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

The Frequency, Causes and Patterns of Asymptomatic Cardiac Arrhythmias in Patients on Maintenance Hemodialysis

Background

The knowledge of the incidence of non-severe and clinically significant arrhythmias is limited in patients with chronic kidney disease (CKD). The present study was conducted to determine the incidence, pattern and identify the factors predisposing to cardiac arrhythmias in patients on maintenance hemodialysis.

Materials and Methods

Forty-five patients were included in this prospective observational study conducted between June 2020 and November 2021. Patients ≥ 18 years of age on maintenance hemodialysis (three times/week for at least three months), with no intercurrent illness, uremic symptoms, and not hospitalized in the previous 3 months were included. Demographic and clinical characteristics of the patients were noted. Arrhythmias were recorded by attaching the Holter machine to all study patients undergoing hemodialysis. We estimated the incidence, identified the pattern of cardiac arrhythmias, and explored the factors predisposing to cardiac arrhythmias.

Results

Premature atrial complexes (17.8%), premature ventricular complexes (31.1%), ventricular bigeminy (8.9%), trigeminy (8.9%), and ventricular couplets (22.2%) were observed. The patients with hyperparathyroidism, hyper/hypomagnesemia, and poor blood pressure control had significantly higher percentages of total and ventricular arrhythmias. The patients with hypomagnesemia, reduced left ventricular ejection fraction (<50%), poor blood pressure control, and receiving statins had significantly higher percentages of atrial arrhythmias. There was no statistically significant association between age, gender, diabetes mellitus, ischaemic heart disease, interdialytic weight gain, dialysis vintage, low hemoglobin, serum calcium levels, serum potassium levels, presence of left ventricular hypertrophy, pulmonary hypertension, and diastolic dysfunction with arrhythmias.

Conclusion

A high incidence of cardiac arrhythmias was noted among patients on hemodialysis.

The impact of end-stage kidney disease on hospitalization outcomes in patients with complete heart block: insights from united states population data

INTRODUCTION

Patients with end stage kidney disease (ESKD) suffer higher rates of mortality, partly because of cardiac conduction abnormalities. Despite this, data on complete heart block (CHB) cases in patients with ESKD remain limited.

METHODS

Admissions for CHB were identified in the 2016-2019 National Inpatient Sample. In-hospital outcomes were compared between patients with and without ESKD. The primary outcome was mortality. Secondary outcomes included, Permanent Pacemaker (PPM) and Temporary Pacemaker (TPM) use, palliative care, vasopressor use, mechanical ventilation use, length of stay (LOS), and total charges. Multivariable regression models were used to adjust for confounders.

RESULTS

Among 150,265 hospitalizations with a primary diagnosis of CHB, 5,109 (3.4%) had a diagnosis of ESKD. ESKD was associated with higher odds of mortality (adjusted Odds Ration [aOR] 1.54, 95% CI 1.15-2.07), vasopressors use (aOR 1.9, 95% CI 1.25-2.88), mechanical ventilation (aOR 1.26, 95% CI 1.03-1.56), palliative care (aOR 1.41, 95% CI 1.03-1.94), TPM use (aOR 1.26, 95% CI 1.09-1.47), lower odds of PPM use (aOR 0.54, 95% CI 0.47-0.62), longer LOS (+ 1.29 days, p < 0.001) and higher charges ($123,110 vs. $87,235, p < 0.001).

CONCLUSION

Patients with ESKD admitted for CHB had higher fatal and non-fatal adverse outcomes compared to patients without ESKD.

Type of arrhythmias and the risk of sudden cardiac death in dialysis patients: a systematic review and meta-analysis

BACKGROUND

Patients on long-term dialysis for end-stage kidney disease have a high mortality rate, predominantly due to sudden cardiac death (SCD), which is associated with an increased risk of arrhythmias compared to the general population. Thus, the current systematic review and meta-analysis aimed to investigate the incidence of SCD among dialysis patients at risk of arrhythmia.

