Monitoring of arrhythmia and sudden death in a hemodialysis population: The CRASH-ILR Study

Leadless pacemakers in patients with different stages of chronic kidney disease: real-world data from the updated i-LEAPER registry

BACKGROUND

Limited data are available on leadless pacemaker (LPM) outcomes according to different stages of chronic kidney disease (CKD).

OBJECTIVE

To investigate differences regarding safety and efficacy in LPMs patients stratified per different stages of renal function.

METHODS

Consecutive patients enrolled in the multicenter, international i-LEAPER registry were analyzed. Patients were divided into three groups according to CKD stage. The primary endpoint was the comparison of LPM-related major complication rate at implant and during follow-up. Differences in electrical performance were deemed secondary outcomes.

RESULTS

Among 1748 patients enrolled, 33% were CKD stage G3a/G3b and 9.4% were CKD stage G4/G5. CKD patients presented cardiovascular comorbidities more frequently. During a median follow-up of 39 [interquartile range (IQR) 18-59] months, major complications rate did not differ between groups (normal kidney function, NKF=1.8% vs CKD stage-G3a/G3b 2.9% vs CKD stage-G4/G5 2.4%, p=0.418). All-cause mortality resulted higher in CKD stage-G4/G5 when compared with NKF group (19.5% vs 9.8%, aHR:1.9, 95%CI 1.25-2.89, p=0.003). LPM electrical performance was comparable between groups, except for CKD patients who showed a slightly higher pacing threshold during the 1-month follow-up (NKF group 0.50 [IQR 0.35-0.70]V vs G3a/G3b group 0.56 [IQR 0.38-0.81]V vs G4/G5 group, 0.51 [0.38-0.84]V @0.24 msec, p<.001).

CONCLUSION

In a real-world setting, advanced CKD patients who underwent LPM implantation were underrepresented. Although all-cause mortality was higher in end-stage CKD, periprocedural complications and LPM performance were overall comparable between NKF and different stages of CKD, except for higher values of pacing threshold in CKD patients up to first-month follow-up.

New Insights on Cardiac Arrhythmias in Patients With Kidney Disease

The risk of arrhythmia and its management become increasingly complex as kidney disease progresses. This presents a multifaceted clinical challenge. Our discussion addresses these specific challenges relevant to patients as their kidney disease advances. We highlight numerous opportunities for enhancing the current standard of care within this realm. Additionally, this review delves into research concerning early detection, prevention, diagnosis, and treatment of various arrhythmias spanning the spectrum of kidney disease.

Arrhythmias and cardiac MRI associations in patients with established cardiac dystrophinopathy

AIMS

Some patients with cardiac dystrophinopathy die suddenly. Whether such deaths are preventable by specific antiarrhythmic management or simply indicate heart failure overwhelming medical therapies is uncertain. The aim of this prospective, cohort study was to describe the occurrence and nature of cardiac arrhythmias recorded during prolonged continuous ECG rhythm surveillance in patients with established cardiac dystrophinopathy and relate them to abnormalities on cardiac MRI.

METHODS AND RESULTS

A cohort of 10 patients (36.3 years; 3 female) with LVEF<40% due to Duchenne (3) or Becker muscular (4) dystrophy or Duchenne muscular dystrophy-gene carrying effects in females (3) were recruited, had cardiac MRI, ECG signal-averaging and ECG loop-recorder implants. All were on standard of care heart medications and none had prior history of arrhythmias.No deaths or brady arrhythmias occurred during median follow-up 30 months (range 13-35). Self-limiting episodes of asymptomatic tachyarrhythmia (range 1-29) were confirmed in 8 (80%) patients (ventricular only 2; ventricular and atrial 6). Higher ventricular arrhythmia burden correlated with extent of myocardial fibrosis (extracellular volume%, p=0.029; native T1, p=0.49; late gadolinium enhancement, p=0.49), but not with LVEF% (p=1.0) on MRI and atrial arrhythmias with left atrial dilatation. Features of VT episodes suggested various underlying arrhythmia mechanisms.

CONCLUSIONS

The overall prevalence of arrhythmias was low. Even in such a small sample size, higher arrhythmia counts occurred in those with larger scar burden and greater ventricular volume, suggesting key roles for myocardial stretch as well as disease progression in arrhythmogenesis. These features overlap with the stage of left ventricular dysfunction when heart failure also becomes overt. The findings of this pilot study should help inform the design of a definitive study of specific antiarrhythmic management in dystrophinopathy.

TRIAL REGISTRATION NUMBER

ISRCTN15622536.

Cardiac Device Therapy in Patients with Chronic Kidney Disease: An Update

Cardiovascular diseases (CVDs) and chronic kidney disease (CKD) are frequently interconnected and their association leads to an exponential increase in the risk of both fatal and non-fatal events. In addition, the burden of arrhythmias in CKD patients is increased. On the other hand, the presence of CKD is an important factor that influences the decision to pursue cardiac device therapy. Data on CKD patients with device therapy are scarce and mostly derives from observational studies and case reports. Cardiac resynchronization therapy (CRT) is associated with decreased mortality, reduced heart failure symptoms, and improved renal function in early stages of CKD. Implantable cardioverter defibrillators (ICDs) are associated with a significant reduction in the mortality of CKD patients only for the secondary prevention of sudden cardiac death. Cardiac resynchronization therapy with defibrillator (CRT-D) is preferred in patients who meet the established criteria. The need for cardiac pacing is increased three-fold in dialysis patients. CKD is an independent risk factor for infections associated with cardiac devices.

