Safety and efficacy of apixaban versus vitamin K antagonists in patients undergoing dialysis: a systematic review and meta-analysis

BACKGROUND

This review aims to evaluate the safety and efficacy of apixaban vs. vitamin K antagonists (VKAs) in patients on dialysis.

METHODS

All types of studies published on PubMed, Embase, CENTRAL, and Web of Science up to 10 September 2023 and comparing outcomes of apixaban vs. VKA in dialysis patients were eligible.

RESULTS

Two randomized controlled trials (RCTs) and six retrospective studies were included. Apixaban treatment was associated with significantly lower risk of major bleeding (RR: 0.61; 95% CI: 0.48, 0.77; I2 = 50%) and clinically relevant non-major bleeding (RR: 0.82, 95% CI: 0.68, 0.98, I2 = 9%) compared to VKA. Meta-analysis also showed that the risk of gastrointestinal bleeding (RR: 0.74, 95% CI: 0.64, 0.85, I2 = 16%) and intracranial bleeding (RR: 0.64, 95% CI: 0.49, 0.84, I2 = 0%) was significantly reduced with apixaban. Meta-analysis showed no difference in the risk of ischemic stroke (RR: 0.40, 95% CI: 0.06, 2.69, I2 = 0%), mortality (RR: 1.26, 95% CI: 0.74, 2.16, I2 = 94%) and recurrent venous thromboembolism (RR: 1.02, 95% CI: 0.87, 1.21, I2 = 0%) between the two groups. Subgroup analysis of RCTs showed no difference in bleeding outcomes.

CONCLUSIONS

Low-quality evidence from a mix of RCTs and retrospective studies shows that apixaban may have better safety and equivalent efficacy as compared to VKA in dialysis patients. Apixaban treatment correlated with significantly reduced risk of major bleeding and clinically relevant nonmajor bleeding in observational studies but not in RCTs. The predominance of retrospective data warrants caution in the interpretation of results.

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

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

Management of patients with heart failure and chronic kidney disease

Chronic kidney disease (CKD) and heart failure are often co-existing conditions due to a shared pathophysiological process involving neurohormonal activation and hemodynamic maladaptation. A wide range of pharmaceutical and interventional tools are available to patients with CKD, consisting of traditional ones with decades of experience and newer emerging therapies that are rapidly reshaping the landscape of medical care for this population. Management of patients with heart failure and CKD requires a stepwise approach based on renal function and the clinical phenotype of heart failure. This is often challenging due to altered drug pharmacokinetics interactions with various degrees of kidney function and frequent adverse effects from the therapy that lead to poor patient tolerance. Despite a great body of clinical evidence and guidelines that have offered various treatment options for patients with heart failure and CKD, respectively, patients with CKD are still underrepresented in heart failure clinical trials, especially for those with advanced CKD and end-stage renal disease (ESRD). Future studies are needed to better understand the generalizability of these therapeutic options among heart failures with different stages of CKD.

Evaluation of Apixaban Use in Patients With Advanced Kidney Disease

Background: Current guidelines and literature suggest apixaban may be used in patients with severe kidney disease and atrial fibrillation (AF) for stroke and systemic embolism risk reduction (SSE) or patients with acute venous thromboembolism (VTE). Limited data is available for long-term safety and efficacy outcomes in this patient population. Objective: Evaluate the use of apixaban for AF or VTE in patients with advanced kidney disease. Methods: This single-center, retrospective, Investigational Review Board approved study evaluated patients ≥18 years of age with severe kidney disease on apixaban therapy for VTE or AF from March 1, 2018, to December 31, 2020. The primary outcome was major bleeding from apixaban initiation/continuation until 12 months after discharge. The secondary outcomes included a composite bleed (major bleeding, clinically relevant non-major bleeding, and minor bleeding), the occurrence of VTE or SSE, and death during hospitalization from any cause other than bleeding. Results: Overall, 156 patients met inclusion criteria. Six patients experienced major bleeding (3.8%). Composite bleeding occurred in 16 patients (10.3%); no patients had SSE or VTE, and 4 patients died from causes other than bleeding (2.6%). Limitations included the small sample size and retrospective nature of the study. Conclusion: This study demonstrated that patients with advanced chronic kidney disease on apixaban for AF or VTE had low major bleeding and similar overall bleeding rates compared with previously published literature. When considering the use of apixaban in this population, risks and benefits should be weighed in addition to the consideration of FDA-label dosing guidance.

Reprint of: Efficacy and safety of apixaban compared to warfarin for nonvalvular atrial fibrillation in end-stage renal disease on hemodialysis

BACKGROUND

This study compared the efficacy and safety of apixaban and warfarin in patients with nonvalvular atrial fibrillation (NVAF) and end-stage renal disease (ESRD) on hemodialysis (HD). Apixaban decreased incidence of stroke and bleeding compared with warfarin in major clinical trials that excluded patients with severe renal dysfunction. Apixaban is no longer contraindicated in patients with ESRD on HD with NVAF based on pharmacokinetic studies. Limited clinical data exist for patients with ESRD on HD on apixaban.

METHODS

A retrospective chart review was performed on patients with a diagnosis of NVAF and ESRD on HD who were prescribed apixaban or warfarin for stroke prevention in the years 2018 through 2019. Patients' charts were reviewed for up to a 2-year period. Patients on renal replacement therapy other than HD, those using anticoagulation for reasons other than NVAF, patients with Child-Pugh Class C cirrhosis, and those with severe mitral valve stenosis were excluded. The primary outcome was emergency department visits or hospital admissions for ischemic stroke or transient ischemic attack. Secondary outcomes included major or minor bleeding and adverse effects.

RESULTS

A total of 181 patients were screened; 110 patients met eligibility criteria and were included in the analysis. Four patients (7.5%) in the apixaban group and 6 patients (10.5%) in the warfarin group met the primary outcome of hospitalization or emergency department visit for stroke (P = 0.742). Symptomatic bleeding occurred in 39.6% of patients in the apixaban group and 36.8% in the warfarin group (P = 0.918). A trend in major bleeding occurred more often in the warfarin group, 52.4% versus 49.2% (P = 0.758).

CONCLUSIONS

There were no statistically significant differences in efficacy and safety outcomes between apixaban and warfarin in patients with NVAF and ESRD on HD in the intention-to-treat analysis of our study. Larger trials are needed to further analyze this patient population.

Meta-analysis evaluating apixaban in patients with atrial fibrillation and end-stage renal disease requiring dialysis

Background

Warfarin is considered the primary oral anticoagulant for patients with atrial fibrillation and end-stage renal disease (ESRD) requiring dialysis. Although warfarin can offer significant stroke prevention in this population, the accompanying major bleeding risks make warfarin nearly prohibitive. Apixaban was shown to be superior to warfarin in preventing stroke or systemic embolism, with a lower risk of bleeding and mortality in a large, randomized trial of individuals with mostly normal renal function but none with ESRD.

Methods

We systematically reviewed evidence comparing apixaban versus warfarin for atrial fibrillation in this population, and evaluated outcomes of stroke or systemic embolism, and major bleeding using random-effects models. The main safety outcome was major bleeding, and the main effectiveness outcome was stroke or systemic embolism.

