Direct oral anticoagulants in patients with chronic kidney disease: patient selection and special considerations

Dabigatran accumulation in acute kidney injury: is more better than less to prevent bleeding? A case report

Dabigatran is an oral anticoagulant that is mainly renally excreted. Despite its efficacy in preventing thromboembolic events, concerns arise regarding bleeding complications in patients with acute kidney injury. Idarucizumab is its specific antidote and reverses quickly and effectively dabigatran anticoagulation effects in situations of severe bleeding or pending surgical procedures, but its benefit beyond these two indications remains uncertain. We present a case of a woman with atrial fibrillation anticoagulated by dabigatran and admitted with Streptococcus agalactiae meningitis, acute kidney injury and dabigatran accumulation. Idarucizumab was not administered initially as she did not meet its current strict indications. However, subsequently, significant bleeding necessitated its use. A rebound increase in dabigatran concentration was associated with an intracranial hemorrhage, but the combination of additional doses of idarucizumab with hemodialysis lowered the dabigatran concentration and prevented significant rebound increases. Further investigation into the optimal management of dabigatran accumulation and acute kidney injury-associated bleeding is needed to enhance patient outcomes and safety. Early initiation of hemodialysis together with idarucizumab administration may be crucial in preventing life-threatening bleeding events in these patients.

Comparing AGS Beers 2019, STOPP version 2, and EU(7)-PIM list in Portuguese older adults in primary health care

PURPOSE

This study aims to identify PIM prevalence in older adults according to the 2019 Beers criteria, Screening Tool of Older Person's Prescriptions version 2 (STOPP v2) criteria, and the Portuguese EU(7)-PIM list and also to analyze the concordance between these criteria.

METHODS

A retrospective study was conducted among 1200 Portuguese older adults (≥ 65 years old), users of primary health care. Demographic, clinical, and pharmacological data were collected concerning the period between April 2021 and August 2022. A comparative analysis was performed between the three PIM identification criteria, and the concordance was determined according to the Lin concordance correlation coefficient.

RESULTS

The mean age was 76.3 (SD 7.7) years old and 57.6% of the older adults were females. Our findings indicate varying prevalence rates among these criteria with 63.8% (95% CI 61.0-66.6%), 66.8% (95% CI 64.1-69.5%), and 50.1% (95% CI 47.2-53.0%) of the older adults take at least one PIM according to the EU(7)-PIM list, Beers 2019, and STOPP v2 criteria, respectively. The highest prevalence observed was for proton pump inhibitors according to EU(7)-PIM list (30.1%, 95% CI 27.6-32.9) and Beers criteria (30.1%, 95% CI 27.6-32.9) and alprazolam according to STOPP v2 criteria (10.1%, 95% CI 8.4-11.9%). A poor concordance between criteria was observed (< 0.834). The highest concordance coefficient was found between the EU(7)-PIM list and the Beers criteria (0.833), and the lowest between the EU(7)-PIM list and STOPP criteria (0.735).

CONCLUSION

This study reveals varying prevalence rates of PIM in older adults, as assessed by different criteria, and highlights the need for targeted interventions and improved prescribing practices. In the future, studies should focus on the occurrence of negative outcomes in older adults associated with PIM consumption.

Predictors of intracranial hemorrhage in patients with atrial fibrillation treated with oral anticoagulants: Insights from the GARFIELD-AF and ORBIT-AF registries

BACKGROUND

An unmet need exists to reliably predict the risk of intracranial hemorrhage (ICH) in patients with atrial fibrillation (AF) treated with oral anticoagulants (OACs).

HYPOTHESIS

An externally validated model improves ICH risk stratification.

METHODS

Independent factors associated with ICH were identified by Cox proportional hazard modeling, using pooled data from the GARFIELD-AF (Global Anticoagulant Registry in the FIELD-Atrial Fibrillation) and ORBIT-AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) registries. A predictive model was developed and validated by bootstrap sampling and by independent data from the Danish National Patient Register.

RESULTS

In the combined training data set, 284 of 53 878 anticoagulated patients had ICH over a 2-year period (0.31 per 100 person-years; 95% confidence interval [CI]: 0.28-0.35). Independent predictors of ICH included: older age, prior stroke or transient ischemic attack, concomitant antiplatelet (AP) use, and moderate-to-severe chronic kidney disease (CKD). Vitamin K antagonists (VKAs) were associated with a significantly higher risk of ICH compared with non-VKA oral anticoagulants (NOACs) (adjusted hazard ratio: 1.61; 95% CI: 1.25-2.08; p = .0002). The ability of the model to discriminate individuals in the training set with and without ICH was fair (optimism-corrected C-statistic: 0.68; 95% CI: 0.65-0.71) and outperformed three previously published methods. Calibration between predicted and observed ICH probabilities was good in both training and validation data sets.

CONCLUSIONS

Age, prior ischemic events, concomitant AP therapy, and CKD were important risk factors for ICH in anticoagulated AF patients. Moreover, ICH was more frequent in patients receiving VKA compared to NOAC. The new validated model is a step toward mitigating this potentially lethal complication.

Sclerotherapy of lower limb veins: Indications, contraindications and treatment strategies to prevent complications - A consensus document of the International Union of Phlebology-2023

BACKGROUND

Sclerotherapy is a non-invasive procedure commonly used to treat superficial venous disease, vascular malformations and other ectatic vascular lesions. While extremely rare, sclerotherapy may be complicated by serious adverse events.

OBJECTIVES

To categorise contraindications to sclerotherapy based on the available scientific evidence.

METHODS

An international, multi-disciplinary panel of phlebologists reviewed the available scientific evidence and developed consensus where evidence was lacking or limited.

RESULTS

Absolute Contraindications to sclerotherapy where the risk of harm would outweigh any benefits include known hypersensitivity to sclerosing agents; acute venous thromboembolism (VTE); severe neurological or cardiac adverse events complicating a previous sclerotherapy treatment; severe acute systemic illness or infection; and critical limb ischaemia. Relative Contraindications to sclerotherapy where the potential benefits of the proposed treatment would outweigh the risk of harm or the risks may be mitigated by other measures include pregnancy, postpartum and breastfeeding; hypercoagulable states with risk of VTE; risk of neurological adverse events; risk of cardiac adverse events and poorly controlled chronic systemic illness. Conditions and circumstances where Warnings and Precautions should be considered before proceeding with sclerotherapy include risk of cutaneous necrosis or cosmetic complications such as pigmentation and telangiectatic matting; intake of medications such as the oral contraceptive and other exogenous oestrogens, disulfiram and minocycline; and psychosocial factors and psychiatric comorbidities that may increase the risk of adverse events or compromise optimal treatment outcomes.

CONCLUSIONS

Sclerotherapy can achieve safe clinical outcomes provided that (1) patient-related risk factors and in particular all material risks are (1a) adequately identified and the risk benefit ratio is clearly and openly discussed with treatment candidates within a reasonable timeframe prior to the actual procedure; (1b) when an individual is not a suitable candidate for the proposed intervention, conservative treatment options including the option of 'no intervention as a treatment option' are discussed; (1c) complex cases are referred for treatment in controlled and standardised settings and by practitioners with more expertise in the field; (1d) only suitable individuals with no absolute contraindications or those with relative contraindications where the benefits outweigh the risks are offered intervention; (1e) if proceeding with intervention, appropriate prophylactic measures and other risk-mitigating strategies are adopted and appropriate follow-up is organised; and (2) procedure-related risk factors are minimised by ensuring the treating physicians (2a) have adequate training in general phlebology with additional training in duplex ultrasound, procedural phlebology and in particular sclerotherapy; (2b) maintain their knowledge and competency over time and (2c) review and optimise their treatment strategies and techniques on a regular basis to keep up with the ongoing progress in medical technology and contemporary scientific evidence.