Effects of Spironolactone on Arrhythmias in Hemodialysis Patients: Secondary Results of the SPin-D Randomized Controlled Trial

Key Points

The effects of spironolactone on arrhythmia in patients receiving maintenance hemodialysis are unclear. In these post hoc analyses, spironolactone resulted in a higher frequency of bradycardia and conduction blocks, compared with placebo. Close monitoring may be warranted for patients on maintenance hemodialysis receiving MRAs, while definitive trial results are awaited.

Background

Patients receiving maintenance hemodialysis (HD) have a high incidence of cardiovascular events, including arrhythmia and sudden death. Spironolactone reduces the risk of cardiovascular events and sudden death in patients with heart failure, but the effects of spironolactone on arrhythmic events in patients treated with maintenance HD are unclear.

Methods

The Safety and Cardiovascular Efficacy of Spironolactone in Dialysis-Dependent ESRD (SPin-D) trial was a 36-week randomized, placebo-controlled, double-blind trial comparing three different doses of spironolactone with placebo in maintenance HD patients. We performed a post hoc analysis in a subset (n =57) who underwent extended electrocardiographic monitoring using a wearable device at baseline and follow-up. Generalized estimating equations models were fit to determine the associations of spironolactone (individual doses and combined) versus placebo on the incidence rate of predefined categories of arrhythmic events.

Results

The average age of participants was 55±12 years, 61% were male, and 77% were Black. The overall proportion of patients with at least one arrhythmia event was 43% (15/35) at baseline and 81% (43/53) at the end of follow-up. At the end of follow-up, the rate of bradycardic events or conduction blocks was higher in the combined spironolactone group, compared with placebo (82.4 versus 38.7 events/100 patient-days; P <0.001). Similar findings were noted in adjusted models, but did not meet statistical significance (adjusted rate ratio of 2.04; 95% confidence interval 0.83–5.05).

Conclusions

In a 36-week trial of patients receiving maintenance HD, a higher frequency of bradycardia and conduction blocks was observed among those treated with spironolactone treatment compared with placebo. Larger studies are required to investigate the longer-term effects of spironolactone on cardiac conduction in patients receiving HD.

Arrhythmia in chronic hemodialysis as a function of predialysis electrolytes and interdialytic interval

INTRODUCTION

People with end-stage renal disease on hemodialysis are at increased risk for death due to arrhythmia associated with the prolonged interdialytic interval that typically spans the weekend, with bradycardia being the arrhythmia most closely associated with sudden death. In this prospective observational study we assessed whether predialysis fluid and electrolytes values including hyperkalemia are risk factors for the arrhythmias associated with the prolonged interdialytic interval.

METHODS

Sixty patients on hemodialysis with a history of hyperkalemia underwent cardiac monitoring for 1 week. Arrhythmia frequency, average QTc interval, and average root mean square of successive differences (rMSSD) per 4-h period were reported. Predialysis electrolytes and electrocardiograms were collected prior to pre- and post-weekend dialysis sessions. Clinical variables were assessed for correlation with arrhythmias.

FINDINGS

Predialysis hyperkalemia occurred in 29 subjects and was more common at the post-weekend dialysis session. Bradycardia occurred in 11 subjects and increased before and during the post-weekend dialysis session, but was not correlated with any electrolyte or clinical parameter. Ventricular ectopy occurred in 50 subjects with diurnal variation unrelated to dialysis. Pre-dialysis prolonged QTc was common and not affected by interdialytic interval. Average QTc increased and rMSSD decreased during dialysis sessions and were not correlated with clinical parameters.

DISCUSSION

The results confirm that arrhythmias are prevalent in dialysis subjects with bradycardia particularly associated with the longer interdialytic interval; EKG markers of arrhythmia risk are increased during dialysis independent of interdialytic interval. Larger sample size and/or longer recording may be necessary to identify the clinical parameters responsible.

Association of Bradycardia and Asystole Episodes with Dialytic Parameters: An Analysis of the Monitoring in Dialysis (MiD) Study

Background

Bradycardia and asystole events are common among patients treated with maintenance hemodialysis. However, triggers of these events in patients on maintenance hemodialysis (HD), particularly during the long interdialytic period when these events cluster, are uncertain.

Methods

The Monitoring in Dialysis Study (MiD) enrolled 66 patients on maintenance HD who were implanted with loop recorders and followed for 6 months. We analyzed associations of predialysis laboratory values with clinically significant bradyarrhythmia or asystole (CSBA) during the 12 hours before an HD session. Associations with CSBA were analyzed with mixed-effect models. Adjusted negative binomial mixed-effect regression was used to estimate incidence rate ratios (IRR) for CSBA. We additionally evaluated associations of CSBA at any time during follow-up with time-averaged dialytic and laboratory parameters and associations of peridialytic parameters with occurrence of CSBA from the start of one HD session to the beginning of the next.

