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

Hypertension and Cardiovascular Risk Among Children with Chronic Kidney Disease

PURPOSE OF REVIEW

Cardiovascular disease is the most common cause of mortality across the lifespan of children with chronic kidney disease (CKD). Hypertension is a common and important contributor, but other factors such as obesity, dyslipidemia and mineral bone disease play a role. This narrative review focusses on studies published in the past five years that have investigated hypertension and cardiovascular risk among children with CKD.

RECENT FINDINGS

Cohort studies such as Chronic Kidney Disease in Children (CKiD) and Cardiovascular Comorbidity in Children with CKD (4C) have continued to develop our understanding of blood pressure (BP) phenotypes, and of progressive changes in the structure and function of the heart and blood vessels occurring in children with CKD. Metabolic risk factors, such as dyslipidemia, may represent an under-recognized component of care. Trial data are less common than observational evidence, but support lifestyle interventions currently used, mainly the low sodium dietary approaches to stop hypertension (DASH) diet. The findings of the recently reported Hypertension Optimal Treatment in Children with Chronic Kidney Disease trial (HOT-KID) are described in relation to the use of office BP treatment targets. Cardiovascular health is critical to the long-term outcomes of children with CKD. Recognizing and treating hypertension remains a critical component to improving outcomes, along with measures to improve concurrent cardiovascular risk factors. Some cardiovascular changes may not be reversible with transplantation and further research is needed for children at all stages of CKD.

Rurality of patient residence and access to transplantation among children with kidney failure in the United States

BACKGROUND

Residence in rural areas is often a barrier to health care access. To date, differences in access to kidney transplantation among children who reside in rural and micropolitan areas of the US have not been explored.

METHODS

A retrospective cohort study of children < 18 years who developed kidney failure between 2000 and 2019 according to the United States Renal Data System (USRDS). We examined the association between rurality of patient residence and time to living and/or deceased donor kidney transplantation (primary outcomes) and waitlist registration (secondary outcome) using Fine-Gray models.

RESULTS

We included 18,530 children, of whom 14,175 (76.5%) received a kidney transplant (39.8% from a living and 60.2% from a deceased donor). Residence in micropolitan (subhazard ratio (SHR) 1.16; 95% CI 1.06-1.27) and rural (SHR 1.18; 95% CI 1.06-1.3) areas was associated with better access to living donor transplantation compared with residence in metropolitan areas. There was no statistically significant association between residence in micropolitan (SHR, 0.95; 95%CI 0.88-1.03) and rural (SHR, 0.94; 95%CI 0.86-1.03) areas compared with metropolitan areas in the access of children to deceased donor transplantation. There was also no difference in the time to waitlist registration comparing micropolitan (SHR 1.04; 95%CI 0.98-1.10) and rural (SHR 1.05; 95% CI 0.98-1.13) versus metropolitan areas.

CONCLUSIONS

In children with kidney failure, residence in rural and micropolitan areas was associated with better access to living donor transplantation and similar access to deceased donor transplantation compared with residence in metropolitan areas.

Efficacy of pre-emptive kidney transplantation for adults with end-stage kidney disease: a systematic review and meta-analysis

BACKGROUND

Pre-emptive kidney transplantation (PEKT), i.e., transplantation performed before initiation of maintenance dialysis, is considered an ideal renal replacement therapy because there is no exposure to long-term dialysis therapy. Therefore, we summarized advantages/disadvantages of PEKT to assist in deciding whether kidney transplantation should be performed pre-emptively.

METHODS

This study was registered with PROSPERO, CRD42021269163. Observational studies comparing clinical outcomes between PEKT and non-PEKT were included; those involving only pediatric recipients or simultaneous multi-organ transplantations were excluded. The PubMed/MEDLINE, Cochrane Library, and Ichushi-Web databases were searched on 1 August 2021. Studies were pooled using the generic inverse-variance method with random effects model, and risk of bias was assessed using ROBINS-I.