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.

Triazol-1-yl Benzamides Promote Anticoagulant Activity via Inhibition of Factor XIIa

BACKGROUND

Human factor XIIa (FXIIa) is a plasma serine protease that plays a significant role in several physiological and pathological processes. Animal models have revealed an important contribution of FXIIa to thromboembolic diseases. Remarkably, animals and patients with FXII deficiency appear to have normal hemostasis. Thus, FXIIa inhibition may serve as a promising therapeutic strategy to attain safer and more effective anticoagulation. Very few small molecule inhibitors of FXIIa have been reported. We synthesized and investigated a focused library of triazol-1-yl benzamide derivatives for FXIIa inhibition.

METHODS

We chemically synthesized, characterized, and investigated a focused library of triazol- 1-yl benzamide derivatives for FXIIa inhibition. Using a standardized chromogenic substrate hydrolysis assay, the derivatives were evaluated for inhibiting human FXIIa. Their selectivity over other clotting factors was also evaluated using the corresponding substrate hydrolysis assays. The best inhibitor affinity to FXIIa was also determined using fluorescence spectroscopy. Effects on the clotting times (prothrombin time (PT) and activated partial thromboplastin time (APTT)) of human plasma were also studied.

RESULTS

We identified a specific derivative (1) as the most potent inhibitor in this series. The inhibitor exhibited nanomolar binding affinity to FXIIa. It also exhibited significant selectivity against several serine proteases. It also selectively doubled the activated partial thromboplastin time of human plasma.

CONCLUSION

Overall, this work puts forward inhibitor 1 as a potent and selective inhibitor of FXIIa for further development as an anticoagulant.

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.

Retrospective Comparison of Patients ≥ 80 Years With Atrial Fibrillation Prescribed Either an FDA-Approved Reduced or Full Dose Direct-Acting Oral Anticoagulant

Direct-acting oral anticoagulants (DOACs) represent the standard for preventing stroke and systemic embolization (SSE) in patients with atrial fibrillation (AF). There is limited information for patients ≥ 80 years. We report a retrospective analysis of AF patients ≥ 80 years prescribed either a US Food and Drug Administration (FDA)-approved reduced (n = 514) or full dose (n = 199) DOAC (Dabigatran, Rivaroxaban, or Apixaban) between January 1st, 2011 (first DOAC commercially available) and May 31st, 2017. The following multivariable differences in baseline characteristics were identified: patients prescribed a reduced dose DOAC were older (p < 0.001), had worse renal function (p = 0.001), were more often prescribed aspirin (p = 0.004) or aspirin and clopidogrel (p < 0.001), and more often had new-onset AF (p = 0.001). SSE and central nervous system (CNS) bleed rates were low and not different (1.02 vs 0 %/yr and 1.45 vs 0.44 %/yr) for the reduced and full dose groups, respectively. For non-CNS bleeds, rates were 10.89 vs 4.15 %/yr (p < 0.001, univariable) for the reduced and full doses, respectively. The mortality rate was 6.24 vs 1.75 %/yr (p = 0.001, univariable) for the reduced and full doses. Unlike the non-CNS bleed rate, mortality rate differences remained significant when adjusted for baseline characteristics. Thus, DOACs in patients ≥ 80 with AF effectively reduce SSE with a low risk of CNS bleeding, independent of DOAC dose. The higher non-CNS bleed rate and not the mortality rate is explained by the higher risk baseline characteristics in the reduced DOAC dose group. Further investigation of the etiology of non-CNS bleeds and mortality is warranted.

Prothrombinase-Induced Clotting Time to Measure Drug Concentrations of Rivaroxaban, Apixaban, and Edoxaban in Clinical Practice: A Cross-Sectional Study

Prothrombinase-induced clotting time (PiCT) is proposed as a rapid and inexpensive laboratory test to measure direct oral anticoagulant (DOAC) drug levels. In a prospective, multicenter cross-sectional study, including 851 patients, we aimed to study the accuracy of PiCT in determining rivaroxaban, apixaban, and edoxaban drug concentrations and assessed whether clinically relevant drug levels could be predicted correctly. Citrated plasma samples were collected, and the Pefakit^® PiCT was utilized. Ultra-high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed to measure drug concentrations. Cut-off levels were established using receiver-operating characteristics curves. We calculated sensitivities and specificities with respect to clinically relevant drug concentrations. Spearman’s correlation coefficient between PiCT and drug concentrations was 0.85 in the case of rivaroxaban (95% CI 0.82, 0.88), 0.66 for apixaban (95% CI 0.60, 0.71), and 0.78 for edoxaban (95% CI 0.65, 0.86). The sensitivity to detect clinically relevant drug concentrations was 85.1% in the case of 30 µg L⁻¹ (95% CI 82.0, 87.7; specificity 77.9; 72.1, 82.7), 85.7% in the case of 50 µg L⁻¹ (82.4, 88.4; specificity 77.3; 72.5, 81.5), and 85.1% in the case of 100 µg L⁻¹ (80.9, 88.4; specificity 73.2%; 69.1, 76.9). In conclusion, the association of PiCT with DOAC concentrations was fair, and the majority of clinically relevant drug concentrations were correctly predicted.

Impact of the COVID-19 pandemic on England's national prescriptions of oral vitamin K antagonist (VKA) and direct-acting oral anticoagulants (DOACs): an interrupted time series analysis (January 2019-February 2021)

BACKGROUND

Direct-acting oral anticoagulants (DOACs) were developed as an alternative to warfarin to treat and prevent thromboembolism, including stroke prevention in non-valvular atrial fibrillation patients. The COVID-19 pandemic could increase the risk of stroke and/or the risk of bleeding in patients due to nonadherence or sub/supra-optimal dosing.

OBJECTIVE

To investigate DOAC prescription trends in England's community settings during the complete first wave of COVID-19 pandemic.

METHODS

Descriptive and interrupted time series (ITS) analyses were conducted to examine the prescription patterns of DOACs (dabigatran, rivaroxaban, apixaban and edoxaban) and warfarin for primary care patients in the English Prescribing Dataset from January 2019 to February 2021, with March 2020 as the cut-off point.

RESULTS

A 19% increase in mean DOAC's accompanied with 20% warfarin prescriptions decline was observed. ITS modelling showed an increase in DOAC prescription volume in March 2020 (+7 million items, p = 0.008). The pre-existing upward trend in DOAC prescriptions slowed during the period (-427,000 items, p = 0.007). Apixaban was the most frequently used DOAC and had the largest step-change in March 2020 (+5 million items, p = 0.010). The mean monthly combined cost of DOACs and warfarin was higher during the period. DOAC prescription trends were consistent across England's regions. Conclusion: The overall oral anticoagulants use in this period was lower than expected, indicating a medical needs gap, possibly due to adherence issues. The potential clinical and logistical consequences warrant further study to identify contributing factors and mitigate avoidable risks.

Sulfonated non-saccharide molecules and human factor XIa: Enzyme inhibition and computational studies

Human factor XIa (FXIa) is a serine protease in the intrinsic coagulation pathway. FXIa has been actively targeted to develop new anticoagulants that are associated with a reduced risk of bleeding. Thousands of FXIa inhibitors have been reported, yet none has reached the clinic thus far. We describe here a novel class of sulfonated molecules that allosterically inhibit FXIa with moderate potency. A library of 18 sulfonated molecules was evaluated for the inhibition of FXIa using a chromogenic substrate hydrolysis assay. Only six molecules inhibited FXIa with IC₅₀ values of 4.6-29.5 μM. Michaelis-Menten kinetics indicated that sulfonated molecules are allosteric inhibitors of FXIa. Inhibition of FXIa by these molecules was reversed by protamine. The molecules also showed moderate anticoagulant effects in human plasma with preference to prolong activated partial thromboplastin time. Their binding to an allosteric site in the catalytic domain of FXIa was modeled to illustrate potential binding mode and potential important Arg/Lys residues. Particularly, inhibitor 16 (IC₅₀  = 4.6 µM) demonstrated good selectivity over a panel of serine proteases including those in the coagulation process. Inhibitor 16 did not significantly compromise the viability of three cell lines. Overall, the reported sulfonated molecules serve as a new platform to design selective, potent, and allosteric inhibitors of FXIa for therapeutic applications.

