SP688SIMPLE VASCULAR CALCIFICATION SCORE:IS IT USEFULL IN ASSESMENT OF PROGNOSIS OF HEMODIALYSIS PATIENTS?

Abstract

Introduction and Aims: Aim of the study - to evaluate relation between vascular calcification (VC) assesed by simple vascular calcification score (SVCS) and outcomes in chronic hemodialysis patients. Objectives: 1. To evaluate prevalence of VC in hemodialysis patients using SVCS based on plain radiography; 2. To analyse possible relationship among Ca-P metabolism disorders, VC and risk of death in hemodialysis patients; 3. To assess VC impact on survival of hemodialysis patients. Methods: The SVCS was evaluated in all prevalent chronic hemodialysis patients (n=95) in Hospital of Lithuania University of Health Sciences starting February 2013. The analysis of plain radiographic films of pelvis and hands was performed by single radiologist blinded to clinical data as it is described by Adragao et al. (Nephrology Dialysis Transplantation (2004) 19;1480-88) with SVCS >3 considered as cut off value. For the analysis patients were divided into two groups: group 1- SVCS <3, group 2- SVCS >3. Age, HD vintage, clinical and demographical data as well as biochemical parameters (Ca, ionized Ca, P, PTH, AP, total cholesterol, albumin, hemoglobin) were collected on the day of VC assesment from medical records of each patient. Variables were expressed as frequencies for discrete factors and mean values for continues factors. Comparison was performed using two tailed chi-square test for categorical variables and Students t- test for continuous variables, with p value <0,05 considered as statistical significant. The independent variables associated with death were tested with Cox regression models, using age, sex, hemodialysis vintage, diabetes, Ca, P, PTH, Ca-P product, cholesterol and vascular scores as covariates. Kaplan -Meier survival curves of patients with SVCS >3 and <3 were compared by long- rank test. Statistical analysis was performed using SPSS packages. Results: Data of 54 (56,8%) male and 41 (43,2%) female patients were analysed. 19 patients (20%) were diabetic. Mean age was 61,01+/-15,7 year, hemodialysis vintage-39,7 +/-46,2 months. During the observational period of 23 month there were 11 (11,6%) all-cause deaths. SVCS <3 was detected for 38 (40%) patients and SVCS >3 - 57 (60%) patients. No statistical significant differences were observed in sex distribution, cardiovascular diseases and hypertension frequency comparing patients between the groups. The hemodialysis vintage did not differ significantly, but group 2 patients were significantly older (1 group-54,37+/-15,6, 2 group-65,44+/-14,39, p=0,001) and had diabetes more often (1 group-3 (7,9%) 2 group-16 (28,1%), p=0,016). Biochemical parameters did not differ significantly between the groups. Cox regresion analysis revealed no statistical significant diference of relative risk of death with regards to HD vintage, age, sex, diabetes mellitus, Ca, P, PTH, Ca-P product, cholesterol. Only higher SVCS was associated with 1,3 times higher relative risk of death (95% CI 1,032-1,681, p=0,027). Kaplan-Meier analysis revealed that the cumulative hazard of death at 23 months was higher in patients of group 2 (2,7% vs 17,5%, long-rank-4,6, p=0,032). Conclusions: 1. More than half of prevalent hemodialysis patients had signifficant VC detected by plain radiography. 2. Patients with SVCS >3 were significantly older and had diabetes more often but no statistical significant differences between groups were observed evaluating biochemical markers reflecting calcium-phosphate metabolism. 3. Higher risk of death in studied hemodialysis patients population was associated only with prevalent VC