RESULTS

Seventy-six studies were included in the systematic review (sample size, 23-121,853; enrollment year, 1968-2019). PEKT patients had lower all-cause mortality (adjusted HR: 0.78 [95% CI 0.66-0.92]), and lower death-censored graft failure (0.81 [0.67-0.98]). Unadjusted RRs for the following outcomes were comparable between the two patient groups: cardiovascular disease, 0.90 (0.58-1.40); biopsy-proven acute rejection, 0.75 (0.55-1.03); cytomegalovirus infection, 1.04 (0.85-1.29); and urinary tract infection, 0.89 (0.61-1.29). Mean differences in post-transplant QOL score were comparable in both groups. The certainty of evidence for mortality and graft failure was moderate and that for other outcomes was very low following the GRADE classification.

CONCLUSIONS

The present meta-analysis shows the potential benefits of PEKT, especially regarding patient and graft survival, and therefore PEKT is recommended for adults with end-stage kidney disease.

Risk Factor Analysis for Long-Term Graft Survival Following Pediatric Kidney Transplantation: The Importance of Pretransplantation Time on Dialysis and Donor/Recipient Age Difference

Recognizing risk factors that may negatively affect long-term graft survival following pediatric kidney transplantation is a key element in the decision-making process during organ allocation. We retrospectively reassessed all cases of pediatric kidney transplantation performed in our center in the last 20 years with the aim of determining baseline characteristics that could be identified as prognostic risk factors for long-term graft survival. Between 2001 and 2020, a total of 91 kidney transplantations in children under the age of 18 years were undertaken in our center. Early graft failure was observed in six of the 91 patients (7%). The median follow-up of the remaining 85 children was 100 months, and the overall kidney graft survival rates at 5, 10, 15 and 20 years were 85.2%, 71.4%, 46.0% and 30.6%, respectively. Small children with a body surface area of <1 m2 were significantly associated with better long-term graft survival outcomes, while adolescents aged more than twelve years showed poorer graft survival rates than younger children. Body surface area of the recipient of ≥1 m2, pretransplantation duration of the recipient on dialysis ≥18 months, hemodialysis prior to transplantation and donor/recipient age difference of ≥25 years were significantly associated with poorer long-term graft survival.

The number of valvular insufficiency is a strong predictor of cardiovascular and all-cause mortality in hemodialysis patients

OBJECTIVES

To investigate the relationship between the number of valvular insufficiency (VI) and emergency hospitalization or mortality in maintenance hemodialysis (HD) patients.

METHODS

The maintenance HD patients with cardiac ultrasonography were included. According to the number of VI ≥ 2 or not, the patients were divided into two groups. The difference of emergency hospitalized for acute heart failure, arrhythmia, acute coronary syndrome (ACS) or stroke, cardiovascular mortality, and all-cause mortality between the two groups were compared.

RESULTS

Among 217 maintenance HD patients, 81.57% had VI. 121 (55.76%) patients had two or more VI, and 96 (44.24%) with one VI or not. The study subjects were followed up for a median of 47 (3-107) months. At the end of the follow up, 95 patients died (43.78%), of whom 47 (21.66%) patients died because of cardiovascular disease. Age (HR 1.033, 95% CI 1.007-1.061, P = 0.013), number of VI ≥ 2 (HR 2.035, 95% CI 1.083-3.821, P = 0.027) and albumin (HR 0.935, 95% CI 0.881-0.992, P = 0.027) were independent risk factors for cardiovascular mortality. The three parameters were also independent risk factors for all-cause mortality. The patients with number of VI ≥ 2 were more likely to be emergency hospitalized for acute heart failure (56 [46.28%] vs 11 [11.46%], P = 0.001). On the contrary, the number of VI was not associated with emergency hospitalized for arrhythmia, ACS or stroke. Survival analysis results showed that probability of survival was statistically different in the two groups (P < 0.05), no matter based on cardiovascular mortality or all-cause mortality. Based on age, number of VI ≥ 2 and albumin, nomogram models for 5-year cardiovascular and all-cause mortality were built.

