Change in cardiac geometry and function in CKD children during strict BP control: a randomized study

Changes in the cardiovascular risk profile in children approaching kidney replacement therapy

Background

Despite significant cardiovascular (CV) morbidity in children on dialysis and after kidney transplantation, data on the evolution of CV damage in children with chronic kidney disease (CKD) approaching kidney replacement therapy (KRT) is unknown.

Methods

The burden, progression, and predictors of CV damage before KRT onset were explored in two prospective multicenter cohorts from Europe and Canada: Cardiovascular Comorbidity in Children with CKD (4C) and Haemodiafiltration, Heart and Height (3H) studies, conducted from 2009-19 and 2013-16, respectively. CV damage and risk factors were evaluated (i) cross sectionally at KRT-start (n = 248), and (ii) longitudinally over the 2-years preceding KRT start (n = 157; 331 patient-visits). Longitudinal analyses with mixed-effects models estimated associations of modifiable CV risk factors with change in carotid intima-media thickness (cIMT) standard deviation score (SDS), pulse wave velocity (PWV-SDS), left ventricular (LV) mass and systolic dysfunction.

Findings

248 patients, age 14.3 (12.2, 16.2) years were evaluated at median 35 (28-114) days before KRT start. Elevated cIMT-SDS and PWV-SDS were present in 43% and 25%, and LV hypertrophy and systolic dysfunction in 49% and 33%. Aortic stiffness and LV hypertrophy significantly increased, especially in the year before KRT start (adjusted odds ratio, OR 0.33, P = 0.002 and OR 0.54, P = 0.01, respectively). 79% of children had >3 modifiable CV risk factors at KRT onset. Diastolic BP and BMI were strongly associated with a linear increase in all CV measures. After controlling for CV risk factors, the time to KRT onset no longer predicted the burden of CV damage.

Interpretation

This comprehensive CV evaluation shows the progressive accrual of modifiable risk factors and a high burden of CV damage in the years preceding KRT onset. CV damage in the pre-KRT period is preventable.

Funding

Supported by EU4Health Programme (101085068) and Kidney Research UK (RP39/2013).

Long-Term Cardiovascular Outcomes in Children and Adolescents With Hypertension

Importance

Hypertension affects 6% of all children, and its prevalence is increasing. Childhood hypertension tracks into adulthood and is associated with subclinical cardiovascular disease; however, there is a lack of evidence linking childhood hypertension to cardiovascular outcomes, which may contribute to underdiagnosis and undertreatment.

Objective

To determine the long-term associated risk of major adverse cardiac events (MACE) among children diagnosed with hypertension.

Design, Setting, and Participants

This was a population-based, retrospective, matched cohort study conducted from 1996 to 2022. The study included all children (aged 3-18 years) alive in Ontario, Canada, from 1996 to 2021, who were identified using provincial administrative health databases. Children with prior kidney replacement therapy were excluded.

Exposure

Incident hypertension diagnosis, identified by validated case definitions using diagnostic and physician billing claims. Each case was matched with 5 controls without hypertension by age, sex, birth weight, maternal gestational hypertension, prior comorbidities (chronic kidney disease, diabetes, cardiovascular surgery), and a propensity score for hypertension.

Main Outcomes and Measures

The primary outcome was MACE (a composite of cardiovascular death, stroke, hospitalization for myocardial infarction or unstable angina, or coronary intervention). Time to MACE was evaluated using the Kaplan-Meier method and Cox proportional hazards regression.

Results

A total of 25 605 children (median [IQR] age, 15 [11-17] years; 14 743 male [57.6%]) with hypertension were matched to 128 025 controls without hypertension. Baseline covariates were balanced after propensity score matching, and prior comorbidities were uncommon (hypertension vs control cohort: malignancy, 1451 [5.7%] vs 7908 [6.2%]; congenital heart disease, 1089 [4.3%] vs 5408 [4.2%]; diabetes, 482 [1.9%] vs 2410 [1.9%]). During a median (IQR) of 13.6 (7.8-19.5) years of follow-up, incidence of MACE was 4.6 per 1000 person-years in children with hypertension vs 2.2 per 1000 person-years in controls (hazard ratio, 2.1; 95% CI, 1.9-2.2). Children with hypertension were at higher associated risk of stroke, hospitalization for myocardial infarction or unstable angina, coronary intervention, and congestive heart failure, but not cardiovascular death, compared with nonhypertensive controls.

Conclusions and Relevance

Children diagnosed with hypertension had a higher associated long-term risk of MACE compared with controls without hypertension. Improved detection, follow-up, and control of pediatric hypertension may reduce the risk of adult cardiovascular disease.

Stricter Blood Pressure Control Is Associated With Lower Left Ventricular Mass in Children After Kidney Transplantation: A Longitudinal Analysis of the 4C-T Study

BACKGROUND

We assessed the effect of blood pressure (BP) control on left ventricular mass index (LVMI) and left ventricular hypertrophy (LVH).

METHODS

Ninety-six patients (64 males) ≥9 months post-kidney transplantation from the 4C-T (Cardiovascular Comorbidity in Children with Chronic Kidney Disease and Transplantation) study were analyzed longitudinally (mean follow-up, 2.6±1.3 years). Cumulative systolic blood pressure (SBP)/diastolic BP exposure was calculated as a time-averaged area under the curve and categorized: ≤50th, 50th to ≤75th, 75th to ≤90th, and >90th percentile (pct). We performed adjusted linear and logistic mixed models for LVMI and LVH, respectively.

RESULTS

At baseline, LVMI was 49.7±12.7g/m2.16 with 64% (n=61) kidney transplantation recipients displaying LVH. Compared with patients with cumulative SBP exposure >90th pct, patients with cumulative SBP of 50th to ≤75th showed a significant LVMI reduction of -5.24g/m2.16 (P=0.007). A similar tendency was seen for cumulative SBP≤50th (β=-3.70 g/m2.16; P=0.067), but patients with cumulative SBP of 75th to ≤90th pct showed no reduction. A post hoc analysis in patients with cumulative SBP≤75th revealed that median SBP exposure was at 57.5th pct. For cumulative diastolic BP, a significant LVMI reduction was seen in all 3 categories ≤90th pct compared with patients >90th pct. Patients with cumulative SBP of ≤50th or 50th to ≤75th pct showed 79% or 83% lower odds of developing LVH, respectively. Patients with cumulative diastolic BP ≤50th showed a tendency of 82% lower odds for LVH (95% CI, 0.03-1.07).

CONCLUSIONS

Stricter BP control led to regression of LVMI and LVH. Our data suggest a BP target below the 60th pct, which needs to be substantiated in a randomized controlled trial.

Ambulatory Blood Pressure Monitoring in Pediatrics, an Update on Interpretation and Classification of Hypertension Phenotypes

PURPOSE OF REVIEW

This review highlights the major changes reflected in the 2022 American Heart Association (AHA) Scientific Statement on Ambulatory Blood Pressure Monitoring (ABPM) in Children and Adolescents with a specific focus on the newly defined phenotypes of hypertension and their epidemiology and associated outcomes.

RECENT FINDINGS

The 2022 AHA guidelines' most notable changes include the following: (1) alignment of blood pressure (BP) thresholds with the 2017 American Academy of Pediatrics (AAP) clinical practice guidelines, 2017 American College of Cardiology (ACC)/AHA hypertension guidelines, and 2016 European Society of Hypertension (ESH) pediatric recommendations; (2) expansion of the use of ABPM to diagnose and phenotype pediatric hypertension in all pediatric patients; (3) removal of BP loads from diagnostic criteria; and (4) simplified classification of new hypertension phenotypes to prognosticate risks and guide clinical management. Recent studies suggest that utilizing the 2022 AHA pediatric ABPM guidelines will increase the prevalence of pediatric ambulatory hypertension, especially for wake ambulatory hypertension in older, taller males and for nocturnal hypertension in both males and females ≥ 8 years of age. The new definitions simplify the ambulatory hypertension criteria to include only the elements most predictive of future health outcomes, increase the sensitivity of BP thresholds in alignment with recent data and other guidelines, and thus make hypertension diagnoses more clinically meaningful. This guideline will also aid in the transition of adolescents and young adults to adult medical care. Further studies will be necessary to study ambulatory BP norms in a more diverse pediatric population and evaluate the impact of these guidelines on prevalence and future outcomes.

