Clinical Pharmacology of Oral Anticoagulants in Patients with Kidney Disease

Transcatheter left atrial appendage occlusion in patients with chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

Chronic kidney disease (CKD) is a risk factor for embolic stroke, and many nonvalvular atrial fibrillation (NVAF) patients have concomitant CKD. Anticoagulation therapy can be challenging in CKD due to increased bleeding risk, and left atrial appendage occlusion (LAAO) may be a promising alternative.

OBJECTIVE

This systematic review aimed to consolidate current evidence on the safety and effectiveness of transcatheter LAAO in patients with CKD and end-stage renal disease (ESRD).

METHODS

Medline, Cochrane, and Embase databases were searched from inception to September 2, 2022. We conducted a meta-analysis if an outcome was evaluated in at least two similar studies.

RESULTS

We included 15 studies with 77,780 total patients. Of the 15 studies, 11 had a cohort design (five prospective and six retrospective), and four were case series. Patients with CKD were older and had a higher prevalence of comorbidities than non-CKD patients. The two groups did not differ in procedural failure rate, vascular complications, or pericardial tamponade. CKD patients exhibited higher odds of in-hospital acute kidney injury (AKI) and bleeding, longer-term bleeding, and mortality than those without CKD. The risk of in-hospital and longer-term cardioembolic events was similar between CKD and non-CKD populations (odds ratio = 1.01 [95% CI 0.70-1.15] and 1.05 [95% CI 0.55-2.00], respectively). Patients with ESRD had higher odds of in-hospital mortality and cardioembolic events than non-ESRD patients, with no differences in risk of pericardial tamponade.

CONCLUSIONS

Based on observational studies, LAAO may be an effective option to prevent cardioembolic events in CKD. However, CKD patients may have higher odds of AKI and in-hospital and long-term bleeding and mortality. The adverse clinical outcomes observed in CKD patients may be attributed to this population's high burden of comorbidities, especially among those with ERSD, rather than the LAAO procedure itself. To ensure maximum clinical benefit, careful patient selection, management, and surveillance involving multidisciplinary teams are essential for CKD patients undergoing LAAO.

Hallmarks for Thrombotic and Hemorrhagic Risks in Chronic Kidney Disease Patients

Chronic kidney disease (CKD) is a global health issue causing a significant health burden. CKD patients develop thrombotic and hemorrhagic complications, and cardiovascular diseases are associated with increased hospitalization and mortality in this population. The hemostatic alterations are multifactorial in these patients; therefore, the results of different studies are varying and controversial. Endothelial and platelet dysfunction, coagulation abnormalities, comorbidities, and hemoincompatibility of the dialysis membranes are major contributors of hypo- and hypercoagulability in CKD patients. Due to the tendency of CKD patients to exhibit a prothrombotic state and bleeding risk, they require personalized clinical assessment to understand the impact of antithrombotic therapy. The evidence of efficacy and safety of antiplatelet and anticoagulant treatments is limited for end-stage renal disease patients due to their exclusion from major randomized clinical trials. Moreover, designing hemocompatible dialyzer membranes could be a suitable approach to reduce platelet activation, coagulopathy, and thrombus formation. This review discusses the molecular mechanisms underlying thrombotic and hemorrhagic risk in patients with CKD, leading to cardiovascular complications in these patients, as well as the evidence and guidance for promising approaches to optimal therapeutic management.

Direct Oral Anticoagulants: Navigating Through Clinical Challenges

PURPOSE

Direct oral anticoagulants (DOACs) have been approved, for over a decade, by both European and American medicine agencies, for treatment and prevention of several cardiovascular conditions. Since then, an increasing amount of data has been added to the medical literature day by day, resulting in a dichotomy in selection of the appropriate agent, dosage, and duration of treatment for special populations with multiple comorbidities. Considering these issues, we have prepared a comprehensive review for the clinical practitioner, to optimize the DOAC utilization in clinical practice.

METHODS

A thorough literature search and review was conducted, concerning mainly the last decade. Our review focused on the current guidelines and the most recently published studies in PubMed, Science Direct Scopus, and Google Scholar to date.

CONCLUSION

The purpose of this study is to provide guidance for healthcare professionals for making proper decisions when confronted with clinical challenges. Nevertheless, further research is required to establish DOAC superiority in complicated cases, where there is clinical uncertainty.

Altered fibrin clot properties are associated with the progression of chronic kidney disease in atrial fibrillation

INTRODUCTION

Formation of denser and resistant to lysis fibrin clot networks has been shown in chronic kidney disease (CKD) and atrial fibrillation (AF). We investigated whether such prothrombotic fibrin clot properties are associated with faster progression of CKD in AF patients.

MATERIAL AND METHODS

We recruited 265 AF patients (men 49.1 %, median age of 64.0 years, median estimated glomerular filtration rate [eGFR] of 77.0 ml/min/1.73 m2), including 137 patients on non-vitamin K antagonist oral anticoagulants (NOACs) (51.7 %) and 109 patients (41.1 %) on vitamin K antagonists (VKAs). At baseline while off anticoagulation, we determined fibrin clot permeability (Ks), and clot lysis time (CLT), along with plasminogen activator inhibitor-1 (PAI-1), endogenous thrombin potential (ETP), and von Willebrand factor (vWF). The kidney function was assessed at baseline and after a median follow-up of 50.0 months.

RESULTS

During follow-up, a median eGFR decreased by 8.0 (5.0-11.0) ml/min/1.73 m2, 1.8 ml/min/1.73 m2/year and this change correlated with age (R = 0.19, P = 0.002), Ks (R = 0.46, P < 0.0001), and CLT (R = -0.17, P = 0.005), but not ETP, fibrinogen, PAI-1 or vWF. A decrease in eGFR was lower in patients who used NOACs at baseline but not in those who started NOACs during follow-up (n = 101) as compared to the remaining patients. On multiple linear regression analysis, adjusted for age and fibrinogen, baseline Ks, eGFR, hypertension, and NOACs use independently predicted a decrease in eGFR.

CONCLUSIONS

This study is the first to show that more compact fibrin clot networks may contribute to faster progression of CKD in AF, indicating novel kidney-related harmful effects of prothrombotic clot properties in humans.

Oral Anticoagulation Use in Individuals With Atrial Fibrillation and Chronic Kidney Disease: A Review

Atrial fibrillation (AF) is highly prevalent in patients with chronic kidney disease (CKD). It is associated with an increased risk of stroke, which increases as kidney function declines. In the general population and in those with a moderate degree of CKD (creatinine clearance 30-50 mL/min), the use of oral anticoagulation to decrease the risk of stroke has been the standard of care based on a favorable risk-benefit profile that had been established in seminal randomized controlled trials. However, evidence regarding the use of oral anticoagulants for stroke prevention is less clear in patients with severe CKD (creatinine clearance <30 mL/min) and those receiving maintenance dialysis, as these individuals were excluded from such large randomized controlled trials. Nevertheless, the direct oral anticoagulants have invariably usurped vitamin K antagonists as the preferred choice for oral anticoagulation among patients with AF across all strata of CKD based on their well-defined safety and efficacy and multiple pharmacokinetic benefits (e.g., less drug-drug interactions). This review summarizes the current literature on the role of oral anticoagulation in the management of AF among patients with CKD and highlights current deficiencies in the evidence base and how to overcome them.

