Anticoagulation-related nephropathy

Warfarin-related nephropathy: unveiling the hidden dangers of anticoagulation

Warfarin-related nephropathy (WRN) is defined as acute kidney injury subsequent to excessive anticoagulation with warfarin. Patients with mechanical prosthetic valves require long-term anticoagulant therapy. Nonetheless, warfarin remains the sole available option for anticoagulant therapy. Consequently, patients with mechanical prosthetic valves constitute a special group among the entire anticoagulant population. The present study recorded two cases of patients who had undergone mechanical prosthetic valve surgery and were receiving warfarin therapy. They presented to the hospital with gross hematuria and progressive creatinine levels. Notably, their international normalized ratio (INR) did not exceed three. Subsequent renal biopsies confirmed WRN with IgA nephropathy. The two patients continued to receive warfarin as anticoagulation therapy and were prescribed oral corticosteroids and cyclophosphamide, which resulted in improved renal function during the follow-up. Based on a review of all relevant literature and the present study, we proposed a new challenge: must elevated INR levels be one of the criteria for clinical diagnosis of WRN? Perhaps some inspiration can be drawn from the present article.

Dabigatran-related Nephropathy Complicated by Tubulointerstitial Nephritis in a Patient with a Normal Renal Function and Undiagnosed IgA Nephropathy

A 69-year-old woman was referred to our hospital because of an acute kidney injury with macroscopic hematuria. She had been taking dabigatran for atrial flutter for six years. Based on the typical histological findings of her kidney biopsy and her history of dabigatran use with prolonged activated partial thromboplastin time, she was diagnosed with dabigatran-related nephropathy complicated by tubulointerstitial nephritis with IgA nephropathy. After prednisolone therapy, the renal function improved. Direct-acting oral anticoagulants, including dabigatran, may cause anticoagulant-related nephropathy similar to warfarin, even in patients with a normal renal function. Tubulointerstitial nephritis may coexist with dabigatran-related nephropathy, and prednisolone therapy should be considered in such cases. IgA nephropathy has been reported as a background disease, and caution should be exercised when encountering it.

Incidence and Predictors of Worsening Renal Function in Edoxaban-Treated Atrial Fibrillation Patients Within ETNA-AF-Europe Registry

Background

Managing patients with atrial fibrillation (AF) and worsening renal function (WRF) remains a clinical challenge due to the need of dose adjustment of non-vitamin K antagonist oral anticoagulants.

Objectives

To determine the incidence of WRF in patients with AF treated with edoxaban, the association of WRF with clinical outcomes, and predictors of WRF and clinical outcomes in these patients.

Methods

This is a subanalysis of the Edoxaban Treatment in routiNe clinical prActice for patients with non-valvular Atrial Fibrillation in Europe study (NCT02944019), an observational study of edoxaban-treated patients with AF. WRF was defined as a ≥25% reduction in creatinine clearance between baseline and 2 years.

Results

Of the 9,054 patients included (69% of the total 13,133 enrolled), most did not experience WRF (90.3%) during the first 2 years of follow-up. WRF occurred in 9.7% of patients. Patients with WRF had significantly higher rates of all-cause death (3.88%/y vs 1.88%/y; P < 0.0001), cardiovascular death (2.09%/y vs 0.92%/y; P < 0.0001), and major bleeding (1.51%/y vs 0.98%/y; P = 0.0463) compared with those without WRF. Rates of intracranial hemorrhage (0.18%/y vs 0.18%/y) and of any stroke/systemic embolic events were low (0.90%/y vs 0.69%/y; P = 0.3161) in both subgroups. The strongest predictors of WRF were a high CHA2DS2-VASc score, high baseline creatinine clearance, low body weight, and older age. Most predictors of WRF were also predictors of clinical outcomes.

Conclusions

WRF occurred in approximately 10% of edoxaban-treated AF patients. Rates of death and major bleeding were significantly higher in patients with WRF than without. Stroke events were low in both subgroups.

Long-Term Renal Involvement in Association with Fontan Circulation

Multiorgan dysfunction is a concern of Fontan patients. To clarify the pathophysiology of Fontan nephropathy, we characterize renal disease in the long-term observational study. Medical records of 128 consecutive Fontan patients [median age: 22 (range 15-37) years old] treated between 2009 and 2018 were reviewed to investigate the incidence of nephropathy and its association with other clinical variables. Thirty-seven patients (29%) showed proteinuria (n = 34) or < 90 mL/min/1.73 m2 of estimated glomerular filtration rate (eGFR) (n = 7), including 4 overlapping cases. Ninety-six patients (75%) had liver dysfunction (Forns index > 4.21). Patients with proteinuria received the Fontan procedure at an older age [78 (26-194) vs. 56 (8-292) months old, p = 0.02] and had a higher cardiac index [3.11 (1.49-6.35) vs. 2.71 (1.40-4.95) L/min/m2, p = 0.02], central venous pressure [12 (7-19) vs. 9 (5-19) mmHg, p < 0.001], and proportion with > 4.21 of Forns index (88% vs. 70%, p = 0.04) than those without proteinuria. The mean renal perfusion pressure was lower in patients with a reduced eGFR than those without it [55 (44-65) vs. 65 (45-102) mmHg, p = 0.03], but no other variables differed significantly. A multivariable analysis revealed that proteinuria was associated with an increased cardiac index (unit odds ratio 2.02, 95% confidence interval 1.12-3.65, p = 0.02). Seven patients with severe proteinuria had a lower oxygen saturation than those with no or mild proteinuria (p = 0.01, 0.03). Proteinuria or a decreased eGFR differentially occurred in approximately 30% of Fontan patients. Suboptimal Fontan circulation may contribute to the development of proteinuria and reduced eGFR.

Comparative safety review of antithrombotic treatment options for patients with atrial fibrillation undergoing percutaneous coronary intervention

INTRODUCTION

Balancing antithrombotic therapy for atrial fibrillation (AF) patients undergoing percutaneous coronary intervention (PCI) remains a clinical challenge due to coexisting thrombogenic risks. This review emphasizes the delicate balance required to prevent ischemic events while minimizing bleeding complications, particularly in the context of risk assessment.

AREAS COVERED

This review spans from 2010 to October 2023, exploring the complexities of antithrombotic management for AF patients undergoing PCI. It stresses the need for personalized treatment decisions to optimize antithrombotic therapies effectively.

EXPERT OPINION

The evolving evidence supports double antithrombotic therapy (DAT) over triple antithrombotic therapy (TAT) for these patients, showcasing a more favorable safety profile without compromising efficacy. Non-vitamin K antagonist oral anticoagulant (NOAC)-based DAT strategies exhibit superiority in reducing major bleeding events while effectively preventing ischemic events. Recommendations from the 2023 European Society of Cardiology (ESC) Guidelines advocate for NOAC-based DAT post-PCI, endorsing safer antithrombotic profiles.Challenges persist for specific patient categories requiring both oral anticoagulants and antiplatelets, necessitating personalized approaches. Future advances in intravascular imaging and novel coronary stent technologies offer promising avenues to optimize outcomes and influence antithrombotic strategies in AF-PCI patients.

Rivaroxaban vs Vitamin K Antagonist in Patients With Atrial Fibrillation and Advanced Chronic Kidney Disease

Background

Treatment with vitamin K antagonists (VKAs) has been linked to worsening of kidney function in patients with atrial fibrillation (AF).

Objectives

XARENO (Factor XA-inhibition in RENal patients with non-valvular atrial fibrillation Observational registry; NCT02663076) is a prospective observational study comparing adverse kidney outcomes in patients with AF and advanced chronic kidney disease receiving rivaroxaban or VKA.

