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.

Arrhythmia and Time of Day in Maintenance Hemodialysis: Secondary Analysis of the Monitoring in Dialysis Study.

Rationale & Objective: The incidence of arrhythmia varies by time of day. How this affects individuals on maintenance dialysis is uncertain. Our objective was to quantify the relationship of arrhythmia with the time of day and timing of dialysis. Study Design: Secondary analysis of the Monitoring in Dialysis study, a multicenter prospective cohort study. Settings & Participants: Loop recorders were implanted for continuous cardiac monitoring in 66 participants on maintenance dialysis with a follow up of 6 months. Exposure: Time of day based on 6-hour intervals. Outcomes: Event rates of clinically significant arrhythmia. Analytical Approach: Negative binomial mixed effects regression models for repeated measures were used to evaluate data from the Monitoring in Dialysis study for differences in diurnal patterns of clinically significant arrhythmia among those with end-stage kidney disease with heart failure and end-stage kidney disease alone. We additionally analyzed rates according to presence of heart failure, time of dialysis shift, and dialysis versus nondialysis day. Results: Rates of clinically significant arrhythmia peaked between 12:00 AM and 5:59 AM and were more than 1.5-fold as frequent during this interval than the rest of the day. In contrast, variations in atrial fibrillation peaked between 6:00 AM and 11:59 AM, but variations across the day were qualitatively small. Clinically significant arrhythmia occurred at numerically higher rate in individuals with end-stage kidney disease and heart failure (5.9 events/mo; 95% CI, 1.3-26.8) than those without heart failure (4.0 events/mo; 95% CI, 0.9-17.9). Although differences in overall rate were not significant, their periodicity was significantly different (P < 0.001), with a peak between 12:00 AM and 6:00 AM with kidney failure alone and between 6:00 AM and 11:59 AM in those with heart failure. Although the overall clinically significant arrhythmia rate was similar in morning compared with evening dialysis shifts (P = 0.43), their periodicity differed with a peak between 12:00 AM and 5:59 AM in those with AM dialysis and a later peak between 6:00 AM and 11:59 AM in those with PM shifts. Limitations: Post hoc analysis, unable to account for unmeasured confounders. Conclusion: Clinically significant arrhythmias showed strong diurnal patterns with a maximal peak between 12:00 AM and 5:59 AM and noon. Although overall arrhythmia rates were similar, the peak rate occurred overnight in individuals without heart failure and during the morning in individuals with heart failure. Further exploration of the influence of circadian rhythm on arrhythmia in the setting of hemodialysis is needed.

Arrhythmias occur with a high frequency in individuals with kidney failure. We sought to understand whether there were diurnal patterns for common types of arrhythmias in individuals with kidney failure. We used continuous rhythm data from 66 individuals on dialysis with implantable loop recorders. We found that clinically significant arrhythmias including bradycardia primarily occur overnight and in the early morning, whereas atrial fibrillation is more evenly distributed during the day.

Representation of Racial and Ethnic Minorities in Nephrology Clinical Trials: A Systematic Review and Meta-Analysis.

SIGNIFICANCE STATEMENT: Racial and ethnic disparities in clinical trial enrollment are well described. However, whether these disparities are present in nephrology randomized clinical trials has not been previously reported. We performed a systematic review and meta-analysis of 380 randomized clinical trials involving different aspects of kidney disease published between 2000 and 2021. Our results indicate that worldwide reporting of race and ethnicity is poor and that White individuals account for most of the randomized participants with decreased enrollment of Black participants in more recent trials. However, trials conducted in the United States have representation of Black and Hispanic participants consistent with the population prevalence of disease and under-representation of Asian participants. BACKGROUND: Under-representation of racial and ethnic minorities in clinical trials could worsen disparities, but reporting and enrollment practices in nephrology randomized clinical trials have not been described. METHODS: PubMed was searched to capture randomized clinical trials for five kidney disease-related conditions published between 2000 and 2021 in ten high-impact journals. We excluded trials with <50 participants and pilot trials. Outcomes of interest were the proportion of trials reporting race and ethnicity and the proportions of enrolled participants in each race and ethnicity category. RESULTS: Among 380 trials worldwide, race was reported in just over half and ethnicity in 12%. Most enrolled participants were White, and Black individuals accounted for ≤10% of participants except in dialysis trials where they accounted for 26% of participants. However, Black participants were enrolled at high proportions relative to disease and population prevalence in US CKD, dialysis, and transplant trials representing 19% of participants in AKI, 26% in CKD, 44% in GN, 40% in dialysis, and 26% in transplant trials. Enrollment of Asian participants was low worldwide except in GN trials with marked under-representation in US CKD, dialysis, and transplant trials. Hispanic individuals represented only 13% of participants in US dialysis trials compared with 29% of US dialysis population. CONCLUSION: More complete reporting of race and ethnicity in nephrology trials is needed. Black and Hispanic patients are well-represented in kidney disease trials in the United States. Asian patients are poorly represented in kidney trials both globally and in the United States.

