Progressive vascular calcification over 2 years is associated with arterial stiffening and increased mortality in patients with stages 4 and 5 chronic kidney disease

Abstract

Background and objectives: Vascular calcification is increasingly recognized as an important component of cardiovascular disease in chronic kidney disease. The objective of this study was to investigate prospectively the determinants, cardiovascular functional consequences, and survival associated with vascular calcification over 24 mo.

Design, setting, participants, & measurements: A total of 134 patients (60 on hemodialysis, 28 on peritoneal dialysis, and 46 with stage 4 chronic kidney disease) were studied. Vascular calcification of the superficial femoral artery was assessed using multislice spiral computed tomography; pulse wave velocity; all medications and time-averaged biochemical parameters were recorded at baseline and 12 and 24 mo.

Results: A total of 101 patients remained at 24 mo. Progressive calcification was seen in 58 of 101 patients. Most (31 of 46) patients with an initial calcification score of zero did not develop calcification. The hemodialysis group demonstrated a greater degree of progression than patients who were on peritoneal dialysis or had stage 4 chronic kidney disease. Progressive calcification was associated with age, male gender, serum alkaline phosphatase, beta blockers, and lipid-lowering agents. Increases in vascular calcification correlated with increased arterial stiffness. Vascular calcification was present in 20 of 21 patients who died. Cox proportional hazard analysis identified change in calcification score, calcium intake from phosphate binders, and low albumin as risk factors for death.

Conclusions: Patients with stages 4 and 5 chronic kidney disease and preexisting vascular calcification exhibit significantly increased calcification over 24 mo. Rapid progression of calcification is associated with arterial stiffness and mortality.