is imperative to unlock its full potential for precision medicine.

Wounds resulting from non-malignant haematological disease: a case series

A proactive and systemic approach is imperative to preventing wounds due to disorders of non-malignant haematologic disease. Here, the authors provide several examples of patients with either a known history or acute diagnosis of a coagulation disorder with the aim of reviewing potential cutaneous injuries as well as diagnosis and treatment. A description of the wound and treatment course along with recommendations where appropriate are presented. The article serves as a general review for health professionals who may encounter patients with this disorder and who are involved in treatment decisions. After reviewing the article, the practitioner will be able to identify cutaneous injuries that may be secondary to an underlying haematological disorder, review the diagnosis and treatment recommended, and understand the need for a multidisciplinary approach to patient care.

Anticoagulation decision-making before non-cardiac surgery in patients with mechanical heart valve: A retrospective study

Objective

To clarify the timing of warfarin discontinuation at different ranges of INR. Improve anticoagulation management in non-cardiac surgical patients with MHV.

Design

This is a single-center retrospective observational study.

Setting

and participants This study used data from the Hospital Information System, and the Surgery and Anesthesia Information System of the Second Affiliated Hospital of Army Military Medical University. Participants included 121 adult patients with MHV who underwent non-cardiac surgery from 2012 to 2021.

Results

Overall, 121 patients with MHV (15 aortic valve only, 56 mitral valve only, and 50 with multiple valves) underwent non-cardiac surgery. When the duration of warfarin discontinuation was ≤ 3 days, 3-5 days, and≥5 days, the INR was 1.45, 1.15, and 1.09, respectively. Bleeding between INR ≤1.2 and INR >1.2 groups was not statistically significant using Student's t-test (95% CI -0.57, 0.14 P = 0.24). Multivariate regression analysis revealed that Intraoperative bleeding volume correlated with preoperative albumin levels (OR = 0.68，95% CI 0.49, 0.89).

Conclusions

When need preoperative INR is less than 1.5 in patients with MHV undergoing non-cardiac surgery, preoperative warfarin discontinuation for 3 days is sufficient. If INR less than 1.2, preoperative warfarin discontinuation for 3-5 days is appropriate. And in patients with MHV underwent abdominal surgery, intraoperative bleeding is not significant reduced by lower INR after preoperative warfarin discontinuation. Furthermore, the effect of albumin levels on coagulation function cannot be ignored in patients with MHV.

Strengths and limitations

This study was derived from real-world clinical data. It's a retrospectively study to describe the INR changed according to the duration of warfarin discontinuation in patients with MHV and compared intraoperation of bleeding volume between INR>1.2 and INR ≤ 1.2after warfarin discontinuation. To clarify the timing of warfarin discontinuation at different ranges of INR. Improve anticoagulation management in non-cardiac surgical patients with MHV, while providing clinicians with a reference for preoperative warfarin adjustment. This study does have a few limitations. The number of cases is small because patients undergoing repeat noncardiac surgery after heart valve surgery are a special case population. And the patients were not followed up after non-cardiac surgery. The impact of changes in INR on postoperative complications could not be assessed in patients with MHV.

Computational analysis of missense variant CYP4F2*3 (V433M) in association with human CYP4F2 dysfunction: a functional and structural impact

BACKGROUND

Cytochrome P450 4F2 (CYP4F2) enzyme is a member of the CYP4 family responsible for the metabolism of fatty acids, therapeutic drugs, and signaling molecules such as arachidonic acid, tocopherols, and vitamin K. Several reports have demonstrated that the missense variant CYP4F2*3 (V433M) causes decreased activity of CYP4F2 and inter-individual variations in warfarin dose in different ethnic groups. However, the molecular pathogenicity mechanism of missense V433M in CYP4F2 at the atomic level has not yet been completely elucidated.

METHODS AND RESULTS

In the current study, we evaluated the effect of the V433M substitution on CYP4F2 using 14 different bioinformatics tools. Further molecular dynamics (MD) simulations were performed to assess the impact of the V433M mutation on the CYP4F2 protein structure, stability, and dynamics. In addition, molecular docking was used to illustrate the effect of V433M on its interaction with vitamin K1. Based on our results, the CYP4F2*3 variant was a damaging amino acid substitution with a destabilizing nature. The simulation results showed that missense V433M affects the dynamics and stability of CYP4F2 by reducing its compactness and stability, which means that it tends to change the overall structural conformation and flexibility of CYP4F2. The docking results showed that the CYP4F2*3 variant decreased the binding affinity between vitamin K1 and CYP4F2, which reduced the activity of CYP4F2*3 compared to native CYP4F2.

CONCLUSIONS

This study determined the molecular pathogenicity mechanism of the CYP4F2*3 variant on the human CYP4F2 protein and provided new information for understanding the structure-function relationship of CYP4F2 and other CYP4 enzymes. These findings will aid in the development of effective drugs and treatment options.

In vitro fermentation of heparin by the human gut microbiota: Changes in the microbiota community and metabolic functions

Levels of its utilization suggest that the host glycosaminoglycan heparin is an important carbohydrate in the human gut microbiota. However, the interaction between heparin and the gut microbiota is not well understood. In this study, an in vitro fermentation system combined with microbiome and metabolome technologies was used to study the interaction between heparin and the gut microbiota. Interestingly, we found that heparin can be used by the gut microbiota, which produce large amounts of short chain fatty acids leading to a decrease in pH. In addition, the addition of heparin increased the relative abundance of Bacteroides and Bifidobacterium and decreased the relative abundance of Escherichia-Shigella. Correlation analysis of the microbiome and metabolome revealed that the catabolism of heparin was accompanied by the biosynthesis of bile acids and tryptophan metabolism. Overall, this study provides new evidence on the role of heparin as a stable carbon source for the gut microbiota and forms a strong basis for the use of heparin to condition the gut microbiota.

Potential Association of Holidays on Internationalized Normalized Ratio in Warfarin-Users at a Multidisciplinary Clinic

Background

Warfarin is approved by the United States Food and Drug Administration for numerous clinical indications. The effectiveness of warfarin is highly dependent on the time-in-therapeutic range based on the international normalized ratio (INR) goal, which may be altered by changes in diet, alcohol intake, concomitant drugs, and travel, all of which are prevalent during the holidays. At this time, there are no published studies assessing the impact of holidays on INR in warfarin-users.

Methods

A retrospective chart review was conducted on all adult patients taking warfarin and managed at a multidisciplinary clinic. Patients were included if they were taking warfarin at home regardless of indication for anticoagulation. The INR pre- and post-holiday was assessed.

Results

Of a total of 92 patients, the mean age was 71.5 ± 14.3 years, and most patients were on warfarin with an INR goal of 2 - 3 (89%). There were significant differences in INR before and after Independence Day (2.55 vs. 2.81, P = 0.043) and Columbus Day (2.39 vs. 2.82, P < 0.001). The remaining holidays showed no significant differences in INR before and after each respective holiday.

Conclusions

There may be factors related to Independence and Columbus Day that are increasing the level of anticoagulation in warfarin-users. Although the mean post-holiday INR values, in essence, maintained within the typical target of 2 - 3, our study underscores the specialized care that is warranted in higher risk patients to prevent a continued increase in INR and subsequent toxicities. We hope our results would be hypothesis-generating and aid in the development of larger, prospective evaluations to validate the findings of our present study.

