Early cardiac dysfunction in pediatric patients on maintenance dialysis and post kidney transplant

Decline in Left Ventricular Early Systolic Function with Worsening Kidney Function in Children with Chronic Kidney Disease: Insights from the 4C and HOT-KID Studies

INTRODUCTION

Adults with childhood-onset chronic kidney disease (CKD) have an increased risk of cardiovascular disease. First-phase ejection fraction (EF1), a novel measure of early systolic function, may be a more sensitive marker of left ventricular dysfunction than other markers in children with CKD.

OBJECTIVE

To examine whether EF1 is reduced in children with CKD.

METHODS

Children from the 4C and HOT-KID studies were stratified according to estimated glomerular filtration rate (eGFR). The EF1 was calculated from the fraction of left ventricular (LV) volume ejected up to the time of peak aortic flow velocity.

RESULTS

The EF1 was measured in children ages 10.9 ± 3.7 (mean ± SD) years, 312 with CKD and 63 healthy controls. The EF1 was lower, while overall ejection fraction was similar, in those with CKD compared with controls and decreased across stages of CKD (29.3% ± 3.7%, 23.5% ± 4.5%, 19.8% ± 4.0%, 18.5% ± 5.1%, and 16.7% ± 6.6% in controls, CKD 1, 2, 3, and ≥ 4, respectively, P < .001). The relationship of EF1 to eGFR persisted after adjustment for relevant confounders (P < .001). The effect size for association of measures of LV structure or function with eGFR (SD change per unit change in eGFR) was greater for EF1 (β = 0.365, P < .001) than for other measures: LV mass index (β = -0.311), relative wall thickness (β = -0.223), E/e' (β = -0.147), and e' (β = 0.141) after adjustment for confounders in children with CKD.

CONCLUSIONS

Children with CKD exhibit a marked and progressive decline in EF1 with falling eGFR. This suggests that EF1 is a more sensitive marker of LV dysfunction when compared to other structural or functional measures and that early LV systolic function is a key feature in the pathophysiology of cardiac dysfunction in CKD.

Right Ventricular Strain Analysis By Tissue Tracking Cardiac Magnetic Resonance Imaging In Pediatric Patients With End-Stage Renal Disease

PURPOSE

To investigate right ventricular (RV) volume and mass by cardiac magnetic resonance (CMR) and the added value of tissue tracking strain analysis as markers of RV dysfunction in pediatric patients with end-stage renal disease (ESRD) and preserved RV ejection fraction.

MATERIALS AND METHODS

Twenty-five children with ESRD and preserved RVEF (>50%) and 10 healthy control children were enrolled. Tissue tracking CMR was used to assess Global Longitudinal, circumferential (GCS), and radial short and long axes (GRS SAX and GRS LAX) RV strains in the patients group compared with controls. Correlations between strain parameters and other CMR parameters and clinical biomarkers were assessed. Binary logistic regression was used to test the independence of cofounders and detect their significance.

RESULTS

RV end-diastolic volume and mass (RVMi) were significantly higher in patients (97.2±19.3 mL/m 2 and 26.6±7gr/m 2 ) than control (71±7.8 mL/m 2 and 11.9±2 gr/m 2 , P values 0.000). All RV global strain parameters were significantly impaired in patients compared with control (all P values <0.05). RV Global Longitudinal was significantly correlated to LVEF (r=-0.416, P =0.039), LVEDVi (r=0.481, P =0.015), LVMi (r=0.562, P =0.004), and systolic blood pressure index (r=0.586, P =0.002). RV GRS (LAX) was significantly correlated to LV GCS (r=-0.462, P =0.020) and LV GRS (SAX) (r=0.454, P =0.023). GRS (SAX) and GCS demonstrated the highest diagnostic accuracy (area under curve: 0.82 and 0.81) to detect strain impairment. Univariate binary logistic regression with patients versus control as dependent variables identified LVMi, RV end-diastolic volume, RVMi, weight, body surface area, RV GCS, RV GRS (LAX), RV GRS (SAX), LV GCS, and LV GRS (SAX) as significantly correlated to patients with ESRD. When adjusted to other cofounders in the multivariable model, only RVMi remained as an independent significant cofounder (Odds ratio:0.395, P =0.046).

