Left atrial strain is associated with adverse cardiovascular events in patients with end-stage renal disease: Findings from the Cardiac, Endothelial Function and Arterial Stiffness in ESRD (CERES) study

Left atrial strain in patients after arterial switch operation for transposition of the great arteries

BACKGROUND

Left atrial (LA) strain, comprising LA reservoir, conduit and contractile function could add mechanistic information of patients after arterial switch operation (ASO) for transposition of the great arteries (TGA). ASO patients might have abnormal ventriculoarterial coupling, which makes them vulnerable to left ventricle (LV) dysfunction and results in reduced exercise capacity. This explorative study aimed to evaluate the relation between LA strain, atrial size, ventricular function, and exercise data obtained by cardiopulmonary exercise testing (CPET).

METHODS

In a cohort of 44 patients (71% male, mean age 25 ± 4 years) LA strain was measured using transthoracic speckle-tracking echocardiography. Further assessment involved standard echocardiography, CPET evaluation, and blood sampling. LA strain values were compared to normal values. Correlations were calculated. Regression analysis with all strain variables to the CPET data was performed.

RESULTS

LA reservoir, conduit and contractile strain were normal in 30%, 89% and 50% of the patients, respectively. LA reservoir/contractile strain correlated to LV ejection fraction (ρ 0.310/-0.159, respectively) and LA reservoir/conduit strain correlated to the LA volume index (ρ 0.336/-0.357, respectively). None of the individual LA strain parameters were associated with the CPET variables. In multivariate regression analysis, LA contractile strain was significantly associated with the percentage of predicted maximal heart rate (β - 2.555).

CONCLUSIONS

These data suggest that in TGA patients after ASO repair LA strain is impaired and correlates with LA size and LV function. However, impaired LA strain wasn't associated with the standard CPET parameters. As such, clinical significance needs to be further unravelled.

Evaluation of a large-scale aptamer proteomics platform among patients with kidney failure on dialysis

BACKGROUND

Patients with kidney failure suffer high mortality, and we currently lack markers for risk stratification for these patients. We carried out a quality control study of a modified aptamer assay (SomaScan v.4.0) that measures ~ 5000 proteins, in preparation for a larger study using this platform in cohorts with kidney failure.

METHODS

Forty participants from the Cardiac, Endothelial Function and Arterial Stiffness in End-Stage Renal Disease (CERES study) were selected to analyze technical and short-term biological variability, orthogonal correlations and differential protein expression in plasma from patients who died during 2.5 year follow-up. Long-term (one year) variability was studied in 421 participants in the Chronic Renal Insufficiency Cohort. We evaluated 4849 aptamers (4607 unique proteins) using data formats including raw data and data formatted using Adaptive Normalization by Maximum Likelihood (ANML), an algorithm developed for SomaScan data in individuals with normal kidney function.

RESULTS

In ANML format, median[IQR] intra-assay coefficient of variation (CV) was 2.38%[1.76, 3.40] and inter-assay CV was 7.38%[4.61, 13.12]. Short-term within-subject CV was 5.76% [3.35, 9.72]; long-term CV was 8.71%[5.91, 13.37]. Spearman correlations between aptamer and traditional assays for PTH, NT-proBNP, FGF-23 and CRP were all > 0.7. Fold-change (FC) in protein levels among non-survivors, significant after Bonferroni correction, included SVEP1 (FC[95% CI] 2.14 [1.62, 2.82]), keratocan (1.74 [1.40, 2.15]) and LanC-like protein 1 (0.56 [0.45, 0.70]). Compared to raw aptamer data, technical and short-term biological variability in paired samples was lower in ANML-formatted data. ANML formatting had minimal impact on orthogonal correlations with traditional assays or the associations of proteins with the phenotype of mortality.

CONCLUSIONS

SomaScan had excellent technical variability and low within-subject short-term variability. ANML formatting could facilitate comparison of biomarker results with other studies that utilize this format. We expect SomaScan to provide novel and reproducible information in patients with kidney failure on dialysis.

Cardiac Imaging Biomarkers in Chronic Kidney Disease

Uremic cardiomyopathy (UC), the peculiar cardiac remodeling secondary to the systemic effects of renal dysfunction, is characterized by left ventricular (LV) diffuse fibrosis with hypertrophy (LVH) and stiffness and the development of heart failure and increased rates of cardiovascular mortality. Several imaging modalities can be used to obtain a non-invasive assessment of UC by different imaging biomarkers, which is the focus of the present review. Echocardiography has been largely employed in recent decades, especially for the determination of LVH by 2-dimensional imaging and diastolic dysfunction by pulsed-wave and tissue Doppler, where it retains a robust prognostic value; more recent techniques include parametric assessment of cardiac deformation by speckle tracking echocardiography and the use of 3D-imaging. Cardiac magnetic resonance (CMR) imaging allows a more accurate assessment of cardiac dimensions, including the right heart, and deformation by feature-tracking imaging; however, the most evident added value of CMR remains tissue characterization. T1 mapping demonstrated diffuse fibrosis in CKD patients, increasing with the worsening of renal disease and evident even in early stages of the disease, with few, but emerging, prognostic data. Some studies using T2 mapping highlighted the presence of subtle, diffuse myocardial edema. Finally, computed tomography, though rarely used to specifically assess UC, might provide incidental findings carrying prognostic relevance, including information on cardiac and vascular calcification. In summary, non-invasive cardiovascular imaging provides a wealth of imaging biomarkers for the characterization and risk-stratification of UC; integrating results from different imaging techniques can aid a better understanding of the physiopathology of UC and improve the clinical management of patients with CKD.

Effects and Clinical Value of Peritoneal Dialysis on Water and Water Balance, Adverse Reactions, Quality of Life, and Clinical Prognosis in Patients with Decompensated Chronic Nephropathy: A Systematic Review and Meta-Analysis

Objective

To systematically evaluate the effects of peritoneal dialysis and hemodialysis on renal function and quality of life in patients with end-stage renal disease. An evidence-based medical rationale would be provided for peritoneal dialysis or hemodialysis treatment in patients with end-stage renal disease.

Methods

The PubMed, EMBASE, ScienceDirect, Cochrane Library, China National Knowledge Infrastructure (CNKI), China VIP Database, Wanfang, and China Biomedical Literature Database (CBM) online databases were searched. Comparisons on the effects of peritoneal dialysis on renal function and quality of life were taken between patients with end-stage renal disease (RD). The data were extracted independently by two researchers. The bias-risk-included literatures were assessed according to the Cochrane manual 5.1.0 standard. RevMan 5.4 statistical software was used to analyze the collected data via meta-analysis.

Results

Seven RCT articles were finally included. A total of 745 samples were analyzed via meta-analysis. The obvious heterogeneities of serum creatinine (Scr) and blood urea nitrogen (BUN) were discovered (P < 0.00001) in the selective investigations. According to the results of this analysis, it was indicated that the renal function of patients with end-stage renal disease treated by peritoneal dialysis was significantly better than that of hemodialysis. According to the meta-analysis, there was obvious heterogeneity of life quality among the included research data. It was indicated that the score of quality of life of patients with end-stage renal disease treated by peritoneal dialysis was significantly better than that of hemodialysis.

Conclusion

Compared with hemodialysis in the treatment of end-stage renal disease, the renal function and quality of life of patients with peritoneal dialysis are better than those of hemodialysis. More further studies and follow-up with higher methodological quality and longer intervention time are still needed for further verification.