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Supplemental material for: Validation of intraluminal filling defect length to identify carotid free-floating thrombus in patients with stroke/TIA

Citation

Torres, Carlos et al. (2022), Supplemental material for: Validation of intraluminal filling defect length to identify carotid free-floating thrombus in patients with stroke/TIA, Dryad, Dataset, https://doi.org/10.5061/dryad.bk3j9kdbq

Abstract

Objective: To validate a previously proposed filling defect length threshold of >3.8 mm on CT-angiography (CTA) to discriminate between free-floating thrombus (FFT) and plaque of atheroma.

Materials and Methods: Prospective multicenter observational study of 100 participants presenting with TIA/stroke symptoms and a carotid intraluminal filling defect on initial CTA.  Follow-up CTA was obtained within one week, and at weeks 2 and 4 if the intraluminal filling defect was unchanged in length.  Resolution or decreased length was diagnostic of FFT, whereas its static appearance after 4 weeks was indicative of plaque. Diagnostic accuracy of FFT length was assessed by receiver operating characteristic analysis.

Results: Ninety-five participants (mean age [standard deviation], 68 [13] years; 61 men; 83 participants with FFT; 12 participants with a plaque) were evaluated. The >3.8 mm threshold had a sensitivity of 88% (73/83) (95% confidence interval {CI}: 78%, 94%) and specificity of 83% (10/12) (95% CI, 51%, 97%) (area under the curve [AUC], 0.91, p<.001) for the diagnosis of FFT. The optimal length threshold was >3.64 mm with a sensitivity of 89%( 74/83) (95% CI, 80%, 95%) and specificity of 83% (10/12) (95% CI, 51%, 97%). Adjusted logistic regression showed that every 1 mm increase in intraluminal filling defect length is associated with an increase in odds of FFT of 4.6 ([95% CI] 1.9-11.1; p=.01).

Conclusion: CTA enables accurate differentiation of FFT versus plaque using craniocaudal length thresholds.

Clinical Trial Identifier: www.clinicaltrials.gov NCT02405845.

Classification of Evidence: This study provides Class I evidence that in patients with TIA/stroke symptoms, the presence of a carotid intraluminal filling defect with length > 3.8 mm on CTA accurately discriminates free-floating thrombus from atheromatous plaque.

Methods

Standard Protocol Approvals, Registration, and Participant Consents: this prospective multicenter observational study was approved by the institutional ethics boards (REB: 20150092-01H; REB:16-391; REB: 15-2456; clinical trial identifier: www.clinicaltrials.gov (NCT02405845). Informed consent was obtained from participants. This study was reported following the guidelines of the Standards for Reporting of Diagnostic Accuracy Studies (STARD).17

Primary Research Question and Classification of Evidence

Primary research question: Can CTA discriminate between free-floating thrombus (FFT) and plaque in patients with stroke/TIA?

This study provides Class I evidence that in patients with TIA/stroke symptoms, the presence of a carotid intraluminal filling defect with length > 3.8 mm on CTA accurately discriminates free-floating thrombus from atheromatous plaque.

Funding

University of Ottawa