Atrial fibrillation in incident dialysis patients

Risk Factors of Ischemic Stroke and Subsequent Outcome in Patients Receiving Hemodialysis

Background and Purpose—

End-stage renal disease (ESRD) requiring hemodialysis carries up to a 10-fold greater risk of stroke than normal renal function. Knowledge on risk factors and management strategies derived from the general population may not be applicable to those with ESRD. We studied a large ESRD population to identify risk factors and outcomes for stroke.

Methods—

All adult patients receiving hemodialysis for ESRD from January 1, 2007, to December 31, 2012, were extracted from the electronic patient record. Variables associated with stroke were identified by survival analysis; demographic, clinical, imaging, and dialysis-related variables were assessed, and case-fatality was determined. Follow-up was until December 31, 2013.

Results—

A total of 1382 patients were identified (mean age, 60.5 years; 58.5% men). The prevalence of atrial fibrillation was 21.2%, and 59.4% were incident hemodialysis patients. One hundred and sixty patients (11.6%) experienced a stroke during 3471 patient-years of follow-up (95% ischemic). Stroke incidence was 41.5/1000 patient-years in prevalent and 50.1/1000 patient-years in incident hemodialysis patients. Factors associated with stroke on regression analysis were prior stroke, diabetes mellitus, and age at starting renal replacement therapy. Atrial fibrillation was not significantly associated with stroke, and warfarin did not affect stroke risk in warfarin-treated patients. Fatality was 18.8% at 7 days, 26.9% at 28 days, and 56.3% at 365 days after stroke.

Conclusions—

Incidence of stroke is high in patients with ESRD on hemodialysis with high case-fatality. Incident hemodialysis patients had the highest stroke incidence. Many, but not all, important risk factors commonly associated with stroke in the general population were not associated with stroke in patients receiving hemodialysis.

Valvular calcifications at the start of dialysis predict the onset of cardiovascular events in the course of follow-up

OBJECTIVE

To analyse the presence of VC at the start of dialysis and its relationship with events and/or death from cardiovascular causes in the course of follow-up.

METHODS

In the study, we included patients who started dialysis between November 2003 and September 2007. In the first month of treatment, we assessed the presence of VC by Doppler echocardiography, along with demographic factors and risk factors for cardiovascular disease, coronary artery disease, stroke, atrial fibrillation (AF), and cardiac dimensional and functional electrocardiographic and echocardiographic parameters. The biochemistry values assessed were: haemoglobin, calcium/phosphorous/iPTH metabolism, cholesterol and fractions, triglycerides, troponin I, albumin, CRP and glycosylated haemoglobin. We analysed the association between VC and the presence of myocardial infarction (MI), stroke and/or death from cardiovascular causes up to transplantation, death or the end of the study (December 2012).

RESULTS

Of 256 enrolled patients (83% haemodialysis, 17% peritoneal dialysis), 128 (50%) had VC (mitral: 39, aortic: 20, both: 69). In the multivariate analysis, VC was associated with older age (OR: 1.110; 95% CI: 1.073-1.148; p = 0.000) and lower albumin levels (OR: 0.29; 95% CI: 0.14-0.61; p = 0.001). In a follow-up lasting 42.1 ± 30.2 months (898.1 patient-years), 68 patients suffered MI, stroke and/or died from cardiovascular causes. In the Cox regression analysis, older age (HR: 1.028; 95% CI: 1.002-1.055; p = 0.037), coronary artery disease and/or stroke (HR: 1.979; 95% CI: 1.111-3.527; p = 0.021), AF (HR: 2.474; 95% CI: 1.331-4.602; p = 0.004), and the presence of VC at the start of dialysis (HR: 1.996; 95% CI: 1.077-3.700; p = 0.028) were the predictor variables for the occurrence of the analysed events.

CONCLUSIONS

The prevalence of VC at the start of dialysis is high and its presence predicts the occurrence of events and/or cardiovascular death in the course of follow-up.