METHODS

This systematic review and meta-analysis followed the PRISMA guidelines. PubMed, Cochrane Library, Google Scholar, Medline, and Europe PMC were searched for articles meeting our inclusion criteria. Studies with risk assessment of arrhythmias and the incidence of SCD in dialysis patients were considered for inclusion. Effect size from eligible studies was pooled using a random effects model and restricted maximum likelihood estimation. Heterogeneity was quantified using the I2 statistic, and the risk of publication bias was evaluated by visually inspecting funnel plots.

RESULTS

Our search strategy yielded 5861 studies, of which 1960 duplicate entries were removed in the prescreening stage, 3326 were excluded after title/abstract screening, and 519 after full-text screening for not meeting our inclusion criteria. Finally, 11 studies were included in the analysis, and two more were selected from the bibliography list of previous reviews. Eight included studies were randomized controlled trials, and five were cohort studies, which provided a pooled population size of 12,611 dialysis patients for the meta-analysis, which indicated a significantly larger effect size of arrhythmia [Cohen's d = 110.38 (95%CI 42.72-178.05), p = 0.0]. Visual assessment of the funnel plot indicated no publication bias.

CONCLUSION

SCD remains a significant public health concern, particularly in patients undergoing dialysis. Meta-analysis results show that bradyarrhythmia is a common arrhythmic condition leading to SCD; however, other arrhythmias should also be considered.

Cardiomyopathy in chronic kidney disease: clinical features, biomarkers and the contribution of murine models in understanding pathophysiology

The cardiorenal syndrome (CRS) is described as a multi-organ disease encompassing bidirectionally heart and kidney. In CRS type 4, chronic kidney disease (CKD) leads to cardiac injury. Different pathological mechanisms have been identified to contribute to the establishment of CKD-induced cardiomyopathy, including a neurohormonal dysregulation, disturbances in the mineral metabolism and an accumulation of uremic toxins, playing an important role in the development of inflammation and oxidative stress. Combined, this leads to cardiac dysfunction and cardiac pathophysiological and morphological changes, like left ventricular hypertrophy, myocardial fibrosis and cardiac electrical changes. Given that around 80% of dialysis patients suffer from uremic cardiomyopathy, the study of cardiac outcomes in CKD is clinically highly relevant. The present review summarizes clinical features and biomarkers of CKD-induced cardiomyopathy and discusses underlying pathophysiological mechanisms recently uncovered in the literature. It discloses how animal models have contributed to the understanding of pathological kidney-heart crosstalk, but also provides insights into the variability in observed effects of CKD on the heart in different CKD mouse models, covering both "single hit" as well as "multifactorial hit" models. Overall, this review aims to support research progress in the field of CKD-induced cardiomyopathy.

Diagnosis of cardiovascular disease in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) are at high risk of cardiovascular disease (CVD) and cardiovascular death. Identifying and monitoring cardiovascular complications and hypertension is important for managing patients with CKD or kidney failure and transplant recipients. Biomarkers of myocardial ischaemia, such as troponins and electrocardiography (ECG), have limited utility for diagnosing cardiac ischaemia in patients with advanced CKD. Dobutamine stress echocardiography, myocardial perfusion scintigraphy and dipyridamole stress testing can be used to detect coronary disease in these patients. Left ventricular hypertrophy and left ventricular dysfunction can be detected and monitored using various techniques with differing complexity and cost, including ECG, echocardiography, nuclear magnetic resonance, CT and myocardial scintigraphy. Atrial fibrillation and other major arrhythmias are common in all stages of CKD, and ambulatory heart rhythm monitoring enables precise time profiling of these disorders. Screening for cerebrovascular disease is only indicated in asymptomatic patients with autosomal dominant polycystic kidney disease. Standardized blood pressure is recommended for hypertension diagnosis and treatment monitoring and can be complemented by ambulatory blood pressure monitoring. Judicious use of these diagnostic techniques may assist clinicians in detecting the whole range of cardiovascular alterations in patients with CKD and enable timely treatment of CVD in this high-risk population.

Association of serum electrolyte changes during haemodialysis with stimulation of premature ventricular contractions

Background

Patients on haemodialysis are predisposed to heart rhythm disorders, including bradyarrhythmia, atrial fibrillation (AF)/atrial flutter, supraventricular/ventricular arrhythmias and sudden cardiac death (SCD) (Turakhia et al. in Eur Heart J 39:2314–2325, 2018). In addition to the fact that patients on haemodialysis have a high prevalence of underlying cardiac disease, the stress of haemodialysis itself might also contribute to increased rates of arrhythmias and SCD (Samanta et al. in Can J Cardiol 35:1228–1240, 2019).