Results

We found five observational studies of 10 036 patients (2638 receiving apixaban, and 7398 receiving warfarin) meeting inclusion criteria. Pooled analysis demonstrated a significant reduction in major bleeding with apixaban as compared to warfarin (odds ratio [OR] 0.51, 95% confidence interval [CI] 0.42-0.61; p < .0001). Apixaban was also associated with a reduction in intracranial bleeding (OR 0.58, 95% CI 0.37-0.92; p = .02) and in gastrointestinal bleeding (OR 0.61, 95% CI 0.51-0.73; p < .0001). Furthermore, apixaban was associated with a reduction in stroke/systemic embolism (OR 0.64, 95% CI 0.50-0.82; p < .0001).

Conclusion

Apixaban was associated with superior outcomes and reduced adverse events compared to warfarin in observational studies of patients with atrial fibrillation on dialysis. Randomized controlled studies are needed to confirm these findings.

Efficacy and safety of apixaban compared to warfarin for nonvalvular atrial fibrillation in end-stage renal disease on hemodialysis

BACKGROUND

This study compared the efficacy and safety of apixaban and warfarin in patients with nonvalvular atrial fibrillation (NVAF) and end-stage renal disease (ESRD) on hemodialysis (HD). Apixaban decreased incidence of stroke and bleeding compared with warfarin in major clinical trials that excluded patients with severe renal dysfunction. Apixaban is no longer contraindicated in patients with ESRD on HD with NVAF based on pharmacokinetic studies. Limited clinical data exist for patients with ESRD on HD on apixaban.

METHODS

A retrospective chart review was performed on patients with a diagnosis of NVAF and ESRD on HD who were prescribed apixaban or warfarin for stroke prevention in the years 2018 through 2019. Patients' charts were reviewed for up to a 2-year period. Patients on renal replacement therapy other than HD, those using anticoagulation for reasons other than NVAF, patients with Child-Pugh Class C cirrhosis, and those with severe mitral valve stenosis were excluded. The primary outcome was emergency department visits or hospital admissions for ischemic stroke or transient ischemic attack. Secondary outcomes included major or minor bleeding and adverse effects.

RESULTS

A total of 181 patients were screened; 110 patients met eligibility criteria and were included in the analysis. Four patients (7.5%) in the apixaban group and 6 patients (10.5%) in the warfarin group met the primary outcome of hospitalization or emergency department visit for stroke (P = 0.742). Symptomatic bleeding occurred in 39.6% of patients in the apixaban group and 36.8% in the warfarin group (P = 0.918). A trend in major bleeding occurred more often in the warfarin group, 52.4% versus 49.2% (P = 0.758).

CONCLUSIONS

There were no statistically significant differences in efficacy and safety outcomes between apixaban and warfarin in patients with NVAF and ESRD on HD in the intention-to-treat analysis of our study. Larger trials are needed to further analyze this patient population.

Effectiveness and safety of apixaban and rivaroxaban vs warfarin in patients with atrial fibrillation and chronic kidney disease

BACKGROUND

Randomized controlled trials (RCTs) of direct oral anticoagulants (DOACs) included a low proportion of atrial fibrillation (AF) patients with chronic kidney disease (CKD), and suggested that DOACs are safe and effective in patients with mild-to-moderate CKD. In a metanalysis of RCTs and observational studies, DOACs were associated with better efficacy (vs warfarin) in early CKD and had similar efficacy and safety profiles in patients with stages IV-V CKD. But few studies have provided data on the safety and effectiveness of each DOAC vs warfarin in patients with stage III CKD. The effectiveness and safety of DOACs in those patients are still subject to debate.

AIM

To assess and compare the effectiveness and safety of apixaban and rivaroxaban vs warfarin in this patient population.

METHODS

A cohort of patients with an inpatient or outpatient code for AF and stage III CKD who were newly prescribed apixaban and rivaroxaban was created using the administrative databases from the Quebec province of Canada between 2013 and 2017. The primary effectiveness outcome was a composite of ischemic stroke, systemic embolism, and death, whereas the primary safety outcome was a composite of major bleeding within a year of DOAC vs warfarin initiation. Treatment groups were compared in an under-treatment analysis using inverse probability of treatment weighting and Cox proportional hazards.

RESULTS

A total of 8899 included patients filled out a new oral anticoagulation therapy claim; 3335 for warfarin and 5564 for DOACs. Compared with warfarin, 15 mg and 20 mg rivaroxaban presented a similar effectiveness and safety composite risk. Apixaban 5.0 mg was associated with a lower effectiveness composite risk [Hazard ratio (HR) 0.76; 95% confidence interval (CI): 0.65-0.88] and a similar safety risk (HR 0.94; 95%CI: 0.66-1.35). Apixaban 2.5 mg was associated with a similar effectiveness composite (HR 1.00; 95%CI: 0.79-1.26) and a lower safety risk (HR 0.65; 95%CI: 0.43-0.99. Although, apixaban 5.0 mg was associated with a better effectiveness (HR 0.76; 95%CI: 0.65-0.88), but a similar safety risk profile (HR 0.94; 95%CI: 0.66-1.35). The observed improvement in the effectiveness composite for apixaban 5.0 mg was driven by a reduction in mortality (HR 0.61; 95%CI: 0.43-0.88).

CONCLUSION

In comparison with warfarin, rivaroxaban and apixaban appear to be effective and safe in AF patients with stage III CKD.

Associations of Apixaban Dose With Safety and Effectiveness Outcomes in Patients With Atrial Fibrillation and Severe Chronic Kidney Disease

BACKGROUND

Recommendations for apixaban dosing on the basis of kidney function are inconsistent between the US Food and Drug Administration and European Medicines Agency for patients with atrial fibrillation. Optimal apixaban dosing in chronic kidney disease remains unknown.

METHODS

With the use of deidentified electronic health record data from the Optum Labs Data Warehouse, patients with atrial fibrillation and chronic kidney disease stage 4/5 initiating apixaban between 2013 and 2021 were identified. Risks of bleeding and stroke/systemic embolism were compared by apixaban dose (5 versus 2.5 mg), adjusted for baseline characteristics by the inverse probability of treatment weighting. The Fine-Gray subdistribution hazard model was used to account for the competing risk of death. Cox regression was used to examine risk of death by apixaban dose.

RESULTS

Among 4313 apixaban new users, 1705 (40%) received 5 mg and 2608 (60%) received 2.5 mg. Patients treated with 5 mg apixaban were younger (mean age, 72 versus 80 years), with greater weight (95 versus 80 kg) and higher serum creatinine (2.7 versus 2.5 mg/dL). Mean estimated glomerular filtration rate was not different between the groups (24 versus 24 mL·min-1·1.73 m-2). In inverse probability of treatment weighting analysis, apixaban 5 mg was associated with a higher risk of bleeding (incidence rate 4.9 versus 2.9 events per 100 person-years; incidence rate difference, 2.0 [95% CI, 0.6-3.4] events per 100 person-years; subdistribution hazard ratio, 1.63 [95% CI, 1.04-2.54]). There was no difference between apixaban 5 mg and 2.5 mg groups in the risk of stroke/systemic embolism (3.3 versus 3.0 events per 100 person-years; incidence rate difference, 0.2 [95% CI, -1.0 to 1.4] events per 100 person-years; subdistribution hazard ratio, 1.01 [95% CI, 0.59-1.73]), or death (9.9 versus 9.4 events per 100 person-years; incidence rate difference, 0.5 [95% CI, -1.6 to 2.6] events per 100 person-years; hazard ratio, 1.03 [95% CI, 0.77-1.38]).