Incidence and risk factors for new-onset atrial fibrillation among patients with end-stage renal disease undergoing renal replacement therapy

Atrial fibrillation (AF) is prevalent in end-stage renal disease (ESRD) patients and negatively impacts patient outcomes. We explored the incidence and risk factors for new-onset AF among patients with ESRD undergoing renal replacement therapy, without a prior history of AF, retrieved from Taiwan's National Health Insurance Research Database (NHIRD). For each of 134,901 patients with ESRD, one age- and gender-matched control and one similarly matched patient with chronic kidney disease (CKD), a total of 404,703 patients, were selected from the NHIRD. The study endpoint was the occurrence of new-onset AF and patients were followed an average of 5.1 years. The incidence rates of AF were 12.1, 7.3, and 5.0 per 1000 person-years for ESRD, CKD, and control patients, respectively. Among patients with ESRD, age, hypertension, heart failure, coronary artery disease, peripheral arterial occlusive disease, and chronic obstructive pulmonary disease were significant risk factors for new-onset AF. Thus, patients with ESRD had a significantly higher risk of new-onset AF. The presence of multiple risk factors was associated with a higher possibility of AF occurrence.

Sudden cardiac death in end stage renal disease: unlocking the mystery

Sudden cardiac death (SCD) is a major cause of concern in end stage renal disease (ESRD), contributing to 70% of cardiovascular mortality and 27% of all-cause mortality in dialysis patients. Yet its mechanisms and pathogenesis remain largely obscure. This review discusses the potential reasons for an exaggerated risk of SCD in ESRD populations taking into account recent studies and registry data and additionally explores the reasons for the reported recent decline in SCD. The types of arrhythmias typical of the hemodialysis population are yet to be fully characterised and in this paper, we introduce an ongoing implantable loop recorder (ILR) based study in hemodialysis patients--CRASH ILR (Cardio Renal Arrhythmia Study in Haemodialysis patients using Implantable Loop Recorders). The findings of this study will hopefully guide the design and implementation of larger ILR based studies before undertaking larger scale interventional therapeutic trials in this high risk population.

Vitamin K antagonists: beyond bleeding

Warfarin is the most widely used oral anticoagulant in clinical use today. Indications range from prosthetic valve replacement to recurrent thromboembolic events due to antiphospholipid syndrome. In hemodialysis (HD) patients, warfarin use is even more frequent than in the nonrenal population due to increased cardiovascular comorbidities. The use of warfarin in dialysis patients with atrial fibrillation requires particular caution because side effects may outweigh the assumed benefit of reduced stroke rates. Besides increased bleeding risk, coumarins exert side effects which are not in the focus of clinical routine, yet they deserve special consideration in dialysis patients and should influence the decision of whether or not to prescribe vitamin K antagonists in cases lacking clear guidelines. Issues to be taken into consideration in HD patients are the induction or acceleration of cardiovascular calcifications, a 10-fold increased risk of calciphylaxis and problems related to maintaining a target INR range. New anticoagulants like direct thrombin inhibitors are promising but have not yet been approved for ESRD patients. Here, we summarize the nontraditional side effects of coumarins and give recommendations about the use of vitamin K antagonists in ESRD patients.