Evolving concepts in the management of antithrombotic therapy in patients undergoing transcatheter aortic valve implantation

Thromboembolic and bleeding complications negatively impact recovery and survival after transcatheter aortic valve implantation (TAVI). Particularly, there is a considerable risk of ischaemic stroke and vascular access related bleeding, as well as spontaneous gastro-intestinal bleeding. Therefore, benefit and harm of antithrombotic therapy should be carefully balanced. This review summarizes current evidence on peri- and post-procedural antithrombotic treatment. Indeed, in recent years, the management of antithrombotic therapy after TAVI has evolved from intensive, expert opinion-based strategies, towards a deescalated, evidence-based approach. Besides per procedural administration of unfractionated heparin, this encompasses single antiplatelet therapy in patients without a concomitant indication for oral anticoagulation (OAC); and OAC monotherapy in patients with such indication, mainly being atrial fibrillation. Combination therapy should generally be avoided to reduce bleeding risk, except after recent coronary stenting where a period of dual antiplatelet therapy (aspirin plus P2Y12-inhibitor) or P2Y12-inhibitor plus OAC (in patients with an independent indication for OAC) is recommended to prevent stent thrombosis. This new paradigm in which reduced antithrombotic intensity leads to improved patient safety, without a loss of efficacy, may be particularly suitable for elderly and fragile patients. Whether this holds in upcoming populations of younger and lower-risk patients and in specific populations as patients with subclinical valve thrombosis, is yet to be proven. Finally, whether less intensive or alternative approaches should be also applied for the periprocedural management of the antithrombotic therapy, has to be determined by ongoing and future studies.

Lung-kidney interactions and their role in chronic kidney disease-associated pulmonary diseases

Chronic illnesses rarely present in a vacuum, devoid of other complications, and chronic kidney disease is hardly an exception. Comorbidities associated with chronic kidney disease lead to faster disease progression, expedited dialysis dependency, and a higher mortality rate. Although chronic kidney disease is most commonly accompanied by cardiovascular diseases and diabetes, there is clear cross talk between the lungs and kidneys pH balance, phosphate metabolism, and immune system regulation. Our present understanding of the exact underlying mechanisms that contribute to chronic kidney disease-related pulmonary disease is poor. This review summarizes the current research on kidney-pulmonary interorgan cross talk in the context of chronic kidney disease, highlighting various acute and chronic pulmonary diseases that lead to further complications in patient care. Treatment options for patients presenting with chronic kidney disease and lung disease are explored by assessing activated molecular pathways and the body's compensatory response mechanisms following homeostatic imbalance. Understanding the link between the lungs and kidneys will potentially improve health outcomes for patients and guide healthcare professionals to better understand how and when to treat each of the pulmonary comorbidities that can present with chronic kidney disease.

Ethnic Diversity and Warfarin Pharmacogenomics

Warfarin has remained the most commonly prescribed vitamin K oral anticoagulant worldwide since its approval in 1954. Dosing challenges including having a narrow therapeutic window and a wide interpatient variability in dosing requirements have contributed to making it the most studied drug in terms of genotype-phenotype relationships. However, most of these studies have been conducted in Whites or Asians which means the current pharmacogenomics evidence-base does not reflect ethnic diversity. Due to differences in minor allele frequencies of key genetic variants, studies conducted in Whites/Asians may not be applicable to underrepresented populations such as Blacks, Hispanics/Latinos, American Indians/Alaska Natives and Native Hawaiians/other Pacific Islanders. This may exacerbate health inequalities when Whites/Asians have better anticoagulation profiles due to the existence of validated pharmacogenomic dosing algorithms which fail to perform similarly in the underrepresented populations. To examine the extent to which individual races/ethnicities are represented in the existing body of pharmacogenomic evidence, we review evidence pertaining to published pharmacogenomic dosing algorithms, including clinical utility studies, cost-effectiveness studies and clinical implementation guidelines that have been published in the warfarin field.

Factor IX(a) inhibitors: an updated patent review (2003-present)

INTRODUCTION

Anticoagulation with no bleeding complications is the current objective of drug discovery programs in the area of treating and/or preventing thromboembolism. Despite the promises of therapeutics targeting factors XI(a) and XII(a), none has been approved thus far. Clinically used thrombin- and/or factor Xa-based anticoagulants continue to be associated with a significant bleeding risk which limits their safe use in a broad range of thrombotic patients. Research findings in animals and humans indicate that it is possible to target factor IX(a) (FIX(a)) to achieve anticoagulation with a limited risk of bleeding.

AREAS COVERED

A review of patents literature has retrieved >35 patents on the development of molecules targeting FIX(a) since 2003. Small molecules, antibodies, and aptamers have been developed to target FIX(a) to potentially promote effective and safer anticoagulation. Most of these agents are in the pre-clinical development phase and few have been tested in clinical trials.

EXPERT OPINION

FIX(a) system is being considered to develop new anticoagulants with fewer bleeding complications. Our survey indicates that the number of FIX(a)-targeting agents is mediocre. The agents under development are diverse. Although additional development is essential, moving one or more of these agents to the clinic will facilitate achieving better clinical outcomes.

The use of non-vitamin K oral anticoagulants in dialysis patients-A systematic review

Non-vitamin K oral anticoagulants (NOACs) are used for prevention of thromboembolic events, but their use in dialysis patients is debatable. This study investigated the available evidence for the use of NOACs in dialysis patients. Online databases were systematically searched for eligible studies including pharmacokinetic (PK) studies, cohort studies, and randomized control trials (RCTs) comparing NOAC with vitamin K antagonist (VKA) or no anticoagulant treatment. Newcastle Ottawa Scale and Cochrane Risk of bias tool were used for quality assessment. Twenty studies were identified (nine PK studies, two RCTs, and nine cohort studies). Most of the studies investigated apixaban or rivaroxaban. In dialysis patients, less accumulation was reported with apixaban and rivaroxaban compared to dabigatran and edoxaban. PK studies indicate that high dose apixaban or rivaroxaban should be avoided. The two RCTs (rivaroxaban/apixaban vs. VKA) were small and underpowered regarding stroke and bleeding outcomes. Most cohort studies found apixaban superior to VKA, whereas comparison of rivaroxaban with VKA yielded conflicting results. Cohort studies comparing apixaban high dose (5 mg) with low dose (2.5 mg) twice daily suggest a lower risk of stroke with high dose but also a higher risk of bleeding with high dose. Apixaban versus no anticoagulation was compared in one cohort study and did not lower the risk of stroke compared with non-treated regardless of apixaban dosage. Widespread use of NOACs in dialysis patients is limited by adequately sized RCTs. Available evidence suggests a potential for use of apixaban and rivaroxaban in reduced dose.

Utilization of apixaban anti-Xa levels in transition from apixaban to warfarin in a patient with chronic renal dysfunction

DISCLAIMER

In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

The effect of apixaban on anti-factor Xa (anti-Xa) assays and international normalized ratio (INR) complicates transitions between anticoagulant agents. When switching from apixaban to warfarin, the recommendation is to begin both a parenteral anticoagulant and warfarin at the time of the next apixaban dose and to discontinue the parenteral agent when INR is in an acceptable range. This proves challenging in renal dysfunction, as continued presence of apixaban contributes to both a prolonged effect on the INR and continued therapeutic levels of anticoagulation.