Intensive compared with less intensive blood pressure control to prevent adverse cardiac remodelling in children with chronic kidney disease (HOT-KID): a parallel-group, open-label, multicentre, randomised, controlled trial

BACKGROUND

Optimal target blood pressure to reduce adverse cardiac remodelling in children with chronic kidney disease is uncertain. We hypothesised that lower blood pressure would reduce adverse cardiac remodelling.

METHODS

HOT-KID, a parallel-group, open-label, multicentre, randomised, controlled trial, was done in 14 clinical centres across England and Scotland. We included children aged 2-15 years with stage 1-4 chronic kidney disease-ie, an estimated glomerular filtration rate (eGFR) higher than 15 mL/min per 1·73 m2-and who could be followed up for 2 years. Children on antihypertensive medication were eligible as long as it could be changed to angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) if they were not already receiving these therapies. Participants were randomly assigned (1:1) to standard treatment (auscultatory office systolic blood pressure target between the 50th and 75th percentiles) or intensive treatment (systolic target <40th percentile) by the chief investigator using a rapid, secure, web-based randomisation system. ACE inhibitors or ARBs were used as first-line agents, with the dose titrated every 2-4 weeks to achieve the target blood pressure levels. The primary outcome was mean annual difference in left ventricular mass index (LVMI) by echocardiography measured by a masked observer and was assessed in the intention-to-treat population, defined as all the children who underwent randomisation irrespective of the blood pressure reached. Secondary and safety outcomes were the differences between groups in mean left ventricular relative wall thickness, renal function, and adverse effects and were also assessed in the intention-to-treat population. This trial is registered with ISRCTN, ISRCTN25006406.

FINDINGS

Between Oct 30, 2012, and Jan 5, 2017, 64 participants were randomly assigned to the intensive treatment group and 60 to the standard treatment group (median age of participants was 10·0 years [IQR 6·8-12·6], 69 [56%] were male and 107 [86%] were of white ethnicity). Median follow-up was 38·7 months (IQR 28·1-52·2). Blood pressure was lower in the intensive treatment group compared with standard treatment group (mean systolic pressure lower by 4 mm Hg, p=0·0012) but in both groups was close to the 50th percentile. The mean annual reduction in LVMI was similar for intensive and standard treatments (-1·9 g/m2·7 [95% CI -2·4 to -1·3] vs -1·2 g/m2·7 [-1·5 to 0·8], with a treatment effect of -0·7 g/m2·7 [95% CI -1·9 to 2·6] per year; p=0·76) and mean value in both groups at the end of follow-up within the normal range. At baseline, elevated relative wall thickness was more marked than increased LVMI and a reduction in relative wall thickness was greater for the intensive treatment group than for the standard treatment group (-0·010 [95% CI 0·015 to -0·006] vs -0·004 [-0·008 to 0·001], treatment effect -0·020 [95% CI -0·039 to -0·009] per year, p=0·0019). Six (5%) participants reached end-stage kidney disease (ie, an eGFR of <15 mL/min per 1·73 m2; three in each group) during the course of the study. The risk difference between treatment groups was 0·02 (95% CI -0·15 to 0·19, p=0·82) for overall adverse events and 0·07 (-0·05 to 0·19, p=0·25) for serious adverse events. Intensive treatment was not associated with worse renal outcomes or greater adverse effects than standard treatment.

INTERPRETATION

These results suggest that cardiac remodelling in children with chronic kidney disease is related to blood pressure control and that a target office systolic blood pressure at the 50th percentile is close to the optimal target for preventing increased left ventricular mass.

FUNDING

British Heart Foundation.

Cardiovascular Risks of Hypertension: Lessons from Children with Chronic Kidney Disease

Hypertension is the most common complication of chronic kidney disease (CKD) in children, having a strong association with subsequential cardiovascular disease (CVD). In pediatric CKD, a considerable percentage of children with hypertension are undiagnosed or undertreated. Prior research has evaluated structural and functional markers of subclinical CVD and biomarkers in adults with CKD, while ideal biomarkers in pediatrics are still insufficiently studied. The ultimate goal of this review is to summarize what is currently known about state of hypertension, cardiovascular risk factors, and potential CVD markers/biomarkers in children with pre-dialysis CKD. We discuss omics-related biomarkers and the pathophysiologic processes of endothelial dysfunction, kidney injury, oxidative stress and inflammation that are classified by specific biomarkers. Moreover, we illustrate the existing challenges and highlight the paucity of pediatric CKD research to evaluate these CVD biomarkers for future clinical pediatric practice. Thus, achieving clinical utility of CVD biomarkers for use in pediatric CKD remains a significant challenge requiring additional efforts.

Hypertension in Patients with Insulin Resistance: Etiopathogenesis and Management in Children

Insulin resistance (IR) is a key component in the etiopathogenesis of hypertension (HS) in patients with diabetes mellitus (DM). Several pathways have been found to be involved in this mechanism in recent literature. For the above-mentioned reasons, treatment of HS should be specifically addressed in patients affected by DM. Two relevant recently published guidelines have stressed this concept, giving specific advice in the treatment of HS in children belonging to this group: the European Society of HS guidelines for the management of high blood pressure in children and adolescents and the American Academy of Pediatrics Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents. Our aim is to summarize the main pathophysiological mechanisms through which IR causes HS and to highlight the specific principles of treatment of HS for children with DM.

High blood pressure in children and adolescents: current perspectives and strategies to improve future kidney and cardiovascular health

Hypertension is one of the most common causes of preventable death worldwide. The prevalence of pediatric hypertension has increased significantly in recent decades. The cause of this is likely multifactorial, related to increasing childhood obesity, high dietary sodium intake, sedentary lifestyles, perinatal factors, familial aggregation, socioeconomic factors, and ethnic blood pressure (BP) differences. Pediatric hypertension represents a major public health threat. Uncontrolled pediatric hypertension is associated with subclinical cardiovascular disease and adult-onset hypertension. In children with chronic kidney disease (CKD), hypertension is also a strong risk factor for progression to kidney failure. Despite these risks, current rates of pediatric BP screening, hypertension detection, treatment, and control remain suboptimal. Contributing to these shortcomings are the challenges of accurately measuring pediatric BP, limited access to validated pediatric equipment and hypertension specialists, complex interpretation of pediatric BP measurements, problematic normative BP data, and conflicting society guidelines for pediatric hypertension. To date, limited pediatric hypertension research has been conducted to help address these challenges. However, there are several promising signs in the field of pediatric hypertension. There is greater attention being drawn on the cardiovascular risks of pediatric hypertension, more emphasis on the need for childhood BP screening and management, new public health initiatives being implemented, and increasing research interest and funding. This article summarizes what is currently known about pediatric hypertension, the existing knowledge-practice gaps, and ongoing research aimed at improving future kidney and cardiovascular health.

Cardiac Abnormalities in Children with Pre-Dialysis Chronic Kidney Disease in a Resource-Limited Setting: A Cross-Sectional Observational Study

BACKGROUND

Cardiovascular disease is the leading cause of morbidity and mortality in children with chronic kidney disease (CKD). We aim to estimate the prevalence of cardiac abnormalities in children up to age 16 years with CKD and their association with various risk factors.

METHODS

This cross-sectional observational study was conducted on 107 CKD children. We assessed the systolic and diastolic function using 2D echocardiographic evaluation and M-mode measurements of the left ventricle (LV) indexed for BSA and z-scores were calculated. Results were compared with age, sex, stage of CKD, anaemia, estimated glomerular filtration rate (eGFR) and various laboratory parameters.

