Guidance for the practical management of warfarin therapy in the treatment of venous thromboembolism

Periprocedural Management of Oral Anticoagulation

Decisions surrounding periprocedural anticoagulation management must balance thromboembolic and procedural bleed risk. The interruption of both warfarin and DOACs requires consideration of anticoagulant pharmacokinetics, procedural bleed risk and patient characteristics. There is a diminishing role for periprocedural bridging LMWH overall and no role for bridging LMWH for the procedural interruption of DOACs. A clinical approach to perioperative DOAC management based on operative bleeding risk and renal function is safe and effective, and at present, is preferred over preprocedural DOAC levels testing. Clear communication of the anticoagulation interruption plan to both the patient and the patient's care team is essential.

Direct Determination of Coagulation Factor IIa and Plasmin Activities for Monitoring of Thrombotic State

Background

Current laboratory examinations for hypercoagulable diseases focus on the biomarker content of the activated coagulation cascade and fibrinolytic system. Direct detection of physiologically important protease activities in blood remains a challenge. This study aims to develop a general approach that enables the determination of activities of crucial coagulation factors and plasmin in blood.

Methods

This assay is based on the proteolytic activation of an engineered zymogen of l-phenylalanine oxidase (proPAO), for which the specific blood protease cleavage sites were engineered between the inhibitory and activity domains of proPAO. Specific cleavage of the recombinant proenzyme leads to the activation of proPAO, followed by oxidation and oxygenation of l-phenylalanine, resulting in an increase of chromogenic production when coupled with the Trinder reaction.

Results

We applied this method to determine the activities of both coagulation factor IIa and plasmin in their physiologically relevant basal state and fully activated state in sodium citrate–anticoagulated plasma respectively. Factor IIa and plasmin activities could be dynamically monitored in patients with thrombotic disease who were taking oral anticoagulants and used for assessing the hypercoagulable state in pregnant women.

Conclusions

The high specificity, sensitivity, and stability of this novel assay not only makes it useful for determining clinically important protease activities in human blood and diagnosing thrombotic diseases but also provides a new way to monitor the effectiveness and safety of anticoagulant drugs.

First-Line Therapies for VTE Treatment and Secondary Prophylaxis in Patients With Cancer: A New Direction

Objective:

To review evidence behind anticoagulants in cancer-associated venous thromboembolism (VTE) with a focus on low-molecular-weight heparins (LMWH) and the role of direct oral anticoagulants (DOACs).

Data Sources:

PubMed was searched using terms “venous thromboembolism,” “cancer,” and “anticoagulation.” This search was restricted to clinical trials, meta-analyses, and subgroup analyses. Additional references were identified from reviewing literature citations.

Study Selection:

English-language prospective and retrospective studies assessing the efficacy and safety of LMWH and DOACs in patients with cancer.

Data Analysis:

Several trials were analyzed that compared anticoagulation therapies for prevention of recurrent VTE in patients with cancer. Many studies comparing LMWH and vitamin K antagonists (VKAs) found nonsignificant differences between therapies. A single study demonstrated that LMWHs are superior to VKAs. This evidence supporting LMWH for long-term VTE treatment in patients with cancer is based on comparison to VKA, but results are limited by methodological issues, and the benefit of LMWH may be driven by poor control. Subanalyses of DOAC trials suggest these are equally or more effective as VKA in cancer, but this conclusion is underpowered.

Conclusion:

DOACs have the potential to bypass many challenges with traditional therapy. After analyzing the evidence available, we conclude that after careful consideration of risks and benefits, use of DOACs for VTE treatment are a reasonable option in patients with cancer.

Risk of Bleeding with Exposure to Warfarin and Nonsteroidal Anti-Inflammatory Drugs: A Systematic Review and Meta-Analysis

BACKGROUND

 Warfarin use can trigger the occurrence of bleeding independently or as a result of a drug-drug interaction when used in combination with nonsteroidal anti-inflammatory drugs (NSAIDs).

OBJECTIVES

 This article examines the risk of bleeding in individuals exposed to concomitant warfarin and NSAID compared with those taking warfarin alone (Prospero Registry ID 145237).

