Left ventricular function by 'conventional' and 'tissue Doppler' echocardiography in paediatric dialysis patients

Get to the heart of pediatric kidney transplant recipients: Evaluation of left- and right ventricular mechanics by three-dimensional echocardiography

Background

Kidney transplantation (KTX) markedly improves prognosis in pediatric patients with end-stage kidney failure. Still, these patients have an increased risk of developing cardiovascular disease due to multiple risk factors. Three-dimensional (3D) echocardiography allows detailed assessment of the heart and may unveil distinct functional and morphological changes in this patient population that would be undetectable by conventional methods. Accordingly, our aim was to examine left- (LV) and right ventricular (RV) morphology and mechanics in pediatric KTX patients using 3D echocardiography.

Materials and methods

Pediatric KTX recipients (n = 74) with median age 20 (14–26) years at study enrollment (43% female), were compared to 74 age and gender-matched controls. Detailed patient history was obtained. After conventional echocardiographic protocol, 3D loops were acquired and measured using commercially available software and the ReVISION Method. We measured LV and RV end-diastolic volumes indexed to body surface area (EDVi), ejection fraction (EF), and 3D LV and RV global longitudinal (GLS) and circumferential strains (GCS).

Results

Both LVEDVi (67 ± 17 vs. 61 ± 9 ml/m2; p < 0.01) and RVEDVi (68 ± 18 vs. 61 ± 11 ml/m2; p < 0.01) were significantly higher in KTX patients. LVEF was comparable between the two groups (60 ± 6 vs. 61 ± 4%; p = NS), however, LVGLS was significantly lower (−20.5 ± 3.0 vs. −22.0 ± 1.7%; p < 0.001), while LVGCS did not differ (−29.7 ± 4.3 vs. −28.6 ± 10.0%; p = NS). RVEF (59 ± 6 vs. 61 ± 4%; p < 0.05) and RVGLS (−22.8 ± 3.7 vs. −24.1 ± 3.3%; p < 0.05) were significantly lower, however, RVGCS was comparable between the two groups (−23.7 ± 4.5 vs. −24.8 ± 4.4%; p = NS). In patients requiring dialysis prior to KTX (n = 64, 86%) RVGCS showed correlation with the length of dialysis (r = 0.32, p < 0.05).

Conclusion

Pediatric KTX patients demonstrate changes in both LV and RV morphology and mechanics. Moreover, the length of dialysis correlated with the contraction pattern of the right ventricle.

Subclinical cardiac dysfunction in pediatric kidney transplant recipients identified by speckle-tracking echocardiography

BACKGROUND

Kidney transplantation (KTx) improves prognosis in children with kidney failure; still, these patients are prone to cardiovascular damage due to multiple risk factors. Our aim was to assess myocardial structure and function in pediatric KTx by conventional and speckle-tracking echocardiography (STE) in association with established cardiovascular risk factors.

METHODS

Forty-two KTx and 39 healthy age- and gender-matched children were evaluated. KTx recipients were further categorized according to the control of hypertension assessed by 24-h ambulatory blood pressure monitoring (ABPM). Subjects underwent pulse wave velocity (PWV) measurement, conventional echocardiography, and 2-dimensional STE. Left and right ventricular (LV, RV) global longitudinal strain (GLS), and LV circumferential strain (GCS) were measured. Glomerular filtration rate (eGFR) was calculated according to the Schwartz formula.

RESULTS

KTx patients had increased blood pressure and arterial stiffness. LV ejection fraction (EF) was preserved along with elevated LV mass index (LVMi) while LVGLS was significantly lower, whereas LVGCS and RVGLS were increased in KTx. Uncontrolled hypertensives had lower LVGLS compared to those with controlled hypertension. Using multiple forward stepwise regression analysis, 24-h SBP and relative wall thickness (RWT) were independent determinants of LVMi, whereas antihypertensive therapy, eGFR, and HOMA-IR were independent determinants of LVGLS.

CONCLUSIONS

Cardiac morphology and function show distinct changes after KTx. Along with comparable ventricular volumes, LV hypertrophy and subclinical myocardial dysfunction are present. Control of hypertension and kidney graft function are major factors of LV performance. STE may be useful to reveal early myocardial dysfunction in pediatric KTx. A higher resolution version of the Graphical abstract is available as Supplementary information.