Evidence for the prevention and treatment of stroke in dialysis patients

The risks of both ischemic and hemorrhagic stroke are particularly high in dialysis patients of any age and outcomes are poor. It is therefore important to identify strategies that safely minimize stroke risk in this population. Observational studies have been unable to clarify the relative importance of traditional stroke risk factors such as blood pressure and cholesterol in those on dialysis, and are affected by biases that usually make them an inappropriate source of data on which to base therapeutic decisions. Well-conducted randomized trials are not susceptible to such biases and can reliably investigate the causal nature of the association between a potential risk factor and the outcome of interest. However, dialysis patients have been under-represented in the cardiovascular trials which have proven net benefit of commonly used preventative treatments (e.g., antihypertensive treatments, low-dose aspirin, carotid revascularization, and thromboprophylaxis for atrial fibrillation), and there remains uncertainty about safety and efficacy of many of these treatments in this high-risk population. Moreover, the efficacy of renal-specific therapies that might reduce cardiovascular risk, such as modulators of mineral and bone disorder, online hemodiafiltration, and daily (nocturnal) hemodialysis, have not been tested in adequately powered trials. Recent trials have also demonstrated how widespread current practices could be causing stroke. Therefore, it is important that reliable information on the prevention and treatment of stroke (and other cardiovascular disease) in dialysis patients is generated by performing large-scale randomized trials of many current and future treatments.

Renal function, attributes and coagulation treatment in atrial fibrillation (R-FACT Study): retrospective, observational, longitudinal cohort study of renal function and antithrombotic treatment patterns in atrial fibrillation patients with documented eGFR in real-world clinical practices in Germany

AIMS

This retrospective, observational, longitudinal study aimed to document the distribution, changes in renal function [measured by estimated glomerular filtration (eGFR)] and antithrombotic treatment pattern in atrial fibrillation (AF) patients in real-world settings managed by general practitioners in Germany.

METHODS AND RESULTS

Data were extracted from the German Longitudinal Patient Database. A total of 15,900 patients with AF were identified. Among 1660 having eGFR available at baseline, 3.4% had severely impaired eGFR, 9.7% and 25.6% had moderate severe decrease and moderate decrease in eGFR, respectively, and 61.3% had mildly decreased/normal eGFR. Patients with moderately and severely decreased eGFR tended to be older. The proportion of patients with a CHADS2 score ≥ 2 was 92.9% in those with severely decreased eGFR, and 87.0% and 79.1% in those with moderately severe and moderately decreased eGFR. During follow up, 52.1% of patients with severely decreased eGFR, and 26.3% to 23.7% of patients with moderately decreased eGFR were not treated by antithrombotic. When comparing baseline with follow-up eGFR, 55.0% of patients showed decreased eGFR. Age, diabetes, dyslipidaemia and history of myocardial infarction were identified as significant predictors for renal function deterioration based on results from multivariate Cox regression model.

CONCLUSIONS

Moderate-to-severe renal dysfunction is prevalent (~38%) in German AF patients with documented eGFR managed in actual clinical practices. The risk of stroke, as measured by the CHADS2 score, was associated with decreased renal function. Treatment with anticoagulation therapies decreased with decreasing renal function, despite increasing risk of stroke. Anticoagulation treatments remain suboptimal during the 12-month follow up in patients with moderate or severe renal impairment.

Sudden death in incident dialysis patients

BACKGROUND

Sudden death (SD) constitutes one of the principal causes of death and is an important problem in healthcare provision. Cardiovascular diseases have a high prevalence in dialysis patients and constitute the principal cause of death. We sought to analyze retrospectively the incidence of SD in patients commencing dialysis and the factors related to its presence.

METHODS

We evaluated all the patients who began dialysis in our center between 1/11/2003 and 15/9/2007, and who were followed up until death, transplant, or study completion on 31/12/2012. We determined the presence of SD according to the following criteria: SD at 24 h (SD 24H): unexpected death occurring in the 24 h following the start of symptoms, or when the patient was found dead and had been seen alive 24 h earlier; SD at 1 h (SD 1H): death witnessed as occurring in the first hour following the start of symptoms.

RESULTS

We evaluated 285 patients, mean age 65.67 ± 15.7 years. In a follow-up of 39.9 ± 34.2 months (947.6 patient-years of follow-up) 168 died (59%), 28 (10%) patients presented SD 24H (2.9/100 patient-years), and 16 (6%) patients presented SD 1H (1.7/100 patient-years). In the multivariate analysis, having had a myocardial infarction or having had electrocardiographic abnormalities (Q wave, negative T wave, subendocardial lesion or QRS >120 ms) were the principal independent predictors of SD 24H (OR 7.83; 95% CI 2.20-27.86; p = 0.001) and of SD 1H (OR 13.43; 95% CI 1.56-115.42; p = 0.018).

