Comparison of prognostic value of atrial fibrillation versus sinus rhythm in patients on long-term hemodialysis

Current status of stroke in hemodialysis patients on a remote island

OBJECTIVES

Hemodialysis patients have a higher incidence of stroke than healthy individuals. Hemodialysis patients living on remote islands are subject to additional distance and transportation difficulties. Therefore, we aimed to study the association between stroke and hemodialysis in patients living on remote islands.

MATERIALS AND METHODS

We conducted a retrospective cohort study based on the medical records of maintenance hemodialysis patients in Shinkamigoto-Cho, Nagasaki, Japan, between June 1, 2005, and June 31, 2022. The clinical characteristics, probability of hemorrhagic stroke, acute ischemic stroke-free rate, and survival probability with or without a history of anticoagulant/antiplatelet use were evaluated. The survival probability among the hemorrhagic stroke, acute ischemic stroke, and non-stroke groups was also evaluated.

RESULTS

This study involved 142 patients. Nine patients (6.3%) had intracerebral hemorrhage, one (0.7%) had subarachnoid hemorrhage, eight (5.6%) had acute ischemic stroke, and 124 (87.3%) had no stroke. The number of patients with severe disabilities (modified Rankin Scale 5/6) was significantly higher in the hemorrhagic stroke group. The probability of hemorrhagic stroke and acute ischemic stroke-free rate, or survival probability with or without a history of anticoagulant/antiplatelet use, were not significantly different. The acute ischemic stroke group was not associated with a lower survival probability than the other groups. The hemorrhagic stroke group had a significantly lower survival probability than the acute ischemic stroke group.

CONCLUSIONS

This is the first study to report the status of stroke in hemodialysis patients living on remote islands, thus providing valuable information for improved stroke management in such patients.

Improvement in Quality of Life via Catheter Ablation for Atrial Fibrillation in Patients Undergoing Hemodialysis Therapy

Background

Methods

Results

Conclusions

Non-vitamin K antagonist oral anticoagulants in atrial fibrillation patients with advanced chronic kidney and liver diseases

Advanced chronic kidney disease (CKD) or chronic liver disease (CLD) is frequent in patients with atrial fibrillation (AF) because of their common risk factors. Chronic kidney disease and CLD superimposed on AF are associated with increased risks of thrombosis and bleeding, which further complicates the use of oral anticoagulants (OACs). Because currently approved non-vitamin K antagonist oral anticoagulants (NOACs) undergo certain degrees of metabolism and clearance in the liver and kidney, increased exposure to medications and risk of bleeding are major concerns with the use of NOACs in patients with advanced CKD and CLD. Besides, these patients were mostly excluded from landmark trials of NOACs and related cohort studies are also limited. Therefore, the optimal strategy for the use of NOACs in this population remains unclear. This review would go through current evidence regarding the safety and efficacy of NOACs in AF patients with advanced CKD and CLD and provide a comprehensive discussion for clinical practices.

Comparison between cryoballoon ablation and radiofrequency catheter ablation for atrial fibrillation in patients on hemodialysis

Background

Difficulties are often encountered while controlling atrial fibrillation (AF), especially in hemodialysis (HD) patients. Previous data revealed that cryoballoon ablation (CBA) for treating paroxysmal atrial fibrillation (PAF) was not inferior to radiofrequency ablation (RFA); however, HD patients were excluded in this prior trial. Thus, the efficacy of CBA for HD patients is still unknown.

Methods

This retrospective study analyzed HD patients who underwent catheter ablation (CA) for AF from August 2011 to June 2019. Patients who received CBA (CBA group) and those who received RFA (RFA group) were compared. The primary endpoint was defined as freedom from a composite outcome (a documented recurrence of any atrial tachyarrhythmia or a prescription of antiarrhythmic drugs) at one year after CA.

Results

The RFA and CBA groups were composed of 21 and 23 patients, respectively. Freedom from a composite outcome was 58.4% in the RFA group and 68.2% in the CBA group (Log-rank: p = 0.571).

Conclusion

Our results suggest that patients on HD with AF who were treated with CBA tended to have better outcomes than patients treated with RFA. Therefore, CBA could be a suitable ablation method for HD patients.

