The use of direct oral anticoagulants in chronic kidney disease

Role of platelet count in a murine stasis model of deep vein thrombosis

Platelets are core components of thrombi but their effect on thrombus burden during deep vein thrombosis (DVT) has not been fully characterized. We examined the role of thrombopoietin-altered platelet count on thrombus burden in a murine stasis model of DVT. To modulate platelet count compared to baseline, CD1 mice were pretreated with thrombopoietin antisense oligonucleotide (THPO-ASO, 56% decrease), thrombopoietin mimetic (TPO-mimetic, 36% increase), or saline (within 1%). Thrombi and vein walls were examined on postoperative days (POD) 3 and 7. Thrombus weights on POD 3 were not different between treatment groups (p = .84). The mean thrombus weights on POD 7 were significantly increased in the TPO-mimetic cohort compared to the THPO-ASO (p = .005) and the saline (p = .012) cohorts. Histological grading at POD 3 revealed a significantly increased smooth muscle cell presence in the thrombi and CD31 positive channeling in the vein wall of the TPO-mimetic cohort compared to the saline and THPO-ASO cohorts (p < .05). No differences were observed in histology on POD 7. Thrombopoietin-induced increased platelet count increased thrombus weight on POD 7 indicating platelet count may regulate thrombus burden during early resolution of venous thrombi in this murine stasis model of DVT.

Apixaban Use in Patients with Kidney Impairment: A Review of Pharmacokinetic, Interventional, and Observational Study Data

Chronic kidney disease (CKD) remains a significant global health issue and is a leading cause of mortality worldwide. Patients with CKD have an increased risk of developing atrial fibrillation (AF) and venous thromboembolism (VTE). While direct oral anticoagulants (DOACs) have become a standard of care for anticoagulation (AC) in patients with AF and VTE, the appropriate use of these agents in comorbid kidney impairment warrants detailed discussion. This scientific narrative review summarizes the effectiveness and safety of apixaban use in patients with renal dysfunction by assessing the current published pharmacokinetic, interventional, observational, and guideline data. Apixaban is a highly selective, orally active, direct inhibitor of factor Xa, with well-established pharmacokinetics and consistent clinical outcomes across a broad range of patient populations, including those with kidney impairment. Overall, the scientific literature has shown that apixaban has a favorable clinical efficacy and safety profile compared with vitamin K antagonists for patients with AF or VTE and comorbid kidney impairment. These data support the approved label dosing strategy of apixaban in reducing the risk of stroke/systemic embolism in patients with nonvalvular AF and in treating VTE across all ranges of kidney function. Both clinician experience and knowledge of patient-specific factors may be required in the management of comorbid patients with advanced CKD or those requiring dialysis, as data on these patients are limited.

A real-world exploration into clinical outcomes of direct oral anticoagulant therapy in people with chronic kidney disease: a large hospital-based study

BACKGROUND

There is limited evidence to support definite clinical outcomes of direct oral anticoagulant (DOAC) therapy in chronic kidney disease (CKD). By identifying the important variables associated with clinical outcomes following DOAC administration in patients in different stages of CKD, this study aims to assess this evidence gap.

METHODS

An anonymised dataset comprising 97,413 patients receiving DOAC therapy in a tertiary health setting was systematically extracted from the multidimensional electronic health records and prepared for analysis. Machine learning classifiers were applied to the prepared dataset to select the important features which informed covariate selection in multivariate logistic regression analysis.

RESULTS

For both CKD and non-CKD DOAC users, features such as length of stay, treatment days, and age were ranked highest for relevance to adverse outcomes like death and stroke. Patients with Stage 3a CKD had significantly higher odds of ischaemic stroke (OR 2.45, 95% Cl: 2.10-2.86; p = 0.001) and lower odds of all-cause mortality (OR 0.87, 95% Cl: 0.79-0.95; p = 0.001) on apixaban therapy. In patients with CKD (Stage 5) receiving apixaban, the odds of death were significantly lowered (OR 0.28, 95% Cl: 0.14-0.58; p = 0.001), while the effect on ischaemic stroke was insignificant.

CONCLUSIONS

A positive effect of DOAC therapy was observed in advanced CKD. Key factors influencing clinical outcomes following DOAC administration in patients in different stages of CKD were identified. These are crucial for designing more advanced studies to explore safer and more effective DOAC therapy for the population.

The Safety of Direct Oral Anticoagulants Compared to Warfarin in Patients Hospitalized With Acute Kidney Injury

BACKGROUND

Direct oral anticoagulants (DOACs) are preferred over warfarin for many indications, though their safety has not been well established in patients with acute renal impairment.

OBJECTIVE

The purpose of this study was to evaluate the frequency of bleeding complications associated with DOACs compared with warfarin in patients admitted to the hospital with acute kidney injury (AKI).

METHODS

This was a retrospective cohort study evaluating patients admitted to the Penn Medicine Lancaster General Hospital with a diagnosis of AKI from October 2017 through September 2021 and receiving therapy with oral anticoagulants. Comparing DOACs with warfarin, the primary endpoint was the percent frequency of composite major and minor bleeding during the admission and within 30 days of discharge.