CONCLUSIONS

In maintenance HD patients, the prevalence of VI is prominently high. The number of VI ≥ 2 is associated with emergency hospitalized for acute heart failure, cardiovascular and all-cause mortality. Combining age, number of VI ≥ 2, and albumin can predict cardiovascular and all-cause mortality.

Association Between Dialysis Facility Ownership and Mortality Risk in Children With Kidney Failure

Importance

In adults, treatment at profit dialysis facilities has been associated with a higher risk of death.

Objective

To determine whether profit status of dialysis facilities is associated with the risk of death in children with kidney failure treated with dialysis and whether any such association is mediated by differences in access to transplant.

Design, Setting, and Participants

This retrospective cohort study reviewed US Renal Data System records of 15 359 children who began receiving dialysis for kidney failure between January 1, 2000, and December 31, 2019, in US dialysis facilities. The data analysis was performed between May 2, 2022, and June 15, 2023.

Exposure

Time-updated profit status of dialysis facilities.

Main Outcomes and Measures

Adjusted Fine-Gray models were used to determine the association of time-updated profit status of dialysis facilities with risk of death, treating kidney transplant as a competing risk. Cox proportional hazards regression models were also used to determine time-updated profit status with risk of death regardless of transplant status.

Results

The final cohort included 8465 boys (55.3%) and 6832 girls (44.7%) (median [IQR] age, 12 [3-15] years). During a median follow-up of 1.4 (IQR, 0.6-2.7) years, with censoring at transplant, the incidence of death was higher at profit vs nonprofit facilities (7.03 vs 4.06 per 100 person-years, respectively). Children treated at profit facilities had a 2.07-fold (95% CI, 1.83-2.35) higher risk of death compared with children at nonprofit facilities in adjusted analyses accounting for the competing risk of transplant. When follow-up was extended regardless of transplant status, the risk of death remained higher for children treated in profit facilities (hazard ratio, 1.47; 95% CI, 1.35-1.61). Lower access to transplant in profit facilities mediated 67% of the association between facility profit status and risk of death (95% CI, 45%-100%).

Conclusions and Relevance

Given the higher risk of death associated with profit dialysis facilities that is partially mediated by lower access to transplant, the study's findings indicate a need to identify root causes and targeted interventions that can improve mortality outcomes for children treated in these facilities.

Interleukin-6 levels can be used to estimate cardiovascular and all-cause mortality risk in dialysis patients: A meta-analysis and a systematic review

BACKGROUND

Although previous studies have explored the correlation of interleukin (IL)-6 with mortality risk in dialysis patients, the findings have been conflicting. Hence, this meta-analysis aimed to comprehensively assess the use of IL-6 measurement for estimating cardiovascular mortality and all-cause mortality in dialysis patients.

METHODS

The Embase, PubMed, Web of Science, and MEDLINE databases were searched to identify relevant studies. After screening out the eligible studies, the data were extracted.

RESULTS

Twenty-eight eligible studies with 8370 dialysis patients were included. Pooled analyses revealed that higher IL-6 levels were related to increased cardiovascular mortality risk (hazard ratio [HR] = 1.55, 95% confidence interval [CI]: 1.20-1.90) and all-cause mortality risk (HR = 1.11, 95% CI: 1.05-1.17) in dialysis patients. Further subgroup analyses suggested that higher IL-6 levels were associated with elevated cardiovascular mortality in hemodialysis patients (HR = 1.59, 95% CI: 1.36-1.81) but not in peritoneal dialysis patients (HR = 1.56, 95% CI: 0.46-2.67). Moreover, sensitivity analyses indicated that the results were robust. Egger's test revealed potential publication bias among studies exploring the correlation of IL-6 levels with cardiovascular mortality (p = .004) and all-cause mortality (p < .001); however, publication bias was not observed when using Begg's test (both p > .05).