Results

There were 551 CSBA that occurred in the last 12 hours of the interdialytic interval preceding 100 HD sessions in 12% of patients and 1475 CSBA events in 23% of patients overall. We did not identify significant associations between dialytic parameters or serum electrolytes and CSBA in the last 12 hours of the interdialytic interval in adjusted analyses. Median time-averaged ultrafiltration rate was significantly higher in individuals without CSBA (9.8 versus 8, P=0.04). Use of dialysate sodium concentrations ≤135 (versus 140) mEq/L was associated with a reduced risk of CSBA from the start of one session to the beginning of next.

Conclusions

Although a few factors had modest associations with CSBA in some analyses, we did not identify any robust associations of modifiable parameters with CSBA in the MiD Study. Further investigation is needed to understand the high rates of arrhythmia in the hemodialysis population.

Arrhythmia prevalence and sudden death risk in adults with the m.3243A>G mitochondrial disorder

AIMS

To define the prevalence of non-sustained tachyarrhythmias and bradyarrhythmias in patients with the m.3243A>G mitochondrial genotype and a previously defined, profile, associated with 'high sudden-death risk'.

METHODS AND RESULTS

Patients at high risk of sudden death because of combinations of ventricular hypertrophy, mitochondrial encephalopathy, lactic acidosis and stroke-like episodes family phenotype, epilepsy or high mutation load, due to the m.3243A>G mutation, were identified from a mitochondrial cohort of 209 patients. All recruited had serial ECG and echo assessments previously according to schedule, had an ECG-loop recorder implanted and were followed for as long as the device allowed. Devices were programmed to detect non-sustained brady- or tachy-arrhythmias. This provided comprehensive rhythm surveillance and automatic downloads of all detections to a monitoring station for cardiology interpretation. Those with sinus tachycardia were treated with beta-blockers and those with ventricular hypertrophy received a beta-blocker and ACE-inhibitor combination.Nine consecutive patients, approached (37.2±3.9 years, seven males) and consented, were recruited. None died and no arrhythmias longer than 30s duration occurred during 3-year follow-up. Three patients reported palpitations but ECGs correlated with sinus rhythm. One manifest physiological, sinus pauses >3.5 s during sleep and another had one asymptomatic episode of non-sustained ventricular tachycardia.

CONCLUSIONS

Despite 'high-risk' features for sudden death, those studied had negligible prevalence of arrhythmias over prolonged follow-up. By implication, the myocardium in this genotype is not primarily arrhythmogenic. Arrhythmias may not explain sudden death in patients without Wolff-Parkinson-White or abnormal atrioventricular conduction or, it must require a confluence of other, dynamic, proarrhythmic factors to trigger them.

Prognostic Effect of Underlying Chronic Kidney Disease and Renal Replacement Therapy on the Outcome of Patients after Out-of-Hospital Cardiac Arrest: A Nationwide Observational Study

Background and Objectives: This study assessed the prognostic value of underlying chronic kidney disease (CKD) and renal replacement therapy (RRT) on the clinical outcomes from out-of-hospital cardiac arrest (OHCA). Materials and Methods: This retrospective study was conducted utilizing the population-based OHCA data of South Korea between 2008 and 2018. Adult (>18 years) OHCA patients with a medical cause of cardiac arrest were included and classified into three categories based on the underlying CKD and RRT: (1) non-CKD group; (2) CKD without RRT group; and (3) CKD with RRT group. A total of 13,682 eligible patients were included (non-CKD, 9863; CKD without RRT, 1778; CKD with RRT, 2041). From the three comparison subgroups, data with propensity score matching were extracted. The influence of CKD and RRT on patient outcomes was assessed using propensity score matching and multivariate logistic regression analyses. The primary outcome was survival at hospital discharge and the secondary outcome was a good neurological outcome at hospital discharge. Results: The two CKD groups (CKD without RRT and CKD with RRT) showed no significant difference in survival at hospital discharge compared with the non-CKD group (CKD without RRT vs. non-CKD, p > 0.05; CKD with RRT vs. non-CKD, p > 0.05). The non-CKD group had a higher chance of having good neurological outcomes than the CKD groups (non-CKD vs. CKD without RRT, p < 0.05; non-CKD vs. CKD with RRT, p < 0.05) whereas there was no significant difference between the two CKD groups (CKD without RRT vs. CKD with RRT, p > 0.05). Conclusions: Compared with patients without CKD, the underlying cause of CKD—regardless of RRT—may be linked to poor neurological outcomes. Underlying CKD and RRT had no effect on the survival at hospital discharge.

A Comparison of Hemodialysis and Peritoneal Dialysis in Patients with Cardiovascular Disease

The high prevalence of cardiovascular disease is caused by the traditional cardiovascular risk factors common among end-stage renal disease patients, and nontraditional risk factors attributed to underlying kidney disease, including chronic inflammation, anemia, bone mineral disease, and the dialysis procedure itself. Individualization of the treatment of cardiovascular disease in end-stage renal disease that could impact the underlying mechanisms of the cardiovascular diseases is important to improve outcomes. This article reviews and compares hemodialysis and peritoneal dialysis in association with different cardiovascular diseases affecting dialysis patients, including hypertension, coronary artery disease, myocardial stunning, cardiac arrhythmias, heart failure, and the cardiorenal syndrome.