RESULTS

There were 112 hospitalization encounters included in the study. Of these, 42 (37.5%) patients were receiving warfarin and 70 (62.5%) patients were receiving DOAC therapy before admission. There was a higher frequency of the primary endpoint of bleeding in patients receiving DOACs as compared with warfarin, though this was not statistically significant (18.5% vs. 11.9%, respectively, P = 0.432). There were no differences between groups in the frequency of major bleeding, minor bleeding, or transfusions. Patients receiving DOAC therapy were more likely to experience anticoagulation-related readmissions or emergency department visits compared with patients on warfarin therapy (11.4% vs. 0%, P = 0.024).

CONCLUSION AND RELEVANCE

Direct oral anticoagulants and warfarin were associated with statistically similar rates of bleeding in patients presenting with AKI. Further research is necessary to elucidate if DOACs are safer than warfarin in this patient population.

Risk of post-sphincterotomy bleeding with antiplatelet and anticoagulant use: a propensity-matched analysis of the U.S. Collaborative Network

BACKGROUND AND AIMS

GI bleeding after ERCP is a serious adverse event and most commonly occurs after endoscopic biliary and/or pancreatic sphincterotomy. Although the strength of available evidence for post-sphincterotomy GI bleeding risk is high for therapeutic warfarin and heparin, it remains unknown for antiplatelet agents like clopidogrel and prasugrel. We conducted a retrospective United States-based, propensity-matched cohort study to assess the risk of post-sphincterotomy bleeding in patients receiving anticoagulant (AC) and antiplatelet (APT) therapy.

METHODS

We analyzed the U.S. Collaborative Network in the TriNetX platform through December 27, 2022, to include patients receiving APT and AC therapy who underwent ERCP within 7 days of hospitalization. One-to-one propensity score matching was performed. The primary outcome was the incidence of GI bleeding within 7 days of sphincterotomy. Secondary outcomes included need for blood transfusion, intensive care unit care, and all-cause mortality within 30 days of bleeding.

RESULTS

Overall, 2806 patients (1806 in the AC cohort and 1000 in the APT cohort) underwent ERCP with sphincterotomy. One-to-one propensity score matching was performed for age, body mass index ≥30 kg/m2, gender, race, ethnicity, diabetes mellitus, nicotine dependence, presence and severity of chronic kidney disease, cirrhosis, and thrombocytopenia between the cohorts. Patients in both cohorts had an increased risk of post-sphincterotomy bleeding compared with matched control subjects (adjusted odds ratios of 3.6 [95% confidence interval, 2.58-5.06] and 2.2 [95% confidence interval, 1.43-3.56], respectively). Although heparin bridging therapy and concurrent use of aspirin did not further increase the risk of GI bleeding, resumption of AC within 24 hours' postprocedure did. Neither cohort of patients was at an increased risk for blood transfusion, intensive care unit care, or all-cause mortality.

CONCLUSIONS

Our database analysis shows that patients receiving AC and APT therapy are at a higher risk of post-sphincterotomy bleeding compared with matched control subjects. An appropriate drug cessation period or alternative biliary decompression modalities may be used in these patients.

Risk of post-extraction bleeding with direct oral anticoagulant compared with warfarin: Retrospective cohort study using large scale claims data in Japan

INTRODUCTION

Comparative safety of direct oral anticoagulants vs. warfarin in patients undergoing tooth extraction remains unclear. We compared the incidence of post-extraction bleeding between patients taking warfarin and those taking direct oral anticoagulants (DOACs) using administrative claims data.

MATERIALS AND METHODS

We identified outpatients on anticoagulant therapy who underwent permanent tooth extraction between 2015 and 2020 and categorized them into the warfarin and DOAC groups based on medication prescribed within six months prior to tooth extraction. We used the overlap propensity score weighting method to balance the baseline characteristics between the groups and compared the incidence of post-extraction bleeding within seven days after tooth extraction.

RESULTS

Among 5253 eligible patients, those in the DOAC group (n = 3696) were older and less frequently prescribed antiplatelets than those in the warfarin group (n = 1557). The distribution of tooth extraction type and number of teeth extracted in a single procedure did not differ between the groups. The unadjusted incidences of post-extraction bleeding in the warfarin and DOAC groups were 35 (2.2 %) and 71 (1.9 %), respectively. Moreover, the overlap weighting analysis showed that the adjusted odds ratio of post-extraction bleeding in the DOAC group in comparison with that in the warfarin group was 0.84 (95 % confidence interval, 0.54-1.31).

CONCLUSION

The incidence of post-extraction bleeding in patients taking DOACs was comparable to that in patients taking warfarin. The findings suggest that dentists and physicians should exercise the same degree of caution when extracting teeth in patients on DOACs and those on warfarin in terms of post-extraction bleeding.