RESULTS

LV diastolic dysfunction was seen in 88%, followed by increased LV dimensions in 33.6%, LV systolic dysfunction in 16%, right ventricle systolic dysfunction in 11.2% while increased pulmonary artery (PA) systolic pressure was seen in 9.3% of cases. LV dimensions correlated directly with parathormone levels and inversely with eGFR, serum calcium and haemoglobin levels. Left ventricular hypertrophy correlated directly with parathormone while inversely with eGFR, serum calcium and haemoglobin. Ejection fraction directly correlated to eGFR and serum calcium while inversely related to parathormone. Left PA pressure directly correlated with age and inversely with eGFR. Right ventricular systolic function assessed by tricuspid annular plane systolic excursion correlated inversely with haemoglobin.

CONCLUSION

LV diastolic dysfunction and increased LV dimensions were the most common cardiac abnormality in children with CKD. LV dimensions correlated directly with parathormone levels and inversely with eGFR, serum calcium and haemoglobin. Diastolic dysfunction positively correlated with serum creatinine and parathormone levels.

L-type calcium channel blocker use and proteinuria among children with chronic kidney diseases

BACKGROUND

Hypertension is common among children with chronic kidney disease (CKD), and dihydropyridine calcium channel blockers (dhCCBs) are frequently used as treatment. The impact of dhCCBs on proteinuria in children with CKD is unclear.

METHODS

Data from 722 participants in the Chronic Kidney Disease in Children (CKiD) longitudinal cohort with a median age of 12 years were used to assess the association between dhCCBs and log transformed urine protein/creatinine levels as well as blood pressure control measured at annual visits. Angiotensin-converting enzyme inhibitor (ACEi) and angiotensin receptor blocker (ARB) use was evaluated as an effect measure modifier.

RESULTS

Individuals using dhCCBs had 18.8% higher urine protein/creatinine levels compared to those with no history of dhCCB or ACEi and ARB use. Among individuals using ACEi and ARB therapy concomitantly, dhCCB use was not associated with an increase in proteinuria. Those using dhCCBs had higher systolic and diastolic blood pressures.

CONCLUSIONS

Use of dhCCBs in children with CKD and hypertension is associated with higher levels of proteinuria and was not found to be associated with improved blood pressure control.

Challenges in choosing the appropriate guidelines for use in children and adolescents with hypertension

BACKGROUND

This study was designed to observe the effect of antihypertensive treatment on blood pressure (BP) and target organ damage in patients followed up according to the American Academy of Pediatrics Hypertension Guidelines (AAPG). The results were also assessed in comparison with the definitions and target organ damage according to the European Society of Hypertension Guidelines 2016 (ESHG).

MATERIALS AND METHODS

A total of 44 (34 male) out of 140 patients were enrolled in the study and the mean age was 14±3.19years. The follow-up period was at least 12months. All patients underwent the following assessments: anthropometrical measurements of body mass index (BMI), left ventricular mass index (LVMI), and biochemical parameters according to the relevant guidelines. The pre-treatment and post-treatment datasets collected were compared.

RESULTS

The frequency of symptomatic patients decreased from 88% to 30%. After treatment, 29.4% (n=13) of patients still had elevated and stage 1 hypertension (HT) according to the AAPG. These patients were older and had higher BMI z-scores, LVMI z-scores, mean BP indices, and also had longer symptom duration than normotensive patients (P<0.001). When patients were assessed according to the ESHG, 34.1% (n=15) of patients had high-normal stage 1 and stage 2 HT. While 53.3% (n=8) of the patients aged 13-15years were classified as having high-normal stage 1 and stage 2 HT according to the ESHG, 33.3% (n=5) were classified as having elevated BP and stage 1 HT according to the AAPG. Additionally, 36.4% (n=4) of the patients aged≥16years were classified as having high-normal and stage 1 HT according to the ESHG, whereas 45.5% (n=5) were classified as having elevated BP and stage 1 HT according to the AAPG.

CONCLUSION

To control HT in children with higher BMI z-scores, higher LVMI z-scores, and higher BP indices, an earlier and more intensive approach is needed. Considering that the duration of exposure to HT may also affect the LVMI, adjusting age and gender or decreasing the current thresholds for LVMI may lead to an earlier diagnosis for more patients. According to the present classifications, the ESHG covers more children aged between 13 and 15years in contrast to the AAPG, which covers more patients aged≥16years. However, further studies are needed to confirm these results.

Left-ventricular diastolic dysfunction in Korean children with chronic kidney disease: data from the KNOW-Ped CKD study

Background

Cardiovascular disease (CVD) is the most common cause of mortality in pediatric chronic kidney disease (CKD) patients. Left ventricular (LV) hypertrophy (LVH) is associated with LV diastolic dysfunction (LVDD) development and is used as an early marker of CVD in pediatric CKD. This study aimed to assess the prevalence and risk factors of LVDD and the association between LVH and LVDD in Korean pediatric CKD patients.

Methods

Data were collected using the baseline data of the Korean cohort study for outcome in patients with pediatric chronic kidney disease, a nationwide, 10-year, prospective, observational cohort study of pediatric CKD. A total of 244 patients were included in the final analysis. Two-dimensional echocardiography and tissue Doppler images were used to evaluate LVH and LVDD. LVH was defined as an LV mass index (LVMI) ≥38 g/m^2.7 and LV-wall thickness z-score > 1.64. LVDD was defined as a mitral peak velocity of early filling to early diastolic mitral annular velocity (E/E’) > 14. Univariate and multivariate logistic regression analyses were performed to evaluate risk factors of LVDD.

Results

In this study, the male-to-female ratio was 2.2 (168:76) and median age was 11.2 years. The average estimated glomerular filtration rate was 57.4 ml/min/1.73 m², and no patients received renal replacement therapy. The mean value of LVMI and E/E’ was 37.0 g/m^2.7 and 7.4, respectively. The prevalence of LVH was 40.1 and 17.4% by LVMI ≥38 g/m^2.7 and LV-wall thickness z-score, respectively. The prevalence of LVDD was 4.5%, and patients with LVH showed greater risk of LVDD (odds ratio 7.3, p = 0.012). In the univariate analysis, young age, low hemoglobin level, higher LVMI, and higher LV-wall thickness z-score were associated with LVDD. In the multivariate analysis, young age, low hemoglobin level, and higher LV-wall thickness z-score were independently associated with LVDD.

Conclusion

This study shows that LVH patients have a greater risk of LVDD and that anemia is the only modifiable risk factor for LVDD in Korean pediatric CKD patients.

Preterm birth and neonatal acute kidney injury: implications on adolescent and adult outcomes

As a result of preterm birth, immature kidneys are exposed to interventions in the NICU that promote survival, but are nephrotoxic. Furthermore, the duration of renal development may be truncated in these vulnerable neonates. Immaturity and nephrotoxic exposures predispose preterm newborns to acute kidney injury (AKI), particularly in the low birth weight and extremely preterm gestational age groups. Several studies have associated preterm birth as a risk factor for future chronic kidney disease (CKD). However, only a few publications have investigated the impact of neonatal AKI on CKD development. Here, we will review the evidence linking preterm birth and AKI in the NICU to CKD and highlight the knowledge gaps and opportunities for future research. For neonatal intensive care studies, we propose the inclusion of AKI as an important short-term morbidity outcome and CKD findings such as a reduced glomerular filtration rate in the assessment of long-term outcomes.

