Change of CAVI in Maintenance Hemodialysis Patients

Lee, Tae Woo; Kang, Eung Taeck; Shin, Jin Hee; Yu, Soo Jung; Oh, Dong Jin; Yu, Suk Hee

Abstract

BACKGROUND
CAVI, Cardio Ankle Vascular Index, has been proposed as an independent marker of arterial stiffness regardless of the blood pressure. We measured the CAVI of hemodynamically unstable patients on maintenance hemodialysis and at the same time measured other pulse pressure-related parameters in order to study their correlations with each other.
METHODS
We studied 85 patients undergoing maintenance hemodialysis over 3 months. We categorized patients into 4 subgroups: Diabetes+Hypotension (N= 12), Diabetes+Normal blood pressure (N=16), Non- diabetes+Hypotension (N=15), and Non-diabetes+Normal blood pressure (N=42). Using automatic waveform analyzer, we measured CAVI and pulse pressure- related markers twice, before and after the hemodialysis session, and observed the change.
RESULTS
After the dialysis, CAVI did not change despite the decreased mean blood pressure. Yet both brachial and ankle pulse pressure dropped significantly (4.34+/-15.22 mmHg, 11.50+/-20.65 mmHg, p<0.01). PEP (Pre-Ejection Period) on the other hand, remarkably increased (12. 13+/-22.18 msec) while ET (Ejection Time) showed considerable decrease (35.86+/-45.68 msec), and PEP/ ET ratio increased as well. Predialysis CAVI was significantly higher in Diabetes group than in Non-diabetes (11.02+/-2.33 vs. 8.20+/-1.87, p<0.001). However, no significant difference of CAVI was observed between Hypotension and Normal blood pressure groups. Diabetes+Hypotension Group displayed reduction in CAVI after dialysis with marginal significance (0.68+/-1.07, p=0.05) whilst PEP, ET and PEP/ET ratio showed no significant change compared to other groups.
CONCLUSION
CAVI, a newly developed marker of arterial stiffness, is expected to be useful in prediction of the cardio-vascular risk and prognosis of patients undergoing hemodialysis.