Vascular Calcification in Long-Term Haemodialysis Patients in a Single Unit: A Retrospective Analysis

Abstract

Vascular calcification (VC), which is described in the elderly and in diabetics, is frequently seen in uraemia. It is usually regarded as having little significance. We studied the roentgenological appearance of VC in a homogeneous group of 38 long-hours haemodialysis patients whose longevity on dialysis allowed sustained (10-25 years) follow-up, including annual skeletal surveys and thrice-yearly clinical examinations and biochemical profiles. We compiled a dossier of clinical and laboratory parameters from the start of dialysis to the present day. We were able to analyze the natural history of VC and to determine which clinical parameters were linked with progression. We found that VC became steadily more prevalent – at dialysis onset present in 39% of the patients, but in 92% after an average dialysis duration of 16 years, with 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 peripheral (digital arteries), seen alone in 3% of patients. Most patients (65%) had evidence of both types. Calcification was scored for site and severity. Patient age (r = 0.57, p < 0.001), systolic blood pressure (r = 0.54, p < 0.001), hyperparathyroidism (reduced progression after parathyroidectomy), 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 was a weak negative association between progression and serum ferritin (r = -0.33, p = 0.046). The reduced vessel compliance that results from VC is likely to be cardiovascularly deleterious. In severe cases, tissue perfusion or vascular access for haemodialysis can be compromised. VC and accelerated cardiovascular mortality are common to uraemia, diabetes, and systolic hypertension in the elderly. Better understanding of these pathological processes may permit intervention and possibly lead to a reduction in cardiovascular mortality.

Parathyroidectomy and Heart Rate Variability in Patients with Stage 5 CKD

“…A more recent investigation conducted by Sharma et al (44) observed significantly reduced rates of all-cause and cardiovascular mortality in 150 dialysis patients who underwent near-total parathyroidectomy relative to 1044 non-PTX control patients. Accumulating evidence showed that successful PTX in severe SHPT patients led to substantial cardiovascular benefits, including improvement in BP (11,45), amelioration of uremic tumoral calcinosis (46,47), decrease in thickness of coronary artery intima media (10), and reduction in left ventricular mass index (48). However, whether successful PTX can affect cardiac autonomic outflow in severe SHPT remains unclear.…”

Arteriovenous Access and Hand Pain

“…Whereas shunting of blood to a low-resistance area (arteriovenous access), resulting in hypoperfusion distal to the anastomosis, has been suggested as the cause, increased resistance to blood flow offered by the presence of arterial stenosis also can play a critical role (5,8 -10). Furthermore, distal arteriopathy that commonly is seen in patients with vascular calcification and diabetes may be an important factor that leads to the development of DHIS (11,12).…”

Mean arterial pressure and pulse pressure are associated with different clinical parameters in chronic haemodialysis patients

“…22 Elevated PTH levels and phosphorus concentration also lead to increased vascular calcification, which could explain the increase in PP values. 23 It is also possible that the association between raised PTH and phosphorus, and lower PP represents survival of those patients with the healthiest blood vessels for the longest period, while PTH and phosphorus concentration continue to rise in parallel with the duration of dialysis. 24 The impact of ultrafiltration and volume control on HD BP is a well-known fact.…”