Left ventricular dysfunction by conventional and tissue Doppler echocardiography in pediatric hemodialysis patients: relation with plasma brain natriuretic peptide levels

INTRODUCTION

Tissue Doppler imaging (TDI) is a relatively new echocardiography method in children with chronic kidney disease (CKD). The aims of this study were to evaluate left ventricular (LV) diastolic function in pediatric CKD patients using conventional pulsed-wave Doppler echocardiography (cPWD) and TDI methods and correlate them with BNP levels.

MATERIAL AND METHODS

Thirty children on regular hemodialysis (HD) were included. Left ventricular systolic and diastolic indices and BNP levels were measured immediately before and after HD.

RESULTS

After HD, LV and left atrium diameters were significantly decreased (p < 0.001 and p < 0.001, respectively). Transmitral E velocity and E/A ratio decreased (p < 0.001 and p < 0.001, respectively). Also, there were significant decreases in the early diastolic velocity E' of LV wall, septal wall, and anterior wall (p = 0.001, p = 0.004 and p < 0.001, respectively). Mean E/E' ratio and ratios of septal and lateral walls were decreased significantly (p = 0.004, p = 0.002 and p = 0.017, respectively). BNP levels decreased significantly during HD when comparing concentrations before and after HD (p < 0.001). BNP strongly correlated with LV diastolic function indices (before HD: mean E/E' (r = 0.401, p = 0.028), lateral E/E" (r = 0.291, p = 0.025), septal E'(r = -0.398, p = 0.029), lateral wall E' (r = -0.452, p = 0.012) and mean E' (r = -0.469, p = 0.009), after HD: mean E/E' (r = 0.38, p = 0.038) and lateral E/E" (r = 0.474, p = 0.008) and lateral wall E' (r = -0.270, p = 0.037)).

CONCLUSIONS

The cPWD and TDI-derived LV indices are influenced by HD. The diagnostic utility of BNP in the presence of deteriorating renal function may be compromised to some extent.

Low triiodothyronine is associated with elevation of N-terminal pro-brain natriuretic peptide (NT-proBNP) and mortality in dialysis patients

BACKGROUND

Low thyroid hormone (TH) levels and myocardial damage are common in dialysis patients and are associated with mortality. However, little is known about the role of THs on myocardial damage as has been described in primary thyroid diseases. The aim of this study was to explore the potential relationship between low total triiodothyronine (total T3) and biomarkers of myocardial damage and the effect of their interaction on mortality, to ascertain if cardiovascular damage is the link between low THs and the risk of death in dialysis patients with CKD.

MATERIAL AND METHODS

TH plasma levels, nutritional markers, inflammation and myocardial damage were studied in 296 patients undergoing peritoneal dialysis or haemodialysis, who were followed up for 16 months to ascertain the association between biochemical variables and mortality.

RESULTS

Low total T3 levels were found in 45% of patients, which was inversely correlated with C-reactive protein (CRP) and NT-proBNP, and directly correlated with albumin and transferrin. Diabetes, CRP and total T3 were risk factors for all-cause mortality, and CRP, NT-proBNP and total T3 for cardiovascular mortality.

CONCLUSIONS

Low total T3 levels are common in dialysis patients and are associated with inflammation, malnutrition and myocardial damage. The latter may be the link between low THs and all-cause and cardiovascular mortality.

Children with chronic renal disease undergoing dialysis or conservative treatment--differences in structural and functional echocardiographic parameters

Cardiac disease frequently occurs in children with chronic kidney disease (CKD) undergoing dialysis (DI), but it is not well studied in patients undergoing conservative treatment (CT). The aim of our study was to use echocardiography to analyze and compare the cardiac involvement of children with CKD undergoing DI or CT.

METHODS

Seventy-one children with CKD were included; 41 undergoing DI and 30 undergoing CT. There were 33 controls. Measurements of arterial pressure and structural and functional echocardiographic variables were obtained; the children were followed up for 18 months. Tests of comparison and multiple regression were used; significant if P < 0.05.

