Writing in an online Vascular Medicine article, researchers from the Intersocietal Accreditation Commission (IAC) Vascular Testing division report findings from a multicentre study of duplex ultrasound for diagnosis of internal carotid artery (ICA) stenosis.
The study was developed in response to wide variability in the diagnostic criteria used to classify severity of ICA stenosis across vascular laboratories nationwide and following a survey of members of IAC-accredited facilities supporting efforts toward standardisation. The primary objective of the study was to evaluate the widely-used SRU Consensus Criteria (SRUCC) and, if needed, to propose further optimisation to these criteria.
Researchers found that carotid duplex interpretation using SRUCC produced significant overestimation of stenosis for both moderate (50–69%) and severe (>70%) ICA lesions as determined by catheter angiography. The authors conclude that laboratories currently using SRUCC should consider modification of existing criteria to incorporate more stringent and accurate parameters for ICA stenosis greater than 50% by increasing the peak systolic velocity (PSV) threshold to >180cm/sec or requiring the ICA/CCA PSV ratio >2 in addition to PSV of >125cm/sec.
“This study reflects more than six years of work of a team of IAC staff and multispecialty volunteers with case study materials collected from 11 centres [in the USA]. While the SRUCC are broadly used, they had never been formally compared to the gold standard of catheter angiography. We have shown that use of SRUCC overestimated degree of ICA stenosis and identify potential opportunities for modifications that can ultimately enable greater accuracy and consistency in ICA interpretation across vascular laboratories,” said lead investigator, Heather L Gornik (University Hospitals Harrington Heart and Vascular Institute, Cleveland, USA), IAC Vascular Testing Immediate past-president.
“Through its use of real-world data from IAC-accredited vascular laboratories, this paper highlights the opportunity to improve the quality of care for patients with carotid disease,” said Tatjana Rundek (University of Miami Miller School of Medicine, Miami, USA), IAC Vascular Testing president. “By modifying existing criteria to incorporate more accurate parameters and implementing these criteria broadly, the accuracy of diagnostic ultrasound testing can be improved across our vascular community.”
As a next step, IAC Vascular Testing will disseminate a white paper document summarising the study results and providing guidance to vascular laboratories for implementation of criteria and further steps toward standardisation across the vascular testing community.