METHODS

 PubMed, EMBASE, Scopus, and Web of Science were searched. The primary outcome of interest was gastrointestinal bleeding and general bleeding. Summary effects were calculated to estimate average treatment effect using random effects models. Heterogeneity was assessed using Cochran's Q and I ². Risk of bias was also assessed using the Agency for Healthcare Research and Quality bias assessment tool.

RESULTS

 A total of 651 studies were identified, of which 11 studies met inclusion criteria for meta-analysis. The odds ratio (OR) for gastrointestinal bleeding when exposed to warfarin and an NSAID was 1.98 (95% confidence interval [CI]: 1.55-2.53). The risk of gastrointestinal bleeding was also significantly elevated with exposure to a COX-2 inhibitor and warfarin relative to warfarin alone (OR = 1.90, 95% CI: 1.46-2.46). There was an increased risk of general bleeding with the combination of warfarin with NSAIDs (OR = 1.58, 95% CI: 1.18-2.12) or COX-2 inhibitors (OR = 1.54, 95% CI: 0.86-2.78) compared with warfarin alone.

CONCLUSION

 Risk of bleeding is significantly increased among persons taking warfarin and a NSAID or COX-2 inhibitor together as compared with taking warfarin alone. It is important to caution patients about taking these medications in combination.

Rivaroxaban treatment for young patients with pulmonary embolism (Review)

Pulmonary embolism (PE) is a serious, life-threatening condition that affects young populations (>18 and <50 years old, according to most literature reviews) with improved recognition of its clinical manifestations and the widespread use of sensitive imaging techniques, PE is increasingly diagnosed in younger patients. At present, there is limited understanding of the clinical features and adequate anticoagulant treatment options for this population. Most studies to date have yet to demonstrate significant differences in PE pathophysiology or symptoms between young and elderly patients. Although the overall incidence of PE is lower in young populations compared with elderly patients, important risk factors also apply for young patients. Hereditary thrombophilia is common and is a major cause of PE in younger patients. Immobilization, trauma, obesity, smoking and infection are also becoming increasingly frequent in young patients with PE. Among female patients, oral contraceptive use, pregnancy and postpartum status are predominant risk factors underlying PE. Rivaroxaban is a direct oral anticoagulant with a rapid onset of action that is associated with less drug-drug interactions compared with other therapies. Because the drug is administered at fixed doses with no requirement for routine coagulation monitoring, it is becoming an attractive option for anticoagulation treatment in young patients with PE. Therefore, the present literature review focuses on the clinical characteristics of PE and rivaroxaban therapy in younger patients.

Vitamin K for reversal of excessive vitamin K antagonist anticoagulation: a systematic review and meta-analysis

Patients receiving vitamin K antagonists (VKAs) with an international normalized ratio (INR) between 4.5 and 10 are at increased risk of bleeding. We systematically reviewed the literature to evaluate the effectiveness and safety of administering vitamin K in patients receiving VKA therapy with INR between 4.5 and 10 and without bleeding. Medline, Embase, and Cochrane databases were searched for relevant randomized controlled trials in April 2018. Search strategy included terms vitamin K administration and VKA-related terms. Reference lists of relevant studies were reviewed, and experts in the field were contacted for relevant papers. Two investigators independently screened and collected data. Risk ratios (RRs) were calculated, and certainty of the evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation. Six studies (1074 participants) were included in the review and meta-analyses. Pooled estimates indicate a nonsignificant increased risk of mortality (RR = 1.42; 95% confidence interval [CI], 0.62-2.47), bleeding (RR = 2.24; 95% CI, 0.81-7.27), and thromboembolism (RR = 1.29; 95% CI, 0.35-4.78) for vitamin K administration, with moderate certainty of the evidence resulting from serious imprecision as CIs included potential for benefit and harm. Patients receiving vitamin K had a nonsignificant increase in the likelihood of reaching goal INR (1.95; 95% CI, 0.88-4.33), with very low certainty of the evidence resulting from serious risk of bias, inconsistency, and imprecision. Our findings indicate that patients on VKA therapy who have an INR between 4.5 and 10.0 without bleeding are not likely to benefit from vitamin K administration in addition to temporary VKA cessation.