Direct Oral Anticoagulants versus Vitamin K Antagonists in Individuals Aged 80 Years and Older: An Overview in 2021

Two main types of oral anticoagulants are available in France: vitamin K antagonists (VKA) and, more recently, direct oral anticoagulants (DOAC). The benefit−risk profile appears to be favorable for DOAC, which is as effective as VKA but safer (fewer cases of severe and cerebral bleeding). In a study in 2017, we observed that older adults did not seem to receive the same modalities of oral anticoagulants as younger individuals for various reasons. To assess anticoagulation prescribing practices over time, we repeated this cross-sectional study by comparing very old individuals taking DOAC to those taking VKA. Ambulatory individuals aged 80 years and older were included. They were affiliated with the Mutualité Sociale Agricole of Burgundy and were refunded for a medical prescription of oral anticoagulation in March 2021. The demographic characteristics, registered chronic diseases (RCD), number and types of prescribed drugs, and mortality of the DOAC group and the VKA group were compared. A total of 4275 subjects were included in the study: 67.44% (2883) received DOAC and 32.56% (1392) received VKA. The two groups were similar in age. In the DOAC group, there were more women (54.98% vs. 46.98%) (p < 0.001), fewer RCD (91.47% vs. 93.68%) (p = 0.014), and lower rates of venous thromboembolism (2.53% vs. 6.75%) (p < 0.001), severe heart failure (56.50% vs. 68.03%) (p < 0.001), and severe kidney diseases (1.38% vs. 3.59%) (p < 0.001), but there were more subjects with Alzheimer’s disease (7.49% vs. 4.31%) (p = 0.001). Individuals in the DOAC group had fewer prescriptions of furosemide (48.53% vs. 55.75%) (p < 0.001) and fibrates (2.32% vs. 3.88%) (p = 0.044). They also had more prescriptions of proton pump inhibitors (43.95% vs. 39.44%) (p = 0.006) and antirheumatics (1.60% vs. 0.65%) (p = 0.009) than those in the VKA group. There was no difference in mortality. This study revealed that prescribing practices for DOAC have changed over time.

Challenges and Possible Solutions to Direct-Acting Oral Anticoagulants (DOACs) Dosing in Patients with Extreme Bodyweight and Renal Impairment

This article aims to highlight the dosing issues of direct oral anticoagulants (DOACs) in patients with renal impairment and/or obesity in an attempt to develop solutions employing advanced data-driven techniques. DOACs have become widely accepted by clinicians worldwide because of their superior clinical profiles, more predictable pharmacokinetics, and hence more convenient dosing relative to other anticoagulants. However, the optimal dosing of DOACs in extreme bodyweight  patients and patients with renal impairment is difficult to achieve using the conventional dosing approach. The standard dosing approach (fixed-dose) is based on limited data from clinical studies. The existing formulae (models) for determining the appropriate doses for these patient groups leads to suboptimal dosing. This problem of mis-dosing is worsened by the lack of standardized laboratory parameters for monitoring the exposure to DOACs in renal failure and extreme bodyweight patients. Model-informed precision dosing (MIPD) encompasses a range of techniques like machine learning and pharmacometrics modelling, which could uncover key variables and relationships as well as shed more light on the pharmacokinetics and pharmacodynamics of DOACs in patients with extreme bodyweight or renal impairment. Ultimately, this individualized approach-if implemented in clinical practice-could optimise dosing for the DOACs for better safety and efficacy.

When Is It Preferable to Use Warfarin?

Warfarin Versus Direct Oral AnticoagulantsDespite the growing popularity of DOACs, data in specific populations have provided a stark reminder that the equivalence (or superiority) of DOACs to warfarin cannot be assumed across the board. These results have raised an increasingly common clinical question: When is it preferable to use warfarin?

Arrhythmias in Chronic Kidney Disease

Arrhythmias cause disability and an increased risk of premature death in the general population but far more so in patients with renal failure. The association between the cardiac and renal systems is complex and derives in part from common causality of renal and myocardial injury from conditions including hypertension and diabetes. In many cases, there is a causal relationship, with renal dysfunction promoting arrhythmias and arrhythmias exacerbating renal dysfunction. In this review, the authors expand on the challenges faced by cardiologists in treating common and uncommon arrhythmias in patients with renal failure using pharmacological interventions, ablation and cardiac implantable device therapies. They explore the most important interactions between heart rhythm disorders and renal dysfunction while evaluating the ways in which the coexistence of renal dysfunction and cardiac arrhythmia influences the management of both.

Inter- and intra-individual concentrations of direct oral anticoagulants: The KIDOAC study

BACKGROUND

Direct oral anticoagulants (DOACs) do not require concentration monitoring. However, whether DOAC concentrations are stable and their variation between and within patients is not well studied.

METHODS

Patients on vitamin K antagonists (VKA) who switched to rivaroxaban, apixaban, or dabigatran were included between 2018 and 2020. Blood was drawn at DOAC trough and peak concentrations at week 0, 2, and 8. Plasma drug concentrations were determined by anti-factor Xa concentrations (rivaroxaban, apixaban) or diluted thrombin time (dabigatran). Inter- and intra-individual variability was assessed by calculating the coefficient of variation (CV). Linear regression models were employed to evaluate associations between DOAC trough concentrations and previous VKA dosage, creatinine clearance, and body mass index (BMI).

RESULTS

One hundred fifty-two patients were included, of whom 96 (63%) were male and with a mean age of 73.9 ± 8.4 years. For the inter-individual variability, the CV ranged between 48% and 81% for trough values and between 25% and 69% for peak values among patients using the recommended DOAC dose. Intra-individual variability was substantially lower, as here the CV ranged between 18% and 33% for trough values and between 15% and 29% for peak values among patients using the recommended DOAC dose. Previous VKA dosage and creatinine clearance were inversely associated with DOAC trough concentrations. No association was found between BMI and DOAC trough concentrations.

CONCLUSION

Inter-individual variability of DOAC concentrations was higher than intra-individual variability. Lower previous VKA dosage and creatinine clearance were associated with higher DOAC trough concentrations. These findings support further study into an optimal target range, in which the risks of both bleeding and thrombosis are minimal.

