Role of the gut microbiota and their metabolites in hemodialysis patients.

High serum phosphate levels in chronic kidney disease (CKD) are linked to adverse health outcomes, including cardiovascular disease, kidney disease progression, and all-cause mortality. This study is aimed to find out which microorganisms or microbial functions have a significant impact on higher calcium-phosphorus product (Ca x P) after they undergo hemodialysis (HD) treatment. Feces samples from 30 healthy controls, 15 dialysis patients with controlled Ca xP (HD), and 16 dialysis patients with higher Ca xP (HDHCP) were collected to perform in 16S amplicon sequencing. We found gut microbial composition was significantly different between hemodialysis patients and healthy controls. Three phyla including Firmicutes, Actinobacteria, and Proteobacteria were significantly enriched in hemodialysis patients. Although only one genus, Lachnospiraceae_FCS020_group, was significantly increased in higher Ca xP group, there were four metabolic pathways predicted by PICRUSt significantly increased in higher Ca xP group and associated with causing VC, including the pentose phosphate pathway, steroid biosynthesis, terpenoid backbone biosynthesis, and fatty acid elongation pathway. Characterizing dysbiosis of gut microbiome played the important role in hemodialysis patients.

Predicting ventricular tachyarrhythmia in patients with systolic heart failure based on texture features of the gray zone from contrast-enhanced magnetic resonance imaging.

BACKGROUND: Previous research showed that gray zone detected by late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging could help identify high-risk patients. In this study, we investigated whether LGE-CMR gray zone heterogeneity measured by image texture features could predict cardiovascular events in patients with heart failure (HF). METHOD: This is a retrospective cohort study. Patients with systolic HF undergoing CMR imaging were enrolled. Cine and LGE images were analyzed to derive left ventricular (LV) function and scar characteristics. Entropy and uniformity of gray zones were derived by texture analysis. RESULTS: A total of 82 systolic HF patients were enrolled. After a median 1021 (25%-75% quartiles, 205-2066) days of follow-up, the entropy (0.60 ± 0.260 vs. 0.87 ± 0.28, p = 0.013) was significantly increased while the uniformity (0.68 ± 0.14 vs. 0.53±0.15, p = 0.016) was significantly decreased in patients with ventricular tachycardia or ventricular fibrillation (VT/VF). The percentage of core scar (21.9 ± 10.6 vs. 30.6 ± 10.4, p = 0.029) was higher in cardiac mortality group than survival group while the uniformity (0.55 ± 0.17 vs. 0.67 ± 0.14, p = 0.018) was lower in cardiac mortality group than survival group. A multivariate Cox regression model showed that higher percentage of gray zone area (HR = 8.805, 1.620-47.84, p = 0.045), higher entropy (>0.85) (HR = 1.391, 1.092-1.772, p = 0.024) and lower uniformity (≦0.54) (HR = 0.535, 0.340-0.842, p = 0.022) were associated with VT/VF attacks. Also, higher percentage of gray zone area (HR = 5.716, 1.379-23.68, p = 0.017), core scar zone (HR = 1.939, 1.056-3.561, p = 0.025), entropy (>0.85) (HR = 1.434, 1.076-1.911, p = 0.008) and lower uniformity (≦0.54) (HR = 0.513, 0.296-0.888, p = 0.009) were associated with cardiac mortality during follow-up. CONCLUSIONS: Gray zone heterogeneity by texture analysis method could provide additional prognostic value to traditional LGE-CMR substrate analysis method.

Noninvasive Hemodynamic Profiles during Hemodialysis in Patients with and without Heart Failure.