The relation between epicardial fat tissue thickness and atrial fibrillation ın hemodialysis patients

The prevalence of arrhythmia has increased in hemodialysis (HD) patients and the most frequent is atrial fibrillation (AF). It was reported that the amount of epicardial fat tissue (EFT) in the population without renal disease is closely related to AF. In the present study of ours, the relation between EFT thickness and AF was examined in HD patients. A total of 79 patients who underwent HD for periods longer than 3 months were included in the study. The mean age of the patients was 53.6 ± 15.2 years and 50.6% were male. The mean EFT thicknesses were measured as 7.2 ± 2.3 mm (3-12). A positive correlation was found between the EFT thickness and age, C-reactive protein, and left ventricle rear wall thickness. AF was found in 18 (22.8%) patients in the Holter ECG examination. When the group with AF was compared with the non-AF group; although the mean HD duration of the group with AF was longer, there were no significant differences in terms of epicardial adipose tissue thickness and other parameters. In the present study, no relations were found between EFT thickness and AF frequency in HD patients. Further studies with a larger number of the patient population are needed in this regard.

Epidemiology of Atrial Fibrillation in the 21st Century: Novel Methods and New Insights

Accompanying the aging of populations worldwide, and increased survival with chronic diseases, the incidence and prevalence of atrial fibrillation (AF) are rising, justifying the term global epidemic. This multifactorial arrhythmia is intertwined with common concomitant cardiovascular diseases, which share classical cardiovascular risk factors. Targeted prevention programs are largely missing. Prevention needs to start at an early age with primordial interventions at the population level. The public health dimension of AF motivates research in modifiable AF risk factors and improved precision in AF prediction and management. In this review, we summarize current knowledge in an attempt to untangle these multifaceted associations from an epidemiological perspective. We discuss disease trends, preventive opportunities offered by underlying risk factors and concomitant disorders, current developments in diagnosis and risk prediction, and prognostic implications of AF and its complications. Finally, we review current technological (eg, eHealth) and methodological (artificial intelligence) advances and their relevance for future prevention and disease management.

Apixaban Versus Warfarin in Patients With Atrial Fibrillation and Advanced Chronic Kidney Disease

Background:

Compared with the general population, patients with advanced chronic kidney disease have a >10-fold higher burden of atrial fibrillation. Limited data are available guiding the use of nonvitamin K antagonist oral anticoagulants in this population.

Methods:

We compared the safety of apixaban with warfarin in 269 patients with atrial fibrillation and advanced chronic kidney disease (defined as creatinine clearance [CrCl] 25 to 30 mL/min) enrolled in the ARISTOTLE trial (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation). Cox proportional models were used to estimate hazard ratios for major bleeding and major or clinically relevant nonmajor bleeding. We characterized the pharmacokinetic profile of apixaban by assessing differences in exposure using nonlinear mixed effects models.

Results:

Among patients with CrCl 25 to 30 mL/min, apixaban caused less major bleeding (hazard ratio, 0.34 [95% CI, 0.14–0.80]) and major or clinically relevant nonmajor bleeding (hazard ratio, 0.35 [95% CI, 0.17–0.72]) compared with warfarin. Patients with CrCl 25 to 30 mL/min randomized to apixaban demonstrated a trend toward lower rates of major bleeding when compared with those with CrCl >30 mL/min ( P interaction=0.08) and major or clinically relevant nonmajor bleeding ( P interaction=0.05). Median daily steady-state areas under the curve for apixaban 5 mg twice daily were 5512 ng/(mL·h) and 3406 ng/(mL·h) for patients with CrCl 25 to 30 mL/min or >30 mL/min, respectively. For apixaban 2.5 mg twice daily, the median exposure was 2780 ng/(mL·h) for patients with CrCl 25 to 30 mL/min. The area under the curve values for patients with CrCl 25 to 30 mL/min fell within the ranges demonstrated for patients with CrCl >30 mL/min.

Conclusions:

Among patients with atrial fibrillation and CrCl 25 to 30 mL/min, apixaban caused less bleeding than warfarin, with even greater reductions in bleeding than in patients with CrCl >30 mL/min. We observed substantial overlap in the range of exposure to apixaban 5 mg twice daily for patients with or without advanced chronic kidney disease, supporting conventional dosing in patients with CrCl 25 to 30 mL/min. Randomized, controlled studies evaluating the safety and efficacy of apixaban are urgently needed in patients with advanced chronic kidney disease, including those receiving dialysis.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT00412984.