SUMMARY

This case describes the transition of apixaban to warfarin in a patient with acute on chronic kidney disease and recent deep vein thrombosis, utilizing chromogenic apixaban anti-Xa assays to assess the level of anticoagulation and avoid unnecessary parenteral anticoagulation.

CONCLUSION

Utilization of apixaban anti-Xa levels aided in the transition from apixaban to warfarin in a patient with chronic renal failure and avoided need for parenteral bridging therapy.

Automated Thrombin Generation Assay for Rivaroxaban, Apixaban, and Edoxaban Measurements

Background: The thrombin generation assay (TG) is a promising approach to measure the degree of anticoagulation in patients treated with direct oral anticoagulants (DOAC). A strong association with plasma drug concentrations would be a meaningful argument for the potential use to monitor DOAC. Objectives: We aimed to study the correlation of TG with rivaroxaban, apixaban, and edoxaban drug concentrations in a large, prospective multicenter cross-sectional study. Methods: Five-hundred and fifty-nine patients were included in nine tertiary hospitals. The Technothrombin® TG was conducted in addition to an anti-Xa assay; LC-MS/MS was performed as the reference standard. Results: Correlation (r_s) between thrombin generation measurements and drug concentrations was -0.72 for peak thrombin generation (95% confidence interval, CI, -0.77, -0.66), -0.55 for area under the curve (AUC; 95% CI -0.61, -0.48), and 0.80 for lag time (95% CI 0.75, 0.84). In contrast, r_s was 0.96 with results of the anti-Xa activity (95% CI 0.95-0.97). Sensitivity with regard to the clinically relevant cut-off value of 50 μgL^-1 was 49% in case of peak thrombin generation (95% CI, 44, 55), 29% in case of AUC (95% CI, 24, 34), and 64% in case of lag time (95% CI, 58, 69). Sensitivity of the anti-Xa assay was 95% (95% CI, 92, 97). Conclusions: The correlation of thrombin generation measurements with DOAC drug concentrations was weak, and clinically relevant drug levels were not predicted correctly. Our results do not support an application of TG in the monitoring of DOAC.

Impaired kidney function at ED admission: a comparison of bleeding complications of patients with different oral anticoagulants

Background

Up to a fourth of patients at emergency department (ED) presentation suffer from acute deterioration of renal function, which is an important risk factor for bleeding events in patients on oral anticoagulation therapy. We hypothesized that outcomes of patients, bleeding characteristics, therapy, and outcome differ between direct oral anticoagulants (DOACs) and vitamin-K antagonists (VKAs).

Methods

All anticoagulated patients older than 17 years with an impaired kidney function treated for an acute haemorrhage in a large Swiss university ED from 01.06.2012 to 01.07.2017 were included in this retrospective cohort study. Patient, treatment, and bleeding characteristics as well as outcomes (length of stay ED, intensive care unit and in-hospital admission, ED resource consumption, in-hospital mortality) were compared between patients on DOAC or VKA anticoagulant.

Results

In total, 158 patients on DOAC and 419 patients on VKA with acute bleeding and impaired renal function were included. The renal function in patients on VKA was significantly worse compared to patients on DOAC (VKA: median 141 μmol/L vs. DOAC 132 μmol/L, p = 0.002). Patients on DOAC presented with a smaller number of intracranial bleeding compared to VKA (14.6% DOAC vs. 22.4% VKA, p = 0.036). DOAC patients needed more emergency endoscopies (15.8% DOAC vs, 9.1% VKA, p = 0.020) but less interventional emergency therapies to stop the bleeding (13.9% DOAC vs. 22.2% VKA, p = 0.027). Investigated outcomes did not differ significantly between the two groups.

Conclusions

DOAC patients were found to have a smaller proportional incidence of intracranial bleedings, needed more emergency endoscopies but less often interventional therapy compared to patients on VKA. Adapted treatment algorithms are a potential target to improve care in patients with DOAC.

Lignosulfonic Acid Sodium Is a Noncompetitive Inhibitor of Human Factor XIa

The anticoagulant activity of lignosulfonic acid sodium (LSAS), a non-saccharide heparin mimetic, was investigated in this study. LSAS is a relatively safe industrial byproduct with similar polyanionic characteristics to that of heparin. Human plasma clotting assays, fibrin polymerization testing, and enzyme inhibition assays were exploited to investigate the anticoagulant activity of LSAS. In normal human plasma, LSAS selectively doubled the activated partial thromboplastin time (APTT) at ~308 µg/mL. Equally, LSAS doubled APTT at ~275 µg/mL in antithrombin-deficient plasma. Yet, LSAS doubled APTT at a higher concentration of 429 µg/mL using factor XI-deficient plasma. LSAS did not affect FXIIIa-mediated fibrin polymerization at 1000 µg/mL. Enzyme assays revealed that LSAS inhibits factor XIa (FXIa) with an IC₅₀ value of ~8 μg/mL. LSAS did not inhibit thrombin, factor IXa, factor Xa, factor XIIIa, chymotrypsin, or trypsin at the highest concentrations tested and demonstrated significant selectivity against factor XIIa and plasmin. In Michaelis–Menten kinetics, LSAS decreased the V_MAX of FXIa hydrolysis of a tripeptide chromogenic substrate without significantly changing its K_M indicating an allosteric inhibition mechanism. The inhibitor also disrupted the generation of FXIa–antithrombin complex, inhibited factor XIIa-mediated and thrombin-mediated activation of the zymogen factor XI to FXIa, and competed with heparin for binding to FXIa. Its action appears to be reversed by protamine sulfate. Structure–activity relationship studies demonstrated the advantageous selectivity and allosteric behavior of LSAS over the acetylated and desulfonated derivatives of LSAS. LSAS is a sulfonated heparin mimetic that demonstrates significant anticoagulant activity in human plasma. Overall, it appears that LSAS is a potent, selective, and allosteric inhibitor of FXIa with significant anticoagulant activity in human plasma. Altogether, this study introduces LSAS as a promising lead for further development as an anticoagulant.

Less is More: Deprescribing Medications in Older Adults with Kidney Disease: A Review

Due to age and impaired kidney function, older adults with kidney disease are at increased risk of medication-related problems and related hospitalizations. One proa ctive approach to minimize this risk is deprescribing. Deprescribing refers to the systematic process of reducing or stopping a medication. Aside from preventing harm, deprescribing can potentially optimize patients' quality of life by aligning medications with their goals of care. For some patients, deprescribing could involve less aggressive management of their diabetes and/or hypertension. In other instances, deprescribing targets may include potentially inappropriate medications that carry greater risk of harm than benefit in older adults, medications that have questionable efficacy, including medications that have varying efficacy by degree of kidney function, and that increase medication regimen complexity. We include a guide for clinicians to utilize in deprescribing, the List, Evaluate, Shared Decision-Making, Support (LESS) framework. The LESS framework provides key considerations at each step of the deprescribing process that can be tailored for the medications and context of individu al patients. Patient characteristics or clinical events that warrant consideration of deprescribing include limited life expectancy, cognitive impairment, and health status changes, such as dialysis initiation or recent hospitalization. We acknowledge patient-, clinician-, and system-level challenges to the depre scribing process. These include patient hesitancy and challenges to discussing goals of care, clinician time constraints and a lack of evidence-based guidelines, and system-level challenges of interoperable electronic health records and limited incentives for deprescribing. However, novel evidence-based tools designed to facilitate deprescribing and future evidence on effectiveness of deprescribing could help mitigate these barriers. This review provides foundational knowledge on deprescribing as an emerging component of clinical practice and research within nephrology.

