Early Detection of Arteriovenous Fistula Stenosis in Hemodialysis Patients through Routine Measurements of Dialysis Dose (Kt/V).

BACKGROUND: Monitoring of arteriovenous (AV) fistula to detect hemodynamically important stenosis is crucial for the prevention of AV fistula thrombosis. The aim of our study was to analyze the importance of dialysis dose (Kt/V) during online postdilution hemodiafiltration (HDF) for early detection of AV fistula stenosis. METHODS: Hemodialysis patients with AV fistula were included in this study. We compared a group of 44 patients who have undergone fistulography and subsequently percutaneous transluminal angioplasty (PTA) of significant AV fistula stenosis (active group) with a group of 44 age- and sex-matched patients without PTA (control group). Observational time in both groups was the same. RESULTS: All patients had postdilution online HDF using a F5008 dialysis machine, which can measure online single-pool Kt/V. All data were analyzed during the performance of 2056 HDF procedures. In the active group, we found statistically significantly lower values of Kt/V, all 8 weeks before PTA. In the active group, there was a significant improvement in Kt/V in the first (p < 0.001) and second week (p = 0.049) after PTA. Three and 8 weeks after PTA, we did not find any statistically significant difference in Kt/V between both groups (p = 0.114; p = 0.058). Patients in the active group had statistically significantly lower substitution volumes and blood pump flow rates during HDF over the whole observation period before and after PTA. In contrast, there were no differences in venous pressure in the dialysis circuit between both groups throughout the observation period. CONCLUSION: In hemodialysis patients with AV fistula, treated with online HDF, routine measurements of Kt/V during each HDF are a beneficial, quick, and straightforward method for early detection of hemodynamically significant AV fistula stenosis.

CHA2DS2-VASc Score as a Predictor of Cardiovascular and All-Cause Mortality in Chronic Kidney Disease Patients.

INTRODUCTION: Chronic kidney disease (CKD) is a risk factor for cardiovascular and all-cause mortality. Recognition of high-risk patients is important and could lead to a different approach and better treatment. The CHA2DS2-VASc score was originally used to predict cerebral infarction in patients with atrial fibrillation (AF), but it is also a useful predictor of outcome in other cardiovascular conditions, independent of AF. Therefore, the aim of our research was to assess the role of CHA2DS2-VASc score in predicting cardiovascular and all-cause mortality in CKD patients. METHODS: Stable nondialysis CKD patients were included. At the time of inclusion, medical history data and standard blood results were collected and CHA2DS2-VASc score was calculated. Patients were followed till the same end date, until kidney transplantation or until their death. RESULTS: Eighty-seven CKD patients were included (60.3 ± 12.8 years, 66% male). Mean follow-up time was 1,696.5 ± 564.6 days. During the follow-up, 21 patients died and 11 because of cardiovascular reasons. Univariate Cox regression analysis showed that CHA2DS2-VASc score is a significant predictor of cardiovascular and all-cause mortality. In multivariate Cox regression analysis, in which CHA2DS2-VASc score, serum creatinine, urinary albumin/creatinine, hemoglobin, high-sensitivity C-reactive protein, and intact parathyroid hormone were included, CHA2DS2-VASc score was an independent predictor of cardiovascular (HR: 2.04, CI: 1.20-3.45, p = 0.008) and all-cause mortality (HR: 2.06, CI: 1.43-2.97, p = 0.001). The same was true after adding total cholesterol, triglycerides, and smoking status to both the analyses. CONCLUSION: The CHA2DS2-VASc score is a simple, practical, and quick way to identify the risk for cardiovascular and all-cause mortality in CKD patients.

Assessment of volume status with bioimpendance prior to hemodialysis and its importance for predicting survival in hemodialysis patients.