Direct Oral Anticoagulants for the Treatment of Cancer-Associated Venous Thromboembolism: A Latin American Perspective

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in patients with cancer. On the basis of results from randomized controlled trials, direct oral anticoagulants (DOACs) are now recommended for the treatment of cancer-associated VTE. The decision to use a DOAC requires consideration of bleeding risk, particularly in patients with gastrointestinal (GI) malignancies, the cost-benefit and convenience of oral therapy, and patient preference. While efficacy with apixaban, edoxaban, and rivaroxaban versus dalteparin has been consistent in the treatment of cancer-associated VTE, heterogeneity is evident with respect to major GI bleeding, with an increased risk with edoxaban and rivaroxaban but not apixaban. Although cost and accessibility vary in different countries of Latin America, DOACs should be considered for the long-term treatment of cancer-associated VTE in all patients who are likely to benefit. Apixaban may be the preferred DOAC in patients with GI malignancies and LMWH may be preferred for patients with upper or unresected lower GI tumors. Vitamin K antagonists should only be used for anticoagulation when DOACs and low molecular weight heparin are inaccessible or unsuitable.

Direct oral anticoagulants: A review for the non-specialist

Thrombin inhibitors and direct factor Xa inhibitors represent a major breakthrough in the field of anticoagulation pharmacotherapy. These novel agents have replaced warfarin as the oral anticoagulant of choice in certain indications, as they possess equal or superior efficacy and better safety profiles. They have a quick onset of action, predictable pharmacokinetic properties and minimal drug and food interactions. So they do not require frequent blood monitoring and dose adjustments as with warfarin. Considering all the advantages, there seems to be a rapid increase in the number of patients who are started on these novel anticoagulants. In this review, we highlight the pharmacology of these direct oral anticoagulants and the evidence-based indications for their use. We aim to provide a clinical overview for the non-specialist who may be called upon to manage a patient who is currently on one of these novel anticoagulants.

Can direct oral anticoagulants be used in kidney transplant recipients?

BACKGROUND

Kidney transplant recipients(KTRs) are at an increased risk of venous thromboembolism (VTE) and atrial fibrillation(AF). Direct oral anticoagulants (DOACs) have shown important advantages over vitamin K antagonists; however, in KTRs, concerns regarding interactions and use in severe kidney disease may limit their use. This evaluation describes a large UK kidney transplant center's experience of DOACs in KTRs with CrCl > 15 mL/min.

METHODS

Electronic records were reviewed for all adult KTRs at Manchester University Foundation Trust Hospitals taking DOACs between January 2018 and October 2020 with VTE or AF. The primary outcome was trough and peak DOAC levels within the expected reference ranges and secondary outcomes included bleeding and thrombotic events.

RESULTS

In 31 KTRs taking DOACS, eight patients had a CrCl < 30 mL/min. Overall, 94% (62/66) of DOAC levels were within the recommended ranges. There were no thrombotic events and four bleeding events (two major and two clinically relevant non-major bleeds). The overall bleeding rate was 6.9 per 100 patient-years at risk.

CONCLUSIONS

There was no evidence of a significant interaction of apixaban or rivaroxaban with CNIs based on expected DOAC and CNI levels. Their use was found to be safe and effective with no VTE events and bleeding episodes similar to published trial data.

Review Article: Gastrointestinal Bleeding Risk with Direct Oral Anticoagulants

PURPOSE

Although direct oral anticoagulants (DOACs) are associated with an overall favourable safety profile, the risk of gastrointestinal bleeding with DOACs compared with vitamin K antagonists (VKAs) remains controversial. Accordingly, we aimed to provide a focused overview of the risk of gastrointestinal bleeding associated with dabigatran, rivaroxaban, apixaban and edoxaban and its management.

METHODS

We reviewed published studies reporting on DOACs with gastrointestinal bleeding as an outcome, including randomised controlled trials (RCTs), retrospective database studies and large-scale prospective cohort studies.

RESULTS

Cumulative evidence confirms no notable difference in major gastrointestinal bleeding risk between DOACs and VKAs. Moreover, gastrointestinal bleeding in DOAC-treated patients seems less severe and requires less intensive management. The main cause of upper gastrointestinal bleeding in DOAC-treated patients appears to be gastroduodenal ulcers, whereas lower gastrointestinal bleedings are mainly due to diverticula followed by angiodysplasia and haemorrhoids. The lack of head-to-head RCTs with DOACs precludes drawing conclusions on the DOAC with the lowest gastrointestinal bleeding risk. Prescribing physicians should be aware of risk factors for DOAC-related gastrointestinal bleeding (e.g. age > 65, heavy alcohol use, uncontrolled hypertension, hepatic or renal dysfunction, active cancer, anaemia) and adopt preventive measures accordingly. Management of DOAC-associated major gastrointestinal bleeding involves temporary discontinuation of the DOAC, investigation of the bleeding source and treatment of bleeding with fluid resuscitation combined with transfusion and endoscopic haemostasis.

CONCLUSION

DOACs as a class do not increase the risk of major gastrointestinal bleeding compared to VKAs, which supports their continued use for different anticoagulant indications.