Evidence Gaps in the Identification and Treatment of Hypertension in Children

The ultimate goal of recognizing and treating hypertension in childhood is to prevent target-organ damage during childhood and to reduce the risk of adulthood cardiovascular disease. The quality of evidence to guide blood pressure management in children is lower than in adult medicine, yet some common findings support clinical practice recommendations. Oscillometric devices are increasingly replacing manual blood pressure measurements, but evidence shows that readings are not equivalent between the 2 methods. In addition, multiple blood pressure readings are needed before diagnosing a child with hypertension, but the optimal number and timing are still being determined. The recent American Academy of Pediatrics blood pressure guideline has revised the normative data tables and included threshold blood pressure limits which seem to identify children with higher cardiovascular risks. Threshold limits vary between guidelines, and the most accurate threshold has yet to be determined. Lifestyle modifications are a cornerstone of hypertension management, but the optimal diet and physical activity changes for beneficial effect are not known. When pharmacotherapy is needed, physicians have used drugs from all antihypertensive classes in children, yet only a few classes have been systematically studied. The long-term cardiovascular consequences of elevated blood pressure during childhood are under investigation and it seems that the lower the childhood blood pressure the better and that the rate of change during childhood is predictive of adulthood disease. With much still to learn, this article summarizes the evidence and the evidence gaps for the diagnosis, investigation, management, and outcomes of pediatric hypertension.

Subclinical Organ Damage in Children and Adolescents with Hypertension: Current Guidelines and Beyond

High blood pressure (BP) is becoming a growing health issue even in children and adolescents. Moreover, BP elevation in youth frequently translates into children and adult hypertension contributing to the development of cardiovascular disease. The detection of early markers of vascular damage, potentially leading to overt cardiovascular disease, is important for clinical decisions about if and how to treat hypertension and can be useful in monitoring the effectiveness of the treatment. The purpose of this review is to summarize the actual knowledge about subclinical organ damage (SOD) in hypertensive children and adolescents and its association with cardiovascular disease in children and young adults. Our focus is especially put on left ventricular mass, pulse wave velocity, carotid intima-media thickness and microalbuminuria. We also want to address the scientific evidence about possible regression of SOD and cardiovascular risk with the use of behavioural and specific anti-hypertensive therapy. Indications from current guidelines are critically discussed.

Improved blood pressure and left ventricular remodelling in children on chronic intermittent haemodialysis: a longitudinal study

OBJECTIVES

We aimed to examine longitudinal changes in left ventricular (LV) structure and function and evaluate factors associated with LV remodelling in children on chronic haemodialysis.

METHODS

Retrospective longitudinal study including all children from the start of chronic haemodialysis with two or more m-mode 2D echocardiograms and tissue Doppler studies. Left ventricular mass (LVM) in g/m^2.7, geometry and LV function were compared at baseline (dialysis start) with follow-up studies at least 6 months following commencement. Left ventricular hypertrophy (LVH) was defined if greater than 95th percentile as per age-specific centiles. We also defined LVH as indexed LV mass index (LVMI) > 51 g/m^2.7 and using LV mass-for-height z-scores greater than the 95th percentile. Biochemical data, interdialytic weight change and blood pressure level were assessed for their association with change in indexed LVM.

RESULTS

Twenty-three of the 32 children < 18 years were included (n = 5, < 5 years) with last follow-up study performed following dialysis after a median (IQR) of 21 (10-34) months. The prevalence of LVH reduced significantly (69.6%, (n = 16/23) vs. 39.1% (n = 9/23), P = 0.002); LV geometry improved (13% concentric and 56.5% eccentric vs. 8.7% and 17.4% respectively) with mean ± SD reduction in indexed LVM (50.8 ± 23.1 g/m^2.7 vs. 38.6 ± 14.7 g/m^2.7, P = 0.002) and LV mass-for-height z-scores (0.67 ± 1.66 vs. - 0.46 ± 1.88, P = 0.002) from baseline to last follow-up respectively. There was no change in systolic function (LV fractional shortening, 37% vs. 38%, P = 0.39) and diastolic function (mean E/E' 10.8 vs. 9.0, P = 0.09). Multiple regression analysis identified improved systolic BP control (β = 0.41, P = 0.04) as an independent predictor for change in indexed LVM.

CONCLUSIONS

LV structure and function can improve in children despite long-term chronic intermittent haemodialysis. Cardiovascular health in this population does not always deteriorate but can be stabilised and indeed improved with optimal blood pressure management.

Impaired Systolic and Diastolic Left Ventricular Function in Children with Chronic Kidney Disease - Results from the 4C Study

Children with chronic kidney disease suffer from excessive cardiovascular mortality and early alterations of the cardiovascular system. Tissue doppler imaging is a validated echocardiographic tool to assess early systolic and diastolic cardiac dysfunction. We hypothesized that tissue Doppler velocities would reveal reduced cardiac function in children with chronic kidney disease compared to healthy children. A standardized echocardiographic exam was performed in 128 patients of the Cardiovascular Comorbidity in Children with Chronic Kidney Disease (4C) Study aged 6–17 years with an estimated glomerular filtration rate (eGFR) below 60 ml/min/1.73 m². Tissue Doppler measurements included early (E’) and late (A’) diastolic and systolic (S’) velocity at the mitral and septal annulus of the left ventricle. Measured values were normalized to z-scores using published reference data. Predictors of E’/A’, E/E’, S’ and left ventricular mass index (LVMI) were assessed by multiple linear regression analyses. Tissue Doppler E’ was reduced and tissue Doppler A’ increased, resulting in a reduced tissue Doppler E’/A’ ratio (z-score −0.14, p < 0.0001) indicating reduced diastolic function compared to healthy children. Reduced tissue Doppler E’/A’ Z-Scores were independently associated with lower eGFR (p = 0.002) and increased systolic blood pressure (p = 0.02). While E/E’ Z-Scores were increased (Z-score 0.57, p < 0.0001), patients treated with pharmacological RAS blockade but not with other antihypertensive treatments had significantly lower E/E’ and higher E’/A’ Z-Scores. Systolic tissue Doppler velocities were significantly decreased (Z-score −0.24, p = 0.001) and inversely correlated with E/E’ Z-Scores (r = −0.41, p < 0.0001). LVMI was not associated with systolic or diastolic tissue Doppler velocities. Concentric left ventricular hypertrophy showed a tendency to lower S’ in multivariate analysis (p = 0.13) but no association to diastolic function. Concentric left ventricular geometry was significantly associated with lower midwall fractional shortening. In summary, systolic and diastolic function assessed by tissue Doppler is impaired. eGFR, systolic blood pressure and the type of antihypertensive medications are significant predictors of diastolic function in children with CKD. Left ventricular morphology is largely independent of tissue Doppler velocities. Tissue Doppler velocities provide sensitive information about early left ventricular dysfunction in this population.

Cardiovascular disease risk among children with focal segmental glomerulosclerosis: a report from the chronic kidney disease in children study

BACKGROUND

The aims were to compare the cardiovascular disease (CVD) risk among children with chronic kidney disease (CKD) secondary to focal segmental glomerulosclerosis (FSGS) with the CVD risk of children with CKD due to other diagnoses.

METHODS

Casual blood pressure (BP), ambulatory blood pressure monitoring (APBM), echocardiogram, lipids, carotid intima medial thickness (cIMT), and uric acid obtained from participants in the Chronic Kidney Disease in Children (CKiD) cohort were analyzed longitudinally. Seventy-nine children with FSGS (FSGS-CKD) were compared to 196 children with non-FSGS glomerular disease (GDO-CKD) and 616 children with non-glomerular disease (NG-CKD).

RESULTS

At baseline, FSGS-CKD (median 14 years) had ambulatory hypertension (24.6%), masked hypertension (46.2%), left ventricular hypertrophy (LVH) (26.3%), and dyslipidemia (60.0%). In adjusted models, FSGS-CKD had higher systolic BP z-score (0.52 vs 0.11 and 0.23, p = 0.002 and 0.02), triglycerides (133 vs 109 and 102 mg/dl, p = 0.007 and < 0.001), and non-high density lipoprotein (144 vs 132 and 119 mg/dl, p = 0.07 and < 0.001) at baseline when compared to GDO-CKD and NG-CKD, respectively. Left ventricular mass index (LVMI) (36.0 vs 31.7 g/m^2.7, p < 0.001) and the odds of LVH (OR 3.38, 95% CI 1.42, 8.08) at baseline were greater in FSGS-CKD compared to NG-CKD. Adjusted longitudinal analysis showed that FSGS-CKD had a faster decline in LVMI than NG-CKD, and FSGS-CKD had a faster increase in uric acid compared to both groups.