Assessment of agreement and time in therapeutic range of capillary versus venous international normalised ratio in frail elderly people in a nursing home

Vitamin K antagonists are widely used, yet have a slim therapeutic margin and high iatrogenicity. Patients are monitored through international normalised ratio (INR) by venipuncture, but coagulometers could measure INR by capillary puncture. This prospective study evaluated the clinical concordance of capillary INR versus venous INR in 31 nursing home patients. Concordance was good and mean time in therapeutic range (TTR) markedly increased. Capillary INR is thus reliable, could improve TTR and decrease iatrogenicity.

A Unique Formulation of Cardioprotective Bio-Actives: An Overview of Their Safety Profile

The burden of cardiovascular disease (CVD) remains high globally and in the United States despite the availability of pharmaceuticals aimed at its prevention and treatment. An invention by Summit Innovation Labs, which is a formula consisting of a unique blend of select polyphenols (i.e., curcumin, quercetin, resveratrol), vitamin K2 as menaquinone-7, and magnesium, was recently developed to modulate the impact of the specific drivers of CVD, namely, vascular calcification, oxidative stress, and chronic inflammation. The SIL formulation is a dietary supplement that was designed leveraging the more bioavailable forms of ingredients with poor absorption, such as curcumin and quercetin. Each ingredient within the SIL formulation has been shown to contribute to CVD risk reduction by moderating the effect of CVD triggers, thereby providing a holistic prevention strategy for CVD in the healthy population. This review focuses on recently published clinical data to support the safety profile of these ingredients following oral administration. The preponderance of clinical trial data reviewed support the overall safety of the bioactives when used singly or in combination. The most commonly reported adverse effects were generally mild dose-related gastrointestinal disturbances, which may be alleviated with diet in some cases. In light of these, we conclude that the combination of the ingredients in the SIL formulation is reasonably expected to be safe.

A descriptive study of antithrombotic medication patterns in adult patients with recent venous thromboembolism

Objectives:

The objective of this study is to describe the most common self-reported antithrombotic therapy utilization patterns in a national cohort of patients with recent venous thromboembolism (VTE).

Methods:

Extant data from a national online survey administered to 907 patients 18 years of age or older with VTE in the last two years were analyzed. Patients’ self-reported antithrombotic usage patterns used during three phases of treatment for the most recent VTE episode were summarized using descriptive statistics.

Results:

The following overall antithrombotic usage patterns were identified: warfarin (38.7%), direct oral anticoagulants (DOACs) (26.1%), switching between warfarin and DOACs (13.3%), aspirin only (8.7%), switching between different DOACs (4.5%), injectable anticoagulants only (3.9%), and no treatment (4.7%). Extended antithrombotic therapy beyond 90 days was reported by 65.7% of patients. Aspirin coadministration with anticoagulant therapy occurred for 33.7%.

Conclusions:

In this national sample of recent VTE sufferers warfarin therapy remains the most used anticoagulant followed closely by DOAC therapy. Switching between warfarin and DOACs and between different DOACs was common which could indicate adverse events or affordability issues. Aspirin coadministration with anticoagulant therapy was present in 1 of 3 patients and is a potential medication safety intervention for anticoagulation providers.

Systematic review of interventions to improve safety and quality of anticoagulant prescribing for therapeutic indications for hospital inpatients

PURPOSE

Anticoagulation-associated adverse drug events are common in hospitalised patients and result in morbidity, mortality, increased length of hospital stay and higher costs of care. Many are preventable. We reviewed the literature to identify and assess interventions intended to improve safety or quality anticoagulant prescribing.

METHODS

A systematic search of EMBASE, MEDLINE, the Cochrane Library, Pretty Darn Quick-Evidence and Health Systems Evidence was undertaken to identify controlled studies assessing system-level interventions to improve prescribing of oral or parenteral therapeutic anticoagulation for any indication in hospitalised adults. Data were extracted for safety and quality outcomes, with studies grouped by intervention type for meta-analysis and narrative review.