Bleeding complications in patients on warfarin undergoing joint injection/aspiration: systematic review and meta-analysis

Steroid injections in joints are commonly administered for the management of inflammatory or degenerative conditions. There is substantial controversy as to whether to continue warfarin when undertaking joint injection or aspiration. To assess the rate of bleeding complications in patients on warfarin undergoing joint injection/aspiration. Systematic review and meta-analysis. A literature search of 3 online databases was conducted by 2 reviewers using the Cochrane methodology for systematic reviews. Eligibility criteria were any study that reported bleeding complication rates in adult patients on warfarin undergoing a joint injection/aspiration whilst taking warfarin anticoagulation. Studies reporting on less than 5 patients were excluded. Meta-analysis was conducted using a random effects model. The search of databases resulted in a total of 1547 articles. After screening, 8 articles were deemed suitable for inclusion in the analysis, involving 871 injection/aspiration procedures. There were only 5 reported cases of bleeding. On meta-analysis the estimated bleeding complication rate was 1.5% (95% CI 0.5-4.5%). This meta-analysis shows that it is safe to perform joint injection and aspiration in patients on warfarin without routine prior testing of INR. Level of evidence: Level 4.

Efficacy and Safety of Renal Function on Edoxaban Versus Warfarin for Atrial Fibrillation: A Systematic Review and Meta-Analysis

Background: Edoxaban is a novel oral anticoagulant which may decrease the risk of stroke and systemic embolism in patients suffering from atrial fibrillation (AF). However, the decreased efficacy of edoxaban versus warfarin for the avoidance of stroke and systemic embolism in AF with creatinine clearance (CrCl) > 95 mL/min has been reported. The purpose of this meta-analysis is to further clarify the safety (major bleeding) and efficacy (stroke or systemic embolism) of edoxaban for AF patients with various CrCl. Methods: A systematic search of studies on edoxaban and warfarin in AF patients related to renal function was conducted in PubMed, Medline, Web of Science databases, EBSCO, Embase, and the Cochrane Central Register of Controlled Trials. In this meta-analysis (protocol number: PROSPERO CRD 42021245512), we included studies that provide specific data on three outcomes: ischemic stroke or systemic embolism (S/SE), bleeding, and all-cause mortality. Results: This meta-analysis enrolled two randomized controlled trials (RCTs) studies and two retrospective studies that enrolled 28,065 patients. According to CrCl, subjects are divided into three groups (CrCl 30−50 mL/min, CrCl 50−95 mL/min, CrCl > 95 mL/min). In AF patients with CrCl 30−50 mL/min, edoxaban 30 mg daily is similar to warfarin in the prevention of ischemic S/SE and all-cause mortality, resulting in lower bleeding rate and better net clinical outcome (ischemic S/SE: hazard ratio (HR), 0.85, 95% confidence interval (CI), 0.19−1.87; all-cause mortality: HR, 0.65, 95% CI, 0.35−1.19; bleeding: HR, 0.75, 95% CI, 0.60−0.93; net clinical outcome: HR, 0.75, 95% CI, 0.63−0.90). In the group of CrCl 50−95 mL/min, the net clinical outcome was more favorable with edoxaban 60 mg daily than warfarin (HR, 0.81, 95% CI: 0.68−0.96), and there was no significant difference between edoxaban 60 mg daily and warfarin in terms of prevention of bleeding, ischemic S/SE, and all-cause mortality. For AF patients with CrCl > 95 mL/min, there was a statistically significant difference in lower bleeding rate between edoxaban 60 mg daily and warfarin (bleeding: HR: 0.70, 95% CI: 0.58−0.84). There was no differential safety in ischemic S/SE, all-cause mortality, and net clinical outcome. Conclusion: Overall, edoxaban was superior to warfarin in terms of net clinical outcome in various groups of CrCl with AF patients. Although there was no significant difference in net clinical outcome between edoxaban and warfarin for AF patients with CrCl > 95 mL/min, edoxaban is not inferior to warfarin in safety and effectiveness in the various levels of CrCl. Edoxaban may be a more effective and safe treatment than warfarin for patients with chronic kidney disease (CKD) who require anticoagulation. More high-quality and long-term clinical research are needed to further estimate the effects of edoxaban.

Interference in point-of-care international normalized ratio monitoring in patients with lupus anticoagulant is correlated with anti-β2-glycoprotein I antibody titers

Background

Patients with antiphospholipid syndrome (APS) receive anticoagulant therapy with vitamin K antagonists (VKAs) to prevent recurrent thrombosis. VKA treatment requires strict monitoring with an international normalized ratio (INR). It is known that lupus anticoagulants (LAs) can lead to elevated INR results with point-of-care-testing (POCT) devices, which could result in inadequate adaptation of anticoagulant therapy.

Objective

To determine discrepancies between POCT-INR and laboratory-INR in patients who are LA-positive on VKA therapy.

Methods

Paired INR testing was performed with 1 POCT device (CoaguChek XS) and 2 laboratory assays (Owren and Quick method) in 33 patients with LA-positive APS on VKA in a single-center cross-sectional study. Patients were tested for anti-β2-glycoprotein I, anticardiolipin, and antiphosphatidylserine/prothrombin immunoglobulin (Ig) G and IgM antibodies. Agreement between assays was evaluated with Spearman's correlation, Lin's correlation coefficient, and Bland-Altman plots. Agreement limits were considered satisfactory if differences were ≤20% as determined by the Clinical and Laboratory Standards Institute.

Results

We found poor agreement between POCT-INR and laboratory-INR based on Lin's concordance correlation coefficient (ρ_c) of 0.42 (95% CI, 0.26-0.55) between POCT-INR and Owren-INR, a ρ_c of 0.64 (95% CI, 0.47-0.76) between POCT-INR and Quick-INR, and a ρ_c of 0.77 (95% CI, 0.64-0.85) between Quick-INR and Owren-INR. High anti-β2-glycoprotein I IgG antibody titers correlated with INR disagreement between POCT-INR and laboratory-INR.

Conclusion

There is a disagreement between INR values measured with the CoaguChek XS and laboratory-INR in a proportion of patients with LA. Consequently, laboratory-INR monitoring should be preferred over POCT-INR monitoring in patients with LA-positive APS, especially in patients with high anti-β2-glycoprotein IgG antibody titers.

Reduced Time to Procedure for Gastrointestinal Bleeding After Warfarin Reversal With Four-Factor Complex Concentrate as Compared to Plasma

Background

Bleeding is a serious adverse effect of vitamin K antagonists (VKAs). Anticoagulation reversal is required in some acute cases. This is usually accomplished by plasma transfusion or four-factor prothrombin complex concentrate (4F-PCC). The aim of this study was to gain insight into the clinical course of patients with gastrointestinal (GI) bleeding who require VKA reversal.

Methods

Medical records were collected from two centers from patients who presented to the emergency department (ED) for GI bleeding and received 4F-PCC or plasma for VKA reversal between January 2015 and December 2020. ED, hospital, intensive care unit (ICU) length of stay (LOS) as well as time from admission to GI procedure were determined.

