Warfarin and the Risk of Stroke and Bleeding in Patients With Atrial Fibrillation Receiving Dialysis: A Systematic Review and Meta-analysis

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

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

Efficacy and safety of direct oral anticoagulants in patients with atrial fibrillation combined with chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

Currently published studies have not observed consistent results on the efficacy and safety of direct oral anticoagulants (DOACs) use in patients with chronic kidney disease (CKD) combined with atrial fibrillation (AF). Therefore, this study conducted a meta-analysis of the efficacy and safety of DOACs for patients with AF complicated with CKD.

METHODS

Database literature was searched up to May 30, 2023, to include randomized controlled trials (RCT) involving patients with AF complicated with CKD DOACs and vitamin K antagonists (VKAs). Stroke, systemic embolism (SE), and all-cause mortality were used as effectiveness indicators, and major bleeding, intracranial hemorrhage (ICH), fatal bleeding, gastrointestinal bleeding (GIB), and clinically relevant non-major bleeding (CRNMB) were used as safety outcomes.

RESULTS

Nine RCT studies were included for analysis according to the inclusion criteria. Results of the efficacy analysis showed that compared with VKAs, DOACs reduced the incidence of stroke/SE (OR = 0.75, 95% CI 0.67-0.84) and all-cause deaths (OR = 0.84, 95% CI 0.75-0.93) in patients with AF who had comorbid CKD. Safety analyses showed that compared with VKAs, DOACs improved safety by reducing the risk of major bleeding (OR = 0.76, 95%CI 0.65-0.90), ICH (OR = 0.46, 95%CI 0.38-0.56), and fatal bleeding (OR = 0.75, 95%CI 0.65-0.87), but did not reduce the incidence of GIB and CRNMB.

CONCLUSION

Compared with VKAs, DOACs may increase efficacy and improve safety in AF patients with CKD (90 ml/min> Crcl≥15 ml/min), and shows at least similar efficacy and safety in AF patients with Kidney failure (Crcl<15 ml/min).

Anticoagulation for Patients With Concomitant Atrial Fibrillation and End-Stage Renal Disease: A Systematic Review and Network Meta-Analysis

BACKGROUND

Concomitant atrial fibrillation and end-stage renal disease is common and associated with an unfavorable prognosis. Although oral anticoagulants have been well established to prevent thromboembolism, the applicability in patients under long-term dialysis remains debatable. The study aimed to determine the efficacy and safety of anticoagulation in the dialysis-dependent population.

METHODS AND RESULTS

An updated network meta-analysis based on MEDLINE, EMBASE, and the Cochrane Library was performed. Studies published up to December 2022 were included. Direct oral anticoagulants (DOACs, dabigatran, rivaroxaban, apixaban 2.5/5 mg twice daily), vitamin K antagonists (VKAs), and no anticoagulation were compared on safety and efficacy outcomes. The outcomes of interest were major bleeding, thromboembolism, and all-cause death. A total of 42 studies, including 3 randomized controlled trials, with 185 864 subjects were pooled. VKAs were associated with a significantly higher risk of major bleeding than either no anticoagulation (hazard ratio [HR], 1.47; 95% CI, 1.34-1.61) or DOACs (DOACs versus VKAs; HR, 0.74 [95% CI, 0.64-0.84]). For the prevention of thromboembolism, the efficacies of VKAs, DOACs, and no anticoagulation were equivalent. Nevertheless, dabigatran and rivaroxaban were associated with fewer embolic events. There were no differences in all-cause death with the administration of VKAs, DOACs, or no anticoagulation.

CONCLUSIONS

For dialysis-dependent populations, dabigatran and rivaroxaban were associated with better efficacy, while dabigatran and apixaban demonstrated better safety. No anticoagulation was a noninferior alterative, and VKAs were associated with the worst outcomes.

Comparison of Effectiveness and Safety of Direct-Acting Oral Anticoagulants and Vitamin K Agonists in Patients With Atrial Fibrillation and End-Stage Kidney Disease: A Systematic Review and Meta-Analysis

The objective of the study is mentioned, but it could be further clarified by explicitly stating the aim to compare the effectiveness and safety of direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) specifically in patients with atrial fibrillation (AF) and end-stage renal disease (ESRD). We conducted a thorough electronic search of the literature, encompassing databases such as PubMed, EMBASE, Cochrane Library, and Web of Science from their inception up to March 5, 2024. Furthermore, we meticulously examined the bibliographies of included studies to identify additional relevant literature. The reporting of this meta-analysis adhered to the guidelines outlined in the Preferred Reporting of Systematic Review and Meta-analysis guidelines. The endpoints evaluated in this meta-analysis included all-cause mortality, stroke or systemic embolism, and major bleeding. Data analysis was carried out utilizing RevMan Version 5.4 (Cochrane, London, United Kingdom). Dichotomous outcomes, including all-cause mortality, stroke or systemic embolism, and major bleeding, were presented as risk ratios (RRs) with corresponding 95% confidence intervals (CI). A total of 11 studies were incorporated in this meta-analysis, comprising a pooled sample size of 44,863 participants with AF. The pooled analysis revealed no significant disparity between DOACs and VKAs concerning stroke or systemic embolism (RR: 0.93, 95% CI: 0.77 to 1.14) and all-cause mortality (RR: 0.86, 95% CI: 0.74 to 1.00). However, there was a noteworthy reduction in the risk of major bleeding events associated with DOACs compared to VKAs (RR: 0.84, 95% CI: 0.73 to 0.96). Consequently, DOACs may be considered a viable alternative to warfarin in patients with ESRD. However, we need further larger clinical trials to validate these findings.

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.

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.