CONCLUSIONS

Children with CKD due to FSGS had a relatively high prevalence of CVD risk factors. FSGS was associated with greater CVD risk when compared to other CKD diagnoses.

Cardiovascular Disease in Children and Adolescents With Chronic Kidney Disease

The lifespan of children with advanced chronic kidney disease (CKD), although improved over the past 2 decades, remains low compared with the general pediatric population. Similar to adults with CKD, cardiovascular disease accounts for a majority of deaths in children with CKD because these patients have a high prevalence of traditional and uremia-related risk factors for cardiovascular disease. The cardiovascular alterations that cause these terminal events begin early in pediatric CKD. Initially, these act to maintain hemodynamic homeostasis. However, as the disease progresses, these modifications are unable to sustain cardiovascular function in the long term, leading to left ventricular failure, depressed cardiorespiratory fitness, and sudden death. In this review, we discuss the prevalence of the risk factors associated with cardiovascular disease in pediatric patients with CKD, the pathophysiology that stimulates these changes, the cardiac and vascular adaptations that occur in these patients, and management of the cardiovascular risk in these patients.

Kidney Transplant in Pediatric Patient With Heart Failure: Case Report

Chronic kidney disease is defined as irreversible and progressive damage of the kidney. Chronicity is defined by the presence of renal dysfunction for at least 3 months, and renal dysfunction is defined through combinations of investigation (abnormal radiologic findings, abnormal urine or abnormal biochemistry reflecting renal dysfunction) and/or documentation of glomerular filtration rate below 60 mL/min/1.73 m². The case patient was a girl of 11 years of age, with diagnosis of chronic renal disease, of unknown cause, under renal replacement therapy with peritoneal dialysis, with progressive deterioration of general status and decrease of functional capacity and tolerance to physical activity, presence of fatigue, pulmonary congestion, retention of liquids, and edema in lower extremities, even with adjustment of medical treatment. Transplant was performed from a related living donor, without incidents or complications. The results of pediatric kidney trans plant are excellent, offering a high quality of life for recipients; many patients return to school. It is consi dered the criterion standard for the treatment of pediatric endstage renal disease with excellent allograft function and subsequent resolution of systolic dysfunction.

Pathophysiology and treatment of cardiovascular disease in pediatric chronic kidney disease

Life expectancy in patients with all stages of chronic kidney disease (CKD) falls far short of that in the general population. Cardiovascular disease is the leading cause of mortality in pediatric patients with CKD. In contrast to the intimal atherosclerotic lesions that characterize cardiovascular disease in the general population, vascular endothelial dysfunction, medial arterial calcification, and cardiac dysfunction contribute to cardiovascular pathological conditions in CKD. The pathogenesis of these lesions, the origins of which can be identified in the absence of traditional cardiovascular risk factors, is incompletely understood. CKD-mediated vascular calcification in CKD is characterized by a transition of vascular smooth muscle cells to an osteoblast-like phenotype and altered bone and mineral metabolism are strongly linked to progressive cardiovascular disease in this population. Renal osteodystrophy therapies, including phosphate binders, vitamin D analogs, and calcimimetics, have an impact on the progression of cardiovascular disease. However, cardiovascular disease has its origins before the development of secondary hyperparathyroidism, and optimal therapeutic regimens that minimize cardiac dysfunction, vascular calcification, and early mortality remain to be defined.

Clinical value of ambulatory blood pressure in pediatric patients after renal transplantation

Hypertension is a highly prevalent co-morbidity in pediatric kidney transplant recipients. Undertreated hypertension is associated with cardiovascular complications and negatively impacts renal graft survival. Thus, the accurate measurement of blood pressure is of the utmost importance for the correct diagnosis and subsequent management of post-renal transplant hypertension. Data derived from the general population, and to a lesser extent from the pediatric population, indicates that ambulatory blood pressure monitoring (ABPM) is superior to blood pressure measurements taken in the clinical setting for the evaluation of true mean blood pressure, identification of patients requiring antihypertensive treatment, and in the prediction of cardiovascular outcome. This Educational Review will discuss the clinical value of ABPM in the identification of individual blood pressure phenotypes, i.e., normotension, new-onset hypertension, white-coat hypertension, masked hypertension, controlled blood pressure, and undertreated/uncontrolled hypertension in pediatric kidney transplant recipients. Finally, we examine the utility of performing repeated ABPM for treatment monitoring of post-renal transplant hypertension and on surrogate markers related to relevant clinical cardiovascular outcomes. Taken together, our review highlights the clinical value of the routine use of ABPM as a tool for identifying and monitoring hypertension in pediatric kidney transplant recipients.

Left ventricular mass of persistent masked hypertension in Hong Kong Chinese adolescents: a 4-year follow-up study

OBJECTIVE

In our previous study, the prevalence of childhood masked hypertension was 11%. This study aims to assess the left ventricular mass index of persistent masked hypertension and determine the factors of elevated left ventricular mass index in Hong Kong Chinese adolescents from a community cohort.

DESIGN

Community prospective cohort study, follow-up of a case-control study in community.

SUBJECTS

Patients with masked hypertension at baseline were invited to recheck ambulatory blood pressure for the persistence of masked hypertension.

RESULTS

A total of 144 out of 165 patients with masked hypertension in the 2011/2012 ambulatory blood pressure survey consented to participate in the study. In all, 48 patients were found to have persistent masked hypertension by ambulatory blood pressure rechecking and were matched with normotensive controls by sex, age, and body height. The left ventricular mass (117.3±39.9 g versus 87.0±28.2 g versus 102.0±28.2 g) and left ventricular mass index (30.1±8.4 g/m2.7 versus 23.9±6.3 g/m2.7 versus 25.1±5.7 g/m2.7) were significantly higher in the persistent masked hypertension group (p<0.0001) compared with the patients without persistent masked hypertension and controls. In multivariate linear regression analysis, left ventricular mass index was found to be higher in male gender (β=4.874, p<0.0001) and the patients with persistent masked hypertension (β=2.796, p=0.003). In addition, left ventricular mass index was positively associated with body mass index z-score (β=3.045, p<0.0001) and low-density lipoprotein cholesterol concentration (β=1.634, p=0.015).

CONCLUSIONS

Persistent masked hypertension in adolescents is associated with elevated left ventricular mass index.

Cardiac and Vascular Target Organ Damage in Pediatric Hypertension

Atherosclerosis begins in youth and is associated with the presence of numerous modifiable cardiovascular (CV) risk factors, including hypertension. Pediatric hypertension has increased in prevalence since the 1980s but has plateaued in recent years. Elevated blood pressure levels are associated with impairments to cardiac and vascular structure and both systolic and diastolic function. Blood pressure-related increases in left ventricular mass (LVM) and abnormalities in cardiac function are associated with hard CV events in adulthood. In addition to cardiac changes, key vascular changes occur in hypertensive youth and adults. These include thickening of the arteries, increased arterial stiffness, and decreased endothelial function. This review summarizes the epidemiologic burden of pediatric hypertension, its associations with target organ damage (TOD) of the cardiac and vascular systems, and the impact of these adverse CV changes on morbidity and mortality in adulthood.

Factors associated with reduction of left ventricular mass in children on peritoneal dialysis

AIM

This study aimed to investigate sensitive factors involved in left ventricular mass reduction in children with end-stage renal disease (ESRD) undergoing peritoneal dialysis.