CONCLUSIONS

Compared with 2.5 mg, use of 5 mg apixaban was associated with a higher risk of bleeding in patients with atrial fibrillation and severe chronic kidney disease, with no difference in the risk of stroke/systemic embolism or death, supporting the apixaban dosing recommendations on the basis of kidney function by the European Medicines Agency, which differ from those issued by the US Food and Drug Administration.

Apixaban reduces the risk of major and clinically relevant non-major bleeding compared to warfarin in patients with end stage renal disease; a systematic review and meta-analysis of ten studies

Optimal anticoagulation in patients with end-stage renal disease ESRD is a matter of debate since these patients are not included in randomized controlled trials (RCTs). Evolving data are in favor of apixaban compared to warfarin.

METHODS

We extracted data from 2 RCTs, 5 retrospective cohort studies and 3 large data-based studies. Both dosing regimens of apixaban, standard or reduced, were accepted. In most studies characteristics of patients were balanced between arms. Patients with either atrial fibrillation (AF) or venous thromboembolism (VTE) were included. Quality of studies was graded as high and the funnel plot did not detect any publication bias. In total we analyzed the outcome of 6693 ESRD patients treated with apixaban and 19,836 treated with warfarin. Our analysis was performed by using the random effects model. We report our data as Risk Ratio (RR) and associated 95 % confidence interval values (95 %, CI).

RESULTS

The RR (95 % CI) of major bleeding was 0.69 (0.57-0.84) p = 0.0002 in favor of apixaban vs warfarin with heterogeneity to be statistically significant I2 63% p = 0.004. Meta-regression analysis with year of publication as moderator shows in bubble plotting that studies published earlier than 2018 were plotted as outliers. The RR (95 % CI) of clinically relevant non-major bleeding (CRNMB) was 0.74 (0.64-0.87) p = 0.0002 favoring again apixaban. Standard apixaban dose over reduced dose is less hemorrhagic compared to warfarin. Overall, in our study the risk of thrombosis in both arms was statistically non-different.

CONCLUSIONS

In our study we observed less hemorrhagic events with apixaban in ESRD patients compared to warfarin.

Bleeding Risk in Hemodialysis Patients

Cardiovascular diseases are highly prevalent among patients on dialysis. For these diseases, antiplatelets and antithrombotic therapies including heparin, vitamin K antagonists, and direct oral anticoagulants, are being used. However, the benefit-risk balance of these therapies could differ for dialysis patients compared with the general population. This review article focuses on the bleeding risk associated with the use of heparin, antiplatelets, vitamin K antagonists, and direct oral anticoagulants in patients receiving hemodialysis.

Safety and efficacy of apixaban versus low-molecular weight heparin or vitamin-K antagonists for venous thromboembolism treatment in patients with severe renal failure: A systematic review and meta-analysis

INTRODUCTION

Chronic kidney disease is an independent risk factor for venous thromboembolism (VTE). Traditionally, Low Molecular Weight Heparin (LMWH) followed by warfarin has been the conventional therapy for VTE treatment. Direct oral anticoagulants (DOACs), including apixaban, have shown several advantages over the traditional therapy in individuals with normal kidney function. This meta-analysis aims to review the safety and efficacy of apixaban compared to warfarin or LMWH for the treatment of VTE in severe renal failure.

METHOD

We conducted literature search in PubMed, Embase, and Cochrane databases. Retrospective observational studies involving clinical effectiveness and safety outcomes of apixaban compared to warfarin in adult patients with an estimated glomerular filtration rate (eGFR) <30 mL/min/m2 or on dialysis were included.

RESULTS

Eight studies were included in the analysis. Significant reduction in VTE recurrence observed in apixaban compared to warfarin (RR, 0.65; 95 % CI, 0.43-0.98; P = 0.04; I2 = 78 %). No significant difference in all-cause mortality between apixaban and warfarin (RR, 0.99; 95 % CI, 0.91-1.07; P = 0.74; I2 = 0 %). Apixaban showed a significantly lower rate of major bleeding (RR, 0.72; 95 % CI, 0.62-0.84; P < 0.0001; I2 = 34 %) and minor bleeding events (RR, 0.42; 95 % CI, 0.21-0.86; P = 0.02; I2 = 10 %) compared to warfarin. No significant difference observed in clinically relevant non-major bleeding between apixaban and warfarin (RR, 0.81; 95 % CI, 0.65-1.00; P = 0.05; I2 = 67 %).

CONCLUSION

Apixaban was favored over warfarin for treating VTE in severe renal failure, reducing VTE recurrence and bleeding risk. No differences were observed in all-cause mortality and CRNMB events. More evidence is required due to limited RCTs and prospective studies.

Effectiveness and safety of direct oral anticoagulants in patients with venous thromboembolism and creatinine clearance < 30 mL/min

The few studies that compared direct oral anticoagulants (DOAC) vs. warfarin in the setting of advanced renal insufficiency have focused on patients with atrial fibrillation. The purpose of this observational, matched, cohort study of patients was to assess the effectiveness and safety of DOAC vs. warfarin for the treatment of venous thromboembolism (VTE) among patients with a creatinine clearance (CrCl) < 30 mL/min. This observational, cohort study included patients with VTE and CrCl < 30 mL/min who were newly initiated on a DOAC or warfarin between January 1, 2016 and December 31, 2020. DOAC patients were matched up to 1:2 to warfarin patients. Primary outcome was a composite of recurrent VTE, clinically-relevant bleeding, ischemic stroke, and all-cause mortality. Adjusted conditional, multivariate Cox proportional hazards modeling was used to assess outcomes. 626 DOAC patients were matched to 1071 warfarin patients. DOAC patients had a higher mean age, higher mean baseline CrCl, and were less likely to have been receiving dialysis. There was no statistically significant difference in the composite outcome between groups (adjusted hazard ratio [aHR] 1.13, 95% confidence interval [CI] 0.87-1.47) or in the individual components of the composite (all HR 95% CI crossed 1.00). Identification of statistically non-significant rates of bleeding and thromboembolic outcomes suggest that the use of DOAC or warfarin is reasonable in patients with VTE and CrCl < 30 mL/min.

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.

Evaluation of standard versus reduced dose apixaban for the treatment of venous thromboembolism in patients with severe renal disease (ESRD-VTE)

BACKGROUND

There are no clear dosing recommendations when using apixaban for venous thromboembolism (VTE) treatment in patients with severe or end-stage renal disease; clinical trials excluded patients with a creatinine clearance (CrCl) <25 mL/min or on dialysis. This study compares bleeding rates in patients with severe or end-stage renal disease taking standard versus reduced dose apixaban for VTE treatment.

