Objective: The cardio-ankle vascular index (CAVI) could be obtained by measuring pulse wave velocity (PWV) and blood pressure (BP). This method is associated with various technical drawbacks. We evaluated the accuracy and usefulness of CAVI measured by ultrasound via detecting the aortic and ankle flow directly by ultrasonic probe.
Methods: CAVI was determined in 96 subjects [64 male, mean age (41.2 +/- 8.9) years] who took part in the annual check up program in our department by means of the professional equipment (BP-203RPEII, VP-1000, Japan, CAVIp), the M-mode (CAVIm) and color Doppler flow imaging (CAVId). Measurement reproducibility on was obtained by repeat the measurements in 20 subjects choose randomly from the 96 subjects. Carotid ultrasound (CU) was performed to obtain intima-media thickness (IMT) and beta index in all subjects.
Results: CAVI obtained by various methods were similar and comparable (CAVIm 7.74 +/- 1.62, CAVId 7.77 +/- 1.59, CAVIp 8.74 +/- 1.57, all P > 0.05). Inter-group and inter-observer variance was negligible (r1 = 0.98, r2 = 0.97). There were also significant correlations between CAVIm and IMT, CAVIm and beta (r1 = 0.824, r2 = 0.812, all P < 0.01), and between CAVId and IMT, CAVId and beta (r1 = 0.815, r2 = 0.813, all P < 0.01).
Conclusions: CAVI could be correctly measured by ultrasound technique.