Variability and reproducibility of carotid structural and functional parameters assessed with transcutaneous ultrasound – Results from the SAPALDIA Cohort Study

• Published in: Atherosclerosis 2013-12, Vol.231 (2), p.448-455
• Main Authors: Caviezel, Seraina, Dratva, Julia, Schaffner, Emmanuel, Teynor, Alexandra, Baumstark, Manfred W, Schindler, Christian, de Groot, Eric, Burdet, Luc, Rothe, Thomas, Pons, Marco, Gaspoz, Jean-Michel, Rochat, Thierry, Künzli, Nino, Probst-Hensch, Nicole, Schmidt-Trucksäss, Arno
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; adults; Aged; Aged, 80 and over; air pollution; Arterial stiffness; atherosclerosis; biomarkers; Blood Pressure; Cardiovascular; carotid arteries; Carotid Arteries - diagnostic imaging; Carotid Arteries - pathology; Carotid Intima-Media Thickness; Cohort Studies; Common carotid artery; compliance; Diameter; Elastic Modulus; Female; Follow-Up Studies; Health Surveys; heart; heart diseases; Humans; Intima media thickness; Male; Middle Aged; modulus of elasticity; Observer Variation; Prognosis; Regression Analysis; Reproducibility; Reproducibility of Results; Risk; Switzerland; ultrasonics; Ultrasonography - methods; Ultrasound
• ISSN: 0021-9150; 1879-1484
• DOI: 10.1016/j.atherosclerosis.2013.10.010

Abstract Objective Carotid intima media thickness (CIMT) and local stiffness are vascular biomarkers of atherosclerotic burden. We investigated the variability and reproducibility of clinically relevant structural (CIMT, lumen diameter) and functional parameters (strain, distensibility, compliance, β-stiffness index, Peterson's elastic modulus and Young's elastic modulus) measured in B-mode ultrasound sequences of the common carotid artery in the second follow up of the S wiss Cohort Study on A ir P ollution a nd L ung and Heart D iseases I n A dults (SAPALDIA3). Methods Ultrasound sequential images were examined twice over a 1 cm segment across at least one heart cycle in 165 SAPALDIA3 participants. To assess variability and reproducibility of structural and functional parameters, individual coefficients of variation (CV), intraclass correlation (ICC), Bland–Altman plots and mixed effect regressions were used. Results ICCs of repeated examinations ranged between 0.67 and 0.77 for blood pressure indices, between 0.87 and 0.97 for structural properties and between 0.75 and 0.79 for functional parameters. CV was lowest in structural parameters (1.6–4.6%), followed by blood pressure (5.1–7.9%) and functional indices (11.0–13.1%). Variations in all parameters were predominantly explained by subjects (>74% in functional, >82% in structural properties). Bland–Altman plots for functional indices showed mean and standard deviation of the respective mean value of 4.2(19.6)% for strain, 1.9(24.4)% for distensibility, 2.4(22.2)% for compliance, 3.0(24.4)% for β-stiffness index, 0.9(25.7)% for Peterson's elastic modulus and 1.2(27.9)% for Young's elastic modulus. Conclusion The results show that SAPALDIA3 measurements of transcutaneous ultrasound examinations have an excellent reproducibility of structural parameters and a good reproducibility of functional indices.