CARDIOVASCULAR MORTALITY IN HEMODIALYSIS PATIENTS. ROLE OF HYPERTENSION AND OTHER CLINICAL FACTORS

Cardiovascular events (CVE) are the major cause of death in dialysis patients (HDP). Mortality rate for CVE in this population is as high as 50% and many fold greater than that of general population. Hypertension is present in 60-90% of HDP and it is regarded as one of the major risk factor for CVE. In this retrospective study the incidence of fatal CVE and the role of hypertension on CV mortality was evaluated in HDP. Patients died from 1982 to 2002 were evaluated and divided, according to fatal events, in cardiovascular- (CVP) and non cardiovascular-patients (NCVP). AMI, sudden death, death heart failure, stroke were considered as CVE. Systolic (SBP), diastolic (DBP) and mean (MAP) blood pressure values pertinent to 13 dialysis sessions (i.e. 1 month of dialysis treatment) were recorded and averaged for statistical analysis. Other factors taken into account were: age, duration of renal failure and dialysis treatment, pre and post-dialysis body weight (BW), intra-dialysis BW loss, urea, uric acid and phosphorus, alkaline phosphatase, PTH, plasma cholesterol (COL) and triglycerides (TRIG), total serum proteins and albumin, haemoglobin, Ht, serum ferritin. All parameters were evaluated at 12, 6 and 1 month (baseline) before death. Blood pressure was measured both before and after dialysis session. Patients were n. 139; male: 71 (51%), female: 68 (49%); mean age: 69 ± 10 y (range: 41-96 y); duration of renal failure: 53±67 months (range: 0 to 336 months); duration of dialysis: 52,6±46 months (range: 0 to 206 months). CVE were observed in 59% of patients. Compared to NCVP, in CVP we found: higher age (71.4 ± 9.5 vs. 67.6 ± 11; P<0.001), longer duration of renal failure (56 ± 75 months vs. 48 ± 55; p< 0.001), shorter duration of haemodialysis (48 ± 44 months vs. 59 ± 48; p< 0.001); higher COL TRIG and haemoglobin (p<0.05). Of interest no difference of blood pressure (systolic, diastolic, mean blood pressure) was found between CVP and NCVP at baseline, 6 and 12 months before final event; however, blood pressure significantly decreased from 12 to 1 month in CVP. BW progressively decreased from 12 months to baseline (p<0.01) in CVP, while it increased (p<0.01) in NCVP. In conclusion, mortality in HDP is not dependent on hypertension being baseline blood pressure similar in both CVP and NCVP. Nevertheless the progressive reduction of blood pressure long before the fatal event, the progressive decline of BW, duration of renal failure may be regarded as predictive factors for CVE. Keywords: blood pressure; haemodialysis: outcome; heart; renal failure: end-stage Session: Poster Session II: Cardiac disease in haemodialysis patients