Methods

Patients with AF and an estimated glomerular filtration rate (eGFR) of 15 to 49 mL/min/1.73 m2 were included. Blinded adjudicated outcome analysis evaluated adverse kidney outcomes (a composite of eGFR decline to <15 mL/min/1.73 m2, need for chronic kidney replacement therapy, or development of acute kidney injury). A composite net clinical benefit outcome (stroke or systemic embolism, major bleeding, myocardial infarction, acute coronary syndrome, or cardiovascular death) was also analyzed. HRs with 95% CIs were calculated using propensity score overlap weighting Cox regression.

Results

There were 1,455 patients (764 rivaroxaban; 691 VKA; mean age 78 years; 44% females). The mean eGFR was 37.1 ± 9.0 in those receiving rivaroxaban and 36.4 ± 10.1 mL/min/1.73 m2 in those receiving VKA. After a median follow-up of 2.1 years, rivaroxaban was associated with less adverse kidney outcomes (HR: 0.62; 95% CI: 0.43-0.88) and all-cause death (HR: 0.76, 95% CI: 0.59-0.98). No significant differences were observed in net clinical benefit.

Conclusions

In patients with AF and advanced chronic kidney disease, those receiving rivaroxaban had less adverse kidney events and lower all-cause mortality compared to those receiving VKA, supporting the use of rivaroxaban in this high-risk group of patients.

The Crosstalk between Nephropathy and Coagulation Disorder: Pathogenesis, Treatment, and Dilemmas

ABSTRACT

The interaction between the kidney and the coagulation system greatly affects each other because of the abundant vessel distribution and blood perfusion in the kidney. Clinically, the risks of complicated thrombosis and bleeding have become important concerns in the treatment of nephropathies, especially nephrotic syndrome, CKD, ESKD, and patients with nephropathy undergoing RRTs. Adverse effects of anticoagulant or procoagulant therapies in patients with nephropathy, especially anticoagulation-related nephropathy, heparin-induced thrombocytopenia, and bleeding, seriously worsen the prognosis of patients, which have become challenges for clinicians. Over the decades, the interaction between the kidney and the coagulation system has been widely studied. However, the effects of the kidney on the coagulation system have not been systematically investigated. Although some coagulation-related proteins and signaling pathways have been shown to improve coagulation abnormalities while avoiding additional kidney damage in certain kidney diseases, their potential as anticoagulation targets in nephropathy requires further investigation. Here, we review the progression of research on the crosstalk between the coagulation system and kidney diseases and systematically analyze the significance and shortcomings of previous studies to provide new sight into future research. In addition, we highlight the status of clinical treatment for coagulation disorder and nephropathy caused by each other, indicating guidance for the formulation of therapeutic strategies or drug development.

Medium-term and long-term renal function changes with direct oral anticoagulants in elderly patients with atrial fibrillation

Objective: Atrial Fibrillation (AF) and chronic kidney disease frequently coexist in the elderly. Warfarin-like drugs (WLDs) may be associated with a relatively greater decrease of estimated glomerular filtration rate (eGFR) as compared to direct oral anticoagulants (DOACs), but there is no evidence on the medium- and long-term changes. To further elucidate this issue in elderly patients with AF, we investigated the renal function deterioration in the two groups of the study (DOACs or WLDs). Patients and Methods: A total of 420 AF patients were enrolled (mean age: 77.0 ± 6.0 years; 136 on WLDs and 284 on DOACs). These patients underwent three eGFR measurements during the follow-up period. The between-arms difference of eGFR decline over time was investigated by Linear Mixed Models and group-based trajectory model analyses. Results: In the whole study cohort, after a median follow-up of 4.9 years (interquartile range: 2.7-7.0 years), eGFR decreased from 67.4 ± 18.2 to 47.1 ± 14.3 mL/min/1.73 m² (p < 0.001). Remarkably, patients on DOACs experienced a significantly smaller eGFR decline than WLDs patients (-21.3% vs. -45.1%, p < 0.001) and this was true both in the medium-term (-6.6 vs. -19.9 mL/min/1.73 m²) and in the long-term (-13.5 versus -34.2 mL/min/1.73 m²) period. After stratification into five subgroups according to trajectories of renal function decline over time, logistic regression showed that DOACs patients had from 3.03 to 4.24-fold greater likelihood to belong to the trajectory with less marked eGFR decline over time than WLDs patients. Conclusion: Elderly patients with AF on treatment with DOACs had a relatively smaller decline of eGFR over time compared to those on treatment with WLDs. This is consistent with what was partly reported in the literature.

The impact of anticoagulation therapy on kidney function in patients with atrial fibrillation and chronic kidney disease

INTRODUCTION

Atrial fibrillation (AF) and chronic kidney disease (CKD) are closely related. These diseases share common risk factors and are associated with increased risk of thromboembolic events. Choosing the appropriate oral anticoagulant therapy (OAC) in patients with AF and CKD is challenging. Deterioration of renal function is common in patients with AF treated with OACs, although not all OACs affect the kidneys equally.

AREAS COVERED

In this review, we aim to summarize the current knowledge of the prevention of thromboembolic events in patients with AF and CKD, focusing on the impact of specific OAC agents on renal function.

EXPERT OPINION

Consideration of OAC use is mandatory in patients with AF and CKD who are at increased risk of stroke or systemic embolism. Available evidence suggests that the use of non-vitamin K antagonist oral anticoagulants (NOACs) is associated with slower deterioration of renal function in comparison to Vitamin K antagonists (VKAs). Hence, a NOAC should be used in preference to VKAs in all NOAC-eligible patients with AF and CKD. Regarding patients with end-stage renal dysfunction and those on dialysis or renal replacement therapy, the use of NOAC should be considered in line with locally relevant formal recommendations.

Anticoagulant-related nephropathy induced by direct-acting oral anticoagulants: Clinical characteristics, treatments and outcomes

INTRODUCTION

There is a scarcity of data on anticoagulation-related nephropathy (ARN) caused by direct-acting oral anticoagulants (DOACs) in recent years.

MATERIALS AND METHODS

We collected literatures on DOACs-induced ARN to October 1, 2022, without language restrictions for retrospective analysis.

RESULTS

Twenty events were included with a median onset time of 28 days among which fourteen were caused by dabigatran. Patients accompanied by chronic kidney disease (85 %) seemed more easily to have an ARN. Clinical symptoms associated with ARN were mostly presented as hematuria and acute decline of renal function (100 %), then abnormal coagulation function (75 %) but only one with an INR over 3. Renal biopsies were performed in 14 patients, with thirteen showing occlusive intratubular red blood cell casts and ten showing acute tubular injury of varying intensity or even tubular necrosis. Extensive changes in interstitial compartment like hemorrhage, fibrosis or inflammation were also presented in eight biopsies. IgA nephropathy as a latent or undiagnosed disease was demonstrated in eight biopsies. Treatments of ARN were mainly supportive with all patients discontinuing DOACs and 35 % initiating dialysis for acute deterioration of renal function. Steroids were used in 9 patients with a severe ARN verified by biopsy. 60 % of patients did not recover baseline renal function and some even deteriorated.

CONCLUSIONS

In conclusion, DOACs-induced ARN is a rare but serious adverse reaction. A prompt diagnosis of ARN and supportive treatments are necessary for patients receiving DOACs concurrent with an acute renal injury.

