Atrial fibrillation in incident dialysis patients

Dialysis Modality, Transplant Characteristics, and Incident Atrial Fibrillation After Kidney Transplant: An Observational Study Using USRDS Data

Rationale & Objective

Atrial fibrillation is the most common arrhythmia and is increasing in prevalence. The prevalence of atrial fibrillation is high among patients receiving dialysis, affecting ∼21.3% of the patients receiving hemodialysis and 15.5% of those receiving peritoneal dialysis. The association of previous dialysis modality with incident atrial fibrillation in patients after receiving their first kidney transplant has not been studied.

Study Design

We used the United States Renal Data System to retrospectively identify adult, Medicare-insured patients who received their first kidney transplant between January 1, 2005, and September 30, 2012 and who had not previously been diagnosed with atrial fibrillation.

Setting & Participants

The study included 43,621 patients who were aged 18 years older when receiving a first kidney transplant between January 1, 2005, and September 30, 2012 and whose primary payer was Medicare (parts A and B) at the time of transplantation and the 6 months preceding it.

Exposure

Dialysis modality used before transplant.

Outcome

Time to incidence of atrial fibrillation up to 3 years posttransplant.

Analytical Approach

Multivariable Cox regression was used to estimate HRs.

Results

Of 43,621 patients, 84.9% received hemodialysis and 15.1% received peritoneal dialysis before transplant. The mean ± SD age was 51 ± 13.6 years; 60.8% were male, 55.6% White, and 35.8% Black race. The mean dialysis vintage was 4.3 ± 2.8 years. Newly diagnosed atrial fibrillation after kidney transplant occurred in 286 patients (during 15,363 person-years) who had received peritoneal dialysis and in 2,315 patients (during 83,536 person-years) who had received hemodialysis. After multivariable adjustment, atrial fibrillation was 20% (95% CI, 4%-38%) more likely in those who had been receiving hemodialysis versus peritoneal dialysis, regardless of whether death was considered a competing risk or a censoring event. Each year of pretransplant dialysis vintage increased the risk of posttransplant atrial fibrillation by 6% (95% CI, 3%-9%).

Limitations

Residual confounding; data from billing claims does not specify the duration of atrial fibrillation or whether it is valvular.

Conclusions

Pretransplant hemodialysis, as compared with peritoneal dialysis, was associated with higher risk of newly diagnosed atrial fibrillation after a first kidney transplant.

Plain-Language Summary

New-onset atrial fibrillation (AF) occurs in 7% of kidney transplant recipients in the first 3 years posttransplantation. We conducted this study to determine whether pretransplant dialysis modality was associated with posttransplant AF. We identified 43,621 patients; 84.9% used hemodialysis and 15.1% used peritoneal dialysis pretransplant. Multivariable Cox regression was used to estimate hazard ratios. We found that patients receiving hemodialysis pretransplant were at 20% increased risk of developing posttransplant AF as compared with patients receiving peritoneal dialysis. As our understanding of transplant-specific risk factors for AF increases, we may be able to better risk-stratify transplant patients and develop monitoring and management strategies that can improve outcomes.

Diastolic function in chronic kidney disease

Chronic kidney disease (CKD) is characterized by clustered age-independent concentric left ventricular (LV) geometry, geometry-independent systolic dysfunction and age and heart rate-independent diastolic dysfunction. Concentric LV geometry is always associated with echocardiographic markers of abnormal LV relaxation and increased myocardial stiffness, two hallmarks of diastolic dysfunction. Non-haemodynamic mechanisms such as metabolic and electrolyte abnormalities, activation of biological pathways and chronic exposure to cytokine cascade and the myocardial macrophage system also impact myocardial structure and impair the architecture of the myocardial scaffold, producing and increasing reactive fibrosis and altering myocardial distensibility. This review addresses the pathophysiology of diastole in CKD and its relations with cardiac mechanics, haemodynamic loading, structural conditions, non-haemodynamic factors and metabolic characteristics. The three mechanisms of diastole will be examined: elastic recoil, active relaxation and passive distensibility and filling. Based on current evidence, we briefly provide methods for quantification of diastolic function and discuss whether diastolic dysfunction represents a distinct characteristic in CKD or a proxy of the severity of the cardiovascular condition, with the potential to be predicted by the general cardiovascular phenotype. Finally, the review discusses assessment of diastolic function in the context of CKD, with special emphasis on end-stage kidney disease, to indicate whether and when in-depth measurements might be helpful for clinical decision making in this context.

Intravenous Thrombolysis for Acute Ischemic Stroke in Patients with End-Stage Renal Disease on Hemodialysis: A Narrative Review

OBJECTIVES

Acute ischemic stroke (AIS) is a significant and devastating complication in patients with end-stage renal disease on hemodialysis (ESRD/HD). Since one-third of AIS in ESRD/HD patients occurs during or soon after dialysis, patients are more likely to present within the time window when intravenous thrombolysis (IVT) can be performed. IVT may improve prognosis in ESRD/HD patients with AIS. However, ESRD/HD patients have been excluded from large trials and may have been withheld from IVT due to concerns about bleeding complications. To date, there is no clear evidence and firm guidance on the safety and efficacy of IVT in ESRD/HD patients with AIS. This narrative review aimed to evaluate critical scientific data on the benefits and risks of IVT use in patients with ESRD/HD and AIS.

MATERIALS AND METHODS

We searched the electronic database of PubMed for studies evaluating the relationship between AIS, ESRD/HD, and IVT. Reference sections and additional publications were also searched manually. Studies on AIS in patients with ESRD/HD requiring maintenance dialysis that referred to IVT were included.

RESULTS

In total, 560 studies were found in the PubMed electronic database during the period covered, of which 10 met the selection criteria. IVT for AIS in ESRD/HD patients could improve neurological outcomes and be safely performed even with the possibility of hemorrhagic complications associated with hypertension. Despite the high complication and mortality rates in ESRD/HD patients with AIS after IVT, the association with IVT was unclear.

CONCLUSIONS

IVT for AIS in ESRD/HD patients may improve outcomes and should not be withheld based solely on ESRD/HD status.

Association between atrial fibrillation and risk of end-stage renal disease among adults with diabetes mellitus

Diabetes mellitus (DM) is an important risk factor in patients with end-stage renal disease (ESRD). DM is associated with the development of cardiovascular diseases, such as atrial fibrillation (AF), due to poor glycemic control. However, few studies have focused on the risk of developing ESRD among DM patients with and without AF. This study evaluated ESRD risk among DM patients with and without AF in Taiwan. Data were retrieved from one million patients randomly sampled from Taiwan’s National Health Insurance Research Database, including 6,105 DM patients with AF propensity score–matched with 6,105 DM patients without AF. Both groups were followed until death, any dialysis treatment, or December 31, 2013, whichever occurred first. AF was diagnosed by a qualified physician according to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM), using the diagnostic code 427.31. Patients aged <20 years or diagnosed with ESRD before the index date were excluded. A Cox proportional hazard regression model was used to calculate the relative ESRD risk. Among DM patients, those with AF have more comorbidities than those without AF. We also found a 1.18-fold (95% confidence interval [CI]: 1.01–1.46) increase in ESRD risk among patients with AF compared with those without AF. In addition, DM patients with hypertension, chronic kidney disease (CKD), or higher Charlson Comorbidity Index scores also have significantly increased ESRD risks than those without these complications. A 1.39-fold (95% CI: 1.04–1.86) increase in risk was observed for patients with AF among the non-CKD group. Our findings suggest that patients with DM should be closely monitored for irregular or rapid heart rates.