RESULTS

Of 10,640 records screened, 19 trials evaluating 12,742 participants were included for analysis. No study specifically evaluated prescribing of low molecular weight heparins (LMWHs) or direct acting oral anticoagulants (DOACs). Our findings suggest that physician-led anticoagulation consultation services may reduce bleeding rates in high-risk patients. On meta-analysis, decision supported warfarin dosing resulted in higher proportion of time with international normalised ratio in therapeutic range (p = 0.0007). Studies of other clinical decision support systems and heparin monitoring systems did not demonstrate improved safety, and quality findings were inconsistent. Systematic education and feedback programs were not efficacious.

CONCLUSIONS

There is currently insufficient high-quality evidence to recommend any reviewed intervention, though several warrant closer evaluation. Adequately powered controlled trials assessing safety outcomes and evidence-based quality markers in high-risk patient groups and studies of interventions to improve safety of LMWH and DOAC prescribing are needed.

Providers' utilization and perceptions of warfarin dosing algorithms

INTRODUCTION

Warfarin dosing algorithms have proven beneficial in increasing time within therapeutic range (TTR) and decreasing adverse events associated with out-of-range international normalized ratios (INRs). Despite widespread availability, providers' utilization and perceptions of warfarin algorithms in real-world practice are unclear. Identifying perceptions and barriers to algorithm use may help attempts to improve warfarin therapy management.

METHODS

Anticoagulation providers' utilization and perceptions of warfarin dosing algorithms were assessed via a nationwide electronic survey.

RESULTS

Of the 246 providers who completed the survey, 82% were pharmacists, and 69% had over five years' experience dosing warfarin. Warfarin dosing algorithms were deemed beneficial by 84% of respondents and 72% currently use a warfarin dosing algorithm in their practice at least occasionally. Pharmacists were least likely of anticoagulation providers to use algorithms, although this was not statistically significant (p = 0.12). Algorithm utilization also decreased as years of warfarin dosing experience increased, with the highest rate of usage noted in the first year of dosing warfarin. The most common reason providers gave for discontinuing algorithm use was that they no longer felt it was needed. In this study, clinic patient volume did not appear to be associated with algorithm utilization.

CONCLUSION

Warfarin dosing algorithms are frequently used among anticoagulation providers, especially those new to dosing warfarin, but use is frequently not sustained over the long-term. Education on the continued benefits of warfarin dosing algorithms could increase long-term utilization, potentially improving patient outcomes.

Treatment in the dental practice of the patient receiving anticoagulation therapy

BACKGROUND

The use of anticoagulants is ubiquitous in outpatient medical practice, with anticoagulants now among the most common classes of medications prescribed in the United States. Despite its safety, anticoagulation around minimally invasive dental procedures remains a source of discomfort for dental practitioners and a common reason for referral to specialist anticoagulation clinics. The introduction of new anticoagulant options, as well as the changing practice pattern in anticoagulant prescription, somewhat contributes to this situation. Reviewing the commonly used anticoagulants in outpatient medical practice, as well as their implications in dental practice, is integral to providing safe oral health care.

CONCLUSIONS

Direct oral anticoagulants are now the preferred agents for most patients receiving anticoagulation therapy. With patients receiving any type of therapeutic anticoagulation, clinicians usually can perform dental procedures such as restorations, limited dental extractions, endodontic procedures, soft-tissue biopsies, and scalings safely without anticoagulation therapy interruption. Although local hemostatic maneuvers are often sufficient during dental procedures, antifibrinolytic medications, as well as local sponges and glues, can be used to ensure adequate hemostasis. Different classes of anticoagulants interact with commonly prescribed medications in unique ways and may require differing management and monitoring.

PRACTICAL IMPLICATIONS

Clinicians can perform most dental procedures safely despite patients' receiving therapeutic anticoagulation. Recognizing common classes of anticoagulants, incorporating strategies to minimize bleeding, and understanding how commonly prescribed medications in dentistry interact with anticoagulants are essential to practicing safe, comprehensive care.