Results

4F-PCC patients (n = 49) as compared to plasma (n = 63) patients were found to have a greater number of comorbidities (average of 4.2 vs. 2.7 comorbidities/patient) and more ICU admissions (47% vs. 21%). Time to GI procedure was significantly decreased in the 4F-PCC group (median (interquartile range (IQR)) 19.47 (9.23 - 30.25) vs. 27.88 (21.38 - 45.00) h; P = 0.01). When adjusting for comorbidities, differences in time to GI procedures were also significant in favor of 4F-PCC regardless of any comorbidities (P = 0.014), in atrial fibrillation (P = 0.045) and in hypertension (P = 0.02). The 4F-PCC patients had shorter LOS in the ED and ICU.

Conclusions

Our study demonstrated that compared to plasma, 4F-PCC was utilized in more acutely ill patients with higher rates of comorbidities and ICU admission. Nevertheless, the patients who received 4F-PCC had faster access to GI procedure and shorter ED and ICU LOS.

Caryopteris odorata and its metabolite coumarin attenuate characteristic features of cardiometabolic syndrome in high-refined carbohydrate-high fat-cholesterol-loaded feed-fed diet rats

Caryopteris odorata (D. Don) B.L. Robinson (Verbenaceae family) is an aromaric shrub traditionally used to treat diabetes and related pathologies (diabetic foot ulcer), cancer/tumors, wound healing, and inflammation. It is enriched with flavonoids and phenolics like coumarins, quercetin, gallic acid, coumaric acid, stigmasterol, α-tocopherol, and iridoids. C. odorata has been reported as having α-glucosidase, anti-inflammatory, and anti-oxidant properties. Its effectiveness in preventing cardiometabolic syndrome has not yet been assessed. This study aims to investigate the potential efficacy of C. odorata and coumarin for characteristic features of cardiometabolic syndrome (CMS), including obesity, dyslipidemia, hyperglycemia, insulin resistance, and hypertension by using high-refined carbohydrate-high fat-cholesterol (HRCHFC)-loaded feed-fed rats. Chronic administration of C. odorata and coumarin for 6 weeks revealed a marked attenuation in body and organ weights, with a consistent decline in feed intake compared to HRCHFC diet fed rats. The test materials also caused a significant reduction in the blood pressure (systolic, diastolic, and mean) and heart rate of HRCHFC-diet fed rats. Improved glucose tolerance and insulin sensitivity tests were also observed in test material administered rats compare to only HRCHFC-diet fed rats. C. odorata and coumarin-treated animals produced a marked decline in serum FBG, TC, TG, LFTs, and RFTs, while an increase in serum HDL-C levels was noticed. C. odorata and coumarin also significantly modulated inflammatory biomarkers (TNFα, IL-6), adipokines (leptin, adiponectin, and chemerin), and HMG-CoA reductase levels, indicating prominent anti-inflammatory, cholesterol-lowering, and anti-hyperglycemic potential. Administration of C. odorata and coumarin exhibited a marked improvement in oxidative stress markers (CAT, SOD, and MDA). Histopathological analysis of liver, heart, kidney, pancreas, aorta, and fat tissues showed a revival of normal tissue architecture in C. odorata and coumarin-treated rats compared to only HRCHFC-diet fed rats. These results suggest that C. odorata and coumarin possess beneficial effects against the characteristic features of CMS (obesity, insulin resistance, hypertension, and dyslipidemia) in HRCHFC feed-administered rats. These effects were possibly mediated through improved adipokines, glucose tolerance, and insulin sensitivity, the attenuation of HMG-CoA reductase and inflammatory biomarkers, and modulated oxidative stress biomarkers. This study thus demonstrates a rationale for the therapeutic potential of C. odorata and coumarin in CMS.

Suspected rodenticide exposures in humans and domestic animals: Data from inquiries to the Norwegian Poison Information Centre, 2005-2020

Rodent control is necessary to prevent damage and spread of disease, and the most common pesticides used for urban and rural rodent control are anticoagulant rodenticides. The aim of this present study was to present data on suspected exposure to rodenticides in humans and domestic animals in Norway based on inquiries to the Norwegian Poison Information Centre in the 16-year period from 2005 through 2020. A total of 4235 inquiries regarding suspected exposures to rodenticides were registered in the study period. Of these, 1486 inquiries involved humans and 2749 animals. Second generation anticoagulants were involved in 68% of human exposures and 79% of animal exposures. Dogs were the most frequent species involved in the animal exposures with 93% of the inquiries, while cats were second most frequent involved. Around 50% of the human inquiries concerned children at the age of 0-4 years. Only 2% of the cases were in the age group 10-19 years, while adults comprised 35% of the inquiries. Acute poisonings accounted for almost 100% of the inquiries among both humans and animals. The exposure was accidental in 99% of the animal exposures and in 85% of the human exposures. In humans, only 14 inquiries were regarding occupational related accidents. Misdeed or self-inflicted injury accounted for 15% of the human inquiries and were the cause of 79% of the severe poisonings. Severe poisoning was only assessed in 1% of the cases involving children under 5 years. In contrast, 17% of the inquiries concerning adults (≥20 years) were assessed as severe. Subsequently, to prevent human and animal rodenticide exposure, we urge the use of non-chemical methods such as sanitation, rodent proofing (a form of construction which will impede or prevent rodents access to or from a given space or building) and mechanical traps. Restricting the use of rodenticides to professional pest controllers (or other persons with authorisation), reinforcing high quality education of these persons, and securing compliance of the best codes of practice could be advocated to reduce accidental exposure to rodenticides in humans and animals.

Use of tramadol and the risk of bleeding complications in patients on oral anticoagulants: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to determine whether tramadol intake increases the risk of bleeding in patients receiving oral anticoagulants.

METHODS

This systematic review was registered on PROSPERO, CRD42022327230. We searched PubMed and Embase up to 14 April 2022, and references and citations of included studies were screened. Comparative and non-comparative studies exploring bleeding complications among adult patients on oral anticoagulants and tramadol were included. Risk of bias was assessed using an adaptation of the Drug Interaction Probability Scale for case reports and case series and the Newcastle-Ottawa Scale for comparative studies. A meta-analysis was performed for the risk of serious bleeding (leading to hospitalisation or death) associated with tramadol in patients on vitamin K antagonists.

RESULTS

A total of 17 studies were included: 1 case series, 12 case reports, 2 case-control studies and 2 cohort studies. Most of the studies described tramadol-vitamin K antagonists' concomitant use; one case-control study also assessed dabigatran and rivaroxaban; one case report involved dabigatran. Among case reports/series, a total of 33 patients had a bleeding complication while using tramadol and an oral anticoagulant. The 4 comparative studies reported an increased bleeding risk during tramadol and vitamin K antagonist intake which was statistically significant in one study; the pooled risk ratio of serious bleeding was 2.68 [95% CI: 1.45 to 4.96; p < 0.001].

CONCLUSION

This systematic review confirms an association between tramadol use and risk of bleeding in patients on vitamin K antagonists. Evidence is too limited to assess whether this risk extends to patients on direct oral anticoagulants, and further studies are needed.

Perioperative Management of Ulcerative Colitis: A Systematic Review

BACKGROUND

Patients with ulcerative colitis may require colectomy for severe disease unresponsive or refractory to pharmacological therapy. Managing ulcerative colitis is complicated because there are many factors at play, including patient optimization and treatment, as the guidance varies on the ideal perioperative use of corticosteroids, immunomodulators, biologics, and small molecule agents.

