Tissue Doppler imaging predicts outcomes in hemodialysis patients with preserved left ventricular function

Impact of Hemodialysis on Left Ventricular-Arterial Coupling in End-Stage Renal Disease Patients

INTRODUCTION

As a key determinant of cardiovascular performance, vascular-arterial coupling (VAC) has been reported to be a predictor of clinical outcomes in various clinical scenarios. However, few studies have explored how acute fluid removal during hemodialysis (HD) impacts the interaction between cardiac function and the arterial system.

METHODS

We recruited 317 HD patients from an established renal dialysis unit for this cross-sectional study and a total of 285 were included in the final analyses. We measured left ventricle end-systolic elastance (Ees), the effective arterial elastance (Ea), and VAC before and after HD using noninvasive echocardiographic measurements. We also compared echocardiographic and hemodynamic parameters in ventriculo-arterial coupling and ventriculo-arterial uncoupling patients.

RESULTS

HD significantly altered partial ventricular and vascular function parameters such as blood pressure, left ventricular end-diastolic volume, stroke volume, left ventricular ejection fraction, and systemic vascular resistance index. Ea increased following HD from 3.5 ± 1.4 to 4.2 ± 1.8 mm Hg/mL (p < 0.0001), Ees increased following HD from 7.9 ± 5.5 to 9.2 ± 6.9 mm Hg/mL (p = 0.04), whereas VAC did not markedly alter as a result of HD. Ventriculo-arterial uncoupling was found to be related to abnormal cardiac structure and worse systolic function.

CONCLUSIONS

VAC obtained from echocardiography is likely to be load-independent and useful as a reliable index for stratifying the risk of cardiovascular diseases in HD patients. Further investigations on larger patient cohorts are needed to further validate our findings.

Hemodialysis Parameters and Pulse Wave Velocity

Aim

The study aimed to evaluate the acute effect of ultrafiltration on the mechanical properties of the aorta using brachial-ankle pulse wave velocity (PWV) before and after hemodialysis (HD).

Patients and Methods

This study included 80 patients who were on a long-term HD program. The input variables were anamnestic data, body composition monitor (BCM) parameters, and echocardiography findings. The assessment of hydration status was determined by BCM, whose work is based on the principle of multifrequency bioimpedance spectroscopy. Another diagnostic procedure was the use of an arteriograph apparatus to assess PWV and Augmentation Index (AIx). All measurements were performed before and after dialysis on the middle dialysis day of the week.

Results

The participants were divided into two groups based on hydration status: the experimental group consisted of 40 overhydrated participants and the control group consisted of 40 normovolemic participants. Statistically, the following BCM parameters correlated significantly positively with PWV: total body fat (r = 0.222; P < 0.05), overhydration (r = 0.290; P < 0.001), and relative overhydration (r = 0.290; P < 0.001). From echocardiography findings, only left atrial diameter correlated statistically significantly positively with PWV (r = 0.359; P < 0.001). Comparison of the mean PWV values within the experimental group before and after HD showed a statistically significant decrease from 14.32 ± 2.34 m/s to 8.72 ± 1.52 m/s (Z = 3.254; P = 0.0001). Mean PWV values within the control group did not decrease significantly from 13.39 ± 1.32 m/s to 10.39 ± 1.18 m/s (Z = 0.524; P = 0.742). If we compare the mean values of PWV between groups, then before HD treatment, there was no statistically significant difference between groups with PWV values in the experimental group of 14.32 ± 2.34 m/s and the control group of 13.39 ± 1.32 m/s (Z = 0.762; P = 0.852). According to the results of univariate regression analysis before and after HD treatment, only overhydration showed an absolute effect on PWV before and after HD.

Conclusion

Overhydration showed an effect on brachial-ankle PWV before and after HD, and brachial-ankle PWV should be followed in HD patients.

Frequency and risk factors of impaired left ventricular global longitudinal strain in patients with end-stage renal disease: a two-dimensional speckle-tracking echocardiographic study

Background

It has been identified that two-dimensional speckle-tracking imaging (2D-STI) enables the early detection of left ventricular (LV) systolic dysfunction. This study's objective was to evaluate the frequency of impaired LV global longitudinal strain (GLS) and investigate the factors in end-stage renal disease (ESRD) patients with preserved LV ejection fraction (LVEF) associated with the impaired GLS.

