Reference Values of Carotid Ultrafast Pulse-Wave Velocity: A Prospective, Multicenter, Population-Based Study.

BACKGROUND: Ultrafast ultrasound imaging has been demonstrated to be an effective method to evaluate carotid stiffness through carotid pulse-wave velocity (PWV) with high reproducibility, but a lack of reference values has precluded its widespread use in clinical practice. The aims of this study were to establish reference values of PWV for ultrafast ultrasound imaging in a prospective, multicenter, population-based cohort study and to investigate the main determinants of carotid PWV. METHODS: A total of 1,544 healthy Han Chinese volunteers (581 men [38%]; age range, 18-95 years) were enrolled from 32 collaborating laboratories in China. The participants were categorized by age, blood pressure (BP), and body mass index (BMI). Basic clinical parameters and carotid PWV at the beginning of systole (BS) and at end-systole (ES) were measured using ultrafast ultrasound imaging techniques. RESULTS: PWV at both BS and ES was significantly higher in the left carotid artery than in the right carotid artery. PWV at BS was significantly higher in men than in women; however, no significant difference was noted in PWV at ES between men and women. Multiple linear regression analyses revealed that age, BP, and BMI were independently correlated with PWV at both BS and ES. PWV at BS and ES progressively increased with increases in age, BP, and BMI. Furthermore, age- and sex-specific reference values of carotid PWV for ultrafast ultrasound imaging were established. CONCLUSIONS: Reference values of carotid PWV for ultrafast ultrasound imaging, stratified by sex and age, were determined for the first time. Age, BP, and BMI were the dominant determinants of carotid PWV for ultrafast ultrasound imaging, which should be considered in clinical practice for assessing arterial stiffness.

Absent atherosclerotic risk factors are associated with carotid stiffening quantified with ultrafast ultrasound imaging.

OBJECTIVES: To evaluate carotid stiffening in participants without conventional cardiovascular risk factors (CVRFs) by using ultrafast pulse wave velocity (ufPWV). METHODS: The present study enrolled 517 participants without conventional CVRFs (CVRF-Free total population). Subjects in this population were defined as current non-smokers with untreated blood pressure < 140/90 mmHg, fasting blood glucose (FBG) < 7.0 mmol/L, total cholesterol (TC) < 6.2 mmol/L, low-density lipoprotein cholesterol < 4.1 mmol/L, and high-density lipoprotein cholesterol ≥ 1.0 mmol/L. Participants in the subgroup with optimal CVRFs (CVRF-Optimal subgroup; n = 188) were defined as having blood pressure < 120/80 mmHg, TC < 5.2 mmol/L, and FBG < 5.6 mmol/L. Clinical interviews, physical examinations, serum draw, carotid intima-media thickness (cIMT), and ufPWV were evaluated. Adjusted odds ratios (ORs) with 95% confidence intervals and ordinal logistic regression models were used. RESULTS: Carotid stiffening was present in 46.2-54.5% of CVRF-Free subjects. Age, male sex, and body mass index (BMI) were independently associated with carotid stiffening in both the CVRF-Free total population and CVRF-Optimal subgroup (OR for age = 1.10-1.11, OR for male sex = 2.65-7.19, OR for BMI = 1.34-1.62; p < 0.05). Carotid stiffening was associated with TC only in the CVRF-Free total population (OR for TC = 1.84; p = 0.034). CONCLUSIONS: Many CVRF-Free individuals have carotid stiffening. ufPWV for atherosclerotic stiffening aids the assessment of early atherogenesis and may further clarify the true status of healthy adults without CVRFs. KEY POINTS: • CVRF-Optimal individuals have a lower carotid stiffness than CVRF-Free populations. • ufPWV is a quantitative predictor for the early assessment of AS. • Absent major CVRFs cannot be considered low risk for carotid stiffening and atherosclerosis.