CONCLUSIONS

SD on dialysis is very frequent. Two groups can be identified easily, with risk profiles clearly differentiated.

A look at the upper heart chamber: the left atrium in chronic kidney disease

Altered left ventricular (LV) mass and function are classical hallmarks of cardiomyopathy in chronic kidney disease (CKD). The left atrium (LA), a heart chamber exquisitely sensitive to volume overload and diastolic function, is an independent predictor of death and adverse cardiovascular (CV) events in high-risk patients such as those with hypertension and/or with heart failure. In this review we focus on the relationship of LA size with LV diastolic function, and the association between LA enlargement and CV and renal outcomes in patients with CKD, including patients with end-stage renal disease. Increased LA size emerges as a powerful predictor of mortality and major adverse CV events in both end-stage and early CKD, and some studies also show a close association between enlarged LA and renal disease progression. Secondary analyses of clinical trials suggest that the LA has the potential to be elected as a surrogate end point in CKD patients but the issue remains to be tested in specifically designed clinical studies.

Anti-coagulation, anti-platelets or no therapy in haemodialysis patients with atrial fibrillation: A decision analysis

BACKGROUND

Optimal treatment of atrial fibrillation (AF) in the haemodialysis population is uncertain due to the exclusion of this group from randomized trials. The risk-benefit profile for anticoagulation and anti-platelet therapy in haemodialysis differs from the general population due to platelet dysfunction from uraemia, altered pharmacokinetics and increased falls risk.

METHODS

This decision analysis used a Markov-state transition model that took a patient perspective over a 5 year timeframe. The Markov model compared life-years gained and quality-adjusted life-years gained (QALY) for three AF treatment strategies: warfarin, aspirin and no treatment. The base case was a 70-year-old man on haemodialysis with non-valvular AF.

RESULTS

In the base case, the total health outcomes in life-years and QALY were 2.37 and 1.47 respectively for warfarin, 2.38 and 1.61 respectively for aspirin, and 2.39 and 1.61 respectively for no treatment. Thus, warfarin led to 0.14 fewer QALY or 1.7 fewer months of life lived in full health, compared with either aspirin or no therapy. The finding that warfarin generated the lowest expected QALY was robust to one-way, two-way and probabilistic sensitivity analyses.

CONCLUSIONS

Our results suggest that warfarin should not be the default choice for older haemodialysis patients with non-valvular AF as it provides the fewest QALY compared with aspirin or no therapy.

Management of atrial fibrillation in chronic kidney disease: double trouble

Chronic kidney disease (CKD) has a very well-established link with cardiovascular disease. Below stage 3 CKD (glomerular filtration rate <60 mL/min), there is a progressive increase in both total mortality and cardiovascular-specific mortality as kidney function declines; indeed, it is more likely for a patient with CKD stage 3 to die of cardiovascular disease than to progress to CKD stage 4 and beyond. Arrhythmia is particularly common in patients with CKD. Depending on the study and measurement used, the prevalence of patients with CKD with chronic atrial fibrillation (AF) is quoted at 7% to 18%, rising to 12% to 25% for those older than 70 years. These rates are up to 2 to 3 times higher than in the general population. Of all patients with AF, 10% to 15% will have CKD. However, not all standard rate and rhythm methods are suitable for this population and those that are tend to be less effective. Meanwhile, anticoagulation has long been a thorny subject, with much conflicting evidence around the balance between bleeding and stroke risk. To help clarify this, we first highlight the challenges of performing evidence-based medicine in the patient with renal disease, and then review recent and emerging research to suggest an approach to the management of patients with renal disease who have AF. We also review the potential role of the different new oral anticoagulant drugs in CKD.