Patients' and family members' perspectives on arrhythmias and sudden death in dialysis: the HeartLink focus groups pilot study

BACKGROUND

Patients receiving dialysis face a high risk of cardiovascular disease, arrhythmia and sudden cardiac death. Few patients, however, are aware of this risk. Implantable cardiac monitors are currently available for clinical use and can continuously monitor cardiac rhythms without the need for transvenous leads. Our goal was to gauge patients' and family members' perceptions of these risks and to identify their concerns about cardiac monitors.

METHODS

Two 90-minute focus groups were conducted: one with patients receiving in-center hemodialysis and one with their family members. Trained moderators assessed: (1) knowledge of cardiovascular disease; (2) cardiovascular disease risk in dialysis; (3) risk of death due to cardiovascular disease; (4) best ways to convey this risk to patients/families; and (5) concerns about cardiac monitors. The sessions were audiotaped, transcribed, and independently analyzed by two reviewers to identify core themes. Emblematic quotations were chosen to illustrate the final themes.

RESULTS

Nine adult patients and three family members participated. Patients felt education was inadequate and had little knowledge of arrhythmias. Patients'/families' concerns regarding cardiac monitors were related to adverse effects, the notification process, and cosmetic effects. Patients/families felt that nephrologists, not dialysis staff, would be the best source for education.

CONCLUSIONS

The preliminary data from this small study population suggest that patients/families are not well aware of the high risk of arrhythmia and sudden cardiac death in dialysis. Further investigation is required to gauge this awareness among patients/families and to assess their impressions of implantable cardiac monitors for arrhythmia detection and management.

Asystole episodes and bradycardia in patients with end-stage renal disease

BACKGROUND

Knowledge of arrhythmias in patients with end-stage renal disease (ESRD) is mainly based on ambulatory electrocardiography (ECG) studies and observations during haemodialysis. We used insertable cardiac monitors to define the prevalence of arrhythmias, focusing on bradyarrhythmias, in ESRD patients treated with several dialysis modes including home therapies. Moreover, we assessed whether these arrhythmias were detected in baseline or ambulatory ECG recordings.

METHODS

Seventy-one patients with a subcutaneously insertable cardiac monitor were followed for up to three years. Asystole (≥4.0 secs) and bradycardia (heart rate <30 bpm for ≥4 beats) episodes, ventricular tachyarrhythmias and atrial fibrillation were collected and verified visually. A baseline ECG and a 24-48-hour ambulatory ECG were recorded at recruitment and once a year thereafter.

RESULTS

At recruitment, forty-four patients were treated in in-center haemodialysis, 12 in home haemodialysis and 15 in peritoneal dialysis. During a median follow-up of 34.4 months, 18 (25.4%) patients had either an asystolic or a bradycardic episode. The median length of each patient's longest asystole was 6.6 seconds and that of a bradycardia 13.5 seconds. Ventricular tachyarrhythmias were detected in 16 (23%) patients, and atrial fibrillation in 34 (51%) patients. In-center haemodialysis and type II diabetes were significantly more frequent among those with bradyarrhythmias whereas no bradyarrhythmias were found in home haemodialysis. No bradyarrhythmias were evident in baseline or ambulatory ECG recordings.

CONCLUSIONS

Remarkably many patients with ESRD had bradycardia or asystolic episodes, but these arrhythmias were not detected by baseline or ambulatory ECG.

Out-of-hospital cardiac arrest in dialysis patients

Purpose

The aim of the study was to assess whether a history of dialysis is related to cardiopulmonary resuscitation (CPR) attempts and survival to hospital admission in patients with out-of-hospital cardiac arrest (OHCA).

Methods

The databases of the POL-OHCA registry and of emergency medical calls in the Command Support System of the State of Emergency Medicine (CSS) were searched to identify patients with OHCA and a history of dialysis. A total of 264 dialysis patient with OHCA were found: 126 were dead on arrival of emergency medical services (EMS), and 138 had OHCA with CPR attempts. Data from the POL-OHCA registry for patients with CPR attempts, including age, sex, place of residence, first recorded rhythm, defibrillation during CPR, and priority dispatch codes, were collected and compared between patients with and without dialysis.

Results

CPR attempts by EMS were undertaken in 138 dialyzed patients (52.3%). The analysis of POL-OHCA data revealed no differences in age, sex, place of residence, first recorded rhythm, and priority dispatch codes between patients with and without dialysis. Defibrillation was less frequent in dialysis patients (P = 0.04). A stepwise logistic regression analysis revealed no association between survival to hospital admission and a history of hemodialysis (odds ratio = 1.12; 95% CI 0.74–1.70, P = 0.60).

Conclusions

A history of dialysis in patients with OHCA does not affect the rate of CPR attempts by EMS or a short-term outcome in comparison with patients without dialysis. Defibrillation during CPR is less common in patients on dialysis than in those without.

A Systematic Review of the Incidence of Arrhythmias in Hemodialysis Patients Undergoing Long-Term Monitoring With Implantable Loop Recorders

Introduction

Establishing the frequency and nature of arrhythmias in hemodialysis (HD) is an important step in improving outcomes of these patients. We undertook this systematic review and meta-analysis to characterize arrhythmia frequency in maintenance HD patients.

Methods

We identified studies on arrhythmias in adult patients on maintenance HD detected via implantable loop recorders (ILRs). Studies included were in English and reported ILR-detected arrhythmia incidence in HD patients. Data were extracted by one author using electronic spreadsheets and verified by a second author. Random effects models were used for pooled inferences. The I² statistic was used to quantify heterogeneity.