Efficacy and safety of anticoagulant for treatment and prophylaxis of VTE patients with renal insufficiency: a systemic review and meta-analysis

Patients with venous thromboembolism (VTE) comorbid renal insufficiency (RI) are at higher risk of bleeding and thrombosis. Recommendations in guidelines on anticoagulation therapy for those patients remain ambiguous. The goal of this study is to compare the efficacy and safety between different anticoagulant regimens in VTE patients comorbid RI at different stages of treatment and prophylaxis. We performed English-language searches of Pubmed, EMBASE, and Web of Science (inception to Nov 2022). RCTs evaluated anticoagulants for VTE treatment at the acute phase, extension phase, and prophylaxis in patients with RI and reported efficacy and safety outcomes were selected. The methodological quality of the studies was assessed at the outcome level using the risk-of-bias assessment tool developed by the Cochrane Bias Methods Group. A meta-analysis of twenty-five RCTs was conducted, comprising data from twenty-three articles, encompassing a total of 9,680 participants with RI. In the acute phase, the risk of bleeding was increased with novel oral anticoagulants (NOACs) compared to LMWH (RR 1.29, 95% CI 1.04-1.60). For the prophylaxis of VTE, NOACs were associated with an elevated risk of bleeding compared with placebo (RR 1.31, 95%CI 1.02-1.68). In comparison to non-RI patients, both NOACs and vitamin K antagonists (VKA) could increase the risk of bleeding among RI patients (RR 1.45, 95%CI 1.14-1.84 and RR 1.53, 95%CI 1.25-1.88, respectively) during acute phase, while NOACs may increase the incidence of VTE in RI population (RR 1.74, 95%CI 1.29-2.34). RI patients who are under routine anticoagulation have a significantly higher risk of adverse outcomes. LMWH is the most effective and safe option for VTE treatment or prophylaxis in patients with RI.

Anticoagulation in Patients with Chronic Kidney Disease

BACKGROUND

Both atrial fibrillation and venous thromboembolism (VTE) are highly prevalent among patients with chronic kidney disease (CKD). Until recently, warfarin was the most commonly prescribed oral anticoagulant. Direct oral anticoagulants (DOACs) have important advantages and have been shown to be noninferior to warfarin with respect to stroke prevention or recurrent VTE in the general population, with lower bleeding rates. This review article will provide available evidence on the use of DOACs in patients with CKD.

SUMMARY

In post hoc analyses of major randomized studies with DOACs for stroke prevention in atrial fibrillation, in the subgroup of participants with moderate CKD, defined as a creatinine clearance (CrCl) of 30-50 mL/min, dabigatran 150 mg and apixaban were associated with lower rates of stroke and systemic embolism, whereas apixaban and edoxaban were associated with lower bleeding and mortality rates, compared with warfarin. In retrospective observational studies in patients with advanced CKD (defined as a CrCl <30 mL/min) and atrial fibrillation, DOACs had similar efficacy with warfarin with numerically lower bleeding rates. All agents warrant dose adjustment in moderate-to-severe CKD. In patients on maintenance dialysis, the VALKYRIE trial, which was designed initially to study the effect of vitamin K on vascular calcification progression, established superiority for rivaroxaban compared with a vitamin K antagonist (VKA) in the extension phase. Two other clinical trials using apixaban (AXADIA and RENAL-AF) in this population were inconclusive due to recruitment challenges and low event rates. In post hoc analyses of randomized studies with DOACs in patients with VTE, in the subgroup of participants with moderate CKD at baseline, edoxaban was associated with lower rates of recurrent VTE, whereas rivaroxaban and dabigatran were associated with lower and higher bleeding rates, respectively, as compared to warfarin.

KEY MESSAGES

DOACs have revolutionized the management of atrial fibrillation and VTE, and they should be preferred over warfarin in patients with moderate-to-severe CKD with appropriate dose adjustment. Therapeutic drug monitoring with a valid technique may be considered to guide clinical management in individualized cases. Current evidence questions the need for oral anticoagulation in patients on maintenance dialysis with atrial fibrillation as both DOACs and VKAs are associated with high rates of major bleeding.

Pre-hospital use of direct oral anticoagulants agents is associated with a lower risk of major bleeding events in critically ill patients: A single academic center experience

BACKGROUND

The last decade has witnessed significant advancements in direct oral anticoagulants (DOACs), transforming the landscape of anticoagulation therapy. With the uptrend in DOACs use, critical care physicians are encountering more patients with pre-hospital DOACs prescription. Safety and real world outcomes-related data on DOACs use in critically ill patients are scarce.

OBJECTIVE

We assess the risk of major bleeding (MB) events and patient-centered outcomes with pre-hospital use of direct oral anticoagulant agents (DOACs) compared to warfarin therapy.

METHODS

Observational study in a single large academic center from January 1st, 2012, through May 4th, 2018. We included adult critically ill patients with warfarin or one of the DOACs, as active medications at the time of hospital admission. The primary outcome was major bleeding (MB), based on the ISTH criteria RESULTS: 99,481 patients were screened; 558 and 3037 patients were included in the final analysis for the DOAC and warfarin groups, respectively. Multivariable analysis showed that the pre-hospital use of DOACs was associated with lower odds for major bleeding events, GI bleeding, need for endoscopic intervention, hemorrhagic shock, any blood transfusion; but higher odds of intracranial bleeding, as compared to warfarin use. There was no difference in hospital length of stay or ICU-free days.

CONCLUSIONS

Pre-hospital use of DOACs among critically ill patients is associated with lower major bleeding events, GI bleeding, need for endoscopic intervention, and blood transfusion but a higher risk for intracranial bleeding.

Exploring the Link between Cardiorenal and Metabolic Diseases

The close link between metabolic diseases, such as obesity and diabetes mellitus, and cardiorenal disease can be attributed not only to direct risk factors, such as hypertension, but also to the intricate interplay of various pathophysiological processes [...].