MATERIALS AND METHODS

This was a multicenter, retrospective cohort study using electronic medical records between January 1, 2013, and August 31, 2021. This study included patients 18 years or older who had severe or end-stage renal disease when prescribed apixaban for VTE treatment. Severe or end-stage renal disease was defined as at least one of the following: CrCl <25 mL/min, SCr >2.5 mg/dL, CKD stage 4 or 5, or on dialysis. The primary endpoint was rate of clinically relevant bleeding within six months of starting apixaban. Secondary endpoints were VTE recurrence within six months of starting apixaban, time to clinically relevant bleed, and time to VTE recurrence.

RESULTS

A total of 203 patients were included in the final analysis (n = 125 on 5 mg; n = 78 on 2.5 mg). Clinically relevant bleeding rate was significantly higher in the standard dose group (14.4 % vs 3.8 %, p = 0.02). Rates of VTE recurrence appear similar (6.4 % vs 7.7 %, p = 0.21).

CONCLUSIONS

A reduced dose of apixaban may be considered when treating VTE in patients with severe or end-stage renal disease.

A systematic review of the efficacy and safety of anticoagulants in advanced chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) have an increased risk of venous thromboembolism (VTE) and atrial fibrillation (AF). Anticoagulants have not been studied in randomised controlled trials with CrCl < 30 ml/min. The objective of this review was to identify the impact of different anticoagulant strategies in patients with advanced CKD including dialysis.

METHODS

We conducted a systematic review of randomized controlled trials and cohort studies, searching electronic databases from 1946 to 2022. Studies that evaluated both thrombotic and bleeding outcomes with anticoagulant use in CrCl < 50 ml/min were included.

RESULTS

Our initial search yielded 14,503 papers with 53 suitable for inclusion. RCTs comparing direct oral anticoagulants (DOACs) versus warfarin for patients with VTE and CrCl 30-50 ml/min found no difference in recurrent VTE events (RR 0.68(95% CI 0.42-1.11)) with reduced bleeding (RR 0.65 (95% CI 0.45-0.94)). Observational data in haemodialysis suggest lower risk of recurrent VTE and major bleeding with apixaban versus warfarin. Very few studies examining outcomes were available for therapeutic and prophylactic dose low molecular weight heparin for CrCl < 30 ml/min. Findings for patients with AF on dialysis were that warfarin or DOACs had a similar or higher risk of stroke compared to no anticoagulation. For patients with AF and CrCl < 30 ml/min not on dialysis, anticoagulation should be considered on an individual basis, with limited studies suggesting DOACs may have a preferable safety profile.

CONCLUSION

Further studies are still required, some ongoing, in patients with advanced CKD (CrCl < 30 ml/min) to identify the safest and most effective treatment options for VTE and AF.

Nonvalvular atrial fibrillation in patients undergoing chronic hemodialysis. Should dialysis patients with atrial fibrillation receive oral anticoagulation?

Chronic kidney disease (CKD) is an independent risk factor for presenting atrial fibrillation (AF), which conditions an increased risk already present in CKD of suffering a thromboembolic event. And this risk is even higher in the hemodialysis (HD) population. On the other hand, in CKD patients and even more so in HD patients, the probability of suffering serious bleeding is also higher. Therefore, there is no consensus on whether or not to anticoagulate this population. Taking as a model what is advised for the general population, the most common attitude among nephrologists has been to opt for anticoagulation, even though there is no randomized studies to support it. Classically, anticoagulation has been done with vitamin K antagonists, at high cost for our patients: severe bleeding events, vascular calcification, and progression of nephropathy, among other complications. With the emergence of direct-acting anticoagulants, a hopeful outlook was opened in the field of anticoagulation, as they were postulated as more effective and safer drugs than antivitamin K. However, in clinical practice, this has not been the case. In this paper we review various aspects of AF and its anticoagulant treatment in the HD population.

Safety and effectiveness of apixaban versus warfarin for acute venous thromboembolism in patients with end-stage kidney disease: A national cohort study

BACKGROUND

Patients with end-stage kidney disease (ESKD) are at significantly increased risk for both thrombosis and bleeding relative to those with normal renal function. The optimal therapy of venous thromboembolism (VTE) in patients with ESKD is unknown.

OBJECTIVE

To compare the safety and effectiveness of apixaban relative to warfarin in patients with ESKD and acute VTE.

DESIGN, SETTING AND PARTICIPANTS

New-user, active-comparator retrospective United States population-based cohort with inverse probability of treatment weighting, using the United States Renal Data System data from 2014 to 2018. We included adults with ESKD on hemodialysis or peritoneal dialysis who were newly initiated on apixaban or warfarin for an acute VTE.

MAIN OUTCOME AND MEASURES

The coprimary outcomes were major bleeding, recurrent VTE, and all-cause mortality within 6 months of anticoagulant initiation. Secondary outcomes were intracranial hemorrhage and gastrointestinal bleeding. The primary analyses were based on intent-to-treat defined by the first drug received and accounted for competing risks of death. Sensitivity analyses included varied follow-up time, as-treated analyses, and dose-specific apixaban subgroups.

RESULTS

The apixaban and warfarin cohorts included 2302 and 9263 patients, respectively. Apixaban was associated with a lower risk of major bleeding (hazard ratio [HR] 0.81, 95% confidence interval [CI]: 0.70-0.94), intracranial bleeding (HR 0.69, 95% CI 0.48-0.98), and gastrointestinal bleeding (HR 0.82, 95% CI 0.69-0.96). Recurrent VTE and all-cause mortality were not significantly different between the groups.

CONCLUSION

Apixaban was associated with a lower risk of bleeding relative to warfarin when used to treat acute VTE in patients with ESKD on dialysis.

Safety and Efficacy of Apixaban vs Warfarin in Patients With Stage 4 and 5 Chronic Kidney Disease: A Systematic Review

Warfarin has been an anticoagulant of choice in patients with advanced Chronic Kidney Diseases (CKD) at stages 4 and 5 for decades, but with the advent of Novel Oral Anticoagulants (NOACs), there has been a sharp rise in their prescriptions. Among all NOACS, apixaban is the least reliant on kidney function and is a very popular choice for this patient population. However, being utilized extensively, most of the landmark trials evaluating the safety and efficacy of apixaban excluded patients with Creatinine Clearance (CrCl) <25mL/min/1.73 m² or Serum Creatinine (SCr) ≥2.5mg/dL. Its approval for advanced CKD patients came from limited pharmacokinetic data only. We conducted a systematic review comparing the safety and efficacy of apixaban to warfarin in patients with stage 4 and 5 CKD and on dialysis. We queried major research literature databases, including MEDLINE, PubMed, PubMed Central (PMC), Cochrane Central, and ScienceDirect to find relevant articles without any time or language restrictions. After screening and quality checks, we identified 11 studies relevant to our research question, of which nine were retrospective cohort studies, one was a post-hoc analysis of a randomized controlled trial (RCT), and one was an RCT. The included studies had a total of 27,007 patients, with 4,335 patients taking apixaban and 22,672 on warfarin. The results indicate that the overall efficacy of apixaban was equivalent to warfarin for the prevention of stroke, systemic embolization, and recurrent venous thromboembolism, but apixaban showed an equivalent and, in some studies, better safety profile than warfarin concerning the occurrence of bleeding. Apixaban may hence be considered a reasonable alternative to warfarin in patients with Stage 4 or 5 CKD and receiving dialysis. In light of the reviewed articles, we conclude that apixaban has similar efficacy and somewhat superior safety profile to warfarin, with more randomized controlled trials required to add to the evidence.