Anticoagulation use and the risk of stroke and major bleeding in patients on hemodialysis: From the VIVALDI, a population-based prospective cohort study

BACKGROUND

Evidence supporting the use of anticoagulation for the prevention of stroke and thromboembolism in patients with kidney failure on hemodialysis (HD) and atrial fibrillation (AF) is limited. We prospectively assessed the incidences of stroke and major bleeding, as well as anticoagulation strategies in patients on HD with AF.

METHODS

We recruited 625 prevalent HD patients into a population-based observational cohort study. The primary prospective outcomes were thromboembolic events (stroke, transient ischemic attack, systemic embolism) and major bleeding. Secondary outcomes included a composite of thromboembolic events, major bleeding, and cardiovascular death to determine net clinical harm.

RESULTS

A total of 238 patients (38.1%) had AF, 165 (26.4%) already at baseline and 73 (15.9%) developed AF during a median follow up of 870 days. Forty (6.4%) thromboembolic events and 89 (14.2%) major bleedings occurred. Overall, 256 patients died (41.0%). In AF patients, use of vitamin K antagonists (VKAs) in 61 patients (25.6%) was not significantly associated with reduced risk of the primary thromboembolic outcome (subdistribution hazard ratio [SHR] 1.41 adjusted for age, sex, congestive heart failure, hypertension, stroke/transient ischemic attack/thromboembolism, vascular disease, and diabetes history score and antiplatelet co-medication (95% CI, 0.49-4.07), but with increased risk of major bleeding (SHR: 2.28; 95% CI, 1.09-4.79) compared with AF patients without anticoagulation (N = 139, 58.4%). Use of VKAs was associated with net clinical harm (adjusted SHR: 2.07; 95% CI, 1.25-3.42).

CONCLUSIONS

Although the nonrandomized nature of the study is prone to bias, anticoagulation with VKAs was not associated with decreased thromboembolic risk, but rather with increased risk of major bleeding and may be net harmful to patients with AF on HD.

Procalcitonin as a Marker of Comorbid Atrial Fibrillation in Chronic Kidney Disease and History of Sepsis

Cardiovascular disease and infection are the leading causes of mortality in patients with stage 5 chronic kidney disease on hemodialysis (CKD5-HD). Inflammation is a large component in the pathogenesis of both atrial fibrillation (AF) and sepsis and may link these conditions in CKD5-HD. Procalcitonin (PCT) is an inflammatory biomarker elevated in systemic infection and CKD5-HD, yet its value with regard to comorbid AF has not been thoroughly investigated. The aim of this study sought to evaluate circulating inflammatory markers, including PCT, Angiopoietin-1, Angiopoetin-2, CD40-L, C-reactive protein, d-dimer, and von Willebrand factor in relation to these conditions. Plasma levels of inflammatory markers were measured by enzyme linked immunosorbent assay method in CKD5-HD (n = 97) patients and controls (n = 50). Procalcitonin levels were significantly elevated (P = .0270) in CKD5-HD with comorbid AF compared to those without AF. Further analysis of patients with a history of sepsis demonstrated significantly elevated levels of PCT (P = .0405) in those with comorbid AF (160.7 ± 39.5 pg/mL) compared to those without AF (117.4 ± 25.3 pg/mL). This study demonstrates that the inflammatory biomarker PCT is further elevated in the presence of both AF and a history of sepsis in hemodialysis patients and suggests that underlying chronic inflammation following sepsis resolution may place these patients at greater risk of developing AF.

Thromboembolic and Bleeding Risk in Atrial Fibrillation Patients with Chronic Kidney Disease: Role of Anticoagulation Therapy

Atrial fibrillation (AF) and chronic kidney disease (CKD) are strictly related; several independent risk factors of AF are often frequent in CKD patients. AF prevalence is very common among these patients, ranging between 15% and 20% in advanced stages of CKD. Moreover, the results of several studies showed that AF patients with end stage renal disease (ESRD) have a higher mortality rate than patients with preserved renal function due to an increased incidence of stroke and an unpredicted elevated hemorrhagic risk. Direct oral anticoagulants (DOACs) are currently contraindicated in patients with ESRD and vitamin K antagonists (VKAs), remaining the only drugs allowed, although they show numerous critical issues such as a narrow therapeutic window, increased tissue calcification and an unfavorable risk/benefit ratio with low stroke prevention effect and augmented risk of major bleeding. The purpose of this review is to shed light on the applications of DOAC therapy in CKD patients, especially in ESRD patients.

Pathophysiology of atrial fibrillation and chronic kidney disease

Atrial fibrillation (AF) and chronic kidney disease (CKD) are closely related conditions with shared risk factors. The growing prevalence of both AF and CKD indicates that more patients will suffer from concurrent conditions. There are various complex interlinking mechanisms with important implications for the management of these patients. Furthermore, there is uncertainty regarding the use of oral anticoagulation (OAC) in AF and CKD that is reflected by a lack of consensus between international guidelines. Therefore, the importance of understanding the implications of co-existing AF and CKD should not be underestimated. In this review, we discuss the pathophysiology and association between AF and CKD, including the underlying mechanisms, risk of thrombo-embolic and bleeding complications, influence on stroke management, and evidence surrounding the use of OAC for stroke prevention.

The Impact of CKD Anaemia on Patients: Incidence, Risk Factors, and Clinical Outcomes-A Systematic Literature Review

Anaemia is a common consequence of chronic kidney disease (CKD); however, the risk factors for its development and its impact on outcomes have not been well synthesised. Therefore, we undertook a systematic review to fully characterise the risk factors associated with the presence of anaemia in patients with CKD and a contemporary synthesis of the risks of adverse outcomes in patients with CKD and anaemia. We searched MEDLINE, EMBASE, and the Cochrane Library from 2002 until 2018 for studies reporting the incidence or prevalence of anaemia and associated risk factors and/or associations between haemoglobin (Hb) or anaemia and mortality, major adverse cardiac events (MACE), hospitalisation, or CKD progression in adult patients with CKD. Extracted data were summarised as risk factors related to the incidence or prevalence of anaemia or the risk (hazard ratio (HR)) of outcome by Hb level (<10, 10-12, >12 g/dL) in patients not on dialysis and in those receiving dialysis. 191 studies met the predefined inclusion criteria. The risk factor most associated with the prevalence of anaemia was CKD stage, followed by age and sex. Mean HRs (95% CI) for all-cause mortality in patients with CKD on dialysis with Hb <10, 10-12, and >12 g/dL were 1.56 (1.43-1.71), 1.17 (1.09-1.26), and 0.91 (0.87-0.96), respectively. Similar patterns were observed for nondialysis patients and for the risks of hospitalisation, MACE, and CKD progression. This is the first known systematic review to quantify the risk of adverse clinical outcomes based on Hb level in patients with CKD. Anaemia was consistently associated with greater mortality, hospitalisation, MACE, and CKD progression in patients with CKD, and risk increased with anaemia severity. Effective treatments that not only treat the anaemia but also reduce the risk of adverse clinical outcomes are essential to help reduce the burden of anaemia and its management in CKD.

