Risk Factors and Outcomes Associated With Heart Failure With Preserved and Reduced Ejection Fraction in People With Chronic Kidney Disease.

BACKGROUND: Heart failure (HF) is associated with poor outcomes in people with chronic kidney disease, yet it is unknown whether outcomes differ by HF subtype. This study aimed to examine associations of incident HF with preserved ejection fraction (HFpEF) versus HF with reduced ejection fraction (HFrEF) with progression to end-stage kidney disease (ESKD) and mortality. METHODS: We studied individuals with chronic kidney disease in the CRIC study (Chronic Renal Insufficiency Cohort) who were free of HF at cohort entry. Incident HF hospitalizations were adjudicated and classified into HFpEF (ejection fraction, ≥50%) or HFrEF (ejection fraction, <50%) based on echocardiograms performed during the hospitalization or at a research study visit. ESKD was defined as need for chronic dialysis or kidney transplant. Cox proportional hazards were used to evaluate the association of time-updated HF subtype with risk of ESKD and mortality, adjusting for demographics, comorbidities, and medication use. RESULTS: Among the 3557 study participants without HF at cohort entry, mean age was 57 years and mean estimated glomerular filtration rate was 45 mL/min per 1.73 m2. A total of 682 participants had incident HF. Incidence rates for HFpEF and HFrEF were 0.9 (95% CI, 0.8-1.0) and 0.7 (95% CI, 0.6-0.8) per 100 person-years, respectively (Pdifference=0.005). Associations of incident HF with progression to ESKD were not statistically different for HFpEF (hazard ratio, 2.06 [95% CI, 1.66-2.56]) and HFrEF (hazard ratio, 1.80 [95% CI, 1.36-2.38]; P=0.42). The associations with mortality were stronger for HFrEF (hazard ratio, 2.73 [95% CI, 2.24-3.33]) compared with HFpEF (hazard ratio, 1.99 [95% CI, 1.65-2.40]; P=0.0002). CONCLUSIONS: In a chronic kidney disease population, the rates of HFpEF hospitalizations were greater than that of HFrEF. Risk of ESKD was high but not statically different across HF subtypes. There was a stronger association of HFrEF with mortality. Prevention and treatment of both HFpEF and HFrEF should be central priorities to improve outcomes in chronic kidney disease.

Exploring the nexus between fatigue, body composition, and muscle strength in hemodialysis patients.

BACKGROUND: Fatigue is a relatively prevalent condition among hemodialysis patients, resulting in diminished health-related quality of life and decreased survival rates. The purpose of this study was to investigate the relationship between fatigue and body composition in hemodialysis patients. METHODS: This cross-sectional study included 92 patients in total. Fatigue was measured by Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F) (cut-off ≤ 34). Body composition was measured based on quantitative computed tomography (QCT), parameters including skeletal muscle index (SMI), intermuscular adipose tissue (IMAT), and bone mineral density (BMD). Handgrip strength was also collected. To explore the relationship between fatigue and body composition parameters, we conducted correlation analyses and binary logistic regression. RESULTS: The prevalence of fatigue was 37% (n = 34), abnormal bone density was 43.4% (n = 40). There was a positive correlation between handgrip strength and FACIT-F score (r = 0.448, p < 0.001). Age (r = - 0.411, p < 0.001), IMAT % (r = - 0.424, p < 0.001), negatively associated with FACIT-F score. Multivariate logistic regression analysis shows that older age, lower serum phosphorus, higher IMAT% are associated with a high risk of fatigue. CONCLUSION: The significantly increased incidence and degree of fatigue in hemodialysis patients is associated with more intermuscular adipose tissue in paraspinal muscle.

Characterization of heart rate variability in end-stage renal disease patients after kidney transplantation with recurrence quantification analysis.

Heart rate variability (HRV) is a noninvasive approach to studying the autonomic modulation of heart rate in experimental settings, such as active standing sympathetic stimulation. It is known that patients with end-stage renal disease during active standing have few changes in HRV dynamics, which are improved after hemodialysis. However, it is unknown whether the response to active standing is recovered after definitive treatment with kidney transplantation. This work aims to assess the change in HRV dynamics in the supine position and active standing through time and frequency-based metrics, as well as recurrence plot quantitative analysis (RQA). We studied HRV dynamics by obtaining 5-minute electrocardiographic recordings from kidney transplant recipients who underwent an active standing test. The mean duration of heartbeats and their standard deviation diminished in active standing, compared with the supine position. Also, the low-frequency component of HRV and the presence of diagonal and vertical structures in RQA were predominant. A larger estimated glomerular filtration rate was significantly correlated with broader HRV in the supine position and during active standing. The narrower HRV during active standing may indicate a sympathetic response to external stimuli, which is expected in a functional cardiovascular system, and may be influenced by renal function.