Sailing between scylla and charybdis-anticoagulation dilemma in a patient with calciphylaxis and mechanical cardiac valve replacement: a case report and literature review

Calciphylaxis is a rare and life-threatening condition in patients with end-stage kidney disease (ESKD). In this case report, we reported a 72-year-old female who had undergone aortic and mitral mechanical valve replacement 22 years ago due to rheumatic aortic and mitral stenosis. Following the valve replacement, she initiated warfarin treatment. Five years ago, she received a diagnosis of uremia and has since been undergoing regular hemodialysis. Ten months prior to her current admission, she experienced excruciating pain and was diagnosed with calciphylaxis. Additionally, an electrocardiogram revealed atrial fibrillation, while echocardiography indicated that the aortic and mitral mechanical valves were appropriately positioned, with normal perivalvular surroundings and good valve leaflet activity. No noticeable thrombosis was observed in the left atrium or left atrial appendage. Color Doppler imaging showed moderate stenosis in the lower extremity arteries, with no venous thromboembolism present. Extensive eggshell-like calcification within the arterial media was detected. The patient was managed with regular hemodialysis, symptomatic treatments (including anticoagulation and analgesia), and sodium thiosulfate. Unfortunately, symptomatic management provided limited relief, and during the one-month follow-up period, the patient passed away due to septic shock. Currently, there is insufficient conclusive evidence regarding alternative influential anticoagulants or appropriate prosthetic valve selection. For individuals with ESKD receiving maintenance hemodialysis, early identification, diagnosis, and treatment of calciphylaxis are of paramount importance.

Direct oral anti-Xa anticoagulants versus warfarin in newly diagnosed atrial fibrillation and CKD: the Korean National Health Insurance Data

Introduction

Despite the benefits of direct oral anti-Xa anticoagulants (DOACs), the risk-benefit profile of DOAC therapy compared to warfarin therapy in patients with non-valvular atrial fibrillation (AF) and chronic kidney disease (CKD), including end-stage renal disease (ESRD), is uncertain.

Methods

We conducted a retrospective study using the Korea National Health Insurance Database from 2013 to 2018. We evaluated patients with incident non-valvular AF and CKD. The primary and secondary effectiveness outcomes were ischemic stroke and all-cause mortality. The primary safety outcomes included intracranial hemorrhage, gastrointestinal bleeding, and extracranial or unclassified major bleeding.

Results

Among the 1,885 patients evaluated, 970 (51.5%) initiated warfarin therapy, and 915 (48.5%) initiated DOAC therapy. During a mean follow-up period of 23.8 months, there were 293 and 214 cases of ischemic stroke and all-cause death, respectively. Kaplan-Meier survival analysis showed significantly lower all-cause mortality in DOAC users than in warfarin users. In multivariate Cox regression analyses, DOAC therapy had a hazard ratio for all-cause mortality of 0.41 (95% CI, 0.30-0.56; p < 0.001) compared to warfarin therapy. Additionally, DOAC therapy significantly reduced intracranial hemorrhage and gastrointestinal bleeding.

Discussion

Our study demonstrates that DOAC therapy has a better risk-benefit profile than warfarin therapy in patients with AF and CKD. Further well-designed clinical trials are needed to clarify the benefits of DOACs in this patient population.

Kidney function and the comparative effectiveness and safety of direct oral anticoagulants vs. warfarin in adults with atrial fibrillation: a multicenter observational study

AIMS

The aim of this study was to determine the comparative effectiveness and safety of direct oral anticoagulants (DOACs) and warfarin in adults with atrial fibrillation (AF) by level of kidney function.

METHODS AND RESULTS

We pooled findings from five retrospective cohorts (2011-18) across Australia and Canada of adults with; a new dispensation for a DOAC or warfarin, an AF diagnosis, and a measure of baseline estimated glomerular filtration rate (eGFR). The outcomes of interest, within 1 year from the cohort entry date, were: (1) the composite of all-cause death, first hospitalization for ischaemic stroke, or transient ischaemic attack (effectiveness), and (2) first hospitalization for major bleeding defined as an intracranial, upper or lower gastrointestinal, or other bleeding (safety). Cox models were used to examine the association of a DOAC vs. warfarin with outcomes, after 1:1 matching via a propensity score. Kidney function was categorized as eGFR ≥60, 45-59, 30-44, and <30 mL/min/1.73 m2. A total of 74 542 patients were included in the matched analysis. DOAC initiation was associated with greater or similar effectiveness compared with warfarin initiation across all eGFR categories [pooled HRs (95% CIs) for eGFR categories: 0.74(0.69-0.79), 0.76(0.54-1.07), 0.68(0.61-0.75) and 0.86(0.76-0.98)], respectively. DOAC initiation was associated with lower or similar risk of major bleeding than warfarin initiation [pooled HRs (95% CIs): 0.75(0.65-0.86), 0.81(0.65-1.01), 0.82(0.66-1.02), and 0.71(0.52-0.99), respectively). Associations between DOAC initiation, compared with warfarin initiation, and study outcomes were not modified by eGFR category.

CONCLUSION

DOAC use, compared with warfarin use, was associated with a lower or similar risk of all-cause death, ischaemic stroke, and transient ischaemic attack and also a lower or similar risk of major bleeding across all levels of kidney function.

Oral Anticoagulation in Patients With Advanced Chronic Kidney Disease and Atrial Fibrillation: Beyond Anticoagulation

The optimal approach to prevent stroke and systemic embolism in patients with advanced chronic kidney disease (CKD) and atrial fibrillation remains unresolved. We conducted a narrative review to explore areas of uncertainty and opportunities for future research. First, the relationship between atrial fibrillation and stroke is more complex in patients with advanced CKD than in the general population. The currently employed risk stratification tools do not adequately discriminate between patients deriving a net benefit and those suffering a net harm from oral anticoagulation. Anticoagulation initiation should probably be more restrictive than is currently advocated by official guidelines. Recent evidence reveals that the superior benefit-risk profile of non-vitamin K antagonist oral anticoagulants (NOACs) vs vitamin K antagonists (VKAs) observed in the general population and in moderate CKD can be extended to advanced CKD. The NOACs yield better protection against stroke, cause less major bleeding, are associated with less acute kidney injury and a slower decline of CKD, and are associated with a lower incidence of cardiovascular events than VKAs. The VKAs may be harmful in CKD patients, in particular in patients with a high bleeding risk and labile international normalized ratio. The better safety and efficacy of NOACs as opposed to VKAs may be particularly evident in advanced CKD as a result of better on-target anticoagulation with NOACs, harmful off-target vascular effects of VKAs, and beneficial off-target vascular effects of NOACs. The intrinsic vasculoprotective effects of NOACs are supported by animal experimental evidence as well as by findings of large clinical trials and may result in use of NOACs beyond their anticoagulant properties.

Oral Anticoagulation in Patients with Chronic Kidney Disease and Non-Valvular Atrial Fibrillation: The FAERC Study

Atrial fibrillation (AF) is the most common arrhythmia in patients with chronic kidney disease (CKD), and its presence is associated with a higher risk of stroke and mortality.

MATERIAL AND METHODS

The FAERC study performed a retrospective multicentre analysis of historical cohorts in which data were collected from arrhythmia diagnosis onwards.

