Abstract 10609: Coronary Saphenous Vein Bypass Graft Atherosclerosis in Patients with Chronic Kidney Disease: More Calcification, but Less Vasoconstrictor Potential
Background: Stent implantation into stenotic saphenous vein aorto-coronary bypass grafts (SVG) induces the release not only of particulate debris, but also of soluble vasoconstrictor substances, which contribute to microvascular impairment. Patients with chronic kidney disease (CKD) have more pronounced coronary calcification. We have now addressed the amount of calcium along with the potential for vasoconstriction in the aspirate of patients with and without CKD who underwent stenting for a severe SVG stenosis under protection with a distal occlusion/aspiration device.
Methods: Patients with CKD and without CKD were classified according to their glomerular filtration rate (≤60 ml/min, n=15 vs. >60 ml/min, n=11). Virtual histology based on intravascular ultrasound (IVUS) analysis was used to determine the dense calcium volume in the atherosclerotic vascular wall before stent implantation. Coronary arterial blood was retrieved before and during stent implantation and subdivided into particular debris, which was retained on a filter, and plasma. The calcium concentration of particular debris was analyzed by flame atomic absorption spectrometry. Using a bioassay of rat mesenteric arteries with intact (+E) and denuded (-E) endothelium, the vasoconstrictor response to coronary aspirate plasma was quantified and normalized to that by potassium chloride (KClmax=100%).
Results: Angiographic stenosis severity, IVUS-assessed lumen, plaque volumen and vessel area were comparable between groups. Dense calcium volume was 14±4% in patients with CKD vs. 4±1% in those without CKD (p<0.05); also, the calcium concentration in the particulate debris was 20±2mg/L in patients with CKD vs. 9±3mg/L in those without CKD (p<0.05). Aspirate plasma from patients with CKD induced less vasoconstriction than that from patients without CKD (+E, 13±5%; -E, 30±12% of KClmax vs. +E, 67±18%; -E: 122±19% of KClmax; p<0.01). Data are mean±SEM; comparison by t-test or two-way analysis of variance.
Conclusion: The graft atherosclerosis of patients with chronic kidney disease is -expectedly - more calcified, but - somewhat unexpectedly- more innocent in terms of vasoconstrictor release during stent implantation.
- © 2011 by American Heart Association, Inc.