A hierarchical kidney outcome using win statistics in patients with heart failure from the DAPA-HF and DELIVER trials.

Win statistics offer a new approach to the analysis of outcomes in clinical trials, allowing the combination of time-to-event and longitudinal measurements and taking into account the clinical importance of the components of composite outcomes, as well as their relative timing. We examined this approach in a post hoc analysis of two trials that compared dapagliflozin to placebo in patients with heart failure and reduced ejection fraction (DAPA-HF) and mildly reduced or preserved ejection fraction (DELIVER). The effect of dapagliflozin on a hierarchical composite kidney outcome was assessed, including the following: (1) all-cause mortality; (2) end-stage kidney disease; (3) a decline in estimated glomerular filtration rate (eGFR) of ≥57%; (4) a decline in eGFR of ≥50%; (5) a decline in eGFR of ≥40%; and (6) participant-level eGFR slope. For this outcome, the win ratio was 1.10 (95% confidence interval (CI) = 1.06-1.15) in the combined dataset, 1.08 (95% CI = 1.01-1.16) in the DAPA-HF trial and 1.12 (95% CI = 1.05-1.18) in the DELIVER trial; that is, dapagliflozin was superior to placebo in both trials. The benefits of treatment were consistent in participants with and without baseline kidney disease, and with and without type 2 diabetes. In heart failure trials, win statistics may provide the statistical power to evaluate the effect of treatments on kidney as well as cardiovascular outcomes.

Temporal changes in toe-brachial index results in haemodialysis patients.

INTRODUCTION: Toe brachial index (TBI), the ratio of toe pressure to systolic blood pressure (SBP), helps predict peripheral arterial disease. In patients with kidney failure this may be performed during haemodialysis for convenience. Until recently there has been little evaluation of the impact of haemodialysis in limb and systemic perfusion on these values. We aimed to determine if the values of TBI would change during and after dialysis compared to pre-dialysis assessments. METHODS: Using a repeated measures study, TBIs and toe pressures were measured using the Hadeco Smartop Vascular Ultrasound Doppler in 31 patients undergoing haemodialysis. TBI assessments were completed pre-dialysis and compared to values obtained at 1 hour, 2 hours, 3 hours, and post-dialysis to monitor change in TBI results. Comparison of values for each patient were tested for differences using paired t-tests. Linear mixed-effects models were used to test for the effect of patient and clinical factors on change in outcome measures. RESULTS: Mean TBI decreased from pre-dialysis at 1 hour (0.72 to 0.63, p = 0.01) and remained lower at 2 hours and 3 hours, before returning to pre-dialysis levels at post-dialysis. Mean systolic blood pressure also declined during dialysis. Mean TBI results were lower in those with a history of lower limb ulceration and in females. Sixteen patients (51.6%) had a normal TBI at baseline, 14 (45.2%) had a mildly low TBI, and one (3.2%) had a severely low TBI. Between baseline and 1 h, five patient's results moved from normal to mildly abnormal and one from mildly abnormal to severely abnormal. As haemodialysis concluded (post-dialysis) there were 17 (56.7%) 'normal' TBIs, with no severely abnormal TBIs (p = 0.73). 0.30). CONCLUSION: TBI and toe pressures are impacted significantly by dialysis. TBI and toe pressure assessments should be conducted before haemodialysis begins, or between dialysis sessions to avoid variability.

Bioelectrical Impedance Phase Angle Value and Prolongations of PR and Corrected QT Intervals in Patients Undergoing Dialysis.