Deep Learning Using Electrocardiograms in Patients on Maintenance Dialysis.

Cardiovascular morbidity and mortality occur with an extraordinarily high incidence in the hemodialysis-dependent end-stage kidney disease population. There is a clear need to improve identification of those individuals at the highest risk of cardiovascular complications in order to better target them for preventative therapies. Twelve-lead electrocardiograms are ubiquitous and use inexpensive technology that can be administered with minimal inconvenience to patients and at a minimal burden to care providers. The embedded waveforms encode significant information on the cardiovascular structure and function that might be unlocked and used to identify at-risk individuals with the use of artificial intelligence techniques like deep learning. In this review, we discuss the experience with deep learning-based analysis of electrocardiograms to identify cardiovascular abnormalities or risk and the potential to extend this to the setting of dialysis-dependent end-stage kidney disease.

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.

Platelet Activity and Cardiovascular Risk in CKD and Peripheral Artery Disease.

Introduction: Platelet dysfunction and cardiovascular risk are well-recognized features of chronic kidney disease (CKD). Platelets drive the development and progression of cardiovascular disease (CVD). The relationships between kidney function, platelet activity, and cardiovascular risk are poorly defined. Methods: We compared platelet activity and incident cardiovascular events by CKD status (estimated glomerular filtration rate [eGFR] < 60 ml/min per 1.73 m2) using data from the Platelet Activity and Cardiovascular Events study, a prospective cohort study that enrolled adults with peripheral artery disease (PAD) undergoing lower extremity revascularization. Platelet activity was measured using light transmission aggregometry (LTA) in response to submaximal dose agonist stimulation, and the subjects were followed for incident adverse cardiovascular events for a median of 18 months. Results: Overall, 113 of 285 (40%) subjects had CKD. Subjects with, versus without, CKD had higher platelet aggregation in response to stimulation with adenosine diphosphate (ADP), serotonin, epinephrine, and arachidonic acid (AA) + ex vivo aspirin (P < 0.05 for each). Following multivariable adjustment, subjects with CKD had elevated risk for myocardial infarction (MI) (adjusted hazard ratio 2.2, 95% confidence interval [1.02-4.9]) and major adverse cardiovascular events (MACE) (1.9 [1.2-3.3]) compared to those without CKD. Platelet aggregation in response to submaximal dose agonist stimulation mediated 7% to 26% of the excess risk for cardiovascular events associated with CKD. Conclusion: Among subjects with PAD undergoing lower extremity revascularization, CKD is associated with increased platelet activity that mediates, in part, elevated cardiovascular risk.

The Relationship between Rate and Volume of Intravenous Fluid Administration and Kidney Outcomes after Angiography.

BACKGROUND AND OBJECTIVES: Contrast-associated AKI may result in higher morbidity and mortality. Intravenous fluid administration remains the mainstay for prevention. There is a lack of consensus on the optimal administration strategy. We studied the association of periprocedure fluid administration with contrast-associated AKI, defined as an increase in serum creatinine of at least 25% or 0.5 mg/dl from baseline at 3-5 days after angiography, and 90-day need for dialysis, death, or a 50% increase in serum creatinine. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted a secondary analysis of 4671 PRESERVE participants who underwent angiographic procedures. Although fluid type was randomized, strategy of administration was at the discretion of the clinician. We divided the study cohort into quartiles by total fluid volume. We performed multivariable logistic regression, adjusting for clinically important covariates. We tested for the interaction between fluid volume and duration of fluid administration, categorized as <6 or ≥6 hours. RESULTS: The mean (SD) age was 70 (8) years, 94% of participants were male, and median (interquartile range) eGFR was 60 (41-60) ml/min per 1.73 m2. The range of fluid administered was 89-882 ml in quartile 1 and 1258-2790 ml in quartile 4. Compared with the highest quartile (quartile 4) of fluid volume, we found a significantly higher risk of the primary outcome in quartile 1 (adjusted odds ratio, 1.58; 95% confidence interval, 1.06 to 2.38) but not in quartiles 2 and 3 compared with quartile 4. There was no difference in the incidence of contrast-associated AKI across the quartiles. The interaction between volume and duration was not significant for any of the outcomes. CONCLUSIONS: We found that administration of a total volume of 1000 ml, starting at least 1 hour before contrast injection and continuing postcontrast for a total of 6 hours, is associated with a similar risk of adverse outcomes as larger volumes of intravenous fluids administered for periods >6 hours. Mean fluid volumes <964 ml may be associated with a higher risk for the primary outcome, although residual confounding cannot be excluded.