RESULTS

We analysed a Spanish cohort of 4749 patients with CKD (mean eGFR 33.9 mL/min) followed up in the nephrology clinic, observing a 12.2% prevalence of non-valvular AF. In total, 98.6% of these patients were receiving anticoagulant treatment, mainly with coumarins (79.7%). Using direct-acting oral anticoagulants (DOACs) was associated with fewer cerebrovascular events than using acenocoumarol, but in contrast with other studies, we could not corroborate the association of risk of bleeding, coronary events, or death with a type of anticoagulant prescribed.

CONCLUSIONS

Atrial fibrillation is highly prevalent in renal patients. Direct-acting anticoagulants seem to be associated with fewer ischemic-embolic complications, with no differences in bleeding, coronary events, or mortality rates.

Plasma apixaban levels in Chinese patients with chronic kidney disease-Relationship with renal function and bleeding complications

Introduction: Accumulation of apixaban in plasma is a major concern in patients with chronic kidney disease (CKD). Studies that investigated plasma apixaban level in CKD patients and its association with clinically significant events are scarce. Methods: Patients with CKD Stage 1-4 who were taking apixaban, either 2.5 mg BD or 5 mg BD were recruited. The peak and trough plasma apixaban level were measured after 2 h and 12 h of last dose respectively. The results were correlated with renal function and clinical events during the period of follow-up from 1 January 2018 to 31 October 2021. Results: 141 patients (CKD Stage 1, n = 12; Stage 2, n = 74; Stage 3, n = 48, stage 4, n = 7) were included for analysis. The plasma peak and trough apixaban were significantly higher in patients with CKD stage 3 when compared with those having CKD stage 2 and 1 (peak levels: 223.4 ± 107.8 ng/ml vs. 161.0 ± 55.2 ng/ml vs. 126.6 ± 30.2 ng/ml; trough levels: 118.3 ± 67.9 ng/ml vs. 81.2 ± 33.0 ng/ml vs. 51.9 ± 31.1 ng/ml, p < 0.05 or all) in patients taking 5 mg BD. Plasma trough apixaban level was negatively correlated with eGFR in patients taking 5 mg BD (r ² = -0.174, p < 0.001) and 2.5 mg BD (r ² = -0.215, p < 0.05). The plasma peak and trough apixaban level correlated with PT (r ² = 0.065, p = 0.003 and r ² = 0.096, p < 0.01 respectively). Multivariate analysis showed that plasma trough apixaban levels were associated with the risk of bleeding complications (Odd ratio: 1.011, 95% CI:1.002-1.021, p = 0.023). Conclusion: The plasma apixaban level shows a trend of increase with worsening renal function, and an increase in the plasma apixaban level is suggestive of an increased risk of bleeding complications in patients with CKD. Further large-scale prospective studies are needed to evaluate relationship between plasma apixaban level and renal function as well as safety outcome in CKD patients. Moreover, the role of drug level monitoring should be prospectively evaluated for dosage optimization and the minimization of bleeding risks in CKD patients.

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.

Safety of Non-Vitamin K Antagonist Oral Anticoagulant Treatment in Patients with Chronic Kidney Disease and Kidney Transplant Recipients

The use of novel oral anticoagulants in patients with impaired renal function or undergoing immunosuppressive therapy is limited due to the risk of drug-to-drug interactions and anticoagulation-related adverse events. This article aims to assess the current data on the safety of direct-acting oral anticoagulant-based therapy in the population of kidney transplant recipients and patients with impaired renal function. The most important factors affecting the safety of treatment are the incidence of bleeding events, thromboembolic events, deaths and drug-to-drug interactions. The available data were compared to the findings on warfarin-based anticoagulation. Findings on the use of novel oral anticoagulants in kidney transplant recipients are limited yet promising in terms of safety and efficacy of use. However, current recommendations state that the co-administration of non-vitamin K antagonist oral anticoagulants with several immunosuppressive agents is contraindicated.

Plasma Rivaroxaban Level in Patients With Early Stages of Chronic Kidney Disease-Relationships With Renal Function and Clinical Events

Introduction Drug accumulation of rivaroxaban is a concern in patients with chronic kidney disease (CKD). Data regarding the plasma rivaroxaban levels in early CKD patients and its relationship with clinical events is lacking. Methods Early CKD patients (Stage 1-3) with atrial fibrillation who received rivaroxaban (15 or 20 mg daily) were recruited. Plasma rivaroxaban levels were measured at 2 hours (peak) and 24 hours (trough) after drug administration, and correlated with eGFR and clinically significant events during the follow-up period (1 January 2018 to 31 October 2021). Results Ninety-two patients were included (CKD stage 1 n=10, stage 2 n=53, stage 3 n=29). Plasma trough levels in patients with stage 3 CKD were significantly higher than those with stage 2 and 1 CKD (66.0±34.9 ng/ml vs. 35.7 ± 24.7 ng/ml vs. 34.7 ± 26.2 ng/ml, respectively, p=0.005), and showed inverse relationship with eGFR (r=0.391, p=0.001) in patients receiving 20 mg daily. The plasma trough rivaroxaban level correlated with PT and APTT (r = 0.650 and 0.44, respectively, p<0.001 for both). Plasma trough rivaroxaban level in those with bleeding were higher than those who did not (59.9 ± 35.6 ng/ml vs. 41.1 ± 29.2 ng/ml, p=0.011), and multivariate analysis suggested that plasma trough rivaroxaban level was associated with the rate of bleeding complications (OR: 1.020, 95% CI 1.002-1.038, p=0.028). Conclusion Plasma trough rivaroxaban levels correlated with renal function in early CKD patients, and its measurement may help dosage optimization in patients with renal impairment. Moreover, our data suggests that there may be an association between plasma trough rivaroxaban level and the rate of bleeding complication.

Pharmacologic Agents Used to Reverse the Anticoagulant Effect of Common Anticoagulants

Numerous oral and parenteral anticoagulant drugs are now available for clinical use. Understanding the precise pharmacologic properties of each anticoagulant is imperative for those practitioners who prescribe these drugs, including knowing the current recommendations for reversing the anticoagulant effect of each anticoagulant. This review provides a brief description of the various anticoagulants used today and also discusses the pharmacologic properties of those drugs used to reverse the anticoagulant action of specific anticoagulants.

Temporal trends and in-hospital complications of catheter ablation for atrial fibrillation among patients with moderate and advanced chronic kidney diseases: 2005-2018

INTRODUCTION

Real-world data on atrial fibrillation (AF) ablation among moderate and advanced chronic kidney disease (CKD) patients have so far remained scarce, especially in-hospital AF ablation outcomes.

METHODS

We drew data from the US National Inpatient Sample to identify hospitalized patients who underwent AF ablation between 2005 and 2018, and further stratified by CKD classification. We assessed the trend of AF ablation, as well as its complications.