Results

Five studies qualified for inclusion (317 patients). The overall estimates for the annualized rate of death and sudden cardiac death (SCD) was 0.14 (95% confidence interval [CI]: 0.11–0.18) and 0.06 (95% CI: 0.03–0.10), respectively. Across all 5 studies, the combined annualized rate of patients experiencing at least 1 bradycardia/asystole event was 0.19 (95% CI: 0.11–0.33) but heterogeneity was high (I² = 79.8%). The average annualized rate of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) episodes (0.02, 95% CI: 0.01–0.05) was significantly lower (P < 0.001) than the rate of bradycardia/asystole reported in the same patients. Incidence of atrial fibrillation (AF) varied significantly across the studies (from 0.07 to 0.83 patients per year) reflecting variable definitions (new-onset vs. total number of episodes).

Conclusion

The incidence of arrhythmias among chronic HD patients is high, with bradycardia/asystole occurring more frequently than ventricular arrhythmias. Additional studies to refine estimates particularly of AF are needed.

Chronic kidney disease and undiagnosed atrial fibrillation in individuals with diabetes

Background

Diabetes is an independent risk factor for atrial fibrillation (AF), which is associated with increases in mortality and morbidity, as well as a diminished quality of life. Renal involvement in diabetes is common, and since chronic kidney disease (CKD) shares several of the same putative mechanisms as AF, it may contribute to its increased risk in individuals with diabetes. The objective of this study is to identify the relationship between CKD and the rates of newly-diagnosed AF in individuals with diabetes taking part in a screening program using a self-applied wearable electrocardiogram (ECG) patch.

Materials and methods

The study included 608 individuals with a diagnosis of diabetes among 1738 total actively monitored participants in the prospective mHealth Screening to Prevent Strokes (mSToPS) trial. Participants, without a prior diagnosis of AF, wore an ECG patch for 2 weeks, twice, over a 4-months period and followed clinically through claims data for 1 year. Definitions of CKD included ICD-9 or ICD-10 chronic renal failure diagnostic codes, and the Health Profile Database algorithm. Individuals requiring dialysis were excluded from trial enrollment.

Results

Ninety-six (15.8%) of study participants with diabetes also had a diagnosis of CKD. Over 12 months of follow-up, 19 new cases of AF were detected among the 608 participants. AF was newly diagnosed in 7.3% of participants with CKD and 2.3% in those without (P < 0.05) over 12 months of follow-up. In a univariate Cox proportional hazard regression analysis, the risk of incident AF was 3 times higher in individuals with CKD relative to those without CKD: hazard ratios (HR) 3.106 (95% CI 1.2–7.9). After adjusting for the effect of age, sex, and hypertension, the risk of incident AF was still significantly higher in those with CKD: HR 2.886 (95% CI 1.1–7.5).

Conclusion

Among individuals with diabetes, CKD significantly increases the risk of incident AF. Identification of AF prior to clinical symptoms through active ECG screening could help to improve the clinical outcomes in individuals with CKD and diabetes.

Temporal changes in dialysate [Na+] prescription from 1996 to 2018 and their clinical significance as judged from a meta-regression of clinical trials

Over the last two decades, the clinical care of dialysis patients has refocused sharply on fluid volume control. Dialysate [Na⁺] is a key, albeit under-investigated, clinical tool for manipulation of fluid volume on dialysis. In the article, we firstly use data from the Dialysis Outcomes and Practice Patterns Study to document the global decrease in dialysate [Na⁺] that has occurred from 1996 to 2018, and demonstrate the virtual disappearance of [Na⁺] profiling from routine dialysis practice over the same period. Second, we used data from previously synthesized randomized clinical trial evidence combined with that of a more recently published trail to assess the clinical significance of these changes, estimating the effects of different levels of low dialysate [Na⁺] on key clinical outcomes. Our analyses suggest that current levels of dialysate [Na⁺] in some health jurisdictions are possibly causing harm to many patients, especially given that real world populations are significantly less robust and more vulnerable than clinical trial ones. To quote a recent editorial, "more evidence needed before lower dialysate sodium concentrations can be recommended." That evidence is coming, and no further changes should be made to default customary practice until it is available.

The risk factors associated with treatment-related mortality in 16,073 kidney transplantation-A nationwide cohort study

Mortality at an early stage after kidney transplantation is a catastrophic event. Treatment-related mortality (TRM) within 1 or 3 months after kidney transplantation has been seldom reported. We designed a retrospective observational cohort study using a national population-based database, which included information about all kidney recipients between 2003 and 2016. A total of 16,073 patients who underwent kidney transplantation were included. The mortality rates 1 month (early TRM) and 3 months (TRM) after transplantation were 0.5% (n = 74) and 1.0% (n = 160), respectively. Based on a multivariate analysis, older age (hazard ratio [HR] = 1.06; P < 0.001), coronary artery disease (HR = 3.02; P = 0.002), and hemodialysis compared with pre-emptive kidney transplantation (HR = 2.53; P = 0.046) were the risk factors for early TRM. Older age (HR = 1.07; P < 0.001), coronary artery disease (HR = 2.88; P < 0.001), and hemodialysis (HR = 2.35; P = 0.004) were the common independent risk factors for TRM. In contrast, cardiac arrhythmia (HR = 1.98; P = 0.027) was associated only with early TRM, and fungal infection (HR = 2.61; P < 0.001), and epoch of transplantation (HR = 0.34; P < 0.001) were the factors associated with only TRM. The identified risk factors should be considered in patient counselling, selection, and management to prevent TRM.