INTRODUCTION: Phase angle value, derived from bioelectrical impedance analysis, represents the body cell mass and nutritional status of patients undergoing hemodialysis. Although the phase angle value has clinical significance in these patients, its relationship with electrocardiogram (ECG), another clinically relevant bioelectrical examination, has not yet been well clarified. METHODS: Two hundred and twenty-four patients undergoing dialysis (80 females and 144 males; mean ± SD, 72.2 ± 12.0 years old; 117 diabetic and 107 nondiabetic patients) were studied retrospectively. Multifrequency bioelectrical impedance analysis was performed immediately after the end of dialysis therapy. The phase shift was geometrically converted into a phase angle value. The ECG was recorded simultaneously, and the upper limits of the PR interval, QRS width, and corrected QT interval (QTc) were set at 0.20, 0.12, and 0.44 s, respectively. The geriatric nutritional risk index (GNRI), a representative nutritional index, was also determined. In addition, we examined the incidence of cardiac events, including heart failure, myocardial infarction, cardiac revascularization procedure, cardiac arrhythmia, and cardiac death, or all-cause death. RESULTS: Of 224 patients undergoing dialysis, the prolongation of the PR interval, QRS width, and QTc was found in 30.7, 17.4, and 62.1%, respectively. The prevalence of QTc prolongation was higher in females and diabetic patients than in males and nondiabetic patients. An inverse relationship between phase angle value and QTc was observed only in males and nondiabetic patients. The relationships of GNRI both with phase angle value and QTc were stronger in males and nondiabetic patients. In addition, PR interval was inversely correlated with a phase angle value only in nondiabetic patients. No significant correlation was found between phase angle value and QRS width. Five-year survival probability for the composite endpoints was significantly worse in patients with lower phase angle values. QTc prolongation was associated with survival in males and nondiabetic patients. Prolonged PR was associated with survival in nondiabetic patients. DISCUSSION: Relationships between phase angle value and ECG findings were demonstrated in patients undergoing dialysis, especially in males and nondiabetic patients. Although the phase angle value has been considered as an index for evaluating nutritional status, another clinical application of phase angle value in predicting cardiac complications seems to be useful.

The impact of malnutrition on the effectiveness of intradialytic exercise in hemodialysis patients: amulticenter cohort study.

PURPOSE: Low physical function can be effectively improved via intradialytic exercise. However, the association between the effects of intradialytic exercise on physical function and malnutrition severity has not been studied extensively. This study aimed to investigate the impact of nutritional status severity on physical function in patients undergoing hemodialysis with low physical function to whom intradialytic exercise was prescribed. METHODS: The participants were patients with decreased mobility [walking speed < 1.0 m/s and/or Short Physical Performance Battery (SPPB) < 12] who had been undergoing hemodialysis thrice a week for 6 months and performing intradialytic exercise program. Patients were divided into groups based on the Geriatric Nutritional Risk Index (GNRI) [Non-malnutrition group (GNRI > 98), Gentle/slim malnutrition group (GNRI ≤ 98, GNRI ≥ 92), Mild malnutrition group (GNRI < 92, GNRI ≥ 82), Severe malnutrition group (GNRI < 82)]. The primary outcomes were Grip strength, isometric knee extension strength (IKES), SPPB, and 10-m walking speed measured at baseline and at 6 months. Statistical analyses were performed using a linear mixed-effects model with the intention-to-treat analysis, including within-group analysis and between-group comparison. RESULTS: A total of 805 participants were included in the study. Within-group comparisons showed significantly improved IKES, 10-m walking speed, and SPPB improved, except in the Severe malnutrition group. Grip strength significantly improved in the Gentle/slim and mild malnutrition groups. Between-group comparison with controls showed that the improvement in Grip strength was significantly bigger in the Gentle/slim malnutrition group [0.98 (0.15 to 1.82) kg] than in the non-malnutrition group. However, IKES in the Severe malnutrition group [- 5.14 (- 9.18 to - 1.10) %] less significantly improve than that in the non-malnutrition group. No significant differences were found in the other indices. CONCLUSION: In patients with severe malnutrition, the changes in IKES scores resulting from Intradialytic exercise were significantly smaller than those observed in non-malnourished patients. Therefore, it is necessary to initiate suitable nutritional and exercise therapy based on the severity of malnutrition.

Individual versus integration of multiple components of central blood pressure and aortic stiffness in predicting cardiovascular mortality in end-stage renal diseases.

