Supplementary Material for: A Novel Evaluation for Predicting Aortic Complicated Lesions Using Calcification on Chest X-ray

Background: The aorta is a significant source of
cerebral thromboembolisms. Aortic complicated lesions (ACLs) are key
findings on transesophageal echocardiography (TEE) for assessing aortic
sources of emboli to the brain. TEE is sometimes avoided due to its
invasiveness. However, few reports have examined alternative methods for
predicting ACLs. We investigated relationships between aortic arch
calcification (AAC) on chest X-ray and ACLs. Methods:
Participants comprised 300 patients with acute ischemic stroke or
transient ischemic attack who underwent TEE for the evaluation of the
aortic arch and heart. A postero-anterior plain chest X-ray in the
recumbent position was evaluated on admission for each patient. AAC was
evaluated using 4 grades (0-3) and “AAC thickness” defined as the
distance from the inner margin of the most distant AAC to the outer
margin of the aortic vessel wall. ACLs were defined by intima-media
thickness (IMT) ≥4.0 mm or presence of ulcerated or mobile plaques.
Carotid maximum IMT on ultrasonography was also evaluated. Comparison of
the diagnostic ability to predict ACL was performed between AAC grades
and AAC thickness or AAC thickness and carotid maximum IMT using the
Delong method. Results: ACLs were identified in 71
patients (23.7%), including ACLs with ulcerated plaques in 24 (8.0%) and
ACLs with mobile plaques in 9 (3.0%). Plaque thickness was greater in
higher AAC grades or higher quartiles of AAC thickness (p for
trend <0.001 each). The Cochran-Armitage test showed that both higher
AAC grade and higher quartile of AAC thickness were significantly
associated with the presence of ACLs, as well as the presence of
ulcerated or mobile plaques (p for trend < 0.001 each).
Receiver-operating characteristic (ROC) analysis showed optimal cut-off
values for AAC thickness of 5.6 mm for ACLs and 6.0 mm for ulcerated or
mobile plaques. Multivariate logistic regression revealed a higher grade
of AAC (grades 2-3) and AAC thickness (≥6 mm) as significantly
associated with ACLs and ulcerated or mobile plaques (p < 0.001 each). ROC curve comparisons showed that AAC thickness offered a better marker of ACLs than AAC grade (p = 0.019), although no significant difference was evident between AAC thickness and carotid maximum IMT (p = 0.567). Conclusions:
AAC on chest X-ray, evaluated by both AAC grade and AAC thickness to
the outer aortic vessel wall, was significantly associated with ACLs on
TEE. AAC thickness was suggested as more useful than AAC grade and
equivalent to carotid IMT in predicting ACLs.