CONCLUSION

RV global strain, volume, and mass by CMR are markers of RV dysfunction in ESRD pediatric patients with preserved RVEF.

Arginine Dysregulation and Myocardial Dysfunction in a Mouse Model and Children with Chronic Kidney Disease

Cardiovascular disease is the leading cause of death in chronic kidney disease (CKD). Arginine, the endogenous precursor for nitric oxide synthesis, is produced in the kidneys. Arginine bioavailability contributes to endothelial and myocardial dysfunction in CKD. Plasma from 129X1/SvJ mice with and without CKD (5/6th nephrectomy), and banked plasma from children with and without CKD were analyzed for amino acids involved in arginine metabolism, ADMA, and arginase activity. Echocardiographic measures of myocardial function were compared with plasma analytes. In a separate experiment, a non-specific arginase inhibitor was administered to mice with and without CKD. Plasma citrulline and glutamine concentrations correlated with multiple measures of myocardial dysfunction. Plasma arginase activity was significantly increased in CKD mice at 16 weeks vs. 8 weeks (p = 0.002) and ventricular strain improved after arginase inhibition in mice with CKD (p = 0.03). In children on dialysis, arginase activity was significantly increased vs. healthy controls (p = 0.04). Increasing ADMA correlated with increasing RWT in children with CKD (r = 0.54; p = 0.003). In a mouse model, and children, with CKD, arginine dysregulation correlates with myocardial dysfunction.

A Single-Center Experience With Kidney Transplantation in Patients Who Had Low Left Ventricular Ejection Fraction

OBJECTIVES

Left ventricular hypertrophy is one of the most typical cardiac abnormalities detected in patients with end-stage renal disease. In patients with congestive heart failure, the most crucial factor determining patient survival is left ventricular ejection fraction. Herein, we present our experience with living donor kidney transplant recipients with a left ventricular ejection fraction of <50%.

MATERIALS AND METHODS

Patients who underwent living donor kidney transplant in our center between November 2008 and November 2021 and had pretransplant left ventricular ejection fraction <50% were included. All patients had dialysis the day before surgery. All patients underwent 2-dimensional echocardiograms after dialysis and were categorized according to New York Heart Association classification, pretransplant and on posttransplant day 5. Demographic parameters and additional data, including pretransplant and posttransplant day 5 New York Heart Association classification, left ventricular ejection fraction at 6 months, and graft survival at 6 months, as well as patient survival data, were analyzed.

RESULTS

Our study included 31 patients (mean age of 46.6 ± 18.3; range, 11-77 years). We found significant differences in New York Heart Association classifications before and after transplant, indicating that kidney transplant had a positive effect on pretransplant congestive heart failure in patients with low left ventricular ejection fraction (P = .001). The mean pretransplant left ventricular ejection fraction was 32 ± 9.9% (range, 1%-45%), whereas the mean 6-month posttransplant left ventricular ejection fraction was 52 ± 8.7% (range, 28%-63%) (P < .001). Both graft loss and all-cause mortality rates were 12.9%.

CONCLUSIONS

Low left ventricular ejection fraction is not a contraindication for kidney transplant. We suggest that myocardial scintigraphy should be performed in patients with end-stage renal disease and low left ventricular ejection fraction, and kidney transplant should be considered in those without ischemic findings.

Left Ventricular Strain Analysis by Tissue Tracking- Cardiac Magnetic Resonance for early detection of Cardiac Dysfunction in children with End-Stage Renal Disease

BACKGROUND

Cardiovascular disease is a major cause of morbidity and mortality in end-stage renal disease (ESRD). Reduction in left ventricular ejection fraction (LVEF) represents late left ventricle (LV) dysfunction. Cardiac MRI myocardial strain analysis is an alternative method for assessment of LV function.

PURPOSE

To investigate whether LV strain analysis is more sensitive than LVEF for early detection of systolic dysfunction in children with ESRD.

STUDY TYPE

Case control.

POPULATION

Thirty-two children with ESRD (median 14 years, 17 females) and 10 healthy control (median 12.5 years, 7 females).

FIELD STRENGTH AND SEQUENCES

A 1.5 T /retrospective ECG-gated steady-state free precession (SSFP).

