Volume Balance in Chronic Kidney Disease: Evaluation Methodologies and Innovation Opportunities

Non-infectious complications of peritoneal dialysis in children

Peritoneal dialysis (PD) remains a cornerstone treatment for children with stage 5 chronic kidney disease, offering significant benefits in terms of quality of life and patient autonomy compared to hemodialysis. Recent advances in care protocols, particularly in infection prevention, have led to a substantial reduction in peritonitis and other infectious complications in pediatric patients on PD. Despite these improvements, non-infectious complications continue to pose significant challenges to the long-term efficacy of PD. Mechanical issues, such as catheter malposition and dysfunction, are common and can lead to discomfort and diminished dialysis efficiency. A more serious concern is peritoneal membrane failure, which results from prolonged PD, particularly with glucose-based solutions, and recurrent peritonitis, leading to structural changes in the membrane. Encapsulating peritoneal sclerosis (EPS), although rare, is a severe and often devastating complication that significantly impacts patient morbidity and mortality. Despite its low incidence, EPS underscores the importance of careful monitoring and management of long-term PD patients. Additional complications, including metabolic disturbances, pancreatitis, and hemoperitoneum, further complicate care. Looking ahead, improving catheter management, preserving peritoneal membrane function, and exploring new dialysis solutions are essential to reducing these complications and optimizing outcomes for pediatric patients on PD.

Bioimpedance Analysis in CKD and HF Patients: A Critical Review of Benefits, Limitations, and Future Directions

Bioimpedance analysis (BIA) is a validated non-invasive technique already proven to be useful for the diagnosis, prognosis, and management of body fluids in subjects with heart failure (HF) and chronic kidney disease (CKD). Although BIA has been widely employed for research purposes, its clinical application is still not fully widespread. The aim of this review is to provide a comprehensive overview of the state of the art of BIA utilization by analyzing the clinical benefits, limitations, and potential future developments in this clinically unexplored field.

Diastolic function in chronic kidney disease

Chronic kidney disease (CKD) is characterized by clustered age-independent concentric left ventricular (LV) geometry, geometry-independent systolic dysfunction and age and heart rate-independent diastolic dysfunction. Concentric LV geometry is always associated with echocardiographic markers of abnormal LV relaxation and increased myocardial stiffness, two hallmarks of diastolic dysfunction. Non-haemodynamic mechanisms such as metabolic and electrolyte abnormalities, activation of biological pathways and chronic exposure to cytokine cascade and the myocardial macrophage system also impact myocardial structure and impair the architecture of the myocardial scaffold, producing and increasing reactive fibrosis and altering myocardial distensibility. This review addresses the pathophysiology of diastole in CKD and its relations with cardiac mechanics, haemodynamic loading, structural conditions, non-haemodynamic factors and metabolic characteristics. The three mechanisms of diastole will be examined: elastic recoil, active relaxation and passive distensibility and filling. Based on current evidence, we briefly provide methods for quantification of diastolic function and discuss whether diastolic dysfunction represents a distinct characteristic in CKD or a proxy of the severity of the cardiovascular condition, with the potential to be predicted by the general cardiovascular phenotype. Finally, the review discusses assessment of diastolic function in the context of CKD, with special emphasis on end-stage kidney disease, to indicate whether and when in-depth measurements might be helpful for clinical decision making in this context.

Impedance-based remote monitoring in patients with heart failure and concomitant chronic kidney disease

AIMS

Remote monitoring (RM) of thoracic impedance represents an early marker of pulmonary congestion in heart failure (HF). Chronic kidney disease (CKD) may promote fluid overload in HF patients. We investigated whether concomitant CKD affected the efficacy of impedance-based RM in the OptiLink HF trial.

METHODS AND RESULTS

Among HF patients included in the OptiLink HF trial, time to the first cardiovascular hospitalization and all-cause death according to the presence of concomitant CKD was analysed. CKD was defined as GFR < 60 mL/min/1.73 m2 at enrolment. Of the 1002 patients included in OptiLink HF, 326 patients (33%) had HF with concomitant CKD. The presence of CKD increased transmission of telemedical alerts (median of 2 (1-5) vs. 1 (0-3); P = 0.012). Appropriate contacting after alert transmission was equally low in patients with and without CKD (57% vs. 59%, P = 0.593). The risk of the primary endpoint was higher in patients with CKD compared with patients without CKD (hazard ratio (HR), 1.62 [95% confidence interval (CI), 1.16-2.28]; P = 0.005). Impedance-based RM independently reduced primary events in HF patients with preserved renal function, but not in those with CKD (HR 0.68 [95% CI, 0.52-0.89]; P = 0.006).

