Arterial Micro-Calcification of Vascular Access is Associated with Aortic Arch Calcification and Arterial Stiffness in Hemodialysis Patients

Vascular calcification of the coronary arteries or aorta is an independent risk factor for cardiovascular outcome, but clinical significance of arterial micro-calcification (AMC) of vascular access is unclear in hemodialysis (HD) patients. Sixty-five patients awaiting vascular access operation were enrolled. We compared surrogate markers of cardiovascular morbidity such as aortic arch calcification (AoAC) by chest radiography, arterial stiffness by brachial-ankle pulse wave velocity (baPWV) and endothelial dysfunction by flow-mediated dilatation (FMD) between patients with and without AMC of vascular access on von Kossa staining. AMC of vascular access was detected in 36 (55.4%). The AMC-positive group had significantly higher incidence of AoAC (63.9% vs. 20.7%, p<0.001) and higher baPWV (26.5 +/- 9.4m/s vs. 19.8 +/- 6.6m/s, p=0.006) than the AMC-negative group. There was no significant difference in FMD between the two groups (5.4 +/- 2.6% vs. 5.7 +/- 3.5%, p=0.764). The AMC-positive group had higher incidence of diabetes mellitus, higher systolic blood pressure and wider pulse pressure than the AMC-negative group. This study suggests that AMC of vascular access may be associated with cardiovascular morbidity via AoAC and arterial stiffness in HD patients.