Effects of direct oral anticoagulants vs. vitamin K antagonists on acute kidney injury in patients with atrial fibrillation: A systematic review

Background

Patients with atrial fibrillation (AF) are routinely prescribed oral anticoagulants to prevent thromboembolism. Concerns regarding the efficacy and safety of oral anticoagulants, such as vitamin K antagonists (VKA) and direct oral anticoagulants (DOACs), arise for patients with non-valvular atrial fibrillation (NVAF) because of their widespread use in clinical practice. Even though there have been an abundance of studies on this topic, it is still not clear if DOAC users with NVAF have a lower risk of acute kidney injury (AKI) than warfarin users.

Methods and results

We conducted electronic searches in PubMed, Embase, and the Cochrane Library to identify relevant studies for this systematic review. We included randomized clinical trials and observational studies that reported on the incidence rate, hazard ratio (HR), and 95% confidence interval (95% CI) of AKI in patients using oral anticoagulants. This systemic review included six observational studies and four randomized clinical trials (RCT). The overall results showed that DOACs were associated with a lower AKI risk than warfarin. However, for NVAF patients with severe renal dysfunction, DOACs may not have a reduced risk of AKI compared to warfarin.

Conclusion

The overall results suggest that, except for edoxaban, patients using DOACs may experience a reduced risk of AKI. However, it is uncertain whether this is also the case for patients with severe renal dysfunction. Further research is needed to confirm the effect of DOACs on this population.

Warfarin Related Kidney Damage: A Confusing Case of Thrombophlebitis Masquerading as Infection

Anticoagulant-related nephropathy (ARN) is a rare, newly recognized cause of acute kidney injury and significant but underdiagnosed complication of anticoagulation therapy. ARN occurs in patients taking oral anticoagulant therapy most often warfarin or a novel oral anticoagulant (NOAC). It is a potentially devastating disorder with serious renal consequences and increased all-cause mortality. Anticoagulant-related nephropathy presents as an acute kidney injury (AKI) in the setting of a supratherapeutic INR with profuse glomerular hemorrhage seen as renal tubules filled with red cells and red cell casts on renal biopsy. Being that millions of Americans are on warfarin, a thorough understanding and awareness of the clinical presentation, diagnosis, and therapeutic interventions are crucial to protecting the renal function, lowering all-cause mortality and optimizing treatment. Our goal is to provide education on a newly recognized form of AKI and significant but underdiagnosed complication of anticoagulation therapy.

Organ Crosstalk in Acute Kidney Injury: Evidence and Mechanisms

Acute kidney injury (AKI) is becoming a public health problem worldwide. AKI is usually considered a complication of lung, heart, liver, gut, and brain disease, but recent findings have supported that injured kidney can also cause dysfunction of other organs, suggesting organ crosstalk existence in AKI. However, the organ crosstalk in AKI and the underlying mechanisms have not been broadly reviewed or fully investigated. In this review, we summarize recent clinical and laboratory findings of organ crosstalk in AKI and highlight the related molecular mechanisms. Moreover, their crosstalk involves inflammatory and immune responses, hemodynamic change, fluid homeostasis, hormone secretion, nerve reflex regulation, uremic toxin, and oxidative stress. Our review provides important clues for the intervention for AKI and investigates important therapeutic potential from a new perspective.

Acute Kidney Injury in Patients with Non-Valvular Atrial Fibrillation Treated with Rivaroxaban or Warfarin: A Population-Based Study from the United Kingdom

PURPOSE

To compare the risk of acute kidney injury (AKI) among users of rivaroxaban vs warfarin.

PATIENTS AND METHODS

We identified two cohorts of patients with non-valvular atrial fibrillation (NVAF) who initiated rivaroxaban (15/20 mg/day, N = 6436) or warfarin (N = 7129) excluding those without estimated glomerular filtration rate values recorded in the year before oral anticoagulant (OAC) initiation and those with a history of end-stage renal disease or AKI. We used two methods to define AKI during follow-up (mean 2.5 years): coded entries (method A) and the Aberdeen AKI phenotyping algorithm (method B) using recorded renal function laboratory values during the study period to identify a sudden renal deterioration event. Cox regression was used to calculate hazard ratios (HRs) for AKI with rivaroxaban vs warfarin use, adjusted for confounders.

RESULTS

The number of identified incident AKI cases was 249 (method A) and 723 (method B). Of the latter, 104 (14.4%) were also identified by method A. After adjusting for age, sex, baseline renal function and comorbidity, HRs (95% CIs) for AKI were 1.19 (0.92-1.54; p=0.18) using method A and 0.80 (0.68-0.93; p<0.01) using method B. Estimates stratified by baseline level of chronic kidney disease were largely consistent with the main estimates.

CONCLUSION

Our results support a beneficial effect of rivaroxaban over warfarin in terms of AKI occurrence in patients with NVAF. More research into how best to define AKI using primary care records would be valuable for future studies.

Managing thrombotic risk in patients with diabetes

It is well known that diabetes is a prominent risk factor for cardiovascular (CV) events. The level of CV risk depends on the type and duration of diabetes, age and additional co-morbidities. Diabetes is an independent risk factor for atrial fibrillation (AF) and is frequently observed in patients with AF, which further increases their risk of stroke associated with this cardiac arrhythmia. Nearly one third of patients with diabetes globally have CV disease (CVD). Additionally, co-morbid AF and coronary artery disease are more frequently observed in patients with diabetes than the general population, further increasing the already high CV risk of these patients. To protect against thromboembolic events in patients with diabetes and AF or established CVD, guidelines recommend optimal CV risk factor control, including oral anticoagulation treatment. However, patients with diabetes exist in a prothrombotic and inflammatory state. Greater clinical benefit may therefore be seen with the use of stronger antithrombotic agents or innovative drug combinations in high-risk patients with diabetes, such as those who have concomitant AF or established CVD. In this review, we discuss CV risk management strategies in patients with diabetes and concomitant vascular disease, stroke prevention regimens in patients with diabetes and AF and how worsening renal function in these patients may complicate these approaches. Accumulating evidence from clinical trials and real-world evidence show a benefit to the administration of non-vitamin K antagonist oral anticoagulants for stroke prevention in patients with diabetes and AF.

Challenging clinical scenarios for therapeutic anticoagulation: A practical approach

Therapeutic anticoagulation remains a fundamental backbone in the treatment and prevention of venous thromboembolism. However, while modern therapies are increasingly safe, anticoagulation is not without risks, particularly in those at high risk for or with recent bleeding. When weighing concurrent risks and benefits in each challenging clinical scenario, an individualized assessment of the risk and acuity of bleeding should be balanced by the indication for anticoagulation. Addressing modifiable risk factors and routine re-evaluation of any changes in this balance is critical. This review outlines available data and current guidelines for the management of anticoagulation in high-risk populations, including those with thrombocytopenia, elderly and high-fall risk, inherited bleeding disorders, and in acute coronary syndrome. We also examine management after clinically significant bleeding episodes, including intracranial hemorrhage, gastrointestinal bleeding, hemoptysis, retroperitoneal bleeding, hematuria, and abnormal uterine bleeding. The aim is to provide a comprehensive review of available literature to guide clinicians in providing optimal, safe, and individualized care for patients in these challenging scenarios.

Worsening of kidney function in patients with atrial fibrillation and chronic kidney disease: evidence from the real-world CALLIPER study

OBJECTIVE

Evidence is needed on the impact of anticoagulation therapy on kidney function in patients with atrial fibrillation (AF). The objective of this analysis, which is part of the CALLIPER study, was to investigate the risk of worsening kidney function with rivaroxaban 15 mg once daily compared with warfarin in patients with AF and moderate-to-severe chronic kidney disease (CKD) in routine clinical practice in the United States.