OBJECTIVE

A systematic literature review was performed to describe the current status of perioperative management of ulcerative colitis.

DATA SOURCES

PubMed and Cochrane databases were used.

STUDY SELECTION

Studies published between January 2000 and January 2022, in any language, were included. Articles regarding pediatric or endoscopic management were excluded.

INTERVENTIONS

Perioperative management of ulcerative colitis was included.

MAIN OUTCOME MEASURES

Successful management, including reducing surgical complication rates, was measured.

RESULTS

A total of 121 studies were included in this review, including 23 meta-analyses or systematic reviews, 25 reviews, and 51 cohort studies.

LIMITATIONS

Qualitative review including all study types. The varied nature of study types precludes quantitative comparison.

CONCLUSION

Indications for colectomy in ulcerative colitis include severe disease unresponsive to medical treatment and colitis-associated neoplasia. Urgent colectomy has a higher mortality rate than elective colectomy. Corticosteroids are associated with postsurgical infectious complications and should be stopped or weaned before surgery. Biologics are not associated with adverse postoperative effects and do not necessarily need to be stopped preoperatively. Additionally, the clinician must assess individuals' comorbidities, nutrition status, and risk of venous thromboembolism. Nutritional imbalance should be corrected, ideally at the preoperative period. Postoperatively, corticosteroids can be tapered on the basis of the length of preoperative corticosteroid use.

Impact of Initial Warfarin Dosing on Time in Therapeutic Range for Postoperative Left Ventricular Assist Device Patients

ABSTRACT

Initial warfarin dosing and time in therapeutic range (TTR) are poorly characterized for early post-operative left ventricular assist device (LVAD) patients. This study evaluated TTR after LVAD implantation compared between patients receiving low-dose (<3 mg) and high-dose (≥3 mg) warfarin. This single-center, retrospective analysis included 234 LVAD patients who received warfarin within 5 days of implantation. The primary outcome was TTR during the 5 days following first international normalized ratio (INR) ≥2 compared between low-dose and high-dose groups. Secondary outcomes were hospital and intensive care unit length of stay, time to first INR ≥2, TTR after first INR ≥2, and reinitiation of parenteral anticoagulation. No difference in TTR was detected between warfarin groups (57.2% vs. 62.7%, P = 0.13). Multivariable analysis did not detect any factors predictive of TTR during the primary outcome timeframe, but age and body mass index were associated with the warfarin dose. The low-dose group received a mean warfarin dose of 1.9 mg (±0.64 mg), and the high dose group received 4.34 mg (±1.38 mg). Cohort TTR during the primary outcome timeframe was 60.5% and 56.5% for hospitalization. The low-dose group had longer intensive care unit length of stay, shorter time to therapeutic INR, and more frequently reinitiated parenteral anticoagulation. Patients with recent LVAD implantation are complex and have diverse warfarin sensitivity factors, which did not allow for optimal warfarin dose detection, although half of all patients received doses between 2.04 mg and 4.33 mg. Individualized dosing should be used, adjusting for patient-specific factors such as age, body mass index, and drug interactions.

Ferrocene-appended anthraquinone and coumarin as redox-active cytotoxins

Appending of ferrocene (Fc) to biologically-active organic backbones can generate novel multi-functional species for targeting bacteria and cancer. In this work Fc was linked to coumarin and anthraquinone with the goal of harnessing the redox-active Fc centre to generate new compounds that exhibit cytoxicity through the generation of toxic reactive oxygen species (ROS). A Cu(I)-catalyzed azide-alkyne cycloaddition "click" reaction was used to connect the organic and Fc components via a triazole linker. Cyclic voltammetry shows that the Fc potentials are suitable for oxidation by biological hydrogen peroxide to give reactive ferrocenium (Fc⁺) species, which can then generate hydroxyl radicals. The ability of the compounds to generate hydroxyl radicals in the presence of hydrogen peroxide was shown directly using EPR spin-trapping experiments. Furthermore, in vitro studies in MCF-7 breast cancer cells show significant increases in ROS following incubation with the Fc-functionalized compounds. Screening for antibacterial activity produced negative results for all of the Fc compounds, consitent with low levels of hydrogen peroxide typically found in bacteria. By contrast, Fc-coumarin showed cytotoxicity against A549 lung cancer and SKOV3 ovarian cancer cell lines, whereas the parent compound was inactive. This is consistent both with the cytoxic potential of the Fc group and the elevated hydrogen peroxide levels found in many cancers. Interestingly, the anthraquinone compounds showed the opposite effect with the parent compounds showing modest activity against A549 cells, but the Fc compounds being inactive. This demonstrates other potential negative impacts of including Fc, such as significantly increased lipophilicity.

In Search of the Optimal Antithrombotic Regimen for Intracerebral Hemorrhage Survivors with Atrial Fibrillation

Spontaneous intracerebral hemorrhage (ICH) constitutes 10-15% of all strokes, and is a significant cause of mortality and morbidity. Survivors of ICH, especially those with atrial fibrillation (AF), are at risk for both recurrent hemorrhagic and ischemic cerebrovascular events. A conundrum in the field of vascular neurology, neurosurgery, and cardiology has been the decision to initiate or resume versus withhold anticoagulation in survivors of ICH with AF. To initiate anticoagulation would decrease the risk of ischemic stroke but may increase the risk of hemorrhage. To withhold anticoagulation maintains a lower risk of hemorrhage but does not decrease the risk of ischemic stroke. In this narrative review, we discuss the evidence for and against the use of antithrombotics in ICH survivors with AF, focusing on recently completed and ongoing clinical trials.

Exploring the excited-state charge transfer fluorescence profile of 7-hydroxycoumarin and 2-methylimidazole - a combined X-ray diffraction and theoretical approach

This study investigated the effect of 2-methylimidazole (2-MIM) addition on the fluorescence of ethyl-7-hydroxy-2-oxo-2H-chromene-3-carboxylate using low-cost density functional theory (DFT) and Time-Dependent DFT calculations on single crystal X-ray geometries of ethyl-7-hydroxy-2-oxo-2H-chromene-3-carboxylate hydrate (1), 2-MIM (2), and the 1 : 1 co-crystal of (1) and (2), (3). At low concentrations (1 : 1-1 : 10) of 2-MIM, the fluorophore shows a decrease in the fluorescence intensity, but at higher concentrations (above 1 : 10) the fluorescence excitation maximum shifted from 354 nm to 405 nm, with a significant emission intensity increase. The changed excitation and emission profile at high concentrations is due to the deprotonation of the coumarin's phenolic group, which was confirmed by the increased shielding of the aromatic protons in the titration ¹H NMR spectra. The experimental fluorescence data between the 1 : 1 and 1 : 10 ratios agreed with the theoretical fluorescence data, with a redshift and decreased intensity when comparing (1) and (3). The data indicated that combining the fluorophore with 2-MIM increased levels of vibronic coupling between 2-MIM and the fluorophore decreasing de-excitation efficiency. These increased vibronic changes were due to charge transfer between the fluorophore and 2-MIM in (3). The subtle movement of the proton, H(5) toward N(2') (0.07 Å) caused a significant decrease in fluorescence due to electron density distribution (EDD) changes. This was identified by comparison of the EDD in the excited (S₁) and ground (S₀) states plotted as an isosurface of EDD difference. For the higher concentrations, an alternative excitation pathway was explored by modifying the crystal geometry of (3) based on ¹H NMR spectroscopy data to resemble excitoplexes. Theses excitoplex geometries reflected the fluorescence profile of the fluorophore with high concentrations of 2-MIM; there were dramatic changes in the theoretical fluorescence pathway, which was 100% vibronic coupling compared to 15.31% in the free fluorophore. At this concentration, the de-excitation pathway causes remodelling of the lactone ring via stretching/breaking the CO bond in the S₁ causing increased fluorescence by movement of the transition dipole moment. These results reflect previous studies, but the methods used are less experimentally and computationally expensive. This study is among the first to explain charge transfer fluorescence using crystalline geometries. This study will be of interest to the fields of crystal engineering and fluorescence spectroscopy.