Methods

A total of 100 ESRD patients with preserved LVEF who underwent transthoracic echocardiography (TTE) were studied. The GLS was calculated as the average of peak longitudinal strain from 18 myocardial segments obtained utilizing the three-standard apical imagings. According to a predefined cutoff, a GLS absolute value of less than 18% was considered subclinical LV systolic dysfunction.

Results

Impaired LV GLS <18% was detected in 58 participants (58/100, 58%). Multivariate analysis exhibited that increased LV mass index was independently associated with impaired GLS <18% [odds ratio (OR): 1.028, 95% confidence interval (CI): 1.004-1.052, P=0.020]. For sequential logistic regression models, model 1, based on parameters included in multivariate logistic regression (χ²=30.0), was improved by the addition of the LV mass index (χ²=37.4, P<0.01).

Conclusions

The frequency of impaired LV GLS in ESRD patients with preserved LVEF was relatively high. An increased LVEF was independently associated with impaired LV GLS.

Clinical significance of central systolic blood pressure in LV diastolic dysfunction and CV mortality

BACKGROUND AND AIMS

Cardiovascular (CV) disease is the major cause of death in patients with end-stage kidney disease (ESKD). Left ventricular (LV) diastolic dysfunction reflects LV pressure overload and is common in patients with ESKD. Recently, there have been studies on the usefulness of central blood pressure (BP); however, the relationship between central BP and LV diastolic dysfunction is not clear in dialysis patients with preserved systolic function. The purpose of this study was to investigate the clinical implication of central BP on LV diastolic dysfunction and CV mortality in the ESKD patients with preserved LV systolic function.

METHODS

This prospective observational cohort study investigated the effect of LV diastolic dysfunction on CV mortality in the ESKD patients with preserved systolic function using echocardiography. Vascular calcification was evaluated using the abdominal aortic calcification score, and aortic stiffness was determined by measuring pulse wave velocity (PWV). The predictors of CV mortality were analyzed using Cox proportional hazard analysis.

RESULTS

The subjects were comprised of 61 patients, with an average age of 54 years, 20 males (32.8%), and 25 diabetics (41.0%). There were 39 patients on hemodialysis and 22 patients receiving peritoneal dialysis treatment. During the mean follow-up period of 79.3 months, 16 patients (26.2%) died, and 7 patients (11.4%) died of CV events. The central systolic BP and diabetes were independent risk factors for LV diastolic dysfunction. In addition, patients with LV diastolic dysfunction had an increased CV mortality. When left atrial volume index and PWV were adjusted, the E/E' ratio was found to be a predictor of CV mortality.

CONCLUSIONS

Central systolic BP and diabetes were found to be significant risk factors for LV diastolic dysfunction. LV diastolic dysfunction can independently predict CV mortality in dialysis patients with preserved LV systolic function.

The effect of spironolactone on diastolic function in haemodialysis patients

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent in patients on maintenance haemodialysis (HD) and lacks effective treatment. We investigated the effect of spironolactone on cardiac structure and function with a specific focus on diastolic function parameters. The MiREnDa trial examined the effect of 50 mg spironolactone once daily versus placebo on left ventricular mass index (LVMi) among 97 HD patients during 40 weeks of treatment. In this echocardiographic substudy, diastolic function was assessed using predefined structural and functional parameters including E/e’. Changes in the frequency of HFpEF were analysed using the comprehensive ‘HFA-PEFF score’. Complete echocardiographic assessment was available in 65 individuals (59.5 ± 13.0 years, 21.5% female) with preserved left ventricular ejection fraction (LVEF > 50%). At baseline, mean E/e’ was 15.2 ± 7.8 and 37 (56.9%) patients fulfilled the criteria of HFpEF according to the HFA-PEFF score. There was no significant difference in mean change of E/e’ between the spironolactone group and the placebo group (+ 0.93 ± 5.39 vs. + 1.52 ± 5.94, p = 0.68) or in mean change of left atrial volume index (LAVi) (1.9 ± 12.3 ml/m² vs. 1.7 ± 14.1 ml/m², p = 0.89). Furthermore, spironolactone had no significant effect on mean change in LVMi (+ 0.8 ± 14.2 g/m² vs. + 2.7 ± 15.9 g/m²; p = 0.72) or NT-proBNP (p = 0.96). Treatment with spironolactone did not alter HFA-PEFF score class compared with placebo (p = 0.63). Treatment with 50 mg of spironolactone for 40 weeks had no significant effect on diastolic function parameters in HD patients.

The trial has been registered at clinicaltrials.gov (NCT01691053; first posted Sep. 24, 2012).