Direct Oral Anticoagulants versus Vitamin K Antagonists in Patients Aged 80 Years and Older

The effectiveness of direct oral anticoagulants (DOAC) is non-inferior to vitamin K antagonists (VKA) to treat atrial fibrillation and venous thromboembolism (VTE). In this cross-sectional study, we compared older persons taking DOACs to those taking VKAs. We included ambulatory individuals ≥80 years, affiliated to Mutualité Sociale Agricole of Burgundy, who were refunded for a medical prescription in September 2017. The demographic conditions, registered chronic diseases (RCD), and number and types of prescribed drugs were compared in the DOAC group and VKA group. Of the 3190 included individuals, 1279 (40%) were prescribed DOACs and 1911 (60%) VKAs. Individuals taking VKAs were older than those taking DOACs (87.11 vs. 86.35 years). In the DOAC group, there were more women (51.92% vs. 48.25%) (p = 0.043), less RCD (89.60% vs. 92.73%) (p = 0.002), less VTE (1.80% vs. 6.59%), less severe heart failure (58.09% vs. 67.87%), less severe hypertension (18.22% vs. 23.60%), less severe kidney diseases (1.49% vs. 3.82%), and fewer drugs per prescription (6.15 vs. 6.66) (p < 0.01 for all). The DOAC group were also less likely to be taking angiotensin receptor blockers (10.79% vs. 13.97%), furosemide (40.81% vs. 49.66%) or digoxin (10.32% vs. 13.66%) than the VKA group (p = 0.009, p < 0.001, and p = 0.005). DOACs were less prescribed than VKAs. Individuals taking VKAs were older and had more severe comorbidities and more drugs per prescription than those taking DOACs.

Development of the Nurses' Intention to Use Deep Vein Thrombosis Preventive Measures Questionnaire

BACKGROUND AND PURPOSE

Deep vein thrombosis (DVT) is a serious condition resulting in poor patient outcomes. Therefore, methods to improve nurses' use of preventive measures for DVT are paramount. The purpose of this study was to develop and validate an instrument that captured nurses' intentions to use DVT preventive measures.

METHODS

Instrument development occurred in several stages stemming from the recommended formatted structure associated with theory of planned behavior (TPB). Content validity was established with a panel of experts, then the instrument was pilot tested with a sample of intensive care unit (ICU) nurses.

RESULTS

The final instrument consisted of four subscales, each subscale was tested with four items by content validity index (CVI) ranging between 0.8 and 1.0, and an overall S-CVI/Ave of 0.93.

CONCLUSIONS

The instrument demonstrated high content validity. Future research will test the instrument for psychometric properties.

The relationship between DOAC levels and clinical outcomes: The measures tell the tale

Direct oral anticoagulants (DOACs) are increasingly used for treatment and prevention of thromboembolic diseases, used in fixed dose regimens. Although their safety and efficacy profiles are considered optimal, clinical events still occur. Given that anticoagulation treatment is a delicate balance between clotting and bleeding, it is possible that an optimal target spot exists where the effect of anticoagulation achieves both the lowest possible risk of bleeding and thrombosis. Other currently available anticoagulants (ie, vitamin K antagonists and heparins) provide important clues for this. If such a target spot exists, tailored DOAC therapy may further benefit patients. This opinion article summarizes the current available evidence that suggests that such a tailored strategy could work. It also describes research suggestions for conducting studies in patient populations such as patients with extremes of body weight or impaired kidney function to evaluate whether tailored treatment with DOACs could lead to better patient outcomes.

Direct Oral Anticoagulant Use in Chronic Kidney Disease and Dialysis Patients With Venous Thromboembolism: A Systematic Review of Thrombosis and Bleeding Outcomes

OBJECTIVE

To evaluate how treatment with DOACs for VTE affects thrombosis and bleeding outcomes compared to warfarin in CKD and dialysis patients.

DATA SOURCES

A literature search was conducted for studies evaluating VTE and bleeding outcomes with DOAC use in CKD and dialysis patients. Searches conducted through EMBASE, MEDLINE/PubMed, Scopus, and Cochrane Central Register of Controlled Trials, from inception to September 22, 2020.

STUDY SELECTION AND DATA EXTRACTION

Randomized controlled trials, cohort studies, and case series with ≥10 patients included.

DATA SYNTHESIS

From 7286 studies, nine studies met inclusion criteria. There was no significant difference between DOACs (dabigatran, rivaroxaban, apixaban) and warfarin for reducing recurrent VTE and bleeding events in moderate CKD patients. The risk of overall major bleeding increased when the degree of kidney impairment increased. There was no significant difference between apixaban and warfarin for VTE outcomes in dialysis patients.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

There continues to be a controversial debate whether it may be more beneficial to use DOACs versus warfarin in CKD/dialysis patients with venous thromboembolism (VTE). The risk vs benefit of using DOACs in the CKD/ESKD population should continue to be evaluated for each individual patient.

CONCLUSION

Apixaban may be used cautiously as an alternative in acute VTE treatment in severe CKD patients. Insufficient evidence is available to suggest the use of dabigatran and rivaroxaban in this patient population. The benefit of using DOACs in this population for VTE treatment should be weighed against the potential bleeding risk in patients with CKD.