Methods

A Holter 24-h electrocardiogram was set up immediately before the start of haemodialysis for 72 haemodialysis patients (dialysis vintage: 6–8734 days) to record premature ventricular contractions (PVCs) as a marker of arrhythmogenesis for 24 h. Blood samples were also collected every hour during haemodialysis treatment. Each patient was dialyzed against a dialysate consisting of Na+140 mEq/L, K+ 2.0 mEq/L, Ca+ 3.0 mEq/L, Mg2+ 1.0 mEq/L, Cl− 110 mEq/L, CH3COO− 8 mmol/L and HCO3− 30 mEq/L.

Results

The frequency of PVCs significantly increased in the 4th (80 ± 34 beats/hour, mean ± S.E.), 5th (79 ± 31 beats/hour) and 6th (105 ± 36 beats/hour) hours (F = 5.24, p < 0.00001, n = 72). The lowest left ventricular ejection fraction (LVEF, p = 0.001) and the highest b-type natriuretic peptide (BNP) levels (p = 0.049) were found in patients with the highest PVC counts. There was an association of positive changes in both serum K+ (β ± S.E., 9.7 ± 2.4, p = 0.0002), Mg2+ (43.2 ± 10.3, p = 0.0001) and HCO3− (5.3 ± 1.8, p = 0.005) with the frequency of PVCs for 4 h immediately after dialysis. During the same period, there was an association of lower serum K+ (− 8.37 ± 2.16, p = 0.0003) and higher Ca2+ (73.4 ± 18.0, p = 0.0002) with the frequency of PVCs.

Conclusions

Haemodialysis stimulated PVC generation, and this effect was especially prominent during the period immediately after haemodialysis. Some serum electrolyte changes affected this PVC stimulation. A positive change in serum K+ or Mg2+ and a negative change in serum Ca2+ during dialysis are risk factors for stimulating PVCs, particularly in patients with lower serum K+ or higher serum Ca2+ levels at the start of dialysis.

Frequency and type of arrhythmia in Holter electrocardiogram in patients undergoing hemodialysis

Background/Aim: It is known that approximately 40% of chronic hemodialysis patients die due to cardiac arrhythmia and cardiovascular reasons. Determining whether the hemodialysis procedure poses a risk for arrhythmia is important in terms of prognostic follow-up of the patients. Therefore, we aimed to determine the underlying arrhythmia frequency and types with 24-hour Holter electrocardiogram (ECG) in patients receiving hemodialysis with normal baseline electrocardiography between the hemodialysis periods. Methods: Between January 2018 and January 2022, 91 consecutive patients who received hemodialysis for chronic renal failure (CRF) and applied to the cardiology outpatient clinic with complaints of palpitation and sinus rhythm on ECG and evaluated with 24-hour rhythm Holter ECG were included in the study. Our study was designed as a retrospective cohort study. Results: The mean age of the patient population was 65.78 (11.92) years, the mean systolic blood pressure was 143.71 (24.88) mmHg, and the mean heart rate was 83.43 (15.85) beats/min. Hypertension (HT) (n=44, 48%) and coronary artery disease (n=34, 37%) were the most common comorbid diseases. The most common arrhythmias detected on Holter ECG were ventricular extrasystole (VES) (n=18, 19.8%) and paroxysmal AF (n=8, 8.8%). Non-sustained ventricular tachycardia was detected in two patients. Conclusion: Detecting arrhythmia in the interdialytic periods in patients receiving hemodialysis due to CRF is important for follow-up and treatment. Even if the baseline ECG is normal in hemodialysis patients with CRF, the frequency of the underlying arrhythmia that needs to be treated is high.

