Plaques in the descending aorta: A new risk factor for stroke? Visualization of potential embolization pathways by 4D MRI

This meta-analysis has adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for systematic Background and Purpose-Proximal aortic plaques, especially in the aortic arch, have already been established as an important cause of stroke and peripheral embolism. However, aortic plaques situated in the descending thoracic aorta have recently been postulated as a potential embolic source in patients with cryptogenic cerebral infarction through retrograde aortic flow. The aim of the present study was to evaluate the potential association of descending aorta atheromatosis with cerebral ischemia. Methods-We conducted a systematic review and meta-analysis of all available prospective observational studies reporting the prevalence of complex atheromatous plaques in the descending aorta in patients with stroke and in unselected populations undergoing examination with transesophageal echocardiography. Results-We identified 11 eligible studies including a total of 4000 patients (667 patients with stroke and 3333 unselected individuals; mean age, 65 years; 55% men). On baseline transesophageal echocardiograpic examination, the prevalence of complex atheromatous plaques in the descending aorta was higher (P=0.001) in patients with stroke (25.4%; 95% confidence interval, 14.6-40.4%) compared with unselected individuals (6.1%; 95% confidence interval, 3.4-10%). However, no significant difference (P=0.059) in the prevalence of complex atheromatous plaques in the descending aorta was found between patients with cryptogenic (21.8%; 95% confidence interval, 17.5-26.9%) and unclassified (28.3%; 95% confidence interval, 23.9-33.1%) cerebral infarction. Conclusions-Our findings indicate that the presence of complex plaques in the descending aorta is presumably a marker of generalized atherosclerosis and high vascular risk. The present analyses do not provide any further evidence for a direct causal relationship between descending aorta atherosclerosis and cerebral embolism. (Stroke. 2014;45:1764-1770.)

Section: Discussionmentioning

confidence: 99%

Complex Atheromatous Plaques in the Descending Aorta and the Risk of Stroke

Katsanos

Giannopoulos

Kosmidou

et al. 2014

“…11 We included complex aortic plaques in all thoracic locations in our definition of a positive TEE finding because we felt this definition was relevant to clinical practice. Although the evidence that descending aortic atheroma can cause central nervous system events is limited, 22,23 studies addressing prognostic and therapeutic implications of complex aortic atheroma found on TEE after embolic events have included plaques in all thoracic locations. 11,19 -21 Not unexpectedly, no correlation between CIMT and PFO was demonstrated.…”

Section: Discussionmentioning

confidence: 99%

Use of Carotid Intima-Media Thickness to Identify Patients With Ischemic Stroke and Transient Ischemic Attack With Low Yield of Cardiovascular Sources of Embolus on Transesophageal Echocardiography

Ward

Lammertin

Virnich

et al. 2008

Background and Purpose-Carotid intima-media thickness (CIMT) is associated with systemic atherosclerosis and cardioembolic conditions and predicts the risk of recurrent strokes. We sought to establish the relationship between CIMT and cardiovascular sources of embolus (CSE) on transesophageal echocardiography (TEE) and hypothesized that a noninvasive strategy of CIMT assessment and transthoracic echocardiography bubble study would identify patients with ischemic stroke or transient ischemic attack in whom TEE would provide little incremental diagnostic yield. Methods-In 180 patients with ischemic stroke or transient ischemic attack of undetermined origin referred for TEE, we prospectively performed CIMT measurement/plaque screen (Phase 1, nϭ96) or CIMT measurement/plaque screen and transthoracic echocardiography bubble study (Phase 2, nϭ84) before TEE. Phase 1 results were used to construct receiver operating characteristic curves to demonstrate the ability of CIMT to detect CSE on TEE and to identify the optimal CIMT cutoff value for prospective strategy testing (Phase 2). Results-In Phase 1, CIMT was found to correlate with TEE markers of aortic atherosclerosis, including complex aortic plaques, and combined CSE. The optimal CIMT cutoff for detection of CSE on TEE was 0.78 mm. In Phase 2, a positive noninvasive strategy test (CIMT Ն0.78 mm, ϩcarotid plaque, and/or a positive transthoracic echocardiography bubble study) was present in 61%. The prevalence of CSE on TEE was significantly higher among those with a positive compared with a negative noninvasive strategy test (65% versus 9%, PϽ0.001), and this strategy had a sensitivity of 92% and a negative predictive value of 91% for the detection of any CSE on TEE. Conclusion-In patients with stroke or transient ischemic attack of undetermined origin, a noninvasive strategy of CIMT assessment/plaque screen and transthoracic echocardiography bubble study can identify patients in whom further invasive evaluation with TEE will be of low diagnostic yield.

