January 30, 2015Open Access
Ambulatory Recording of Wave Reflections and Arterial Stiffness during Intra- and Interdialytic Periods in Patients Treated with Dialysis
Key Result
In patients on maintenance hemodialysis, the augmentation index was lower during dialysis compared to the interdialytic period of Day 1 (24.7% vs 26.8%, P<0.001).
Study Design
Type
Observational (n=153)
Multicenter
Yes
Structured PICO
How do wave reflections and arterial stiffness vary during intra- and interdialytic intervals in patients undergoing hemodialysis?
P
Population
153 patients receiving maintenance hemodialysis who underwent ambulatory BP monitoring over a midweek dialysis session and the subsequent interdialytic period.
E
Exposure
Ambulatory blood pressure monitoring with the Mobil-O-Graph device over a midweek dialysis session and the subsequent interdialytic period
O
Outcome
Variation of augmentation index (AIx) and pulse wave velocity (PWV) during intra- and interdialytic intervalssurrogate
In hemodialysis patients, wave reflections (AIx) gradually increase during the interdialytic period, while arterial stiffness (PWV) shows only slight elevation on the day off dialysis.
Main Result
Absolute Event Rate: 24.7% vs 26.8%
p-value: p=<0.001
Abstract
BACKGROUND AND OBJECTIVES: Wave reflections and arterial stiffness are independent cardiovascular risk factors in ESRD. Previous studies in this population included only static recordings before and after dialysis. This study investigated the variation of these indices during intra- and interdialytic intervals and examined demographic, clinical, and hemodynamic variables related to arterial function in patients undergoing hemodialysis. DESIGN, SETTING, PARTICIPANTS, P<0.001). In contrast, PWV remained unchanged between these intervals (9.31±2.2 versus 9.29±2.3 m/sec; P=0.60). Both AIx and PWV increased during dialysis-off day (Day 2) versus the out-of-dialysis period of Day 1 (28.8%±9.8% versus 26.8%±9.4% P<0.001 and 9.39±2.3 versus 9.29±2.3 m/sec P<0.001). Older age (odds ratio OR, 1.09; 95% confidence interval 95% CI, 1.02 to 1.15), female sex (OR, 7.56; 95% CI, 1.64 to 34.81), diabetic status (OR, 8.84; 95% CI, 1.76 to 17.48), and higher mean BP (OR, 1.17; 95% CI, 1.09 to 1.27) were associated with higher odds of high AIx; higher heart rate was associated with lower odds (OR, 0.71; 95% CI, 0.63 to 0.80) of high AIx. Older age (OR, 2.04; 95% CI, 1.61 to 2.58) and higher mean BP (OR, 1.15; 95% CI, 1.05 to 1.27) were independent correlates of high PWV. CONCLUSIONS: This study showed a gradual interdialytic increase in AIx, whereas PWV was only slightly elevated during Day 2. Future studies are needed to elucidate the value of these ambulatory measures for cardiovascular risk prediction in ESRD.