Intradialytic Hypotension and Cardiac Arrhythmias in Patients Undergoing Maintenance Hemodialysis: Results from the Monitoring in Dialysis Study

BACKGROUND AND OBJECTIVES

Patients receiving maintenance hemodialysis (HD) have a high incidence of cardiac events, including arrhythmia and sudden death. Intradialytic hypotension (IDH) is a common complication of HD and is associated with development of reduced myocardial perfusion, a potential risk factor for arrhythmia.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We analyzed data from the Monitoring in Dialysis study, which used implantable loop recorders to detect and continuously monitor electrocardiographic data from patients on maintenance HD (n=66 from the United States and India) over a 6-month period (n=4720 sessions). Negative binomial mixed effects regression was used to test the association of IDH₂₀ (decline in systolic BP >20 mm Hg from predialysis systolic BP) and IDH_0-20 (decline in systolic BP 0-20 mm Hg from predialysis systolic BP) with clinically significant arrhythmia (bradycardia≤40 bpm for ≥6 seconds, asystole≥3 seconds, ventricular tachycardia ≥130 bpm for ≥30 seconds, or patient-marked events) during HD.

RESULTS

The median age of participants was 58 (25th-75th percentile, 49-66) years; 70% were male; and 65% were from the United States. IDH occurred in 2251 (48%) of the 4720 HD sessions analyzed, whereas IDH_0-20 occurred during 1773 sessions (38%). The number of sessions complicated by least one intradialytic clinically significant arrhythmia was 27 (1.2%) where IDH₂₀ occurred and 15 (0.8%) where IDH_0-20 occurred. Participants who experienced IDH₂₀ (versus not) had a nine-fold greater rate of developing an intradialytic clinically significant arrhythmia (incidence rate ratio, 9.4; 95% confidence interval, 3.0 to 29.4), whereas IDH_0-20 was associated with a seven-fold higher rate (incidence rate ratio, 7.2; 95% confidence interval, 2.1 to 25.4).

CONCLUSIONS

IDH is common in patients on maintenance HD and is associated with a greater risk of developing intradialytic clinically significant arrhythmia.

Effect of Low-Sodium versus Conventional Sodium Dialysate on Left Ventricular Mass in Home and Self-Care Satellite Facility Hemodialysis Patients: A Randomized Clinical Trial

BACKGROUND

Fluid overload in patients undergoing hemodialysis contributes to cardiovascular morbidity and mortality. There is a global trend to lower dialysate sodium with the goal of reducing fluid overload.

METHODS

To investigate whether lower dialysate sodium during hemodialysis reduces left ventricular mass, we conducted a randomized trial in which patients received either low-sodium dialysate (135 mM) or conventional dialysate (140 mM) for 12 months. We included participants who were aged >18 years old, had a predialysis serum sodium ≥135 mM, and were receiving hemodialysis at home or a self-care satellite facility. Exclusion criteria included hemodialysis frequency >3.5 times per week and use of sodium profiling or hemodiafiltration. The main outcome was left ventricular mass index by cardiac magnetic resonance imaging.

RESULTS

The 99 participants had a median age of 51 years old; 67 were men, 31 had diabetes mellitus, and 59 had left ventricular hypertrophy. Over 12 months of follow-up, relative to control, a dialysate sodium concentration of 135 mmol/L did not change the left ventricular mass index, despite significant reductions at 6 and 12 months in interdialytic weight gain, in extracellular fluid volume, and in plasma B-type natriuretic peptide concentration (ratio of intervention to control). The intervention increased intradialytic hypotension (odds ratio [OR], 7.5; 95% confidence interval [95% CI], 1.1 to 49.8 at 6 months and OR, 3.6; 95% CI, 0.5 to 28.8 at 12 months). Five participants in the intervention arm could not complete the trial because of hypotension. We found no effect on health-related quality of life measures, perceived thirst or xerostomia, or dietary sodium intake.

CONCLUSIONS

Dialysate sodium of 135 mmol/L did not reduce left ventricular mass relative to control, despite improving fluid status.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

The Australian New Zealand Clinical Trials Registry, ACTRN12611000975998.

In-Hospital Cardiac Arrest Resuscitation Practices and Outcomes in Maintenance Dialysis Patients

BACKGROUND AND OBJECTIVES

Patients on maintenance dialysis with in-hospital cardiac arrest have been reported to have worse outcomes relative to those not on dialysis; however, it is unknown if poor outcomes are related to the quality of resuscitation. Using the Get With The Guidelines-Resuscitation (GWTG-R) registry, we examined processes of care and outcomes of in-hospital cardiac arrest for patients on maintenance dialysis compared with nondialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used GWTG-R data linked to Centers for Medicare and Medicaid data to identify patients with ESKD receiving maintenance dialysis from 2000 to 2012. We then case-matched adult patients on maintenance dialysis to nondialysis patients in a 1:3 ratio on the basis of age, sex, race, hospital, and year of arrest. Logistic regression models with generalized estimating equations were used to assess the association of in-hospital cardiac arrest and outcomes by dialysis status.

