VASCULAR CALCIFICATION IN LONG-TERM HEMODIALYSIS-PATIENTS IN A SINGLE-UNIT - A RETROSPECTIVE ANALYSIS

Vascular calcification (VC), which is described in the elderly and in diabetics, is frequently seen in uraemia. It is usually regarded as ha ving little significance. We studied the roentgenological appearance o f VC in a homogeneous group of 38 long-hours haemodialysis patients wh ose longevity on dialysis allowed sustained (10-25 years) follow-up, i ncluding annual skeletal surveys and thrice-yearly clinical examinatio ns and biochemical profiles. We compiled a dossier of clinical and lab oratory parameters from the start of dialysis to the present day. We w ere able to analyze the natural history of VC and to determine which c linical parameters were linked with progression. We found that VC beca me steadily more prevalent - at dialysis onset present in 39% of the p atients, but in 92% after an average dialysis duration of 16 years, wi th a mean onset 9.7 years after starting dialysis. As well as becoming more prevalent, the calcification became progressively more severe in most patients. There were two patterns of VC: axial (aorta and iliac and femoral arteries), seen alone in 32% of the patients, and peripher al (digital arteries), seen alone in 3% of patients. Most patients (65 %) had evidence of both types. Calcification was scored for site and s everity. Patient age (r = 0.57, p < 0.001), systolic blood pressure (r = 0.54, p < 0.001), hyperparathyroidism (reduced progression after pa rathyroidectomy), plasma phosphate (r = 0.34, p = 0.042), and vitamin D concentrations (r = 0.53, p < 0.001) were the principal determinants of severity and rate of progression of VC in this population. There w as a weak negative association between progression and serum ferritin (r = -0.33, p = 0.046). The reduced vessel compliance that results fro m VC is likely to be cardiovascularly deleterious. In severe cases, ti ssue perfusion or vascular access for haemodialysis can be compromised . VC and accelerated cardiovascular mortality are common to uraemia, d iabetes, and systolic hypertension in the elderly. Better understandin g of these pathological processes may permit intervention and possibly lead to a reduction in cardiovascular mortality.