Arrhythmia and Heart Rate Variability during Long Interdialytic Periods in Patients on Maintenance Hemodialysis: Prospective Observational Cohort Study

Sudden cardiac death among hemodialysis patients is related to the hemodialysis schedule. Mortality is highest within 12 h before and after the first hemodialysis sessions of a week. We investigated the association of arrhythmia occurrence and heart rate variability (HRV) using an electrocardiogram (ECG) monitoring patch during the long interdialytic interval in hemodialysis patients. This was a prospective observational study with 55 participants on maintenance hemodialysis for at least six months. A patch-type ECG monitoring device was applied to record arrhythmia events and HRV during 72 h of a long interdialytic period. Forty-nine participants with sufficient ECG data out of 55 participants were suitable for the analysis. The incidence of supraventricular tachycardia and ventricular tachycardia did not significantly change over time. The square root of the mean squared differences of successive NN intervals (RMSSD), the proportion of adjacent NN intervals differing by >50 ms (pNN50), and high-frequency (HF) increased during the long interdialytic interval. The gap in RMSSD, pNN50, HF, and the low-frequency/high-frequency (LF/HF) ratio between patients with and without significant arrhythmias increased significantly over time during the long interdialytic interval. The daily changes in RMSSD, pNN50, HF, and the LF/HF ratio were more prominent in patients without significant arrhythmias than in those with significant arrhythmias. The electrolyte fluctuation between post-hemodialysis and subsequent pre-hemodialysis was not considered in this study. The study results suggest that the decreased autonomic response during interdialytic periods in dialysis patients is associated with poor cardiac arrhythmia events.

Readmission rates and risk factors for readmission after transcatheter aortic valve replacement in patients with end-stage renal disease

Objectives

We sought to examine readmission rates and predictors of hospital readmission following TAVR in patients with ESRD.

Background

End-stage renal disease (ESRD) is associated with poor outcomes following transcatheter aortic valve replacement (TAVR).

Methods

We assessed index hospitalizations for TAVR from the National Readmissions Database from 2017 to 2018 and used propensity scores to match those with and without ESRD. We compared 90-day readmission for any cause or cardiovascular cause. Length of stay (LOS), mortality, and cost were assessed for index hospitalizations and 90-day readmissions. Multivariable logistic regression was performed to identify predictors of 90-day readmission.

Results

We identified 49,172 index hospitalizations for TAVR, including 1,219 patients with ESRD (2.5%). Patient with ESRD had higher rates of all-cause readmission (34.4% vs. 19.2%, HR 1.96, 95% CI 1.68–2.30, p<0.001) and cardiovascular readmission (13.2% vs. 7.7%, HR 1.85, 95% CI 1.44–2.38, p<0.001) at 90 days. During index hospitalization, patients with ESRD had longer length of stay (mean difference 1.9 days), increased hospital cost (mean difference $42,915), and increased in-hospital mortality (2.6% vs. 0.9%). Among those readmitted within 90 days, patients with ESRD had longer LOS and increased hospital charge, but similar in-hospital mortality. Diabetes (OR 1.86, 95% CI 1.31–2.64) and chronic pulmonary disease (OR 1.51, 95% CI 1.04–2.18) were independently associated with higher odds of 90-day readmission in patients with ESRD.

Conclusion

Patients with ESRD undergoing TAVR have higher mortality and increased cost associated with their index hospitalization and are at increased risk of readmission within 90 days following TAVR.

Prognostic value of cardiac troponin in dialysis patients with paroxysmal supraventricular tachycardia

A rise in cardiac troponin I (cTnI) is common in supraventricular tachycardia (SVT). While troponin elevation in SVT is thought to be a predictor of future adverse events in patients with prior coronary artery disease, the prognostic significance of cTnI in end-stage kidney disease (ESKD) patients with SVT are not known. We aimed to examine the prognostic significance of cTnI in ESKD patients presenting with SVT in the emergency department. This was a retrospective, multiple-center observational study utilizing regularly collected electronic medical records. We screened electronic medical records of all dialysis patients presenting to the emergency departments in 5 hospitals over 12 years with SVT. These patients were divided into whether cTnI was tested, and were further stratified into the cTnI-positive and cTnI-negative groups. The primary outcome of the study was the 3-year risk of major adverse cardiovascular events (MACE). Sixty-two patients were qualified for inclusion. Fifty-seven patients (91.9%) were tested for cTnI, and 5 patients were not. Patients with the cTnI test were older (P = .03) and had a longer length of hospital stay (P < .001). Forty-seven patients (82.5%) had a positive result, and 10 (17.5%) had a negative result. A history of hypertension (P = .013) and decreased left ventricular ejection fraction (P = .048) were the independent predictors of cTnI elevation. After a mean follow-up period of 20.6 ± 14.7 months, there were no differences in 3-year MACE between patients with or without elevated cTnI levels in Kaplan-Meier analysis (P = .34). A history of coronary artery disease was the only independent predictor of 3-year MACE (P = .017). Through the subgroup analysis, a history of coronary artery disease (HR 2.73; CI 1.01-7.41; P = .049) remained an independent risk factor for 3-year MACE in patients with elevated cTnI levels. A large proportion (82.5%) of troponin elevation was observed in ESKD patients with SVT, but it had a poor correlation with MACE.

