Focused Vascular Ultrasound for the Assessment of Atherosclerosis: A Proof-of-Concept Study

Abstract

Background: Current decisions to refer for angiographic coronary assessment are based on pain character, risk scores, stress testing, and occasionally calcium scoring. Carotid plaque has emerged as an effective vascular biomarker, but the cost and time of a full carotid ultrasound examination are disadvantageous. Focused vascular ultrasound (FOVUS) is a rapid limited assessment of carotid plaque that can be conducted by non-vascular-trained operators. The objective of the study was to determine the test characteristics of FOVUS for the assessment of significant coronary atherosclerosis in symptomatic patients referred for cardiac assessment.

Methods: In this prospective study, FOVUS was performed in 208 outpatients at low to intermediate risk undergoing same-day angiography. Carotid artery maximal plaque height was measured in each participant. A previously established receiver operating characteristic curve determined that a value of ≥1.5 mm was the threshold for significant angiographic coronary artery disease. FOVUS scan results, alone or combined with stress testing, were analyzed for the prediction of significant coronary artery disease.

Results: The negative predictive value and sensitivity of plaque height alone by FOVUS were found to be 77% and 93%, respectively. Adding the FOVUS scan result to stress testing significantly increased the negative predictive value and sensitivity of these traditional risk stratification tools.

Conclusions: Rapid carotid plaque height measurement by FOVUS enhanced atherosclerosis risk prediction in patients referred for cardiac assessment. Rapid plaque quantification had good negative predictive value and high sensitivity alone or in combination with stress testing. FOVUS may serve as a potential point-of-care ultrasound tool in the integrated assessment of cardiac pain.

Keywords: Angiography; Carotid ultrasound; Plaque; Stress test.