Aortic stiffness, measured by carotid-femoral pulse wave velocity (PWV), is a predictor of cardiovascular (CV) mortality in patients with end-stage renal disease (ESRD). Aortic stiffness increases aortic systolic and pulse pressures (cSBP, cPP) and augmentation index adjusted for a heart rate of 75 beats per minute (AIx@75). In this study, we examined if the integration of multiple components of central blood pressure and aortic stiffness (ICPS) into risk score categories could improve CV mortality prediction in ESRD. In a prospective cohort of 311 patients with ESRD on dialysis who underwent vascular assessment at baseline, 118 CV deaths occurred after a median follow-up of 3.1 years. The relationship between hemodynamic parameters and CV mortality was analyzed through Kaplan-Meier and Cox survival analysis. ICPS risk score from 0 to 5 points were calculated from points given to tertiles, and were regrouped into three risk categories (Average, High, Very-High). A strong association was found between the ICPS risk categories and CV mortality (High risk HR = 2.20, 95% CI: 1.05-4.62, P = 0.036); Very-High risk (HR = 4.44, 95% CI: 2.21-8.92, P < 0.001) as compared to the Average risk group. The Very-High risk category remained associated with CV mortality (HR = 3.55, 95% CI: 1.37-9.21, P = 0.009) after adjustment for traditional CV risk factors as compared to the Average risk group. While higher C-statistics value of ICPS categories (C: 0.627, 95% CI: 0.578-0.676, P = 0.001) was not statistically superior to PWV, cPP or AIx@75, the use of ICPS categories resulted in a continuous net reclassification index of 0.56 (95% CI: 0.07-0.99). In conclusion, integration of multiple components of central blood pressure and aortic stiffness may potentially be useful for better prediction of CV mortality in this cohort.

Race-Based Equations Delayed Black Patients From Getting Onto Kidney Transplant Lists-An Unprecedented New Policy Seeks to Undo the Damage.

This Medical News article is an interview about new policy from the US Organ Procurement and Transplantation Network to address the harms of race-based kidney function estimation.

Association of a low ankle brachial index with progression to end-stage kidney disease in patients with advanced-stage diabetic kidney disease.

INTRODUCTIONS: The effect of a low ankle-brachial index (ABI) in patients with advanced-stage diabetic kidney disease is not fully understood. This study investigates the prevalence of a low ABI in patients with advanced-stage diabetic kidney disease, which was defined as a urinary albumin-to-creatinine ratio (UACR) ≥300 mg/g and an estimated glomerular filtration rate (eGFR) between 15-60 mL/min/1.73 m2. Furthermore, the association between a low ABI and end-stage kidney disease (ESKD) was determined. METHODS: This single-center, retrospective, cohort study included 529 patients with advanced-stage diabetic kidney disease who were stratified into groups according to the ABI: high (>1.3), normal (0.9-1.3), and low (<0.9). The Kaplan-Meier method and Cox proportional analysis were used to examine the association between the ABI and ESKD. RESULTS: A total of 42.5% of patients with a low ABI progressed to ESKD. A low ABI was associated with a greater risk of ESKD (hazard ratio (HR): 1.073). After adjusting for traditional chronic kidney disease risk factors, a low ABI remained associated with a greater risk of ESKD (HR: 1.758; 95% confidence interval: 1.243-2.487; p = 0.001). CONCLUSIONS: These results indicate that patients with a low ABI should be monitored carefully. Furthermore, preventive therapy should be considered to improve the long-term kidney survival of patients with residual kidney function.

Renoprotective Effect of Intraoperative Dexmedetomidine in Renal Transplantation.

BACKGROUND: Renal dysfunction after kidney transplantation may be influenced by many reasons. This study was designed to evaluate whether the administration of dexmedetomidine (Dex) could ameliorate renal function and prognosis after kidney transplantation. METHODS: A total of 65 patients were divided into Dex group (n = 33) and Con group (Con, n = 32). Dex group intravenously received an initial loading dose of 0.6 µg/kg Dex for 15 min before anaesthesia induction, followed by a rate of 0.4 µg/kg/h until 30 min after kidney reperfusion. By contrast, Con group received saline. The concentration of urinary kidney injury molecule-1 (KIM-1), serum creatinine (Cr), blood urea, urine output, ß2 microglobulin (ß2-MG), Cystatin C (CysC), and estimated glomerular filtration rate (eGFR) was recorded and compared between two groups during the course of the hospitalization or follow-up. Mean arterial pressure (MAP) and heart rate (HR), vasoactive drugs, and anaesthetics were recorded during the operation. Pain degree was evaluated using a visual analogue scale (VAS) after operation. Delayed graft function (DGF), graft loss, length of hospital stay, and mortality were compared between groups. RESULTS: The concentration of KIM-1 in Dex group was lower than Con group at 2 h (P = 0.018), 24 h (P = 0.013), 48 h (P < 0.01), and 72 h (P < 0.01) after reperfusion. MAP of Dex group after tracheal intubation (P = 0.012) and incision (P = 0.018) and HR after intubation (P = 0.021) were lower than that of Con group. The dosage of sufentanil during operation in Dex group was less than Con group (P = 0.039). Patients that used atropine in Dex group were more than Con group (P = 0.027). Patients who received Dex presented with lower VAS scores at 6 h (P = 0.01) and 12 h (P = 0.002) after operation. Concentration of serum Cr and blood urea had no significant differences between groups before operation and on postoperative day 1 to 6. Urine output was recorded for 6 days after operation and had no differences between groups. Also, no differences were identified between two groups in urea, Cr, ß2-MG, CysC, and eGFR in the first 3 months after operation. Incidence of DGF after operation was detected no difference between groups, while length of hospital stay in Dex group was less than Con group (P = 0.012). CONCLUSION: Dex can decrease kidney injury marker level, attenuate perioperative stress, relieve the dosage of sufentanil and postoperative pain, and reduce length of hospital stay. However, Dex is not associated with changes in prognosis in the first 3 months after transplantation.