Stroke Prevention in Atrial Fibrillation: A Scientific Statement of JACC: Asia (Part 2)

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with substantial increases in the risk for stroke and systemic thromboembolism. With the successful introduction of the first non-vitamin K antagonistdirect oral anticoagulant agent (NOAC) in 2009, the role of vitamin K antagonists has been replaced in most clinical settings except in a few conditions for which NOACs are contraindicated. Data for the use of NOACs in different clinical scenarios have been accumulating in the past decade, and a more sophisticated strategy for patients with AF is now warranted. JACC: Asia recently appointed a working group to summarize the most updated information regarding stroke prevention in AF. The aim of this statement is to provide possible treatment options in daily practice. Local availability, cost, and patient comorbidities should also be considered. Final decisions may still need to be individualized and based on clinicians' discretion. This is part 2 of the statement.

Venous thromboembolic complications in patients with chronic kidney disease: prevalence and features of drug treatment

The article is an opinion on the problem of venous thromboembolic (VTE) complications in patients with chronic kidney disease (CKD), which is significant and urgent for Russia. Signs of CKD are noted in more than 1/3 of patients with chronic heart failure; a decrease in kidney function is observed in 36% of people over the age of 60, in people of working age, a decrease in function is noted in 16% of cases, and in the presence of cardiovascular diseases increases to 26%. Clinical research data convincingly show that CKD is an independent risk factor for the development of VTE complications. The last decade has given us the opportunity to observe a kind of "revolution" in VTE therapy, which is associated with the appearance on the market of direct oral anticoagulants, including inhibitors of factor IIa (thrombin) and factor Xa. These drugs are approved by the Food and Drug Administration for the treatment of acute thromboembolism. Nevertheless, patients with severe CKD (estimated glomerular filtration rate 30 ml/min) are still limited to the use of unfractionated heparin and vitamin K antagonists, as there is insufficient data to support the use of direct oral anticoagulants in this population.

Antithrombotic Therapy for Chronic Kidney Disease Patients With Concomitant Atrial Fibrillation and Coronary Artery Disease

Background: Oral anticoagulants (OAC) plus antiplatelets is recommended for patients with atrial fibrillation (AF) and coronary artery disease (CAD) to reduce thromboembolism. However, there is limited evidence regarding antithrombotic therapy for patients with concomitant chronic kidney disease (CKD), AF, and CAD, especially those not undergoing percutaneous coronary intervention. We aimed to use real-world data assessing the efficacy and safety of antithrombotic regimens in this population.

Methods: We used a single-center database of 142,624 CKD patients to identify those receiving antithrombotic therapy for AF and CAD between 2010 and 2018. Patients taking warfarin or direct OAC (DOAC) alone were grouped in the OAC monotherapy (n = 537), whereas those taking OAC plus antiplatelets were grouped in the combination therapy (n = 2,391). We conducted propensity score matching to balance baseline covariates. The endpoints were all-cause mortality, major adverse cardiovascular events, and major bleedings.

Results: After 1:4 matching, the number of patients in OAC monotherapy and combination therapy were 413 and 1,652, respectively. Between the two groups, combination therapy was associated with higher risks for ischemic stroke (HR 2.37, CI 1.72–3.27), acute myocardial infarction (HR 6.14, CI 2.51–15.0), and hemorrhagic stroke (HR 3.57, CI 1.35–9.81). The results were consistent across CKD stages. In monotherapy, DOAC users were associated with lower risks for all-cause mortality, AMI, and gastrointestinal bleeding than warfarin, but the stroke risk was similar between the two subgroups.

Conclusions: For patients with concomitant CKD, AF and CAD not undergoing PCI, OAC monotherapy may reduce stroke and AMI risks. DOAC showed more favorable outcomes than warfarin.

Off-Label Underdosing or Overdosing of Non-vitamin K Antagonist Oral Anticoagulants in Patients With Atrial Fibrillation: A Meta-Analysis

Background: Several studies have investigated the role of off-label non-vitamin K antagonist oral anticoagulants (NOACs) in patients with atrial fibrillation (AF). We aimed to compare the effectiveness and safety outcomes between off-label underdose or overdose vs. on-label dose of NOACs in AF patients.

Methods: The PubMed database was systematically searched until August 2021. Observational cohorts were included if they compared the outcomes of off-label underdose or overdose with on-label dose of NOACs in AF patients. The risk ratios (RRs) and 95% confidence intervals (CIs) were pooled using a fixed-effects model (I² ≤ 50%) or a random-effects model (I² > 50%).

Results: A total of 15 observational studies were included. Compared with on-label dose of NOACs, off-label underdose of NOACs was associated with increased risks of stroke or systemic embolism (RR = 1.09, 95% CI 1.02–1.16), and all-cause death (RR = 1.29, 95% CI 1.10–1.52) but not ischemic stroke (RR = 1.34, 95% CI 0.76–2.36), myocardial infarction (RR = 1.08, 95% CI 0.92–1.28), major bleeding (RR = 0.97, 95% CI 0.89–1.05), intracranial hemorrhage (RR = 1.12, 95% CI 0.90–1.40), and gastrointestinal bleeding (RR = 0.96, 95% CI 0.85–1.07), whereas off-label overdose of NOACs was associated with increased risks of SSE (RR = 1.20, 95% CI 1.05–1.36), all-cause death (RR = 1.22, 95% CI 1.06–1.39), and major bleeding (RR = 1.33, 95% CI 1.16–1.52) but not gastrointestinal bleeding (RR = 1.18, 95% CI 0.99–1.42) and myocardial infarction (RR = 0.98, 95% CI 0.75–1.30).

Conclusion: Compared with on-label dose of NOACs, off-label underdose was associated with increased risks of stroke or systemic embolism and all-cause death, whereas off-label overdose of NOACs was associated with increased risks of stroke or systemic embolism, all-cause death, and major bleeding.