“…10,13 Briefly, plaque localization was based on T1-weighted fat-saturated 3D gradient echo MRI (T1 3D-GRE, spatial resolution 0.8ϫ1.1ϫ1.1 mm 3 ). Further, time-resolved contrast-enhanced MR angiography (CE-MRA) covering the entire thoracic aorta and supra-aortic branches was performed (0.05 mL/kg gadobenate dimeglumine at 3.5 mL/s).…”

Section: Mr Imagingmentioning

confidence: 99%

“…[7][8][9] Specifically, in combination with a novel MRI protocol for 3D aortic plaque detection, the direct interrelation of complex DAo plaques and individual retrograde flow channels was recently demonstrated in 2 patients with embolic stroke. 10 It was the aim of this study to apply this technique in a larger cohort of stroke patients and to investigate the potential role of complex DAo plaques as an embolic source in patients with cryptogenic brain infarction. …”

mentioning

confidence: 99%

Retrograde Embolism From the Descending Aorta

Harloff

Strecker

Dudler

et al. 2009

Self Cite

Background and Purpose-The purpose of this study was to determine the role of plaques Ն4 mm and thrombi (complex plaques) in the descending aorta (DAo) as an embolic high-risk source for stroke. Methods-In 63 acute stroke patients scheduled for TEE, territory and embolic pattern of brain ischemia were prospectively assessed. Multidirectional 3D MRI velocity mapping of the aorta was performed to correlate the extent of retrograde diastolic blood flow with the distance of complex DAo plaques from the left subclavian artery (LSA). Embolic risk from the DAo was present for (1) retrograde flow connecting complex DAo plaques with the LSA, (2) embolic pattern of brain ischemia in a territory supplied by the left vertebral artery, and (3) stroke that could not be explained by other means. Results-33 of 63 patients had complex DAo plaques (distance to LSA 28.1Ϯ29.9 mm). Mean retrograde flow in these subjects was 26.2Ϯ12.3 mm. In 20 of 63 patients (31.7%) retrograde flow connected complex DAo plaques with the LSA. In 4 of these 20 patients (20%) with an embolic stroke in the territory of the brain stem, cerebellum or posterior cerebral artery, etiology could not be explained by other means. Conclusions-Substantial diastolic retrograde flow originating from complex plaques in the descending aorta was detected by multidirectional 3D MRI velocity mapping and constitutes a stroke mechanism that was previously not demonstrable. Key Words: atherosclerosis Ⅲ acute stroke Ⅲ embolic stroke Ⅲ MRI Ⅲ TEE C omplex plaques of the aortic arch with thickness Ն4 mm or containing mobile elements (most often thrombi) or both are considered high-risk sources of brain ischemia. 1 The incidence and thickness of such plaques is highest in the descending aorta (DAo). However, distal to the left subclavian artery they are usually not considered a potential source of stroke because retrograde embolization seems unlikely. [1][2][3] A previous transesophageal echocardiography (TEE) study analyzing the mobility of aortic thrombi in the DAo hypothesized that retrograde cerebral embolism would be theoretically possible especially in case of concomitant aortic valve insufficiency. 4 However, TEE is not able to demonstrate the direct correlation of plaque location and 3D blood flow patterns within the aorta. Accordingly, this stroke mechanism has not yet been systematically investigated.Multidirectional 3D velocity mapping allows the detailed visualization of physiological and pathological 3D blood flow characteristics 5,6 and the analysis of the continuation of flow from the distal aortic arch into the supra-aortic vessels. [7][8][9] Specifically, in combination with a novel MRI protocol for 3D aortic plaque detection, the direct interrelation of complex DAo plaques and individual retrograde flow channels was recently demonstrated in 2 patients with embolic stroke. 10 It was the aim of this study to apply this technique in a larger cohort of stroke patients and to investigate the potential role of complex DAo plaques as an embolic source in patients wit...