In:
Cerebrovascular Diseases, S. Karger AG, Vol. 43, No. 3-4 ( 2017), p. 132-138
Abstract:
〈 b 〉 〈 i 〉 Background: 〈 /i 〉 〈 /b 〉 Retrograde brain embolization from complex plaques of the proximal descending aorta (DAo) has been identified as a new potential mechanism of stroke. Our purpose was to identify predictors of increased retrograde aortic blood flow indicating an elevated risk of brain embolization from the DAo. 〈 b 〉 〈 i 〉 Methods: 〈 /i 〉 〈 /b 〉 A total of 485 patients with acute ischemic stroke were prospectively included and underwent transesophageal echocardiography. Blood flow velocities in the proximal DAo were studied using 2D pulse-wave Doppler ultrasound. Velocity-time integrals (VTI) were calculated for antegrade and retrograde velocity directions. The ratio (VTI 〈 sub 〉 retrograde 〈 /sub 〉 /VTI 〈 sub 〉 antegrade 〈 /sub 〉 ) was used to estimate retrograde flow extent. Associations between patient demographics, cardiovascular risk factors, echocardiographic parameters, and VTI 〈 sub 〉 ratio 〈 /sub 〉 were analyzed using multivariate linear regression. 〈 b 〉 〈 i 〉 Results: 〈 /i 〉 〈 /b 〉 Retrograde blood flow in the DAo occurred in all patients. Velocity profiles in the proximal DAo were as follows (mean ± SD): VTI 〈 sub 〉 antegrade 〈 /sub 〉 = 21.1 ± 6.5, VTI 〈 sub 〉 retrograde 〈 /sub 〉 = 11.0 ± 3.6, and VTI 〈 sub 〉 ratio 〈 /sub 〉 = 0.54 ± 0.16. Diameter ( 〈 i 〉 r 〈 /i 〉 = 0.25, 〈 i 〉 p 〈 〈 /i 〉 0.001), presence of complex plaques ( 〈 i 〉 r 〈 /i 〉 = 0.12, 〈 i 〉 p 〈 /i 〉 = 0.007), and reduced strain of the DAo ( 〈 i 〉 r 〈 /i 〉 = -0.23, 〈 i 〉 p 〈 〈 /i 〉 0.001) had significant partial effects in a predictor model based on predefined variables, which predicted 26% (adjusted 〈 i 〉 R 〈 /i 〉 〈 sup 〉 2 〈 /sup 〉 = 0.26) of the variance in VTI 〈 sub 〉 ratio 〈 /sub 〉 . A unit increase in the DAo diameter was associated with a 2% increase in VTI 〈 sub 〉 ratio 〈 /sub 〉 (95% CI 1-2.8%, 〈 i 〉 p 〈 〈 /i 〉 0.001). Presence of complex plaques increased VTI 〈 sub 〉 ratio 〈 /sub 〉 by 7% (95% CI 2-13%, 〈 i 〉 p 〈 /i 〉 = 0.007) and an increase in strain by 0.1 indicated a decrease in VTI 〈 sub 〉 ratio 〈 /sub 〉 by about 11% (95% CI 6.2-15.5%, 〈 i 〉 p 〈 /i 〉 〈 0.001). Complex atheroma was found in the proximal DAo of 79 subjects, of which 40 (50.6%) had a VTI 〈 sub 〉 ratio 〈 /sub 〉 above average (VTI 〈 sub 〉 ratio 〈 /sub 〉 ≥0.54) compared to 87 of 261 (33.3%) patients without any complex plaques ( 〈 i 〉 p 〈 〈 /i 〉 0.001). Twenty-five of 79 (31.7%) patients with complex DAo plaques had a VTI 〈 sub 〉 ratio 〈 /sub 〉 ≥0.60, which indicates a high likelihood of retrograde pathline length of ≥3 cm and thus increased risk of retrograde cerebral embolization. Stroke etiology of those 25 patients was determined in 13 and cryptogenic in 12 cases. 〈 b 〉 〈 i 〉 Conclusions: 〈 /i 〉 〈 /b 〉 Retrograde blood flow in the DAo was found in all stroke patients. However, it increased further in patients with concomitant complex plaques, low strain, and/or large aortic diameter, that is, in those with atherosclerosis of the DAo. Accordingly, such patients may be predisposed to retrograde embolization in case of occurrence of a complex plaque in proximity to a brain-supplying artery.
Type of Medium:
Online Resource
ISSN:
1015-9770
,
1421-9786
Language:
English
Publisher:
S. Karger AG
Publication Date:
2017
detail.hit.zdb_id:
1482069-9
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