Reduction of arteriovenous access blood flow leads to biventricular unloading in haemodialysis patients.

AIMS: Patients on chronic haemodialysis have a wide range of changes in cardiac function and structure, including left ventricular hypertrophy, dilation and diastolic dysfunction or pulmonary hypertension. All these changes were linked to increased mortality in previous studies. High-flow arteriovenous fistulas (AVF) are supposed to be a factor contributing to their development. This study investigated the early effect of surgical AVF blood flow (Qa) reduction on these changes in patients with or without heart failure changes. METHODS AND RESULTS: Forty-two patients in chronic haemodialysis programme with high-flow AVF (Qa over 1500 mL/min), indicated for surgery for ≥1 of the following indications: 1.manifest heart failure; 2.hand ischemia; 3.advanced structural heart changes detected by echocardiography. The patients underwent echocardiography on selection visit, before blood flow reducing surgery and six weeks thereafter. The Qa reduction led to decrease of left ventricular mass (p = 0.02), end-diastolic volume (p = 0.008), end-diastolic diameter (p = 0.003) and left atrial volume (p = 0.0006). Diastolic function improved. Similarly, right ventricular diameter and right atrial volume decreased (p = 0.000001 and 0.00009, respectively) together with the decrease of estimated pulmonary artery systolic pressure. 81% of patients suffered from pulmonary hypertension prior to surgery, only 36% thereafter. CONCLUSION: The surgical restriction of the hyperkinetic circulation leads to several improvements of heart structure and function, which was linked to higher mortality in other studies. The beneficial effect of Qa reduction is present even in patients without symptoms of heart failure. The contribution of AVF must be considered with structural or functional heart changes.

Diastolic dysfunction in asymptomatic hemodialysis patients in the light of the current echocardiographic guidelines.

The prevalence of the left ventricular hypertrophy (LVH) is very high in end-stage renal disease treated by hemodialysis. Diastolic dysfunction is a frequent consequence and leads to the development of heart failure with preserved ejection fraction. New American/European echocardiographic guidelines for the assessment of diastolic function simplified the evaluation and were published recently. The aim of this study was to reveal if the new guidelines stratify asymptomatic hemodialysis patients by the levels of brain-natriuretic peptide (BNP). A cohort of 46 patients hemodialyzed in one center with the lack of overt heart failure, systolic dysfunction, arrhythmia or significant valvular disease were examined by echocardiography before and after a single hemodialysis and blood samples for BNP analysis were drawn at both occasions. The LVH was present in 53% of patients, concentric remodeling in another 17%. Higher indexed left ventricular mass was related to higher BNP levels (r = 0.58, p = 0.0001). Before hemodialysis, diastolic dysfunction was present in 61%: grade 1 in 25%, grade 2 in 21% and grade 3 in 8%. The higher grade of diastolic dysfunction was associated with the incremental increase of BNP. The post-dialysis echocardiography did not allow the assessment of diastolic function in as many as 37% of patients. Our study has shown that the application of the current guidelines for the assessment of diastolic function based on simple four criteria differentiate hemodialysis symptomless patients with preserved systolic function according to BNP levels. BNP levels also rose together with the left ventricular mass. The ratio E/e' medial seemed to be a better predictor of increased BNP than E/e' lateral or E/e' averaged.

Decrease of muscle strength in vascular access hand due to silent ischaemia.

BACKGROUND:: Creation of vascular access leads to considerable local haemodynamic changes with decreased hand perfusion. Distal limb tissues then represent a model of hand ischaemia effect on muscles. The aim of our study was to investigate how the presence of vascular access influences the hand muscle strength in end-stage renal disease patients. METHODS:: We included 52 chronically haemodialysed patients with upper limb access without clinical signs of hand ischaemia. Muscle strength was evaluated by dynamometry. Finger pressure was measured on the second and fourth fingers and averaged for further analysis. Thenar tissue oxygenation (rSO2) was analysed using near-infrared spectroscopy. All examinations were performed in both the hands. Basic laboratory analysis was added. Data were processed with unpaired t-test and correlation analysis. RESULTS:: Hands with dialysis access had lower values of handgrip strength (54.2 ± 29.1 lbs vs 48.6 ± 23.4 lbs, p = 0.0006), systolic finger pressure (127.1 ± 32.0 mmHg vs 101.4 ± 31.6 mmHg, p < 10-8) and of thenar rSO2 (45.8% ± 12.9% vs 42.5% ± 13.3%, p = 0.002). Muscle strength (handgrip) was directly related to the thenar oxygenation ( r = 0.36; p = 0.014) and to the finger systolic pressure ( r = 0.38; p = 0.007) on the access extremity. On the extremity without dialysis access, handgrip strength was inversely related to patient's age ( r = -0.41, p = 0.003), dialysis vintage ( r = -0.32, p = 0.02) and red cell distribution width ( r = -0.37, p = 0.01). CONCLUSION:: The presence of dialysis access leads to the decrease of finger pressure, oxygenation, and also muscle strength even in the absence of clinically overt hand ischaemia. All these parameters are interrelated. This study underlines the consequences of inadequate muscle perfusion.