Effect of Statins on All-Cause Mortality in Adults: A Systematic Review and Meta-Analysis of Propensity Score-Matched Studies

Statins are lipid-lowering medications used for the prevention of cardiovascular disease (CVD), but the pleiotropic effects of statins might be beneficial in other chronic diseases. This meta-analysis investigated the association between statin use and mortality in different chronic conditions. Eligible studies were real-world studies that compared all-cause mortality over at least 12 months between propensity score-matched statin users and non-users. Overall, 54 studies were included: 21 in CVD, 6 in chronic kidney disease, 6 in chronic inflammatory diseases, 3 in cancer, and 18 in other diseases. The risk of all-cause mortality was significantly reduced in statin users (hazard ratio: 0.72, 95% confidence interval: 0.66−0.76). The reduction in mortality risk was similar in CVD studies (0.73, 0.66−0.76) and non-CVD studies (0.70, 0.67−0.79). There were no significant differences in the risk reduction between cohorts with different diseases (p = 0.179). The greatest mortality reduction was seen in studies from Asia (0.61, 0.61−0.73) and the lowest in studies from North America (0.78, 0.73−0.83) and Australia (0.78, 0.62−0.97). There was a significant heterogeneity (I2 = 95%, tau2 = 0.029, p < 0.01). In conclusion, statin use was associated with a significantly reduced risk of all-cause mortality in real-world cohorts with CVD and non-CVD.

Direct Oral Anticoagulants vs. Warfarin in Hemodialysis Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis

Background

The use of Direct Oral Anticoagulants (DOACs) in patients who have both atrial fibrillation (AF) and end-stage renal disease (ESRD) requiring hemodialysis remains controversial, with warfarin remaining the mainstay of the treatment. As hemodialysis patients were excluded from most clinical DOACs trials, the evidence of their efficacy and safety is lacking in this cohort of patients.

Aim

To review the current evidence investigating safety profile and the efficacy of DOACs in comparison with warfarin in patients with AF and end-stage renal disease (ESRD) requiring hemodialysis.

Methods and Results

We included five studies with a total of 34,516 patients in our meta-analysis. The outcomes were major bleeding, ischemic stroke, systemic embolization, hemorrhagic stroke, gastrointestinal bleeding, minor bleeding, and death. Of these patients, 31,472 (92.14%) received warfarin and 3,044 patients received DOACs (8.91%). No significant differences in the incidence of hemorrhagic stroke, major bleeding, hemodialysis access site bleeding, ischemic stroke, and GI bleeding were found between DOACs and warfarin. However, there were higher rates of systemic embolization, minor bleeding, and death events in patients who received DOACs than in the warfarin group (3.39% vs. 1.97%, P-value = 0.02), (6.78% vs. 2.2%, P-value 0.02), and (11.38% vs. 5.12%, P-value < 0.006) respectively.

Conclusion

In patients on dialysis who require anticoagulation for AF, warfarin could be associated with a significant reduction in minor bleeding, systemic embolization, and death compared to DOACs. These findings need to be validated by further prospective studies to address the best strategy to deal with the increased thrombotic and bleeding risks in such patients.

Epidemiology of cardiovascular death in kidney failure: An Australian and New Zealand cohort study using data linkage

Aim

Cardiovascular mortality risk evolves over the lifespan of kidney failure (KF), as patients develop comorbid disease and transition between treatment modalities. Absolute cardiovascular death rates would help inform clinical practice and health‐care provision, but are not well understood across a continuum of dialysis and transplant states. We aimed to characterize cardiovascular death across the natural history of KF using a lifespan approach.

Methods

We performed a population‐based cohort study of incident patients commencing kidney replacement therapy in Australia and New Zealand. Cardiovascular deaths were identified using data linkage to national death registers. We estimated the probability of death and kidney transplant using multi‐state models, and calculated rates of graft failure and cardiovascular death across demographic factors and comorbidities.

Results

Among 60 823 incident patients followed over 381 874 person‐years, 25% (8492) of deaths were from cardiovascular disease. At 15 years from treatment initiation, patients had a 15.2% probability of cardiovascular death without being transplanted, but only 2.3% probability of cardiovascular death post‐transplant. Females had a 3% lower probability of cardiovascular death at 15 years (15.3% vs. 18.6%) but 4% higher probability of non‐cardiovascular death (54.5% vs. 50.8%). Within the first year of dialysis, cardiovascular mortality peaked in the second month and showed little improvement across treatment era.

Conclusion

Despite improvements over time, cardiovascular death remains common in KF, particularly among the dialysis population and in the first few months of treatment. Multi‐state models can provide absolute measures of cardiovascular mortality across both dialysis and transplant states.

In this population‐based cohort study using multi‐state models (alive without kidney transplant [KT], CV death without KT, non‐CV death without KT, alive after first KT, CV death after first KT and non‐CV death after first KT), the probability of CV death was higher in non‐KT than KT patients at 15 years from treatment. In patients on dialysis, CV mortality was highest from the second month after commencing dialysis and remained high thereafter. Thus, the use of multi‐state models provides helpful information on impacts of different treatments with respect to serious outcomes.

Individual Variability in von Willebrand Factor Fragility in Response to Shear Stress: A Possible Clue for Predicting Bleeding Risk

Acquired von Willebrand syndrome (AVWS), characterized by reduced von Willebrand factor (VWF) large multimers, has recently been implicated as the principal mechanism underlying bleeding in patients implanted with left ventricular assist devices (LVADs). Hematological severity of AVWS varies among patients, even if an identical device is implanted. We investigated whether this diversity in hematological severity is due to individual variability in VWF fragility, according to responses to incremental shear stress. Whole-blood samples were sheared at 20,000-40,000 s-1 shear rate, an index of shear stress, using a custom-made shear stressor that could generate shear stress compatible with that produced by an LVAD. The degree of VWF large multimers degradation was evaluated using the VWF large multimer index. A significant inverse correlation was observed between the VWF large multimer index and LVAD-compatible magnitudes of shear stress: the VWF large multimer indices were 68.5 ± 18.3, 48.0 ± 13.9, 33.9 ± 12.1, 23.7 ± 7.9, and 18.7% ± 8.7% at 20,000, 25,000, 30,000, 35,000, and 40,000 s-1 of shear rates, respectively (P < 0.0001). Furthermore, experimental VWF large multimer index values were compatible with those derived from patients with implanted LVADs (median; 28.9%). Finally, reduction in the VWF large multimer index corresponding to shear stress showed individual variation. We demonstrated that the combined use of a novel high shear stress loading device and quantitative evaluation of VWF large multimers may predict risk of bleeding before LVAD implantation.