Direct oral anticoagulants for the treatment of pulmonary embolism in patients with renal impairment

Pulmonary embolism (PE) is associated with adverse outcomes and substantial morbidity and mortality. Patients with PE often have renal impairment because of shared risk factors and close links between the renal and cardiovascular systems. Furthermore, patients with PE and renal impairment are at increased risk of recurrent thrombosis. Therefore, anticoagulation is crucial to treat the acute event, prevent recurrent venous thromboembolism (VTE), and optimize patient outcomes. However, when treated with an anticoagulant, patients with renal impairment also have an elevated risk of bleeding. Direct oral anticoagulants (DOACs) are the first-choice treatment for acute VTE in eligible patients. However, as all DOACs have a degree of renal excretion, the management of anticoagulation therapy can be more complicated in patients with renal impairment. This review provides an overview of the clinical challenges of managing anticoagulation in patients with PE and renal impairment and explores the optimal practice management of this special patient group.

Impact of an integrated medication reconciliation model led by a hospital clinical pharmacist on the reduction of post-discharge unintentional discrepancies

WHAT IS KNOWN AND OBJECTIVE

There is no optimal standardized model in the transfer of care between hospitals and primary healthcare facilities. Transfer of care is a critical point during which unintentional discrepancies, that can jeopardize pharmacotherapy outcomes, can occur. The objective was to determine the effect that an integrated medication reconciliation model has on the reduction of the number of post-discharge unintentional discrepancies.

METHODS

A randomized controlled study was conducted on an elderly patient population. The intervention group of patients received a medication reconciliation model, led entirely by a hospital clinical pharmacist (medication reconciliation at admission, review and optimization of pharmacotherapy during hospitalization, patient education and counselling, medication reconciliation at discharge, medication reconciliation as part of primary health care in collaboration with a primary care physician and a community pharmacist). Unintentional discrepancies were identified by comparing the medications listed on the discharge summary with the first list of medications prescribed and issued at primary care level, immediately after discharge. The main outcome measures were incidence, type and potential severity of post-discharge unintentional discrepancies.

RESULTS AND DISCUSSION

A total of 353 patients were analysed (182 in the intervention and 171 in the control group). The medication reconciliation model, led by a hospital clinical pharmacist, significantly reduced the number of patients with unintentional discrepancies by 57.1% (p < 0.001). The intervention reduced the number of patients with unintentional discrepancies associated with a potential moderate harm by 58.6% (p < 0.001) and those associated with a potential severe harm by 68.6% (p = 0.039). The most common discrepancies were incorrect dosage, drug omission and drug commission. Cardiovascular medications were most commonly involved in unintentional discrepancies.

WHAT IS NEW AND CONCLUSION

The integrated medication reconciliation model, led by a hospital clinical pharmacist in collaboration with all health professionals involved in the patient's pharmacotherapy and treatment, significantly reduced unintentional discrepancies in the transfer of care.

Direct-Acting Oral Anticoagulants in Atrial Fibrillation: What's New in the Literature

Atrial fibrillation (AF) is considered the most common sustained cardiac arrhythmia, and it is associated with a significant risk of adverse events, especially ischemic stroke. Oral anticoagulation is the cornerstone for stroke prevention in AF; for many years, only vitamin K antagonists were used for this purpose, with an absolute risk reduction >60%. However, these agents have limitations, such as narrow therapeutic margins and drug-food and drug-drug interactions. More recently, 4 direct-acting oral anticoagulants (DOACs)-non-vitamin K antagonists-have become available for patients with AF: dabigatran, rivaroxaban, apixaban, and edoxaban. In addition to a comparable efficacy to warfarin in large randomized controlled trials, DOACs were found to promote a lower risk of intracranial bleeding. The strategic dosage and lack of need for periodic prothrombin-time testing make their use attractive, especially for primary or secondary prevention of stroke in older adults. Furthermore, among patients with AF presenting with acute coronary syndrome or undergoing percutaneous coronary intervention, apixaban is associated with a reduction in serious bleeding events when compared with warfarin. On the other hand, there is no evidence of benefit of DOACs in patients with mechanical prosthetic valves or moderate/severe mitral stenosis. Furthermore, the suitability of DOACs in patients with liver disease is still poorly understood, and their safety in patients requiring renal replacement therapy remains uncertain. This review provides an overview of the main trials of DOACs, their pharmacology and safety profile, clinical implications, and best indications in light of the current evidence.

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.

Falls in ED patients: do elderly patients on direct oral anticoagulants bleed less than those on vitamin K antagonists?

Background

Falls from standing are common in the elderly and are associated with a significant risk of bleeding. We have compared the proportional incidence of bleeding complications in patients on either direct oral anticoagulants (DOAC) or vitamin K antagonists (VKA).

Methods

Our retrospective cohort study compared elderly patients (≥65 years) on DOAC or VKA oral anticoagulation who presented at the study site – a Swiss university emergency department (ED) – between 01.06.2012 and 01.07.2017 after a fall. The outcomes were the proportional incidence of any bleeding complication and its components (e.g. intracranial haemorrhage), as well as procedural and clinical parameters (length of hospital stay, admission to intensive care unit, in-hospital-mortality). Uni- and multivariable analyses were used to compare the studied outcomes.

Results

In total, 1447 anticoagulated patients were included – on either VKA (n = 1021) or DOAC (n = 426). There were relatively more bleeding complications in the VKA group (n = 237, 23.2%) than in the DOAC group (n = 69, 16.2%, p = 0.003). The difference persisted in multivariable analysis with 0.7-fold (95% CI: 0.5–0.9, p = 0.014) lower odds for patients under DOAC than under VKA for presenting with any bleeding complications, and 0.6-fold (95% 0.4–0.9, p = 0.013) lower odds for presenting with intracranial haemorrhage. There were no significant differences in the other studied outcomes.

Conclusions

Among elderly, anticoagulated patients who had fallen from standing, those under DOACs had a lower proportional incidence of bleeding complications in general and an even lower incidence of intracranial haemorrhage than in patients under VKAs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00866-6.

Background characteristics and anticoagulant usage patterns of elderly non-valvular atrial fibrillation patients in the ANAFIE registry: a prospective, multicentre, observational cohort study in Japan

OBJECTIVE

To explore anticoagulant usage patterns stratified by stroke and bleeding risk in elderly patients with non-valvular atrial fibrillation (NVAF).

DESIGN

Prospective, multicentre, observational cohort study.

SETTING

The real-world All Nippon AF In the Elderly (ANAFIE) registry.

PARTICIPANTS

Japanese patients aged ≥75 years with NVAF (n=32 726).

OUTCOME MEASURES

The distribution of stroke and bleeding risk scores, and the selection of anticoagulant regimen for patients at high stroke and bleeding risk.

RESULTS

Overall, 18 185 (55.6%) patients had a high risk of stroke (CHADS₂ score ≥3). Of these, 12 561 (38.4% of the total ANAFIE population) had a low bleeding risk (HAS-BLED ≤2) and 5624 (17.2%) had a high bleeding risk (HAS-BLED ≥3). Significant differences were noted between the high versus low bleeding risk groups in sex, height, weight, systolic blood pressure and rates of abnormality of lipid metabolism, gastrointestinal disease, cerebrovascular disorders, chronic kidney disease, angina pectoris, respiratory disease, primary malignant tumour, dementia and fall history within the past year (all p<0.0001). Patients with high stroke and bleeding risks had a lower anticoagulant usage rate versus the low bleeding risk group, and 8.7% and 5.8%, respectively, were not receiving any anticoagulant (p<0.0001). Patients in the high bleeding risk group had a higher usage of warfarin versus the low bleeding risk group (p<0.0001); more patients (14.0%) in the high bleeding risk group receiving warfarin had time in the therapeutic range <40%, versus those in the low bleeding risk group (11.6%, p=0.0146). Direct-acting oral anticoagulants (DOACs) were used less in the high bleeding risk group, without notable differences in the DOAC dose distribution between the two groups.