A systematic review and external validation of stroke prediction models demonstrates poor performance in dialysis patients

OBJECTIVES

The objective of this study was to systematically review and externally assess the predictive performance of models for ischemic stroke in incident dialysis patients.

STUDY DESIGN AND SETTING

Two reviewers systematically searched and selected ischemic stroke models. Risk of bias was assessed with the PROBAST. Predictive performance was evaluated within The Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD), a large prospective multicenter cohort of incident dialysis patients. For discrimination, c-statistics were calculated; calibration was assessed by plotting predicted and observed probabilities for stroke, and calibration-in-the-large.

RESULTS

Seventy-seven prediction models for stroke were identified, of which 15 were validated. Risk of bias was high, with all of these models scoring high risk in one or more domains. In NECOSAD, of the 1,955 patients, 127 (6.5%) suffered an ischemic stroke during the follow-up of 2.5 years. Compared with the original studies, most models performed worse with all models showing poor calibration and discriminative abilities (c-statistics ranging from 0.49 to 0.66). The Framingham showed reasonable calibration; however, with a c-statistic of 0.57 (95% CI 0.50-0.63), the discrimination was poor.

CONCLUSION

This external validation demonstrates the weak predictive performance of ischemic stroke models in incident dialysis patients. Instead of using these models in this fragile population, either existing models should be updated, or novel models should be developed and validated.

Prevalence and associated factors of undiagnosed atrial fibrillation among end-stage renal disease patients on maintenance haemodialysis: a cross-sectional study

BACKGROUND

Atrial fibrillation (AF) is the most prevalent sustained arrhythmia worldwide and it aggravates cardiovascular morbidity and mortality; however, this is largely under-diagnosed. Moreover, among end-stage renal disease patients on haemodialysis, AF is substantially more common and serious. The researchers conducted this study to assess the prevalence of, and the factors correlated with AF in Jordanian haemodialysis patients.

METHODS

In a cross-sectional analysis conducted from October 2018 to February 2019 in four tertiary hospitals, the researchers enrolled all consenting patients aged 18 years or older who were on haemodialysis for at least three months prior to the study. We screened for AF clinically by pulse palpation, precordial auscultation, by an automated blood pressure monitor and an electrocardiogram. The researchers reported qualitative variables as counts and frequencies, while continuous variables were summarised using the mean or median where necessary. We used multiple logistic regression with backward selection to identify independent risk factors of AF.

RESULTS

A total of 231 patients were enrolled; mean age was 54.8 ± 15.6 years (from 20 to 86), and 44.3% of them were women. The prevalence of AF was found to be 7.8% (95% CI, 4.8-12.2), with no gender disparity. Age (adjusted odds ratio [AOR] = 1.05; 95% CI, 1.01-1.10; p = 0.031), history of ischaemic heart disease (AOR = 3.74; 95% CI, 1.09-12.34; p = 0.033), history of smoking (AOR = 0.15; 95% CI, 0.02-0.60; p = 0.019), and low interdialytic weight gain (AOR = 0.50: 95% CI, 0.25-0.91; p = 0.031) were independently correlated to AF.

CONCLUSIONS

The prevalence of AF among patients on maintenance haemodialysis is high, but largely undiagnosed. AF is generally associated with advancing age, history of ischaemic heart disease, lower interdialytic weight gain, and history of smoking. We suggest routine check-up of AF in this high-risk group of patients as anticoagulant therapy if indicated may prevent serious complications. However, there is a need for large-scale cohort studies and for the creation of regional chronic kidney disease and dialysis registries in the Middle East region.

Atrial fibrillation and associated outcomes in patients with peritoneal dialysis and hemodialysis: a 14-year nationwide population-based study

BACKGROUND

Patients with end-stage renal disease (ESRD) undergoing dialysis have increased risks of atrial fibrillation (AF).

OBJECTIVE

To investigate dialysis-related incident AF and associated outcomes.

METHODS

Patients with dialysis were retrieved using data from Taiwan National Health Insurance Research Database during 2001-2013. Patients were separated into peritoneal dialysis (PD) and hemodialysis (HD) according to their initial modality. Primary outcome was new-onset AF. Secondary outcomes were AF-associated ischemic stroke (IS)/systemic embolism (SE) and hemorrhagic stroke.

RESULTS

A total of 158,910 dialytic patients were retrieved. After exclusion criteria, a total of 117,023 patients with ESRD undergoing dialysis were separated into 12,659 patients on PD and 104,364 patients on HD. There were 458 PD patients with subsequent development of AF, and 6216 HD patients with subsequent development of AF. At end of follow-up, patients on PD and HD had AF incidence densities of 7.8 and 8.8 events per 1000 person-years, the SHR of PD versus HD was 0.83 (95% CI 0.73-0.94). The SHR of PD versus HD was 1.07 (95% CI 0.80-1.44) for IS/SE and the SHR of PD versus HD was 0.34 (95% CI 0.13-0.90) for hemorrhagic stroke.

CONCLUSION

In patients with ESRD undergoing dialysis, PD had lowered risks of new onset of AF compared to HD. Subsequently, these AF patients in PD group had comparable incidence of ischemic stroke but decreased incidence of hemorrhagic stroke compared to AF patients in HD group. PD could be the most suitable modality in patients at risk for the onset of AF.

Stroke and Bleeding Risk Assessments in Patients With Atrial Fibrillation: Concepts and Controversies

Risk assessments are an important element in the management of patients with atrial fibrillation (AF). In this review, we aim to discuss the concepts and controversies surrounding the various risk factors for stroke and bleeding in AF. Indeed, there are a variety of clinical, electrical, biological, and genetic markers to guide stroke and bleeding risk assessments in AF. The more common factors have been used to formulate risk stratification scores. Some risk factors have shown promise, but others remain less well-defined. Our aim is to discuss concepts and controversies surrounding current evidence of risk factors for stroke and bleeding assessments in AF.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern

BACKGROUND

Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC.

SUMMARY

This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

Incidence rate of atrial fibrillation after dialysis initiation and its relationship with cardiovascular events

Aim: This study aimed to investigate the incidence of atrial fibrillation (AF) and its prognosis in the patients after dialysis initiation.Methods: A total of 1524 patients with chronic kidney disease who were initiated on dialysis were included. Dialysis was initiated between October 2011 and September 2013. Electrocardiogram was obtained at dialysis initiation, in March 2015, and September 2016. The mortality and cardiovascular disease (CVD) event rates of 1520 patients (1028 men and 492 women; mean age, 67.5 ± 13.1 years) who were followed up were compared, and they were divided into 2 groups: the AF group (with AF at least once) and N group (without AF).Results: The prevalence of AF was 6.2, 7.9, and 6.5% at dialysis initiation, in March 2015, and September 2016, respectively, and the incidence of new AF onset was 4.8% in March 2015 and 2.3% in September 2016. In total, 45 (28.0%) and 347 (25.5%) patients died in the AF and N groups, (p = .508), respectively. The incidence rates of CVD event were 91 (56.5%) and 413 (30.4%) in the AF and N groups (p < .001), respectively. In the multivariate analysis, mortality was not significant, but the incidence of CVD event was significantly higher in the AF group. Albumin level was associated with new-onset AF.Conclusions: After dialysis initiation, a high incidence of new-onset AF was observed. The lower albumin value at the time of dialysis initiation is more likely to be associated with AF development. Attention should be paid to the CVD events in the AF group.