Atrial fibrillation, end-stage renal disease and hemorrhagic pleural-pericarditis

Pericarditis is the most common pericardial disease found in clinical practice, with an incidence of acute pericarditis reported in 27.7 cases per 100,000 subjects per year. Hemodialysis in end stage renal disease (ESRD) is associated with frequent cardiovascular modifications, mostly because of the highly fluctuating levels of potassium, magnesium, ionized calcium, sodium and volume status. The risk of arrhythmias is increased and chronic atrial fibrillation (AF) can be found among approximately 14% of patients. The renal disease combined with arrhythmias increases the risk of systemic thromboembolism but also of bleeding events. Here we present the case of a male patient, with ESRD, recently diagnosed with intradialytic paroxysmal AF for which oral anticoagulation therapy is initiated, but it’s early complicated with hemorrhagic pleural-pericarditis.

Time in Therapeutic Range Using a Nomogram for Dose Adjustment of Warfarin in Patients on Hemodialysis With Atrial Fibrillation

Background:

Patients treated with hemodialysis and prescribed warfarin typically have lower time in therapeutic range (TTR) compared to the general population. This may result in less benefit or increased risk of over anticoagulation in these patients.

Objective:

To assess effectiveness of use of an electronic nomogram for the management of warfarin therapy in patients treated with hemodialysis.

Design:

Retrospective chart review.

Setting:

Adult patients treated with hemodialysis.

Patients:

Patients on hemodialysis receiving warfarin for the management of atrial fibrillation (AF) with therapy managed by nursing led electronic nomogram.

Measurements:

Time in therapeutic range (as fraction and Rosendaal).

Methods:

Retrospective chart review over 1 year of international normalized ratio (INR) results was completed, and TTR was calculated. Comparison of patients with TTR greater than 60% to those less than 60% was completed using chi-square analysis.

Results:

Of 43 patients with warfarin therapy managed by the nomogram, the mean TTR was 55.2% (calculated by fraction method) or 61.2% (calculated by Rosendaal method). More than half of the patients (63.5%) had moderate to good control, defined as TTR greater than 60%. Female sex, liver disease, or history of substance use and more medication holds were associated with lower TTR.

Limitations:

Small sample size and retrospective nature of review.

Conclusions:

The results of this review supports the use of an electronic, nursing-led nomogram for the maintenance management of warfarin therapy in stable patients treated with hemodialysis, as use results in TTR greater than 60% for more than half of patients.

A Review of Direct Oral Anticoagulants in Patients With Stage 5 or End-Stage Kidney Disease

OBJECTIVE

To evaluate the role of oral anticoagulation in patients with stage 5 chronic kidney disease (CKD-5) or end-stage kidney disease (ESKD).

DATA SOURCES

A literature search of PubMed (January 2000 to July 1, 2021), the Cochrane Library, and Google Scholar databases (through April 1, 2021) was performed with keywords DOAC (direct-acting oral anticoagulant) OR NOAC or dabigatran OR rivaroxaban OR apixaban OR edoxaban AND end-stage kidney disease combined with atrial fibrillation (AF) or venous thromboembolism (VTE) OR pulmonary embolism OR deep-vein thrombosis.

STUDY SELECTION AND DATA EXTRACTION

Case-control, cohort, and randomized controlled trials comparing DOACs to an active control for AF or VTE in patients with CKD-5 or ESKD and reporting outcomes of stroke, recurrent thromboembolism, or major bleeding were included.

DATA SYNTHESIS

Nine studies were included. Efficacy data supporting routine use of warfarin or DOACs in CKD-5 or ESKD are limited. Rivaroxaban and apixaban may provide enhanced safety compared to warfarin in patients with AF. Data for VTE are limited to 1 retrospective study.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Because of the paucity of rigorous, prospective studies in CKD-5 or ESKD, OACs should not be broadly used in this population. It is clear that data regarding efficacy of DOACs cannot be reliably and safely extrapolated from the non-ESKD population. Therefore, use of OACs in this population should be individualized.

CONCLUSIONS

If OACs for stroke prevention with AF are deemed necessary, apixaban or rivaroxaban can be considered. DOACs cannot currently be recommended over warfarin in patients with CKD-5 or ESKD and VTE.

Chronic Kidney Disease and Cerebrovascular Disease: Consensus and Guidance From a KDIGO Controversies Conference

The global health burden of chronic kidney disease is rapidly rising, and chronic kidney disease is an important risk factor for cerebrovascular disease. Proposed underlying mechanisms for this relationship include shared traditional risk factors such as hypertension and diabetes, uremia-related nontraditional risk factors, such as oxidative stress and abnormal calcium-phosphorus metabolism, and dialysis-specific factors such as cerebral hypoperfusion and changes in cardiac structure. Chronic kidney disease frequently complicates routine stroke risk prediction, diagnosis, management, and prevention. It is also associated with worse stroke severity, outcomes and a high burden of silent cerebrovascular disease, and vascular cognitive impairment. Here, we present a summary of the epidemiology, pathophysiology, diagnosis, and treatment of cerebrovascular disease in chronic kidney disease from the Kidney Disease: Improving Global Outcomes Controversies Conference on central and peripheral arterial disease with a focus on knowledge gaps, areas of controversy, and priorities for research.