BACKGROUND: Optimal fluid management is a physician's everyday challenge in patients on maintenance hemodialysis (HD). Bioimpedance spectroscopy (BIS) is a non-invasive method to estimate body composition, including estimates of fluid overload (FO). Our study aimed to analyze the association between FO and the mortality rate in HD patients. MATERIALS AND METHODS: We performed a retrospective single-center cohort study in 92 HD patients. The body composition was measured before HD using the portable whole-body BIS device Body Composition Monitor (BCM). We have analyzed the mortality rates of HD patients in two FO groups, a standard definition FO group (> 1.1 L), and a severe FO group (> 2.5 L) and compared them to mortality rates of patients without FO or without severe FO, respectively. RESULTS: The mean age of patients was 64.3 ± 13.0 years, mean dialysis vintage 64 months, 60.9% were men. 68 (73.9%) patients had FO of > 1.1 L and 30 (32.6%) had FO of > 2.5 L. During the follow-up period of 1,020 ± 417 days, 29 (31.5%) patients died. Kaplan-Meier survival analysis showed that patients with FO > 2.5 L had worse survival (p = 0.039). In a Cox regression model, which included FO > 2.5 L, age, dialysis vintage, hemoglobin, C-reactive protein, and albumin, only FO > 2.5 L and advanced age turned out to be predictors of death (p = 0.044 and p = 0.001, respectively). CONCLUSION: HD patients with FO > 2.5 L before HD have poorer survival than patients with normohydration or lower overhydration.

Lung ultrasound, hemoglobin, and NT-proBNP in peritoneal dialysis patients.

BACKGROUND: Lung ultrasound (LUS) is a non-invasive technique for estimating extravascular lung water in patients with end-stage renal disease and heart diseases. In this study, we examined an association between the severity of lung congestion as detected by LUS B-lines (LUS comets), anemia, and serum biomarker N-terminal pro-brain natriuretic peptide (NT-proBNP) in peritoneal dialysis (PD) patients. MATERIALS AND METHODS: 19 patients, who were treated with PD in our dialysis center were enrolled. On the day of their routine check-up, we performed a lung auscultation, LUS on 28 typical locations and determined blood levels of hemoglobin and NT-proBNP. RESULTS: The average age of patients was 54 (range 30 - 71) years, the average duration of PD treatment was 53 (range 10 - 194) months, 63% (12) of the patients were male. Nine (47.4%) patients had peripheral edema, and only 1 (5.3%) patient had inspiratory crackles. Using LUS, we found mean 17 (range 1 - 87) lung comets. Mean hemoglobin level was 108.6 g/L (SD ± 10.4), mean NT-proBNP level 1,151 pmol/L (SD ± 1,077). We found a statistically significant correlation between the number of lung comets and hemoglobin level (r = -0.655; p = 0.002) and NT-proBNP (r = 0.759; p < 0.0001). Multiple regression analysis with the number of lung comets as dependent variable and hemoglobin and NT-proBNP levels as independent variables confirmed a statistically significant association between the number of lung comets and NT-proBNP (ß = 0.572; p = 0.009). CONCLUSION: In PD patients, the number of LUS comets is associated with hemoglobin and NT-proBNP.

Association between lung comets and subendocardial viability ratio in peritoneal dialysis patients.

AIMS: Pulmonary congestion is a direct result of either general overhydration or cardiac dysfunction. Lung ultrasonography (LUS) with lung B-lines (LUS comets) can be used to assess extravascular lung water in patients with end-stage renal disease on hemodialysis or peritoneal dialysis (PD). Subendocardial viability ratio (SEVR) is a pulse wave analysis parameter that is a non-invasive measure of coronary perfusion and is related to cardiac work and oxygen consumption. Our aim was to investigate the association between LUS comets and SEVR in PD patients. MATERIALS AND METHODS: We performed an observational study in 25 PD patients in a single dialysis center. Extravascular lung water was quantified by the number of LUS comets, using a portable ultrasound (US) device. LUS comets were recorded in each intercostal space and defined as hyperechoic US bundles at a narrow base extending from the transducer to the edge of the screen. The sum of LUS comets yields a score reflecting the extent of water accumulation in the lungs. SEVR was determined non-invasively by radial applanation tonometry. RESULTS: Mean age of patients was 54.7 ± 10.7 years, mean PD vintage 27 ± 33 (1 - 167) months, 60% were men. The mean number of LUS comets was 13 ± 19 (0 - 71), and the mean SEVR was 153 ± 40%. We found a statistically significant negative correlation between the number of LUS comets and SEVR (r = -0.467; p = 0.019). Multiple regression analysis with LUS comets as dependent variable, and SEVR and age as independent variables showed a statistically significant relationship between SEVR and the number of LUS comets (ß = -0.467, p = 0.021). CONCLUSION: Higher number of LUS comets is associated with lower SEVR in PD patients.