RESULTS

A total of 152 630 patients who were primarily hospitalized for AF and underwent ablation were estimated. Among these, CKD patients were found in a total of 1509 participants, with 978, 206, and 325 under CKD3, CKD4, and CKD5/ESKD, respectively. There was a significant increment in admission rates for AF ablation in the CKD population across all CKD classifications (p < .001). All CKD patients were statistically older, with higher coexisting comorbidities, while hypertension was found substantially lower than non-CKD patients (p ≤ .001). Importantly, CKD, especially CKD3 and CKD5/ESKD, was significantly associated with an increased risk of total complications, and total bleeding, Neurological complications were found statistically lower in CKD patients (p = .029), and no mortality rates were significantly different (p = .287).

CONCLUSION

Our study observed an increase in admission trends for AF ablation among moderate and advanced CKD patients from 2005 to 2018. CKD was strongly associated with higher procedure-related complications and bleeding, but neurological safety profiles and mortalities rates were nonsignificantly different.

Renal Function Protection as an Important Component of a Comprehensive Approach to the Management of Patients with Atrial Fibrillation

The increase in the life expectancy of the population  is accompanied by an increase in the prevalence of diseases for which old and senile age are risk factors. Atrial fibrillation (AF) and chronic kidney disease (CKD) are two diseases that can coexist in a patient. The risk of ac thromboembolic and hemorrhagic events in this case increases due to the mutual aggravating influence of these diseases. In addition,  these patients have a high incidence of coronary  events, and cardiovascular complications are the main cause of death in patients with AF and CKD. Consequently, such patients require an integrated  approach  to treatment,  and their management is a complex  clinical task. The direct oral anticoagulant rivaroxaban has been most studied in a population  of comorbid  AF and CKD  patients and has proven a high efficacy and safety profile in these patients in randomized controlled trials. In addition,  rivaroxaban has shown  a significant  reduction in the risk of myocardial  infarction  in various patients,  as well as the possibility of preserving renal function to a greater extent compared  with warfarin therapy, and a possible positive effect on reducing  the risk of cognitive impairment.  A single dosing  regimen  can improve adherence  to treatment,  which is one of the key conditions  for achieving  the above effects. Thus, these factors make it possible to achieve comprehensive protection of comorbid  patients with AF and CKD.

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.

Point-of-care testing technologies for the home in chronic kidney disease: a narrative review

Point-of-care testing (POCT) performed by the patient at home, paired with eHealth technologies, offers a wealth of opportunities to develop individualized, empowering clinical pathways. The non-dialysis-dependent chronic kidney disease (CKD) patient who is at risk of or may already be suffering from a number of the associated complications of CKD represents an ideal patient group for the development of such initiatives. The current coronavirus disease 2019 pandemic and drive towards shielding vulnerable individuals have further highlighted the need for home testing pathways. In this narrative review we outline the evidence supporting remote patient management and the various technologies in use in the POCT setting. We then review the devices currently available for use in the home by patients in five key areas of renal medicine: anaemia, biochemical, blood pressure (BP), anticoagulation and diabetes monitoring. Currently there are few devices and little evidence to support the use of home POCT in CKD. While home testing in BP, anticoagulation and diabetes monitoring is relatively well developed, the fields of anaemia and biochemical POCT are still in their infancy. However, patients' attitudes towards eHealth and home POCT are consistently positive and physicians also find this care highly acceptable. The regulatory and translational challenges involved in the development of new home-based care pathways are significant. Pragmatic and adaptable trials of a hybrid effectiveness-implementation design, as well as continued technological POCT device advancement, are required to deliver these innovative new pathways that our patients desire and deserve.

Model-Based Risk Prediction of Rivaroxaban with Amiodarone for Moderate Renal Impaired Elderly Population

PURPOSE

Increased bleeding risk was found associated with concurrent prescription of rivaroxaban and amiodarone. We previously recommended dose adjustment for rivaroxaban utilizing a physiologically based pharmacokinetic (PBPK) modeling approach. Our subsequent in vitro studies discovered the pivotal involvement of human renal organic anion transporter 3 (hOAT3) in the renal secretion of rivaroxaban and the inhibitory potency of amiodarone. This study aimed to redefine the disease-drug-drug interactions (DDDI) between rivaroxaban and amiodarone and update the potential risks.

METHODS

Prospective simulations were conducted with updated PBPK models of rivaroxaban and amiodarone incorporating hOAT3-related parameters.

RESULTS

Simulations to recapitulate previously explored DDDI in renal impairment showed a higher bleeding tendency in all simulation scenarios after integrating hOAT3-mediated clearance into PBPK models. Further sensitivity analysis revealed that both hOAT3 dysfunction and age could affect the extent of DDDI, and age was shown to have a more pivotal role on rivaroxaban in vivo exposure. When amiodarone was prescribed along with our recommended dose reduction of rivaroxaban to 10 mg in moderate renal impaired elderly people, it could result in persistently higher rivaroxaban peak concentrations at a steady state. To better manage the increased bleeding risk among such a vulnerable population, a dose reduction of rivaroxaban to 2.5 mg twice daily resulted in its acceptable in vivo exposure.

CONCLUSION

Close monitoring of bleeding tendency is essential for elderly patients with moderate renal impairment receiving co-prescribed rivaroxaban and amiodarone. Further dose reduction is recommended for rivaroxaban to mitigate this specific DDDI risk.

Extensive skin necrosis in an elderly woman on dabigatran

Dabigatran, a novel oral anticoagulant, is a direct thrombin inhibitor and is being increasingly used owing to the advantage of dosing without the need for laboratory monitoring. While extensive skin necrosis is known to be associated with oral anticoagulants such as warfarin and factor Xa inhibitors, dabigatran toxicity typically manifests with bleeding, especially in the elderly. We describe a 70-year-old woman who was prescribed dabigatran for the treatment of unprovoked deep venous thrombosis. She developed bleeding diathesis along with extensive skin necrosis and acute kidney injury shortly after commencing the drug. Haemodialysis was given in view of dabigatran toxicity and complications of kidney dysfunction which resolved promptly over a week. However, the patient succumbed to severe sepsis from secondary skin infections. It is crucial to closely monitor for signs of dabigatran toxicity, especially in the elderly patients.

Low-Molecular-Weight Heparin Anti-Xa Guided Reversal of Apixaban With Prothrombin Complex Concentrate in a Patient on Hemodialysis

The growing use of oral factor Xa (FXa) inhibitors in patients with chronic kidney disease (CKD), particularly the recent increased use of apixaban in patients with end-stage renal disease (ESRD), has created a new dilemma in the already controversial topic of oral FXa inhibitor reversal. With the limited availability of anti-Xa levels specific to oral FXa inhibitors and even scarcer availability of reversal data for patients on these agents with ESRD, ensuring adequate reversal is currently often solely guided by repeat imaging and changes in clinical status. Low molecular weight heparin (LMWH) anti-Xa levels have been used as a more commonly accessible test to guide the need for and efficacy of reversal of oral FXa inhibitors in patients with normal renal function. However, evidence supporting this technique is again lacking in patients with renal dysfunction. This case report focuses on the use of LMWH anti-Xa levels to guide reversal of apixaban in a patient with ESRD on hemodialysis and correlation of those levels to the patient's clinical status.