Value of left atrial diameter with CHA2DS2-VASc score in predicting left atrial/left atrial appendage thrombosis in non-valvular atrial fibrillation

Fundamentos

A fibrilação atrial é a arritmia persistente mais comum e é o principal fator que leva ao tromboembolismo.

Objetivo

Investigar o valor do diâmetro do átrio esquerdo combinado com o escore CHA2DS2-VASc na predição da trombose atrial esquerda/trombose de apêndice atrial esquerdo na fibrilação atrial não valvar.

Métodos

Trata-se de estudo retrospectivo. 238 pacientes com fibrilação atrial não valvar foram selecionados e divididos em dois grupos: trombose e não trombose. Determinou-se o escore CHA2DS2-VASc. Valores de p<0,05 foram considerados estatisticamente significativos.

Resultados

A análise de regressão logística multivariada revelou que histórico de acidente vascular cerebral/ataque isquêmico transitório, doença vascular, escore CHA2DS2-VASc, DAE, DDFVE e FEVE foram fatores de risco independentes para trombose atrial esquerda/trombose de apêndice atrial esquerdo (p<0,05). A análise da curva ROC ( Receiver Operating Characteristic ) revelou que a área sob a curva para o escore CHA2DS2-VASc na predição de trombose atrial esquerda/trombose de apêndice atrial esquerdo foi de 0,593 quando o escore CHA2DS2-VASc foi ≥3 pontos, e a sensibilidade e especificidade foram 86,5% e 32,6%, respectivamente, enquanto a área sob a curva para o DAE na predição de trombose atrial esquerda/trombose de apêndice atrial esquerdo foi 0,786 quando o DAE foi ≥44,17 mm, e a sensibilidade e especificidade foram 89,6% e 60,9%, respectivamente. Entre os diferentes grupos CHA2DS2-VASc, a taxa de incidência de trombose atrial esquerda/trombose de apêndice atrial esquerdo em pacientes com DAE ≥44,17 mm foi maior do que em pacientes com DAE <44,17 mm (p <0,05).

Conclusão

O escore CHA2DS2-VASc e o DAE estão correlacionados com a trombose atrial esquerda/trombose de apêndice atrial esquerdo na fibrilação atrial não valvar. Para pacientes com escore CHA2DS2-VASc de 0 ou 1, quando o DAE é ≥44,17 mm, o risco de trombose atrial esquerda/trombose de apêndice atrial esquerdo permaneceu alto. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)

Clinical Evidence for the Choice of the Direct Oral Anticoagulant in Patients with Atrial Fibrillation According to Creatinine Clearance

Atrial fibrillation (AF) often coexists with chronic kidney disease (CKD), which confer to the patient a higher risk of both thromboembolic and hemorrhagic events. Oral anticoagulation therapy, nowadays preferably with direct oral anticoagulants (DOACs), represents the cornerstone for ischemic stroke prevention in high-risk patients. However, all four available DOACs (dabigatran, apixaban, rivaroxaban and edoxaban) are eliminated by the kidneys to some extent. Reduced kidney function facilitates DOACs accumulation and, therefore, different dose reductions are required, with slight differences between American and European recommendations especially in case of severe renal impairment (creatinine clearance < 30 mL/min). Overall, the use of DOACs in patients with non-end stage CKD and AF is effective similarly to warfarin, showing a better safety profile. The management of thromboembolic risk among patients with AF on dialysis remains challenging, as warfarin effectiveness for stroke prevention in this population is questionable and retrospective data on apixaban need to be confirmed on a larger scale. In kidney transplant recipients, DOACs may provide a potentially safer option compared to warfarin, but co-administration with immunosuppressants is a matter of concern.

Anticoagulation in Patients with End-Stage Renal Disease and Atrial Fibrillation: Confusion, Concerns and Consequences

End-stage renal disease (ESRD) patients have a higher prevalence of diabetes mellitus, hypertension, congestive heart failure and advanced age, along with an increased incidence of non-valvular atrial fibrillation (AF), thereby increasing the risk for cerebrovascular accidents. Systemic anticoagulation is therefore recommended in patients with ESRD with AF to reduce the risk and complications from thromboembolism. Paradoxically, these patients are at an increased risk of bleeding due to great degree of platelet dysfunction and impaired interaction between platelet and endothelium. Currently, CHA2DS2-VASc and Hypertension, Abnormal liver/kidney function, Stroke, Bleeding, Labile INR, Elderly, Drugs or alcohol (HAS-BLED) are the recommended models for stroke risk stratification and bleeding risk assessment in patients with AF. There is conflicting data regarding benefits and risks of medications such as antiplatelet agents, warfarin and direct oral anticoagulants in ESRD patients with AF. Moreover, there is no randomized controlled trial data to guide the clinical decision making. Hence, a multi-disciplinary approach with annual re-evaluation of treatment goals and risk-benefit assessment has been recommended. In this article, we review the current recommendations with risks and benefits of anticoagulation in patients with ESRD with AF.

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

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

Association Between Use of Warfarin for Atrial Fibrillation and Outcomes Among Patients With End-Stage Renal Disease: A Systematic Review and Meta-analysis

IMPORTANCE

Several studies have examined the role of warfarin in preventing strokes in patients with atrial fibrillation and end-stage renal disease; however, the results remain inconclusive.

OBJECTIVE

To assess recently published studies to examine the outcomes of the use of warfarin among patients with atrial fibrillation and end-stage renal disease.

DATA SOURCES

A literature search was performed using the terms warfarin and atrial fibrillation and end-stage renal disease and warfarin and atrial fibrillation and dialysis in the MEDLINE, Embase, and Google Scholar databases from January 1, 2008, to February 28, 2019.

STUDY SELECTION

The studies included were those with patients with end-stage renal disease and atrial fibrillation who were receiving warfarin and with hazard ratios (HRs) of at least 1 primary outcome. The studies excluded were those with a lack of information on outcomes and unreliable 95% CIs of the results.