Incidence of stroke before and after dialysis initiation in older patients

The incidence of stroke is substantially higher among hemodialysis patients than among patients with earlier stages of CKD, but to what extent the initiation of dialysis accelerates the risk for stroke is not well understood. In this cohort study, we analyzed data from incident hemodialysis and peritoneal dialysis patients in 2009 who were at least 67 years old and had Medicare as primary payer. We noted whether each of the 20,979 hemodialysis patients initiated dialysis as an outpatient (47%) or inpatient (53%). One year before initiation, the baseline stroke rate was 0.15%-0.20% of patients per month (ppm) for both outpatient and inpatient initiators. Among outpatient initiators, stroke rates began rising approximately 90 days before initiation, reached 0.5% ppm during the 30 days before initiation, and peaked at 0.7% ppm (8.4% per patient-year) during the 30 days after initiation. The pattern was similar among inpatient initiators, but the stroke rate peaked at 1.5% ppm (18% per patient-year). For both hemodialysis groups, stroke rates rapidly declined by 1-2 months after initiation, fluctuated, and stabilized at approximately twice the baseline rate by 1 year. Among the 620 peritoneal dialysis patients, stroke rates were slightly lower and variable, but approximately doubled after initiation. In conclusion, these data suggest that the process of initiating dialysis may cause strokes. Further studies should evaluate methods to mitigate the risk for stroke during this high-risk period.

Management of cardiovascular disease in patients with kidney disease

The burden of cardiovascular disease is high in patients with chronic kidney disease or end-stage renal disease. The presence of kidney dysfunction affects the cardiovascular system in multiple ways, including accelerated progression of atherosclerosis and valvular disease, the exacerbation of congestive heart failure, and the development of pericardial disease. This comorbidity results not only from the concordance of shared risk factors, but also from other issues specific to this population, such as systemic inflammation and vascular calcification. Furthermore, both the sensitivity and specificity of noninvasive testing modalities, and the efficacy of several pharmacotherapeutic strategies, are diminished in this population. The exclusion of patients with severe kidney disease from many clinical trials of cardiac interventions raises various therapeutic uncertainties, and kidney disease itself is likely to alter the underlying cardiovascular physiology. In this Review, we discuss aspects of the epidemiology, pathophysiology, and diagnosis of cardiovascular disease in patients with kidney disease, and propose specific, evidence-based recommendations for pharmacological and surgical treatment.

Sailing between Scylla and Charybdis: oral long-term anticoagulation in dialysis patients

End-stage renal disease (ESRD) patients exhibit an increased risk of bleeding compared with non-chronic kidney disease (CKD) patients due to uraemic platelet dysfunction, altered vessel architecture and other factors. This renders any long-term oral anticoagulation potentially difficult. While there is little doubt that ESRD patients with recurrent thromboembolism or a mechanical cardiac valve should receive vitamin K antagonists (coumarins), the use of coumarins in ESRD patients with atrial fibrillation is a matter of debate. In non-CKD patients, current guidelines strongly recommend the use of oral anticoagulants for stroke prophylaxis in atrial fibrillation if certain risk factors are present (CHA2DS2-VASc score). This recommendation is often extrapolated to patients with advanced CKD or ESRD but data supporting this practice are weak to absent. Besides an increased bleeding risk in ESRD patients, coumarins will also accelerate cardiovascular calcification and are potent risk factors for the development of calcific uraemic arteriolopathy (calciphylaxis). Novel coumarin alternatives such as direct thrombin inhibitors are promising but none is currently approved for use in ESRD patients. Whether interventional treatment strategies such as atrial appendage occlusion are safe and effective options in advanced CKD is also as yet unresolved. This review attempts to balance the potential risks and benefits of coumarin usage in ESRD patients and to give the best possible recommendations for everyday patient care.

Anticoagulation for atrial fibrillation in patients on dialysis: are the benefits worth the risks?