Low Cerebral Oxygenation Is Associated with Cognitive Impairment in Chronic Hemodialysis Patients.

BACKGROUND/AIMS: High rates of cognitive impairment (CI) are an alarming problem in patients undergoing chronic hemodialysis (HD). Its pathophysiology remains unclear and there are indications that brain ischemia might be one of the key causes. Cerebral tissue oxygenation, as measured by near-infrared spectroscopy, is known to be decreased in HD patients. However, it is unknown whether CI is associated or not associated with lower cerebral oxygenation in these patients. The primary aim of our study was to probe this possible association. Our secondary aim was to assess other factors possibly related to cerebral ischemia and CI. METHODS: Thirty-nine patients treated by chronic HD were included in this cross-sectional study. All measurements were performed before the initiation of an HD session. The Montreal Cognitive Assessment (MoCA) was administered according to published recommendations. Regional saturation of oxygen (rSO2) of the left frontal lobe was measured using the INVOS 5100C device. Basic medical history and laboratory data were recorded, and handgrip strength was analyzed. We used the unpaired t test to compare the rSO2 and other variables between cognitively normal patients (MoCA score ≥26) and those who displayed CI (MoCA score <26). Multiple linear regression analysis was used to adjust for principal confounders. RESULTS: Cognitively impaired patients had lower brain rSO2 values compared to cognitively normal patients (48 ± 9 vs. 57 ± 10%, p = 0.01). Among other variables, higher red cell distribution width (15.8 ± 1.9 vs. 13.8 ± 1.6%, p = 0.01) and lower hand grip strength (49.2 ± 23.3 vs. 99.3 ± 31.4 lbs, p < 0.001) also displayed a significant association with CI. The relation between rSO2 and MoCA score was significant after adjustment for age and gender (p = 0.007). CONCLUSION: Decreased brain oxygenation is associated with weaker cognitive performance in patients undergoing chronic HD. Further understanding the causes of cerebral ischemia in HD patients could lead to the prevention of cognitive decline in this population.

Tissue ischemia worsens during hemodialysis in end-stage renal disease patients.

BACKGROUND: Cognitive deficit is a common problem in end-stage renal disease (ESRD) patients. Ultrafiltration and hemodialysis lead to profound hemodynamic changes. The aim of this pilot study was to describe brain and hand oxygenation values in ESRD patients and their changes during hemodialysis. METHODS: Twenty-seven patients treated by chronic hemodialysis and 17 controls patients of the same age were included in the study. Regional saturation of oxygen (SrO2) was measured at the brain frontal lobe and at the hand with dialysis access using the INVOS 5100C. In 17 of ESRD patients, SrO2 was also monitored throughout hemodialysis. Finger systolic blood pressure and basic hemodialysis and laboratory data were collected. RESULTS: Dialysis patients had lower brain and also hand SrO2 values at rest (51.5 ± 10.9 vs. 68 ± 7%, p<0.0001 and 55 ± 16 vs. 66 ± 8%, p = 0.03, respectively). Both values further decreased during the first 35 minutes of hemodialysis (brain SrO2 to 47 ± 8%, p<0.0001 and hand to 45 ± 14%, p<0.0001, respectively). The brain SrO2 decrease was related to the ultrafiltration rate, the hand SrO2 decrease to the finger pressure and to blood hemoglobin. CONCLUSIONS: Chronic dialysis patients suffer from tissue ischemia and that even worsens after the beginning of hemodialysis. This observation may contribute to the understanding of cognitive deficit etiology.