RESULTS

Arterial hypertension (AH) was present in 37 of 71 (52%) children with CKD: 27 (65.8%) in DI and 10 (33.3%) in CT (X2 = 8.7; P = 0.003). An abnormal left ventricular geometric pattern was present in 37/41 (90.3%) undergoing DI, 33 had left ventricular hypertrophy (LVH), and in 14/30 (46.7%) undergoing CT, 5 had LVH. Ejection fraction was normal in all groups; diastolic function alteration (DFA) occurred in 28/41 (68.3%) children on DI and in 10/30 (33.3%) on CT (X2 = 9.2; P = 0.002). For children with CKD, DI (P = 0.002) and hypertension (P = 0.04) were associated with LVH; among those on DI, only AH was associated with LVH (P = 0.02). During the follow-up, 18 (43.9%) children undergoing DI had at least one cardiovascular event.

CONCLUSION

Children with CKD undergoing CT had less cardiac involvement than those undergoing DI. LVH was associated with DI and AH in all children with CKD and with AH in those on DI.

Acute Haemodialysis-induced Changes in Tissue Doppler Echocardiography Parameters

BACKGROUND

Tissue Doppler imaging (TDI) is a method that determines the tissue motion and velocity within the myocardium.

AIMS

To characterize acute haemodialysis (HD)-induced changes in TDI-derived indices for patients that have end-stage renal disease (ESRD).

STUDY DESIGN

Cross sectional study.

METHODS

Conventional echocardiography and TDI methods were applied to study ESRD patients (n=58) before and after HD. Pulmonary venous flow, mitral inflow, and TDI signals of the lateral and septal mitral annulus were examined for the determination of altered left-ventricular diastolic filling parameters. Flow velocities from early- (E) and late-atrial (A) peak transmitral; peak pulmonary vein systolic (S) and diastolic (D); and myocardial peak systolic (Sm) and peak early (Em) and late (Am) diastolic mitral annular velocities were also assessed for changes.

RESULTS

Transmitral E and A velocities and the E/A ratio decreased significantly after HD (p<0.001). Pulmonary vein S (p<0.001) and D (p<0.001) velocities decreased, and S/D ratios increased significantly (p=0.027). HD led to a reduction in septal Em (p<0.001), lateral Em (p=0.006), and Am (p<0.001) velocities. Contrary to the decreases in Em and Am, the Em/Am ratio remained unchanged.

CONCLUSION

A single HD session was associated with an acute deterioration in the diastolic parameters. Since the Em/Am ratio remained unchanged, we conclude that this index is a relatively load-independent measure of diastolic function in HD patients.

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.

Bioimpedance analysis and cardiovascular status in pediatric patients on chronic hemodialysis

Bioimpedance analysis (BIA) is reported to be useful in assessing dry weight (DW) in patients on hemodialysis (HD), but its exact role has never been clearly defined. We reviewed our experience of using the BIA measure of reactance (Xc) in pediatric patients on chronic HD. Our approach is currently based on identifying a range of patient-specific Xc values at which a child can be considered at DW according to a multidisciplinary assessment. Values lower than the patient-specific limit suggests the need for a reduction in DW, whereas values higher than the limit suggest that DW should be increased. The accuracy of our approach was retrospectively assessed by analyzing the left ventricular mass index (LVMI) and the incidence of pulmonary edema (PE) in two groups: The first consisted of 13 patients (median age 15.6 years) on dialysis in 2007, before the introduction of the BIA-based approach; the second included 18 patients (median 14.8 years) on dialysis in 2011. In 2007, three children experienced four episodes of PE, whereas no PE occurred in 2011. The median LVMI was 56.8 g/m(2.7) in 2007, and 44.5 g/m(2.7) in 2011 (P < 0.05). The percentage of patients with LV hypertrophy (LVMI>38.5 g/m(2.7)) was 92.3% in 2007 and 61.1% in 2011 (P < 0.05). There were no between-group differences in terms of blood pressure, antihypertensive medications, percentage of symptomatic sessions, or biochemistry. In conclusion, a simple approach based on BIA may be useful in assessing DW in pediatric patients on HD, and thus improve their cardiovascular status.