Simultaneous Characterization and Determination of Warfarin and Its Hydroxylation Metabolites in Rat Plasma by Chiral Liquid Chromatography-Tandem Mass Spectrometry

Warfarin is extensively used for venous thromboembolism and other coagulopathies. In clinical settings, warfarin is administered as a mixture of S- and R-warfarin, and both enantiomers are metabolized by multiple cytochrome P450 enzymes into many hydroxylation metabolites. Due to the high degree of structural similarity of hydroxylation metabolites, their profile possesses significant challenges. The previous methods generally suffer from lacking baseline resolution and/or involving complex analysis processes. To overcome this limitation, a sensitive and specific chiral liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to simultaneously identify warfarin and hydroxywarfarins enantiomers. Chromatographic separation was achieved on a HYPERSIL CHIRAL-OT column. The mass spectrometric detection was carried out in negative ion MRM mode with electrospray ionization source. The optimized method exhibited satisfactory within-run and between-run accuracy and precision with lower limit of quantification (LLOQ) of 10.0 ng/mL and 1.0 ng/mL for warfarin and 7-, 10(R)-OH-warfarin enantiomers, respectively. Linear responses of warfarin enantiomers and 7-, and 10(R)-OH-warfarin enantiomers in rat plasma were observed over the range of 10.0–8000 ng/mL, and 1.00–800 ng/mL, respectively. The analytes were shown to be stable in various experimental conditions in rat plasma. Protein precipitation was used in sample preparation without a matrix effect. This method was successfully applied to pharmacokinetic study for quantitating the concentrations of S/R-warfarin, S/R-7-OH-warfarin, and S/R-10(R)-OH-warfarin and relatively quantitating 3′-, 4-, 6-, and 8-OH warfarin enantiomers in rat plasma.

Long Short-Term Memory Network for Development and Simulation of Warfarin Dosing Model Based on Time Series Anticoagulant Data

Background

Warfarin is an effective treatment for thromboembolic disease but has a narrow therapeutic index, and dosage can differ tremendously among individuals. The study aimed to develop an individualized international normalized ratio (INR) model based on time series anticoagulant data and simulate individualized warfarin dosing.

Methods

We used a long short-term memory (LSTM) network to develop an individualized INR model based on data from 4,578 follow-up visits, including clinical and genetic factors from 624 patients whom we enrolled in our previous randomized controlled trial. The data of 158 patients who underwent valvular surgery and were included in a prospective registry study were used for external validation in the real world.

Results

The prediction accuracy of LSTM_INR was 70.0%, which was much higher than that of MAPB_INR (maximum posterior Bayesian, 53.9%). Temporal variables were significant for LSTM_INR performance (51.7 vs. 70.0%, P < 0.05). Genetic factors played an important role in predicting INR at the onset of therapy, while after 15 days of treatment, we found that it might unnecessary to detect genotypes for warfarin dosing. Using LSTM_INR, we successfully simulated individualized warfarin dosing and developed an application (AI-WAR) for individualized warfarin therapy.

Conclusion

The results indicate that temporal variables are necessary to be considered in warfarin therapy, except for clinical factors and genetic factors. LSTM network may have great potential for long-term drug individualized therapy.

Trial Registration

NCT02211326; www.chictr.org.cn:ChiCTR2100052089.

External Evaluation of a Bayesian Warfarin Dose Optimization Based on a Kinetic-Pharmacodynamic Model

Warfarin is a representative anticoagulant with large interindividual variability. The published kinetic-pharmacodynamic (K-PD) model allows the prediction of warfarin dose requirement in Swedish patients; however, its applicability in Japanese patients is not known. We evaluated the model's predictive performance in Japanese patients with various backgrounds and relationships using Bayesian parameter estimation and sampling times. A single-center retrospective observational study was conducted at Tokyo Women's Medical University, Medical Center East. The study population consisted of adult patients aged >20 years who commenced warfarin with a prothrombin time-international normalized ratio (PT-INR) from June 2015 to June 2019. The published K-PD model modified by Wright and Duffull was assessed using prediction-corrected visual predictive checks, focusing on clinical characteristics, including age, renal function, and individual prediction error. The external dataset included 232 patients who received an initial warfarin daily dose of 3.2 ± 1.28 mg with 2278 PT-INR points (median [range] follow-up period of 23 d [7-28]). Prediction-corrected visual predictive checks carried a propensity for underprediction. Additionally, age >60 years, body mass index ≤25 kg/m², and estimated glomerular filtration rate ≤60 mL/min/1.73 m² had a pronounced tendency to underpredict PT-INR. However, Bayesian prediction using four prior observations reduced underprediction. To improve the prediction performance of these special populations, further studies are required to construct a model to predict warfarin dose requirements in Japanese patients.

Evaluation of Anticoagulation Control among Patients Taking Warfarin in University of Gondar Hospital, Northwest Ethiopia

INTRODUCTION

Warfarin is a widely used oral anticoagulant in clinical practice. It has variable intraindividual and interindividual dose response and a narrow therapeutic index. Therefore, it requires frequent and regular international normalized ratio (INR) determination to maintain the INR within the therapeutic range. The study evaluated parameters of anticoagulation control among patients on warfarin.

METHODS

A cross-sectional study was conducted at University of Gondar hospital. A consecutive sampling method was used to recruit study subjects. The anticoagulation control was evaluated by determining the proportion of desired INRs and the proportion of time spent in the therapeutic range (TTR). Logistic regression analysis was used to identify associated factors with adequate TTR. A P value <0.05 was used to declare significant association.

RESULT

A total of 338 study subjects were included in the study. The mean age of patients was 48.8 (SD = 16.4) years. Atrial fibrillation was the commonest indication for warfarin therapy. One-third (33%) of study subjects achieved the desired INRs of 2.0-3.0, while about one-tenth (13%) of patients attained good INR control (TTR ≥ 65%). Multivariate logistic regression analysis revealed no significant association of sociodemographic and clinical characteristics with good TTR outcome.

CONCLUSION

The level of anticoagulation control with warfarin among study subjects was very low. The authors recommend to implement a validated warfarin-dose titration protocol and to establish anticoagulation clinics to mitigate the low anticoagulation level.

The influence of Javanese turmeric (Curcuma xanthorrhiza) on the pharmacokinetics of warfarin in rats with single and multiple-dose studies

CONTEXT

Co-administration between warfarin (WF) and Curcuma xanthorrhiza Roxb. (Zingiberaceae) (CX) is found in Indonesian patients and need to be evaluated.

OBJECTIVE

This study assesses the effect of concomitant administration of CX extract on the pharmacokinetics of WF in rats.