Rivaroxaban for the treatment of venous thromboembolism in real life: A single-center prospective study

The clinical profile, evolution and complications of treatment with rivaroxaban in a cohort of patients presenting with venous thromboembolism (VTE) were analyzed in an observational, non-interventional and prospective study.A total of 111 patients were included in the study. Clinical data were collected from the medical history of the patients and recorded in a specific database.Mean age was 63.8 ± 17.4 years, 53.2% of patients were men, 55.9% had at least another concomitant condition, and 40.9% at least 1 VTE risk factor. 54.1% of patients presented with deep venous thrombosis, 32.4% with pulmonary embolism and 13.5% with both conditions simultaneously. The 61% of patients were admitted to hospital and mean hospital length-of-stay was 8.8 ± 9.9 days. After a mean follow-up 530 ± 464 days (median follow-up of 405 days), 3.9% of patients died and VTE recurrence occurred in 2.9% of patients. While receiving rivaroxaban, a first bleeding complication occurred in 8.1%; all events were minor bleeding.Our study supports the current literature data and confirms the similar results of real-life VTE patients with those enrolled in the rivaroxaban pivotal clinical trials. Rivaroxaban may facilitate outpatient treatment and might be considered as a first-line therapy for the management of VTE patients.

Association between polymorphisms of VKORC1 and CYP2C9 genes with warfarin maintenance dose in a group of warfarin users in Birjand city, Iran

Warfarin is the cardinal anticoagulant drug prescribed around the world. Due to stochastic bleeding in patients, it is essential to adjust the dose for every individual. The aim of the present study was to evaluate the frequency of CYP2C9 and VKORC1 gene polymorphisms and their association with warfarin maintenance dose in a sample of cardiovascular patients in Birjand, South-Khorasan province of Iran. Patients with a history of cardiovascular disorders who take warfarin daily were selected. CYP2C9 and VKORC1 gene polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism in all participants. A total of 114 patients (mean age: 52.7 ± 14.9 years, M/F ratio: 0.76) participated in this study. Regarding CYP2C9 gene polymorphisms, the most frequent genotype was 1*/1* (80.4% in females and 62.5% in males). The frequency of 1*/2* and 2*/2* variants was 13% and 6.5% in females and 25% and 12.5% in males, respectively. The frequency of VKORC1 gene (1639 G > A), was 31.5%, 39.5%, and 29% for GG, GA, and AA in males, respectively. Besides, the mentioned genotype frequencies for females were 50%, 40.5%, and 9.5%, respectively. Moreover, there was a statistically significant correlation between VKORC1 gene -1639 G > A variant and warfarin maintenance dose (P < 0.001) but not for CYP2C9 variants. The results of the current study confirmed that the mutant variants of CYP2C9 are not frequent and do not have any impact on warfarin dose. In the case of VKORC1, the mutant allele (A) showed a positive correlation with warfarin dose adjustment.

The effect of online versus hospital warfarin management on patient outcomes: a systematic review and meta-analysis

Background Patients using oral anticoagulants are prone both to thrombus from insufficient anticoagulant therapy and to bleeding by overmedication, so there is a need for further exploring. Aim of the review To assess the effect of online management (using electronic communication such as smartphone), and hospital management on the outcome of patients on long-term anticoagulant therapy, and to explore an appropriate anticoagulation management model. Method Studies published in English prior to July 2017 were retrieved from PubMed, EMBASE, Web of Science, and the Cochrane Library. Two researchers screened the literature independently, extracted the data and evaluated the methodological quality of the included studies. Meta-analysis was conducted using RevMan 5.3 software. The publication bias analysis was evaluated. Results A total of ten studies met the inclusion criteria, covering 16,915 patients. Of these, 8260 cases formed the online anticoagulation management group, and the other 8655 cases the hospital anticoagulant management group. There were no significant differences between the management models for time in therapeutic range, incidence of major or minor bleeding events, thromboembolic events, or warfarin-related emergency department visits. However, online management was associated with fewer warfarin-related hospital admissions than hospital management (odds ratio: 0.47, 95% confidence interval [0.30, 0.73]; P = 0.0009). Conclusion The online management of anticoagulant therapy was not inferior to hospital management, and may provide more convenient, higher quality anticoagulant therapy services for patients.

Impact of incorporating ABCB1 and CYP4F2 polymorphisms in a pharmacogenetics-guided warfarin dosing algorithm for the Brazilian population

PURPOSE

Interpatient variation of warfarin dose requirements may be explained by genetic variations and general and clinical factors. In this scenario, diverse population-calibrated dosing algorithms, which incorporate the main warfarin dosing influencers, have been widely proposed for predicting supposed warfarin maintenance dose, in order to prevent and reduce adverse events. The aim of the present study was to evaluate the impact of the inclusion of ABCB1 c.3435C>T and CYP4F2 c.1297G>A polymorphisms as additional covariates in a previously developed pharmacogenetic-based warfarin dosing algorithm calibrated for the Brazilian population.