Stroke Prophylaxis in Patients with Atrial Fibrillation and End-Stage Renal Disease

Atrial fibrillation (AF) is an important comorbidity in patients with end-stage renal disease (ESRD) undergoing dialysis that portends increased health care utilization, morbidity, and mortality in this already high-risk population. Patients with ESRD have a particularly high stroke risk, which is further compounded by AF. However, the role of anticoagulation for stroke prophylaxis in ESRD and AF is debated. The ESRD population presents a unique challenge because of the combination of elevated stroke and bleeding risks. Warfarin has been traditionally used in this population, but it is associated with significant risks of minor and major bleeding, particularly intracranial, thus leading many clinicians to forgo anticoagulation altogether. When anticoagulation is prescribed, rates of adherence and persistence are poor, leaving many patients untreated. The direct oral anticoagulants (DOACs) may offer an alternative to warfarin in ESRD patients, but these agents have not been extensively studied in this population and uncertainties regarding comparative effectiveness (versus warfarin, each other, and no treatment) remain. In this review, we discuss the current evidence on the risk and benefits of anticoagulants in this challenging population and comparisons between warfarin and DOACs, and review future directions including options for non-pharmacologic stroke prevention.

Atrial Fibrillation in Middle Eastern Arabs and South Asians: Summary of Published Articles in the Arabian Gulf

Seven studies are summarized herein focusing on different aspects of Atrial fibrillation (AF) in two unique ethnicities for which there is very limited literature published before; Middle Eastern Arabs and South Asians, using data from a national registry of cardiovascular diseases in Qatar over a 20-years period (1991-2010). These studies shed light upon important aspects of AF presentations and outcomes in these two ethnicities, thereby enriching the world literature on AF. In the process, several novel observations were reported and new questions were raised that warrant further investigations.

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.

Acute kidney injury is linked to higher mortality in elderly hospitalized patients with non-valvular atrial fibrillation

AIM

Renal insufficiency is associated with medical complications in patients with non-valvular atrial fibrillation (NVAF). However, data for elderly patients are scarce. Thus, the main objectives of the present study were to analyze the characteristics of elderly patients with NVAF and acute or chronic renal disease, describe their management in real-life conditions, and detect factors associated with complications.

METHODS

The NONAVASC registry includes patients > 75 years with NVAF, hospitalized by any cause in 64 Spanish Internal Medicine departments. Patients were categorized into acute kidney injury (AKI), chronic kidney disease (CKD) or preserved renal function (PRF). All variables associated with in-hospital mortality with P < 0.10 in univariate analysis were included to develop a multivariate logistic-regression model.

RESULTS

The study included 804 patients (53.9% women), 352 (43.8%) of whom met diagnostic criteria for CKD. AKI was detected in 119 (14.8%) patients. AKI was associated with greater length of stay, higher mortality and an increased rate of patient transfer to nursing homes. After logistic-regression analysis, we found an association between mortality and AKI (OR 2.4, 95% CI 1.03-5.53; P = 0.045). The increase in creatinine values (OR 1.8, 95% CI 1.19-2.73; P = 0.005) and the decrease in albumin values (OR 2.0, 95% CI 1.05-3.73; P = 0.033) were also linked to mortality.

CONCLUSIONS

Our study shows the relationship between AKI and creatinine value increase and a higher mortality in elderly patients with NVAF. In light of our findings, the detection of renal function impairment in these patients should alert physicians and consider them as high-risk patients.

Atrial fibrillation in dialysis patients: is there a place for non-vitamin K antagonist oral anticoagulants?

Atrial fibrillation (AF) occurs approximately in 3% of general population, with greater prevalence in elderly. Non-vitamin K-dependent oral anticoagulant agents (NOACs) according to the current European guidelines are recommended for patients with AF at high risk for stroke as a first-choice treatment. NOACs are not inferior to warfarin or some of them are better than warfarin in reducing the rate of ischemic stroke. Moreover, they significantly reduce the rate of intracranial hemorrhages, major bleedings, and mortality compared with warfarin. Nevertheless according to ESC guidelines, NOACs are not recommended in patients with creatinine clearance < 30 mL/min. Observational studies provide contradictive data. Only few new trials are ongoing. Therefore, it is not clear if NOACs should be in the future prescribed to patients with advanced CKD and those on dialysis. Moreover, the risk of stroke and bleeding is much higher in such population than in patients without end-stage renal disease (ESRD). The authors provide data on pros and cons of use of NOACs in ESRD patients with AF.

