Laurynas Rimševičius

Photoplethysmography-Based System for Atrial Fibrillation Detection During Hemodialysis

Renal replacement therapy, such as hemodialysis, is the only effective treatment for the end-stage renal disease. Hemodialysis is directly associated with significantly increased risk of developing atrial fibrillation (AF). Since physicians must stop the procedure of hemodialysis when AF occurs, timely detection of AF is crucial. Electrocardiography could provide a reliable way for AF monitoring, but due to a routine of the procedure, it is not convenient enough for hemodialysis patients. Furthermore, electrocardiography increases the costs due to increased workload of medical staff. Therefore, as an alternative, we present a concept of unobtrusive AF monitoring during hemodialysis. The proposed system covers both hardware and software: a wearable device, capable of recording photoplethysmogram (PPG), and an online low complexity AF detection algorithm, applied for decision making. We tested this system on a pre-recorded PPG, containing both AF and normal rhythm episodes. Results show that the low power unobtrusive PPG wearable device has a potential to be applied for real-time AF detection using solely the PPG.

Usefulness of pretransplant aortic arch calcification evaluation for kidney transplant outcome prediction in one year follow-up

Abstract Vascular calcification (VC) is linked to post-transplant cardiovascular events and hypercalcemia which may influence kidney graft function in the long term. We aimed to evaluate whether pretransplant aortic arch calcification (AoAC) can predict post-transplant cardiovascular or cerebrovascular events (CVEs), and to assess its association with post-transplant plasma calcium levels and renal function in one-year follow-up. Our single-center observational prospective study enrolled 37 kidney transplant recipients (KTR) without previous history of vascular events. Two radiologists evaluated pretransplant AoAC on chest X-ray as suggested by Ogawa et al. in 2009. Cohen’s kappa coefficient was 0.71. The mismatching results were repeatedly reviewed and resulted in consensus. Carotid-femoral (cfPWV) and carotid-radial pulse wave velocity (crPWV) was measured using applanation tonometry before and one year after transplantation. Patient clinical, biochemical data, and cardiovascular/CVE rate were monitored within 1 year. We found out that eGFR1year correlated with eGFRdischarge and calcium based on hospital discharge data (β = 0.563, p = .004 and β = 51.360, p = .026, respectively). Multivariate linear regression revealed that donor age, donor gender, and recipient eGFRdischarge (R-squared 0.65, p = .002) better predict eGFR1year than AoAC combined with recipient eGFRdischarge (R-squared 0.35, p = .006). During 1-year follow-up, four (10.81%) patients experienced cardiovascular events, which were predicted by PWV ratio (HR 7.549, p = .045), but not related to AoAC score (HR 1.044, p = .158). In conclusion, KTR without previous vascular events have quite low cardiovascular/CVE rate within 1-year follow-up. VC evaluated as AoAC on pretransplant chest X-ray together with recipient eGFRdischarge could be related to kidney function in one-year follow-up.

A case of successfully treated relapsing peritoneal dialysis-associated peritonitis caused by Gordonia bronchialis in a farmer

Gordonia species are aerobic, weakly acid-fast, Gram-positive pathogens that rarely cause human infections, usually in immunocompromised patients. It is uncommon bacilli in cases of peritoneal dialysis-related peritonitis. The small number of infections with Gordonia species reported for humans may be stipulated by the difficulty in identifying the organism using conventional techniques. Careful review of Gram stains and modified-acid-fast stains should be done, so that confusion with other actinomycetes is minimized, pending the genotypic identification. Here we report a case that was caused by Gordonia bronchialis and thus required different considerations of treatment.

[LB.01.16] FACTORS RELATED TO LEFT VENTRICULAR HYPERTROPHY IN ONE YEAR FOLLOW-UP OF HEMODIALYSIS PATIENTS

Objective: The phenomenon of cardiac remodeling in dialysis population which leads to high prevalence of cardiovascular disease is every day burden for nephrologists. We aimed to analyze which factors could better indicate the presence of left ventricular hypertrophy in dialysis population. Design and method: 60 stable hemodialysis patients were screened for a prospective study. 45 patients had all data and met the inclusion criteria (no previous cardiovascular events, no cerebrovascular events). The calculated effect size for this population is 0.4052 (&agr; 0.05, &bgr; 0.90). Blood tests (including beta2-microglobulin, cystatin C), carotid femoral pulse wave velocity (cfPWV), left ventricular mass (LVM) and index, left ventricular end diastolic diameter, relative wall thickness, mean wall thickness and left ventricular ejection fraction were evaluated twice, average 1 year apart was also tested. Results: LVM and LVM index correlated with cystatin C level (r = 0.5141, p = 0.0085 and r = 0.4381, p = 0.0284 respectively), beta2-microglobulin concentration (r = 0.5759, p = 0.0025 and r = 0.5136, p = 0.0086 respectively). Change in LVM and LVM index within one year follow-up correlated with change in cfPWV (r = 0.5201, p = 0.0468 and r = 0.5518, p = 0.0266 respectively). Left ventricular end diastolic diameter, and MWT also strongly correlated with beta2-microglobulin and cystatinC. The strongest relationship revealed by linear regression indicated that for an increase of 1 m/s in cfPWV the expected increase in LVM index is 5.505 g/m2 (r-squared 0.3695, p = 0.3244, 95%CI [1.38;9.62]). During one year follow up the reverse cardiac remodeling was observed in some patients. Conclusions: Change in carotid-femoral pulse wave velocity within 1 year in dialysis population without previous cardiovascular or cerebrovascular events is associated with change in LVM index and has better descriptive value than cystatin C or beta2-microglobulin.