RESULTS

After matching, there were a total of 31,144 GWTG-R patients from 372 sites, of which 8498 (27%) were on maintenance dialysis. Patients on maintenance dialysis were less likely to have a shockable initial rhythm (20% versus 21%) and less likely to be within the intensive care unit at the time of arrest (46% versus 47%) compared with nondialysis patients; they also had lower composite scores for resuscitation quality (89% versus 90%) and were less likely to have defibrillation within 2 minutes (54% versus 58%). After adjustment, patients on maintenance dialysis had similar adjusted odds of survival to discharge (odds ratio [OR], 1.05; 95% confidence interval [95% CI], 0.97 to 1.13), better acute survival (OR, 1.33; 95% CI, 1.26 to 1.40), and were more likely to have favorable neurologic status (OR, 1.12; 95% CI, 1.04 to 1.22) compared with nondialysis patients.

CONCLUSIONS

Although there appears to be opportunities to improve the quality of in-hospital cardiac arrest care for among those on maintenance dialysis, survival to discharge was similar for these patients compared with nondialysis patients.

The prevalence of fragmented QRS and its relationship with left ventricular systolic function in chronic kidney disease

Objective

To investigate the prevalence of fragmented QRS (fQRS) on electrocardiograms (ECG) in patients with different stages of chronic kidney disease (CKD) and to examine the association between fQRS and left ventricular systolic function.

Methods

This retrospective study analysed clinical and laboratory data from consecutive patients with CKD. The relationship between fQRS and left ventricular systolic function was evaluated using univariate and multivariate logistic regression analyses.

Results

A total of 310 patients (186 males; mean ± SD age, 52.24 ± 15.72 years) with CKD participated in this study. The prevalence of fQRS was 30.32% (94 of 310 patients). The prevalence of fQRS was more common in the inferior leads (53.19%; 50 of 94) compared with the anterior leads (21.28%; 20 of 94) and the lateral leads (25.53%; 24 of 94). Multivariate logistic regression analysis showed that left ventricular ejection fraction (odds ratio [OR] 1.356; 95% confidence interval [CI] 1.022, 2.036) and coronary artery disease (OR 2.355; 95% CI 1.056, 5.251) were independent risk factors of fQRS in patients with CKD.

Conclusion

The fQRS was prevalent in patients with CKD regardless of the CKD stage.

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.

Sudden Cardiac Death in End-Stage Renal Disease

The challenge presented by sudden cardiac death in dialysis patients is to better define risk factors and delineate multiple etiologies. Only then can therapy be tailored to the highest risk patients and the incidence of sudden cardiac death be reduced. This article details the many possible etiologies and presents a brief overview of more recent research that may in the future prove of great benefit in improving the mortality of our patients with end-stage renal disease.

Advanced Cardiac Signal Recording

Implantable loop recorders allow prolonged and continuous single-lead electrocardiogram recording, with the pivotal addition of remote monitoring. They have significantly shortened time to electrocardiographic diagnosis and appropriate therapy of many bradyarrhythmias/tachyarrhythmias and proved helpful in arrhythmia burden definition, offering invaluable information in the diagnostic workup for syncope and atrial fibrillation. Advanced cardiac signal recording is also possible by transesophageal catheters. They have been used to orient diagnosis during wide and narrow QRS complex tachycardias and also to perform minimally invasive pacing. Intracardiac electrophysiologic study remains, however, essential for diagnosis of several arrhythmias in the perspective of curative catheter ablation.

Rates of Cardiac Rhythm Abnormalities in Patients with CKD and Diabetes

BACKGROUND AND OBJECTIVES

Cardiac arrhythmias increase mortality and morbidity in CKD. We evaluated the rates of subclinical arrhythmias in a population with type 2 diabetes and patients with moderate to severe CKD who were not on dialysis.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

This is a prospective observational study, using continuous ambulatory cardiac monitors to determine the rate of atrial and ventricular arrhythmias, as well as conduction abnormalities in this group.

RESULTS

A total of 38 patients (34% women), with mean eGFR of 38±13 ml/min per 1.73 m², underwent ambulatory cardiac monitoring for 11.2±3.9 days. The overall mean rate of any cardiac arrhythmia was 88.8 (95% confidence interval [95% CI], 27.1 to 184.6) episodes per person-year (PY). A history of cardiovascular disease was associated with a higher rate of detected arrhythmia (rate ratio, 5.87; 95% CI, 1.37 to 25.21; P<0.001). The most common arrhythmia was atrial fibrillation, which was observed in two participants with known atrial fibrillation and was a new diagnosis in four patients (11%), none of whom experienced symptoms. Overall, atrial fibrillation episodes occurred at a rate of 37.6 (95% CI, 2.4 to 112.3) per PY. Conduction abnormalities were found in eight patients (21%), a rate of 26.5 (95% CI, 4.2 to 65.5) per PY. Rates of ventricular arrhythmias were low (14.5 per PY; 95% CI, 4.3 to 32.0) and driven by premature ventricular contractions.