METHODS

Two independent cohorts of patients treated with warfarin (n = 832 and n = 133) were included for derivation and replication of the algorithm, respectively. Genotyping of ABCB1 c.3435C>T and CYP4F2 c.1297G>A polymorphisms was performed by polymerase chain reaction followed by melting curve analysis and TaqMan® assay, respectively. A multiple linear regression was performed for the warfarin stable doses as a dependent variable, considering clinical, general, and genetic data as covariates.

RESULTS

The inclusion of ABCB1 and CYP4F2 polymorphisms was able to improve the algorithm's coefficient of determination (R²) by 2.6%. In addition, the partial determination coefficients of these variants revealed that they explained 3.6% of the warfarin dose variability. We also observed a marginal improvement of the linear correlation between observed and predicted doses (from 59.7 to 61.4%).

CONCLUSION

Although our study indicates that the contribution of the combined ABCB1 and CYP4F2 genotypes in explaining the overall variability in warfarin dose is not very large, we demonstrated that these pharmacogenomic data are statistically significant. However, the clinical relevance and cost-effective impact of incorporating additional variants in warfarin dosing algorithms should be carefully evaluated.

Defining Minimum Necessary Anticoagulation-Related Communication at Discharge: Consensus of the Care Transitions Task Force of the New York State Anticoagulation Coalition

BACKGROUND

Anticoagulated patients are particularly vulnerable to ADEs when they experience changes in medical acuity, pharmacotherapy, or care setting, and resources guiding care transitions are lacking. The New York State Anticoagulation Coalition convened a task force to develop a consensus list of requisite data elements (RDEs) that should accompany all anticoagulated patients undergoing care transitions.

METHODS

A multidisciplinary panel of 15 anticoagulation experts voluntarily completed an iterative Delphi process. Resources were disseminated and deliberated via remote technology, with consensus achieved via blinded electronic polling.

RESULTS

The panel reached consensus on a list of 15 RDEs for anticoagulation communication at discharge (the ACDC List). Consensus was rapidly achieved by the full panel on 13 elements, while 3 (2 of which were combined into 1 element) required multiple iterations and achieved consensus with votes from 8 available panelists. The elements encompassed a range of factors, including drug use and indications, previous exposure and duration of therapy, recent drug exposure and laboratory results and expectations for subsequent administration, therapy goals, patient education and comprehension, and expectations for clinical management. Twelve of the elements are applicable to any anticoagulant, and 3 are specific to warfarin.

CONCLUSION

The ACDC List identifies specific pieces of clinical information that a panel of anticoagulant experts agree should be communicated to downstream providers for all anticoagulated patients undergoing care transitions. Additional study is needed to objectively evaluate the ability of existing care systems to communicate the elements and to assess possible relationships between communication of the elements and clinical outcomes.

Association Between ABCB1 Polymorphism and Stable Warfarin Dose Requirements in Brazilian Patients

The ideal dose of the oral anticoagulant warfarin varies widely among patients, mainly due to genetic factors. Genetic variations that impact warfarin pharmacokinetics and the vitamin K cycle are plausible candidates for being associated with warfarin dose requirements. Therefore, the aim of this study was to assess whether polymorphisms in the ABCB1 and CYP4F2 genes were associated with stable warfarin dose requirements in Brazilian patients. This retrospective study included samples from 309 individuals. Genotyping of ABCB1 c.3435C>T and CYP4F2 c.1297G>A were performed by polymerase chain reaction followed by melting curve analysis (HRM-PCR) and TaqMan® genotyping assay, respectively. Stable doses were adjusted in a linear multiple regression model for age, gender, body mass index, self-reported race, use of amiodarone, CYP2C9 (^*2 and ^*3), VKORC1 c.1639G>A, and ABCB1 c.3435C>T or CYP4F2 c.1297G>A. By performing a univariate analysis of variance, we found that the warfarin patients who carry ABCB1 c.3435T variant alleles (CT and TT genotypes) need fewer warfarin stable doses in comparison with the individuals that are CC wild-type: 2.5 (p = 0.003) and 4.3 (p < 0.001) mg/week less, respectively, for the overall group of patients on stable anticoagulation therapeutics (n = 309); and 5.5 (p = 0.006) and 10.2 (p < 0.001) mg/week less, respectively, for the self-declared non-white stable subgroup (n = 76). No statistically significant differences in dose requirements were observed according to CYP4F2 genotypes. In conclusion, our results suggest ABCB1 c.3435C>T variant may influence warfarin dose requirements in Brazilian patients, when associated with other genotypic, demographic and clinical factors.