MATERIALS AND METHODS

Wistar rats were divided into 4 groups (n = 6) and administered with 2% Pulvis Gummi Arabicum (PGA, control), fluconazole (FZ, 6 mg/kg), CX-1 (6 mg/kg) or CX-2 (18 mg/kg BW) for 7 days. For the single-dose study, at the 8th day, WF (1 mg/kg) was administered to all groups and blood samples were taken from 0.25 to 72 h. For the multiple-dose study, daily dose of WF was administered to all groups of rats and at the 7th to 9th day, the rats were treated with PGA, CX-1, CX-2 and FZ. Blood samples were withdrawn daily at 4 h after administration of WF from the 1st to 11th day.

RESULTS

The area under the curve (AUC) of R- and S-WF in the CX-2 group was a significantly higher value compared to the control (77.54 vs. 35.27 mg.h/L for R-WF and 316.26 vs. 40.16 mg.h/L for S-WF; p < 0.05; Kruskal-Wallis method). The CX-2 administration also caused the increasing in the concentration level of R-WF (16%) and S-WF (27%) from the 7th to 9th day of administration.

DISCUSSION AND CONCLUSIONS

The CX administration in a higher dose caused alteration on WF pharmacokinetics suggesting the need for clinical evaluation of the interaction between CX and WF.

Evaluation of an Initiation Regimen of Warfarin for International Normalized Ratio Target 2.0 to 3.0

Background: he number of patients on warfarin therapy is rising steadily. Although warfarin is beneficial, it carries a high risk of bleeding, especially if the international normalized ratio (INR) values exceed 3.0. Currently, no warfarin initiation regimens have been developed for the Asian population, especially for Malaysians. Objective: This article describes the efficacy and safety of a new initiation regimen for warfarin among warfarin-naive patients. Method: Data were retrospectively collected from the ambulatory and inpatient settings. Results: A total of 165 patients who each had a target INR of 2.0 to 3.0 were included in the study. The mean age was 57.2 years and 94 patients were male. A total of 108 patients used Regimen 1 (5 mg/5 mg/3mg) and the rest of the patients used Regimen 2 (5 mg/3 mg/3 mg). Most patients used warfarin either for atrial fibrillation (52.1%) or for venous thromboembolism (29.7%). Overall, 88 of the patients had INR values above 50% from the baseline on Day 4. Additionally, 13 patients had INR values of >3.2, which required withholding and lower dose of warfarin. The predicted weekly maintenance warfarin dose (23 ± 0.5 mg/week) was found to have correlated closely with the actual maintenance dose (22.8 ± 0.5 mg/week; r ² = 0.75). Nearly two thirds (70.3%) of the patients achieved the target INR on Day 11. Conclusion: The warfarin initiation regimens in this study was simple, safe, and suitable to be used in both ambulatory and inpatient settings for managing warfarin therapy.

Safety and efficacy of low-dose non-vitamin K antagonist oral anticoagulants versus warfarin after left atrial appendage closure with the Watchman device

BACKGROUND/PURPOSE

Anticoagulant therapy is suggested within 45 days after Watchman device implantation for stroke prevention in patients with atrial fibrillation (AF). A previous study demonstrated that non-vitamin K antagonist oral anticoagulants (NOACs) were a feasible peri- and postprocedural alternative to warfarin. The present study aimed to compare the safety and efficacy of using different anticoagulants (low-dose NOACs vs. warfarin) within 45 days after Watchman device implantation in a Chinese population.

METHODS

Patients with successful Watchman device implantation from October 2014 to June 2020 were included. All patients received anticoagulants within 45 days after the procedure, and those patients were divided into three groups according to the type of postprocedural anticoagulants. Transesophageal echocardiography follow-up was performed 45 days post procedure to assess residual flow and the occurrence of device-related thrombus (DRT).

RESULTS

A total of 368 patients were enrolled in the study. The study population was divided into three groups: the warfarin group (n = 77), the dabigatran group (n = 165) and the rivaroxaban group (n = 126). Periprocedural major bleeding was higher in the warfarin group (2.6% vs. 0% vs. 0%, P = 0.043), while minor bleeding was comparable among the groups (3.9% vs. 1.2% vs. 0.8%, P = 0.230). No periprocedural transient ischemic attack/stroke occurred. At follow-up, the incidence of DRT was higher in the warfarin group than in the other groups (4.2% vs. 0.6% vs. 0.8%; P = 0.116), but the difference was not statistically significant. The rates of thromboembolic and bleeding events were similar in the three groups.

CONCLUSION

The safety and efficacy of low-dose dabigatran and rivaroxaban were comparable to those of warfarin within 45 days after Watchman device implantation in a Chinese population.

The Effects of Osteoporotic and Non-osteoporotic Medications on Fracture Risk and Bone Mineral Density

Osteoporosis is a highly prevalent bone disease affecting more than 37.5 million individuals in the European Union (EU) and the  United States of America (USA). It is characterized by low bone mineral density (BMD), impaired bone quality, and loss of structural and biomechanical properties, resulting in reduced bone strength. An increase in morbidity and mortality is seen in patients with osteoporosis, caused by the approximately 3.5 million new osteoporotic fractures occurring every year in the EU. Currently, different medications are available for the treatment of osteoporosis, including anti-resorptive and osteoanabolic medications. Bisphosphonates, which belong to the anti-resorptive medications, are the standard treatment for osteoporosis based on their positive effects on bone, long-term experience, and low costs. However, not only medications used for the treatment of osteoporosis can affect bone: several other medications are suggested to have an effect on bone as well, especially on fracture risk and BMD. Knowledge about the positive and negative effects of different medications on both fracture risk and BMD is important, as it can contribute to an improvement in osteoporosis prevention and treatment in general, and, even more importantly, to the individual's health. In this review, we therefore discuss the effects of both osteoporotic and non-osteoporotic medications on fracture risk and BMD. In addition, we discuss the underlying mechanisms of action.

Statistical reanalysis of vascular event outcomes in primary and secondary vascular prevention trials

BACKGROUND

Vascular prevention trials typically use dichotomous event outcomes although this may be inefficient statistically and gives no indication of event severity. We assessed whether ordinal outcomes would be more efficient and how to best analyse them.

METHODS

Chief investigators of vascular prevention randomised controlled trials that showed evidence of either benefit or harm, or were included in a systematic review that overall showed benefit or harm, shared individual participant data from their trials. Ordered categorical versions of vascular event outcomes (such as stroke and myocardial infarction) were analysed using 15 statistical techniques and their results then ranked, with the result with the smallest p-value given the smallest rank. Friedman and Duncan's multiple range tests were performed to assess differences between tests by comparing the average ranks for each statistical test.

RESULTS

Data from 35 trials (254,223 participants) were shared with the collaboration. 13 trials had more than two treatment arms, resulting in 59 comparisons. Analysis approaches (Mann Whitney U, ordinal logistic regression, multiple regression, bootstrapping) that used ordinal outcome data had a smaller average rank and therefore appeared to be more efficient statistically than those that analysed the original binary outcomes.

CONCLUSIONS

Ordinal vascular outcome measures appear to be more efficient statistically than binary outcomes and provide information on the severity of event. We suggest a potential role for using ordinal outcomes in vascular prevention trials.

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.