METHODS

CALLIPER was an observational, retrospective, new-user cohort study. Adult patients with AF in the US IBM Watson MarketScan databases who newly initiated anticoagulation with rivaroxaban 15 mg once daily or warfarin between January 2013 and December 2017 were included. Comparative analysis was performed using Cox proportional hazards regression after adjustment for potential confounding by the stabilized inverse probability of treatment weighting approach and propensity score matching. One of the main study outcomes was worsening kidney function (composite of progression to CKD stage 5, kidney failure, or need for dialysis), besides traditional AF-related outcomes.

RESULTS

The cohort included 7368 patients: 5903 (80.1%) initiating warfarin and 1465 (19.9%) initiating rivaroxaban 15 mg once daily. Rivaroxaban 15 mg was associated with a significant 47% reduction in the risk of worsening kidney function versus warfarin (hazard ratio 0.53; 95% confidence interval 0.35-0.78). Similar results were observed in the subgroup of patients with type 2 diabetes.

CONCLUSIONS

Rivaroxaban 15 mg may be associated with a lower risk of worsening kidney function as compared with warfarin in the atrial fibrillation population with moderate-to-severe CKD.

TRIAL REGISTRATION NUMBER

NCT03359876.

Warfarin-Related Nephropathy Manifested as Diffuse Mesangial Proliferative Glomerulonephritis

Warfarin is associated with anticoagulant-related nephropathy (ARN), one of the potential side effects. This is evidenced by a progressively increasing number of detected cases of deterioration in the kidney function even in patients with normal baseline function (GFR {glomerular filtration rate}) in addition to the chronic kidney disease (CKD) patients who are already vulnerable to ARN. There has been a clinical correlation in a rapid decline of kidney function and international normalized ratio (INR) levels of greater than three. ARN is a significant but underdiagnosed complication of anticoagulation that is associated with increased renal morbidity and all-cause mortality. We want to emphasize the importance of monitoring kidney function regularly and adjusting the appropriate doses of warfarin. We present a case of a 57-year-old female who was on warfarin for the mechanical aortic valve, presented with acute kidney injury and supratherapeutic INR. Her renal biopsy showed diffuse mesangial proliferative glomerulonephritis.

Anticoagulant-Related Nephropathy: A Common, Under-Diagnosed Clinical Entity

Anticoagulant-related nephropathy (ARN) is a clinical entity consisting of the constellation of acute kidney injury (AKI) and hematuria in patients receiving anticoagulation therapy. It was formerly known as warfarin-induced nephropathy. The underlying pathogenesis remains yet to be fully clarified. Diagnosis is established by kidney biopsy, which has possibly led to underreporting of the disease. Patients usually present with a supratherapeutic INR. Herein, we present a case of acute kidney injury secondary to anticoagulant-related nephropathy.

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.

Medical therapies for prevention of cardiovascular and renal events in patients with atrial fibrillation and diabetes mellitus

Atrial fibrillation (AF), type 2 diabetes mellitus (DM), and chronic kidney disease (CKD) are three global epidemics with significant effects on morbidity and mortality. Diabetes is a risk factor for AF, and a risk factor for thromboembolism, comorbidity, and mortality when AF is present. The pathophysiology of diabetes-related AF and interrelationships with cardiovascular events and renal events is not fully understood but is in part related to structural, electrical, electromechanical, and autonomic remodelling. The current practice guidelines offer limited recommendations on the management of patients with AF (or risk of AF) and diabetes with its own heterogeneity for the prevention of cardiovascular and renal events. This document discusses possible clinical approaches for these patients. In the last decade, there have been major improvements for the prevention of stroke in AF patients with direct oral anticoagulants, which are preferable to vitamin K antagonists for stroke prevention in DM. Because of the increased risk rate for several cardiovascular adverse events in diabetic patients, a similar relative risk reduction generally translates into greater absolute risk reduction in the diabetic population. Recent trials with non-insulin diabetes drugs using glucagon-like peptide-1 agonists and sodium-glucose cotransporter-2 inhibitors showed a significant reduction for the risk of major adverse cardiovascular events in patients with type 2 DM. Sodium-glucose cotransporter-2 inhibitors also showed a large reduction in hospitalization for heart failure and renal events, which need to be more completely evaluated in patients with AF. Mechanisms, risks, and optimal management of AF patients with DM who have or are under risk of developing heart failure or CKD are also discussed in this document. The benefits of medical therapies for these patients still need to be put into perspective, and gaps in evidence on some of these issues are likely to be addressed in future years.

The change of renal functions after nonvitamin K oral anticoagulants in patients with atrial fibrillation

Oral anticoagulants decreased stroke and mortality in atrial fibrillation patients. There have been cumulative data suggesting that some oral anticoagulants may exert favorable renal outcomes.The aim of this study is to evaluate the renal outcomes in patients with atrial fibrillation who took oral anticoagulant.

METHODS

A Retrospective cohort study using hospital electronic database. Serum creatinine and GFR were collected at baseline and at 1 and 2 years.

RESULTS

Authors identified 734 patients with non-valvular AF who took oral anticoagulants. At the end of 2-year, the cumulative risk of significant GFR decline (eGFR drop > 30%) was 10.94% in warfarin group and 9.69% in NOACs group.The incidence rate of significant eGFR decline were comparable between NOACs and warfarin group which were 4.82 and 5.34 per 100-patient year respectively(HR 1.01 CI 0.62-1.66 , p- value 0.964).However, the adjusted mean eGFR change per year was significantly lower in NOAC group, especially rivaroxaban (coefficient 7.83 ,CI 4.44 11.22 , p-value < 0.001) and dabigatran (coefficient 6.22 ,CI 2.67-9.77 , p-value = 0.001) at 2 years.

CONCLUSIONS

Significant GFR decline was not uncommon in non-valvular AF patients who received anticoagulant. Among these, the proportion of patients who had significant eGFR decline(>30%) were comparable between NOACs and warfarin at 2 years. However, there is a significantly less mean eGFR decline per year in patients who receive NOACs, notably with dabigatran and rivaroxaban, than those who receive warfarin.The findings of this study should be interpreted in the context of patients included in this study.

Acute kidney injury in patients with acute coronary syndrome after percutaneous coronary intervention: pathophysiologies, risk factors and preventive measures

Background: Percutaneous coronary intervention (PCI) has been an effective treatment for acute coronary syndrome (ACS) patients. Acute kidney injury (AKI) is one of the common complications after PCI, which seriously affects the living quality and survival time of patients. The approach followed for the patient with AKI after PCI depends on the clinical context and may vary by resource availability. Summary: This review focuses on the pathophysiologies, influencing factors, and preventive measures of AKI in patients with ACS after PCI. The knowledge may better serve the patients and improve their outcomes. Key Messages: Many studies have been carried out for the definition and standard of AKI in the past few years. Etiologies of AKI after PCI included renal damage of contrast medium and atherosclerotic embolism, cardiac insufficiency and surgical factors on renal function. Basic conditions, treatment modalities, and perioperative changes are major risk factors of AKI. Studies have reported that the prevention of contrast-induced nephropathy, modulating the volume overload, some pharmaceuticals and blood purification treatment are helpful to prevent the occurrence of AKI.