ASSESSMENT

LVEF, and indexed LV mass (LVMi) and LV end-diastolic volume (LVEDVi) were measured. Using tissue tracking analysis, LV endocardial and epicardial contours were traced in short and long axes at end diastole to calculate global longitudinal (GLS), circumferential (GCS) and radial (GRS) strains.

STATISTICAL ANALYSIS

Cardiac MRI and strain parameters were compared between patients and control, and between subgroup with preserved LVEF and control by Student t-test/Mann Whitney test. Diagnostic accuracy was assessed by Receiver operating characteristic analysis. Strain as predictor of poor outcome (mortality, pulmonary edema, and/or heart failure) within 1-year follow up was investigated by binary logistic regression.

RESULTS

Compared to control, cardiac MRI LVEF, LVEDVi, LVMi, GLS, GCS and GRS were significantly impaired in patients. Patients with preserved LVEF had significantly higher LVEDVi, LVMi and significantly impaired GCS and GRS than control. Strain parameters were significantly correlated with LVEF, LVEDVi, and LVMi. GCS and GRS demonstrated greater diagnostic accuracy than GLS (area under curve: 0.89). LVEF, LVMi, GCS, and GRS were correlated with poor outcome.

CONCLUSION

Cardiac MRI tissue tracking could identify subclinical LV dysfunction in children with ESRD and still preserved LVEF. Furthermore, LV strain parameters (GCS and GRS) were correlated with future cardiovascular events.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

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.

A novel ultrasound technique to detect early chronic kidney disease

Chronic kidney disease (CKD) of unknown etiology is recognized as a major public health challenge and a leading cause of morbidity and mortality in the dry zone in Sri Lanka. CKD is asymptomatic and are diagnosed only in late stages. Evidence points to strong correlation between progression of CKD and kidney fibrosis. Several biochemical markers of renal fibrosis have been associated with progression of CKD. However, no marker is able to predict CKD consistently and accurately before being detected with traditional clinical tests (serum creatinine, and cystatin C, urine albumin or protein, and ultrasound scanning). In this paper, we hypothesize that fibrosis in the kidney, and therefore the severity of the disease, is reflected in the frequency spectrum of the scattered ultrasound from the kidney. We present a design of a simple ultrasound system, and a set of clinical and laboratory studies to identify spectral characteristics of the scattered ultrasound wave from the kidney that correlates with CKD. We believe that spectral parameters identified in these studies can be used to detect and stratify CKD at an earlier stage than what is possible with current markers of CKD.

A novel ultrasound technique to detect early chronic kidney disease

Chronic kidney disease (CKD) of unknown etiology is recognized as a major public health challenge and a leading cause of morbidity and mortality in the dry zone in Sri Lanka. CKD is asymptomatic and are diagnosed only in late stages. Evidence points to strong correlation between progression of CKD and kidney fibrosis. Several biochemical markers of renal fibrosis have been associated with progression of CKD. However, no marker is able to predict CKD consistently and accurately before being detected with traditional clinical tests (serum creatinine, and cystatin C, urine albumin or protein, and ultrasound scanning).

In this paper, we hypothesize that fibrosis in the kidney, and therefore the severity of the disease, is reflected in the frequency spectrum of the scattered ultrasound from the kidney. We present a design of a simple ultrasound system, and a set of clinical and laboratory studies to identify spectral characteristics of the scattered ultrasound wave from the kidney that correlates with CKD. We believe that spectral parameters identified in these studies can be used to detect and stratify CKD at an earlier stage than what is possible with current markers of CKD.

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.