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.

Arrhythmias in Patients on Maintenance Dialysis: A Cross-sectional Study

RATIONALE & OBJECTIVE

Patients with kidney failure treated with maintenance dialysis experience a high rate of mortality, in part due to sudden cardiac death caused by arrhythmias. The prevalence of arrhythmias, including the subset that are clinically significant, is not well known. This study sought to estimate the prevalence of arrhythmias, characterize the pattern of arrhythmic events in relation to dialysis treatments, and identify associated clinical characteristics.

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

152 patients with kidney failure treated with maintenance dialysis in Denmark.

EXPOSURES

Dialysis treatment; clinical characteristics; cardiac output and preload defined using echocardiography.

OUTCOMES

Prevalence and pattern of arrhythmias on 48-hour Holter monitoring; odds ratios for arrhythmias.

ANALYTICAL APPROACH

Descriptive analysis of the prevalence of arrhythmias. Pattern of arrhythmias described using a repeated-measures negative binomial regression model. Associations between clinical characteristics and echocardiographic findings with arrhythmias were assessed using logistic regression.

RESULTS

Among the 152 patients studied, 83.6% were treated with in-center dialysis; 10.5%, with home hemodialysis; and 5.9%, with peritoneal dialysis. Premature atrial and ventricular complexes were seen in nearly all patients and 41% had paroxysmal supraventricular tachycardia. Clinically significant arrhythmias included persistent atrial fibrillation observed among 8.6% of patients, paroxysmal atrial fibrillation among 3.9%, nonsustained ventricular tachycardia among 19.7%, bradycardia among 4.6%, advanced second-degree atrioventricular block among 1.3%, and third-degree atrioventricular block among 2.6%. Premature ventricular complexes were more common on dialysis days, while tachyarrhythmias were more often observed during dialysis and in the immediate postdialytic period. Older age (OR per 10 years older, 1.53; 95% CI, 1.15-2.03; P=0.003), elevated preload (OR, 4.02; 95% CI, 1.05-15.35; P=0.04), and lower cardiac output (OR per 1L/min greater, 0.66; 95% CI, 0.44-1.00; P=0.05) were independently associated with clinically significant arrhythmias.

LIMITATIONS

Arrhythmia monitoring limited to 48 hours; small sample size; heterogeneous nature of the population, risk for residual confounding.

CONCLUSIONS

Arrhythmias, including clinically significant abnormal rhythms, were common. Tachyarrhythmias were more frequent during dialysis and the immediate postdialytic period. The relevance of these findings to clinical outcomes requires additional study.

Clinical Pharmacology of Oral Anticoagulants in Patients with Kidney Disease

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

Beta-blockers use from the general to the hemodialysis population

Beta-blockers have numerous indications in the general population and are strongly recommended in heart failure, post-myocardial infarction and arrhythmias. In hemodialysis patients, their use is based on weak evidence because of the lack of a sufficient number of randomized clinical trials. The strongest evidence is based on two trials. The first showed better survival with carvedilol in hemodialysis patients with four sessions per week and systolic heart failure. The second found reduced cardiovascular morbidity with atenolol compared to lisinopril in mostly black hypertensive hemodialysis patients. No clinical trials exist regarding myocardial infarction. Large retrospective studies have assessed the benefits of beta-blockers in hemodialysis. A large cohort of hemodialysis patients with new-onset heart failure showed better survival when treated with carvedilol, bisoprolol or metoprolol. Another recent one of 20,064 patients found out that metoprolol compared to carvedilol was associated with less all-cause mortality. There is still uncertainty also regarding the impact of dialysability of beta-blockers on patient's survival. On top of that, many observations suggested that beta-blockers were associated with a reduced rate of sudden cardiac death in hemodialysis patients but recent data show a link between bradycardia and sudden cardiac death questioning the benefit of beta-blockade in this population. Finally, what we know for sure so far is that beta-blockers should be avoided in patients with intradialytic hypotension associated with bradycardia.

Icodextrin is associated with a lower risk of atrial fibrillation in peritoneal dialysis patients

AIM

Dialysis patients with atrial fibrillation (AF) are at 1.72-fold increased mortality risk. This study investigated whether peritoneal dialysis (PD) patients using icodextrin were at a reduced risk of AF.

METHODS

From the Taiwan National Health Insurance database, we identified 4040 icodextrin users and 3517 non-users among 7557 patients newly diagnosed with end-stage renal disease undergoing PD from 2005 to 2011. The incidence of AF was compared between PD patients with and without icodextrin treatment by the end of 2011, with the hazard ratio (HR) of AF measured using Cox proportional hazards regression models.

RESULTS

The incidence of AF was 50% lower in icodextrin users than in non-users (2.14 vs 4.24 per 1000 person-years) with an adjusted HR of 0.49 (95% confidence interval (CI) = 0.28-0.85). The protective effect was greater for PD patients with diabetes (adjusted HR = 0.39, 95% CI = 0.17-0.86) than those without diabetes (adjusted HR = 0.57, 95% CI = 0.28-1.18). The beneficial effect of icodextrin treatment remained after controlling for the competing risk of deaths, with an adjusted sub-HR of 0.35 (95% CI = 0.16-0.75) for those with diabetes and 0.50 (95% CI = 0.26-0.99) for those without diabetes.

CONCLUSION

The use of icodextrin solution is associated with a lower risk of new-onset AF in PD patients. The protective effectiveness was greater for those with diabetes.

Comparison of atrial fibrillation in CKD and non-CKD populations: A cross-sectional analysis from the Kailuan study

OBJECTIVES

To compare clinical epidemiological features of atrial fibrillation (AF) in chronic kidney disease (CKD) and non-CKD populations.

METHODS

This study included 88,312 adults aged ≥45 years old from the KAILUAN study. AF was ascertained with a 12-lead electrocardiogram. CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² and/or proteinuria. Participants were categorized into non-CKD (eGFR > 60 mL/min/1.73 m² without proteinuria, n = 66,725) and CKD (n = 21,578) groups. We evaluated the prevalence of AF in both groups, evaluated risk factors for AF using multivariable-adjusted logistic regression analysis.

RESULTS

The prevalence of AF among non-CKD and CKD participants was 0.26% and 1.00%, respectively. Multivariable-adjusted analysis showed that older age (odds ratio [OR]: 1.08, 95% confidence interval [CI]: 1.07-1.10, P < 0.001), smoking (OR: 1.23, 95% CI: 1.07-1.57, P = 0.017), hypertension (OR: 2.14, 95% CI: 1.44-3.17, P < 0.001), diabetes (OR: 1.79, 95% CI: 1.10-2.89, P < 0.001), and larger waist circumference (OR: 1.03, 95% CI: 1.01-1.04, P < 0.001) were significantly associated with AF in the non-CKD group. In the CKD group, older age, smoking, larger waist circumference, reduced eGFR (OR: 0.97, 95% CI: 0.95-0.99, P < 0.001), proteinuria (OR: 2.01, 95% CI: 1.09-3.74, P < 0.001) and raised serum C-reactive protein (1.01, 1.00-1.03, P < 0.001) were significantly associated with AF.