Patient Education on Oral Anticoagulation

Given the potential harm associated with anticoagulant use, patient education is often provided as a standard of care and emphasized across healthcare settings. Effective anticoagulation education involves face-to-face interaction with a trained professional who ensures that the patient understands the risks involved, the precautions that should be taken, and the need for regular monitoring. The teaching should be tailored to each patient, accompanied with written resources and utilize the teach-back method. It can be incorporated in a variety of pharmacy practice settings, including in ambulatory care clinics, hospitals, and community pharmacies.

Non-variceal upper gastrointestinal bleeding

Non-variceal upper gastrointestinal bleeding (NVUGIB) is bleeding that develops in the oesophagus, stomach or proximal duodenum. Peptic ulcers, caused by Helicobacter pylori infection or use of NSAIDs and low-dose aspirin (LDA), are the most common cause. Although the incidence and mortality associated with NVUGIB have been decreasing owing to considerable advances in the prevention and management of NVUGIB over the past 20 years, it remains a common clinical problem with an annual incidence of ∼67 per 100,000 individuals in the United States in 2012. NVUGIB is a medical emergency, and mortality is in the range ∼1-5%. After resuscitation and initial assessment, early (within 24 hours) diagnostic and therapeutic endoscopy together with intragastric pH control with proton pump inhibitors (PPIs) form the basis of treatment. With a growing ageing population treated with antiplatelet and/or anticoagulant medications, the clinical management of NVUGIB is complex as the risk between gastrointestinal bleeding events and adverse cardiovascular events needs to be balanced. The best clinical approach includes identification of risk factors and prevention of bleeding; available strategies include continuous treatment with PPIs or H. pylori eradication in those at increased risk of developing NVUGIB. Treatment with PPIs and/or use of cyclooxygenase-2-selective NSAIDs should be implemented in those patients at risk of NVUGIB who need NSAIDs and/or LDA.

Anticoagulation increases alveolar hemorrhage in mice infected with influenza A

Influenza A virus infection is a common respiratory tract infection. Alveolar hemorrhage has been reported in patients with influenza pneumonia and in mice infected with influenza A. In this study, we investigated the effect of two anticoagulants on alveolar hemorrhage after influenza A virus (IAV) infection of wild‐type mice. Wild‐type mice were anticoagulated with either warfarin or the direct thrombin inhibitor dabigatran etexilate and then infected with a mouse‐adapted influenza virus (A/Puerto Rico/8/34 H1N1). Alveolar hemorrhage was assessed by measuring hemoglobin levels in the bronchoalveolar lavage fluid (BALF). We also measured vascular permeability and viral genomes in the lung, as well as white blood cells, inflammatory mediators, and protein in BALF. Survival and body weight were monitored for 14 days after influenza A infection. In infected mice receiving either warfarin or dabigatran etexilate we observed decreased activation of coagulation in the BALF and increased alveolar hemorrhage. Warfarin but not dabigatran etexilate increased vascular permeability and mortality of influenza A‐infected mice. Anticoagulation did not affect levels of influenza A genomes, white blood cells, inflammatory mediators, or protein in the BALF. Our study indicates that systemic anticoagulation increases alveolar hemorrhage in influenza A‐infected mice.