Dabigatran-Induced Nephropathy and Gastrointestinal Bleeding and Its Successful Treatment with Idarucizumab: A Case Report

Recently, the atrial fibrillation treatment guidelines have been updated to now recommend Non-vitamin K antagonist oral anticoagulants (NOACs) as the preferred alternative to warfarin for systemic embolism and stroke prevention in patients with non-valvular atrial fibrillation. NOACs have major pharmacologic advantages over warfarin, although the most common complications are gastrointestinal bleeding and NOAC-induced nephropathy within 6 weeks after starting therapy, as several recent case-reports stated. We are reporting for the first time a chronic delayed adverse reaction (regularly reported to Authorities) observed in an 82-year-old woman 27 months after starting dabigatran (110 mg twice a day), characterized by concomitant gastrointestinal bleeding and nephropathy. Idarucizumab administration immediately improved both bleeding and renal parameters. Moreover, we are going to highlight the importance of the compliance, the adherence to the therapeutic plan and the supervision of the Hospital Pharmacy on drug prescriptions. In fact in our case, dabigatran was firstly prescribed by the neurologist and delivered by the hospital pharmacy, but the patient continued the treatment for 27 months, prescribed by general practitioner without any laboratory control. This lack of supervision certainly contributed to the onset of the adverse reaction reported.

Warfarin-related nephropathy: A case report of a delayed renal function improvement

We experienced a case in which improving the renal damage caused by warfarin-related nephropathy took a long time. It is important to follow up for a long time after the initiation of dialysis due to warfarin-related nephropathy.

Management of Anticoagulant-Related Nephropathy: A Single Center Experience

BACKGROUND

Anticoagulant-related nephropathy (ARN) is a form of acute kidney injury that mainly occurs in patients with previously unrecognized glomerular disease in addition to excessive anticoagulation. Since a renal biopsy is not performed in most cases, the diagnosis is often presumptive.

METHODS

Here, we present the characteristics of a national Slovenian patient cohort with histologically verified ARN, from the first case in 2014 to December 2020, and a review of the current literature (Pubmed database).

RESULTS

In Slovenia, ARN has been detected in 13 patients, seven of whom were treated with coumarins, and others with direct oral anticoagulants. In seven patients, ARN appeared after excessive anticoagulation. As many as 11 patients had underlying IgA nephropathy. Similar to the global data presented here, the pathohistological impairment associated with pre-existing glomerulopathy was mild and disproportionate to the degree of functional renal impairment. The majority of our patients with ARN experienced severe deterioration of renal function associated with histological signs of accompanying acute tubular injury, interstitial edema, and occlusive red blood cell casts. These patients were treated with corticosteroids, which (in addition to supportive treatment and discontinuation of the anticoagulant drug) led to a further improvement in renal function.

CONCLUSIONS

Anticoagulant therapy combined with a pre-existing glomerular injury may lead to ARN. In addition to discontinuation of the anticoagulant and supportive care, corticosteroids, which are currently listed in only a few cases in the world literature, may have a positive influence on the course of treatment. However, the benefits of steroid treatment must be weighed against the risk of complications, especially life-threatening infections.

Use of Non-vitamin K Antagonist Oral Anticoagulants for Stroke Prevention across the Stroke Spectrum: Progress and Prospects

Multiple randomized controlled trials and many real-world evidence studies have consistently shown that non-vitamin K antagonist oral anticoagulants (NOACs) are preferable to vitamin K antagonists for thromboembolic stroke prevention in the majority of patients with atrial fibrillation (AF). However, their role in the management of patients with AF and comorbidities, as well as in other patient populations with a high risk of stroke, such as patients with prior embolic stroke of undetermined source (ESUS) and those with atherosclerosis, is less clear. There is now increasing evidence suggesting that NOACs have a beneficial effect in the prevention of stroke in patients with AF and comorbidities, such as renal impairment and diabetes. In addition, while studies investigating the efficacy and safety of NOACs for the prevention of secondary stroke in patients with a history of ESUS demonstrated neutral results, subanalyses suggested potential benefits in certain subgroups of patients with ESUS. One NOAC, rivaroxaban, has also recently been found to be effective in reducing the risk of stroke in patients with chronic cardiovascular disease including coronary artery disease and peripheral artery disease, further broadening the patient groups that may benefit from NOACs. In this article, we will review recent evidence for the use of NOACs across the stroke spectrum in detail, and discuss the progress and future prospects in the different stroke areas.

Concomitant diabetes with atrial fibrillation and anticoagulation management considerations

Atrial fibrillation is a highly prevalent cardiac arrhythmia. It is associated with numerous co mobilities. Approximately 30% of diabetic patients have atrial fibrillation and 15% of atrial fibrillation regulation patients have diabetes mellitus. Diabetes increases the likelihood of the development of atrial fibrillation and contributes to the high risk of thromboembolism seen in patients with both diabetes and atrial fibrillation. Chronic kidney disease is often a consequence of diabetes and presents an additional challenge to the management of patients with both atrial fibrillation and diabetes. All non-vitamin K oral anticoagulants are partially eliminated via the kidney and must be carefully prescribed according to strict dosing schedules to avoid anticoagulation overdose. However, NOACs have the advantage of being associated with less progressive impairment of renal function compared with vitamin K antagonist therapy in both diabetics and non-diabetics. Otherwise, diabetic patients benefit from NOAC therapy as opposed to vitamin K antagonists to a similar extent as patients without diabetes. This review deals with anticoagulation treatment in patients with fibrillation and diabetes mellitus, often complicated by progressive renal impairment.

Acute kidney injury pathology and pathophysiology: a retrospective review

Acute kidney injury (AKI) is the clinical term used for decline or loss of renal function. It is associated with chronic kidney disease (CKD) and high morbidity and mortality. However, not all causes of AKI lead to severe consequences and some are reversible. The underlying pathology can be a guide for treatment and assessment of prognosis. The Kidney Disease: Improving Global Outcomes guidelines recommend that the cause of AKI should be identified if possible. Renal biopsy can distinguish specific AKI entities and assist in patient management. This review aims to show the pathology of AKI, including glomerular and tubular diseases.

Acute Renal Failure in a Patient with Rivaroxaban-Induced Hypersensitivity Syndrome: A Case Report with a Review of the Literature and of Pharmacovigilance Registries

Direct oral anticoagulants (DOACs) are among the most commonly prescribed medications, and DOAC-associated kidney dysfunction may be a problem that is underrecognized by clinicians. We report on the case of an 82-year-old patient who, two weeks after the prescription of rivaroxaban for atrial fibrillation, was hospitalized for a drug-induced hypersensitivity syndrome whose main clinical manifestations were low-grade fever with a petechial rash in the legs and acute renal failure (ARF). Within one week after rivaroxaban withdrawal, the patient's clinical condition improved and the renal function normalized. In a review of the literature, we only found five case reports of rivaroxaban-related ARF: two patients had tubulo-interstitial nephritis (TIN), two had anticoagulant-related nephropathy (ARN), and the last one had IgA nephropathy. As some recent publications suggest that kidney injury due to anticoagulation drugs may be largely underdiagnosed, we also analyzed the data from the VigiAccess database, the World Health Organization pharmacovigilance program that collects drug-related adverse events from 134 national registries worldwide. Among all the rivaroxaban-associated adverse events reported in VigiAccess since 2006, 4,323 (3.5%) were renal side effects, of which 2,351 (54.3%) were due to unspecified ARF, 363 (8.4%) were due to renal hemorrhage (characteristically associated with ARN), and 24 (0.6%) were due to TIN. We also compared these results with those reported in VigiAccess for other DOACs and vitamin K antagonists. This analysis suggests that the frequency of renal adverse events associated with rivaroxaban and other DOACs may be appreciably higher than what one might currently consider based only on the small number of fully published cases.