Step length and fall risk in adults with chronic kidney disease: a pilot study.

BACKGROUND: Patients with chronic kidney disease commonly experience gait abnormalities, which predispose to falls and fall-related injuries. An unmet need is the development of improved methods for detecting patients at high risk of these complications, using tools that are feasible to implement in nephrology practice. Our prior work suggested step length could be such a marker. Here we explored the use of step length as a marker of gait impairment and fall risk in adults with chronic kidney disease. METHODS: We performed gait assessments in 2 prospective studies of 82 patients with stage 4 and 5 chronic kidney disease (n = 33) or end-stage renal disease (ESRD) (n = 49). Gait speed and step length were evaluated during the 4-m walk component of the Short Physical Performance Battery (SPPB). Falls within 6 months prior to or following enrollment were identified by questionnaire. Associations of low step length (≤47.2 cm) and slow gait speed (≤0.8 m/s) with falls were examined using logistic regression models adjusted for demographics and diabetes and peripheral vascular disease status. RESULTS: Assessments of step length were highly reproducible (r = 0.88, p < 0.001 for duplicate measurements at the same visit; r = 0.78, p < 0.001 between baseline and 3-month evaluations). Patients with low step length had poorer physical function, including lower SPPB scores, slower gait speed, and lower handgrip strength. Although step length and gait speed were highly correlated (r = 0.73, p < 0.001), one-third (n = 14/43) of patients with low step length did not have slow gait speed. Low step length and slow gait speed were each independently associated with the likelihood of falls (odds ratio (OR) 3.90 (95% confidence interval (CI) 1.05-14.60) and OR 4.25 (95% CI 1.24-14.58), respectively). Compared with patients who exhibited neither deficit, those with both had a 6.55 (95% CI 1.40-30.71) times higher likelihood of falls, and the number of deficits was associated with a graded association with falls (p trend = 0.02). Effect estimates were similar after further adjustment for ESRD status. CONCLUSIONS: Step length and gait speed may contribute additively to the assessment of fall risk in a general adult nephrology population.

Effects of Hemodialysis on Intraocular Pressure and Ocular Biological Parameters in Different Angle Structures.

PURPOSE: This study is aimed at evaluating the effects of hemodialysis on intraocular pressure (IOP) and exploring the possible factors affecting IOP. METHODS: Fifty-two patients with hemodialysis (HD) that were diagnosed with chronic renal failure by nephrology were divided into four groups: wide angle, narrow angle, extremely narrow angle, and closed angle. IOP, central anterior chamber depth (ACD), lens thickness (LT), angle opening distance (AOD), trabecular-iris angle (TIA), iris thickness (IT), and ciliary body thickness (CBT) were recorded before and after HD. The Pearson coefficient test was used to determine correlations among changes in IOP and AOD, ACD, TIA, IT, CBT, and LT. RESULTS: The IOP in the extremely narrow angle group had significant difference compared with that in the wide angle group and narrow angle group (P < 0.05, P < 0.01). In the narrow angle group, change in LT was positively correlated with change in IOP (P < 0.05). In the extremely narrow angle group, change in LT was positively correlated with change in IOP (P<0.01), whereas changes in AOD and TIA were negatively correlated with change in IOP (P < 0.01; P < 0.05). CONCLUSION: The effect of HD on IOP varies with the structure of the anterior chamber. The increasing of IOP in the extremely narrow-angle group is related with the changes of structure of anterior chamber.