DATA EXTRACTION AND SYNTHESIS

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed in selecting studies. Collected data were also scrutinized for reliable 95% CIs. Finally, studies were examined for perceived biases, their limitations, and the definitions of the outcomes.

MAIN OUTCOMES AND MEASURES

The HRs and 95% CIs were calculated for the incidence of ischemic stroke, hemorrhagic stroke, major bleeding, and mortality among patients receiving anticoagulants and those not receiving anticoagulants.

RESULTS

Study selection yielded 15 studies with a total of 47 480 patients with atrial fibrillation and end-stage renal disease. Of these patients, 10 445 (22.0%) were taking warfarin. With a mean (SD) follow-up period of 2.6 (1.4) years, warfarin use was associated with no significant change for the risk of ischemic stroke (HR, 0.96; 95% CI, 0.82-1.13), with a significantly higher risk of hemorrhagic stroke (HR, 1.49; 95% CI, 1.03-1.94), with no significant difference in the risk of major bleeding (HR, 1.20; 95% CI, 0.99-1.47), and with no change in overall mortality (HR, 0.95; 95% CI, 0.83-1.09).

CONCLUSIONS AND RELEVANCE

In the studies reviewed, warfarin use appears to have been associated with no change in the incidence of ischemic stroke in patients with atrial fibrillation and end-stage renal disease. However, from the studies reviewed, it does appear to be associated with a significantly higher risk of hemorrhagic stroke, with no significant difference in the risk of major bleeding, and with no change in mortality.

Triple therapy in patients with atrial fibrillation and acute coronary syndrome or percutaneous coronary intervention/stenting

Patients with atrial fibrillation (AF) and acute coronary syndrome (ACS) are at high risk of stroke, recurrent coronary ischemic events, and cardiovascular mortality. The composition of antithrombotic therapy including an oral anticoagulant and antiplatelet drug(s) should be tailored according to the individual patient's risk profile, to reduce the bleeding risk and maintain antithrombotic effect. There is no single antithrombotic treatment regimen that would fit to all patients with AF and ACS. However, available data promote the use of full-dose direct oral anticoagulants (DOACs) (dabigatran 150 mg twice daily or apixaban 5 mg twice daily) or rivaroxaban 15 mg once daily in patients with AF and ACS or percutaneous coronary intervention (PCI). For many patients, a DOAC plus P2Y12 inhibitor early after ACS and/or PCI would be optimal, whereas a longer course of triple therapy should be used in patients at high thrombotic risk.

[Atrial Fibrillation in Patients on Dialysis Therapy: Epidemiology, Prognosis and Choice of Anticoagulant Therapy]

The review presents data on the prevalence of atrial fibrillation in patients on dialysis therapy. It is shown that dialysis-dependent patients with non-valve atrial fibrillation prognosis is extremely unfavorable, significantly increased risk of death due to both ischemic and hemorrhagic complications. Scales to assess the risk of thromboembolic and hemorrhagic complications in patients with atrial fibrillation on program dialysis are not validated. The lack of data from randomized clinical trials makes it much more difficult to choose anticoagulant therapy in patients with terminal stage of chronic kidney disease on dialysis who have undergone kidney transplantation. Therefore, the need for anticoagulant therapy and the choice of drugs in patients in this category should be made on the basis of a personalized multidisciplinary approach, taking into account comorbid pathology and the patient's preferences.

Prevalence of and risk factors for postoperative hemorrhage after lower third molar extraction on warfarin therapy: a multicenter retrospective study in Japan

Postoperative hemorrhage after tooth extraction is a critical and clinically important issue for clinicians and patients receiving anticoagulants. The purpose of the present study was to investigate the prevalence of and risk factors for postoperative hemorrhage after lower third molar extraction in Japanese patients receiving warfarin therapy. A total of 142 patients who underwent lower third molar extraction between January 2010 and December 2016 were included, and their medical records were retrospectively reviewed. The prevalence of and risk factors for postoperative hemorrhage were investigated. The prevalence of postoperative hemorrhage after lower third molar extraction was significantly higher in patients receiving warfarin than in healthy subjects (21.8% vs 0.7%, P < 0.001). The cutoff value for PT-INR was 2.11 based on a receiver-operating characteristic analysis. A multivariate analysis indicated that an elevated PT-INR value [hazard ratio (HR) 3.798, 95% confidence interval (CI) 1.400-10.467, P < 0.01], preoperative antibiotic administration (HR 4.434, 95% CI 1.591-14.775, P < 0.01), difficulties with intraoperative hemostasis (HR 16.298, 95% CI 2.986-110.677, P < 0.01), and higher serum creatinine levels (HR 7.465, 95% CI 1.616-39.576, P < 0.05) are significant predictors of postoperative hemorrhage after lower third molar extraction. Multivariate correlations were observed between risk factors including an elevated PT-INR value, preoperative antibiotic administration, and higher serum creatinine levels, and postoperative hemorrhage after lower third molar extraction in patients receiving warfarin therapy. Clinicians need to consider these risk factors for postoperative hemorrhage after the lower third molar extraction and monitor PT-INR in patients receiving warfarin therapy.

Quality Improvement Program Improves Time in Therapeutic Range for Hemodialysis Recipients Taking Warfarin

Introduction

Studies have shown that achieving a time in therapeutic range (TTR) for warfarin of greater than 60% is associated with a lower risk of bleeding. However, many patients on hemodialysis (HD) do not achieve this target.

Methods

We audited TTR achievement at the in-center HD unit of our hospital in 2017 and found that only 40% of patients had achieved a TTR >60%. We aimed to improve the percentage of HD patients achieving target TTR within 2 years. We reported each patient's individualized trend in quarterly TTR to their primary warfarin prescriber as an audit-feedback report. These reports were generated, disseminated, and subsequently improved following a series of plan-do-study-act cycles. We then used statistical process control to assess for changes in the percentage of HD patients achieving target TTR over time.