Changes in glomerular filtration rate and outcomes in patients with atrial fibrillation

BACKGROUND

Patients with kidney disease are more likely to develop atrial fibrillation (AF) than individuals with normal renal function, and more likely to suffer ischemic stroke (IS)/thromboembolism (TE). We investigated the relationship of kidney function evolution to IS/TE, mortality and bleeding in AF patients.

METHODS

In a cohort of 8962 AF patients, 2653 had serum creatinine data, with 10894 patient-years of follow-up. Patients were stratified into quartiles of estimated glomerular filtration rate (eGFR) evolution (in mL/min per 1.73 m²/year).

RESULTS

Rates of events (IS/TE, bleeding, mortality) increased with worsening eGFR by quartiles. The risk of events was particularly increased when patients in the 4th quartile were compared to others. Renal impairment per se was not an independent predictor of IS/TE but was an independent predictor of bleeding, whilst eGFR worsening was an independent predictor both for IS/TE (Hazard Ratio [HR] 1.573, 95%CI 1.160-2.134 for patients in the last quartile) and for bleeding events (HR 1.543, 95%CI 1.157-2.004). Worsening eGFR did not improve the predictive ability of the CHA₂DS₂VASc and HAS-BLED scores for identifying a higher risk of IS/TE or bleeding events, respectively. When the benefit of IS reduction was balanced against the increased risk of bleeding events, the net clinical benefit was positive in favor of OAC use (vs non-use) in patients with worsening eGFR.

CONCLUSIONS

Rates of IS/TE, mortality and bleeding increased with worsening eGFR >4.81 mL/min per 1.73 m². Worsening eGFR was an independent predictor of IS/TE and of bleeding, and a better predictor of IS/TE than renal impairment in AF.

Does chronic kidney disease improve the predictive value of the CHADS2 and CHA2DS2-VASc stroke stratification risk scores for atrial fibrillation?

Chronic Kidney Disease (CKD) constitutes an adverse risk factor in chronic anticoagulated atrial fibrillation (AF) patients, being related to adverse cardiovascular events, mortality and major bleeds. It is unclear if CKD adds independent prognostic information to stroke risk stratification schemes, as the risk factor components of the CHADS2 and CHA2DS2-VASc scores are themselves related to renal dysfunction. The aim of our study was to determine if CKD independently improves the predictive value of the CHADS2 and CHA2DS2-VASc stroke stratification scores in AF. We recruited consecutive patients (n=978) patients (49% male; median age 76) with permanent or paroxysmal AF on oral anticoagulants with acenocoumarol, from our out-patient anticoagulation clinic. After a median follow-up of 875 (IQR 706–1059) days, we recorded stroke/transient ischaemic attack (TIA), peripheral embolism, vascular events (acute coronary syndrome, acute heart failure and cardiac death) and all-cause mortality. During follow-up, 113 patients (4.82%/year) experienced an adverse cardiovascular event, of which 39 (1.66%/year) were strokes, 43 (1.83%/year) had an acute coronary syndrome and 32 (1.37%/year) had acute heart failure. Also, 102 patients (4.35%/year) died during the following up, 31 of them (1.32%/year) as a result of a thrombotic event. Based on c-statistics and the integrated discrimination improvement (IDI), CKD did not improve the prediction for stroke/systemic embolism, thrombotic events and all-cause mortality using the CHADS2 and CHA2DS2-VASc scores. In conclusion, evaluating renal function in AF patients is important as CKD would confer a poor overall prognosis in terms of thromboembolic events and all-cause mortality. Adding CKD to the CHADS2 and CHA2DS2-VASc stroke risk scores did not independently add predictive information.

Note: The review process for this manuscript was fully handled by Christian Weber, Editor in Chief.

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.

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.

New oral anticoagulants in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) develop bleeding and thrombotic tendencies, so the indication of anticoagulation at the onset of atrial fibrillation (AF) is complex. AF is the most common chronic cardiac arrhythmia, and thromboembolism and ischemic stroke in particular are major complications. In recent years, new oral anticoagulant drugs have been developed, and they have shown superiority over the classical AVK in preventing stroke, systemic embolism and bleeding risk, constituting an effective alternative to those resources.