Left atrial reservoir strain is an outstanding predictor of adverse cardiovascular outcomes in patients undergoing maintenance hemodialysis: Assessment via three-dimensional speckle tracking echocardiography

Background

There is a paucity of literature focusing left atrium (LA) in patients undergoing maintenance hemodialysis (MHD).

Hypothesis

We used three‐dimensional speckle tracking echocardiography (3DSTE) to evaluate LA in MHD patients and to explore its predictive value for adverse outcomes.

Methods

Echocardiography was performed on 130 consecutively enrolled MHD patients without previous cardiac diseases. Conventional and 3DSTE parameters of LA were obtained. The MHD cohort was then followed and the end point was major adverse cardiovascular events (MACEs). LA strain indices, including reservoir strain (LASr), conduit strain (LAScd), and contractile strain (LASct), were measured and compared between patients with and without MACEs.

Results

Patients were prospectively followed up for a median of 40.5 (interquartile range: 26.3–48.0) months. During follow‐up, 43 patients met the end point. These patients had larger LA size and reduced LA strains (LA maximal volume indexed: 45.1 ± 11.9 vs. 33.8 ± 6.9ml/m²; LASr: 20.2 ± 3.5 vs. 27.2 ± 3.3%; LAScd: −12.3 ± 5.2 vs. −14.5±4.0%; LASct: −8.0 ± 4.2 vs. −13.2 ± 3.7%; all p<.05), compared with those without MACEs. Multivariable regression analysis showed LASr was the strongest predictor of MACEs (hazard ratio, 0.69; 95% confidence interval, 0.54–0.89; p=.004). Univarite Kaplan–Meier analysis revealed the incidence of MACEs in the impaired LASr (<24.2%) group was significantly higher than in the normal LASr group (log rank p<.001).

Conclusions

LASr derived from 3DSTE is an independent predictor of MACEs and cardiac death in MHD patients, superior to LV parameters and LA volume indices.

Fibroblast Growth Factor-23-Klotho Axis in Cardiorenal Syndrome: Mediators and Potential Therapeutic Targets

Cardiorenal syndrome (CRS) is a complex disorder that refers to the category of acute or chronic kidney diseases that induce cardiovascular disease, and inversely, acute or chronic heart diseases that provoke kidney dysfunction. There is a close relationship between renal and cardiovascular disease, possibly due to the presence of common risk factors for both diseases. Thus, it is well known that renal diseases are associated with increased risk of developing cardiovascular disease, suffering cardiac events and even mortality, which is aggravated in those patients with end-stage renal disease or who are undergoing dialysis. Recent works have proposed mineral bone disorders (MBD) as the possible link between kidney dysfunction and the development of cardiovascular outcomes. Traditionally, increased serum phosphate levels have been proposed as one of the main factors responsible for cardiovascular damage in kidney patients. However, recent studies have focused on other MBD components such as the elevation of fibroblast growth factor (FGF)-23, a phosphaturic bone-derived hormone, and the decreased expression of the anti-aging factor Klotho in renal patients. It has been shown that increased FGF-23 levels induce cardiac hypertrophy and dysfunction and are associated with increased cardiovascular mortality in renal patients. Decreased Klotho expression occurs as renal function declines. Despite its expression being absent in myocardial tissue, several studies have demonstrated that this antiaging factor plays a cardioprotective role, especially under elevated FGF-23 levels. The present review aims to collect the recent knowledge about the FGF-23-Klotho axis in the connection between kidney and heart, focusing on their specific role as new therapeutic targets in CRS.