Results

In the primary analysis, 28 patients were included in the baseline period, and 46 were included in the intervention period. At baseline, the percentage of patients achieving a TTR >60% varied between 33% and 45% (mean ± SD, 40% ± 5%); post-intervention, this metric improved and varied between 52% and 71% (mean ± SD, 61% ± 8%). In time-series analysis, there was evidence of statistically significant variation between the 2 periods and evidence of sustained improvement.

Conclusions

A quality improvement program consisting of an audit-feedback report that raises awareness of the quality gap in TTR achievement can result in substantial improvement in the safe and efficacious administration of warfarin to patients receiving maintenance hemodialysis.

Prevention and treatment of stroke in patients with chronic kidney disease: an overview of evidence and current guidelines

Chronic kidney disease is strongly associated with an increased risk of stroke, small vessel disease, and vascular dementia. Common vascular factors for stroke, such as hypertension, diabetes, and atrial fibrillation, are more prevalent in patients with chronic kidney disease, accounting for this association. However, factors unique to these patients, such as uremia, oxidative stress, and mineral and bone abnormalities, as well as dialysis-related factors are also believed to contribute to risk. Despite improvements in stroke treatment and survival in the general population, the rate of improvement in patients with chronic kidney disease, especially those who are dialysis dependent, has lagged behind. There is a lack of or conflicting evidence that those with renal disease, particularly when advanced or older, consistently derive benefit from currently available preventive and therapeutic interventions for stroke in the general population. In this review, we explore the complexities and challenges of these interventions in the population with renal disease.

Atrial fibrillation in patients with end-stage renal disease on hemodialysis: Magnitude of the problem and new approach to oral anticoagulation

Atrial fibrillation (AF) is a frequent comorbid condition in patients with end-stage renal disease on hemodialysis (HD) with a prevalence of up to 27%. The incidence rate of stroke in AF patients on HD is approximately 5%. The AF-associated risk of stroke is a major clinical challenge because current evidence for anticoagulation in HD patients with AF is based on observational data. Results from these observational studies is largely contradictory because they do not show a clear benefit of vitamin K antagonists over no treatment in terms of stroke prevention, and they show an increased risk of hemorrhage associated with anticoagulation treatment in HD patients. HD patients were not included in randomized trials of the direct oral anticoagulants (DOACs), and therefore there is no evidence to support efficacy and safety of DOACs compared to vitamin K antagonists in HD patients. The pharmacological characteristics of DOACs are of particular interest in the HD setting. The factor Xa inhibitors rivaroxaban, apixaban, and edoxaban are not predominantly eliminated via the kidneys. The thrombin inhibitor dabigatran is 80% eliminated via the kidneys but is dialyzable due to its low protein binding. In this narrative review, we examine the current state of evidence regarding the prevalence of AF in patients on HD, the associated risk of stroke, and the efficacy and safety of anticoagulation for stroke prevention in the HD setting. Further, based on the pharmacokinetic properties of DOACs, we discuss their potential use in patients on HD and ongoing randomized trials.

The Association of Atrial Fibrillation and Ischemic Stroke in Patients on Hemodialysis: A Competing Risk Analysis

Background

Stroke is common in patients with end-stage renal disease (ESRD) treated with hemodialysis (HD) and associated with high mortality rate. In the general population, atrial fibrillation (AF) is a major risk factor for stroke and therapeutic anticoagulation is associated with risk reduction, whereas in ESRD the relationship is less clear.

Objective

The purpose of this study is to demonstrate the influence of AF on stroke rates and probability in those on HD following competing risk analyses.

Design

A national record linkage cohort study.

Setting

All renal and stroke units in Scotland, UK.

Patients

All patients with ESRD receiving HD within Scotland from 2005 to 2013 (follow-up to 2015).

Measurements

Demographic, clinical, and laboratory data were linked between the Scottish Renal Registry, Scottish Stroke Care Audit, and hospital discharge data. Stroke was defined as a fatal or nonfatal event and mortality derived from national records.

Methods

Associations for stroke were determined using competing risk models: the cause-specific hazards model and the Fine and Gray subdistribution hazards model accounting for the competing risk of death in models of all stroke, ischemic stroke, and first-ever stroke.

Results

Of 5502 patients treated with HD with 12 348.6-year follow-up, 363 (6.6%) experienced stroke. The stroke incidence rate was 26.7 per 1000 patient-years. Multivariable regression on the cause-specific hazard for stroke demonstrated age, hazard ratio (HR) (95% confidence interval [CI]) = 1.04 (1.03-1.05); AF, HR (95% CI) = 1.88 (1.25-2.83); prior stroke, HR (95% CI) = 2.29 (1.48-3.54), and diabetes, HR (95% CI) = 1.92 (1.45-2.53); serum phosphate, HR (95% CI) = 2.15 (1.56-2.99); lower body weight, HR (95% CI) = 0.99 (0.98-1.00); lower hemoglobin, HR (95% CI) = 0.88 (0.77-0.99); and systolic blood pressure (BP), HR (95% CI) = 1.01 (1.00-1.02), to be associated with an increased stroke rate. In contrast, the subdistribution HRs obtained following Fine and Gray regression demonstrated that AF, weight, and hemoglobin were not associated with stroke risk. In both models, AF was significantly associated with nonstroke death.

Limitations

Our analyses derive from retrospective data sets and thus can only describe association not causation. Data on anticoagulant use are not available.

Conclusions

The incidence of stroke in HD patients is high. The competing risk of "prestroke" mortality affects the relationship between AF and risk of future stroke. Trial designs for interventions to reduce stroke risk in HD patients, such as anticoagulation for AF, should take account of competing risks affecting associations between risk factors and outcomes.

