Complex plaques in the proximal descending aorta: an underestimated embolic source of stroke
Andreas Harloff1, Jan Simon, Stefanie Brendecke
1University Hospital Freiburg, Department of Neurology, Breisacher Strasse 64, 79106 Freiburg, Germany. andreas.harloff@uniklinik-freiburg.de
Insights
Retrograde flow from complex descending aorta (DAo) plaques is common in stroke patients and can cause embolism. These aortic plaques are a newly identified source of stroke, impacting both determined and cryptogenic cases.
Area of Science:
- Cardiovascular Imaging
- Neurology
- Vascular Medicine
Background:
- Complex plaques in the descending aorta (DAo) are increasingly recognized.
- Their role in embolic stroke etiology requires further investigation.
Purpose of the Study:
- To determine the incidence of retrograde flow from complex DAo plaques.
- To assess the potential of this retrograde flow to cause embolic stroke.
Main Methods:
- Prospective inclusion of 94 acute stroke patients with DAo plaques (≥3 mm).
- Utilized transesophageal echocardiography and MRI for plaque characterization and 3D blood flow analysis.
- Evaluated retrograde flow connection between plaque location and supra-aortic arteries.
Main Results:
- Retrograde flow from complex DAo plaques reached supra-aortic vessels in a significant proportion of patients (58.5% to left subclavian artery).
- Potential embolization from DAo plaques was identified in 33.3% of determined stroke and 24.3% of cryptogenic stroke cases.
- Decreasing heart rate correlated with increased flow reversal to the aortic arch.
Conclusions:
- Retrograde flow from complex DAo plaques is a frequent finding in stroke patients.
- This flow pattern can explain embolism to all cerebral territories.
- Complex DAo plaques represent a novel and significant source of embolic stroke.
Background And Purpose:
To investigate the incidence of retrograde flow from complex plaques (> or =4-mm-thick, ulcerated, or superimposed thrombi) of the descending aorta (DAo) and its potential role in embolic stroke.
Methods:
Ninety-four consecutive acute stroke patients with aortic plaques > or =3-mm-thick in transesophageal echocardiography were prospectively included. MRI was performed to localize complex plaques and to measure time-resolved 3-dimensional blood flow within the aorta. Three-dimensional visualization was used to evaluate if diastolic retrograde flow connected plaque location with the outlet of the left subclavian artery, left common carotid artery, or brachiocephalic trunk. Complex DAo plaques were considered an embolic source if retrograde flow reached a supra-aortic vessel that supplied the territory of visible acute and embolic retinal or cerebral infarction.
Results:
Only decreasing heart rate was correlated (P<0.02) with increasing flow reversal to the aortic arch. Retrograde flow from complex DAo plaques reached the left subclavian artery in 55 (58.5%), the left common carotid artery in 23 (24.5%), and the brachiocephalic trunk in 13 patients (13.8%). Based on routine diagnostics and MRI of the ascending aorta/aortic arch, stroke etiology was determined in 57 and cryptogenic in 37 patients. Potential embolization from DAo plaques was then identified in 19 of 57 patients (33.3%) with determined and in 9 of 37 patients (24.3%) with cryptogenic stroke.
Conclusions:
Retrograde flow from complex DAo plaques was frequent in both determined and cryptogenic stroke and could explain embolism to all brain territories. These findings suggest that complex DAo plaques should be considered a new source of stroke.
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