Neointimal hyperplasia and calcification in medium sized arteries in adult patients with chronic kidney disease

The nature of arterial changes resulting in cardiovascular events and dialysis vascular access failures in adult predialysis patients is not well known. This study examined intimal changes, calcium deposition, and consequent stiffness in brachial and radial arteries of adult CKD patients. Ten brachial-artery and seven radial-artery specimens were obtained during fistula creation from nine predialysis and eight dialysis-dependent, nondiabetic patients; and age-gender matched controls undergoing coronary bypass grafts (6 radial) or kidney donation (6 renal). Arterial stiffness was measured at baseline. Vessel histology, morphometric analysis of intima-media, and direct quantification of calcium load was performed using standard techniques. Both predialysis and dialysis patients demonstrated significant arterial intimal hyperplasia with intima:media ratio higher than controls (0.13 ± 0.12 vs. 0.02 ± 0.05, p = 0.01). Calcium deposition was demonstrated on histology and the calcium content in patients was higher than controls (34.68 ± 26.86 vs. 10.95 ± 9.18 microg/microg, p = 0.003). The blood vessel calcium content correlated with arterial stiffness (r = 0.64, p = 0.018). This study for the first time describes, and suggests mechanistic linkage between, intimal hyperplasia, pathological calcium deposition, and increased functional arterial stiffness in dialysis and predialysis patients. Our research could serve as a unique window into the in vivo status of the uremic vasculature impacting fistula maturation and cardiovascular disease.