PURPOSE OF REVIEW

Atrial fibrillation is common among patients with end-stage renal disease undergoing hemodialysis. Although oral anticoagulation is recommended for stroke prevention in most patients with atrial fibrillation, limited evidence is available to guide treatment in hemodialysis patients with this arrhythmia. We summarize the available evidence on the epidemiology of atrial fibrillation in dialysis patients and review the data on the effectiveness of oral anticoagulation in this population.

RECENT FINDINGS

Atrial fibrillation is increasingly common in patients undergoing chronic hemodialysis, especially among older patients wherein one in six patients is diagnosed with this arrhythmia. Patients with atrial fibrillation experience double the mortality of otherwise similar patients without it. Few hemodialysis patients with atrial fibrillation receive oral anticoagulation, which is consistently associated with excess risks of hemorrhagic stroke. Observational studies did not detect a beneficial association of oral anticoagulation with the risk of ischemic stroke, with some studies describing higher risks of ischemic stroke among warfarin users. New therapeutic options including one oral direct thrombin inhibitor and two oral factor Xa inhibitors have become available, but were not tested in patients with advanced kidney disease.

SUMMARY

Atrial fibrillation is increasingly common in patients undergoing hemodialysis, yet little is known about the optimal management of these patients. The current evidence does not support net benefits from oral anticoagulation in the dialysis population.

Atrial fibrillation: the beat is faster than the answers

The prevalence of atrial fibrillation is much greater among persons with end-stage renal disease (ESRD) than among the general population. While significant advances have been made recently in the treatment of atrial fibrillation in the general population, we know very little about the treatment of atrial fibrillation among those with ESRD. This Commentary explores gaps in our knowledge of how to treat this vulnerable and sick population.

Atrial Fibrillation and Oral Anticoagulation in Chronic Kidney Disease

Due to several unfavorable epidemiological changes, chronic kidney disease (CKD) and treatment of its associated cardiovascular morbidity have become a worldwide problem. Thus, atrial fibrillation (AF) is the most common arrhythmia and frequently associated with renal impairment: prevalence for AF is up to 27% in long-term hemodialysis patients and in general more than 25% in all CKD patients 70 years and older. Thromboembolism and stroke are the major complications of AF. Two-year death rates for CKD patients after stroke range between 55% and 74%. Although treatment of AF in the general population is well defined, patients with CKD and AF are often undertreated due to lack of studies and guidelines. In this review recent data concerning incidence and prevalence of AF, stroke, and major bleedings in CKD patients are presented. Particular attention is paid to the available data about the different types of oral anticoagulation therapy with regard to CKD stage, including the new oral anticoagulant drugs dabigatran, rivaroxaban, and apixaban. Stratification algorithms for stroke risk in general, and individualized risk stratification for oral anticoagulation in CKD patients are discussed in detail.

The prevalence of and factors associated with chronic atrial fibrillation in Medicare/Medicaid-eligible dialysis patients

Atrial fibrillation is an important comorbidity with substantial therapeutic implications in dialysis patients but its prevalence varies in different studies. We used a database that includes patients in the United States on hemodialysis who were eligible for government assistance with prescription drugs. We then used ICD-9 codes from billing claims in this database to identify patients with chronic atrial fibrillation. Multivariable logistic regression was used to determine adjusted prevalence odds ratios for associated factors. Of 63,884 individuals, the prevalence of chronic atrial fibrillation was 7%. The factors of age over 60 years, male, Caucasian, body mass index over 25 kg/m(2), coronary artery disease, and heart failure were all significantly associated with chronic atrial fibrillation. Prevalence rates, particularly in younger patients, were far higher than those reported in an age group-matched nondialysis population. Thus, given its clinical impact, future efforts are needed to examine risk factors for adverse outcomes in chronic atrial fibrillation, and to identify appropriate management strategies for this disorder, as well as opportunities for quality improvement in this vulnerable population.