BACKGROUND: Although the dynamics of blood pressure (BP) during dialysis provide information related to the control system, the prognosis and relationships between temporal changes in intradialytic hemodynamic regulation, BP, and decreased cardiac function remain largely unclear. METHODS: Hemodynamic parameters, including heart rate (HR), stroke volume (SV), cardiac index, and systemic vascular resistance index, were recorded using a noninvasive hemodynamic device on a beat-by-beat basis in 40 patients on dialysis who were divided into three groups, i.e., those with and without BP lability and those with heart failure (HF). Statistical measurements, including mean, standard deviation, coefficient of variation (CV), and index of nonrandomness of each hemodynamic parameter were derived from the three different phases divided equally during dialysis and compared using 3×3 two-way mixed-model analysis of variance to determine the effects of the different stages of hemodialysis (HD), cardiac function, and intradialytic changes in BP on the hemodynamic parameters. In addition, multivariate Cox regression was performed to determine the association between the changes in the derived parameters and BP lability. RESULTS: The average SV tended to decrease during HD in all groups (p = 0.041). A significant decrease was observed in the CV of SV between the first two stages of HD in patients with labile BP and HF when compared to those without labile BP (p = 0.037). Significant interactions between group and stage of the index of nonrandomness for HR were also noted; this index was significantly higher in patients without labile BP than in those with labile BP or HF (p = 0.048). A higher difference between the early and middle stages of HD for nonrandomness indexes of HR was an independent predictor of reduced BP lability during HD (HR = 0.844, 95% confidence interval 0.722-0.987, p = 0.034). CONCLUSIONS: Increases in the CV of SV and the index of nonrandomness for HR during early-stage HD in response to decreased SV may be associated with better BP control during HD. This finding suggests that patients with more structurally meaningful hemodynamic control have a more favorable cardiovascular outcome.

Alteration autonomic control of cardiac function during hemodialysis predict cardiovascular outcomes in end stage renal disease patients.

Dialysis-induced hemodynamic instability has been associated with increased risk of cardiovascular (CV) mortality. However, the control mechanisms beneath the dynamic BP changes and cardiac function during hemodialysis and subsequent CV events are not known. We hypothesize that the impaired hemodynamic control can be prognostic indicators for subsequent CV events in end stage renal diseaes (ESRD) patients. To explore the association of hemodynamic parameters and CV events in hemodialysis patients, we enrolled ESRD patients who received chronic hemodialysis without documented atherosclerotic cardiovascular disease and hemodynamic parameters were continuously obtained from the impedance cardiography during hemodialysis. A total of 35 patients were enrolled. 16 patients developed hospitalized CV events. The statistical properties [coefficient of variance (standard deviation / mean value; CoV)] of hourly beat-to-beat dynamics of hemodynamic parameters were calculated. The CoV of stroke volume (SV) and cardiac index (CI) between the 1st and 2nd hour of dialysis were significantly increased in patients without CV events compared to those with CV events. Higher CoV of SVdiff and CIdiff were significantly correlated with longer CV event-free survival, and the area under the receiver operating characteristic (ROC) curve showed fair overall discriminative power (0.783 and 0.796, respectively). The responses of hemodynamic control mechanisms can be independent predictive indexes for lower hospitalized CV events, which implies that these patients who have better autonomic control systems may have better CV outcomes.

Icodextrin dialysate improves nutritional and inflammatory profiles in peritoneal dialysis patients.

BACKGROUND: Previous studies demonstrate that icodextrin is superior to 4.25% dextrose for fluid removal in patients with high and high-average transport membrane. Recent studies reveal that controlling volume status improves malnutrition in peritoneal dialysis (PD) patients. This study hypothesized that icodextrin enhances nutritional and inflammatory status by improving fluid balance. METHODS: This retrospective case-control study investigated the effects of icodextrin on patient nutritional profiles over a one-year period. Thirty-two patients who used icodextrin for more than one year were classified as the "icodextrin group." Ten patients who used glucose-containing dialysate without icodextrin were classified as the control group. Clinical and laboratory parameters were compared between groups. Demographic and laboratory parameters were analyzed at baseline, 3 months, 6 months, and 12 months after starting icodextrin dialysis. RESULTS: Ultrafiltration of icodextrin per exchange in the icodextrin group was 66% higher than that for 4.25% dextrose exchange in the icodextrin group (icodextrin vs. 4.25% dextrose: 492.1 +/- 204.5 vs. 296.1 +/- 115.3 mL/exchange; p < 0.0001, paired t-test). The increased albumin and normalized protein catabolic rate (nPCR) after icodextrin for one year was unique for the icodextrin group (p < 0.0001 and p < 0.0001, respectively). The inflammatory marker high sensitivity C-reactive protein (hsCRP) decreased significantly only in the icodextrin group (p = 0.0048). CONCLUSION: Icodextrin dialysate may improve nutritional and inflammatory status in PD patients. However, the long-term clinical effects of icodextrin require further study.