METHODS

Thirty-five subjects on peritoneal dialysis were enrolled. Two successive echocardiographic and clinical data for each subject were obtained. Blood pressure and left ventricular mass index (LVMI) were indexed through a division with the normal 95^th percentile value. Differences in numeric data between two datasets were calculated.

RESULTS

The mean age was 12.9 ± 4.6 years. Predictors of left ventricular hypertrophy and its persistence were systolic blood pressure index (P = 0.019 and P = 0.046) and E' velocity (P = 0.035 and P = 0.031) in univariate analysis. However, differences in these predictors between the datasets were not related to the change in indexed LVMI. Reduction in indexed LVMI was correlated to a reduction of indexed left atrial volume (R = 0.638, P = 0.001), trans-mitral A velocity (R = 0.443, P = 0.011), and serum blood urea nitrogen level (R = 0.372, P = 0.028) and an elevation of haemoglobin level (R = -0.374, P = 0.027).

CONCLUSION

The extent of circulating volume expansion is potentially the main predictive factor for change of LVMI, because the volume dependent diastolic functional variables correlate to the change of LVMI. Further study with a large number of ESRD children including a group under fluid volume control is needed to investigate the role of volume expansion on the change of LVMI.

Role of hypertension in progression of chronic kidney disease in children

PURPOSE OF REVIEW

Hypertension is an independent risk factor for progression of chronic kidney disease (CKD) in children. Children with early CKD develop hypertension secondary to renal disease. This review aims to highlight recent advances that help us better understand the current role of hypertension in progression of CKD in children.

RECENT FINDINGS

There is increasing evidence that children with CKD who have hypertension develop early atherosclerosis and cardiac adaptive changes. Emerging data from pediatric research in CKD show that elevated blood pressure is associated with the presence of abnormal subclinical markers of cardiovascular disease including increased carotid intima-media thickness, pulse wave velocity and left ventricular mass index. There is also some evidence that these early cardiovascular changes are reversible. Twenty-four hour ambulatory blood pressure monitoring (ABPM) is recommended in children with CKD by the American Academy of Pediatrics to diagnose hypertension.

SUMMARY

Hypertension is associated with subclinical cardiovascular disease in children with CKD. Early diagnosis of hypertension by ABPM and identification of subclinical cardiovascular changes provide a window for intervention, which may reverse early cardiovascular disease, thereby delaying dialysis and improving cardiovascular morbidity and mortality.

Effect of renal function on antihypertensive drug safety and efficacy in children

BACKGROUND

Hypertension and chronic kidney disease (CKD) are common comorbidities. Guidelines recommend treating hypertension in children with CKD because it is a modifiable risk factor for subsequent cardiovascular disease. Children with CKD are frequently excluded from antihypertensive drug trials. Consequently, safety and efficacy data for antihypertensive drugs are lacking in children with CKD.

METHODS

We determined the incidence of adverse events in 10 pediatric antihypertensive trials to determine the effect of renal function on antihypertensive safety and efficacy in children. These trials were submitted to the US Food and Drug Administration from 1998 to 2005. We determined the number and type of adverse events reported during the trials and compared these numbers in participants with normal renal function and those with decreased function (defined as an estimated glomerular filtration rate [eGFR] <90 mL/min/1.73 m2 calculated using the original Schwartz equation).

RESULTS

Among the 1,703 children in the 10 studies, 315 had decreased renal function. We observed no difference between the two cohorts in the incidence of adverse events or adverse drug reactions related to study drug. Only 5 participants, all with decreased renal function, experienced a serious adverse event; none was recorded by investigators to be study drug-related. Among treated participants, children with decreased renal function who received a high dose of study drug had a significantly larger drop in diastolic blood pressure compared with children with normal renal function.

CONCLUSIONS

These data show that antihypertensive treatment in children with renal dysfunction can be safe and efficacious, and consideration should be given to their inclusion in selected drug development programs.

Cardiovascular risks in chronic kidney disease pediatric patients

One of the common factors for the premature death in children is advanced chronic kidney disease (CKD). Most often cardiovascular disease (CVD) is the reason for mortality. The cardiovascular (CV) morbidity starts early in the disease process and renal transplanted children (CKD-T) are also at risk. The present review is focused on the current views of the cardiovascular risks during CKD in pediatric patients. Variable data sources for the latest literature collection were explored which mainly included PubMed and Google Scholar. The most important risk factors for subclinical CVD were a young age, elevated BMI and systolic blood pressure z-scores as well as a low GFR and present albuminuria. Increasing blood pressure and BMI over follow-up were also important cardiac risk factors longitudinally. The present review concludes that altered cardiac function and remodeling are a concurrent part of the CKD process, start early in the disease development, and persist after renal transplantation. The findings suggest that children with CKD or CKD-T are at high risk for future CVD where younger patients with elevated BMI and slightly increased blood pressures, as well as present albuminuria, are those at greatest risk, thus indicating targets for future interventions.

2016 European Society of Hypertension guidelines for the management of high blood pressure in children and adolescents

Increasing prevalence of hypertension (HTN) in children and adolescents has become a significant public health issue driving a considerable amount of research. Aspects discussed in this document include advances in the definition of HTN in 16 year or older, clinical significance of isolated systolic HTN in youth, the importance of out of office and central blood pressure measurement, new risk factors for HTN, methods to assess vascular phenotypes, clustering of cardiovascular risk factors and treatment strategies among others. The recommendations of the present document synthesize a considerable amount of scientific data and clinical experience and represent the best clinical wisdom upon which physicians, nurses and families should base their decisions. In addition, as they call attention to the burden of HTN in children and adolescents, and its contribution to the current epidemic of cardiovascular disease, these guidelines should encourage public policy makers to develop a global effort to improve identification and treatment of high blood pressure among children and adolescents.

Longitudinal assessment of myocardial function in childhood chronic kidney disease, during dialysis, and following kidney transplantation

BACKGROUND

Childhood chronic kidney disease (CKD) and dialysis are associated with increased long-term cardiovascular risk. We examined subclinical alterations in myocardial mechanics longitudinally in children with CKD, during dialysis, and following renal transplantation.

METHODS

Forty-eight children with CKD (stage III or higher) who received kidney transplants from 2008 to 2014 were included in a retrospective study and compared to 192 age- and sex-matched healthy children. Measurements of cardiac systolic and diastolic function were performed, and global longitudinal strain (GLS) and circumferential strain (GCS) were measured by speckle-tracking echocardiography at CKD, during dialysis, and 1 year following kidney transplantation. Mixed-effects modeling examined changes in GLS and GCS over different disease stages.

RESULTS

Children with CKD had a mean age of 10 ± 5 years and 67% were male. Eighteen children received preemptive transplantation. Children with CKD had increased left ventricular mass, lower GLS, and impaired diastolic function (lower E/A ratio and E' velocities) than healthy children. Changes in left ventricular diastolic parameters persisted during dialysis and after renal transplantation. Dialysis was associated with reduced GLS compared to CKD (β = 1.6, 95% confidence interval 0.2-3.0); however, this was not significant after adjustment for systolic blood pressure and CKD duration. Post-transplantation GLS levels were similar to those at CKD assessment. GCS was unchanged during dialysis but significantly improved following transplantation.

CONCLUSIONS

There are differences in diastolic parameters in childhood CKD that persist during dialysis and after transplantation. Systolic parameters are preserved, with significant improvement in systolic myocardial deformation following transplantation. The impact of persistent diastolic changes on long-term outcomes requires further investigation.