CONCLUSIONS

In elderly NVAF patients at high stroke risk, significant demographic and clinical differences were observed according to bleeding risk. Administration of low-dose DOACs was frequent, but the dose distribution was unaffected by bleeding risk.

TRIAL REGISTRATION NUMBER

UMIN000024006 (http://www.umin.ac.jp/).

How should we manage hip fracture patients on direct oral anticoagulants?

OBJECTIVE

Currently, there are no national protocols in place for managing hip fracture patients on direct oral anticoagulants (DOACs). Hence, various local management protocols exist. We compared three different local protocols and a control group to assess blood loss and time delay to theatre.

METHODS

Sequential data were collected for 120 hip fracture patients in four groups; wait 24 hours from last dose, wait 48 hours, perform DOAC levels and control.

RESULTS

DOAC use in our hip fracture patients was 14%. Median haemoglobin (Hb) drop between the three protocol groups showed no significant difference (13.5, 21.5 and 16.0 g/L) (Kruskal-Wallis, p=0.9). Median Hb drop in the control group was 16.0 g/L versus 17.5 g/L in the protocol groups combined (Mann Whitney-U, p=0.7). Average Hb drop in the control group was 19.2 g/L and in the protocol groups was 22.1 g/L; a 15% greater blood loss with DOACs. The frequency distribution of blood loss was different between the control and protocol groups, but not between the protocol groups. The highest Hb drop in the control group was 3.4 g/L, while in the protocol groups, it was 7.8 g/L. Median Hb on arrival to hospital was higher in the control group (124 g/L) compared with the three protocol groups (87 g/L) (t-test p<0.0001). Transfusion rates of up to 40% were observed within the DOAC groups compared with zero in the control group.Median time to theatre between the three protocol groups was significantly different at 17.5, 53.3 and 22.5 hours, respectively (Kruskal-Wallis, p<0.0001).

CONCLUSION

DOACs caused increased bleeding and delays to theatre in hip fracture patients, however the largest Hb difference was already apparent on arrival. Subsequent blood loss was minimal on average; a few patients bled heavily. Prolonged waiting made no significant difference to blood loss, but caused delay to theatre leading to financial losses from best practice tariff.

Upper Gastrointestinal Bleeding

Upper gastrointestinal (GI) bleeding is a common reason for hospital admission in older adult patients and carries a high morbidity and mortality if not properly managed. Risk factors include advanced age, Helicobacter pylori infection, medication use, smoking, and history of liver disease. Patients with known or suspected liver disease and suspected variceal bleeding should also receive antibiotics and somatostatin analogues. Risk stratification scores should be used to determine patients at highest risk for further decompensation. Upper endoscopy is both a diagnostic and therapeutic tool used in the management of upper GI bleeding. Endoscopy should be performed within 24 hours of presentation after appropriate resuscitation. Management of anticoagulation in upper GI bleeding largely depends on the indication for anticoagulation, the risk of continued bleeding with continuing the medication, and the risk of thrombosis with discontinuing the medication. A multidisciplinary approach to the decision of anticoagulation continuation is preferred when possible.

Observations on clot properties in atrial fibrillation: Relation to renal function and choice of anticoagulant

INTRODUCTION

Atrial fibrillation (AF) is associated with increased risk of stroke and thromboembolism. Patients with AF have a higher incidence of renal impairment, which may influence the risks of systemic thromboembolism or bleeding. We determined how different oral anticoagulants affect plasma clot properties and whether progressive renal dysfunction affects plasma clot properties in patients on warfarin.

MATERIALS AND METHODS

We studied 257 patients with AF receiving oral anticoagulants. Furthermore, we recruited 192 separate patients with AF on warfarin and divided them in 4 groups based on estimated glomerular filtration rate (eGFR). Platelet poor plasma was prepared and clot formation and fibrinolysis was monitored kinetically up to 1 h.

RESULTS

Rate of clot formation was significantly slower with dabigatran and rivaroxaban. Time between 50% clotting and 50% lysis was prolonged in patients receiving warfarin compared to NOACs. Time to 50% lysis from maximum absorbance was significantly shorter in patients receiving rivaroxaban. Time between 50% clotting and 50% lysis became significantly prolonged with worsening eGFR. Time to 50% lysis from maximum absorbance was prolonged as renal function worsened.

CONCLUSIONS

Compared to warfarin, NOACs differently modulate coagulation and fibrinolysis under ex vivo conditions. Worsening renal function in AF patients on warfarin prolongs fibrinolysis, potentially increasing the risk of thrombosis.

Discovery of Benzyl Tetraphosphonate Derivative as Inhibitor of Human Factor Xia

The inhibition of factor XIa (FXIa) is a trending paradigm for the development of new generations of anticoagulants without a substantial risk of bleeding. In this report, we present the discovery of a benzyl tetra-phosphonate derivative as a potent and selective inhibitor of human FXIa. Biochemical screening of four phosphonate/phosphate derivatives has led to the identification of the molecule that inhibited human FXIa with an IC50 value of ∼7.4 μM and a submaximal efficacy of ∼68 %. The inhibitor was at least 14-fold more selective to FXIa over thrombin, factor IXa, factor Xa, and factor XIIIa. It also inhibited FXIa-mediated activation of factor IX and prolonged the activated partial thromboplastin time of human plasma. In Michaelis-Menten kinetics experiment, inhibitor 1 reduced the VMAX of FXIa hydrolysis of a chromogenic substrate without significantly affecting its KM suggesting an allosteric mechanism of inhibition. The inhibitor also disrupted the formation of FXIa - antithrombin complex and inhibited thrombin-mediated and factor XIIa-mediated formation of FXIa from its zymogen factor XI. Inhibitor 1 has been proposed to bind to or near the heparin/polyphosphate-binding site in the catalytic domain of FXIa. Overall, inhibitor 1 is the first benzyl tetraphosphonate small molecule that allosterically inhibits human FXIa, blocks its physiological function, and prevents its zymogen activation by other clotting factors under in vitro conditions. Thus, we put forward benzyl tetra-phosphonate 1 as a novel lead inhibitor of human FXIa to guide future efforts in the development of allosteric anticoagulants.

The Prescription of Vitamin K Antagonists in a Very Old Population: A Cross-Sectional Study of 8696 Ambulatory Subjects Aged Over 85 Years

We compared very elderly people taking vitamin K antagonists (VKA) and those not taking VKA (noVKA). Individuals were included in the noVKA group if there was no VKA on their reimbursed prescriptions during the study period. We also compared three subgroups, constituted by VKA type (fluindione, warfarin, or acenocoumarol). We included individuals aged over 85 years, affiliated to Mutualité Sociale Agricole of Burgundy, who were refunded for prescribed VKA in September 2017. The VKA and noVKA groups were compared in terms of demographic conditions, registered chronic diseases (RCD), number of drugs per prescription and cardiovascular medications. The three VKA subgroups were compared for the same items plus laboratory monitoring, novel and refill VKA prescriptions, and prescriber specialty. Of the 8696 included individuals, 1157 (13.30%) were prescribed VKA. Mean age was 90 years. The noVKA group had fewer women (53.67 vs 66.08%), more RCD (93.43 vs. 71.96%) and more drugs per prescription (6.65 vs. 5.18) than the VKA group (all p < 0.01). Except for direct oral anticoagulants and platelet aggregation inhibitors, the VKA group took significantly more cardiovascular medications. The most commonly prescribed VKA was fluindione (59.46%). Mean age was higher in the warfarin (90.42) than in the acenocoumarol (89.83) or fluindione (89.71) subgroups (p < 0.01). No differences were observed for sex (women were predominant) or RCD. 13% of subjects in this population had a VKA prescription. Fluindione was the most commonly prescribed VKA.