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

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

Oral Anticoagulants in Patients With Atrial Fibrillation and End-Stage Renal Disease

The role of oral anticoagulants (OAC) in atrial fibrillation (AF) is well established. However, none of the randomized controlled trials included patients with end-stage renal disease (ESRD) leaving a lack of evidence in this large, challenging and unique patient group. Patients on hemodialysis (HD) with AF have additional risk factors for stroke due to vascular comorbidities, HD treatment, age, and diabetes. Conversely, they are also at increased risk of major bleeding due to uremic platelet impairment. Anticoagulants increase bleeding risk in patients with ESRD and HD up to 10-fold compared with non chronic kidney disease (CKD) patients on warfarin. There are conflicting data and recommendations regarding use of OACs in ESRD which will be reviewed in this article. We conclude by proposing a modified strategy for OAC use in ESRD based on the latest evidence.

Warfarin Dosing and Outcomes in Chronic Kidney Disease: A Closer Look at Warfarin Disposition

BACKGROUND

Chronic Kidney Disease (CKD) is a prevalent worldwide health problem. Patients with CKD are more prone to developing cardiovascular complications such as atrial fibrillation and stroke. This warrants the use of oral anticoagulants, such as warfarin, in this population. While the efficacy and safety of warfarin in this setting remain controversial, a growing body of evidence emphasizes that warfarin use in CKD can be problematic. This review discusses 1) warfarin use, dosing and outcomes in CKD patients; and 2) possible pharmacokinetic mechanisms for altered warfarin dosing and response in CKD.

METHODS

Structured search and review of literature articles evaluating warfarin dosing and outcomes in CKD. Data and information about warfarin metabolism, transport, and pharmacokinetics in CKD were also analyzed and summarized.

RESULTS

The literature data suggest that changes in warfarin pharmacokinetics such as protein binding, nonrenal clearance, the disposition of warfarin metabolites may partially contribute to altered warfarin dosing and response in CKD.

CONCLUSION

Although the evidence to support warfarin use in advanced CKD is still unclear, this synthesis of previous findings may help in improving optimized warfarin therapy in CKD settings.

Oral Anticoagulation in Patients With End-Stage Kidney Disease on Dialysis and Atrial Fibrillation

Patients with end-stage kidney disease (ESKD) have an elevated incidence of atrial fibrillation (AF) and are at increased risk for thromboembolic events. However, these patients are also at increased risk for bleeding and it is unclear whether they benefit from an oral anticoagulant. Point prevalent on July 1, 2015, only ~28% of dialysis patients with AF were on oral anticoagulation. Warfarin was the most commonly used oral anticoagulant, followed by apixaban, while dabigatran and rivaroxaban were rarely used. This article reviews the current evidence regarding each oral anticoagulant especially as they relate to patients with ESKD.

Anticoagulation in atrial fibrillation with heart failure

Heart failure (HF) and atrial fibrillation (AF) frequently coexist, and they can beget one another due to similar factors and shared pathophysiology. These pathophysiologic changes promote the episodes of AF, while they in turn predispose to the exacerbation of HF. In this review, we will discuss pathophysiological mechanisms shared by AF and HF. Patients with concomitant HF and AF are at a particularly high risk of thromboembolism, which contribute to even worse symptoms and poorer prognosis. Vitamin K antagonists (VKA) (warfarin) were the traditional medication in AF patients for the prevention of stroke, whereas the advance of novel non-VKA oral anticoagulants (NOACs) (dabigatran, apixaban, rivaroxaban, and edoxaban) is challenging these standard prescriptions. NOACs' potential advantages over warfarin, including fixed dosing regimens, wide therapeutic window, and more sustained anticoagulant response, promote clinicians to consider these novel agents in the first place. However, some data suggested patients with AF and HF may receive different therapeutic response than those with AF alone in anticoagulant treatment. Accordingly, we aim to assess the potential role of oral anticoagulants, especially NOACs, in the management of patients with concomitant AF and HF.

Demystifying the Benefits and Harms of Anticoagulation for Atrial Fibrillation in Chronic Kidney Disease

Patients with CKD represent a vulnerable population where the risks of atrial fibrillation, ischemic stroke, and bleeding are all heightened. Although large randomized, controlled trials in the general population clearly demonstrate that the benefits of warfarin and direct-acting oral anticoagulants outweigh the risks of bleeding, no such studies have been conducted in patients when their creatinine clearance falls below 25-30 ml/min. Without randomized, controlled trial data, the role of anticoagulation in patients with CKD with atrial fibrillation remains unclear and our practice is informed by a growing body of imperfect literature such as observational and pharmacokinetic studies. This article aims to present a contemporary literature review of the benefits versus harms of anticoagulation in atrial fibrillation for patients with CKD stages 3, 4, 5, and 5 on dialysis. Although unanswered questions and areas of clinical equipoise remain, this piece serves to assist physicians in interpreting the complex body of literature and applying it to their clinical care.

Cost-Utility Analysis of Apixaban versus Warfarin in Atrial Fibrillation Patients with Chronic Kidney Disease

BACKGROUND

Warfarin use for stroke prevention in atrial fibrillation (AF) patients with chronic kidney disease is debated. Apixaban was shown to be safer than warfarin, with superior reduction in the risk of stroke, systemic embolism, mortality, and major bleeding irrespective of kidney function.

OBJECTIVES

To evaluate the cost-utility of apixaban compared with warfarin in AF patients at different levels of kidney function.

METHODS

A Markov model was used to estimate the cost effectiveness of apixaban compared with warfarin in AF patients at three levels of kidney function: estimated glomerular filtration rate (eGFR) of more than 80 ml/min, 50 to 80 ml/min, and 50 ml/min or less. Event rates and associated utilities were obtained from previous literature. The model adopted the US health care system perspective, with hospitalization costs extracted from the Healthcare and Utilization Project. Treatment costs were obtained from official price lists. Univariate and probabilistic sensitivity analyses were performed to evaluate the robustness of results.