Effects of interdialytic interval on heart rate variability in chronic hemodialysis patients: a cross-sectional study

Previous studies showed that long interdialytic interval of chronic hemodialysis increased risk of sudden cardiac death compared to short interdialytic interval. Diabetes mellitus (DM) and autonomic dysfunction are the strong adverse predictors of survival in ESRD patients. We aimed to compare autonomic function between long and short interdialytic interval of chronic hemodialysis in patients with and without DM. One-hundred sixty-three patients receiving chronic hemodialysis were enrolled. The electrocardiogram recording was performed twice in each patient during 4-h hemodialysis session after long and short interdialytic intervals to assess heart rate variability (HRV). Mean age was 61.4 ± 14.3 years. HRV parameters during hemodialysis did not differ between long and short interdialytic interval in overall population. Nevertheless, in 82 (50.3%) patients, SDNN (47.4 ± 23.8 vs. 43.4 ± 19.5 ms, P = 0.039), ASDNN (24.8 ± 14.3 vs. 22.7 ± 12.3 ms, P = 0.025), LF (8.4 ± 6.8 vs. 7.6 ± 6.6 ms², P = 0.040) increased after long interdialytic interval. The greater change of SDNN, ASDNN, VLF and LF between long and short interdialytic intervals was noted in DM, compared to non-DM patients. We demonstrated that there was no difference of HRV parameters after short and long interdialytic interval. However, there was greater autonomic alteration observed in DM than non-DM patients between 2 interdialytic intervals.

Prolongation of QTc interval at the beginning and during dialysis is associated with hypervolemia and calcium and magnesium change in the first 2 h

BACKGROUND AND AIMS

High rates of sudden cardiac death are mostly attributed to ventricular arrhythmias including QTc prolongation in hemodialysis patients. We aimed to investigate the correlation of electrolyte and volume changes with QTc interval prolongation in hemodialysis patients.

STUDY DESIGN

The present study is designed as a cross-sectional study.

METHODS

The study was conducted at the hemodialysis unit of a training and research hospital and its' satellite dialysis unit. Patients were divided into three groups. Group-1: with normal QTc interval both at the beginning and during dialysis session; group-2: with prolonged QTc interval at the beginning and remained prolonged during dialysis session; group-3: with normal QTc interval at the beginning but prolonged during the dialysis session. In addition, patients were evaluated in terms of QTc change between the beginning and 2nd hour (delta-QTc-1) and between 2nd hour and 4th hour (delta-QTc-2), respectively, and defined as 'patients with increased QTc interval' and 'patients without increased QTc interval'.

RESULTS

A total of 45 prevalent hemodialysis patients were enrolled in the study. 14 patients (31.1%) had normal QTc interval (group-1), 13 patients (28.9%) had prolonged QTc interval at the beginning and remained prolonged during dialysis session (group-2) and 18 patients (40%) had normal QTc interval at the beginning but prolonged during dialysis session (group-3). There was no statistically significant difference between groups in terms of baseline electrolyte levels. Calcium change in the first 2 h was lower in patients with QTc prolongation from the start or during the dialysis session (group-2 and group-3). In addition, systolic blood pressure (SBP) levels at the beginning of the session (118 ± 15 mmHg vs 124 ± 28 mmHg vs138 ± 24 mmHg; p = 0.04) and intradialytic ultrafiltration (UF) rate were higher (1.96 ± 0.6 L/4 h vs 2.6 ± 1.0 L/4 h vs 2.8 ± 0.9 L/4 h; p = 0.03) in group-2 and group-3 compared to patients in group-1. Increase in QTc interval was found higher in patients with less calcium increase (Rho: - 0.36; p = 0.01) and with greater magnesium decrease in the first 2 h (Rho: 0.31; p = 0.04).

CONCLUSION

QTc interval prolongation is common among hemodialysis patients. High intradialytic UF rates, change in serum magnesium and calcium levels in the first 2 h were found associated with QTc prolongation. However, QTc prolongation was found independently associated only with UF volume and calcium change in the first 2 h.