CONCLUSIONS

This meta-analysis reveals that higher IL-6 levels could indicate higher risks of cardiovascular mortality and all-cause mortality in dialysis patients. These findings suggest that monitoring IL-6 cytokine may help to enhance dialysis management and improve the general prognosis of patients.

Cause-Specific Mortality in Patients With Advanced Chronic Kidney Disease in the ISCHEMIA-CKD Trial

BACKGROUND

In ISCHEMIA-CKD, 777 patients with advanced chronic kidney disease and chronic coronary disease had similar all-cause mortality with either an initial invasive or conservative strategy (27.2% vs 27.8%, respectively).

OBJECTIVES

This prespecified secondary analysis from ISCHEMIA-CKD (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches-Chronic Kidney Disease) was conducted to determine whether an initial invasive strategy compared with a conservative strategy decreased the incidence of cardiovascular (CV) vs non-CV causes of death.

METHODS

Three-year cumulative incidences were calculated for the adjudicated cause of death. Overall and cause-specific death by treatment strategy were analyzed using Cox models adjusted for baseline covariates. The association between cause of death, risk factors, and treatment strategy were identified.

RESULTS

A total of 192 of the 777 participants died during follow-up, including 94 (12.1%) of a CV cause, 59 (7.6%) of a non-CV cause, and 39 (5.0%) of an undetermined cause. The 3-year cumulative rates of CV death were similar between the invasive and conservative strategies (14.6% vs 12.6%, respectively; HR: 1.13, 95% CI: 0.75-1.70). Non-CV death rates were also similar between the invasive and conservative arms (8.4% and 8.2%, respectively; HR: 1.25; 95% CI: 0.75-2.09). Sudden cardiac death (46.8% of CV deaths) and infection (54.2% of non-CV deaths) were the most common cause-specific deaths and did not vary by treatment strategy.

CONCLUSIONS

In ISCHEMIA-CKD, CV death was more common than non-CV or undetermined death during the 3-year follow-up. The randomized treatment assignment did not affect the cause-specific incidences of death in participants with advanced CKD and moderate or severe myocardial ischemia. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches-Chronic Kidney Disease [ISCHEMIA-CKD]; NCT01985360).

Cardio-selective versus non-selective β-blockers for cardiovascular events and mortality in long-term dialysis patients: A systematic review and meta-analysis

BACKGROUND

Trials in patients receiving dialysis have demonstrated that β-blockers reduce all-cause mortality and cardiovascular events. However, differences still exist within-class comparative effectiveness studies of the therapeutic benefits of β-blockers in dialysis patients.

OBJECTIVE

The purpose of this systematic review is to examine whether cardiovascular events and all-cause mortality differed between dialysis patients receiving cardio-selective and non-selective agents.

METHODS

A comprehensive search of relevant articles from the PubMed, EMBASE, Cochrane Central Register and ClinicalTrials.gov was performed up to September 4, 2022, we included adults receiving β-blockers to evaluate the effects of cardio-selective versus non-selective agents on mortality and cardiovascular events in the dialysis population. Hazard ratios (HRs) and 95% confidence intervals (CIs) were examined for the negative outcomes of cardiovascular events and death for any reason. The risk of bias in randomized controlled trials (RCTs) was assessed using Cochrane's risk of bias tool and the risk of bias in observational studies was assessed using a table designed according to the ROBINS-I tool, the evidence grade was assessed using the GRADE guideline. For all-cause mortality and cardiovascular events, the RevMan software (version 5.3) was used to calculate pooled HRs with 95% CI. The heterogeneity (I2) in statistics was used to examine the degree of heterogeneity among studies.

RESULTS

Four observational studies, including 58, 652 long-term dialysis patients, were included in the meta-analysis. Compared to dialysis patients who took non-selective β-blockers, who took cardio-selective β-blockers was probably associated with fewer cardiovascular events (hazard ratio [HR] = 0.85, 95% confidence interval [CI] = 0.81, 0.89, heterogeneity [I2] = 0%, three trials, 52,077 participants, moderate-quality evidence) and may have lower all-cause mortality (HR = 0.83, 95% CI = 0.69, 0.99, I2 = 91%, four trials, 54,115 participants, low-quality evidence).