RESULTS

Apixaban was a dominant treatment strategy compared with warfarin in AF patients with eGFR levels of 50 ml/min or less and 50 to 80 ml/min. In patients with an eGFR of more than 80 ml/min, apixaban was cost-effective compared with warfarin, costing $6307 per quality-adjusted life-year gained. Results were consistent assuming anticoagulant discontinuation after major bleeding events. Compared with dabigatran and rivaroxaban, apixaban was the only cost-effective anticoagulant strategy relative to warfarin in both mild and moderate renal impairment settings.

CONCLUSIONS

Apixaban is a favorably cost-effective alternative to warfarin in AF patients with normal kidney function and potentially cost-saving in those with renal impairment.

Prescribing Hemodialysis or Hemodiafiltration: When One Size Does Not Fit All the Proposal of a Personalized Approach Based on Comorbidity and Nutritional Status

There is no simple way to prescribe hemodialysis. Changes in the dialysis population, improvements in dialysis techniques, and different attitudes towards the initiation of dialysis have influenced treatment goals and, consequently, dialysis prescription. However, in clinical practice prescription of dialysis still often follows a "one size fits all" rule, and there is no agreed distinction between treatment goals for the younger, lower-risk population, and for older, high comorbidity patients. In the younger dialysis population, efficiency is our main goal, as assessed by the demonstrated close relationship between depuration (tested by kinetic adequacy) and survival. In the ageing dialysis population, tolerance is probably a better objective: "good dialysis" should allow the patient to attain a stable metabolic balance with minimal dialysis-related morbidity. We would like therefore to open the discussion on a personalized approach to dialysis prescription, focused on efficiency in younger patients and on tolerance in older ones, based on life expectancy, comorbidity, residual kidney function, and nutritional status, with particular attention placed on elderly, high-comorbidity populations, such as the ones presently treated in most European centers. Prescription of dialysis includes reaching decisions on the following elements: dialysis modality (hemodialysis (HD) or hemodiafiltration (HDF)); type of membrane (permeability, surface); and the frequency and duration of sessions. Blood and dialysate flow, anticoagulation, and reinfusion (in HDF) are also briefly discussed. The approach described in this concept paper was developed considering the following items: nutritional markers and integrated scores (albumin, pre-albumin, cholesterol; body size, Body Mass Index (BMI), Malnutrition Inflammation Score (MIS), and Subjective Global Assessment (SGA)); life expectancy (age, comorbidity (Charlson Index), and dialysis vintage); kinetic goals (Kt/V, normalized protein catabolic rate (n-PCR), calcium phosphate, parathyroid hormone (PTH), beta-2 microglobulin); technical aspects including vascular access (fistula versus catheter, degree of functionality); residual kidney function and weight gain; and dialysis tolerance (intradialytic hypotension, post-dialysis fatigue, and subjective evaluation of the effect of dialysis on quality of life). In the era of personalized medicine, we hope the approach described in this concept paper, which requires validation but has the merit of providing innovation, may be a first step towards raising attention on this issue and will be of help in guiding dialysis choices that exploit the extraordinary potential of the present dialysis "menu".

Syncope and Collapse Are Associated with an Increased Risk of Cardiovascular Disease and Mortality in Patients Undergoing Dialysis

Objective: This study explored the impact of syncope and collapse (SC) on cardiovascular events and mortality in patients undergoing dialysis. Methods: Patients undergoing dialysis with SC (n = 3876) were selected as the study cohort and those without SC who were propensity score-matched at a 1:1 ratio were included as controls. Major adverse cardiovascular events (MACEs), including acute coronary syndrome (ACS), arrhythmia or cardiac arrest, stroke, and overall mortality, were evaluated and compared in both cohorts. Results: The mean follow-up periods until the occurrence of ACS, arrhythmia or cardiac arrest, stroke, and overall mortality in the SC cohort were 3.51 ± 2.90, 3.43 ± 2.93, 3.74 ± 2.97, and 3.76 ± 2.98 years, respectively. Compared with the patients without SC, those with SC had higher incidence rates of ACS (30.1 vs. 24.7 events/1000 people/year), arrhythmia or cardiac arrest (6.75 vs. 3.51 events/1000 people/year), and stroke (51.6 vs. 35.7 events/1000 people/year), with higher overall mortality (127.7 vs. 77.9 deaths/1000 people/year). The SC cohort also had higher risks for ACS, arrhythmia or cardiac arrest, stroke, and overall mortality (adjusted hazard ratios: 1.28 (95% confidence interval (CI) = 1.11⁻1.46), 2.05 (95% CI = 1.50⁻2.82), 1.48 (95% CI = 1.33⁻1.66), and 1.79 (95% CI = 1.67⁻1.92), respectively) than did the non-SC cohort. Conclusion: SC was significantly associated with cardiovascular events and overall mortality in the patients on dialysis. SC may serve as a prodrome for cardiovascular comorbidities, thereby assisting clinicians in identifying high-risk patients.

Nonvitamin K Oral Anticoagulants in Patients With Atrial Fibrillation and Severe Renal Dysfunction

Both atrial fibrillation (AF) and chronic kidney disease (CKD) are highly prevalent, especially with increasing age and associated comorbidities, such as hypertension, diabetes, heart failure, and vascular disease. The relationship between both AF and CKD seems to be bidirectional: CKD predisposes to AF while onset of AF seems to lead to progression of CKD. Stroke prevention is the cornerstone of AF management, and AF patients with CKD are at higher risk of stroke, mortality, cardiac events, and bleeding. Stroke prevention requires use of oral anticoagulants, which are either vitamin K antagonists (eg, warfarin), or the nonvitamin K antagonist oral anticoagulants (NOACs). While NOACs have been shown to be effective in mild-to-moderate renal dysfunction, there are a paucity of data regarding NOACs in severe and end-stage renal dysfunction. This review first discusses the evidence for NOACs in CKD. Second, we summarize the current knowledge regarding the efficacy and safety of NOACs to prevent AF-related stroke and systemic embolism in severe and end-stage renal disease.