Association of Intraindividual Difference in Estimated Glomerular Filtration Rate by Creatinine vs Cystatin C and End-stage Kidney Disease and Mortality.

Importance: As cystatin C is increasingly adopted to estimate glomerular filtration rate (eGFR), clinicians will encounter patients in whom cystatin C-based eGFR (eGFRcys) and creatinine-based eGFR (eGFRcr) differ widely. The clinical implications of these differences, eGFRdiffcys-cr, are unknown. Objective: To evaluate the associations of eGFRdiffcys-cr with end-stage kidney disease (ESKD) and mortality among individuals with chronic kidney disease (CKD). Design, Setting, and Participants: This is a prospective cohort study of 4956 individuals with mild to moderate CKD from 7 clinical centers in the United States who enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study between 2003 to 2018. Statistical analyses were completed in December 2021. Exposures: eGFRdiffcys-cr (eGFRcys - eGFRcr) was calculated at baseline and annually thereafter for 3 years. Because 15 mL/min/1.73 m2 represents a clinically meaningful difference in eGFR that also distinguishes CKD stages, eGFRdiffcys-cr was categorized as: less than -15 mL/min/1.73 m2, -15 to 15 mL/min/1.73 m2, and 15 mL/min/1.73 m2 or greater. Main Outcomes and Measures: The outcomes of ESKD, defined as initiation of maintenance dialysis or receipt of a kidney transplant, and all-cause mortality were adjudicated from study entry until administrative censoring in 2018. Results: Among 4956 participants with mean (SD) age of 59.5 (10.5) years, 2152 (43.4%) were Black, 515 (10.4%) were Hispanic, and 2113 (42.6%) were White. There were 2156 (43.5%) women and 2800 (56.5%) men. At baseline, eGFRcys and eGFRcr values differed by more than 15 mL/min/1.73 m2 in one-third of participants (1638 participants [33.1%]). Compared with participants with similar baseline eGFRcys and eGFRcr (eGFRdiffcys-cr -15 to 15 mL/min/1.73 m2), those in whom eGFRcys was substantially lower than eGFRcr (eGFRdiffcys-cr < -15 mL/min/1.73 m2) had a higher risk of mortality (hazard ratio [HR], 1.86; 95% CI, 1.40-2.48) while those with eGFRdiffcys-cr of 15 mL/min/1.73 m2 or greater had lower risks of ESKD (subHR [SHR], 0.73; 95% CI, 0.59-0.89) and mortality (HR, 0.68; 95% CI, CI 0.58-0.81). In time-updated analyses, participants with eGFRdiffcys-cr less than -15 mL/min/1.73 m2 had higher risks of ESKD (SHR, 1.83; 95% CI, 1.10-3.04) and mortality (HR, 3.03; 95% CI, 2.19-4.19) compared with participants with similar eGFRcys and eGFRcr. Conversely, participants with eGFRdiffcys-cr of 15 mL/min/1.73 m2 or greater had lower risks of ESKD (SHR, 0.50; 95% CI, 0.35-0.71) and mortality (HR, 0.58; 95% CI, 0.45-0.75). Longitudinal changes in eGFRdiffcys-cr were associated with mortality risk. Compared with participants who had similar slopes by eGFRcys and eGFRcr, those with smaller eGFRcr declines had an 8-fold increased mortality risk (HR, 8.20; 95% CI, 6.37-10.56), and those with larger apparent declines by eGFRcr had a lower mortality risk (HR, 0.14; 95% CI, 0.08-0.24). Conclusions and Relevance: These findings suggest that large differences between eGFRcys and eGFRcr were common in persons with CKD. These differences and their changes over time may be informative of ESKD and mortality risks, warranting monitoring of both eGFRcys and eGFRcr in this high-risk population.

The effects of peritoneal dialysis on QT interval in ESRD patients.