Cardiovascular effects of metabolic syndrome after transplantation: convergence of obesity and transplant-related factors

Children are at increased risk of developing metabolic syndrome (MS) after kidney transplantation, which contributes to long-term cardiovascular (CV) morbidities and decline in allograft function. While MS in the general population occurs due to excess caloric intake and physical inactivity, additional chronic kidney disease and transplant-related factors contribute to the development of MS in transplant recipients. Despite its significant health consequences, the interplay of the individual components in CV morbidity in pediatric transplant recipients is not well understood. Additionally, the optimal methods to detect early CV dysfunction are not well defined in this unique population. The quest to establish clear guidelines for diagnosis is further complicated by genetic differences among ethnic groups that necessitate the development of race-specific criteria, particularly with regard to individuals of African descent who carry the apolipoprotein L1 variant. In children, since major CV events are rare and traditional echocardiographic measures of systolic function, such as ejection fraction, are typically well preserved, the presence of CV disease often goes undetected in the early stages. Recently, new noninvasive imaging techniques have become available that offer the opportunity for early detection. Carotid intima-media thickness and impaired myocardial strain detected by speckle tracking echocardiography or cardiac magnetic resonance are emerging as early and sensitive markers of subclinical CV dysfunction. These highly sensitive tools may offer the opportunity to elucidate subtle CV effects of MS in children after transplantation. Current knowledge and future directions are explored in this review.

Left Ventricular Hypertrophy in Pediatric Hypertension: A Mini Review

Adults with arterial hypertension (HTN) have stroke, myocardial infarction, end-stage renal disease (ESRD), or die at higher rates than those without. In children, HTN leads to target organ damage, which includes kidney, brain, eye, blood vessels, and heart, which precedes "hard outcomes" observed in adults. Left ventricular hypertrophy (LVH) or an anatomic and pathologic increase in left ventricular mass (LVM) in response to the HTN is a pediatric surrogate marker for HTN-induced morbidity and mortality in adults. This mini review discusses current definitions, clinically relevant methods of LVM measurements and normalization methods, its epidemiology, management, and issue of reversibility in children with HTN. Pediatric definition of LVH and abnormal LVM is not uniformed. With multiple definitions, prevalence of pediatric HTN-induced LVH is difficult to ascertain. In addition while in adults cardiac magnetic resonance imaging is considered "the gold standard" for LVM and LVH determination, pediatric data are limited to "special populations": ESRD, transplant, and obese children. We summarize available data on pediatric LVH treatment and reversibility and offer future directions in addressing LVH in children with HTN.

Assessment of Left Ventricular Mass and Hypertrophy by Cardiovascular Magnetic Resonance Imaging in Pediatric Hypertension

Cardiovascular magnetic resonance (CMR) imaging in adults is considered the gold standard for assessment of left ventricular mass (LVM) and left ventricular hypertrophy (LVH). The authors aimed to evaluate agreement of LVM measurements and LVH determination between echocardiography (ECHO) and CMR imaging in children with hypertension (HTN) confirmed by 24-hour ambulatory blood pressure monitoring (ABPM). The children (n=22) underwent contemporaneous ECHO, CMR imaging, and ABPM. Patients had a mean body mass index of 30.9±7.5 (kg/m2 ), and 81.8% had severe HTN. LVM measured by ECHO was 189.6±62.1 g and by CMR imaging was 164.6±44.7 g (P<.0001). Bland-Altman analysis revealed significant variability between ECHO and CMR imaging in the measurement of LVM. Interobserver error was higher with ECHO than with CMR imaging. ECHO had high sensitivity and low specificity in LVH determination. In conclusion, ECHO overestimates LVM and is less accurate in measuring LVM as compared with CMR imaging in children with HTN. Further prospective study using CMR imaging to assess LVM in children is warranted.

Left ventricular mass and systolic function in children with chronic kidney disease-comparing echocardiography with cardiac magnetic resonance imaging

BACKGROUND

Increased left ventricular mass (LVM) is an important risk marker of uremic cardiovascular disease. Calculation of LVM by echocardiography (Echo) relies on geometric assumptions and in adults on hemodialysis overestimates LVM compared to cardiac magnetic resonance (CMR). We compare both techniques in children with chronic kidney disease (CKD).

METHODS

Concurrent Echo and CMR was performed in 25 children with CKD (14 after kidney transplantation) aged 8-17 years.

