Carotid Intima-Media Thickness Testing by Non-Sonographer Clinicians: The Office Practice Assessment of Carotid Atherosclerosis Study

Background: The purpose of this study was to determine whether a non-sonographer clinician (NSC) could obtain ultrasound images of the carotid artery, measure carotid intima-media thickness (CIMT), and identify findings indicating increased cardiovascular risk in an office setting. Methods: Eight NSCs from five sites were trained to use a handheld ultrasound device to screen the carotid arteries for plaques and to measure CIMT. Results: NSCs scanned 150 subjects who provided 900 images, of which 873 (97%) were interpretable. Differences between NSCs and the core laboratory were small (0.002 ± 0.004 mm) and bioequivalent (P_TOST < 0.05) with a low coefficient of variation (3.9% ± 0.5%). There was ≥ 90% agreement on the presence of CIMT ≥ 75th percentile and ≥ 80% agreement on plaque presence. Conclusions: This is the first multicenter study to show that NSCs can obtain images of the carotid arteries using a handheld ultrasound device, accurately measure CIMT, and identify findings indicating increased cardiovascular risk.