CONCLUSIONS

This systematic review showed that cardio-selective β-blockers are probably associated with fewer cardiovascular events and may have lower all-cause mortality in long-term dialysis patients than non-selective β-blockers. The present study results need to be replicated using randomized controlled trials with longer observation durations.

Cerebrovascular Disease, Cardiovascular Disease, and Chronic Kidney Disease: Interplays and Influences

PURPOSE OF REVIEW

We reviewed reasons for the high cardiovascular risk (CVD) of patients with chronic kidney disease (CKD), and explored alternatives to treatment of traditional risk factors to reduce CVD in CKD.

RECENT FINDINGS

Besides traditional risk factors, patients with CKD are exposed to uremic toxins of two kinds: systemically derived toxins include asymmetric dimethylarginine (ADMA), total homocysteine (tHcy), thiocyanate, tumor necrosis factor alpha, and interleukin 6. Gut-derived uremic toxins (GDUT), products of the intestinal microbiome, include hippuric acid, indoxyl sulfate, p-cresyl sulfate, p-cresyl glucuronide, phenylacetylglutamine, and trimethylamine N-oxide (TMAO). Cyanocobalamin is toxic in patients with CKD. Approaches to reducing plasma levels of these uremic toxins would include diet to reduce GDUT, kidney transplantation, more intensive dialysis, and vitamin therapy to lower tHcy with methylcobalamin rather than cyanocobalamin. The high CVD risk in CKD requires consideration of therapies beyond treatment of traditional risk factors.

Reduced Blood Pressure Dipping Is A Risk Factor for the Progression of Chronic Kidney Disease in Children

Background: Elevated blood pressure and proteinuria are well-established risk factors for chronic kidney disease (CKD) progression in children. This study aimed to analyze risk factors for CKD progress, emphasizing detailed ambulatory blood pressure (ABPM) data. Methods: In 55 children with CKD II−V, observed for ≥1 year or until initiation of kidney replacement therapy, we analyzed ABPM, clinical, and biochemical parameters. Results: At the beginning, the glomerular filtration rate (eGFR) was 66 (interquartile range—IQR: 42.8−75.3) mL/min/1.73 m2, and the observation period was 27 (16−36) months. The mean eGFR decline was 2.9 ± 5.7 mL/min/1.73 m2/year. eGFR decline correlated (p < 0.05) with age (r = 0.30), initial proteinuria (r = 0.31), nighttime systolic and mean blood pressure (r = 0.27, r = 0.29), and systolic and diastolic blood pressure dipping (r = −0.37, r = −0.29). There was no relation between mean arterial pressure during 24 h (MAP 24 h Z-score) and eGFR decline and no difference in eGFR decline between those with MAP 24 h < and ≥50 th percentile. In multivariate analysis, systolic blood pressure dipping (beta = −0.43), presence of proteinuria (beta = −0.35), and age (beta = 0.25) were predictors of eGFR decline. Conclusions: Systolic blood pressure dipping may be a valuable indicator of CKD progression in children.

Small renal masses in kidney transplantation: overview of clinical impact and management in donors and recipients

Kidney transplantation is the best replacement treatment for the end-stage renal disease. Currently, the imbalance between the number of patients on a transplant list and the number of organs available constitutes the crucial limitation of this approach. To expand the pool of organs amenable for transplantation, kidneys coming from older patients have been employed; however, the combination of these organs in conjunction with the chronic use of immunosuppressive therapy increases the risk of incidence of graft small renal tumors. This narrative review aims to provide the state of the art on the clinical impact and management of incidentally diagnosed small renal tumors in either donors or recipients. According to the most updated evidence, the use of grafts with a small renal mass, after bench table tumor excision, may be considered a safe option for high-risk patients in hemodialysis. On the other hand, an early small renal mass finding on periodic ultrasound-evaluation in the graft should allow to perform a conservative treatment in order to preserve renal function. Finally, in case of a renal tumor in native kidney, a radical nephrectomy is usually recommended.