Genetic Deletion of NOD1 Prevents Cardiac Ca2+ Mishandling Induced by Experimental Chronic Kidney Disease

Risk of cardiovascular disease (CVD) increases considerably as renal function declines in chronic kidney disease (CKD). Nucleotide-binding oligomerization domain-containing protein 1 (NOD1) has emerged as a novel innate immune receptor involved in both CVD and CKD. Following activation, NOD1 undergoes a conformational change that allows the activation of the receptor-interacting serine/threonine protein kinase 2 (RIP2), promoting an inflammatory response. We evaluated whether the genetic deficiency of Nod1 or Rip2 in mice could prevent cardiac Ca²⁺ mishandling induced by sixth nephrectomy (Nx), a model of CKD. We examined intracellular Ca²⁺ dynamics in cardiomyocytes from Wild-type (Wt), Nod1^-/- and Rip2^-/- sham-operated or nephrectomized mice. Compared with Wt cardiomyocytes, Wt-Nx cells showed an impairment in the properties and kinetics of the intracellular Ca²⁺ transients, a reduction in both cell shortening and sarcoplasmic reticulum Ca²⁺ load, together with an increase in diastolic Ca²⁺ leak. Cardiomyocytes from Nod1^-/--Nx and Rip2^-/--Nx mice showed a significant amelioration in Ca²⁺ mishandling without modifying the kidney impairment induced by Nx. In conclusion, Nod1 and Rip2 deficiency prevents the intracellular Ca²⁺ mishandling induced by experimental CKD, unveiling new innate immune targets for the development of innovative therapeutic strategies to reduce cardiac complications in patients with CKD.

Trends in Cardiovascular Mortality Among a Cohort of Children and Young Adults Starting Dialysis in 1995 to 2015

IMPORTANCE

Survival of patients receiving dialysis has improved during the last 2 decades. However, few studies have examined temporal trends in the attributed causes of death (especially cardiovascular-related) in young populations.

OBJECTIVE

To determine temporal trends and risk of cause-specific mortality (ie, cardiovascular and infectious) for children and young adults receiving dialysis.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study examined the records of children and young adults (aged <30 years) starting dialysis between 1995 and 2015 according to the United States Renal Data System database. Analyses were performed between June 2019 and June 2020. Fine-Gray models were used to examine trends in risk of different cardiovascular-related deaths. Models were adjusted for age, sex, race, neighborhood income, cause of end-stage kidney disease, insurance type, and comorbidities. Analyses were performed separately for children (ie, age <18 years) and young adults (between ages 18 and 30 years). Follow-up was censored at death or administratively, and transplantation was treated as a competing event.

EXPOSURES

Calendar year.

MAIN OUTCOMES AND MEASURES

Cardiovascular cause-specific mortality.

RESULTS

A total of 80 189 individuals (median [interquartile range] age, 24 [19-28] years; 36 259 [45.2%] female, 29 508 [36.8%] Black, and 15 516 [19.3%] Hispanic white) started dialysis and 16 179 experienced death during a median (interquartile range) of 14.3 (14.0-14.7) years of follow-up. Overall, 40.2% of deaths were from cardiovascular-related causes (6505 of 16 179 patients). In adjusted analysis, risk of cardiovascular-related death was stable initially but became statistically significantly lower after 2006 (vs 1995) in those starting dialysis as either children (subhazard ratio [SHR], 0.74; 95% CI, 0.55-1.00) or adults (SHR, 0.90; 95% CI, 0.83-0.98). Risk of sudden cardiac death improved steadily for all age groups, but to a greater degree in children (SHR, 0.31; 95% CI, 0.20-0.47) vs young adults (SHR, 0.64; 95% CI, 0.56-0.73) comparing 2015 vs 1995. Risk of stroke became statistically significantly lower around 2010 (vs 1995) for children (SHR, 0.40; 95% CI, 0.18-0.88) and young adults (SHR, 0.76; 95% CI, 0.59-0.99).

CONCLUSIONS AND RELEVANCE

In this study, the risk of cardiovascular-related death declined for children and young adults starting dialysis during the last 2 decades, but trends differed depending on age at dialysis initiation and the specific cause of death. Additional studies are needed to improve risk of cardiovascular disease in young populations.