Fixed dose rivaroxaban can be used in extremes of bodyweight: A population pharmacokinetic analysis

BACKGROUND

Emerging safety and efficacy data for rivaroxaban suggest traditional therapy and rivaroxaban are comparable in the morbidly obese. However, real-world data that indicate pharmacokinetic (PK) parameters are comparable at the extremes of body size are lacking. The International Society of Thrombosis and Haemostasis Scientific and Standardisation Committee (ISTH SSC) suggests avoiding the use of direct oral anticoagulants (DOACs) in patients weighing >120 kg or with a body mass index >40 kg/m2 and gives no recommendation on the use of DOACs in those <50 kg.

OBJECTIVES

To generate a population PK model to understand the influence of bodyweight on rivaroxaban exposure from clinical practice data.

METHOD

Rivaroxaban plasma concentrations and patient characteristics were collated between 2013 and 2018 at King's College Hospital anticoagulation clinic. A population PK model was developed using a nonlinear mixed effects approach and then used to simulate rivaroxaban concentrations at the extremes of bodyweight.

RESULTS

A robust population PK model derived from 913 patients weighing between 39 kg and 172 kg was developed. The model included data from n = 86 >120 kg, n = 74 BMI >40 kg/m2 , and n = 30 <50 kg. A one-compartment model with between-subject variability on clearance and a proportional error model best described the data. Creatinine clearance calculated by Cockcroft-Gault, with lean bodyweight as the weight descriptor in this equation, was the most significant covariate influencing rivaroxaban exposure.

CONCLUSIONS

Our work demonstrates rivaroxaban can be used at extremes of bodyweight provided renal function is satisfactory. We recommend that the ISTH SSC revises the current guidance with respect to rivaroxaban at extremes of body size.

Increased Incident Ischemic Stroke Risk in Advanced Kidney Disease: A Large-Scale Real-World Data Study

INTRODUCTION

Evidence using real-world data is sparse regarding the effects of oral anticoagulants (OACs) among patients with kidney disease. The aim of this study was to investigate the effects of kidney disease on ischemic stroke (IS) or systemic embolism (SE) among patients taking OAC, using large-scale real-world data in Japan.

METHODS

This was a retrospective cohort study using claims data and health checkup data from health insurance associations in Japan, from January 2005 to June 2017. We enrolled 21,581 patients diagnosed with atrial fibrillation (AF). Of the total population, 11,848 (54.9%) patients were taking OAC. A Cox proportional hazards model was used to examine the effect of kidney disease on IS/SE with or without OAC.

RESULTS

During follow-up, 208 participants who were not taking OAC (mean follow-up 2.6 years) and 200 who were taking OAC (mean follow-up 3.0 years) experienced IS/SE. The % IS/SE incidence rates with and without kidney disease were 2.42/person-year and 0.63/person-year in the total population, 3.66/person-year and 0.76/person-year in the group without OAC use, and 1.52/person-year and 0.55/person-year in patients with OAC use, respectively. Hazard ratios (HRs) and 95% confidence intervals (CIs) of kidney disease for IS/SE were high, irrespective of OAC, even after adjustment: adjusted HR 2.62 (95% CI: 1.72-3.99) without OAC and adjusted HR 2.03 (95% CI: 1.20-3.44) with OAC; p = 0.193 for interaction between no OAC and OAC. Although bleeding risk was also high for kidney disease irrespective of OAC use (HR 2.93 [95% CI: 2.27-3.77] in the total population, HR 3.08 [95% CI: 2.15-4.43] in the group without OAC, and HR 2.73 [95% CI: 1.90-3.91] in the group with OAC use), net clinical benefit indicated that the benefit of OAC use exceeded the risk of bleeding: HR 4.50 (95% CI: 0.76-8.23) among those with kidney disease and HR 0.35 (95% CI: 0.04-0.66) among those without kidney disease.

CONCLUSION

Although we found that OAC use was effective and recommended for patients with AF, advanced kidney disease is still an independent risk factor for IS/SE, even in patients taking OAC. Physicians should be aware of this risk and strictly control modifiable risk factors, regardless of OAC use.

Fixed-dose three-factor prothrombin complex concentrates is safe and effective in warfarin reversal

BACKGROUND

Reversal of warfarin with prothrombin complex concentrates (PCC) is required in cases of significant bleeding or need for urgent surgery. A weight-based regimen is commonly, but a fixed-dose approach is also feasible with clinically equivalent outcomes. The purpose of this audit is to review the clinical and laboratory outcomes of patients treated in our centre where fixed-dose PCC is used for warfarin reversal.

OBJECTIVES

The primary objective was to evaluate the post-reversal INR. Secondary objectives were the proportion of patients requiring repeat PCC and 30-day complication rates (death, haemorrhage and thrombosis). A subgroup analysis was also performed to compare the outcomes of those who received a dose of ≤15 IU/kg (reduced dose) to those who received >15 IU/kg (standard dose).

METHODS

Patients who received three-factor PCC for warfarin reversal between 1st January and 31st December 2016 were identified and analysed. Clinical data and PCC dosages were extracted from electronic patient records.

RESULTS

Total of 144 patients were analysed. The median INR pre-reversal was 3.25 (range 1.4-10), which reduced to 1.5 (0.9-3.0) post-reversal. 87% of patients achieved a post-reversal INR of less than 2 and 55% less than 1.5. Sixteen patients required a repeat dose. Complications occurred in 22 patients (15.3%), which consisted of 15 deaths, 7 thrombosis and 2 haemorrhage. No statistically significant differences in the primary and secondary outcomes were noted between reduced-dose and standard-dose subgroups.