Long-term outcome of patients with ANCA-associated vasculitis treated with plasma exchange: a retrospective, single-centre study.

BACKGROUND: Plasma exchange (PLEX) has been used routinely for treatment of severe renal vasculitis and/or alveolar haemorrhage (AH) in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), but the long-term benefit of PLEX in AAV remains unclear. We aimed to describe the characteristics and outcomes of patients treated with PLEX in a single centre. METHODS: Patients with AAV were identified by performing a case review of medical records of 705 patients who received PLEX in a single tertiary referral centre between 2000 and 2010. Patient characteristics and outcomes were recorded. The Kaplan-Meier method, log-rank tests and Cox regression analysis were used for survival analyses. RESULTS: A total of 94 patients with AAV were identified (44 men, 50 women; median age 60 years, range 21-90 years; 52 proteinase 3-ANCA, 41 myeloperoxidase-ANCA and 1 ANCA-negative; 8 double-positive for ANCA and anti-glomerular basement membrane; 93 newly diagnosed/1 relapse; 55 [58.5 %] required dialysis). The reasons for initiating PLEX therapy were severe renal involvement alone in 52 %, AH in 10 %, both renal involvement and AH in 35 %, and "other" in 3 %. The patients had 3-27 (median 7) PLEX sessions. At 3 months, 81 (86 %) of 94 were alive and 62 (66 %) of 94 were alive and dialysis-independent. The median follow-up was 41 months (minimum-maximum 0.5-137 months), when 56 (59.6 %) of 94 patients were alive and 47 (50 %) were dialysis-independent. The estimated overall survival rates were 75.3 % at 1 year and 61.1 % at 5 years. Patient survival decreased with increasing age at presentation (5-year survival 85 % for age <50 years, 64.4 % for ages 50-65 years, and 41 % for >65 years; p < 0.01 for comparison between all groups). Estimated renal survival rates were 65.5 % at 1 year and 43 % at 5 years. Renal survival was worse in patients aged >65 years than in the younger patients (5-year survival 25.1 % in patients >65 years vs. 50.8 % for those ≤65 years, p < 0.01). The estimated renal survival was better in patients with higher Disease Extent Index (DEI) >6 than in patients with DEI ≤6 (5-year survival 52.1 % vs. 39.4 %, p = 0.04), even though this was not confirmed in multivariate analysis. CONCLUSIONS: The mortality of patients presenting with severe manifestations of AAV remains high despite the use of PLEX. Older age at presentation is associated with worse overall and renal prognosis.

Left Atrial Dysfunction in End-Stage Renal Disease Patients Treated by Hemodialysis.

BACKGROUND: Repeated inter-dialysis water retention contributes to the development of left ventricular hypertrophy and failure, which is responsible for significant mortality of end-stage renal disease (ESRD) patients. The left atrium has a thin wall, which makes it even more prone to preload changes. In the general population with heart failure with preserved ejection fraction (HFpEF), left atrial function is even worse than that in patients with reduced ejection fraction. We hypothesized that repeated water retention is related to left atrial dysfunction in ESRD patients treated by hemodialysis and that the expected changes would be related to the brain natriuretic peptide (BNP) levels. METHODS: Forty six patients were enrolled. Left atrial end-diastolic and end-systolic volumes and left atrial ejection fraction (LAEF) were recorded by echocardiography just before and just after dialysis and then analyzed offline. Moreover, BNP was analyzed also prior to dialysis and after. Effects of dialysis were tested using paired t test and the correlation analysis was applied to test associations. RESULTS: LAEF was inversely related to the dialysis vintage (r = -0.62, p = 0.001) and patient's age (r = -0.48, p = 0.005) and it did not increase after dialysis despite the decrease of left atrial volume. BNP was related to left atrial volume index (r = 0.45, p = 0.019) and to LAEF (r = -0.57, p = 0.003). CONCLUSIONS: LAEF is decreased especially in long-term dialyzed patients and does not improve after dialysis despite the decrease of left atrial volume. Inadequate contractility reserve of the left atrium is similar to the non-ESRD patients with HFpEF and might help explain the high prevalence of heart failure in ESRD patients.

[Theralite and multiple myeloma]. / Theralite a mnohocetný myelom.