Non-valvular Atrial Fibrillation in CKD: Role of Vitamin K Antagonists and Direct Oral Anticoagulants. A Narrative Review

Atrial fibrillation (AF) is the most common arrhythmia in chronic kidney disease (CKD), with a close bidirectional relationship between the two entities. The presence of CKD in AF increases the risk of thromboembolic events, mortality and bleeding. Vitamin K antagonists (VKA) have been the mainstay of treatment for the prevention of thromboembolic events in AF until recently, with confirmed benefits in AF patients with stage 3 CKD. However, the risk-benefit profile of VKA in patients with AF and stages 4-5 CKD is controversial due to the lack of evidence from randomized controlled trials. Treatment with VKA in CKD patients has been associated with conditions such as poorer anticoagulation quality, increased risk of bleeding, faster progression of vascular/valvular calcification and higher risk of calciphylaxis. Direct oral anticoagulants (DOACs) have shown equal or greater efficacy in stroke/systemic embolism prevention, and a better safety profile than VKA in post-hoc analysis of the pivotal randomized controlled trials in patients with non-valvular AF and stage 3 CKD, yet evidence of its risk-benefit profile in more advanced stages of CKD is scarce. Observational studies associate DOACs with a good safety/effectiveness profile compared to VKA in non-dialysis CKD patients. Further, DOACs have been associated with a lower risk of acute kidney injury and CKD development/progression than VKA. This narrative review summarizes the evidence of the efficacy and safety of warfarin and DOACs in patients with AF at different CKD stages, as well as their effects on renal function, vascular/valvular calcification and bone health.

Can direct oral anticoagulants be used in kidney transplant recipients?

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Relation of apixaban bleeding rates to dose in patients with chronic kidney disease

The objective of this study was to evaluate the safety and efficacy of apixaban 5 mg twice daily vs 2.5 mg twice daily for nonvalvular atrial fibrillation or venous thromboembolism in patients with chronic kidney disease stage 4 and 5, including those on hemodialysis. Data were collected retrospectively on patients with advanced chronic kidney disease and nonvalvular atrial fibrillation and/or venous thromboembolism who received apixaban while hospitalized at our institution between January 2013 and August 2018. The 5 mg twice daily group included 22 patients, and the 2.5 mg twice daily group included 73 patients. There was no difference between groups in major bleeding events (9.1% vs. 12.3%, P = 1.00), any bleeding event (45.4% vs. 67.1%, P = 0.08), ischemic stroke (0% vs. 2.7%, P = 1.00), or venous thromboembolism (4.5% vs. 0%, P = 0.23). Subgroup analyses of patients with a serum creatinine >2.5 mg/dL or creatinine clearance <25 mL/min and patients on hemodialysis produced similar results. Until larger trials are conducted, clinicians should make patient-specific decisions about the optimal dose of apixaban in patients with severe renal impairment.

Direct oral anticoagulant use in special populations

PURPOSE OF REVIEW

The pivotal phase III trials demonstrating efficacy and safety of direct oral anticoagulants (DOACs) in the treatment of venous thromboembolism (VTE) or nonvalvular atrial fibrillation (NVAF) excluded patients with important and common comorbidities, including obesity, advanced chronic kidney disease, cirrhosis, cancer and antiphospholipid antibody syndrome. Despite the lack of large prospective randomized control trials in these patient populations, the use of DOACs has led to a wealth of efficacy and safety data within these groups.

RECENT FINDINGS

Retrospective studies, meta-analyses, national databases and pharmacokinetic data have shed light on the efficacy and safety of DOACs in these patient populations. Although DOACs should be avoided in those with high-risk triple positive antiphospholipid antibody syndrome, advanced cirrhosis, advanced kidney disease and intact gastrointestinal cancers, and used with caution in genitourinary cancers, their use extends beyond the inclusion criteria of the initial randomized control trials.

SUMMARY

DOACs have revolutionized anticoagulant management and have become the cornerstone for VTE treatment and stroke prevention in NVAF. The decision to use DOACs must be individualized. Patient preference, underlying comorbidities and informed consent must always be considered when selecting the most appropriate anticoagulant.

Outcomes associated with apixaban vs warfarin in patients with renal dysfunction

Apixaban in patients with impaired renal function is supported by limited data. Landmark clinical trials evaluating apixaban in patients with atrial fibrillation and/or acute venous thromboembolism excluded patients with creatinine clearance (CrCl) <25 mL/min. This multicenter, retrospective chart review was conducted to evaluate the safety and effectiveness of apixaban compared with warfarin in patients with CrCl <25 mL/min. Included patients were newly initiated on apixaban or warfarin for at least 45 days with a CrCl <25 mL/min. Patients were evaluated for thrombosis and bleeding outcomes 6 months following initiation of anticoagulation. The primary outcome was the time to first bleeding or thrombosis event. A total of 128 patients met inclusion criteria in the apixaban group and 733 patients in the warfarin group. Time to first bleeding or thrombosis event was significantly different between the apixaban and warfarin groups. Cox proportional hazards model was conducted to control for potential confounding factors for the primary outcome. After controlling for atrial fibrillation and coronary artery bypass grafting, risk of thrombotic and bleeding events was lower in the apixaban group (hazard ratio, 0.47; 95% confidence interval, 0.25-0.92). There was not a statistical difference between time to thrombosis (83 days vs 54 days, P = .648), rate of thrombosis (5.5% vs 10.3%, P = .08), time to bleeding (46 days vs 54 days, P = .886), or rate of bleeding (5.5% vs 10.9%, P = .06). The severity of bleeding and thrombotic events was not different between groups. Apixaban may serve as a reasonable alternative compared with warfarin in patients with severe renal dysfunction.

Apixaban anti-Xa level monitoring in treatment of acute upper extremity deep vein thrombosis for patient on chronic hemodialysis: a case report

Background

Patients on dialysis are at higher risk of major bleeding and recurrent thrombosis creating acute venous thromboembolism (VTE) treatment challenges. DOACs represent an interesting option but there are concerns of bioaccumulation and increased bleeding risk. Anti-Xa trough levels may be used to monitor for bioaccumulation but there is little data.

Case presentation

We describe a case, a 51 yo female, 36 kg on hemodialysis with a provoked acute upper extremity deep vein thrombosis in whom body habitus and calciphylaxis contraindicated the use of standard therapy. She received apixaban 2.5 mg twice daily for 6 weeks. The apixaban anti-Xa trough levels were measured weekly 12 h after the morning dose and ranged from 58 to 84 ng/mL, similar to expected levels with normal renal function. There were no adverse events in the 3 months follow-up.

Conclusions

We saw no evidence of bioaccumulation indicating a potential role for low dose apixaban for acute VTE in dialysis patients.

Efficacy and Safety of Direct Oral Anticoagulants vs Warfarin in Patients with Chronic Kidney Disease and Dialysis Patients: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE: Systematic reviews and meta-analyses of direct oral anticoagulants (DOACs) for patients with chronic kidney disease (CKD) or dialysis patients are lacking. We aimed to compare the efficacy and safety of DOACs and warfarin in patients with CKD requiring anticoagulation therapy.

METHODS

We performed a systematic review and meta-analysis of six randomized controlled trials and 19 observational studies, with the inclusion criteria being a comparative study between DOACs and warfarin in patients with CKD or dialysis patients from database inception until August 2020. The efficacy outcomes were stroke, systemic embolism (SE), or venous thromboembolism (VTE), and the safety outcome was major bleeding.