CONCLUSION

Our results support the use of fixed-dose PCC for warfarin reversal in a day-to-day clinical practice in a hospital setting. This article is protected by copyright. All rights reserved.

Severe renal impairment and risk of bleeding during anticoagulation for venous thromboembolism

BACKGROUND

Detection of severe renal impairment in patients with venous thromboembolism (VTE) is mandatory both for selecting anticoagulant therapy and for evaluating major bleeding risk, increased by severe renal impairment.

OBJECTIVES

To determine whether the Cockcroft and Gault (CG) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas identify severe renal impairment in the same VTE patients presenting the same risk of major bleeding.

PATIENTS/METHODS

We compared clinical characteristics and outcomes during the first 3 months of anticoagulation between VTE patients in the RIETE registry with severe renal impairment according to the CG and/or CKD-EPI formula (estimated glomerular filtration rate <30 mL/min and <30 mL/min/1.73 m2 , respectively). The primary outcome was major bleeding.

RESULTS

Up to October 2017, 41 796 patients were included in RIETE. Among the 4676 patients with severe renal impairment according to at least one of the formulas, this was not confirmed by the other formula in 1904 (40.7%). Major bleeding risk was increased in every patient subgroup with severe renal impairment vs patients without this condition (CG or CKD-EPI < 30: odds ratio [OR] = 2.26, 95% confidence interval [CI 2.01-2.53], only CG < 30: OR = 1.72, 95% CI [1.37-2.13], only CKD-EPI < 30: OR = 2.34, 95% CI [1.77-3.05], CG+CKD-EPI < 30: OR = 2.47, 95% CI [2.16-2.83], all vs CG+CKD-EPI > 30).

CONCLUSION

The CG and CKD-EPI formulas identify different subgroups of patients with severe renal impairment, leading to discordant results in 40.7% of these patients. Irrespective of the formula used for their identification, patients with severe renal impairment have a higher risk of major bleeding under anticoagulant therapy.

Health risk of travel for chronic kidney disease patients

The number of people with chronic kidney disease (CKD) has increased and so has their demand for travel. However, the health risk posed by travel in these patients is unclear. Few reports document the travel risk in CKD and dialysis patients. The aim of this study is to summarize the existing evidence of the influence of travel on risks in CKD patients. We aim to describe the association between the impact of travel risks and patients with CKD. A detailed review of recent literature was performed by reviewing PubMed, Google Scholar, and Ichushi Web from the Japan Medical Abstracts Society. Screened involved the following keywords: “traveler's thrombosis,” “venous thromboembolism,” “deep vein thrombosis,” “altitude sickness,” “traveler's diarrhea,” “jet lag syndrome,” “melatonin,” with “chronic kidney disease” only, or/and “dialysis.” We present a narrative review summary of the literature from these screenings. The increased prevalence of thrombosis among travelers with CKD is related to a decrease in the estimated glomerular filtration rate and an increase in urine protein levels. CKD patients who remain at high altitudes are at an increased risk for progression of CKD, altitude sickness, and pulmonary edema. Traveler's diarrhea can become increasingly serious in patients with CKD because of decreased immunity. Microbial substitution colitis is also common in CKD patients. Moreover, time differences and disturbances in the circadian rhythm increase cardiovascular disease events for CKD patients. The existing literature shows that travel-related conditions pose an increased risk for patients with CKD.

The prescription of direct oral anticoagulants in the elderly: An observational study of 19 798 Ambulatory subjects

OBJECTIVE

Direct oral anticoagulants (DOACs) are increasingly prescribed to elderly people, but the epidemiologic data for this population remains scarce. We compared the elderly population taking DOACs and those not taking DOACs (noDOAC).

METHOD

We included individuals over 75 years old, affiliated to Mutualité Sociale Agricole of Burgundy (a French regional health insurance agency), who had been refunded for a prescribed DOAC between 1st and 30th September 2017. The DAOC group (DAOCG) and noDOAC group (noDOACG) were compared in terms of demographic conditions, registered chronic diseases (RCD), and number and types of prescribed drugs. In the DOACG, we compared the type of prescribing physician and laboratory monitoring for novel prescriptions (initial) and prescription refills (≥ 3 months).

RESULTS

Of the 19 798 included patients, 1518 (7.7%) were prescribed DAOCs and 18 280 (92.3%) were not. Mean and median age was 85 years in the 2 groups (DOACG and noDOACG). In the DOACG, there were more men (50% vs 40.2%), more RCD (88.9% vs 68.7%) and more drugs per prescription (6 ± 2.8 vs 5 ± 2.9) (All P < .01). The DOACG also took more antihypertensive drugs. The most commonly prescribed DOACs were apixaban (42.9%) followed by rivaroxaban (38.4%) and dabigatran (18.6%). Complete blood count, serum creatinine and coagulation function tests were requested for 69.4%, 75% and 22.2%, respectively, of patients prescribed DAOCs.

CONCLUSIONS

The DOACG had more RCD and drugs per prescription than the noDOACG; routine laboratory monitoring was insufficient. What's known Platelet aggregation inhibitors (low-dose) are recommended for secondary prevention of cardiovascular events in patients suffering from symptomatic atherosclerosis. The main risk of this treatment is bleeding. What's new A prescription for platelet aggregation inhibitors was found in 34% of geriatric inpatients in this prospective study. Compliance to guidelines was better for symptomatic peripheral artery disease than for primary prevention in accordance with recent publications. Geriatric comorbidities had no impact on the prescription of platelet aggregation inhibitors. Underuse of platelet aggregation inhibitors was observed in 11.3% of cases and overuse in 13.7% of cases.

