Carotid stiffness change over the cardiac cycle by ultrafast ultrasound imaging in healthy volunteers and vascular Ehlers-Danlos syndrome.

OBJECTIVES: Arterial stiffness is related to age and collagen properties of the arterial wall and can be indirectly evaluated by the pulse wave velocity (PWV). Ultrafast ultrasound imaging, a unique ultrahigh frame rate technique (>10, 000 images/s), recently emerged enabling direct measurement of carotid PWV and its variation over the cardiac cycle. Our goal was to characterize the carotid diastolic-systolic arterial stiffening using ultrafast ultrasound imaging in healthy individuals and in vascular Ehlers-Danlos syndrome (vEDS), in which collagen type III is defectuous.

METHODS: Ultrafast ultrasound imaging was performed on common carotids of 102 healthy individuals and 37 consecutive patients with vEDS. Results are mean ± standard deviation.

RESULTS: Carotid ultrafast ultrasound imaging PWV in healthy individuals was 5.6 ± 1.2 in early systole and 7.3 ± 2.0  m/s in end systole, and correlated with age (r = 0.48; P < 0.0001 and r = 0.68; P < 0.0001, respectively). Difference between early and end-systole PWV increased with age independently of blood pressure (r = 0.54; P < 0.0001). In patients with vEDS, ultrafast ultrasound imaging PWV was 6.0 ± 1.5 in early systole and 6.7 ± 1.5  m/s in end systole. Carotid stiffness change over the cardiac cycle was lower than in healthy people (0.021 vs. 0.057  m/s per mmHg; P = 0.0035).

CONCLUSION: Ultrafast ultrasound imaging can evaluate carotid PWV and its variation over the cardiac cycle. This allowed to demonstrate the age-induced increase of the arterial diastolic-systolic stiffening in healthy people and a lower stiffening in vEDS, both characterized by arterial complications. We believe that this easy-to-use technique could offer the opportunity to go beyond the diastolic PWV to better characterize arterial stiffness change with age or other collagen alterations.