CONCLUSIONS

The prevalence of AF in Chinese adults with CKD is higher than that among those without CKD. Risk factors for AF in non-CKD population were not the same compared with those in CKD population, kidney function and inflammatory markers were associated with the prevalence of AF.

Dialysis Modality and Incident Atrial Fibrillation in Older Patients With ESRD

RATIONALE & OBJECTIVE

Atrial fibrillation (AF) is common in patients with kidney failure treated by maintenance dialysis. Whether the incidence of AF differs between patients receiving hemodialysis and peritoneal dialysis is uncertain.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Using the US Renal Data System, we identified older patients (≥67 years) with Medicare Parts A and B who initiated dialysis therapy (1996-2011) without a diagnosis of AF during the prior 2 years.

EXPOSURE

Dialysis modality at incident end-stage renal disease (ESRD) and maintained for at least 90 days.

OUTCOME

Patients were followed up for 36 months or less for a new diagnosis of AF.

ANALYTICAL APPROACH

Time-to-event analysis using multivariable Cox proportional hazards regression to estimate cause-specific HRs while censoring at modality switch, kidney transplantation, or death.

RESULTS

Overall, 271,722 older patients were eligible; 17,487 (6.9%) were treated with peritoneal dialysis, and 254,235 (93.1%), with hemodialysis, at the onset of ESRD. During 406,225 person-years of follow-up, 69,705 patients had AF newly diagnosed. Because the proportionality assumption was violated, we introduced an interaction term between time (first 90 days vs thereafter) and modality. The AF incidence during the first 90 days was 187/1,000 person-years on peritoneal dialysis therapy and 372/1,000 person-years on hemodialysis therapy. Patients on peritoneal dialysis therapy had an adjusted 39% (95% CI, 34%-43%) lower incidence of AF than those on hemodialysis therapy. From day 91 onward, AF incidence was ∼140/1,000 person-years with no major difference between modalities.

LIMITATIONS

Residual confounding from unobserved differences between exposure groups; ascertainment of AF from billing claims; study of first modality may not generalize to patients switching modalities; uncertain generalizability to younger patients.

CONCLUSIONS

Although patients initiating dialysis therapy using peritoneal dialysis had a lower AF incidence during the first 90 days of ESRD, there was no major difference in AF incidence thereafter. The value of interventions to reduce the early excess AF risk in patients receiving hemodialysis may warrant further study.

Biomarker Profiling in Stage 5 Chronic Kidney Disease Identifies the Relationship between Angiopoietin-2 and Atrial Fibrillation

Atrial fibrillation (AF) is prevalent in nearly 27% of patients with stage 5 chronic kidney disease on hemodialysis (CKD5-HD), suggesting a strong association between these 2 pathologies. It is hypothesized that the relationship between these 2 diseases may be mediated by inflammation. Angiopoietin-2 (Ang-2), a pro-inflammatory biomarker of endothelial instability, inflammation, and vascular remodeling, is elevated in CKD5-HD and AF, yet has not been evaluated in patients with concomitant AF and CKD5-HD. The aim of this study is to analyze circulating levels of inflammatory and thrombotic biomarkers in patients with concomitant AF and CKD5-HD. Plasma levels of Ang-2 were measured via sandwich enzyme-linked immunosorbent assay method in CKD5-HD patients (n = 96), patients with AF (n = 38), and controls (n = 50). Angiopoietin-2 was markedly elevated in CKD5-HD with comorbid AF as compared to CKD5-HD alone, and AF alone, respectively (13.05 ± 1.56 vs 9.57 ± 0.71 ng/mL; P = .00169; vs 2.48 ± 0.57 ng/mL; P < .0001). The results of this study suggest an additive effect of Ang-2 with coexistence of AF and CKD5-HD, which may be useful in the detection of AF within this patient population.

Factors influencing P terminal force in lead V1 of the ECG in hemodialysis patients

INTRODUCTION

Atrial fibrillation (AF) is a highly prevalent arrhythmia in hemodialysis (HD) patients, and an HD session may be a trigger for AF episodes. An abnormal P-terminal force in lead V1 (PTFV1) may predict new-onset AF in HD patients. The aim of the study was to assess the influence of the HD process on PTFV1 and to evaluate possible factors influencing PTFV1 in a group of selected HD patients.

MATERIAL AND METHODS

One hundred and fifty-three selected HD patients entered the study. Blood chemistry, electrocardiography, and impedance cardiography were evaluated before and after HD. Echocardiography was performed on the morning after dialysis. Abnormal PTFV1 was defined as PTFV1 > 40 mm × ms.

RESULTS

Abnormal PTFV1 was found in 35.3% of patients before dialysis and in 48.4% of patients after dialysis. The results of multiple regression analysis revealed that the independent predictors of pre-dialysis abnormal PTFV1 were: left atrial volume index (p = 0.002), left ventricular mass index (p = 0.014), and pre-dialysis thoracic fluid content (p = 0.021) values. The independent predictors of HD-induced abnormal PTFV1 values were larger differences between pre-dialysis and post-dialysis values of serum potassium (p < 0.001) and mean arterial pressure (p = 0.008).

CONCLUSIONS

Abnormal PTFV1 is prevalent in HD patients. The HD process adversely affects PTFV1 values. Pre-dialysis abnormal PTFV1 is mainly associated with structural heart abnormalities and hydration status. HD-induced abnormal PTFV1 is associated predominantly with serum potassium changes as well as HD-induced hypotension. Our results suggest possible risk factors for AF; however, their clinical significance needs to be confirmed in follow-up studies.

Is anticoagulating haemodialysis patients with non-valvular atrial fibrillation too risky?

There is an increasing understanding of the risks from atrial fibrillation (AF) in the current era. In patients with end-stage renal disease (ESRD) on dialysis, the prevalence of AF is significantly higher compared to the general population and those with earlier stages of CKD. Although anticoagulation of these patients may seem appropriate, there is a lack of conclusive evidence that it provides the same protection from thromboembolic complications as it does in patients not on dialysis. In addition, the increased risk of bleeding in patients requiring dialysis makes the use of anticoagulants less favourable. This article aims to discuss the problem of AF in dialysis patients, summarise the current evidence around the use of oral anticoagulants for AF in ESRD and provide some practical suggestions on management of AF in the haemodialysis population.

