Large and small artery compliance changes during hemodialysis

Background: Cardiovascular disease is the major cause of mortality and morbidity in patients undergoing hemodialysis. Reduced arterial compliance is an independent predictor of cardiovascular mortality in end stage renal disease and can be measured noninvasively using pulse wave analysis technology. Methods: Ten chronic hemodialysis patients were evaluated using pulse wave analysis to determine large and small vessel compliance before hemodialysis, midway through the treatment, and at the end of the treatment. Serum calcium was measured before and after hemodialysis. Results: No significant changes in systolic blood pressure (BP), diastolic BP, pulse pressure, or heart rate occurred during hemodialysis. A significant decrease in small vessel compliance (C2) occurred during the treatment, with the mean C2 decreasing from 5.6 ± 2.7 mL/mm Hg × 10 predialysis to 3.3 ± 1.5 mL/mm Hg × 10 midway through the treatment (P = .04) and to 3.9 ± 4.3 mL/mm Hg × 10 at the end of the dialysis treatment. There was no significant change in large vessel compliance (C1). Serum calcium increased significantly during the dialysis treatment from 8.0 ± 1.2 mg/dL to 9.8 ± 0.9 mg/dL (P = .003). Conclusions: Significant decreases in small artery compliance occur without systolic or diastolic BP changes during routine hemodialysis. A significant increase in serum calcium also occurred during hemodialysis. Measurements of arterial compliance during hemodialysis may be an important tool to identify patients with vascular responses, which may place them at greater risk for cardiovascular disease.