Role of direct oral anticoagulants in patients with kidney disease

The anticoagulation field is experiencing a renaissance that began with regulatory approval of the direct thrombin inhibitor dabigatran, a direct oral anticoagulant (DOAC), in 2010. The DOAC medication class has rapidly evolved to include the additional approval of 4 direct factor Xa inhibitors. Commensurately, DOAC use has increased and collectively account for the majority of new anticoagulant prescriptions. Despite exclusion of patients with moderate-to-severe kidney disease from most pivotal DOAC trials, DOACs are increasingly used in this setting. An advantage of DOACs is similar or improved antithrombotic efficacy with less bleeding risk when compared with traditional agents. Several post hoc analyses, retrospective studies, claims data studies, and meta-analyses suggest that these benefits extend to patients with kidney disease. However, the lack of randomized controlled trial data in specific kidney disease settings, with their unique pathophysiology, should be a call to action for the kidney community to systematically study these agents, especially because early data suggest that DOACs may pose less risk of anticoagulant-related nephropathy than do vitamin K antagonists. Most DOACs are renally cleared and are significantly protein bound in circulation; thus, the pharmacokinetics of these drugs are influenced by reduced renal function and proteinuria. DOACs are susceptible to altered metabolism by P-glycoprotein inhibitors and inducers, including drugs commonly used for the management of kidney disease comorbidities. We summarize the currently available literature on DOAC use in kidney disease and illustrate knowledge gaps that represent important opportunities for prospective investigation.

Clinical outcomes and treatment patterns among Medicare patients with nonvalvular atrial fibrillation (NVAF) and chronic kidney disease

Background

Patients with nonvalvular atrial fibrillation (NVAF) and chronic kidney disease (CKD) have increased risk of adverse outcomes. This study evaluated treatment with oral anticoagulants and outcomes in elderly NVAF patients with CKD.

Methods

Retrospective observational cohort study of US Medicare fee-for-service patients aged ≥66 years with comorbid CKD (advanced: Stage 4 and higher; less advanced: Stages 1–3) and a new NVAF diagnoses from 2011–2013. All-cause mortality, stroke, major bleeding, and myocardial infarction rates were estimated for 1 year post-NVAF diagnosis. Associations between CKD stage and outcomes were evaluated with multivariate-adjusted Cox regression. We assessed oral anticoagulant (OAC) receipt within 90 days post-NVAF diagnosis and associations between OAC receipt and outcomes.

Results

There were 198,380 eligible patients (79,681 with advanced CKD). After adjustment for age, gender, and comorbidities, advanced CKD was associated with increased mortality (Stage 5 HR 1.47; 95% CI 1.42–1.52), MI (HR 1.48; 95% CI 1.33–1.64), stroke (HR 1.23; 95% CI 1.11–1.37) and major bleed (HR 1.44; 95% CI 1.36–1.53) risks. Among Medicare Part D enrollees who survived ≥90 days post-NVAF diagnosis, 65–71% received no OACs in the first 90 days. Those receiving warfarin (HR 0.73; 95% CI 0.71–0.75) or DOACs (HR 0.52; 95% CI 0.49–0.56) within the first 90 days had reduced mortality in the period 90 days to 1 year following NVAF diagnosis compared to those without.

Conclusion

Elderly NVAF patients with advanced CKD (Stage 4 or higher) had higher mortality risks and serious clinical outcomes than those with less advanced CKD (Stage 1–3). OAC use was low across all CKD stages, but was associated with a lower mortality risk than no OAC use in the first year post-NVAF diagnosis.

Assessing patient preferences for switching from warfarin to direct oral anticoagulants

Warfarin remains the most commonly prescribed oral anticoagulant in the United States, but it has disadvantages such as dietary interactions and frequent laboratory monitoring. Direct oral anticoagulants (DOACs) have been introduced as safer and equally effective alternatives to warfarin. This study assessed patient preference for warfarin or DOAC based on a willingness to pay more for potential DOAC benefits. Current warfarin patients with atrial fibrillation or venous thromboembolism enrolled in the University of Utah Health Thrombosis Service were given a one-time electronic survey that assessed preferences between warfarin and DOACs using scenarios comparing effectiveness, safety, and convenience. When DOACs were preferred, patients were asked how much more they would be willing to pay monthly for the perceived advantages associated with DOACs. With 123 completed surveys, 68% of patients preferred to stay on warfarin. No particular factor influenced patient preference (lack of routine laboratory monitoring, lower risks of major bleeding, and fewer dietary interactions). Reduced stroke risk was associated with the highest value (willing to pay an additional $21). Considering all factors, patients preferring DOACs would pay a median $18 extra per month for the additional benefits. Prior exposure to DOACs was associated with preference for DOACs. Many patients currently taking warfarin preferred to stay on warfarin when given the choice, despite DOAC benefits. Willingness to pay extra for DOAC advantages did not exceed $20 in the majority of survey respondents. Previous DOAC exposure influences patient preference and perceived value for DOACs.