[LB.02.18] DIFFERENCE BETWEEN CAROTID-FEMORAL AND CAROTID-RADIAL PULSE WAVE VELOCITY CAN INDICATE THE EXTENT OF AORTIC ARCH CALCIFICATION IN DIALYSIS PATIENTS

Objective: Aortic arch calcification (AoAC) score evaluated on plain chest X-ray was proven to be associated with increased cardiovascular risk. We aimed to determine whether the difference between carotid-femoral pulse wave velocity (CFPWV) and carotid-radial pulse wave velocity (CRPWV) could describe the extent of AoAC in dialysis patients. Design and method: This cross-sectional study included 61 dialysis patients without previous vascular events. They all underwent chest X-ray. Two radiologists blinded to patient medical records graded aortic arch calcification (AoAC) by using a scale from 0 to 3 (grade0–no visible calcification, grade1 - < 50% calcification in the arch, grade2 - >50% calcification, grade3–circumferential calcification). These patients had their CFPWV and CRPW measured and the difference (&dgr;PWV=CFPWV-CRPWV) calculated. Biochemical blood tests included creatinine, urea, uric acid, cystatin C, ferritin, protein, albumin, C-reactive protein (CRP), calcium, phosphate, parathormone, total cholesterol, haemoglobin, platelets, white blood cells. Corrected total calcium and calcium phosphate products were calculated. According to AoAC grade patients were divided into 3 groups: group A–AoAC grade0, group B–grade1, group C–grade2, 3. Results: Patients with AoAC were significantly older, shorter in height, had higher than 25 kg/m2 body mass index (BMI), lower peripheral and central diastolic BP, lower end systolic BP, higher CRP levels. Group B had significantly lower phosphate and calcium phosphate product levels. We observed that patients with AoAC had higher CFPWV, but lower CRPWV values. &dgr;PWV was as follows: A -0,05, B 1,72, C 4,23, p = 0,115. On multivariate logistic regression models group A was significantly associated with &dgr;PWV (OR 0.48), albumin level (OR 0.69), diastolic BP (OR 1.13), BMI (OR 0.68) and time on dialysis (OR 0.99); group C–with &dgr;PWV (OR 1.73) and phosphate (OR 1.25). In group B the association was only with CRPWV (OR 0.50), BMI (OR 1.17), &dgr;PWV had no significant influence. Conclusions: The discrepancy between CFPWV and CRPWV measurement confirms different pattern of elastic vessels (Aorta) and muscular conduit arteries (radial arteries) and can describe the extent of aortic arch calcification in dialysis patients.

Successful adsorption of anti-A/B antibodies with multiple personal use columns in AB0 incompatible kidney recipients: A single centre experience.

Laurynas Rimsevicius,* Roberta Bagarauskyte, Antanas Griskevicius, Judita Audzijoniene, Laimonas Griskevicius, and Marius Miglinas Nephrology Center, Vilnius University Hospital Santariskiu Klinikos, Vilnius 08661, Lithuania Clinic of Gastroenterology, Nephrourology and Surgery, Faculty of Medicine, Vilnius University, Vilnius 03101, Lithuania Hematology, Oncology and Transfusion Medicine Center, Vilnius University Hospital Santariskiu Klinikos, Vilnius 08661, Lithuania Clinics of Internal, Family Medicine and Oncology, Faculty of Medicine, Vilnius University, Vilnius 03101, Lithuania

Development of Multi-parameter Analyser based on Electrochemical Urea Biosensors and Electrolyte Electrodes for Monitoring of Hemodialysis Patients

The idea of developing multi-parameter urea analyser comprising urea, Na+ and K+ selective electrodes has been considered. For this purpose the urea biosensors based on urease and recombinant urease working in amperometric and potentiometric way were developed. The working parameters of both urea biosensors were studied and optimized. Possibilities of real samples analysis using the developed biosensors were shown by measuring urea concentrations in blood dialysate taken from patients with renal failure. Both the potentiometric and the amperometric biosensors demonstrated high degree of signal reproducibility (the relative standard deviation of responses did not exceed 5 %). Change of sodium and potassium concentrations during blood hemodialysis is dangerous life-threatening condition and their monitoring is an important feature of point-of-care analyser. For this purpose high integrity commercial Na+ and K + selective electrodes were analysed and our own signal amplification and processing system proposed.