Influence of the Method of Definition on the Prevalence of Left-Ventricular Hypertrophy in Children with Chronic Kidney Disease: Data from the Know-Ped CKD Study

BACKGROUND/AIMS

Children with chronic kidney disease (CKD) have a high risk of cardiovascular disease. Left-ventricular (LV) hypertrophy (LVH) is an early marker of cardiovascular disease in pediatric CKD, and the prevalence of LVH in pediatric CKD is approximately 20-30% in pre-dialysis CKD patients. However, there is no consensus on the ideal method of defining LVH in pediatric CKD patients. Previous studies have typically used the LV mass index (LVMI), which is calculated as LV mass in grams divided by height in meters to the 2.7th power ≥ 38 g/m2.7, to diagnose LVH in children with CKD. Recently, age-specific reference values for LVMI ≥ 95th percentile and LV wall-thickness z-score > 1.64 in children were addressed. The aim of this study was to assess the prevalence and contributing factors of LVH in pediatric CKD patients according to each measurement and evaluate the concordance between each measurement.

METHODS

We used the baseline data of the KoreaN cohort study for Outcome in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD), which is a nationwide, 10-year, prospective, observational cohort study of pediatric CKD. A total of 469 patients were enrolled, and 458 patients were included in the final analysis. Univariate and multiple logistic regression analysis were performed to evaluate the association of the variables with LVH. Kappa statistics were used to analyze the concordance.

RESULTS

According to an LVH diagnosis of LVMI ≥ 38 g/m2.7, 188 patients (41.0%) were diagnosed with LVH, and the prevalence of LVH was high in younger patients (< 2 years of age). Using the age-specific reference values, 116 patients (25.3%) were diagnosed with LVH, and there was no difference in the prevalence of LVH according to age. Thirty-one patients (6.8%) were diagnosed with LVH using an LV wall-thickness z-score > 1.64. There is poor concordance between the diagnosis of LVH using the LV wall-thickness z-score and the LVMI method.

CONCLUSIONS

The results of this study show that there is poor concordance between the diagnosis of LVH using the wall-thickness z-score and the LVMI2.7 criteria. Further investigation is needed to estimate the correlation between LVH and cardiac dysfunction and to find a better method for defining LVH in the pediatric CKD cohort and thereby predicting cardiac dysfunction.

Oral paricalcitol: expanding therapeutic options for pediatric chronic kidney disease patients

The complex pathophysiology of progressive chronic kidney disease (CKD) and the development of mineral and bone disorder, abbreviated as CKD-MBD, is of vital importance to a pediatric patient. Paricalcitol, the 19 nor-1,25(OH)₂D₂ analogue was shown to be effective and safe in the treatment of secondary hyperparathyroidism (SHPT) in adults almost two decades ago. It also significantly improved survival in dialysis patients compared to the standard calcitriol. The successful treatment of CKD-MBD in children is essential if they are to grow and survive into adulthood. It can be argued that it is more important for children with CKD than adults since they have early and prolonged disease risk exposure. In this issue of Pediatric Nephrology, Webb et.al. report a dual trial of the safety, efficacy, and pharmacokinetics of paricalcitol in children aged 10-16 years with moderate but significant efficacy in meeting the endpoint of >30% decrease in parathyroid hormone (PTH) levels from baseline with minimal adverse events. Much more research needs to be done to expand and develop clinical pharmaceutical trials in the use of paricalcitol in children, especially in the younger age categories. This current study has done much to open the doors for future studies, with the caveat that it has been long coming and much more needs to be done to compensate for this delay in the treatment of children with CKD-MBD and cardiovascular and renal disease progression.

Gender-specific association of decreased estimated glomerular filtration rate and left vertical geometry in the general population from rural Northeast China

Background

Left ventricular hypertrophy (LVH) is common and associated with cardiovascular outcomes among patients with known chronic kidney disease (CKD). However, the link between decreased estimated glomerular filtration rate (eGFR) and left ventricular (LV) geometry remains poorly explored in general population. In this study, we examined the gender-specific association between eGFR and LVH in the general population from rural Northeast China.

Methods

This survey was conducted from July 2012 to August 2013. A total of 10907 participants (5,013 men and 5,894 women) from the rural Northeast China were randomly selected and examined. LV mass index (LVMI) was used to define LVH (LVMI > 46.7 g/m^2.7 in women; > 49.2 g/m^2.7 in men). LV geometry was defined as normal, or with concentric remodeling, eccentric or concentric hypertrophy, according to relative wall thickness (RWT) and LVMI. Mildly decreased eGFR was defined as eGFR ≥ 60 and < 90 ml/min/1.73 m², and moderate-severely decreased eGFR was defined as eGFR < 60 ml/min/1.73 m².

Results

As eGFR decreased, LVH showed a gradual increase in the entire study population. Multivariate analysis revealed a gender-specific relationship between eGFR and LV geometry. Only in men, mildly decreased eGFR was associated with concentric remodeling [odds ratio (OR): =1.58; 95% CI: 1.14–2.20; P < 0.01] and concentric LVH OR = 1.63; 95% CI: 1.15–2.31; P < 0.01). And only in men, moderate-severely decreased eGFR was a risk factor for concentric LVH (OR = 4.56; 95% CI: 2.14–9.73; P < 0.001) after adjusting for confounding factors.

Conclusions

These findings suggested that decreased eGFR was a risk factor for LV geometry in men, and a gender-specific difference should be taken into account in clinical practice.

Cardiovascular Phenotypes in Children with CKD: The 4C Study

BACKGROUND AND OBJECTIVES

Cardiovascular disease is the most important comorbidity affecting long-term survival in children with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Cardiovascular Comorbidity in Children with CKD Study is a multicenter, prospective, observational study in children ages 6-17 years old with initial GFR of 10-60 ml/min per 1.73 m2. The cardiovascular status is monitored annually, and subclinical cardiovascular disease is assessed by noninvasive measurements of surrogate markers, including the left ventricular mass index, carotid intima-media thickness, and central pulse wave velocity. We here report baseline data at study entry and an explorative analysis of variables associated with surrogate markers.

RESULTS

A total of 737 patients were screened from October of 2009 to August of 2011 in 55 centers in 12 European countries, and baseline data were analyzed in 688 patients. Sixty-four percent had congenital anomalies of the kidney and urinary tract; 26.1% of children had uncontrolled hypertension (24-hour ambulatory BP monitoring; n=545), and the prevalence increased from 24.4% in CKD stage 3 to 47.4% in CKD stage 5. The prevalence of left ventricular hypertrophy was higher with each CKD stage, from 10.6% in CKD stage 3a to 48% in CKD stage 5. Carotid intima-media thickness was elevated in 41.6%, with only 10.8% of patients displaying measurements below the 50th percentile. Pulse wave velocity was increased in 20.1%. The office systolic BP SD score was the single independent factor significantly associated with all surrogate markers of cardiovascular disease. The intermediate end point score (derived from the number of surrogate marker measurements >95th percentile) was independently associated with a diagnosis of congenital anomalies of the kidney and urinary tract, time since diagnosis of CKD, body mass index, office systolic BP, serum phosphorus, and the hemoglobin level.

CONCLUSIONS

The baseline data of this large pediatric cohort show that surrogate markers for cardiovascular disease are closely associated with systolic hypertension and stage of CKD.

Myocardial dysfunction occurs prior to changes in ventricular geometry in mice with chronic kidney disease (CKD)

Uremic cardiomyopathy is responsible for high morbidity and mortality rates among patients with chronic kidney disease (CKD), but the underlying mechanisms contributing to this complex phenotype are incompletely understood. Myocardial deformation analyses (ventricular strain) of patients with mild CKD have recently been reported to predict adverse clinical outcome. We aimed to determine if early myocardial dysfunction in a mouse model of CKD could be detected using ventricular strain analyses. CKD was induced in 5-week-old male 129X1/SvJ mice through partial nephrectomy (5/6Nx) with age-matched mice undergoing bilateral sham surgeries serving as controls. Serial transthoracic echocardiography was performed over 16 weeks following induction of CKD. Invasive hemodynamic measurements were performed at 8 weeks. Gene expression and histology was performed on hearts at 8 and 16 weeks. CKD mice developed decreased longitudinal strain (-25 ± 4.2% vs. -29 ± 2.3%; P = 0.01) and diastolic dysfunction (E/A ratio 1.2 ± 0.15 vs. 1.9 ± 0.18; P < 0.001) compared to controls as early as 2 weeks following 5/6Nx. In contrast, ventricular hypertrophy was not apparent until 4 weeks. Hearts from CKD mice developed progressive fibrosis at 8 and 16 weeks with gene signatures suggestive of evolving heart failure with elevated expression of natriuretic peptides. Uremic cardiomyopathy in this model is characterized by early myocardial dysfunction which preceded observable changes in ventricular geometry. The model ultimately resulted in myocardial fibrosis and increased expression of natriuretic peptides suggestive of progressive heart failure.