ISPD Cardiovascular and Metabolic Guidelines in Adult Peritoneal Dialysis Patients Part II - Management of Various Cardiovascular Complications

Cardiovascular mortality has remained high in patients on peritoneal dialysis (PD) due to the high prevalence of various cardiovascular complications including coronary artery disease, left ventricular hypertrophy and dysfunction, heart failure, arrhythmia (especially atrial fibrillation), cerebrovascular disease, and peripheral arterial disease. In addition, nearly a quarter of PD patients develop sudden cardiac death as the terminal life event. Thus, it is essential to identify effective treatment that may lower cardiovascular mortality and improve survival of PD patients. The International Society for Peritoneal Dialysis (ISPD) commissioned a global workgroup in 2012 to formulate a series of recommendation statements regarding lifestyle modification, assessment and management of various cardiovascular risk factors, and management of the various cardiovascular complications to be published in 2 guideline documents. This publication forms the second part of the guideline documents and includes recommendation statements on the management of various cardiovascular complications in adult chronic PD patients. The documents are intended to serve as a global clinical practice guideline for clinicians who look after PD patients. We also define areas where evidence is clearly deficient and make suggestions for future research in each specific area.

Primary prevention of atrial fibrillation with beta-blockers in patients with end-stage renal disease undergoing dialysis

Current evidence suggests that beta-blocker lower the risk of development of atrial fibrillation (AF) and in-hospital stroke after cardiac surgery. This study was to assess whether beta-blockers could decrease incidence of new-onset AF in patients with end stage renal disease (ESRD). We identified patients from a nation-wide database called Registry for Catastrophic Illness, which encompassed almost 100% of the patients receiving dialysis therapy in Taiwan from 1995 to 2008. Propensity score matching and Cox’s proportional hazards regression model were used to estimate hazard ratios (HRs) for new-onset AF. Among 100066 patients, 41.7% received beta-blockers. After a median follow-up of 1500 days, the incidence of new-onset AF significantly decreased in patients treated with beta-blockers (HR = 0.483, 95% confidence interval = 0.437-0.534). The prevention of new-onset AF was significantly better in patients taking longer duration of beta-blockers therapy (P for time trend <0.001). The AF prevention effect remains robust in subgroup analyses. In conclusion, beta-blockers seem effective in the primary prevention of AF in ESRD patients. Hence, beta-blockers may be the target about upstream treatment of AF.

Clinical characteristics of hemodialysis patients with atrial fibrillation: The RAKUEN (Registry of atrial fibrillation in chronic kidney disease under hemodialysis from Niigata) study

BACKGROUND

Clinical characteristics, management, and outcomes in hemodialysis patients with atrial fibrillation (AF) remain unclear.

METHODS AND RESULTS

We studied 423 Japanese patients undergoing maintenance hemodialysis (age 65.2±12.4 years, male 70%, mean duration of hemodialysis 139±124 months). AF was present in 19% (n=82) and was independently related to increased age (odds ratio 1.070, 95% confidence interval 1.043-1.098), longer hemodialysis duration (odds ratio 1.006, 95% confidence interval 1.004-1.008), and congestive heart failure (odds ratio 2.749, 95% confidence interval 1.546-4.891). During observations lasting a mean of 36 months, the incidences of all-cause death, cardiovascular death, and major bleeding, in particular gastrointestinal bleeding, were significantly higher in the AF (n=82) than the non-AF (n=341) patients (p<0.001, p=0.004, p=0.002, p=0.027, respectively), but the incidence of ischemic stroke/systemic embolism was similar in the AF and non-AF patients. AF was independently associated with all-cause death (hazard ratio 1.728, 95% confidence interval 1.123-2.660) and major bleeding (hazard ratio 1.984, 95% confidence interval 1.010-3.896). Warfarin was prescribed in 33% of the AF patients, but the rates of all-cause death, ischemic stroke, and major bleeding during the study period were not significantly different between warfarin (n=27) and non-warfarin (n=55) groups.

CONCLUSIONS

In our hemodialysis patients, AF was a common comorbidity and was independently associated with all-cause death and major bleeding, but not with increased risk of ischemic stroke.

