[Cardiovascular calcification and five-years mortality in patients on maintenance hemodialysis]

The very high cardiovascular mortality and morbidity in hemodialyzed patients (HD) is strongly associated with cardiovascular calcification. The aim of the study was to find the predictors of mortality in HD patients during 5-years observation period. The study group was composed of 64 patients (35 F, 29 M) aged 25-75 years (mean 48.9) hemodialyzed three times a week for 12-275 months (mean 77.8). The levels of hemoglobin, total protein, albumin, Ca, P, Ca x P, iPTH, cholesterol, triglycerides, fibrinogen, insulin, homocysteine, leptin, procalcitonin, CRP, IL-6, TGF-beta, PDGF were assessed and all patients underwent Calcium Score (CS) of coronary arteries (CACS) calculation using MSCT and B-mode ultrasound of carotid arteries for intima-media thickness (CCA-IMT), as well as echocardiographic assessment with LVMI calculation and heart valves evaluation at the start of observation. The self-elaborated Cumulative Calcification Index (CCl) was calculated as a sum of CACS Index according to Rumberger et al. (CS<10-0, 10400 - 3 points); number of calcified plaques in carotid arteries (0-0, 1 - 1, 2 - 2, 3 and more - 3 points) and the number of calcified heart valves. At the start of the study the median value of CCl was 4 and interquartile range 4. Only 2 (3%) patients were free of any type of cardiovascular calcification (CCl =0), 15 (23%) patients had minimal calcification (CCl 1 to 2 points), 33 (52%) average (2 - 6 points) and 14 (22%) patients had severe calcification (CCl>6). 21 (32,8%) patients died during observation period. Patients who died were older (56.9 vs. 45.3 yrs.) and had higher CS at the start (1275 vs. 356), higher CCA-IMT (0.948 vs. 0.687 mm) and CCl (6.15 vs. 3.63) values. Those patients had also higher CRP (0.645 vs. 0.245 mg/dl) and IL-6 (10.16 vs. 4.15 pg/ml) levels (p<0.05). LVMI and mean: hemoglobin, total protein, albumin, Ca, P, Ca x P, iPTH, cholesterol, triglycerides, fibrinogen, insulin, homocysteine, leptin, procalcitonin, TGF-beta as well as PDGF levels did not differ between the groups. In logistic regression model (p<0.00002), among tested parameters only CCl was an independent and statistically significant factor of mortality with OR=1.82 per every point of CCl (p<0.0003). Cardiovascular calcification expressed as CCl confirmed to be a strong predictor of mortality in HD patients.