Clinical characteristics and cardiovascular outcomes of hemodialysis patients with atrial fibrillation: a prospective follow-up study

BACKGROUND/AIMS

Among the cardiovascular complications in dialysis patients, atrial fibrillation (AF) is the most common arrhythmia. The purpose of this study was to clarify the characteristics and mortality of hemodialysis patients with AF, which are not completely elucidated.

METHODS

The prevalence of AF in patients undergoing hemodialysis in our institutions was assessed. Patients with AF (AF group) and without AF (control group) were included in this study. Patients in the control group were matched for several important clinical risk factors. For further analysis, AF patients were divided into two groups on the basis of the type of AF (chronic AF (CAF) and paroxysmal AF (PAF) groups). These patients were evaluated for their clinical characteristics, laboratory data and echocardiographic parameters and prospectively followed up for 48 months.

RESULTS

Among 328 study patients, 30 had AF (9.1%). Left atrial diameter (LAD) and the left ventricular mass index were significantly greater in the AF group than in the control group. Furthermore, cardiovascular and all-cause mortality and cumulative incidence of cardiovascular events were significantly higher in the AF group than in the control group, and tended to be higher in the CAF group.

CONCLUSIONS

Our findings demonstrated that the prevalence of AF as 9.1% in hemodialysis patients, and that AF, especially CAF, were associated with high mortality.

Traditional and nontraditional risk factors as predictors of cerebrovascular events in patients with end stage renal disease

OBJECTIVES AND METHODS

End stage renal disease (ESRD) patients exhibit a higher risk of cerebrovascular events as compared with the general population. In 283 ESRD patients followed up for 10 years, we investigated the long-term predictive value for stroke and transient ischemic attacks of traditional and nontraditional risk factors. Data analysis was performed by a modified Cox regression analysis for repeated events and by a competing risks analysis.

RESULTS

During the follow-up, 61 cerebrovascular events occurred in 47 patients. On univariate Cox analysis, the risk of cerebrovascular outcomes was directly related to age, smoking, diabetes, BMI, systolic and pulse pressures, triglycerides, hemoglobin, history of stroke/transient ischemic attacks, arrhythmia and left ventricular mass index. Nontraditional risk factors in ESRD such as norepinephrine, homocysteine, interleukin-6 and asymmetric dimethylarginine failed to predict these events. In a multivariate Cox model for repeated events only smoking [hazard ratio: 2.45, 95% confidence interval (CI): 1.29-4.65], age (hazard ratio: 1.05, 95% CI: 1.01-1.08), hemoglobin (hazard ratio: 1.28, 95% CI 1.06-1.54), triglycerides (hazard ratio: 1.04, 95% CI 1.01-1.08), pulse pressure (hazard ratio: 1.53, 95% CI 1.01-2.23) and left ventricular mass index (hazard ratio: 1.02, 95% CI 1.01-1.04) maintained an independent relationship with cerebrovascular events. The direct link between hemoglobin and cerebrovascular events was significantly stronger (P < 0.05) than that of the same variable and death.

CONCLUSION

The risk of stroke in ESRD depends mainly on traditional risk factors, high hemoglobin and left ventricular hypertrophy. Multiple interventions aimed to reduce arterial stiffness, left ventricular mass and smoking as well as to maintain hemoglobin within the recommended therapeutic range may have beneficial effects on the risk of cerebrovascular events in ESRD patients.