Hydralazine-Isosorbide Dinitrate Use in Patients With End-Stage Kidney Disease on Dialysis.

Introduction: The combination of hydralazine-isosorbide dinitrate (H-ISDN) has potential as a heart failure (HF) therapy in the setting of maintenance dialysis. Methods: In this retrospective study, we analyzed the efficacy of H-ISDN using United States Renal Data System (USRDS) data. We identified all adult patients with a history of HF on maintenance dialysis between January 1, 2011, and December 31, 2016, with at least 1 prescription for H-ISDN. Baseline characteristics, prescriptions, and outcomes were retrieved from institutional and physician claims. The primary outcome was death from any cause. Additional outcomes included cardiovascular death, sudden cardiac death, hospitalization for HF, an inpatient diagnosis of myocardial infarction (MI), or new-onset atrial fibrillation. Stabilized inverse probability weights were estimated using relevant baseline characteristics and were used in Cox proportional hazards regression. Results: We identified 6306 patients who were treated with H-ISDN and 75,509 patients who did not receive H-ISDN. The crude all-cause mortality rate was lower in patients treated with H-ISDN (16.0 events/100 patient years [PYs]) than in nonusers (27.9/100-PY). H-ISDN use was independently associated with lower mortality: hazard ratio (HR) 0.48 (95% CI 0.43-0.54). Cardiovascular death and sudden cardiac death were less common among H-ISDN users than nonusers, Weighted HR was 0.62 (95% CI 0.53-0.71) and 0.62 (95% CI 0.52-0.73), respectively. In contrast, HF admission and MI were more frequent in patients treated with H-ISDN (195.5 and 18.0 events/100-PY) compared with nonusers (73.4 and 10.2 events/100-PY). Conclusion: H-ISDN therapy may improve cardiovascular outcomes in maintenance dialysis patients with HF.

Utilization of Palliative Care for Patients with COVID-19 and Acute Kidney Injury during a COVID-19 Surge.

BACKGROUND AND OBJECTIVES: AKI is a common complication of coronavirus disease 2019 (COVID-19) and is associated with high mortality. Palliative care, a specialty that supports patients with serious illness, is valuable for these patients but is historically underutilized in AKI. The objectives of this paper are to describe the use of palliative care in patients with AKI and COVID-19 and their subsequent health care utilization. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted a retrospective analysis of New York University Langone Health electronic health data of COVID-19 hospitalizations between March 2, 2020 and August 25, 2020. Regression models were used to examine characteristics associated with receiving a palliative care consult. RESULTS: Among patients with COVID-19 (n=4276; 40%), those with AKI (n=1310; 31%) were more likely than those without AKI (n=2966; 69%) to receive palliative care (AKI without KRT: adjusted odds ratio, 1.81; 95% confidence interval, 1.40 to 2.33; P<0.001; AKI with KRT: adjusted odds ratio, 2.45; 95% confidence interval, 1.52 to 3.97; P<0.001), even after controlling for markers of critical illness (admission to intensive care units, mechanical ventilation, or modified sequential organ failure assessment score); however, consults came significantly later (10 days from admission versus 5 days; P<0.001). Similarly, 66% of patients initiated on KRT received palliative care versus 37% (P<0.001) of those with AKI not receiving KRT, and timing was also later (12 days from admission versus 9 days; P=0.002). Despite greater use of palliative care, patients with AKI had a significantly longer length of stay, more intensive care unit admissions, and more use of mechanical ventilation. Those with AKI did have a higher frequency of discharges to inpatient hospice (6% versus 3%) and change in code status (34% versus 7%) than those without AKI. CONCLUSIONS: Palliative care was utilized more frequently for patients with AKI and COVID-19 than historically reported in AKI. Despite high mortality, consultation occurred late in the hospital course and was not associated with reduced initiation of life-sustaining interventions. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2022_02_24_CJN11030821.mp3.

Baroreceptor Sensitivity in Individuals with CKD and Heart Failure.