Managing Anticoagulant Patients Undergoing Dental Extraction by using Hemostatic Agent: Tranexamic Acid Mouthrinse

Background:

Patient who is on antiplatelet therapy had an impaired fibrin formation which leads to fibrinolysis which is the main reason behind postextraction bleeding.

Objectives:

The aim of the study is to manage anticoagulated patient who has to undergo dental extraction by using hemostatic agent and the objective is to rule out potential risk factor which may trigger bleeding.

Methods:

One hundred patients with anticoagulant and antiplatelet therapy and having International Normalized Ratio (INR) in-between 1.9 and 3.5 were selected. Postextraction instruction use 5 ml of 10% tranexamic acid mouthrinse four times a day for next 7 days was suggested. All demographic data, history of anticoagulant and antiplatelet therapy, details of bleeding, and treatment requirement were recorded to identify potential risk factor.

Results:

Of 100 subjects, 16 were reported postextraction bleeding on days 1 and 2 which was controlled by tranexamic acid pressure pack. Bleeding from extraction socket of 10 patients was stopped by gelatin foam. No life-threatening risk was observed. In patients with age group of 41–60 years whose INR value was ≥2.5, the number of teeth undergoing extraction, whose bleeding time was increased, and were on long duration of antiplatelet and anticoagulation therapy might increase the risk of bleeding.

Conclusion:

Use of tranexamic acid mouthrinse after extraction is an effective way to control bleeding on patients who are under antiplatelet therapy with at therapeutic INR level is a secure and allowable method of minimizing postextraction oozing.

Self-care training and informational support of patients with a mechanical heart valve on the international normalized ratio and bleeding complications

AIM

The aim of the study was to determine the effect of self-care training and informational support of patients with a mechanical heart valve on the international normalized ratio (INR) and bleeding complications.

MATERIAL AND METHODS

Design: A quasi-experimental study. Participants were recruited via convenience sampling and were randomly divided into two groups: control (n = 80) and intervention (n = 80). Participants in the control group received only routine training; in addition, the intervention group received 6 sessions of self-care training and 6 months of informational support. Monthly the level of INR and incidence of bleeding were determined. Data were analyzed using the independent t-test and χ2 in SPSS16 software at a significance level of 0.05.

RESULTS

During 6 months of follow-up, except for the third month, the frequency of INR levels in the therapeutic target range (2.5-3.5) in the intervention group was significantly higher than that in the control group (p < 0.05). Also in the intervention group, the incidence of bleeding complications was lower than that in the control group, but this difference was not statistically significant (p > 0.05).

CONCLUSIONS

Proper self-care training and informational support in patients with mechanical heart valve replacement have positive results. By maintaining self-care, the level of a therapeutic target range of INR can be maintained and the incidence of bleeding complications can be reduced.

Towards The Automated, Empirical Filtering of Drug-Drug Interaction Alerts in Clinical Decision Support Systems: Historical Cohort Study of Vitamin K Antagonists

Background

Drug-drug interactions (DDIs) involving vitamin K antagonists (VKAs) constitute an important cause of in-hospital morbidity and mortality. However, the list of potential DDIs is long; the implementation of all these interactions in a clinical decision support system (CDSS) results in over-alerting and alert fatigue, limiting the benefits provided by the CDSS.

Objective

To estimate the probability of occurrence of international normalized ratio (INR) changes for each DDI rule, via the reuse of electronic health records.

Methods

An 8-year, exhaustive, population-based, historical cohort study including a French community hospital, a group of Danish community hospitals, and a Bulgarian hospital. The study database included 156,893 stays. After filtering against two criteria (at least one VKA administration and at least one INR laboratory result), the final analysis covered 4047 stays. Exposure to any of the 145 drugs known to interact with VKA was tracked and analyzed if at least 3 patients were concerned. The main outcomes are VKA potentiation (defined as an INR≥5) and VKA inhibition (defined as an INR≤1.5). Groups were compared using the Fisher exact test and logistic regression, and the results were expressed as an odds ratio (95% confidence limits).

Results

The drugs known to interact with VKAs either did not have a statistically significant association regarding the outcome (47 drug administrations and 14 discontinuations) or were associated with significant reduction in risk of its occurrence (odds ratio<1 for 18 administrations and 21 discontinuations).

Conclusions

The probabilities of outcomes obtained were not those expected on the basis of our current body of pharmacological knowledge. The results do not cast doubt on our current pharmacological knowledge per se but do challenge the commonly accepted idea whereby this knowledge alone should be used to define when a DDI alert should be displayed. Real-life probabilities should also be considered during the filtration of DDI alerts by CDSSs, as proposed in SPC-CDSS (statistically prioritized and contextualized CDSS). However, these probabilities may differ from one hospital to another and so should probably be calculated locally.

Mechanical valve replacement without anticoagulation: a case report

Background

For patients who undergo mechanical valve replacement, the greatest disadvantage is that they require long-term or permanent use of anticoagulant therapy to prevent thromboembolism. To date, mechanical valve replacement without anticoagulation has been published in the literature.

Case summary

We present the case of a 75-year-old female who underwent mechanical mitral valve replacement (MVR) on mid-June, 2007. However, this patient had not been taking anticoagulant medication since she experienced warfarin overdose in the first month after the operation. She had been well without using any anticoagulation, and there were no complications of the mechanical valve.

Discussion

There was no thrombosis for such a long period of time because she suffered from FX deficiency. To the best of our knowledge, she may be the only patient who has been well without any anticoagulation since not taking warfarin 12 years ago.

Impact of PCSK9, WDR12, CDKN2A, and CXCL12 Polymorphisms in Jordanian Cardiovascular Patients on Warfarin Responsiveness and Sensitivity

Background

The main objective of this study is sought to determine the impacts of PCSK9, WDR12, CDKN2A, and CXCL12 polymorphisms on warfarin sensitivity and responsiveness in Jordanian cardiovascular patients during the initiation and stabilization phases of therapy.

Methods

This study took place at the anticoagulation clinic at Queen Alia Heart Institute (QAHI) in Jordan. DNA samples were collected from 212 cardiovascular patients and 213 healthy controls. Genomic SNPs genotyping was conducted using the MassARRAY System at the Australian Genome Research Facility.

Results

This study assessed 10 polymorphisms (rs11206510 within the PCSK9 gene, rs6725887 and rs7582720 within the WDR12 gene, rs4977574, rs10757278, and rs1333049 within the CDKN2A gene, rs2862116, rs7906426, rs1746048, and rs268322 within the CXCL12 gene) in 212 Jordanian cardiovascular patients. Carriers of CDKN2A rs1333049, rs10757278, and PCSK9 rs11206510 polymorphisms had an increased risk of resistance during the initiation phase of warfarin therapy compared to those who do not carry it, or those who are carrying one polymorphism only (P < 0.05), while carriers of CXCL12 rs7906426 polymorphism had similar increased risk but during the stabilization phase of warfarin therapy (P < 0.05).

Conclusion

Carriers of CXCL12 rs2862116 polymorphism had an increased risk to be warfarin extensive responders compared to those with no or only one polymorphism (P = 0.01). However, the presence of PCSK9 rs11206510 polymorphism affects the warfarin maintenance doses (P ˃ 0.0001).

