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 > or = 90% agreement on the presence of CIMT > or = 75th percentile and > or = 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.