RESULTS

Compared with warfarin, DOACs significantly reduced the risk of stroke/SE/VTE by 22% (hazard ratio [HR] = 0.78, 95% confidence interval [CI] 0.64-0.95) and major bleeding by 17% (HR = 0.83, 95% CI 0.71-0.97). On comparing factor Xa inhibitors and dabigatran with warfarin separately, factor Xa inhibitors significantly reduced the risk of stroke/SE/VTE (HR = 0.78, 95% CI 0.62-0.98) and major bleeding (HR = 0.76, 95% CI 0.64-0.91) overall in patients. Comparing each DOACs with warfarin separately, apixaban was associated with a significantly better risk reduction of stroke/SE/VTE (25% risk reduction) and major bleeding (35% risk reduction) than warfarin. Compared with warfarin, DOACs significantly reduced the risk of stroke, SE, or VTE by 19% (HR = 0.81, 95% CI 0.68-0.97) in patients with CKD stage 3 and significantly lowered the risk of major bleeding by 31% (HR = 0.69, 95% CI 0.56-0.85) in patients with CKD stages 4-5.

CONCLUSIONS

In pooled, analyzed randomized controlled trials and observational studies, DOACs were associated with better efficacy in early CKD, as well as similar efficacy and safety outcomes to warfarin in patients with CKD stages 4-5 or dialysis patients. The results of patients with CKD stages 4-5 and dialysis patients were from observational studies. Well-designed randomized controlled trials focused on DOAC use in patients with CKD and dialysis patients are needed. PROSPERO register number: CRD42020150599, 6 February, 2020.

Safety of apixaban compared to warfarin in hemodialysis patients: Do antiplatelets make a difference?

BACKGROUND

Data on the safety of apixaban compared to warfarin in hemodialysis (HD) patients are accumulating, but the impact of concomitant antiplatelet use is unknown.

OBJECTIVES

Compare hemorrhagic risk and impact of antiplatelets in HD patients receiving oral anticoagulants (OAC).

METHODS

Retrospective, multi-center study of HD patients started on OAC inpatient over 5 years.

RESULTS

707 patients were included: 563 received warfarin, and 144 received apixaban. 197 had bleeding, most in the warfarin group (173 [30.1%] vs 24 [16.7%] in the apixaban group), P-value < .01). However, with concomitant antiplatelet use, frequencies were similar (31.4% vs 25.0%; P-value = .292). Cumulative incidence using bleeding as event of interest and death as competing risk showed higher rates of bleeding with warfarin. In a multivariate model, apixaban was associated with a lower hemorrhagic risk (hazard ratio [HR] 0.55 [95% confidence interval {CI} 0.35-0.86}). Apixaban showed lower hemorrhagic risk alone (HR 0.24, 95% CI 0.10-0.55) and similar risk when administered with antiplatelets (HR 0.93, 95% CI 0.55-1.56).

CONCLUSIONS

Apixaban is associated with less bleeding in HD patients compared to warfarin, but concomitant antiplatelet use may negate the safety advantage. Prospective trials are warranted to determine the impact of antiplatelets on apixaban safety.

Direct Oral Anticoagulant Use in Special Populations: Elderly, Obesity, and Renal Failure

PURPOSE OF REVIEW

The purpose of this review is to examine the safety and effectiveness of direct oral anticoagulants and provide recommendations for the treatment of venous thromboembolism and atrial fibrillation in obese patients, elderly patients, and patients with chronic kidney disease.

RECENT FINDINGS

Multiple retrospective cohort studies have shown no difference in bleeding, stroke, or venous thromboembolism outcomes between DOACs and warfarin in patients who are obese, elderly, or those with chronic kidney disease or on dialysis. Some studies have shown that DOACs have a lower bleeding risk than warfarin in these populations. DOACs may be a safe and effective alternative to warfarin for the prevention of stroke in atrial fibrillation patients who are obese, elderly, or those with chronic kidney disease or on dialysis. Apixaban may improve clinical outcomes by lowering the risk of bleeding versus warfarin. DOACs may also be an effective and safe alternative to warfarin for the treatment of venous thromboembolism in obese patients; however, additional studies are needed to assess their use in elderly patients and those with CKD.

Oral anticoagulation in chronic kidney disease with atrial fibrillation

Chronic kidney disease (CKD) and atrial fibrillation (AF) frequently coexist, amplifying the risk of cardiovascular events and mortality. In patients with CKD stage 3 and non-valvular AF, direct oral anticoagulants (DOACs) have shown, compared to vitamin K antagonists (VKA), equal or greater efficacy in the prevention of stroke and systemic embolism, and greater safety. There are no randomizedtrials of the efficacy and safety of DOACs and VKA in advanced CKD. On the other hand, observational studies suggest that DOACs, compared to warfarin, are associated with a lower risk of acute kidney damage and generation/progression of CKD. This paper reviews the epidemiological and pathophysiological aspects of the CKD and AF association, the evidence of the efficacy and safety of warfarin and ACODs in various stages of CKD with AF as well as the comparison between warfarin and ACODs in efficacy and anticoagulant safety, and in its renal effects.

Direct Oral Anticoagulants in the Treatment of Venous Thromboembolism: Use in Patients with Advanced Renal Impairment, Obesity, or Other Weight-Related Special Populations

There are currently more than 7 million patients taking a direct oral anticoagulant (DOAC), with more new prescriptions per year than warfarin. Despite impressive efficacy and safety data for the treatment of venous thromboembolism, patients with obesity or advanced renal impairment represented a small portion of the patients enrolled in the phase 3 clinical trials. Therefore, to evaluate the potential use of DOACs in these special populations, clinicians need to have an understanding of the pharmacokinetics and pharmacodynamics of these agents in these settings. Since data from randomized controlled trials are limited, data from observational trials are helpful in gaining comfort with the use of DOACs in these special populations. Selecting the appropriate dose for each agent is imperative in achieving optimal patient outcomes. We provide an extensive review of the pharmacokinetics, pharmacodynamics, phase 3 clinical trials, and observational studies on the use of DOACs in patients with advanced renal impairment, obesity, or other weight-related special populations to provide clinicians with a comprehensive understanding of the data for optimal drug and dose selection.

Effect of Rivaroxaban or Apixaban in Atrial Fibrillation Patients with Stage 4-5 Chronic Kidney Disease or on Dialysis

BACKGROUND

Anticoagulant treatment in non-valvular atrial fibrillation (AF) patients with severe chronic kidney disease (CKD) or on dialysis remains a matter of debate. The object of this study was to quantify the benefit-risk profiles of rivaroxaban or apixaban versus warfarin in AF patients with stage 4-5 CKD or on dialysis.

METHOD

A comprehensive search of the Cochrane Library, PubMed, Ovid, and Google Scholar databases was performed for eligible studies that comparing the effect and safety of rivaroxaban or apixaban versus warfarin in AF patients with stage 4-5 CKD or on dialysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were abstracted, and then pooled using a random-effects model.

RESULTS

A total of seven studies, one post hoc analysis of RCT and six observational cohorts, were included in this meta-analysis. Compared with warfarin use, the use of rivaroxaban or apixaban was significantly associated with reduced risks of all-cause death (HR = 0.82, 95% CI 0.72-0.93) and gastrointestinal bleeding (HR = 0.87, 95% CI 0.80-0.95). There were no significant differences in the risks of stroke or systemic embolism (rivaroxaban, HR = 0.71, 95% CI 0.43-1.19; apixaban, HR = 0.86, 95%CI 0.68-1.09) and major bleeding (rivaroxaban, HR = 0.96, 95% CI 0.64-1.45; apixaban, HR = 0.56, 95%CI 0.28-1.12).