Antithrombotic Therapy in Patients with Recent Stroke and Atrial Fibrillation

:

Atrial fibrillation (AF) is a common arrhythmia which carries a significant risk of stroke. Secondary prevention, particularly in the acute phase of stroke with anti-thrombotic therapy, has not been validated. The aim of this review is to evaluate the available evidence on the use of antithrombotic therapy in patients with recent stroke who have AF, and suggest a treatment algorithm for the various time points, taking into account both the bleeding and thrombosis risks posed at each stage.

Has the introduction of direct oral anticoagulants (DOACs) in England increased emergency admissions for bleeding conditions? A longitudinal ecological study

OBJECTIVE

There is concern about long-term safety of direct oral coagulants (DOACs) in clinical practice. Our aim was to investigate whether the introduction of DOACs compared with vitamin-K antagonists in England was associated with a change in admissions for bleeding or thromboembolic complications.

SETTING

5508 General practitioner (GP) practices in England between 2011 and 2016.

PARTICIPANTS

All GP practices in England with a registered population size of greater than 1000 that had data for all 6 years.

MAIN OUTCOME MEASURE

The rate of emergency admissions to hospital for bleeding or thromboembolism, per 100 000 population for each GP practice in England.

MAIN EXPOSURE MEASURE

The annual number of DOAC items prescribed for each GP practice population as a proportion of all anticoagulant items prescribed.

DESIGN

This longitudinal ecological study used panel regression models to investigate the association between trends in DOAC prescribing within GP practice populations and trends in emergency admission rates for bleeding and thromboembolic conditions, while controlling for confounders.

RESULTS

For each additional 10% of DOACs prescribed as a proportion of all anticoagulants, there was a 0.9% increase in bleeding complications (rate ratio 1.008 95% CI 1.003 to 1.013). The introduction of DOACs between 2011 and 2016 was associated with additional 4929 (95% CI 2489 to 7370) emergency admissions for bleeding complications. Increased DOAC prescribing was associated with a slight decline in admission for thromboembolic conditions.

CONCLUSION

Our data show that the rapid increase in prescribing of DOACs after changes in National Institute for Health and Care Excellence guidelines in 2014 may have been associated with a higher rate of emergency admissions for bleeding conditions. These consequences need to be considered in assessing the benefits and costs of the widespread use of DOACs.

Incidence of Direct Oral Anticoagulant Prescriptions in Kidney Transplant Recipients in Ontario, Canada

BACKGROUND

Kidney transplant recipients (KTRs) are routinely excluded from direct oral anticoagulant (DOAC) trials. Given the lack of safety and efficacy data in this population, we examined real-world prescribing practices of DOACs in KTRs.

METHODS

We conducted a retrospective cohort study using linked administrative data sets in Ontario, Canada. All adult KTRs (n = 5580) from June 23, 2009, to March 31, 2017, were included. The primary outcomes were the first prescription for a DOAC or warfarin. Patients were censored on graft failure, death, or end of follow-up.

RESULTS

The mean age was 55 (SD, 14) years; 63% were male, and 65% had received a deceased donor kidney. Over a median follow-up of 5.5 and 4.7 years, 224 KTRs (4.0%) and 824 KTRs (14.8%) were prescribed DOACs and warfarin, respectively. The rates of DOAC and warfarin prescriptions were 8.1 and 32.6 per 1000 person-years, respectively. Older age, receipt of a kidney transplant in more recent years, and higher baseline estimated glomerular filtration rate were associated with DOAC prescription compared with warfarin. Patients with multiple comorbidities and a history of deep venous thromboembolism had a lower risk of DOAC prescription compared with warfarin. When examined by era, the incidence rate of both DOAC and warfarin prescriptions increased significantly over time.

CONCLUSIONS

Despite limited safety and efficacy data, DOACs are prescribed to KTRs. However, warfarin still remains more commonly prescribed in this selected patient population. Anticoagulant prescriptions overall are on the rise in KTRs. Further study is needed to determine the safety and efficacy of DOACs in KTRs.

Comparative effectiveness and safety of oral anticoagulants for atrial fibrillation: A retrospective cohort study

Oral anticoagulants (OACs) are high-priority medications, frequently used with clinically important benefit and serious harm. Our objective was to compare the safety and effectiveness of direct-acting oral anticoagulants (DOACs) versus warfarin in a population where anticoagulation management and DOACs were readily available. A retrospective cohort study of all adults living in British Columbia with a diagnosis of atrial fibrillation and a first prescription for an OAC was conducted. Co-primary outcomes were ischemic stroke and systemic embolism, and major bleeding. Secondary outcomes included a net clinical outcome composite and analysis of discontinuation, switching, and key subgroups. We estimated the effects of treatment using time-to-event models with high-dimensional propensity score adjustment to control confounding. After adjustment for prescribing bias, a cohort (n = 20,113, 43.8% female, mean age 72.4 years) with a mean follow-up of 18.1 months showed that patients taking warfarin tended to be poorer, sicker, and less likely to have a cardiologist prescriber. Outcome event rates were not significantly different for DOACs compared to warfarin [adjusted rate ratio of 1.15 (0.91, 1.46) for systemic embolism, 0.94 (0.82, 1.08) for major bleeding, and 0.98 (0.90, 1.06) for net clinical outcome]. Only the effect of age on net clinical outcome met our strict criteria for predicting which group might be superior. Switch of drug class was associated with increased risk of events (p < 0.003). In this population, we found no difference in important clinical outcomes between warfarin and DOACs. Switching compared to not switching was associated with harm.

Stroke Prophylaxis in Patients with Atrial Fibrillation and End-Stage Renal Disease

Atrial fibrillation (AF) is an important comorbidity in patients with end-stage renal disease (ESRD) undergoing dialysis that portends increased health care utilization, morbidity, and mortality in this already high-risk population. Patients with ESRD have a particularly high stroke risk, which is further compounded by AF. However, the role of anticoagulation for stroke prophylaxis in ESRD and AF is debated. The ESRD population presents a unique challenge because of the combination of elevated stroke and bleeding risks. Warfarin has been traditionally used in this population, but it is associated with significant risks of minor and major bleeding, particularly intracranial, thus leading many clinicians to forgo anticoagulation altogether. When anticoagulation is prescribed, rates of adherence and persistence are poor, leaving many patients untreated. The direct oral anticoagulants (DOACs) may offer an alternative to warfarin in ESRD patients, but these agents have not been extensively studied in this population and uncertainties regarding comparative effectiveness (versus warfarin, each other, and no treatment) remain. In this review, we discuss the current evidence on the risk and benefits of anticoagulants in this challenging population and comparisons between warfarin and DOACs, and review future directions including options for non-pharmacologic stroke prevention.

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.

Factor XI(a) inhibitors for thrombosis: an updated patent review (2016-present)

Introduction: Anticoagulation without bleeding is an ideal goal in treating thrombosis, however, this goal has not been achieved. All current anticoagulants are associated with significant bleeding which limits their safe use. Genetic and pharmacological findings indicate that factor XIa is a key player in thrombosis, yet it is a relatively marginal one in hemostasis. Thus, factor XIa and its zymogen offer a unique opportunity to develop anticoagulants with low bleeding risk.Areas covered: A survey of patent literature has retrieved more than 50 patents on the discovery of novel therapeutics targeting factor XI(a) since 2016. Small molecules, monoclonal antibodies, oligonucleotides, and polypeptides have been developed to inhibit factor XI(a). Many inhibitors are in early development and few have been evaluated in clinical trials.Expert opinion: Factor XI(a) is being actively pursued as a drug target for the development of effective and safer anticoagulants. Although many patents claiming factor XI(a) inhibitors were filed prior to 2016, recent literature reveals a moderately declining trend. Nevertheless, more agents have entered different levels of clinical trials. These agents exploit diverse mechanistic strategies for inhibition. Although further development is warranted, reaching one or more of these agents to the clinic will transform the anticoagulation therapy.