Acute Kidney Injury due to Anticoagulant-Related Nephropathy : A Suggestion for Therapy

The relationship between kidneys and anticoagulation is complex, especially after introduction of the direct oral anticoagulants (DOAC). It is recently growing evidence of an anticoagulant-related nephropathy (ARN), a form of acute kidney injury caused by excessive anticoagulation. The pathogenesis of kidney damage in this setting is multifactorial, and nowadays, there is no established treatment. We describe a case of ARN, admitted to our Nephrology Unit with a strong suspicion of ANCA-associated vasculitis due to gross haematuria and haemoptysis; the patient was being given dabigatran. Renal biopsy excluded ANCA-associated vasculitis and diagnosed a red blood cell cast nephropathy superimposed to an underlying IgA nephropathy. Several mechanisms are possibly responsible for kidney injury in ARN: tubular obstruction, cytotoxicity of heme-containing molecules and free iron, and activation of proinflammatory/profibrotic cytokines. Therefore, the patient was given a multilevel strategy of treatment. A combination of reversal of coagulopathy (i.e., withdrawal of dabigatran and infusion of its specific antidote) along with administration of fluids, sodium bicarbonate, steroids, and mannitol resulted in conservative management of AKI and fast recovery of renal function. This observation could suggest a prospective study aiming to find the best therapy of ARN.

Association of different oral anticoagulants use with renal function worsening in patients with atrial fibrillation: A multicentre cohort study

AIMS

To investigate the decline of estimated glomerular filtration rate (eGFR) in patients with atrial fibrillation (AF) treated with vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs).

METHODS

Multicentre prospective cohort study including 1667 patients with nonvalvular AF. The eGFR was assessed by the CKD-EPI formula at baseline and during follow-up. The primary endpoint of the study was the median annual decline of eGFR according to VKA (n = 743) or NOAC (n = 924) use. As secondary endpoints, we analysed the transition to eGFR <50 mL/min/1.73 m² and the eGFR class worsening.

RESULTS

Median age was 73.7 ± 9.1 years and 43.3% were women. VKA-treated patients showed an eGFR decline of -2.11 (interquartile range [IQR] -5.68/-0.62), which was -0.27 (IQR -9.00/4.54, P < 0.001 vs VKAs), -1.21 (IQR -9.98/4.02, P = 0.004 vs VKAs) and -1.32 (IQR -8.70/3.99, P = 0.003 vs VKAs) in patients on dabigatran, rivaroxaban and apixaban, respectively. Transition to eGFR <50 mL/min/1.73 m² was lower in dabigatran- and apixaban-treated patients: odds ratio (OR) 0.492, 95% confidence interval (CI) 0.298-0.813, P = 0.006 and OR 0.449, 95% CI 0.276-0.728, P = 0.001, respectively. A lower rate of eGFR class worsening was found in all groups of NOACs compared to VKAs. No difference between full and reduced dose of NOAC was found. Subgroup analysis showed that the association between NOAC and eGFR changes was markedly reduced in diabetic patients.

CONCLUSION

Patients prescribed NOACs showed a lower decline of renal function compared to those prescribed VKAs. This effect was partially lost in patients with diabetes.

Narrative Review of Hypercoagulability in Small-Vessel Vasculitis

Pauci-immune necrotizing and crescentic glomerulonephritis (GN) is the most common etiology of rapidly progressive GN. Clinical presentation in those afflicted is usually related to rapid loss of kidney function. We report the case of a 70-year-old woman who came to medical attention for signs and symptoms related to lower-extremity deep vein thrombosis (DVT). At presentation, the patient had biochemical abnormalities consistent with active GN, which quickly progressed to rapid loss in kidney function requiring renal replacement therapy. Kidney biopsy revealed small-vessel vasculitis with glomerular crescents. Serologic studies were negative for antineutrophil cytoplasmic antibody antibodies and other causes of acute GN. Plasmapheresis, immunosuppressive, and anticoagulant therapies were prescribed. Absence of other apparent end-organ involvement with vasculitis pointed toward renal-limited small-vessel vasculitis, yet presence of unprovoked DVT argues for systemic vascular inflammation. This case illustrates that venous thrombosis can be the presenting manifestation in patients with vasculitis and silent, severe end-organ involvement. The epidemiology and pathophysiology of venous thromboembolism in small-vessel vasculitis are discussed in this report.

A practical approach to the pathology of renal intratubular casts

The identification and proper characterization of pathologic renal intratubular casts can be an arduous task, especially since they often admixed with non-pathologic casts, obfuscating debris and inflammation. The list of pathologic intratubular casts is long, and they can be easily missed or misdiagnosed without a thorough understanding of their pathophysiology and morphologic variety. Correct characterization of tubular casts is important since each cast type has a unique pathogenic mechanism, with specific treatment and prognostic implications. This review discusses the clinicopathologic characteristics of the six most common pathologic casts: light chain, hemoglobin, myoglobin, red cell, neutrophilic and bile casts. We also discuss hyaline and uromodulin casts, the commonly encountered "benign" cast types that share certain histologic features with pathologic casts. We limit the discussion to proteinaceous and cellular intratubular casts, with crystalline casts discussed in a separate review within the same journal issue. While not exhaustive, this review covers pathogenesis, clinical and prognostic significance, and a practical discussion of the histomorphologic spectrum of each cast type, along with commonly encountered pitfalls.

Impact of Continuous Flow Left Ventricular Assist Device Therapy on Chronic Kidney Disease: A Longitudinal Multicenter Study

BACKGROUND

Many patients undergoing durable left ventricular assist device (LVAD) implantation suffer from chronic kidney disease (CKD). Therefore, we investigated the effect of LVAD support on CKD.

METHODS

A retrospective multicenter cohort study, including all patients undergoing LVAD (HeartMate II (n = 330), HeartMate 3 (n = 22) and HeartWare (n = 48) implantation. In total, 227 (56.8%) patients were implanted as bridge-to-transplantation; 154 (38.5%) as destination therapy; and 19 (4.7%) as bridge-to-decision. Serum creatinine measurements were collected over a 2-year follow-up period. Patients were stratified based on CKD stage.

RESULTS

Overall, 400 patients (mean age 53 ± 14 years, 75% male) were included: 186 (46.5%) patients had CKD stage 1 or 2; 93 (23.3%) had CKD stage 3a; 82 (20.5%) had CKD stage 3b; and 39 (9.8%) had CKD stage 4 or 5 prior to LVAD implantation. During a median follow-up of 179 days (IQR 28-627), 32,629 creatinine measurements were available. Improvement of kidney function was noticed in every preoperative CKD-stage group. Following this improvement, estimated glomerular filtration rates regressed to baseline values for all CKD stages. Patients showing early renal function improvement were younger and in worse preoperative condition. Moreover, survival rates were higher in patients showing early improvement (69% vs 56%, log-rank P = 0 .013).

CONCLUSIONS

Renal function following LVAD implantation is characterized by improvement, steady state and subsequent deterioration. Patients who showed early renal function improvement were in worse preoperative condition, however, and had higher survival rates at 2 years of follow-up.

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 Nephrological Aspects of the Use of Rivaroxaban and Other Direct Peroral Anticoagulants in Non-Valvular Atrial Fibrillation]

Chronic kidney disease (CKD) is a powerful cardiovascular risk factor, its presence is accompanied by an increased risk of hospitalization for exacerbation of chronic heart failure (CHF), adverse outcomes in myocardial infarction, and cardiovascular mortality. Among the adverse events, an increased risk of atrial fibrillation (AF) should be noted. This article contains discussion of current approaches to the treatment of AF in patients with different stages of CKD, data on benefits of certain direct oral anticoagulants, as well as comparative characteristics of therapy with direct oral anticoagulants and warfarin. Pharmacokinetics and pharmacodynamics of direct oral anticoagulants, which determine the features of therapy in CKD, are also considered.