The increasing prevalence of atrial fibrillation among hemodialysis patients

A half million Americans have ESRD, which puts them at high risk for cardiovascular disease and poor outcomes. Little is known about the epidemiology of atrial fibrillation among patients with ESRD. We analyzed data from annual cohorts (1992 to 2006) of prevalent hemodialysis patients from the United States Renal Data System. In each cohort, we searched 1 year of medical claims for relevant diagnosis codes to determine the prevalence of atrial fibrillation. Among 2.5 million patient observations, 7.7% had atrial fibrillation, with the prevalence increasing 3-fold from 3.5% (1992) to 10.7% (2006). The number of affected patients increased from 3620 to 23,893 (6.6-fold) during this period. Older age, male gender, and several comorbid conditions were associated with increased risk for atrial fibrillation. Compared with otherwise similar Caucasians, the prevalence of atrial fibrillation rates was substantially lower for blacks, Asians, and Native Americans. One-year mortality was twice as high among hemodialysis patients with atrial fibrillation compared with those without (39% versus 19%), and this increased risk was constant during the 15 years of the study. In conclusion, the prevalence of diagnosed atrial fibrillation among patients receiving hemodialysis in the United States is increasing, varies by race, and remains associated with substantially increased mortality. Identifying potentially modifiable risk factors for incident atrial fibrillation requires further investigation.

Warfarin in haemodialysis patients with atrial fibrillation: what benefit?

Warfarin is commonly used to prevent stroke in patients with atrial fibrillation; however, patients on haemodialysis may not derive the same benefit from warfarin as the general population. There are no randomized controlled studies in dialysis patients which demonstrate the efficacy of warfarin in preventing stroke. In fact, warfarin places the dialysis patient at increased risk for haemorrhagic stroke and possibly ischaemic stroke. Additionally, warfarin increases the risk of major bleeding and has been associated with vascular calcification. Routine use of warfarin in dialysis for stroke prevention should be discouraged, and therapy should only be reserved for dialysis patients at high risk for thrombo-embolic stroke and carefully monitored if implemented.

Ischaemic stroke in incident dialysis patients

BACKGROUND

Despite the high frequency of cardiovascular disease among the population on dialysis, there are few studies on ischaemic stroke and associated factors. The objective of the present study is to assess the prevalence of ischaemic stroke at the start of dialysis, its incidence in the course of follow-up and possible factors associated in its presentation.

METHODS

All patients in our dialysis programme between 1 January 1999 and 31 December 2005 were included in the study and followed up until death, transplant, transfer out of our catchment area, or conclusion of the study on 31 December 2008. Factors analysed were age, gender, smoking habit, diabetes, hypertension, previous ischaemic stroke, ischaemic coronary disease, peripheral vascular disease and atrial fibrillation. Other factors measured in the first month of dialysis were haematocrit, urea, creatinine, lipids, calcium, phosphorus, parathyroid hormone and albumin.

RESULTS

Of 449 patients included in the study (age 64.4 ± 16 years), 30 commenced dialysis having had previous stroke (prevalence 6.7%). In a follow-up of 38.77 ± 29 months, 34 patients presented with one or more strokes; an incidence of 2.41/100 patient-years. Greater age [odds ratio (OR): 1.05; 95% confidence interval (CI): 1.01-1.09; P = 0.007], diabetes (OR: 2.29; 95% CI: 1.15-4.55; P = 0.018) and presence of atrial fibrillation (OR: 3.11; 95% CI: 1.53-6.32; P = 0.002) were independent predictors of stroke occurrence. Conclusions. The prevalence of ischaemic stroke is high at the commencement of dialysis, and its incidence is elevated in the course of follow-up. As with the general population, atrial fibrillation is an important factor predictive of ischaemic stroke, and as such, the clinical implication is that prophylactic anti-coagulation therapy needs to be considered for these individuals.

Atrial fibrillation in end-stage renal disease: an emerging problem

End-stage renal disease is associated with considerable cardiovascular morbidity and mortality. Atrial fibrillation (AF) is prevalent among dialysis patients and adversely affects the clinical outcome. Vazquez et al. report an increased prevalence and incidence of AF in patients who commence dialysis, and an independent association between arrhythmia and mortality risk. Moreover, they examined clinical and laboratory parameters associated with AF. This population study may fuel research aiming at the development of novel preventive and treatment strategies.