Atrial fibrillation and chronic kidney disease: focus on rivaroxaban

Renal insufficiency increases the risk of stroke and bleeding in atrial fibrillation patients. Although vitamin K antagonists reduce the risk of stroke in patients with moderate renal dysfunction, this observation is less clear in patients with renal impairment. Moreover, the risk of bleeding with vitamin K antagonists increases as renal function worsens. Maintaining international normalized ratio values within therapeutic targets is more difficult in patients with renal dysfunction, and those agents may cause warfarin-related nephropathy and vascular calcification. Rivaroxaban is the only nonvitamin K oral anticoagulant with a dose specifically tested in patients with moderate renal insufficiency. Rivaroxaban is effective for the prevention of stroke in atrial fibrillation patients with moderate renal dysfunction, with a lower risk of intracranial and fatal bleeding.

Understanding and Managing Atrial Fibrillation in Patients with Kidney Disease

Chronic kidney disease (CKD) is on the rise due to the increased rate of related comorbidities such as diabetes and hypertension. Patients with CKD are at higher risk of cardiovascular events and atrial fibrillation is more common in this patient population. It is estimated that the prevalence of chronic atrial fibrillation in patients with CKD is two to three times higher than general population. Furthermore, patients with CKD are less likely to stay in sinus rhythm. Atrial fibrillation presents a major burden in this population due to difficult treatment decisions in the setting of a lack of evidence from randomized clinical trials. Patients with CKD have higher risk of stroke with more than half having a CHADS2 score ≥ 2. Anticoagulation have been shown to significantly decrease embolic stroke risk, however bleeding complications such as hemorrhagic stroke is twofold higher with warfarin. Although newer novel anticoagulation drugs have shown promise with lower intracranial hemorrhage risk in comparison to warfarin, lack clinical trial data in CKD and the unavailability of an antidote remains an issue. In this review, we discuss the treatment options available including anticoagulation and the evidence behind them in patients with chronic kidney disease suffering from atrial fibrillation.

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.

The effects of a single dialysis session on atrial electromechanical conduction times and functions

BACKGROUND/AIMS

Abnormalities in atrial electromechanical delay (EMD) times and mechanical functions are considered as independent predictors of atrial fibrillation. However, to date, effects of a single hemodialysis (HD) session and acute volume-preload changes on atrial-EMD functions have not been investigated by Tissue Doppler Echocardiography (TDE). The aim of the present study was to evaluate atrial-EMD times and mechanical functions in HD patients.

METHODS

Thirty-five non-diabetic, normotensive HD patients and 35 healthy control subjects were enrolled in the study. Standard and TDE performed before mid-week dialysis session for hemodialysis group and on admission for control group.

RESULTS

Interatrial and left-right intraatrial-EMD intervals and left atrial mechanical volumes were significantly longer in hemodialysis group compared to controls (all p<0.01) and were reduced after HD session. Furthermore, removed ultrafiltration volume was associated with reduction in atrial-EMD intervals and functional volumes. LA-passive emptying volume, ultrafiltration volume, LV-E/E' ratio, and Vp were independent predictors of interatrial-EMD.

CONCLUSIONS

The present study confirms negative effects in HD patients of structural remodeling and reveals negative effects of electrical remodeling. Prolonged inter and intraatrial-EMD intervals should be the underlying pathophysiological factors of increased rate of atrial fibrillation in the HD population.

The association of ECG and echocardiographic abnormalities with sudden cardiac death in a dialysis patient cohort

BACKGROUND

Cardiovascular mortality is greater in dialysis patients than the general population. More specifically, sudden cardiac death (SCD) accounts for 26% of dialysis patient deaths. However, SCD risk assessment tools used in the general population are not adequate for dialysis patients indicating that the hierarchy of pathopysiological factors appears to be different. The aim of this study was to use simple bedside tests to determine parameters independently predictive of cardiovascular mortality and SCD in dialysis patients.

METHOD AND RESULTS

This was a sub-study of the Chronic Renal Insufficient Standards Implementations Study, a longitudinal cohort study of outcomes in CKD. ECG and echocardiographic abnormalities were assessed in a cross-section of prevalent dialysis patients. Patients were followed up until death or transplantation. Forward stepwise Cox regression then determined factors independently associated with all-cause, cardiovascular and SCD mortality. 323 patients were included (age 61.5 ± 14.6 years, 113 deaths, 66 cardiovascular deaths, 18 SCD). A number of factors were independently associated with all-cause mortality. These were age, time on dialysis, smoking, the difference between QRS and T-wave axes, resting heart rate, and pulmonary artery pressure (PAP) >35 mmHg. The only parameters predictive of SCD were elevated PAP (HR = 5.99, p = 0.05) and mitral regurgitation (HR = 6.71, p = 0.01).