RESULTS

Compared to normal children, CMR-LVM was increased (standard deviation score (SDS) 0.39 ± 0.8 (p = 0.03)), stroke volume and cardiac output decreased (SDS -1.76 ± 1.1, p = 0.002 and -1.11 ± 2.0, p = 0.001). CMR-LVM index but not Echo-LVMI correlated to future glomerular filtration rate (GFR) decline (r = -0.52, p = 0.01). Mean Echo-LVM was higher than CMR-LVM (117 ± 40 vs. 89 ± 29 g, p < 0.0001), with wide limits of agreement (-6.2 to 62.8 g). The Echo-CMR LVM difference increased with higher Echo-LVMI (r = 0.77, p < 0.0001). Agreement of classifying left ventricular hypertrophy was poor with Cohen's kappa of 0.08. Mean Echo and CMR-ejection fraction differed by 1.42% with wide limits of agreement (-12.6 to 15.4%).

CONCLUSIONS

Echo overestimates LVM compared to CMR, especially at higher LVM. Despite this, CMR confirms increased LVM in children with CKD. Only CMR-LVMI but not Echo-LVMI correlated to future GFR decline.

Myocardial Ischemia Assessment in Chronic Kidney Disease: Challenges and Pitfalls

Coronary artery disease is the leading cause of mortality and morbidity in the chronic kidney disease (CKD) population and often presents with atypical symptoms. Current diagnostic investigations of myocardial ischemia in CKD lack sensitivity and specificity or may have adverse effects. We present a case vignette and explore the challenges of diagnostic myocardial stress investigation in patients with CKD.

Left ventricular mass and cardiac function in a population of children with chronic kidney disease

BACKGROUND

Cardiovascular disease (CVD) is a common cause of morbidity and mortality in children with chronic kidney disease (CKD). Left ventricular hypertrophy (LVH) and diastolic dysfunction (LVDD) are early markers. The aims of this study were to evaluate (1) LVH and LVDD, using both conventional echocardiographic evaluation and Tissue Doppler Imaging (TDI), and (2) the correlation between cardiac disease and possible risk factors, in children with CKD.

METHODS

The study cohort comprised 34 paediatric patients with CKD and 34 healthy children (mean ± standard deviation: age 9 ± 4.6 and 8.2 ± 4.3 years, respectively). Thirteen (38 %) patients were in CKD stage 2, 15 (44 %) in stage 3 and six (18 %) in stage 4-5. LVH was defined as a left ventricular mass index (LVMI) of >95th percentile (38 g/h(2.7)).

RESULTS

Left ventricular hypertrophy was present in 13 patients (38 %). Diastolic function evaluated with TDI (E'/A' = early/late diastolic myocardial velocity) worsened with the reduction of glomerular filtration rate (p = 0.020). There was a positive correlation between LVMI and body mass index-standard deviation score (p = 0.020) and a negative correlation between E'/A' and serum phosphorus and calcium levels and their respective product (p = 0.004, p = 0.017, p < 0.001). The relaxation index E' was reduced in 68 % of patients.

CONCLUSION

Based on our results, TDI is a simple procedure and would appear to be a more accurate diagnostic tool than conventional echocardiography in the early diagnosis of LVDD.

BP control and left ventricular hypertrophy regression in children with CKD

In adult patients with CKD, hypertension is linked to the development of left ventricular hypertrophy, but whether this association exists in children with CKD has not been determined conclusively. To assess the relationship between BP and left ventricular hypertrophy, we prospectively analyzed data from the Chronic Kidney Disease in Children cohort. In total, 478 subjects were enrolled, and 435, 321, and 142 subjects remained enrolled at years 1, 3, and 5, respectively. Echocardiograms were obtained 1 year after study entry and then every 2 years; BP was measured annually. A linear mixed model was used to assess the effect of BP on left ventricular mass index, which was measured at three different visits, and a mixed logistic model was used to assess left ventricular hypertrophy. These models were part of a joint longitudinal and survival model to adjust for informative dropout. Predictors of left ventricular mass index included systolic BP, anemia, and use of antihypertensive medications other than angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Predictors of left ventricular hypertrophy included systolic BP, female sex, anemia, and use of other antihypertensive medications. Over 4 years, the adjusted prevalence of left ventricular hypertrophy decreased from 15.3% to 12.6% in a systolic BP model and from 15.1% to 12.6% in a diastolic BP model. These results indicate that a decline in BP may predict a decline in left ventricular hypertrophy in children with CKD and suggest additional factors that warrant additional investigation as predictors of left ventricular hypertrophy in these patients.