CONCLUSIONS

Current evidence suggests that rivaroxaban or apixaban are safe and at least as effective as warfarin in patients with AF and stage 4-5 CKD or on dialysis.

Clinical controversies in the treatment of cancer-associated venous thromboembolism

Cancer-associated venous thromboembolism (VTE) is a common complication of malignancy. Patients with cancer exhibit risk factors for both recurrent VTE and major or minor bleeding. Direct oral anticoagulants (DOACs) are an attractive treatment option; however, there is a lack of consensus among national guidelines for choice between DOACs and LMWH, agent selection, dosing strategy, and duration of anticoagulation. Characteristics of the thrombotic event, the malignancy, the patient, and the anticoagulant must be considered. A systematic search of online databases was performed to identify literature on the management of cancer-associated VTE. Multiple controversies remain surrounding the optimal treatment of cancer-associated VTE.

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION AND DATA EXTRACTION

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

DATA SYNTHESIS

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

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

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

CONCLUSION

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

Position paper on the safety/efficacy profile of direct oral anticoagulants in patients with chronic kidney disease. Consensus document from the SIN, FCSA and SISET

Direct oral anticoagulants (DOAC) are mostly prescribed to prevent cardioembolic stroke in patients with non-valvular atrial fibrillation (AF). An increasing number of guidelines recommend DOAC in AF patients with preserved renal function for the prevention of thromboembolism, and an increased use of DOAC in daily practice has been recorded also in elderly patients. Ageing is associated with a reduction in glomerular filtration rate, and impaired renal function, regardless of the cause, increases the risk of bleeding. Multiple medication use (polypharmacy) for treating superimposed co-morbidities is common in both elderly and chronic kidney disease (CKD) patients and drug-drug interaction may cause accumulation of DOAC, thereby increasing the risk of bleeding. The safety profile of DOAC in patients with CKD has not been defined with any certainty, particularly in those with severely impaired renal function or end stage renal disease. This has been due to the heterogeneity of studies and the relative paucity of data. This document reports the position of three Italian scientific societies engaged in the management of patients with atrial fibrillation who are treated with DOAC and present with CKD.

Effects of Anti-vitamin k oral anticoagulants on bone and cardiovascular health

Vitamin K antagonist oral anticoagulants (VKAs) have been proven over 50 years to be highly effective and acceptably safe in many settings and are still used by millions of people worldwide. The main concern about the safety of VKAs regards the risk of bleeding, but there is accumulation evidence of their potentially negative effects beyond hemostasis. Indeed, VKAs impair the action of several Vitamin-K Dependent Proteins (VKDP), such as Bone Gla protein, Matrix Gla protein, Gas6 Protein, Periostin and Gla-Ric Protein, involved in bone and vascular metabolism, thus exerting a detrimental effect on bone and vascular health. Indeed, although the evidence regarding this issue is not compelling, it has been shown that VKAs use decreases bone mass density, increases the risk of bone fractures and accelerates the process of vascular and valvular calcification. Vascular calcification is a major concern in Chronic Kidney Disease (CKD) patients, also in absence of VKAs, because of mineral metabolism derangement, chronic inflammation and oxidative stress. Direct Oral AntiCoagulants (DOACs) do not affect VKDP involved in vascular and valvular calcification, and do not induce calcific valve degeneration in animal models, being a possible alternative to AVK for CKD patients. However, the efficacy and safety of DOACs in this population, suggested by some recent observations, requires confirmation by dedicated, randomized study. We reviewed here the effects of VKAs in bone and vascular health as compared to DOACs, in order to provide the physicians with some data useful to wisely choose the most suitable anticoagulant for every patient.

Position paper on the safety/efficacy profile of Direct Oral Anticoagulants in patients with Chronic Kidney Disease: Consensus document of Società Italiana di Nefrologia (SIN), Federazione Centri per la diagnosi della trombosi e la Sorveglianza delle terapie Antitrombotiche (FCSA) and Società Italiana per lo Studio dell'Emostasi e della Trombosi (SISET)

Direct oral anticoagulants (DOAC) are mostly prescribed to prevent cardioembolic stroke in patients with non-valvular atrial fibrillation (AF). An increasing number of guidelines recommend DOAC in AF patients with preserved renal function for the prevention of thromboembolism and an increased use of DOAC in daily practice is recorded also in elderly patients. Aging is associated with a reduction of glomerular filtration rate and impaired renal function, regardless of the cause, increases the risk of bleeding. Multiple medication use (polypharmacy) for treating superimposed co-morbidities is common in both elderly and chronic kidney disease (CKD) patients and drug-drug interaction may cause accumulation of DOAC, thereby increasing the risk of bleeding. There is uncertainty on the safety profile of DOAC in patients with CKD, particularly in those with severely impaired renal function or end stage renal disease, due to the heterogeneity of studies and the relative paucity of data. This document reports the position of three Italian scientific societies engaged in the management of patients with atrial fibrillation who are treated with DOAC and present with CKD.

Medical management of a suspected atrial myxoma in a nonagenarian

Cardiac myxomas are the most frequently encountered tumors of the heart. However, they are unusual to be newly diagnosed in the geriatric population. Myxomas are among the great mimickers, with a myriad of clinical presentations related to heart failure, embolic events, and constitutional symptoms. We describe a rare case of a giant atrial myxoma in a nonagenarian presenting with heart failure, which was medically managed.

Apixaban for Stroke Prevention in Atrial Fibrillation: Why are Event Rates Higher in Clinical Practice than in Randomized Trials?—A Systematic Review

Background Recent reports suggest an important contribution from frequent off-label use of apixaban 2.5 mg twice daily to the higher rates of thromboembolic events observed in observational studies (OSs) relative to in randomized controlled trials (RCTs), and consequently, advocate against such use in all patients.

Objectives To examine factors contributing to the higher thromboembolic event rates, we estimated the prevalence of off-label use in contemporary practice, and compared patient characteristics and rates of stroke/systemic embolism, major bleeding, and mortality by apixaban dose and by study design in a systematic review and meta-analysis.

Results and Discussion We identified 18 OSs and 2 RCTs that included 155,228 and 11,928 patients, respectively. Patients in OSs more often received apixaban 2.5 mg twice daily (31.3% vs. 5.1%), were older (mean age 73.8 vs. 69.8 years), and had higher CHA2DS2-VASc scores (mean 3.6 vs. 2.9) versus those in RCTs. We observed a consistent pattern of higher rates of thromboembolic events, bleeding, and mortality in patients treated with 2.5 versus 5 mg twice daily apixaban in both OSs and RCTs.

Conclusion The higher risk profiles of patients in OSs versus RCTs, and higher rates of both bleeding and mortality not attributable to thromboembolism in patients treated with apixaban 2.5 versus 5 mg twice daily suggest that differences in patient characteristics are additional important contributors to the higher than expected thromboembolic event rates in clinical practice.