BACKGROUND: Patients with chronic kidney disease (CKD) are at a high risk of fatal arrhythmias. The extended corrected QT (QTc) interval is a hallmark of ventricular arrhythmias and sudden cardiac death. Previous studies have shown that QT interval and QTc are prolonged with the decline in renal function. However, there were no available results for patients with peritoneal dialysis (PD). In this study, we examined changes in QT interval and QTc in patients with end-stage renal disease (ESRD) who underwent peritoneal dialysis. METHODS: A total of 66 ESRD patients who received PD, including 50 males and 16 females, with an average age of 43.56 ± 15.15 years, were enrolled. The follow-up lasted 1 year. The demographics and the etiology of patients were recorded. QTc and clinical/biochemical indexes before dialysis and at 6 and 12 months were determined and analyzed. Dialysis adequacy and peritoneal transport function were assessed in each patient. Analysis of variance (ANOVA), least significant difference (LSD) or Tamhane's T2, Paired T-test, Chi-square test, multiple linear regression analysis, and Pearson correlation coefficient were used to analyze the data. P < 0.05 was considered as statistically significant. RESULTS: With reference to etiology, 37 patients (56.06%) had chronic nephritis, and 11 (16.67%) had diabetic nephropathy. Most of the peritoneal transport functions were low average transport (25, 37.88%), while the least were high transport (2, 3.03%).During the follow-up period, all patients had adequate peritoneal dialysis. Compared with a baseline before dialysis, anemia, low albumin, blood pressure, blood urea nitrogen, creatinine, uric acid, potassium, calcium, phosphorus, and parathyroid hormone improved after 6 and 12 months, while the residual renal function gradually decreased during the follow-up. The mean QTc of all patients was stable during the follow-up period. According to gender, the QTc in males and female patients were similar. Before PD, diastolic blood pressure, calcium concentration, and hemoglobin level were negatively correlated with QTc in end-stage renal disease patients; After PD, the observed clinical indexes were no longer relevant to QTc. CONCLUSION: Unlike hemodialysis-induced QTc prolongation, PD did not increase the patient's QT interval and QTc interval, which suggested that myocardial electrical activity might be more stable in patients with adequate peritoneal dialysis.

Pathological right ventricular changes in synthesized electrocardiogram in end-stage renal disease patients and their association with mortality and cardiac hospitalization: a cohort study.

BACKGROUND: Right ventricular (RV) function is an important prognostic predictor for end-stage renal disease (ESRD) patients. Non-invasive evaluation of RV function by simple electrocardiogram (ECG) is not yet evident. The purpose of this article was to investigate the presence and association of pathological right ventricular changes in synthesized ECG with cardiac hospitalization and mortality. METHODS: A prospective cohort study of 137 ESRD patients (mean age: 56 years) were recruited from the hemodialysis unit in An-Najah National University Hospital, Nablus, Palestine. Synthesized ECG was done right before the hemodialysis (HD) session. The pathological right ventricular changes were recorded for each patient. The relationship between pathological RV changes and mortality, cardiac and non-cardiac hospitalization was assessed through a 6-months follow-up period. RESULTS: Right ventricular Q wave was found in 2.2% of patients, while right ventricular ST elevation was found in 0.7% of patients, and right ventricular negative T wave was found in 0.7% of patients. During the 6-month period of follow-up, 36 (26.3%) patients were hospitalized, nine patients (6.6%) due to cardiac causes. A total of 8 (5.83%) patients died, out of those 4 patients (2.91%) due to cardiac causes. Using Fisher's exact test, there was a significant association between pathological abnormalities in synthesized ECG and hospitalization among hemodialysis patients, (p = 0.047). Pathological changes in synthesized ECG were less prevalent in non-cardiac hospitalizations than in cardiac hospitalizations. CONCLUSIONS: The presence of pathological RV synthesized ECG changes can predict cardiac hospitalization in ESRD patients. Synthesized ECG is a good available tool that can be easily performed in ESRD patients. To determine whether Synthesized ECG can be used as a screening tool for pathological RV changes in a dialysis patients, more research with a larger number of patients and a longer follow-up period is required.

Association between exercise frequency with renal and cardiovascular outcomes in diabetic and non-diabetic individuals at high cardiovascular risk.

BACKGROUND: Guidelines recommend physical activity to reduce cardiovascular (CV) events. The association between physical activity and progression of chronic kidney disease (CKD) with and without diabetes is unknown. We assessed the association of self-reported physical activity with renal and CV outcomes in high-risk patients aged ≥ 55 years over a median follow-up of 56 months in post-hoc analysis of a previously randomized trial program. METHODS: Analyses were done with Cox regression analysis, mixed models for repeated measures, ANOVA and χ2-test. 31,312 patients, among them 19,664 with and 11,648 without diabetes were analyzed. RESULTS: Physical activity was inversely associated with renal outcomes (doubling of creatinine, end-stage kidney disease (ESRD)) and CV outcomes (CV death, myocardial infarction, stroke, heart failure hospitalization). Moderate activity (at least 2 times/week to every day) was associated with lower risk of renal outcomes and lower incidence of new albuminuria (p < 0.0001 for both) compared to lower exercise levels. Similar results were observed for those with and without diabetes without interaction for renal outcomes (p = 0.097-0.27). Physical activity was associated with reduced eGFR decline with a moderate association between activity and diabetes status (p = 0.05). CONCLUSIONS: Moderate physical activity was associated with improved kidney outcomes with a threshold at two sessions per week. The association of physical activity with renal outcomes did not meaningfully differ with or without diabetes but absolute benefit of activity was even greater in people with diabetes. Thus, risks were similar between those with diabetes undertaking high physical activity and those without diabetes but low physical activity. CLINICAL TRIAL REGISTRATION: http://clinicaltrials.gov.uniqueidentifier :NCT00153101.