CONCLUSIONS

The presence of CKD in HF patients led to a higher number of telemedical alert transmissions and increased the risk of the primary endpoint. Inappropriate handling of alert transmission was commonly observed in patients with chronic HF and CKD. Guidance of HF management by impedance-based RM significantly decreased primary event rates in patients without CKD, but not in patients with CKD.

Incidence of hospital admissions in bioimpedance-guided fluid management among maintenance hemodialysis patients-Results of a randomized controlled trial

INTRODUCTION

Hemodialysis is life-sustaining in kidney failure. However, proper regulation of body fluids depends on an accurate estimate of target weight. This trial aims to compare clinical endpoints between target weight estimation guided by bioimpedance spectroscopy and usual care in hemodialysis patients.

METHODS

This is an open-label, parallel-group, controlled trial that randomized, through a table of random numbers, adult patients on maintenance hemodialysis to target weight estimation based on monthly clinical evaluation alone or added to evaluation by bioimpedance twice a year. The primary outcome was survival, and the secondary outcomes were the rate of hospital admissions, change in blood pressure (BP), and antihypertensive drugs load. Participants were followed for 2 years. Survival analysis was performed using Kaplan-Meier estimator and Log-rank test, and hospital admissions were analyzed by the incidence-rate ratio.

FINDINGS

One hundred and ten patients were randomized to the usual care (52) or bioimpedance (58) groups, with a mean age of 57.4 (15.4) years, 64 (58%) males. There was no difference between the groups at baseline. Survival was not significantly different between groups (log-rank test p = 0.68), but the trial was underpowered for this outcome. There was also no difference between the groups in the change in systolic or diastolic BP or in the number of antihypertensive drugs being used. The incidence rate of hospital admissions was 3.1 and 2.1 per person-year in usual care and bioimpedance groups, respectively, with a time-adjusted incidence rate ratio of 1.48 (95% CI: 1.20-1.82, p = 0.0001) and attributable fraction of risk among exposed individuals of 0.32 (95% CI: 0.17-0.45).

DISCUSSION

The inclusion of bioimpedance data to guide the estimation of target weight in hemodialysis patients had no detectable impact on survival or BP control, but significantly reduced the incidence rate of hospital admissions. The study was registered at ClinicalTrials.gov Identifier: NCT05272800.

Artificial Intelligence-Based Echocardiographic Left Atrial Volume Measurement with Pulmonary Vein Comparison

This paper combines echocardiographic signal processing and artificial intelligence technology to propose a deep neural network model adapted to echocardiographic signals to achieve left atrial volume measurement and automatic assessment of pulmonary veins efficiently and quickly. Based on the echocardiographic signal generation mechanism and detection method, an experimental scheme for the echocardiographic signal acquisition was designed. The echocardiographic signal data of healthy subjects were measured in four different experimental states, and a database of left atrial volume measurements and pulmonary veins was constructed. Combining the correspondence between ECG signals and echocardiographic signals in the time domain, a series of preprocessing such as denoising, feature point localization, and segmentation of the cardiac cycle was realized by wavelet transform and threshold method to complete the data collection. This paper proposes a comparative model based on artificial intelligence, adapts to the characteristics of one-dimensional time-series echocardiographic signals, automatically extracts the deep features of echocardiographic signals, effectively reduces the subjective influence of manual feature selection, and realizes the automatic classification and evaluation of human left atrial volume measurement and pulmonary veins under different states. The experimental results show that the proposed BP neural network model has good adaptability and classification performance in the tasks of LV volume measurement and pulmonary vein automatic classification evaluation and achieves an average test accuracy of over 96.58%. The average root-mean-square error percentage of signal compression is only 0.65% by extracting the coding features of the original echocardiographic signal through the convolutional autoencoder, which completes the signal compression with low loss. Comparing the training time and classification accuracy of the LSTM network with the original signal and encoded features, the experimental results show that the AI model can greatly reduce the model training time cost and achieve an average accuracy of 97.97% in the test set and increase the real-time performance of the left atrial volume measurement and pulmonary vein evaluation as well as the security of the data transmission process, which is very important for the comparison of left atrial volume measurement and pulmonary vein. It is of great practical importance to compare left atrial volume measurements with pulmonary veins.