DOAC use in patients with chronic kidney disease

Direct oral anticoagulants (DOACs) are increasingly prescribed substances in patients with indication for effective anticoagulation. Patients with chronic kidney disease (CKD) have a high burden of cardiovascular risk and are more likely to develop atrial fibrillation (AF) than patients without CKD. Patients with mild to moderate CKD benefit from DOACs, especially when having intolerance to vitamin K-antagonists (VKA). DOACs may in some cases be considered in patients with rare renal disease and hypercoagulabilic state. DOACs are to a large extent eliminated by renal excretion. Since prospective randomised data in CKD patients are sparse, the decision for anticoagulative therapy is challenging especially in patients with severe renal impairment. The direct factor Xa-inhibitors are approved for use even in patients with an estimated glomerular filtration rate (eGFR) between 15 and 30 ml/min. Careful monitoring of renal function on a regular basis is essential before initiation and after start of DOAC, especially for patients at risk for acute renal failure (elderly, diabetics, patients with preexisting kidney disease). None of the DOACs is approved in CKD patients with end-stage-renal-disease (ESRD) with or without dialysis. DOACs are not recommended for kidney transplant patients under immunosuppression with calcineurin inhibitors. In these patients conventional therapy with VKA is the only option, which has to be monitored closely since it has potential adverse effects.

Impact of Chronic Kidney Disease on the Presentation and Outcome of Patients Hospitalized With Atrial Fibrillation: Insights From Qatar

Atrial fibrillation (AF) with coexistent chronic kidney disease (CKD) is poorly described in the literature. We compared the presenting symptoms, clinical characteristics, treatment, and outcome of patients hospitalized with AF with and without CKD in a large clinical registry. Data of patients hospitalized with AF between 1991 and 2012 in Qatar were analyzed. Of 5201 patients hospitalized for AF, 264 (5.1%) had CKD. Patients with AF and CKD were older with higher prevalence of other comorbidities and left ventricular dysfunction and were more likely to present with shortness of breath and chest pain compared with patients with AF alone who were more likely to present with palpitation. The crude in-hospital mortality was 3 times higher in patients with dual disease. On multivariable adjustments, CKD was an independent predictor of mortality (odds ratio: 2.84; 95% confidence interval: 1.33-6.08, P = .001). Further studies are warranted to try to reduce the increased mortality observed in this high-risk population.

Predicting in a predicament: Stroke and hemorrhage risk prediction in dialysis patients with atrial fibrillation

Whether to anticoagulate dialysis patients with atrial fibrillation is a common clinical dilemma with limited high-quality data to inform decision-making. While the efficacy and safety of anticoagulation for stroke prevention in dialysis patients with atrial fibrillation has long been debated and remains unclear, the more upstream issue of stroke risk assessment from atrial fibrillation has received relatively little attention. In the general population, a handful of risk scores to help predict stroke and hemorrhage risk in the setting of atrial fibrillation are widely validated and applied in clinical practice. But are they applicable to the dialysis population? The most commonly used stroke risk scores, CHADS2 and CHA2DS2-VASC, have limited validation in the dialysis population, and when validated, have shown poor performance (c-statistics <0.70). Stroke risk scores derived in the general atrial fibrillation population may perform poorly in dialysis patients for a number of reasons. Dialysis patients have unique stroke risk factors, such as chronic inflammation and vascular calcification, and a much higher competing risk of death, none of which are accounted for in current risk scores. Further complicating the dilemma of anticoagulation is hemorrhage risk, which is known to be exceedingly high in dialysis patients. Currently available hemorrhage risk scores, such as HAS-BLED, have not been validated in dialysis patients and will likely underestimate hemorrhage risk. Moving forward, risk tools specific to the dialysis population are needed to accurately assess and balance stroke and hemorrhage risks in dialysis patients with atrial fibrillation.

Real-world stroke prevention strategies in nonvalvular atrial fibrillation in patients with renal impairment

BACKGROUND

The data regarding stroke prevention strategies in nonvalvular atrial fibrillation (NVAF) are limited especially in patients with renal impairment (RI). We sought to evaluate management dilemmas in patients with concurrent NVAF and RI in RAMSES (ReAl-life Multicenter Survey Evaluating Stroke Prevention Strategies inTurkey) study.

METHODS

We conducted a prospective, multicenter, nation-wide registry in NVAF patients in outpatient cardiology clinics. All consecutive patients with NVAF were enrolled in RAMSES study (ClinicalTrials.gov identifier NCT02344901). The baseline data were collected. Glomerular filtration rate (GFR) was estimated by Cockcroft-Gault equation.

RESULTS

A total number of 6273 patients from 29 provinces of Turkey with the contribution of 83 investigators were enrolled to the study. Of the study population, 1964(33%) patients had RI which was defined as GFR < 60 mL/min. Patients with RI had significantly higher CHA₂ DS₂ VASc and HAS-BLED scores compared to those without RI (3·9 ± 1·5 vs. 2·9 ± 1·5, and 2·0 ± 1 vs. 1·4 ± 1; P < 0·001). Prior history of major bleeding (6·9% vs. 4·1%, P < 0·001) and stroke (16·2% vs. 11·8%, P < 0·001) was significantly higher among individuals with concomitant RI and NVAF. Although RI patients had a higher risk for thromboembolism, number of the patients who did not receive any anticoagulant therapy was higher in patients with RI than without RI (30·1 vs. 26·4%, P = 0·003).

CONCLUSION

RAMSES study showed that one-third of the patients with NVAF had RI in the real-world setting. Although it is mandatory in most of the patients with concomitant NVAF and RI, nearly one-third of these patients did not receive any anticoagulant therapy.

Bleeding Risk of Antithrombotic Treatment in Patients on Hemodialysis

BACKGROUND

The risk-benefit of antithrombotic treatment (ATT) has not been established in patients on dialysis. Our objective was to determine the influence of ATT on the risk of hemorrhage in patients on hemodialysis.

METHODS

We included patients who began dialysis between 2003 and 2007. We determined the rates of fatal bleeding or bleeding leading to hospitalization or transfusion.

RESULTS

Two hundred twenty-one patients were included. Over the follow-up period (45.5 ± 34 months), there were 76 hemorrhages in 52 patients. There were 10 fatal bleedings. The annual incidence of patients presenting with hemorrhagia was 6.2%. Bleeding occurred in 5.2% of those being treated with aspirin, 7% with acenocumarol, 12.3% with clopidogrel, 15.2% with aspirin + clopidogrel, 45.9% with anticoagulants + antiplatelets, 49.6% with low-molecular-weight heparin, and 3.9% without ATT. On multivariate analysis, masculine gender [hazard ratio (HR): 2.421; 95% confidence interval (CI), 1.261-4.650; P = 0.003], treatment with dicumarins (HR: 2.406; 95% CI, 1.013-5.718; P = 0.047), treatment with clopidogrel (HR: 2.697; 95% CI, 1.440-5.051; P = 0.002), and treatment with low-molecular-weight heparin (HR: 21.463; 95% CI, 9.067-50.806; P = 0.001) were independent predictors of bleeding.

CONCLUSIONS

ATT increases the risk of bleeding in patients on hemodialysis. The incidence of hemorrhage varies with the type of antithrombotics used.

The occurrence of atrial fibrillation in dialysis patients and its association with left atrium volume before and after dialysis

PURPOSE

Atrial fibrillation is a serious problem, especially in patients on dialysis. The prevalence of AF in this group of patients is higher than in general population and associated with increased mortality. The aim of this study was to assess the risk of the occurrence of atrial fibrillation related to intradialysis hypotension and left atrium volume enlargement associated with dialysis. The influence of dialysis session on: E/E', V LA, E/A, E', V RA and the width of inferior vena cava of RV was analyzed.