CONCLUSION

That PAP is associated with SCD in dialysis patients demonstrates that the pathophysiological mechanism is likely to be different in these patients compared to the general population. Because of this, a population specific approach to risk stratification is advisable.

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.

Anticoagulation in Patients Aged ≥75 years with Atrial Fibrillation: Role of Novel Oral Anticoagulants

Atrial fibrillation (AF) is an important cause of preventable, disabling stroke and is increasingly prevalent with advancing age. As life expectancies increase around the world, AF-related stroke is a growing global public health concern. Most AF patients are elderly (≥75 years old) and increasing age is a consistent independent risk factor for AF-associated stroke. Warfarin anticoagulation is highly effective for stroke prevention in AF patients, but is underutilized especially in the elderly. Although elderly patients are at increased risk of hemorrhage with oral anticoagulants, the benefit for ischemic stroke reduction exceeds the risk of hemorrhage for most elderly patients. Consequently, age alone should not be considered a contraindication for anticoagulation. Novel oral anticoagulants such as dabigatran, rivaroxaban and apixaban are at least as effective as warfarin in preventing strokes in patients with AF. Relative to warfarin, these novel agents reduce the risk of intracranial hemorrhage, the most devastating complication of anticoagulation therapy in elderly AF patients. The novel oral anticoagulants are especially appealing for stroke prevention in elderly patients with AF.

The impact of haemodialysis on the outcomes of catheter ablation in patients with paroxysmal atrial fibrillation

AIMS

The outcomes of catheter ablation (CA) in patients with paroxysmal atrial fibrillation (PAF) who are undergoing haemodialysis (HD) have not been fully elucidated. This study aimed to determine the impact of HD on CA outcome in these patients.

METHODS AND RESULTS

We examined 1364 consecutive PAF patients (mean age, 61 ± 10 years) who underwent CA, including 32 (2.3%) patients undergoing HD. The patients undergoing HD had a significantly lower body mass index (P < 0.0001), higher CHADS2 score (P = 0.006), and higher prevalence of structural heart disease (P < 0.0001), hypertension (P = 0.002), and congestive heart failure (P = 0.02). Echocardiography indicated a larger left atrial diameter (P < 0.0001) and left ventricular diameter (P = 0.0002) in the HD patients. Haemodialysis was a significant predictor of AF recurrence (hazard ratio 2.56; 95% confidence interval 1.56-4.03; P = 0.0004) in the overall population. Sinus rhythm maintenance rates in the HD patients at 1, 3, and 5 years were 42.3, 37.6, and 19.7%, respectively, after the first procedure, and 64.7, 54.9, and 47.1%, respectively, after the final procedure (median, 2; range, 1-2 procedures); these rates were significantly lower than those in the non-HD patients (P < 0.0001). The 5-year survival rate was 78.1% in the HD patients.

CONCLUSION

Haemodialysis was significantly associated with AF recurrence after CA for PAF. However, an ∼50% success rate for sinus rhythm maintenance without antiarrhythmic drug therapy in HD patients suggested that CA could be an option for the treatment of AF.

Echocardiography to predict adverse cardiac and vascular events in patients with severe chronic kidney disease (stage 4): a prospective study

BACKGROUND

Cardiovascular disease is the primary cause of mortality and morbidity among patients with chronic kidney disease.

AIMS

To investigate whether echocardiography can predict the occurrence of major cardiovascular events in patients with severe chronic kidney disease.

PATIENTS

Patients with stable stage 4 chronic kidney disease (estimated glomerular filtration rate 15-29 mL/min/1.73 m(2)) and followed in the nephrology department were included. Clinical, biological, electrocardiographic and echocardiographic data were recorded. Endpoint was defined as fatal or non-fatal cardiovascular event (acute coronary syndrome, acute heart failure, stroke, sustained ventricular arrhythmias, arterial thrombotic events and death).