Comparing total medical expenditure between patients receiving direct oral anticoagulants vs warfarin for the treatment of atrial fibrillation: evidence from VA-Medicare dual enrollees

BACKGROUND: Direct oral anticoagulants (DOACs) are an alternative to warfarin for treatment of atrial fibrillation (AF). Evidence demonstrating the efficacy and safety of DOACs has primarily been from clinical trial settings. The real-world effectiveness of DOACs in specific nontrial populations that differ in age, comorbidity burden, and socioeconomic status is unclear. OBJECTIVE: To compare total downstream medical expenditure between AF patients treated with warfarin and DOACs dually enrolled in the Veterans Affairs (VA) Healthcare System and fee-for-service Medicare. METHODS: This was an exploratory treatment effectiveness study that analyzed VA administrative data and Medicare claims. We examined patients with an incident diagnosis for AF and initiated warfarin or DOAC treatment between 2012 and 2015. The primary outcome was total medical expenditure over 3 years following treatment initiation. To address potential informative censoring, we applied a multipart estimator that extends traditional 2-part models to separate differences between groups due to survival and cost accumulation effects. Inverse probability weighting was applied to address potential treatment selection bias. RESULTS: We identified 31,276 and 17,021 patients receiving warfarin and DOACs, respectively. Mean unadjusted (SD) expenditure was higher for warfarin ($56,265 [$96,666]) compared with DOAC patients ($32,736 [$52,470]). Compared with patients receiving DOACs, adjusted 3-year expenditure was $25,688 (P < 0.001) higher for patients receiving warfarin. CONCLUSIONS: VA patients with AF initiating warfarin incurred markedly higher downstream expenditure compared with similar patients receiving DOACs. The benefits of DOACs found in previous clinical trials were present in this population, suggesting that these DOACs may be the preferred option for treatment of AF in older VA patients. DISCLOSURES: This study was funded by a VA Health Services Research and Development Investigator Initiated Research Award (IIR 15-139). Support for VA/CMS data was provided by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development, Health Services Research and Development, VA Information Resource Center (Project Numbers SDR 02-237 and 98-004). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs, the University of Washington, Northeastern University, and Boston University. The authors declare no conflicts of interest. This research includes data obtained from the VHA Office of Performance Measurement (17API2), which resides within the Office of Analytics and Performance Integration (API), under the Office of Quality and Patient Safety (QPS; formerly known as RAPID). An oral presentation documenting a subset of the findings from this study was presented at the 2020 AcademyHealth Annual Research Meeting, delivered virtually on July 29, 2020.

Oral Anticoagulant Treatment in Patients with Atrial Fibrillation and Chronic Kidney Disease

Over the past few decades, a series of innovative medicines have been developed in order to optimize anticoagulation therapy for atrial fibrillation (AF). As a result, a number of nonvitamin K antagonist oral anticoagulants (NOAC) that directly target the enzymatic activity of factor II and factor Xa have been successfully licensed providing a more predictable effect and better safety profile compared to conventional anticoagulants (heparins and vitamin K antagonists (VKAs)). However, comparative efficacy and safety data is limited in patients with advanced chronic kidney disease (i.e., CKD stage 4/5 and end stage renal disease) because patients with estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m² were actively excluded from landmark trials, thus representing a major clinical limitation for the currently available agents. However, the renal function of AF patients can be altered over time. On the other hand, patients with CKD have an increased risk of developing AF. This review article will provide an overview of current concepts and recent evidence guiding the clinical use of NOACs in patients with CKD requiring chronic anticoagulation, and the associated risks and benefits of treatment in this specific patient population.

Integrated Care in Atrial Fibrillation: A Road Map to the Future

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice with an epidemiological coupling appreciated with advancing age, cardiometabolic risk factors, and structural heart disease. This has resulted in a significant public health burden over the years, evident through increasing rates of hospitalization and AF-related clinical encounters. The resultant gap in health care outcomes is largely twinned with suboptimal rates of anticoagulation prescription and adherence, deficits in symptom identification and management, and insufficient comorbid cardiovascular risk factor investigation and modification. In view of these shortfalls in care, the establishment of integrated chronic care models serves as a road map to best clinical practice. The expansion of integrated chronic care programs, which include multidisciplinary team care, nurse-led AF clinics, and use of telemedicine, are expected to improve AF-related outcomes in the coming years. This review will delve into current gaps in AF care and the role of integrated chronic care models in bridging fragmentations in its management.

Anticoagulation Management In Hemodialysis Patients With Atrial Fibrillation: Evidence And Opinion

In the absence of robust evidence to guide clinical decision making, the optimal approach to prevent stroke and systemic embolism in hemodialysis patients with atrial fibrillation (AF) remains moot. In this position paper, studies on oral anticoagulation in hemodialysis patients with AF are highlighted, followed by an evidence-based conclusion, a critical analysis to identify sources of bias, and practical opinion-based suggestions on how to manage anticoagulation in this specific population. It remains unclear whether AF is a true risk factor for embolic stroke in hemodialysis. The currently employed cutoff values for the CHA2DS2-VASc score do not adequately discriminate dialysis patients deriving a net benefit from those suffering a net harm from oral anticoagulation. Anticoagulation initiation should probably be more restrictive than currently advocated by official guidelines. Recent evidence reveals that the superior benefit-risk profile of direct oral anticoagulants (DOAC) versus vitamin K antagonists (VKA) observed in the general population and in moderate chronic kidney disease can be extended to the hemodialysis population. VKA may be especially harmful in dialysis patients and should therefore be avoided, in particular in patients with a high bleeding risk and labile international normalized ratio. Dose-finding studies of DOAC suggest that rivaroxaban 10 mg daily and apixaban 2.5 mg twice daily are appropriate choices in dialysis patients. Combined treatment of oral anticoagulants and antiplatelet agents should be reserved for strong indications and limited in time. Left atrial appendage occlusion is a potential attractive solution to reduce the risk of stroke without increasing bleeding propensity, but has not been properly studied in dialysis patients.