Changes in renal function and occurrence of contrast-induced nephropathy after percutaneous coronary interventions in patients with atrial fibrillation treated with non-vitamin K oral anticoagulants or warfarin

INTRODUCTION

Patients with atrial fibrillation (AF) receiving non-vitamin K oral anticoagulants (NOAC) have a slower decline in renal function than those taking warfarin. Moreover, a warfarin-related nephropathy has been described.

AIM

We assessed variation of estimated glomerular filtration rate (eGFR) and occurrence of contrast-induced nephropathy (CIN) after percutaneous coronary intervention (PCI) in patients with AF taking warfarin compared with NOAC.

MATERIAL AND METHODS

We retrospectively enrolled consecutive patients taking oral anticoagulation for AF undergoing PCI. The primary endpoint was variation in eGFR and serum creatinine levels within 48-72 h after PCI. The secondary endpoint was occurrence of CIN, defined as a ≥ 25% relative increase, or a ≥ 0.5 mg/dl absolute increase, in serum creatinine levels within 48-72 h.

RESULTS

We enrolled 420 patients (mean age: 75.0 ±5.5 years, 272 (64.7%) male), 124 (29.5%) treated with NOAC and 296 (70.5%) with warfarin. NOAC patients showed a reduced decline in renal function (eGFR change: -2.8 ±7.9 ml/min/1.73 m2 vs. -4.5 ±6.5 ml/min/1.73 m2, respectively, p = 0.02) and a smaller increase in serum creatinine levels (0.026 ±0.112 vs. 0.055 ±0.132, p = 0.032) after PCI compared with warfarin. In the multivariate linear regression model independent predictors of eGFR changes were diabetes, baseline eGFR ≤ 60 ml/min/1.73 m2 and warfarin use. Occurrence of CIN did not differ between NOAC and warfarin patients (13 (10.5%) vs. 46 (15.5%), p = 0.22).

CONCLUSIONS

Patients with AF taking NOAC have a reduced decline in renal function after PCI compared with warfarin. The NOAC may be a reasonable option for patients with a high risk of developing CIN.

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.

Clinical Pharmacology of Oral Anticoagulants in Patients with Kidney Disease

Oral anticoagulants are commonly used drugs in patients with CKD and patients with ESKD to treat atrial fibrillation to reduce stroke and systemic embolism. Some of these drugs are used to treat or prevent deep venous thrombosis and pulmonary embolism in patients with CKD who undergo knee and hip replacement surgeries. Warfarin is the only anticoagulant that is approved for use by the Food and Drug Administration in individuals with mechanical heart valves. Each oral anticoagulant affects the coagulation profile in the laboratory uniquely. Warfarin and apixaban are the only anticoagulants that are Food and Drug Administration approved for use in patients with CKD and patients with ESKD. However, other oral anticoagulants are commonly used off label in this patient population. Given the acquired risk of bleeding from uremia, these drugs are known to cause increased bleeding events, hospitalization, and overall morbidity. Each anticoagulant has unique pharmacologic properties of which nephrologists need to be aware to optimally manage patients. In addition, nephrologists are increasingly asked to aid in the management of adverse bleeding events related to oral anticoagulant use in patients with CKD and patients with ESKD. This article summarizes the clinical pharmacology of these drugs and identifies knowledge gaps in the literature related to their use.

Dabigatran causing severe acute kidney injury in a patient with liver cirrhosis

Anticoagulant-related nephropathy (ARN), a significant but frequently undiagnosed problem in patients receiving anticoagulation, is found to be associated with increased renal morbidity and all-cause mortality. While ARN is mainly associated with warfarin use, recent case reports suggest that it may also occur in patients taking direct oral anticoagulants (DOAC). We report a patient who had a history of alcoholic liver cirrhosis and paroxysmal atrial fibrillation, and received dabigatran 110 mg twice daily for 1 year. He presented with gross hematuria and severe acute kidney injury with an international normalized ratio of 4.09. Dabigatran was stopped and he was put on temporary hemodialysis support. His renal function gradually improved when the hematuria subsided. Renal biopsy later confirmed the presence of red blood cell casts inside the renal tubules with features of IgA nephropathy. Finally, his renal function returned back to baseline level. As DOAC has been increasingly used nowadays for the treatment of various thromboembolic diatheses, regular monitoring of renal function is warranted, especially in patients with underlying glomerular diseases and coagulopathy such as chronic liver diseases.

Anticoagulant-related nephropathy: systematic review and meta-analysis

Background

The aim of this study was to report the prevalence and mortality associated with anticoagulant-related nephropathy (ARN) through a systematic review of the literature.

Methods

Electronic searches were conducted in the Medline and EMBASE databases, and manual searches were performed in the reference lists of the identified studies. The studies were selected by two independent researchers, first by evaluating the titles and abstracts and then by reading the complete texts of the identified studies. Case series, cross-sectional studies, cohort studies and case–control studies reporting the prevalence and factors associated with ARN were selected. The methodological quality was assessed using the Newcastle–Ottawa scale. Meta-analyses of the prevalence of ARN and 5-year mortality using the random effects model were performed when possible. Heterogeneity was assessed using the I² statistic.

Results

Five studies were included. Prevalence of ARN ranged from 19% to 63% among the four included cohort studies. Meta-analysis of these resulted in high heterogeneity [I² 96%, summary effect 31%; 95% confidence interval (CI) 22–42%]. Subgroup meta-analysis yielded an ARN prevalence of 20% among studies that included patients with fewer comorbidities (I² 12%; 95% CI 19–22%). In a direct comparison, meta-analysis of the 5-year mortality rate between anticoagulated patients who had experienced ARN and anticoagulated patients without ARN, patients with ARN were 91% more likely to die (risk ratio = 1.91; 95% CI 1.22–3; I² 87%). Risk factors for ARN that were reported in the literature included initial excessive anticoagulation, chronic kidney disease, age, diabetes, hypertension, cardiovascular disease and heart failure.

Conclusions

ARN studies are scarce and heterogeneous, and present significant methodological limitations. The high prevalence of ARN reported herein suggests that this entity is underdiagnosed in clinical practice. Mortality in patients with ARN seems to be high compared with patients without this condition in observational studies.

Impact of anticoagulation and platelet antiaggregation on anaemia and haemorragic events in patients with chronic kidney disease stages 3 and 4

BACKGROUND AND OBJECTIVE

There is controversy concerning the risk/benefit of anticoagulation/antiaggregation in chronic kidney disease (CKD) patients. We analysed the impact of anticoagulation/antiaggregation on anaemia and haemorrhagic events in CKD patients.

PATIENTS AND METHODS

A total of 232 CKD patients stages 3 and 4 were followed during a mean follow-up time of 36.7 ± 11.6 months: 81 patients did not receive any anticoagulation or antiaggregation treatment, 91 received anticoagulation treatment and 60 patients received platelet antiaggregation. Haemorrhagic and cardiovascular events were recorded.

RESULTS

Haemoglobin and ferritine levels were significantly higher in patients who did not receive anticoagulation or antiaggregation (Hb 13.7 ± 1.6, 13.3 ± 1.8 and 12.7±1.9g/dl, p=0.004; ferritine 170 ± 145, 140 ± 138, 105 ± 99μg/l, p=0.023). During follow up, 36 haemorrhagic events were registered: 4in the control group, 23 in the anticoagulation group and 9in the antiaggregation group (log rank 12.5; p=0.002). In a Cox model adjusted by age, renal function and haemoglobin levels, the anticoagulation increased the risk of bleeding by 4times (HR 4.180, 1.955-8.937); p=0,001) and antiaggregation by almost 3times (HR 2.780, 1.257-6.149, p=0.012). A total of 64 cardiovascular events were registered, 21 of which were classified as atherosclerotic events: 10 in the antiaggregation group, 8in the control group and 3in the anticoagulation group (log rank: 8.351; p=0.015). Anticoagulation treatment showed a reduction in the risk of atherosclerotic events (HR 0.136, 0.033-0.551, p=0.005) while platelet antiaggregation did not modified this risk (HR 1,566, 0.569-4.308).