Assessment of late cardiotoxicity of pirarubicin (THP) in children with acute lymphoblastic leukemia

BACKGROUND

Pirarubicin (tetrahydropyranyl-adriamycin: THP) is a derivative of doxorubicin with reportedly less cardiotoxicity in adults. However no studies of cardiotoxicity in children treated with THP have been reported. This study was performed to assess the THP-induced cardiotoxicity for children with acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

This study comprised 61 asymptomatic patients aged from 7.6 to 25.7 years old. Median follow-up time after completion of anthracycline treatment was 8.1 years (range: 1.7-12.5). The cumulative dose of THP ranged from 120 to 740 mg/m(2) with a median of 180 mg/m(2) . Patients underwent electrocardiogram (ECG), echocardiography, the 6-min walk test (6MWT), and measurements of serum brain natriuretic peptide (BNP) before and after exercise.

RESULTS

All subjects showed normal left ventricular function assessed by echocardiography. Ventricular premature contraction in Holter ECG and reduced exercise tolerance in the 6MWT were detected in 2/46 (3.3%) and 5/41(12.2%), respectively. Abnormal BNP levels were detected in 6/60 (10%) both before and after exercise. The cumulative dose of THP was significantly correlated with BNP levels after exercise (r = 0.27, P = 0.03), but not with any other cardiac measurements. Further analysis revealed that subjects with a high cumulative dose ≧300 mg/m(2) had significantly higher BNP levels after exercise compared with subjects with a low cumulative dose <300 mg/m(2) (P = 0.04).

CONCLUSIONS

No significant cardiac dysfunction was detected in long-term survivors who received THP treatment. The use of post-exercise BNP level to indicate high cardiotoxicity risk should be verified by further study.

Relationship of brain natriuretic peptide concentrations to left ventricular function and adverse outcomes in children with end-stage renal disease undergoing hemodialysis

B-type natriuretic peptide (BNP) is a biomarker of cardiovascular disease that is common in adults with chronic kidney disease (CKD). However, in children with CKD, the range and predictive power of BNP concentrations are not known. We aimed to determine the effect of HD on BNP, as well as the prognostic impact of BNP, in end-stage renal disease (ESRD) children undergoing hemodialysis (HD). Thirty-five children with chronic renal failure (16 boys age 12.1 ± 3.7 years) on maintenance HD were included. BNP level was measured, and Doppler echocardiography was performed 30 min before (pre-HD BNP) and 30 min after (post-HD BNP) HD in each patient. An adverse event was defined as all-cause death and heart failure hospitalization. The median pre-HD BNP, the post-HD BNP, and the change in BNP were, respectively, 240 pg/ml (72 to 3346), 318 pg/ml (79 to 3788), and 9 pg/ml (-442 to 1889). Pre-HD BNP concentration was negatively correlated with left ventricular (LV) ejection fraction (r = -0.41, P = 0.018). During a mean follow-up of 39 ± 14 months, 6 patients died, and 3 were hospitalized for heart failure. Using univariate analysis, BNP before and after HD as well as Doppler tissue imaging velocities had a strong graded relationship with adverse events. Cox proportional hazards model demonstrated that pre-HD body weight (P = 0.008), pre-HD BNP (P = 0.011), and post-HD BNP (P = 0.038) remained independent predictors of adverse outcome. Even in case of ESRD, BNP still strongly correlated with LV systolic and diastolic dysfunction and was associated with mortality in HD children.

Atherosclerosis in CKD: differences from the general population

The prevalence of cardiovascular morbidity and mortality is higher in patients with chronic kidney disease (CKD)-especially those with end-stage renal disease-than in the general population. The contribution of atherosclerosis to cardiovascular disease in patients with CKD remains unclear. Researchers in the 1970s proposed that atherosclerosis was the main cause of cardiovascular disease in patients with CKD and that its progression, based on observations of patients on long-term dialysis, was accelerated by the uremic state. Subsequent reports, however, favor the involvement of other mechanisms, such as arteriosclerosis (characterized by vascular stiffening), vascular calcification, 'myocyte/capillary mismatch', congestive cardiomyopathy, and sudden cardiac death. Imaging and morphological studies have contributed to our understanding of the pathogenesis and progression of cardiovascular disease associated with CKD. Based on clinical and experimental findings, we hypothesize the following: the initial cardiovascular abnormalities in the CKD setting include arteriosclerosis, left ventricular diastolic dysfunction, and left ventricular hypertrophy, abnormalities which, in adult patients, are often accompanied by atherosclerosis. The prevalence of atherosclerosis increases with age and is aggravated, but not specifically induced, by CKD. The cardiovascular events associated with atherosclerosis are more often fatal in patients with CKD than in individuals without CKD.