Review of Medical Therapies for the Management of Pulmonary Embolism

Traditionally, the management of patients with pulmonary embolism has been accomplished with anticoagulant treatment with parenteral heparins and oral vitamin K antagonists. Although the administration of heparins and oral vitamin K antagonists still plays a role in pulmonary embolism management, the use of these therapies are limited due to other options now available. This is due to their toxicity profile, clearance limitations, and many interactions with other medications and nutrients. The emergence of direct oral anticoagulation therapies has led to more options now being available to manage pulmonary embolism in inpatient and outpatient settings conveniently. These oral therapeutic options have opened up opportunities for safe and effective pulmonary embolism management, as more evidence and research is now available about reversal agents and monitoring parameters. The evolution of the pharmacological management of pulmonary embolism has provided us with better understanding regarding the selection of anticoagulants. There is also a better understanding and employment of anticoagulants in pulmonary embolism in special populations, such as patients with liver failure, renal failure, malignancy, and COVID-19.

Rivaroxaban: Expanded Role in Cardiovascular Disease Management-A Literature Review

Direct oral anticoagulants (DOACs) are widely used for the prevention of stroke in nonvalvular atrial fibrillation, treatment of deep venous thrombosis and pulmonary embolism, and as prophylaxis after hip and knee surgery after approval by the Food and Drug Administration. In the last decade, DOACs were studied for various indications; this review is focused on rivaroxaban, a factor Xa inhibitor, which is used in an expanded evidence-based fashion for coronary artery disease, peripheral artery disease, heart failure, malignancy, and prophylaxis of deep venous thrombosis in acute medical illnesses.

A case-control study indicates that coagulation imbalance is associated with arteriosclerosis and markers of endothelial dysfunction in kidney failure

Endothelial dysfunction, one of many causes of arterial changes in end-stage kidney disease (kidney failure), is a likely link between early vascular aging and the risk of thrombosis or bleeding in this condition. To evaluate this, we compared links between arterial stiffness and endothelial/coagulation factors in 55 patients receiving hemodialysis therapy and 57 age-/sex-matched control individuals. Arterial stiffness was assessed from carotid-femoral pulse wave velocity, and coagulation status from the endogenous thrombin generating potential. Markers of endothelial dysfunction (von Willebrand factor, tissue factor pathway inhibitor), neutrophil extracellular traps and tissue factor-positive extracellular vesicles were higher in patients with kidney failure. Prothrombin fragments 1 and 2, and D-dimer markers of in vivo coagulation activation were also higher. However, in vitro in the presence of platelets, endogenous thrombin generating potential was lower and its downregulation by activated protein C impaired. Antiplatelet drugs did not affect these parameters. In multiple regression analysis, prothrombin fragments 1 and 2, D-dimer, factor VIII and monocyte-derived tissue factor-positive extracellular vesicles correlated with higher carotid-femoral pulse wave velocity. In patients with kidney failure, in vivo hypercoagulability occurred with reduced thrombin generation in platelet-rich plasma, likely explaining the opposing thrombotic and bleeding tendencies in patients with kidney failure. Importantly, arteriosclerosis is more closely related to a prothrombotic state. Thus, coagulation changes plus arterial stiffness highlight a major therapeutic challenge for anticoagulant and antiplatelet drug use.

Anticoagulation in hemodialysis: A narrative review

Systemic anticoagulation in maintenance hemodialysis (HD) has historically been considered necessary to maintain the extracorporeal circuit (ECC) and preserve dialysis efficiency. Unfractionated heparin (UFH) is the most commonly used anticoagulant due to low cost and staff familiarity. Despite widespread use, there is little standardization of heparin dosing protocols in the United States. Although the complication rates with UFH are low for the general population, certain contraindications have led to exploration in alternative anticoagulants in patients with end-stage kidney disease (ESKD). Here we review the current evidence regarding heparin dosing protocols, complications associated with heparin use, and discuss alternatives to UFH including anticoagulant-free routine HD.

Appropriate Dosing Regimens of Non-Vitamin K Antagonist Oral Anticoagulants for Treatment of Patients With Non-Valvular Atrial Fibrillation: An Evidence-Based Consideration

Patients with non-valvular atrial fibrillation (NVAF) exhibit a high risk of stroke, which is associated with high mortality. Thus, stroke prevention is crucial for the overall management of NVAF. Two categories of drugs, vitamin K antagonist warfarin and non-vitamin K antagonist oral anticoagulants (NOACs), are clinically used to prevent NVAF-related stroke. In some circumstances, NOACs are superior to warfarin. However, NOACs selection for NVAF patients is affected by many factors, including individual patient characteristics, comorbidities, risk factors, or laboratory variables. This article summarizes the discrepancy in NOACs management with emphasis on the dosing regimens and influencing factors, such as stroke risk, age, body weight, renal function, gastrointestinal bleeding (GIB) risk, and combination of antiplatelet therapy, in order to identify individual groups with particular clinical characteristics who may obtain more benefit from a certain dosing regimen of NOACs. Determination of a particular subset of patient populations for the appropriate dose regimen of NOACs will help to achieve desired clinical outcomes. Furthermore, to compensate clinical evidence, we should place more emphasis on the findings of current clinical trials and supplement real-world data.

Oral Anticoagulation for Atrial Fibrillation Thromboembolism Prophylaxis in the Chronic Kidney Disease Population: the State of the Art in 2019

Atrial fibrillation (AF) is the most common cardiac rhythm disturbance and is associated with increased risk of thromboembolism. Oral anticoagulants are effective at reducing rates of thromboembolism in patients with AF in the general population. Patients with AF and concurrent chronic kidney disease (CKD) have higher risk of thromboembolism and bleeding compared with patients with normal renal function. Among moderate CKD and end-stage renal disease (ESRD) patients on chronic dialysis, the use of oral anticoagulants is controversial. Use of warfarin, while beneficial in non-CKD patients, raises a number of concerns such as increased bleeding risk, labile anticoagulant effect, and calciphylaxis, especially in the ESRD population. The newer direct oral anticoagulant (DOAC) agents have demonstrated comparable efficacy and improved safety profiles compared with coumadin but are not as well studied in the CKD population. This review highlights the efficacy and safety of coumadin and the DOACs for thromboembolism prophylaxis in non-valvular AF patients with CKD.

Updates in periprocedural management of direct oral anticoagulants

PURPOSE OF REVIEW

As the prevalence of patients on antithrombotics is increasing, anesthesiologists must have a firm understanding of these medications and considerations for their periprocedural management. This review details up-to-date periprocedural management of direct oral anticoagulants (DOACs).

RECENT FINDINGS

DOACs have favorable pharmacokinetics including quick onset of action and short half-lives. Periprocedural management of DOACs relies heavily on drug half-life as well as procedural risk of bleeding. Other than a few exceptions, the American College of Cardiologists generally recommends complete clearance of oral anticoagulants prior to high-risk bleeding procedures and partial clearance prior to low-risk bleeding procedures. Procedures with little to no clinical risk of bleeding can be performed without any drug interruption or during trough levels. Exceptions to periprocedural DOAC management pertain to electrophysiology procedures.