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.

Efficacy and Safety of Oral Anticoagulants in Patients With Atrial Fibrillation and Stages 4 or 5 Chronic Kidney Disease

PURPOSE

The aim of this study was to investigate whether oral anticoagulants can provide efficacy and safety profiles better than no anticoagulant in patients with stages 4 or 5 chronic kidney disease and atrial fibrillation.

METHODS

From 2001 to 2017, a cohort of patients with stages 4 or 5 chronic kidney disease and atrial fibrillation based on electronic medical records were selected from Chang Gung Memorial Hospital system in Taiwan. Patients were divided into nonvitamin K antagonist oral anticoagulants (NOACs), warfarin, and nonanticoagulated groups. They were followed from the index date to the occurrence of the study outcomes or for 5 years, whichever occurred first. The outcomes were admissions due to ischemic stroke or systemic embolism or major bleedings. Survival analyses were conducted to estimate the incidence rates of outcomes.

RESULTS

A total of 3771 patients with atrial fibrillation and estimated glomerular filtration rate less than 30 mL/min/1.73m² were enrolled, of whom 2971 were in the nonanticoagulated group, 280 in the NOAC group, and 520 in the warfarin group. About 25% of all subjects (940 patients) were on dialysis. The mean follow-up was 3.2 years. After adjusting for sex, age, comorbidities, and comedication, the warfarin group had a significantly higher risk of ischemic stroke or systemic embolism (adjusted hazard ratio [aHR] 3.1, 95% confidence interval [CI] 2.1-4.6) than the nonanticoagulated group. The NOAC group had a similar risk of ischemic stroke or systemic embolism (aHR 1.1; 95% CI 0.3-3.4) to that of the nonanticoagulated group. Both the warfarin and the NOAC groups had a significantly higher major bleeding risk than the noncoagulated group (aHR 2.8 [95% CI 2.0-3.8] for warfarin; aHR 3.1 [95% CI 1.9-5.2] for NOAC).

CONCLUSION

The use of NOACs or warfarin is not more effective than using no anticoagulants at all in reducing the risk of ischemic stroke or systemic embolism. Both NOACs and warfarin are associated with increased risk of major bleeding. Our results do not support the use of anticoagulants in patients with atrial fibrillation and stages 4-5 chronic kidney disease.

Four-factor Prothrombin Complex Concentrate for the Management of Patients Receiving Direct Oral Activated Factor X Inhibitors

Factor Xa inhibitors prevent thrombosis but are associated with severe or life-threatening bleeding. Here, the authors present data on four-factor prothrombin complex concentrates in management of anticoagulation-associated bleeding and restoring hemostasis, including recent results from the UPRATE study.

Anticoagulation in chronic kidney disease: from guidelines to clinical practice

BACKGROUND

Chronic kidney disease (CKD) is a major global public health problem, being closely connected to cardiovascular disease. CKD involves an elevated thromboembolic risk and requires anticoagulation, but the high rates of hemorrhage render it quite challenging.

HYPOTHESIS

There are no consensus recommendations regarding anticoagulation in CKD. Due to the currently limited data, clinicians need practical clues for monitoring and optimizing the treatment.

METHODS

Based on the available data, this review outlines the benefit-risk ratio of all types of anticoagulants in each stage of CKD and provides practical recommendations for accurate dosage adjustment, reversal of antithrombotic effect, and monitoring of renal function on a regular basis.

RESULTS

Evidence from randomized controlled trials supports the efficient and safe use of warfarin and direct oral anticoagulants (DOACs) in mild and moderate CKD. On the contrary, the data are poor and controversial for advanced stages. DOACs are preferred in CKD stages 1 to 3. In patients with stage 4 CKD, the choice of warfarin vs DOACs will take into consideration the pharmacokinetics of the drugs and patient characteristics. Warfarin remains the first-line treatment in end-stage renal disease, although in this case the decision to use or not to use anticoagulation is strictly individualized. Anticoagulation with heparins is safe in nondialysis-dependent CKD, but remains a challenge in the hemodialysis patients.

CONCLUSIONS

Although there is a need for cardiorenal consensus regarding anticoagulation in CKD, adequate selection of the anticoagulant type and careful monitoring are some extremely useful indications for overcoming management challenges.

The use of anticoagulants in chronic kidney disease: Common point of view of cardiologists and nephrologists

In patients diagnosed with chronic kidney disease (CKD), atrial fibrillation (AF) is associated with an increased risk of thromboembolism and stroke. Moreover, patients with CKD - especially those in end-stage renal disease - also present an increased risk of bleeding. Oral anticoagulation is the most effective form of thromboprophylaxis in patients with AF and an increased risk of stroke. However, the underuse of these drugs was observed, mainly due to safety reasons and restricted evidence on efficacy. Much evidence suggests that non-vitamin K-dependent oral anticoagulant agents significantly reduce the risk of stroke, intracranial hemorrhage, and mortality, with lower to similar major bleeding rates compared with vitamin K antagonists, such as warfarin, in normal renal function subjects. Thus, they are currently recommended for that group of patients. However, their metabolism is largely dependent on the kidneys for elimination, and current knowledge in this area is limited due to patients with a decreased glomerular filtration rate are usually excluded from clinical trials. The present review article focuses on currently available data on oral anticoagulants in patients with moderate to advanced chronic kidney disease and those with end stage renal disease.

Safety of direct oral anticoagulants in real-world clinical practice: translating the trials to everyday clinical management

INTRODUCTION

Direct oral anticoagulants (DOACs) may be regarded as some of the most successful innovations in recent times. These drugs which were specifically developed to overcome the challenges posed by warfarin did just that and in the process, have changed the outlook towards stroke prevention with anticoagulation. The decade of experience with these drugs that has resulted in the availability of large scale data on their safety profile has aided this. Areas covered: This review examines existing real-world studies (RWS) and their interpretation to better appreciate how they either complement or contradict findings from the hallmark trials. Specific focus has been made on the safety of DOACs, on their risks of major bleeding, intra-cranial haemorrhage (ICH), gastro-intestinal (GI) bleeding and all-cause mortality compared to warfarin and each other. DOAC use in the elderly and other sub-groups are briefly discussed. Expert opinion: Results for safety outcomes according to 'real world evidence' (RWE) are in-keeping with randomised controlled trials (RCTs) and currently, all 4 DOACs have been deemed at least as effective as warfarin, while demonstrating superiority in some aspects. While real world studies act as a complementary source of knowledge, traditional RCTs remain the gold standard for determining cause-effect relationships.

Current Management of Cancer-associated Venous Thromboembolism: Focus on Direct Oral Anticoagulants

Cancer-associated venous thromboembolism (CAT) is a common complication associated with high morbidity and mortality. In accordance with major clinical trials comparing low-molecular-weight heparin (LMWH) with a vitamin K antagonist (VKA), LMWH is currently the standard treatment for CAT, owing to its efficacy for thrombosis recurrence and improved safety profile compared to VKA. Over the past few years, direct oral anticoagulants (DOACs) have emerged as potential alternative therapies to LMWH due to their convenient route of administration and predictable pharmacokinetics, but evidence for their use in CAT is inconclusive, as only a small fraction of the study populations in these trials had CAT. Recently, two large head-to-head trials comparing DOACs to LMWH in CAT patients reported comparable efficacies of DOACs with increased bleeding risk. Occasionally, CAT treatment can be challenging due to the heterogeneity of underlying malignancies and comorbidities. Renal insufficiency and gastrointestinal defects are the main obstacles in anticoagulant selection. Careful choice of treatment candidates and proper anticoagulant strategies are critical for the treatment of CAT; hence, more studies are required to address these challenges.