OS 19-09 Bioelectrical impedance phase angle as intradialytic hypotension predictor.

Objective: Water balance and blood pressure (BP) alterations are strongly associated in haemodialysis (HD) patients. Aim of this study was to determine whether bioelectrical impedance analysis (BIA) parameters can be used as predictors of intradialytic hypotension (IDH). Design and Method: We conducted an observational study of chronic HD patients. BIA was measured before the HD procedure using InBody S10 (Biospace, Seoul, Korea) body composition analyzer. Intracellular water (ICW), extracellular water (ECW), total body water (TBW), ECW/TBW ratio and phase angle (PhA) were selected as markers of hydration state and thus possible predictors of IDH. Patients had their BP registered during the HD. NKF KDOQI guidelines were used to define the IDH group. These patients had SBP drop of ≥ 20 mmHg or MAP drop of 10 mmHg or more. The BIA parameters and other IDH predictors were entered into multivariate logistic regression analysis with forward model selection process. Results: 99 patients were enrolled into the study. More than a half were male patients 51.5 % (n = 51), on dialysis for 4.5 [2.0–8.5] years with mean Charlson co-morbidity index of 5.76 ± 2.23. The rate of IDH was 40.4 % (n = 40). The mean values of the BIA parameters were as follows: ICW (23.11 ± 5.20), ECW (15.45 ± 3.474), TBW (38.56 ± 8.59), ECW/TBW ratio (0.40 ± 0.013) and PhA (4.49 ± 0.98). Multivariate analysis of IDH predictors revealed the lower PhA (OR = 1.70 CI95% 1.07–2.68 p = 0,024) and higher SBP prior the procedure (OR = 1.03 CI95% 1.01–1.05 p = 0,011) as the risk factors. Conclusions: In our study, we report that nearly half of HD patients experience IHD episode. We conclude that BIA PhA can be used to evaluate the risk of IHD, providing basis for HD adjustment.

Rationale of screening for early kidney damage in patients with high cardiovascular risk: nephrologist’s point of view

Summary Increased awareness of chronic kidney disease stimulates an interest towards early detection and prevention. The true prevalence of kidney injury varies from 10 to 40%, mostly depending on the methodology of the study and the population enrolled. A screening strategy targeting the highest risk groups, those with diabetes or hypertension, family history of diabetes, hypertension, or kidney disease, is likely to be most efficient and cost effective. Quantification for albuminuria should be performed using laboratorymethods or albumin to creatinine ratio and should be monitored at regular intervals. The most correct equations calculating glomerular filtration rate differ in separate populations, and the most accurate equations in patients with high cardiovascular risk are MDRD and CKD-EPI. Markers of early kidney damage have association with other target organs damage, even in subclinical or preclinical mode. Individuals at stage 4 and 5 chronic kidney disease, with higher levels of proteinuria, proteinuria together with haematuria, rapidly declining glomerular filtration rate, or poorly controlled hypertension should be referred to a nephrologist in order to identify the cause, provide recommendations, slow progression, or treat complications.

753 THE INFLUENCE OF AGEs ON KIDNEY FUNCTION AMONG PATIENTS WITH METABOLIC SYNDROME

Objectives: The aim of this study was to evaluate the impact of advanced glycation end-products (AGEs) on kidney function among patients with metabolic syndrome. Methods: The retrospective cohort study included 249 patients, who were investigated in a tertiary medical centre from 2011-08-01 till 2011-12-01 and matched NCEP metabolic syndrome criterions. Kidney function was evaluated by albuminuria and glomerular filtration rate, calculated by MDRD formula. AGEs were measured using non-invasive device, the skin autofluorescence reader. AGEs were classified into three groups: 1st-from 0.9 to 1.6 (n = 70), 2nd-from 1.7 to 1.9 (n = 82), 3rd-from 2.0 to 4.0 (n = 97). The kidney function was compared to the amount of AGEs. The data was analysed by using SPSS 19.0 programs. Results: Among 249 patients, there were 159 (63.9%) women and 90 (36.1%) men. Mean age was 53.88 ± 6.18. According to the amount of albumins in urine, specimens were ascribed as normoabuminuria (89.16%), microalbuminuria (10.04%) and macroalbuminuria (0.80%). Analysing albuminuria with AGEs groups, there was no correlation found (p > 0.05). According to GFR, we distributed three groups: GFR >90mls/min/1.73m2, or normal GFR (63.14%), 60-89mls/min/1.73m2, or slightly declined GFR (35.59%), 30–59mls/min/1.73m2, or stage 3 chronic kidney disease (1.27%). We found a negative correlation between GFR and AGEs rates (Pearson correlation coefficient r = 0.232, p < 0.0001). When comparing the distribution of GFR among AGEs’ groups, we found a statistically significant difference between 1st and 3rd groups (p = 0.013). Conclusions: The quantity of AGEs is not associated with the amount of albumins in urine, but higher amount of AGEs do correlate with decreased GFR.