Chronic Kidney Disease and Obesity.

There is a pandemic of obesity worldwide and in Europe up to 30% of the adult population is already obese. Obesity is strongly related to the risk of CKD, progression of CKD, and end-stage renal disease (ESRD), also after adjustment for age, sex, race, smoking status, comorbidities, and laboratory tests. In the general population, obesity increases the risk of death. In nondialysis-dependent CKD patients, the association between body mass index and weight with mortality is controversial. In ESRD patients, obesity is paradoxically associated with better survival. There are only a few studies investigating changes in weight in these patients and in most weight loss was associated with higher mortality. However, it is not clear if weight change was intentional or unintentional and this is an important limitation of these studies. Management of obesity includes life-style interventions, bariatric surgery, and pharmacotherapy. In the last 2 years, a long-acting glucagon-like peptide-1 (GLP-1) receptor agonist and GLP-1 and glucose-dependent insulinotropic polypeptide receptor agonist were shown to be effective in managing weight loss in non-CKD patients, but we are awaiting results of more definitive studies in CKD patients.

Mineralocorticoid Receptor Antagonists in Diabetic Kidney Disease.

Diabetes mellitus is a global health issue and main cause of chronic kidney disease. Both diseases are also linked through high cardiovascular morbidity and mortality. Diabetic kidney disease (DKD) is present in up to 40% of diabetic patients; therefore, prevention and treatment of DKD are of utmost importance. Much research has been dedicated to the optimization of DKD treatment. In the last few years, mineralocorticoid receptor antagonists (MRA) have experienced a renaissance in this field with the development of non-steroidal MRA. Steroidal MRA have known cardiorenal benefits, but their use is limited by side effects, especially hyperkalemia. Non-steroidal MRA still block the damaging effects of mineralocorticoid receptor overactivation (extracellular fluid volume expansion, inflammation, fibrosis), but with fewer side effects (hormonal, hyperkalemia) than steroidal MRA. This review article summarizes the current knowledge and newer research conducted on MRA in DKD.

Diabetic patients with chronic kidney disease: Non-invasive assessment of cardiovascular risk.

The prevalence and burden of diabetes mellitus and chronic kidney disease on global health and socioeconomic development is already heavy and still rising. Diabetes mellitus by itself is linked to adverse cardiovascular events, and the presence of concomitant chronic kidney disease further amplifies cardiovascular risk. The culmination of traditional (male gender, smoking, advanced age, obesity, arterial hypertension and dyslipidemia) and non-traditional risk factors (anemia, inflammation, proteinuria, volume overload, mineral metabolism abnormalities, oxidative stress, etc.) contributes to advanced atherosclerosis and increased cardiovascular risk. To decrease the morbidity and mortality of these patients due to cardiovascular causes, timely and efficient cardiovascular risk assessment is of huge importance. Cardiovascular risk assessment can be based on laboratory parameters, imaging techniques, arterial stiffness parameters, ankle-brachial index and 24 h blood pressure measurements. Newer methods include epigenetic markers, soluble adhesion molecules, cytokines and markers of oxidative stress. In this review, the authors present several non-invasive methods of cardiovascular risk assessment in patients with diabetes mellitus and chronic kidney disease.

Oxidative Stress Markers in Chronic Kidney Disease with Emphasis on Diabetic Nephropathy.

Diabetes prevalence is increasing worldwide, especially through the increase of type 2 diabetes. Diabetic nephropathy occurs in up to 40% of diabetic patients and is the leading cause of end-stage renal disease. Various factors affect the development and progression of diabetic nephropathy. Hyperglycaemia increases free radical production, resulting in oxidative stress, which plays an important role in the pathogenesis of diabetic nephropathy. Free radicals have a short half-life and are difficult to measure. In contrast, oxidation products, including lipid peroxidation, protein oxidation, and nucleic acid oxidation, have longer lifetimes and are used to evaluate oxidative stress. In recent years, different oxidative stress biomarkers associated with diabetic nephropathy have been found. This review summarises current evidence of oxidative stress biomarkers in patients with diabetic nephropathy. Although some of them are promising, they cannot replace currently used clinical biomarkers (eGFR, proteinuria) in the development and progression of diabetic nephropathy.