Multiple myeloma associated with an increased FLC production causes renal failure (cast nephropathy) requiring dialysis. Theralite is a dialyser with a high cut-off membrane (HCO) - with large size pores that allow permeability for substances of molecular masses up to 45 kDa. The FLC concentrations over hemodialysis will significantly decrease and if hematological treatment is also effective, the FLC production will significantly fall as well. The aim of this comprehensive therapy is to improve the renal functions to such an extent that a substantial removal of FLC (70-90 %) is reached in patients and even interruption of dialysis therapy (50-75 %). The number of HD with this membrane rather varies in individual patients according to the literature (e.g. an average of 12 HDs/per 1 patient - 3-45). Our cohort comprised 17 patients aged 38-71 years, with 9 HDs per 1 patient, 10 patients (59 %) stopped the dialysis therapy and 7 remained on the dialysis programme. FLC removal reached 87 % in the whole cohort after the completed HDs with Theralite, but it specifically reached 93 % in the patients without further dialysis therapy, as opposed to 75 % in those who continued to undergo HD. No patient died when receiving HD with Theralite, in 4 complications occurred without causing interruption of the therapy. We assume that monitoring FLC concentrations before each dialysis may be of prognostic significance for patients including the length of treatment with an HCO membrane. Close cooperation with a hematologist is necessary.Key words: cast nephropathy - FLC - HCO membrane - multiple myeloma - kidney failure - Theralite.

Plasma calprotectin in chronically dialyzed end-stage renal disease patients.

OBJECTIVE: The current study aimed to evaluate plasma calprotectin levels and clearance end-stage renal disease (ESRD) patients with and without acute infection undergoing chronic hemodialysis (HD). MATERIALS AND METHODS: Blood samples from 54 HD patients were obtained before and after the HD and 42 healthy blood donors were examined as controls. The blood levels of calprotectin, procalcitonin, C-reactive protein (CRP), and intracellular production of interleukins 10 and 12 in monocytes were determined in both groups. RESULTS: The concentrations of plasma calprotectin in ESRD patients were significantly higher than in healthy controls (p < 0.05). No differences between pre- and post-HD calprotectin plasma levels were observed (p = 0.07 for two-tailed test). Plasma calprotectin levels were not significantly influenced by the presence of acute infection (p = 0.19) or diabetes (p = 0.42). A significant positive correlation of plasma calprotectin to plasma beta-2 microglobulin was proven (p < 0.05). Procalcitonin (PCT), CRP, IL-10, and IL-12 were not correlated with plasma calprotectin before or after HD. The elevation of plasma calprotectin was correlated strongly to the hemodialysis vintage (r = 0.55, p < 0.01). CONCLUSIONS: Significantly elevated levels of plasma calprotectin in ESRD patients occur without an acute infectious cause and are not affected by the presence of diabetes. By analogy to plasma beta-2 microglobulin, a close relation of plasma calprotectin to HD vintage was shown.

Effect of preload reduction by hemodialysis on conventional and novel echocardiographic parameters of left ventricular structure and function.

BACKGROUND: Available studies of the effect of hemodialysis (HD) on left ventricular (LV) performance brought ambiguous results. Therefore we aimed to investigate the effect of acute preload reduction induced by HD on conventional and novel parameters of LV structure and function. METHODS: Thirty-six patients underwent echocardiography 1 hour prior to and 1 hour following regular HD. M-mode, two-dimensional, and Doppler echocardiography were used to analyze conventional LV structural and functional parameters. Systolic and diastolic mitral annular velocities assessed by pulsed-wave tissue Doppler echocardiography (PW-TDE) and flow propagation velocity (Vp) of early LV inflow were measured as novel indices of LV systolic and diastolic function. RESULTS: After HD, all heart chambers including LV significantly reduced in their size. The reduction in LV mass was also observed. Parameters of LV systolic function-ejection fraction and systolic mitral annular velocity, significantly improved, whereas fractional shortening did not. As for LV diastolic function, conventional Doppler parameters and Vp were substantially changed after HD. Conversely, PW-TDE diastolic velocities were not significantly affected. CONCLUSIONS: The fluid removal induced by HD leads to a substantial decrease in LV size and mass. The improvement of LV longitudinal contraction documented by PW-TDE seems to be responsible for the increase in global LV systolic function after HD. While standard Doppler parameters of LV diastolic function and Vp are significantly affected by preload reduction, PW-TDE diastolic indices appears to be less load dependent. Therefore, PW-TDE represents a promising method for the LV diastolic function assessment in patients on HD.