RESULTS

We included 71 patients (46 men); mean age 72±14 years. Mean glomerular filtration rate was 21.9±4.8 mL/min/1.73 m(2). Over a mean follow-up of 258±30 days, 18 (25%) patients reached endpoint (death in 7/18). Male sex, blood urea, atrial fibrillation, Sokolow index, left atrial size, pulmonary arterial pressure, indexed left ventricular mass and protodiastolic peak velocity of transmitral Doppler flow were significantly higher whereas left ventricular ejection fraction was significantly lower in these patients. By multivariable analysis, blood urea and left ventricular ejection fraction remained predictive of major cardiovascular event with odds ratios of 1.10 (95% confidence interval 1.02-1.18) and 0.93 (95% confidence interval 0.89-0.97), respectively. The negative predictive value was 95% when left ventricular ejection fraction was>50% with blood urea<15 mmol/L.

CONCLUSION

Patients with stage 4 chronic kidney disease are at high risk of major cardiovascular events and death. Echocardiographic evaluation is effective in identifying patients at highest risk of adverse cardiac events.

Renal impairment and ischemic stroke risk assessment in patients with atrial fibrillation: the Loire Valley Atrial Fibrillation Project

OBJECTIVES

This study sought to determine the risk of ischemic stroke (IS)/thromboembolism (TE) associated with renal impairment and its incremental predictive value over established risk stratification scores (congestive heart failure, hypertension, age ≥75 years, diabetes, previous stroke [CHADS2] and congestive heart failure, hypertension, age ≥75 years, diabetes, previous stroke, vascular disease, age 65 to 74 years, sex category (female) [CHA₂DS₂-VASc]) in patients with atrial fibrillation (AF).

BACKGROUND

Risk stratification schemes for prediction of IS/TE in patients with AF are validated but do not include renal impairment.

METHODS

Patients diagnosed with nonvalvular AF and available estimated glomerular filtration rate (eGFR) data in a 4-hospital institution between 2000 and 2010 were identified. The study population was stratified by renal impairment defined by serum creatinine level and by eGFR measured at time of diagnosis of AF. Independent risk factors of IS/TE (including renal impairment) were investigated in Cox regression models. The incremental predictive value of renal impairment over CHADS₂ and CHA₂DS₂-VASc were assessed with the c-statistic, net reclassification improvement, and integrated discrimination improvement. We focused on the 1-year outcomes in our analyses.

RESULTS

Of 8,962 eligible individuals, 5,912 (66%) had nonvalvular AF and available eGFR data. Renal impairment by both creatinine and eGFR definitions was associated with higher rates of IS/TE at 1 year, compared with normal renal function. After adjustment for CHADS₂ risk factors, renal impairment did not significantly increase the risk of IS/TE at 1 year (hazard ratio: 1.06; 95% confidence interval [CI]: 0.75 to 1.49 for renal impairment; and hazard ratio: 1.09; 95% CI: 0.84 to 1.41 for eGFR). When renal impairment was added to existing risk scoring systems for stroke/TE (CHADS₂ and CHA₂DS₂-VASc), it did not independently add to the predictive value of the scores, whether defined by serum creatinine level or eGFR. This was evident even when the analysis was confined to only those patients with at least 1 year of follow-up.

CONCLUSIONS

Renal impairment was not an independent predictor of IS/TE in patients with AF and did not significantly improve the predictive ability of the CHADS₂ or CHA₂DS₂-VASc scores.

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.

Chronic Kidney Disease and Atrial Fibrillation: A Contemporary Overview

Chronic kidney disease (CKD) is associated with substantial cardiovascular morbidity, including myocardial infarction, heart failure and stroke. Similar to CKD, atrial fibrillation (AF) is a prevalent arrhythmia that increases risk for both stroke and overall mortality. Recent studies demonstrate that both prevalence and incidence of AF is higher in patient with versus without renal impairment and risk for developing AF increases as renal function worsens. Potential mechanisms for the higher burden of AF in CKD patients include but are not limited to augmented sympathetic tone, activation of the renin-angiotensin-aldosterone system and myocardial remodeling. Similar to the general population, AF confers an increased risk for both stroke and overall mortality in the CKD population. The safety and efficacy of antithrombotic therapy across the spectrum of CKD remains unknown, however, as patients with advanced renal failure are frequently excluded from randomized trials. While treatment with vitamin K antagonists appears to reduce ischemic complications without significant bleeding harm in patients with mild to moderate CKD and AF, the risk benefit ratio of anticoagulation among thosewith advanced renal failure on dialysis requires further investigation. Prospective, randomized trials are war ranted to define the impact of antithrombotic therapy on reducing stroke risk in patients with both AF and CKD.