Interactions between Antidepressants and Warfarin: A Review

Background:

Since warfarin has a very narrow therapeutic index, the interaction between warfarin and antidepressants is very critical and has potentially severe consequences. It is unclear whether clinicians have sufficient knowledge about the risk of bleeding when warfarin and antidepressants are used concomitantly.

Objective:

In this systematic review, we discuss the main considerations when using warfarin with antidepressants.

Methods:

The information about warfarin-antidepressant interactions was obtained from Google Scholar®, PubMed/MEDLINE® and a hand search of the published literature. The following research terms which were systematically combined with each other to find articles: warfarin, anticoagulant, interactions, antidepressant (and each antidepressant name individually), SSRI, SNRI, TCA, MAOI.

Results:

Several possible mechanisms that can cause bleeding when antidepressants and warfarin are used concomitantly, have been discussed. According to the available data, sertraline and citalopram/ escitalopram are safer antidepressants to use with warfarin, whereas fluoxetine and fluvoxamine have a higher interaction potential with warfarin. The remaining antidepressants appear to lie somewhere in between and have little empirical data to guide the clinicians.

Conclusion:

It is recommended that when an antidepressant is prescribed to a patient using warfarin, patient’s international normalized ratio (INR) level should be checked regularly. In this review, the interaction between warfarin and antidepressants, including new ones, were evaluated inclusively and in detail.

Comparison of Surgical Site Infection Risk Between Warfarin, LMWH, and Aspirin for Venous Thromboprophylaxis in TKA or THA: A Systematic Review and Meta-Analysis

BACKGROUND

Infection following arthroplasty can have devastating effects for the patient and necessitate further surgery. Venous thromboembolism (VTE) prophylaxis is required to minimize the risk of deep venous thrombosis and pulmonary embolism. Anticoagulation has been demonstrated to interfere with wound-healing and increase the risk of infection. We hypothesized that different anticoagulation regimes will have differing effects on rates of periprosthetic joint infection. The aim of this study was to compare the surgical site infection risk between the use of warfarin, low-molecular-weight heparin (LMWH), and aspirin for VTE prophylaxis following total knee or hip arthroplasty.

METHODS

A systematic literature search was conducted in November 2018 using the PubMed, CINAHL, and Cochrane Central Register of Controlled Trials (CENTRAL) databases to identify studies that compared warfarin, LMWH, and/or aspirin with regard to surgical site infection rates following hip or knee arthroplasty. Meta-analyses were performed to compare the infection and VTE risks between groups.

RESULTS

Nine articles involving 184,037 patients met the inclusion criteria. Meta-analysis showed that warfarin prophylaxis was associated with a higher risk of deep infection (or infection requiring reoperation) (odds ratio [OR] = 1.929, 95% confidence interval [CI] = 1.197 to 3.109, p = 0.007) and surgical site infection overall (OR = 1.610, 95% CI = 1.028 to 2.522, p = 0.038) compared with aspirin in primary total joint arthroplasty, with similar findings also seen when primary and revision procedures were combined. There was no significant difference in infection risk between warfarin and LMWH and between LMWH and aspirin. There was a nonsignificant trend for VTE risk to be higher with warfarin compared with aspirin therapy for primary procedures (OR = 1.600, 95% CI = 0.875 to 2.926, p = 0.127), and this was significant when both primary and revision cases were included (OR = 2.674, 95% CI = 1.143 to 6.255, p = 0.023).

CONCLUSIONS

These findings caution against the use of warfarin for VTE prophylaxis for hip and knee arthroplasty. Further randomized head-to-head trials and mechanistic studies are warranted to determine how specific anticoagulants impact infection risk.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

In vitro fermentation and isolation of heparin-degrading bacteria from human gut microbiota

Heparin and its derivative are commonly used as injectable anticoagulants in clinical procedures, but possess poor oral bioavailability. To explore the role of gut microbiota in the poor oral effect of heparin, the degradation profiles of heparin on six human gut microbiota were investigated. The heparin-degradation ability varied significantly among individuals. Furthermore, two strains of heparin-degrading bacteria, Bacteroides ovatus A2 and Bacteroides cellulosilyticus B19, were isolated from the gut microbiota of different individuals and the degradation products of the isolates were profiled. The ΔUA2S-GlcNS6S was the major end product with almost no desulfation. 3-O-sulfo group-containing tetrasaccharides were detected, which indicated that the antithrombin binding site was broken and this explained the lost anticoagulant activity of heparin. Collectively, the present study assessed the degradation profiles of heparin by human gut microbiota and provided references for the development of oral administration of heparin from a gut microbiota perspective.

New oral anticoagulants for nonvalvular atrial fibrillation with stable coronary artery disease: A meta-analysis

BACKGROUND

New oral anticoagulants (NOACs) are effective and safe in patients with nonvalvular atrial fibrillation (NVAF). Limited evidence is available regarding outcomes for NVAF patients with stable coronary artery disease (CAD).

METHODS

A systematic search of Medline, Embase, and the Cochrane Register was performed. Two reviewers independently performed data extraction and quality assessment using the Cochrane Collaboration risk-of-bias assessment tool. We evaluated all primary publications and secondary analyses comparing NOACs with any other OAC agent for preventing stroke in patients with both NVAF and stable CAD from phase III clinical randomized control trials. The primary outcomes were stroke, systemic embolism (SE), major bleeding, and intracranial hemorrhage (ICH), and the secondary outcomes were cardiovascular (CV) death, all-cause death, and myocardial infarction (MI).

RESULTS

Four articles with a total of 19 266 patients were included in this study. The pooled results showed a relative risk for stroke/SE with NOACs of 0.83 (95% confidence interval [CI]: 0.71-0.97), for major bleeding 0.85 (95% CI: 0.63-1.14), for ICH 0.36 (95% CI: 0.19-0.54), for MI 1.00 (95% CI: 0.82-1.20), for CV death 0.94 (95% CI: 0.83-1.06), and for all-cause death 0.95 (95% CI: 0.85-1.07).

CONCLUSION

NOACs were effective in preventing stroke/SE and reducing the risk of ICH in patients with both NVAF and CAD.

Cost-effectiveness of direct oral anticoagulants versus vitamin K antagonist in atrial fibrillation: A study protocol using Real-World Data from Catalonia (FantasTIC Study)

BACKGROUND

Anticoagulant therapy is used for stroke prevention and proved to be effective and safe in the long term. The study aims to analyse the cost-effectiveness relationship of using of direct-acting oral anticoagulants vs vitamin K antagonists to prevent ischaemic stroke in patients with nonvalvular atrial fibrillation, including all the active ingredients marketed in Spain, prescribed for 2 years in the Primary Care service of the Institut Català de la Salut.

METHODS

Population-based cohort study, in which the cost of the 2 treatment groups will be evaluated. Direct costs (pharmacy, primary care, emergency and hospitalization) and indirect costs (lost productivity) will be included from a social perspective. Effectiveness (assessed as the occurrence of a health event, the 1 of primary interest being stroke) will be determined, with a 2-year time horizon and a 3% discount rate. The average cost of the 2 groups of drugs will be compared using a regression model to determine the factors with the greatest influence on determining costs. We will carry out a univariate ('one-way') deterministic sensitivity analysis.

DISCUSSION

We hope to provide relevant information about direct and indirect costs of oral anticoagulants, which, together with aspects of effectiveness and safety, could help shape the consensual decision-making of evaluating bodies.