Background: Heart failure is the most common cardiovascular complication of chronic kidney disease (CKD) and foreshadows a high morbidity and mortality rate. Baroreflex impairment likely contributes to cardiovascular mortality. We aimed to study the associations between CKD, heart failure, and baroreflex sensitivity (BRS) and their association with cardiovascular outcomes. Methods: We retrospectively analyzed data from a cohort of 247 individuals with moderate to severe HF. All subjects underwent BRS measurements after intravenous phenylephrine along with electrocardiography, echocardiography, and laboratory measurements. We used logistic regression models to assess the association of CKD (estimated glomerular filtration rate <60 ml/min per 1.73 m2) with BRS using iterative models. Cox proportional hazards models were used to assess associations of binary BRS and subgroups according to categorizations of CKD and BRS with cardiovascular mortality. Results: Median eGFR among individuals with CKD was 52 (IQR 44-56) ml/min per 1.73 m2. eGFR was lower in those with depressed BRS (65 [IQR 54-76] ml/min per 1.73 m2) compared with those with preserved BRS (73 [IQR 64-87] ml/min per 1.73 m2; P≤0.001). The majority of individuals with CKD had depressed BRS compared with those without CKD (60% versus 29%; P=0.05). In regression models, CKD and BRS were independently associated. Cardiovascular mortality was significantly increased in individuals with or without CKD and depressed BRS compared with those with preserved BRS and CKD. Conclusions: Cardiac BRS is depressed in patients with mild to moderate CKD and HF and associated with cardiovascular mortality. Additional study to confirm its contribution to cardiovascular mortality, particularly in advanced CKD, is warranted.

Case series of acute peritoneal dialysis in the prone position for acute kidney injury during the Covid-19 pandemic: Prone to complications?

Patients with kidney failure and acute respiratory distress syndrome (ARDS) requiring prone position have not been candidates for peritoneal dialysis (PD) due to concern with increased intra-abdominal pressure, reduction in respiratory system compliance and risks of peritoneal fluid leaks. We describe our experience in delivering acute PD during the surge in Covid-19 acute kidney injury (AKI) in the subset of patients requiring prone positioning. All seven patients included in this report were admitted to the intensive care unit with SARS-CoV-2 infection leading to ARDS, AKI and multisystem organ failure. All required renal replacement therapy, and prone positioning to improve ventilation/perfusion mismatch. All seven were able to continue PD despite prone positioning without any detrimental effects on respiratory mechanics or the need to switch to a different modality. Fluid leakage was noted in 71% of patients, but mild and readily resolved. We were able to successfully implement acute PD in ventilator-dependent prone patients suffering from Covid-19-related AKI. This required a team effort and some modifications in the conventional PD prescription and delivery.

Cardiovascular autonomic nervous system dysfunction in chronic kidney disease and end-stage kidney disease: disruption of the complementary forces.

PURPOSE OF REVIEW: Several nontraditional risk factors have been the focus of research in an attempt to understand the disproportionately high cardiovascular morbidity and mortality in chronic kidney disease (CKD) and end-stage kidney disease (ESKD) populations. One such category of risk factors is cardiovascular autonomic dysfunction. Its true prevalence in the CKD/ESKD population is unknown but existing evidence suggests it is common. Due to lack of standardized diagnostic and treatment options, this condition remains undiagnosed and untreated in many patients. In this review, we discuss current evidence pointing toward the role of autonomic nervous system (ANS) dysfunction in CKD, building off of crucial historical evidence and thereby highlighting the areas in need for future research interest. RECENT FINDINGS: There are several key mediators and pathways leading to cardiovascular autonomic dysfunction in CKD and ESKD. We review studies exploring the mechanisms involved and discuss the current measurement tools and indices to evaluate the ANS and their pitfalls. There is a strong line of evidence establishing the temporal sequence of worsening autonomic function and kidney function and vice versa. Evidence linking ANS dysfunction and arrhythmia, sudden cardiac death, intradialytic hypotension, heart failure and hypertension are discussed. SUMMARY: There is a need for early recognition and referral of CKD and ESKD patients suspected of cardiovascular ANS dysfunction to prevent the downstream effects described in this review.There are many unknowns in this area and a clear need for further research.

Point-of-care ultrasound in nephrology.

PURPOSE OF REVIEW: The use of POCUS has grown tremendously with the introduction of innovative, easy-to-carry and maneuver hand-held devices. This review focuses on nephrology-centric applications of POCUS that can be incorporated on a daily basis to make impactful and prompt clinical decisions. RECENT FINDINGS: We review articles covering use of POCUS in the dialysis unit, the Emergency Department, office, and ICU for assessment of volume status, access issues, stones, obstruction, and to help manage patients with AKI, shock, and heart failure. SUMMARY: POCUS is a welcome addition to our bedside diagnostic armamentarium and has great utility in nephrology. Trials are ongoing in evaluating outcomes with POCUS and physicians' clinical experience using it has been extremely positive.