SUMMARY

With the exception of no clinically relevant bleeding risk or certain electrophysiology procedures, DOACs should be discontinued periprocedurally in accordance with bleeding risks and drug's half-life. Bridging is generally not recommended for DOACs.

Safety and effectiveness of non-vitamin K oral anticoagulants versus warfarin in real-world patients with non-valvular atrial fibrillation: a retrospective analysis of contemporary Japanese administrative claims data

Objective

To assess the safety (ie, risk of bleeding) and effectiveness (ie, risk of stroke/systemic embolism (SE)) separately for four non-vitamin K oral anticoagulants (NOACs; apixaban, dabigatran, edoxaban and rivaroxaban) versus warfarin in Japanese patients with non-valvular atrial fibrillation (NVAF), including those at high risk of bleeding and treated with reduced doses of NOACs.

Methods

We conducted a retrospective analysis of electronic health records and claims data from 372 acute care hospitals in Japan for patients with NVAF newly initiated on NOACs or warfarin. Baseline characteristics were balanced using inverse probability of treatment weighting with stabilised weights (s-IPTW). Bleeding risk and stroke/SE risk were expressed as HRs with 95% CIs. Two sensitivity analyses were conducted.

Results

A total of 73 989 patients were eligible for analysis. Notably, 52.8%-81.9% of patients received reduced doses of NOACs. After applying s-IPTW, patient characteristics were well balanced across warfarin/NOAC cohorts. The mean within-cohort age, CHADS₂ score and CHA₂DS₂-VASc score were 76 years, 2.2-2.3 and 3.8, respectively. In all age categories, the majority of the HRs for major bleeding, any bleeding and stroke/SE were equal to or below 1 for all NOACs versus warfarin. Apixaban was the only NOAC associated with a significantly lower risk of any bleeding. There was a trend towards increased risk reduction with NOACs versus warfarin in patients with body weight ≥60 kg. In patients with renal disease, the HRs for apixaban versus warfarin were below 1 for major bleeding, any bleeding and stroke/SE, with statistical significance observed for the risk reduction in stroke/SE versus warfarin. In the sensitivity analysis, there were no large differences in HRs between the two observational periods.

Conclusions

In patients with NVAF primarily treated with reduced-dose NOACs, the risks of stroke/SE and major bleeding were significantly lower with NOACs versus warfarin.

Anticoagulant strategies for the patient with chronic kidney disease

Chronic kidney disease (CKD) is a global health problem affecting up to 14% of the adult population in developed countries. On the basis of current guidelines, patients with CKD will often fulfil criteria for both short-term and long-term anticoagulation. Paradoxically, patients with CKD are not only at a higher risk of thrombosis, they are also at increased risk of bleeding. Furthermore, the pharmacokinetics and pharmacodynamics of many anticoagulant therapies are significantly affected by renal dysfunction. In addition, patients with advanced CKD are often systematically excluded from major clinical trials. As such, the decision on whether to anticoagulate or not, and if so with what agent, poses significant challenges. A solid understanding of the condition in question and the available treatments is required to make an informed judgement call. An in-depth appreciation of the advantages and disadvantages of the currently available anticoagulants is a key element in the decision-making process.

Safety and Efficacy of Direct Oral Anticoagulants for Atrial Fibrillation in Patients with Renal Impairment

Direct oral anticoagulants (DOACs) are gaining popularity for patients with nonvalvular atrial fibrillation (AF) for stroke prevention. Less bleeding risk with comparable stroke prevention compared to warfarin was shown. DOACs have predictable anticoagulant effects, infrequent monitoring requirements and less drug-food interactions compared to warfarin. However, safety and efficacy data of DOACs in patients with chronic kidney disease (CKD) are limited. This is a retrospective study to evaluate thromboembolic and bleeding events in patients with AF (with/without CKD) in October 2010 and July 2017. A total of 495 patients were included and only 150 patients had CKD. Our study found that patients with renal impairment on a DOAC do not have a higher incidence of bleeding events. It showed significant increase in thromboembolic events in CKD patients with dabigatran compared to CKD patients with apixaban with odds ratio of 6.58 (95%CI 1.35-32.02, p = 0.02).

Edoxaban Exerts Antioxidant Effects Through FXa Inhibition and Direct Radical-Scavenging Activity

The interplay between oxidative stress, inflammation, and tissue fibrosis leads to the progression of chronic kidney disease (CKD). Edoxaban, an activated blood coagulation factor Xa (FXa) inhibitor, ameliorates kidney disease by suppressing inflammation and tissue fibrosis in animal models. Interestingly, rivaroxaban, another FXa inhibitor, suppresses oxidative stress induced by FXa. Thus, FXa inhibitors could be multitargeted drugs for the three aforementioned risk factors for the progression of CKD. However, the exact mechanism responsible for eliciting the antioxidant effect of FXa inhibitors remains unclear. In this study, the antioxidant effect of edoxaban was evaluated. First, the intracellular antioxidant properties of edoxaban were evaluated using human proximal tubular cells (HK-2 cells). Next, direct radical scavenging activity was measured using the electron spin resonance and fluorescence analysis methods. Results show that edoxaban exhibited antioxidant effects on oxidative stress induced by FXa, indoxyl sulfate, and angiotensin II in HK-2 cells, as well as the FXa inhibitory activity, was involved in part of the antioxidant mechanism. Moreover, edoxaban exerted its antioxidative effect through its structure-specific direct radical scavenging activity. Edoxaban exerts antioxidant effects by inhibiting FXa and through direct radical-scavenging activity, and thus, may serve as multitargeted drugs for the three primary risk factors associated with progression of CKD.

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.

Anticoagulation in Patients With Advanced Chronic Kidney Disease: Walking the Fine Line Between Benefit and Harm

Chronic kidney disease affects more than 3 million Canadians and is highly associated with cardiovascular diseases that require anticoagulation, such as atrial fibrillation and venous thromboembolism. Patients with chronic kidney disease are at a problematic crossroads; they are at high risk of thrombotic conditions requiring anticoagulation and bleeding complications due to anticoagulation. The limited high-quality clinical evidence to guide decision-making in this area further compounds the dilemma. In this review, we discuss the physiology and epidemiology of bleeding and thrombosis in patients with kidney disease. We specifically focus on patients with advanced kidney disease (estimated glomerular filtration rate ≤ 30 mL/min) or who are receiving dialysis and focus on the nephrologist perspective regarding these issues. We summarize the existing evidence for anticoagulation use in the prevention of stroke with atrial fibrillation and provide practical clinical recommendations for considering anticoagulation use in this population. Last, we examine specific scenarios such as the use of a glomerular filtration rate estimating equation and dosing, the use of existing prediction tools for stroke and hemorrhage risk, current patterns of anticoagulation use (including during the dialysis procedure), and vascular calcification with vitamin K antagonist use in patients with chronic kidney disease.