CONCLUSIONS

Cardiac rhythm abnormalities are common in patients with diabetes with moderate to severe CKD not requiring dialysis. Rates of atrial fibrillation are high and episodes are asymptomatic. Future studies are needed to determine the role of screening and upstream therapy of cardiac arrhythmias in this group.

Outcomes for Hemodialysis Patients Given Cardiopulmonary Resuscitation for Cardiac Arrest at Outpatient Dialysis Clinics

BACKGROUND

Out-of-hospital cardiac arrest, the leading cause of death among patients on hemodialysis, occurs frequently within outpatient dialysis centers. Practice guidelines recommend resuscitation training for all dialysis clinic staff and on-site defibrillator availability, but the extent of staff involvement in cardiopulmonary resuscitation (CPR) efforts and its association with outcomes is unknown.

METHODS

We used data from the Cardiac Arrest Registry to Enhance Survival and the Centers for Medicare & Medicaid Services dialysis facility database to identify patients who had cardiac arrest within outpatient dialysis clinics between 2010 and 2016 in the southeastern United States. We compared outcomes of patients who received dialysis staff-initiated CPR with those who did not until the arrival of emergency medical services (EMS).

RESULTS

Among 398 OHCA events in dialysis clinics, 66% of all patients presented with a nonshockable initial rhythm. Dialysis staff initiated CPR in 81.4% of events and applied defibrillators before EMS arrival in 52.3%. Staff were more likely to initiate CPR among men and witness cardiac arrests, and were more likely to provide CPR within larger dialysis clinics. Staff-initiated CPR was associated with a three-fold increase in the odds of hospital discharge and favorable neurologic status on discharge. There was no overall association between staff-initiated defibrillator use and outcomes, but there was a nonsignificant trend toward improved survival to hospital discharge in the subgroup with shockable initial cardiac arrest rhythms.

CONCLUSIONS

Dialysis staff-initiated CPR was associated with a large increase in survival but was only performed in 81% of cardiac arrest events. Further investigations should focus on understanding the potential facilitators and barriers to CPR in the dialysis setting.

Sudden Cardiac Death in Dialysis: Arrhythmic Mechanisms and the Value of Non-invasive Electrophysiology

Sudden Cardiac Death (SCD) is the leading cause of cardiovascular death in dialysis patients. This review discusses potential underlying arrhythmic mechanisms of SCD in the dialysis population. It examines recent evidence from studies using implantable loop recorders and from electrophysiological studies in experimental animal models of chronic kidney disease. The review summarizes advances in the field of non-invasive electrophysiology for risk prediction in dialysis patients focusing on the predictive value of the QRS-T angle and of the assessments of autonomic imbalance by means of heart rate variability analysis. Future research directions in non-invasive electrophysiology are identified to advance the understanding of the arrhythmic mechanisms. A suggestion is made of incorporation of non-invasive electrophysiology procedures into clinical practice. Key Concepts: - Large prospective studies in dialysis patients with continuous ECG monitoring are required to clarify the underlying arrhythmic mechanisms of SCD in dialysis patients. - Obstructive sleep apnoea may be associated with brady-arrhythmias in dialysis patients. Studies are needed to elucidate the burden and impact of sleeping disorders on arrhythmic complications in dialysis patients. - The QRS-T angle has the potential to be used as a descriptor of uremic cardiomyopathy. - The QRS-T angle can be calculated from routine collected surface ECGs. Multicenter collaboration is required to establish best methodological approach and normal values. - Heart Rate Variability provides indirect assessment of cardiac modulation that may be relevant for cardiac risk prediction in dialysis patients. Short-term recordings with autonomic provocations are likely to overcome the limitations of out of hospital 24-h recordings and should be prospectively assessed.

Arrhythmia in hemodialysis patients and its relation to sudden death

Sudden death in patients on hemodialysis is believed to be due to arrhythmia, but the evidence for this is surprisingly limited. Five studies involving implantable loop recorders in patients on hemodialysis have now been published, and 4 have shown that bradyarrhythmia rather than tachyarrhythmia are the pre-eminent arrhythmic associations of fatal events. The Monitoring in Dialysis study, reported in this issue, sheds new light on the relationships of arrhythmia to the conventional 3-session weekly hemodialysis cycle.

Cardiac implantable electronic device and vascular access: Strategies to overcome problems

For arrhythmia treatment or sudden cardiac death prevention in hemodialysis patients, there is a frequent need for placement of a cardiac implantable electronic device (pacemaker, implantable cardioverter defibrillator, or cardiac resynchronization device). Leads from a cardiac implantable electronic device can cause central vein stenosis and carry the risk of tricuspid regurgitation or contribute to infective endocarditis. In patients with end-stage kidney disease requiring vascular access and cardiac implantable electronic device, the best strategy is to create an arteriovenous fistula on the contralateral upper limb for a cardiac implantable electronic device and avoidance of central vein catheter. Fortunately, cardiac electrotherapy is moving toward miniaturization and less transvenous wires. Whenever feasible, one should avoid transvenous leads and choose alternative options such as subcutaneous implantable cardioverter defibrillator, epicardial leads, and leadless pacemaker. Based on recent reports on the leadless pacemaker/implantable cardioverter defibrillator effectiveness, in patients with rapid progression of chronic kidney disease (high risk of renal failure) or glomerular filtration rate <20 mL/min/1.73 m², this option should be considered by the implanting cardiologist for future access protection.