METHODS

This study included 40 patients on hemodialysis. Echocardiographic examination was performed to assess heart condition and function, the presence of LVH and systolic and diastolic function disturbances, LV mass, LA size, LAV, RAV, E/A, E', E/E, ejection fraction in all patients before and after dialysis. Moreover, all patients had ECG Holter continuously recording heart's rhythm before and after dialysis to assess the occurrence of atrial fibrillation related to dialysis session.

RESULTS

The analysis of differences in echocardiographic parameters before and after dialysis demonstrated significantly greater left atrium volume, right atrium volume, width of inferior vena cava and e' parameter before dialysis in comparison with post-dialysis state. Significantly higher incidence of AF after dialysis was seen. Volume of left atrium exceeding 32 mm (cutoff value) was observed significantly more often in patients before dialysis. No association was observed between left ventricle mass and left atrium volume.

CONCLUSIONS

The dialysis procedure may be a trigger for atrial fibrillation and thus AF preventive measures should be introduced in dialysis patients.

Prevalence of Atrial Fibrillation and Antithrombotic Therapy in Hemodialysis Patients: Cross-Sectional Results of the Vienna InVestigation of AtriaL Fibrillation and Thromboembolism in Patients on HemoDIalysis (VIVALDI)

Background

Atrial fibrillation (AF) adds significant risk of stroke and thromboembolism in patients on hemodialysis (HD). The aim of this study was to investigate the prevalence of AF in a population-based cohort of HD patients and practice patterns of antithrombotic therapy for stroke prevention in AF.

Methods

The Vienna InVestigation of AtriaL fibrillation and thromboembolism in patients on hemodialysis (VIVALDI), an ongoing prospective observational cohort study, investigates the prevalence of AF and the risk of thromboembolic events in HD patients in Vienna, Austria. We analyzed cross-sectional data of 626 patients (63.4% men, median age 66 years, approx. 73% of HD patients in Vienna), who provided informed consent. A structured interview with each patient was performed, recent and archived ECGs were viewed and medical histories were verified with electronic records.

Results

The overall prevalence of AF was 26.5% (166 patients, 71.1% men, median age 72 years) of which 57.8% had paroxysmal AF, 3.0% persistent AF, 32.5% permanent AF, and 6.6% of patients had newly diagnosed AF. The median CHA₂DS₂-VASc Score was 4 [25^th-75^th percentile 3–5]. In multivariable analysis, AF was independently associated with age (odds ratio: 1.05 per year increase, 95% confidence interval: 1.03–1.07), male sex (1.7, 1.1–2.6), history of venous thromboembolism (2.0, 1.1–3.6), congestive heart failure (1.7, 1.1–2.5), history of or active cancer (1.5, 1.0–2.4) and time on HD (1.08 per year on HD, 1.03–1.13). Antithrombotic treatment was applied in 84.4% of AF patients (anticoagulant agents in 29.5%, antiplatelet agents in 33.7%, and both in 21.1%). In AF patients, vitamin-K-antagonists were used more often than low-molecular-weight heparins (30.1% and 19.9%).

Conclusions

The prevalence of AF is high amongst HD patients and is associated with age, sex, and distinct comorbidities. Practice patterns of antithrombotic treatment indicate a lack of consensus for stroke prevention in HD patients with AF.

Cardiovascular impact in patients undergoing maintenance hemodialysis: Clinical management considerations

Patients undergoing maintenance hemodialysis develop both structural and functional cardiovascular abnormalities. Despite improvement of dialysis technology, cardiovascular mortality of this population remains high. The pathophysiological mechanisms of these changes are complex and not well understood. It has been postulated that several non-traditional, uremic-related risk factors, especially the long-term uremic state, which may affect the cardiovascular system. There are many cardiovascular changes that occur in chronic kidney disease including left ventricular hypertrophy, myocardial fibrosis, microvascular disease, accelerated atherosclerosis and arteriosclerosis. These structural and functional changes in patients receiving chronic dialysis make them more susceptible to myocardial ischemia. Hemodialysis itself may adversely affect the cardiovascular system due to non-physiologic fluid removal, leading to hemodynamic instability and initiation of systemic inflammation. In the past decade there has been growing awareness that pathophysiological mechanisms cause cardiovascular dysfunction in patients on chronic dialysis, and there are now pharmacological and non-pharmacological therapies that may improve the poor quality of life and high mortality rate that these patients experience.

Asymptomatic Intradialytic Supraventricular Arrhythmias and Adverse Outcomes in Patients on Hemodialysis

BACKGROUND AND OBJECTIVES

Supraventricular arrhythmias are associated with high morbidity and mortality. Nevertheless, this condition has received little attention in patients on hemodialysis. The objective of this study was to analyze the incidence of intradialysis supraventricular arrhythmia and its long-term prognostic value.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We designed an observational and prospective study in a cohort of patients on hemodialysis with a 10-year follow-up period. All patients were recruited for study participation and were not recruited for clinical indications. The study population comprised 77 patients (42 men and 35 women; mean age =58±15 years old) with sinus rhythm monitored using a Holter electrocardiogram over six consecutive hemodialysis sessions at recruitment.

RESULTS

Hypertension was present in 68.8% of patients, and diabetes was present in 29.9% of patients. Supraventricular arrhythmias were recorded in 38 patients (49.3%); all of these were short, asymptomatic, and self-limiting. Age (hazard ratio, 1.04 per year; 95% confidence interval, 1.00 to 1.08) and right atrial enlargement (hazard ratio, 4.29; 95% confidence interval, 1.30 to 14.09) were associated with supraventricular arrhythmia in the multivariate analysis. During a median follow-up of 40 months, 57 patients died, and cardiovascular disease was the main cause of death (52.6%). The variables associated with all-cause mortality in the Cox model were age (hazard ratio, 1.04 per year; 95% confidence interval, 1.00 to 1.08), C-reactive protein (hazard ratio, 1.04 per 1 mg/L; 95% confidence interval, 1.00 to 1.08), and supraventricular arrhythmia (hazard ratio, 3.21; 95% confidence interval, 1.29 to 7.96). Patients with supraventricular arrhythmia also had a higher risk of nonfatal cardiovascular events (hazard ratio, 4.32; 95% confidence interval, 2.11 to 8.83) and symptomatic atrial fibrillation during follow-up (hazard ratio, 17.19; 95% confidence interval, 2.03 to 145.15).

CONCLUSIONS

The incidence of intradialysis supraventricular arrhythmia was high in our hemodialysis study population. Supraventricular arrhythmias were short, asymptomatic, and self-limiting, and although silent, these arrhythmias were independently associated with mortality and cardiovascular events.