Is Preemptive Kidney Transplantation Associated With Improved Outcomes when Compared to Non-preemptive Kidney Transplantation in Children? A Systematic Review and Meta-Analysis

Main Problem: Preemptive kidney transplantation (PKT) is performed prior to dialysis initiation to avoid dialysis-related morbidity and mortality in children and adolescents. We undertook a systematic review to compare clinical outcomes in PKT versus kidney transplantation after dialysis initiation in paediatric patients.

Methods: The bibliographic search identified studies that compared paediatric recipients of a first or subsequent, living or deceased donor PKT versus non-preemptive kidney transplant. Methodological quality was assessed for all studies. Data were pooled using the random-effects model.

Results: Twenty-two studies (n = 22,622) were included. PKT reduced the risk of overall graft loss (relative risk (RR) .57, 95% CI: .49–.66) and acute rejection (RR: .81, 95% CI: .75–.88) compared to transplantation after dialysis. Although no significant difference was observed in overall patient mortality, the risk of patient death was found to be significantly lower in PKT patients with living donor transplants (RR: .53, 95% CI: .34–.83). No significant difference was observed in the incidence of delayed graft function.

Conclusion: Evidence from observational studies suggests that PKT is associated with a reduction in the risk of acute rejection and graft loss. Efforts should be made to promote and improve rates of PKT in this group of patients (PROSPERO).

Systematic Review Registration:https://clinicaltrials.gov/, CRD42014010565

Renal Cell Carcinoma and Kidney Transplantation: A Narrative Review

Kidney transplant recipients (KTRs) are at increased risk of developing renal cell carcinoma (RCC). The cancer can be encountered at different steps in the transplant process. RCC found during work-up of a transplant candidate needs treatment and to limit the risk of recurrence usually a mandatory observation period before transplantation is recommended. An observation period may be omitted for candidates with incidentally discovered and excised small RCCs (<3 cm). Likewise, RCC in the donor organ may not always preclude usage if tumor is small (<2 to 4 cm) and removed with clear margins before transplantation. After transplantation, 90% of RCCs are detected in the native kidneys, particularly if acquired cystic kidney disease has developed during prolonged dialysis. Screening for RCC after transplantation has not been found cost-effective. Treatment of RCC in KTRs poses challenges with adjustments of immunosuppression and oncologic treatments. For localized RCC, excision or nephrectomy is often curative. For metastatic RCC, recent landmark trials in the nontransplanted population demonstrate that immunotherapy combinations improve survival. Dedicated trials in KTRs are lacking. Case series on immune checkpoint inhibitors in solid organ recipients with a range of cancer types indicate partial or complete tumor response in approximately one-third of the patients at the cost of rejection developing in ~40%.

Cardiovascular disease in children with chronic kidney disease

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is a significant cause of morbidity and mortality in children with chronic kidney disease (CKD). The cause of CVD in children with CKD is multifactorial and there are new and emerging data regarding prevalence and risk factors for CVD in this population.

RECENT FINDINGS

A number of recent publications from longitudinal cohort studies of children with CKD have greatly increased our knowledge about the prevalence and risk factors for CVD including hypertension, obesity and dyslipidaemia. Masked hypertension and isolated nocturnal hypertension both correlate with surrogate markers of CVD in children. Obesity and adiposity are associated with an increased risk of CVD. Markers other than BMI such as waist to height ratio and fat-free tissue to fat tissue ratio better correlate with the presence of CVD in children. Dyslipidaemia is extremely prevalent in the paediatric CKD population, but there is a lack of consensus on treatment. More data on the relationship between bone mineral disease and CVD continue to emerge including an association between hyperparathyroidism and isolated nocturnal hypertension.

SUMMARY

Children with CKD have multiple potentially modifiable risk factors for CVD. Research focused on CVD outcomes in children is needed.