CONCLUSIONS

Anticoagulation and antiaggregation increase haemorrhagic risk in patients with CKD and worsen anaemia. Anticoagulation reduces atherosclerotic events by more than 85% while platelet antiaggregation does not modify this risk.

Anticoagulant Related Nephropathy Induced by Dabigatran

We describe a case of biopsy-proven dabigatran related nephropathy in a patient without underlying IgA nephropathy. To date, dabigatran related nephropathy was only reported in patients with concurrent or undiagnosed IgA nephropathy, suggesting that it may predispose patients to dabigatran associated injury. The patient is an 81-year-old woman with multiple medical comorbidities, including nonvalvular atrial fibrillation, who was anticoagulated with dabigatran. She presented to hospital with acute kidney injury in the setting of volume overload. Her estimated glomerular filtration rate decreased from a baseline of 57 mL/min/1.73 m² to 4 mL/min/1.73 m², necessitating hemodialysis. Renal ultrasound findings, fractional excretion of sodium, and urinalysis suggested acute kidney injury. Renal biopsy showed acute tubular injury, tubular red blood cell casts, and an absence of active glomerulonephritis, similar to the pathological findings of warfarin related nephropathy. A diagnosis of anticoagulant related nephropathy secondary to dabigatran was therefore established. This case demonstrates that dabigatran, like warfarin, may increase tubular bleeding risk in patients, irrespective of underlying kidney or glomerular disease.

Anticoagulant-Related Nephropathy

Anticoagulant-related nephropathy (ARN) is a newly recognized form of AKI in which overanticoagulation causes profuse glomerular hemorrhage, which manifests on renal biopsy as numerous renal tubules filled with red cells and red cell casts. The glomeruli show changes, but they are not sufficient to account for the glomerular hemorrhage. We were the first to study ARN, and since then, our work has been confirmed by numerous other investigators. Oral anticoagulants have been in widespread use since the 1950s; today, >2 million patients with atrial fibrillation take an oral anticoagulant. Despite this history of widespread and prolonged exposure to oral anticoagulants, ARN was discovered only recently, suggesting that the condition may be a rare occurrence. This review chronicles the discovery of ARN, its confirmation by others, and our animal model of ARN. We also provide new data on analysis of "renal events" described in the post hoc analyses of three pivotal anticoagulation trials and three retrospective analyses of large clinical databases. Taken together, these analyses suggest that ARN is not a rare occurrence in the anticoagulated patient with atrial fibrillation. However, much work needs to be done to understand the condition, particularly prospective studies, to avoid the biases inherent in post hoc and retrospective analyses. Finally, we provide recommendations regarding the diagnosis and management of ARN on the basis of the best information available.

Breadth of complications of long-term oral anticoagulant care

The majority of patients with venous thromboembolism (VTE) have a considerable long-term risk of recurrence and may require extended duration of anticoagulant treatment after the initial 3 to 6 months. The decision to extend treatment is based not only on the individual risk of recurrence, but should also consider the potential complications associated with anticoagulation, taking into account that anticoagulant drugs are among the drugs most frequently associated with hospital admission due to adverse drug reactions. The most feared complication of oral anticoagulants is bleeding, which in some cases may be fatal or may affect critical organs. Case-fatality rates of bleeding have been reported to be ∼3 times higher than case-fatality rates of recurrent VTE. Even when nonserious, bleeding may require medical intervention and/or may impact on patient quality of life or working activity. Factors associated with bleeding during anticoagulant treatment include, among others, advanced age, cancer, renal or liver insufficiency, or concomitant antithrombotic drugs, but no bleeding risk score is sufficiently accurate for use in clinical practice. Not uncommonly, bleeding occurs as a complication of trauma or medically invasive procedures. Nonbleeding complications associated with oral anticoagulants are unusual, and their relevance is extremely uncertain, and include vascular calcification, anticoagulation-related nephropathy, and osteoporosis. Finally, because VTE not uncommonly affects young individuals and the mean age of the population is ∼60 years, the costs associated with extended anticoagulation should not be forgotten. The costs of the drugs need to be balanced against health outcome costs associated with both recurrent VTE and bleeding.

Anticoagulant-related nephropathy: a pathological note

The wide employment of oral anticoagulants and the introduction of new anticoagulant agents highlight disparate kind of toxicities that can affect many different organ systems. Renal toxicity by oral anticoagulants is a well-known entity characterized by hematuria and the worsening of renal function associated with uncontrolled INR values. Although it is mainly a clinical diagnosis, renal biopsy may help especially in challenging cases when multiple comorbidities and underlying renal conditions exist. The mechanism of the anticoagulant-induced damage is still debated and special tissue stains (such as Perls') could help in detecting the direct tubular toxicity induced by chronic glomerular bleeding. The employment of a diagnostic clinic-pathological flow-chart can help in the prompt detection and full characterization of these cases, improving the management of the patient.

Bioptically Proven "Anticoagulation-Related Nephropathy" Induced by Dual Antiplatelet Therapy

Anticoagulation-related nephropathy (ARN) is a significant and underdiagnosed complication in patients who receive anticoagulation therapy. It is characterized by acute kidney injury in the setting of excessive anticoagulation defined as an international normalized ratio > 3.0 in patients treated with warfarin. A definitive diagnosis is made by renal biopsy showing acute tubular necrosis with obstruction of the tubuli by red blood cell casts. However, the evidence shows that ARN can occur during treatment with novel oral anticoagulants as well. Although it has been suggested that antiplatelet therapy, such as aspirin, might contribute to coagulopathy (and therefore the hypothetical risk of ARN), there are no reports of ARN induced by antiplatelet therapy according to our knowledge. It is also reported that glomerular lesions (i.e., kidney disease) represent a risk factor for ARN. We present a case of an 82-year-old man who developed biopsy-proven ARN after the administration of dual antiplatelet therapy with no previous anticoagulation treatment and normal coagulation tests.

Dabigatran-induced nephropathy and its successful treatment with Idarucizumab - case report and literature review

BACKGROUND

Anticoagulant induced renal injury has been previously described with Warfarin treatment. In the last decade direct oral anticoagulants (DOAC) were introduced. They include direct inhibitors of factor Xa (Rivaroxaban, Apixaban, Edoxaban) and a thrombin inhibitor (Dabigatran). There are isolated reports describing acute kidney injury (AKI) due to the use of DOACs.

CASE REPORT

We report a clinical case of an 80-year-old patient recently started on Dabigatran for new onset atrial fibrillation. She presented with AKI and hematuria, urine specimen showed RBC casts, and a working diagnosis of anticoagulant nephropathy due to Dabigatran was made. During hospitalization she was treated with Idarucizumab with a full recovery of renal function. To the best of our knowledge, there are 4 published case reports describing kidney injury produced by Dabigatran.

CONCLUSION

The use of DOACs is increasing rapidly, with increasing concern about its safety profile and, in particular, its potential harmful effect on renal function. As described in our case, treatment with Praxbind for Dabigatran induced kidney injury may be an acceptable management strategy that may obviate the need for urgent dialysis in selected cases by complete reversal of the AKI.