Assessing longitudinal trends in cardiac function among pediatric patients with chronic kidney disease

BACKGROUND

Left ventricular diastolic dysfunction (LVDD) is an early marker of cardiac disease in pediatric chronic kidney disease (CKD), but few studies have analyzed longitudinal trends. We conducted a prospective 3-year follow-up study in pediatric CKD and kidney transplant (CKD-T) patients.

METHODS

The patient cohort comprised 30 CKD and 42 CKD-T patients. The results of annual clinical and echocardiographic analyses using tissue Doppler imaging (TDI) and pulse wave Doppler (PWD) were assessed, and associations to predictive risk factors were studied using multivariate modeling.

RESULTS

The mean age of CKD and CKD-T patients at inclusion was 9.8 ± 4.4 and 11.8 ± 4.3 years, respectively; the glomerular filtration rate was 35.3 ± 18.3 and 60.3 ± 18.8 mL/min/1.73 m(2), respectively. The prevalence of left ventricular diastolic dysfunction (LVDD), as assessed using TDI (lateral z-score e') was 7.1 and 12.5 % in CKD and CKD-T patients, respectively; the corresponding values with PWD E were 3.3 and 2.4 %, respectively. In unadjusted analyses, both TDI and PWD markers of diastolic function worsened over the follow-up period; following adjustments, an elevated systolic ambulatory blood pressure was the most important predictor of cardiac disease.

CONCLUSIONS

Children with CKD show early signs of LVDD, with TDI being more sensitive than PWD in terms of diagnostic potential. An increased ambulatory systolic blood pressure predicted progression in diastolic function, suggesting opportunities for future interventions.

Diagnosis, Epidemiology, and Management of Hypertension in Children

National guidelines for the diagnosis and management of hypertension in children have been available for nearly 40 years. Unfortunately, knowledge and recognition of the problem by clinicians remain poor. Prevalence estimates are highly variable because of differing standards, populations, and blood pressure (BP) measurement techniques. Estimates in the United States range from 0.3% to 4.5%. Risk factors for primary hypertension include overweight and obesity, male sex, older age, high sodium intake, and African American or Latino ancestry. Data relating hypertension in childhood to later cardiovascular events is currently lacking. It is known that BP in childhood is highly predictive of BP in adulthood. Compelling data about target organ damage is available, including the association of hypertension with left ventricular hypertrophy, carotid-intima media thickness, and microalbuminuria. Guidelines from both the United States and Europe include detailed recommendations for diagnosis and management. Diagnostic standards are based on clinic readings, ambulatory BP monitoring is useful in confirming diagnosis of hypertension and identifying white-coat hypertension, masked hypertension, and secondary hypertension, as well as monitoring response to therapy. Research priorities include the need for reliable prevalence estimates based on diverse populations and data about the long-term impact of childhood hypertension on cardiovascular morbidity and mortality. Priorities to improve clinical practice include more education among clinicians about diagnosis and management, clinical decision support to aid in diagnosis, and routine use of ambulatory BP monitoring to aid in diagnosis and to monitor response to treatment.

Evidence-based guidelines for the management of hypertension in children with chronic kidney disease

Hypertension is common in children with chronic kidney disease and early evidence suggests that it is a modifiable risk factor for renal and cardiovascular outcomes. Recommendations for blood pressure management in children with chronic kidney disease can be found in various clinical practice guidelines including the 4th Task Force Report, the European Society of Hypertension pediatric recommendations, and the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (K/DOQI) and Kidney Disease: Improving Global Outcomes (KDIGO) guidelines for the management of blood pressure in chronic kidney disease. Unfortunately, as pediatric trial evidence is limited, there are discrepancies in the recommendations that may lead to inconsistent clinical care and practice variation. This article reviews the strength of evidence behind each of the clinical practice guideline recommendations regarding blood pressure assessment, treatment targets, and first-line antihypertensive medications. The benefits and cautions of use of clinical practice guidelines are described with emphasis on the importance of reading beyond the summary statements.

Relationship of FGF23 to indexed left ventricular mass in children with non-dialysis stages of chronic kidney disease

BACKGROUND

The aim of this study was to evaluate the association of serum intact fibroblast growth factor 23 (FGF23) concentrations with indexed left ventricular mass in children with non-dialysis stages 3-5 of chronic kidney disease (CKD).

METHODS

The study cohort comprised 83 children (51 boys; mean age 12.1 ± 3.2 years) with a mean estimated glomerular filtration rate (eGFR) of 32.3 ± 14.6 ml/min/1.73 m(2) who underwent clinic and ambulatory blood pressure measurement (ABPM), echocardiography and evaluation of biochemical markers of CKD-associated mineral bone disease.

RESULTS

The mean left ventricular mass index (LVMI) was 35.9 ± 8.5 g/m(2.7) (± standard deviation), with 30 (36.1 %) children showing left ventricular hypertrophy (LVH), all eccentric, as defined using age-specific criteria. For all subjects, the mean FGF23 concentration was 142.2 ± 204.4 ng/l and the normalised distribution following log transformation was 1.94 ± 0.39. There was significant univariate correlation of LVMI with GFR, body mass index (BMI) z-score and calcium intake, but not with 24-h systolic ABPM z-score, log intact parathyroid hormone or log FGF23. On multivariate analysis following adjustment for confounders, only elemental calcium content (g/kg/day) estimated from prescribed calcium-based phosphate binder dose (β = 154.9, p < 0.001) and BMI z-score (β = 2.397, p = 0.003) maintained a significant positive relationship with LVMI (model r (2) = 0.225).

CONCLUSIONS

We observed no significant relationship of FGF23 with LVMI. Larger studies in children are needed to clarify the roles of calcium-containing phosphate binders and FGF23 with LV mass and their roles in the evolution of the development of adverse cardiovascular outcomes.

The role of bone in CKD-mediated mineral and vascular disease

Cardiovascular disease is the leading cause of death in pediatric patients with chronic kidney disease (CKD), and vascular calcifications start early in the course of CKD. Based on the growing body of evidence that alterations of bone and mineral metabolism and the therapies designed to treat the skeletal consequences of CKD are linked to cardiovascular calcifications, the Kidney Disease, Improving Global Outcomes (KDIGO) working group redefined renal osteodystrophy as a systemic disorder of mineral and bone metabolism due to CKD, and this newly defined disorder is now known as "chronic kidney disease-mineral bone disorder (CKD-MBD)". Elevated fibroblast growth factor 23 (FGF23), a bone-derived protein, is the first biochemical abnormality to be associated with CKD-MBD, and high FGF23 levels correlate with increased cardiovascular morbidity and mortality, suggesting that bone is central to both initiating and perpetuating the abnormal mineral metabolism and vascular disease in CKD. The current standard therapies for CKD-MBD affect FGF23 levels differently; non-calcium-based binders with or without concurrent use of dietary phosphate restriction reduce FGF23 levels, while calcium-based binders seem to either increase or have no effect on FGF23 levels. Active vitamin D sterols increase FGF23 levels, whereas therapy with calcimimetics decreases FGF23 levels. Thus, the appropriate therapy that will minimize the rise in FGF23 and prevent cardiovascular morbidity remains to be defined.