The use of vascular ultrasound as an initial diagnostic test is the strongest independent predictor for giant cell arteritis (GCA) and it may effectively replace temporal artery biopsy, according to study results published in The Lancet Rheumatology.
In the current study, the researchers sought to evaluate the diagnostic accuracy of ultrasound examination in patients with suspected GCA.
The multicenter, prospective, noninterventional Evaluation of Ultrasound’s Role in Patients Suspected of Having Extracranial and Cranial Giant Cell Arteritis (EUREKA) cohort study was conducted at 3 Danish hospitals. Individuals aged 50 years and older with suspected GCA were enrolled. Participants underwent a bilateral ultrasound of the facial arteries, common carotid arteries, axillary arteries, and the 3 branches of the temporal arteries (ie, common superficial artery, parietal, and frontal branches). A temporal biopsy was also performed within 7 days of initiation of corticosteroid therapy.
From April 2014 and July 2017, a total of 118 individuals were screened, of whom 106 had both ultrasound examinations and a temporal artery biopsy and were included in the intention-to-diagnose population. The mean participant age was 72.7±7.9 years; 59% were women.
Study results showed that the temporal lobe biopsy was positive in 43% (n=46/106) of the participants, with 58% (n=62/106) of the patients having a clinically confirmed diagnosis of GCA at 6 months (temporal artery biopsy sensitivity, 74%; 95% CI, 62%-84%; temporal artery biopsy specificity, 100%; 95% CI, 92%-100%).
Further, cranial artery ultrasound was positive in all participants with a positive temporal artery biopsy. Overall, 58% (n=7/12) of the patients with a positive ultrasound result and a negative temporal artery biopsy were confirmed as having large-vessel GCA with the use of other imaging procedures. Ultrasound diagnosis of GCA had a sensitivity of 94% (95% CI, 84%-98%) and a specificity of 84% (95% CI, 70%-93%).
According to logistic regression analysis, the use of ultrasound was the strongest baseline predictor of a clinically confirmed diagnosis of GCA at 6 months (odds ratio [OR], 76.0; 95% CI, 21.0-280.0; P <.0001). After adjustments for sex and age, the OR was 141.0 (95% CI, 27.0-743.0; P <.0001).
Study limitations included ultrasound diagnosis being confirmed by an investigator not masked to the clinical data; the final diagnosis was based on ultrasound results; and temporal artery biopsy was not conducted among all patients.
The researchers concluded, “Vascular ultrasound of cranial arteries and large vessels by trained ultrasonographers using high-end equipment and [optimized] settings have high diagnostic sensitivity and specificity in patients with suspected [GCA], and it might replace invasive temporal artery biopsy as a first-line diagnostic method.”
They added, “In the future, implementation studies might be needed to test the applicability of these methods to health care internationally.”
Chrysidis S, Møller Døhn U, Terslev L, et al. Diagnostic accuracy of vascular ultrasound in patients with suspected giant cell arteritis (EUREKA): a prospective, multicenter, non-interventional, cohort study. Lancet Rheumatol. Published online October 26, 2021. doi:10.1016/S2665-9913(21)00246-0