Cardiovascular and Stroke Risk in Japanese Hemodialysis Patients With Atrial Fibrillation

Atrial fibrillation is one of the most common arrhythmias in hemodialysis patients. We evaluated its clinical outcomes among hemodialysis patients with atrial fibrillation in Japan. Using data derived from the Japanese Dialysis Outcomes and Practice Patterns Study, we analyzed backgrounds and outcomes among hemodialysis patients with and without atrial fibrillation in Japan. Among 7002 hemodialysis patients, the prevalence of atrial fibrillation was 5.7% and the incidence was 0.2 per 100 patient-years. Atrial fibrillation was independently associated with all-cause mortality (hazard ratio, 1.32; 95% confidence interval, 1.02-1.71) and cardiovascular events (hazard ratio, 1.39; 95% confidence interval, 1.15-1.68), but not with stroke events (hazard ratio, 0.77; 95% confidence interval, 0.55-1.06) after adjustment for other variables. We conclude that patients with atrial fibrillation experienced higher mortality and more cardiovascular events than did patients without atrial fibrillation, although the risk of stroke was lower than expected.

Increased risk of atrial fibrillation in end-stage renal disease patients on dialysis: A nationwide, population-based study in Taiwan

End-stage renal disease (ESRD) patients commonly have a higher risk of developing cardiovascular diseases than general population. Chronic kidney disease is an independent risk factor for atrial fibrillation (AF); however, little is known about the AF risk among ESRD patients with various modalities of renal replacement therapy. We used the Taiwan National Health Insurance Research Database to determine the incident AF among peritoneal dialysis (PD) and hemodialysis (HD) patients in Taiwan.Our ESRD cohort include Taiwan National Health Insurance Research Database, we identified 15,947 patients, who started renal replacement therapy between January 1, 2002 and December 31, 2003. From the same data source, 47,841 controls without ESRD (3 subjects for each patient) were identified randomly and frequency matched by gender, age (±1 year), and the year of the study patient's index date for ESRD between January 1, 2002 and December 31, 2003.During the follow-up period (mean duration: 8-10 years), 3428 individuals developed the new-onset AF. The incidence rate ratios for AF were 2.07 (95% confidence interval [CI] = 1.93-2.23) and 1.78 (95% CI = 1.30-2.44) in HD and PD groups, respectively. After we adjusted for age, gender, and comorbidities, the hazard ratios for the AF risk were 1.46 (95% CI = 1.32-1.61) and 1.32 (95% CI = 1.00-1.83) in HD and PD groups, respectively. ESRD patients with a history of certain comorbidities including hypertension, diabetes mellitus, hyperlipidemia, coronary artery disease, heart failure, valvular heart disease, and chronic obstructive pulmonary disease (COPD) have significantly increased risks of AF.This nationwide, population-based study suggests that incidence of AF is increased among dialysis ESRD patients. Furthermore, we have to pay more attention in clinical practice and long-term care for those ESRD patients with a history of certain comorbidities.

Atrial fibrillation in dialysis patients: time to abandon warfarin?

Atrial fibrillation (AF) is a frequent clinical complication in dialysis patients, and warfarin therapy represents the most common approach for reducing the risk of stroke in this population. However, current evidence based on observational studies, offer conflicting results, whereas no randomized controlled trials have been carried out so far. Additionally, many clinicians are wary of the possible role of warfarin as vascular calcification inducer and its potential to increase the high risk of bleeding among patients on dialysis. Ideally the most promising therapy would be based on direct inhibitors of factor IIa or Xa; however, at the moment, none of these drugs can be safely prescribed in dialysis patients, because of their potentially dangerous accumulation, and the lack of sufficient experience with apixaban or rivaroxaban, two drugs showing a favorable pharmacokinetic profile in end-stage renal disease. Hence, the use of vitamin K inhibitors is currently the only pharmacological option for stroke prevention in dialysis patients with atrial fibrillation, leaving the clinicians in a management conundrum.This review discusses the trade-offs implicated in warfarin use for this population, the promises of newly developed drugs, the role of dialysis as atrial fibrillation trigger, as well as potential non-pharmacological management options suitable in selected clinical situations.

Warfarin Use and Risk of Stroke in Patients With Atrial Fibrillation Undergoing Hemodialysis: A Meta-Analysis

In spite of the substantial burden of atrial fibrillation and associated elevated ischemic stroke risk in patients undergoing hemodialysis, the role of warfarin in these high-risk patients remains uncertain. Our objective was to clarify the association between warfarin use and risk of stroke for patients with atrial fibrillation undergoing dialysis.PubMed and Embase from January 1966 to January 2015 were searched to identify relevant studies. Inclusion criteria were cohort studies, patients with atrial fibrillation undergoing hemodialysis, and reported quantitative estimates of the multivariate adjusted relative risk (RR) and 95% confidence interval (CI) for future stroke associated with warfarin use. We identified 8 studies, with a total of 9539 participants and 706 stroke events. Three studies reported total stroke as primary endpoint and other studies reported ischemic stroke as primary endpoint. Pooling the results showed that warfarin use was associated with higher risk of any stroke (RR 1.50, 95% CI: 1.13-1.99). By stroke type, warfarin was not significantly linked to risk of ischemic stroke (RR 1.01, 95% CI: 0.65-1.57, P = 0.97), but was related to greater hemorrhagic stroke risk (RR 2.30, 95% CI: 1.62-3.27). Warfarin heightened overall bleeding risk (RR 1.27, 95% CI: 1.03-1.56), but not death (RR 0.67, 95% CI: 0.37-1.21).Among patients with atrial fibrillation undergoing hemodialysis, use of warfarin is associated with a higher risk of hemorrhagic stroke, but did not increase overall mortality.

Risks of Death and Stroke in Patients Undergoing Hemodialysis With New-Onset Atrial Fibrillation: A Competing-Risk Analysis of a Nationwide Cohort

BACKGROUND

Whether oral anticoagulant use should be considered in patients undergoing hemodialysis with atrial fibrillation (AF) remains controversial because of the uncertainty regarding risk-benefit assessments. The purpose of this study was to investigate the risk of ischemic stroke in patients undergoing hemodialysis with new-onset AF, in comparison with those without arrhythmia.

METHODS AND RESULTS

This nationwide, population-based, propensity score-matched cohort study used data from Taiwan's National Health Insurance Research Database during 1998 to 2011 for patients on hemodialysis with new-onset nonvalvular AF and matched subjects without arrhythmia. The clinical end points were ischemic stroke (fatal or nonfatal), all-cause death, and other serious adverse cardiovascular events. In comparison with the matched cohort, patients with AF (n=6772) had higher risks of ischemic stroke (adjusted hazard ratio [aHR], 1.27; 95% confidence interval [CI], 1.13-1.43), all-cause death (aHR, 1.59; 95% CI, 1.52-1.67), in-hospital cardiovascular death (aHR, 1.83; 95% CI, 1.71-1.94), myocardial infarction (aHR, 1.33; 95% CI, 1.17-1.51), and hospitalization for heart failure (aHR, 1.90; 95% CI, 1.76-2.05). After considering in-hospital death as a competing risk, AF significantly increased the risk of heart failure (HR, 1.56; 95% CI, 1.45-1.68), but not those of ischemic stroke and myocardial infarction. Additionally, the predictive value of the CHA2DS2-VASc score for ischemic stroke was diminished in the competing-risk model.

CONCLUSIONS

The risk of stroke was only modestly higher in patients undergoing hemodialysis with new-onset AF than in those without AF, and it became insignificant when accounting for the competing risk of in-hospital death.