Diabetes mellitus is associated with increased bleeding in pulmonary embolism receiving conventional anticoagulant therapy: findings from a "real-world" study

Bleeding refers to the most important complication during anticoagulation therapy in patients with pulmonary embolism (PE). However, the incidence and risk factors of bleeding in Chinese population with anticoagulant therapy remains unknown. Although diabetes mellitus (DM) has been demonstrated to increase the risk of PE, little information of its influence on anticoagulation-associated bleeding risk can be available. In our study, 563 acute PE patients, who fulfilled the including criteria were enrolled from a single center and received conventional anticoagulant therapy. And there were 539 patients completed the 3 months following-up. The cumulative incidences of major bleeding (MB) and clinically relevant non-major bleeding (CRNMB) were 3.0% (95% CI 1.01-3.05) and 14.0% (95% CI 1.47-5.21), respectively. Besides, anemia (OR 3.52, 95% CI 1.12-11.41) and recent history of MB (OR 8.14, 95% CI 1.41-31.95) were independently associated with MB. Age >65 year (OR 1.51, 95% CI 1.12-3.11), cancer (OR 2.01, 95% CI 1.12-4.01) and therapeutic range (TTR) during 3 months (OR 0.93, 95% CI 0.91-0.98) were independently associated with CRNMB. Additionally, DM was an independent risk factor for both MB (OR 2.11, 95% CI 1.10-4.12) and CRNMB (OR 2.11, 95% CI 1.10-4.12). Notably, the incidence of MB or CRNMB was significantly higher in DM patients than non-DM patients. At the end of 3-month follow-up, the HbA1C in CRNMB group was 8.3%, yet it was 7.0% in non-CRNMB group among diabetic patients (p = 0.04). In conclusions, the bleeding rates are high in patients with acute PE who receive anticoagulant therapy. In addition to the already known bleeding risk factors, DM can also increase the bleeding risk significantly. Thus, good glycemic control may be essential after prescription of anticoagulant therapy.

Transition of stable patients from traditional anticoagulation clinic services to telephonic management

Background Outpatient warfarin dosing and monitoring with telephonic anticoagulation management (TAM) could be an effective alternative to other more labor intensive management models. Objectives To evaluate the time in therapeutic range (TTR) and number of extreme INR values (<1.5 or >4.5) of a telephonic system of warfarin management for stable patients who currently utilized traditional anticoagulation management services (AMSs). Method A retrospective, observational cohort with three groups (1) patients transitioned from an office-based anticoagulation clinic to TAM, (2) patients continuously enrolled in office-based AMS, (3) patients continuously managed by usual physician care without specialized anticoagulation services (UPC). Data was collected for six months before and six months after transition. Results All groups demonstrated decreased TTR from baseline to active phase, with the TAM and AMS groups showing similar magnitude of reduction (-10.61 and -12.66% respectively) but UPC group producing a greater drop (-20.08%). The TAM and AMS groups had similar rates of extreme INR levels; UPC had higher numbers of extreme INRs in three of the four measurements. Conclusion Stable patients transitioned from office-based anticoagulation clinic to a telephonic model of management performed equally as well as those who continued traditional enrollment.

Hemostasis, bleeding and thrombosis in liver disease

The presence of cirrhosis poses an increased risk of both thrombosis and bleeding in individuals with chronic liver disease. This duality is a result of a dynamic disequilibrium between procoagulant and anticoagulant states in individuals with cirrhosis. The mechanism of this imbalance in cirrhosis remains unclear. It is known that the progression of cirrhosis leads to decreased synthetic function and a concurrent lack of natural anticoagulants. Other proposed mechanisms contributing to this hemostatic imbalance include decreased platelet production, increased platelet destruction from hypersplenism, decreased synthesis of Vitamin K-dependent and independent clotting factors and anticoagulant factors, and alterations in purinergic signaling pathways.

Given the current state of flux in our understanding of bleeding and thrombophilia in cirrhosis, the recommendations for treatment of these conditions are still evolving.

We provide a current update on the proposed pathophysiology of altered hemostasis and thrombophilia in cirrhosis. We discuss recent studies in portal vein thrombosis (PVT) and venous thromboembolism (VTE), which are the common thrombotic consequences of cirrhosis, resulting in substantive morbidity and mortality. To address these, we discuss new prophylactic interventions and current treatment options to manage the heightened risk of thrombosis in cirrhosis, while limiting hemorrhagic complications.