Plasma potassium concentration and cardiac repolarisation markers, Tpeak-Tend and Tpeak-Tend/QT, during and after exercise in healthy participants and in end-stage renal disease.

PURPOSE: The cardiac T-wave peak-to-end interval (Tpe) is thought to reflect dispersion in ventricular repolarisation, with abnormalities in Tpe associated with increased risk of arrhythmia. Extracellular K+ modulates cardiac repolarisation, and since arterial plasma K+ concentration ([K+]) rapidly increases during and declines following exercise, we investigated the relationship between [K+] and Tpe with exercise. METHODS: Serial ECGs (Tpe, Tpe/QT ratio) and [K+] were obtained from 8 healthy, normokalaemic volunteers and 22 patients with end-stage renal disease (ESRD), at rest, during, and after exhaustive exercise. RESULTS: Post-exercise [K+] nadir was 3.1 ± 0.1, 5.0 ± 0.2 and 4.0 ± 0.1 mmol.L-1 (mean ± SEM) for healthy participants and ESRD patients before and after haemodialysis, respectively. In healthy participants, compared to pre-exercise, recovery-induced low [K+] was associated with a prolongation of Tpe (110 ± 8 vs. 87 ± 5 ms, respectively, p = 0.03) and an increase in Tpe/QT ratio (0.28 ± 0.01 vs. 0.23 ± 0.01, respectively, p = 0.01). Analyses of serial data revealed [K+] as a predictor of Tpe in healthy participants (ß = -0.54 ±0.05, p < 0.0001), in ESRD patients (ß = -0.75 ± 0.06, p < 0.0001) and for all data pooled (ß = -0.61 ± 0.04, p < 0.0001). The [K+] was also a predictor of Tpe/QT ratio in healthy participants and ESRD patients. CONCLUSIONS: Tpe and Tpe/QT ratio are predicted by [K+] during exercise. Low [K+] during recovery from exercise was associated with increased Tpe and Tpe/QT, indicating accentuated dispersion of ventricular repolarisation. The findings suggest that variations in [K+] with physical exertion may unmask electrophysiological vulnerabilities to arrhythmia.

Detection of impaired renal allograft function in paediatric and young adult patients using arterial spin labelling MRI (ASL-MRI).

The study aimed to discriminate renal allografts with impaired function by measuring cortical renal blood flow (cRBF) using magnetic resonance imaging arterial spin labelling (ASL-MRI) in paediatric and young adult patients. We included 18 subjects and performed ASL-MRI on 1.5 T MRI to calculate cRBF on parameter maps. cRBF was correlated to calculated glomerular filtration rate (GFR) and compared between patient groups with good (GFR ≥ 60 mL/min/1.73 m2) and impaired allograft function (GFR < 60 mL/min/1.73 m2). Mean cRBF in patients with good allograft function was significantly higher than in patients with impaired allograft function (219.89 ± 57.24 mL/min/100 g vs. 146.22 ± 41.84 mL/min/100 g, p < 0.008), showing a highly significant correlation with GFR in all subjects (r = 0.75, p < 0.0001). Also, the diffusion-weighted imaging (DWI-MRI) apparent diffusion coefficient (ADC) and Doppler measurements of peak-systolic and end-diastolic velocities and the resistive index (PS, ED, RI) were performed and both methods showed no significant difference between groups. ADC implied no correlation with GFR (r = 0.198, p = 0.464), while PS indicated moderate correlation to GFR (r = 0.48, p < 0.05), and PS and ED moderate correlation to cRBF (r = 0.58, p < 0.05, r = 0.56, p < 0.05, respectively). Cortical perfusion as non-invasively measured by ASL-MRI differs between patients with good and impaired allograft function and correlates significantly with its function.