Atherosclerotic Aortic Arch Plaques in Cryptogenic Stroke: A Microembolic Signal Monitoring Study

Abstract

Background and Purpose: To find out the prevalence of relevant atherosclerotic plaques in the aortic arch and their potential role as a source of embolism in cryptogenic stroke. Methods: We performed a transoesophageal echocardiography (TEE) on 49 patients with cryptogenic stroke from a total series of 212 non-selected patients with acute ischaemic stroke studied prospectively by cranial computed tomography (CT), colour-duplex and transcranial Doppler (TCD) sonography with micro-embolic signal (MES) monitoring. Cryptogenic stroke was diagnosed in those patients without carotid or intracranial stenosis >50%, nor lacunar or cardio-embolic strokes. We defined relevant plaques as those ≧4 mm thick located in the ascending aorta or proximal arch. Results: Twenty-three patients (46.9%) had atherosclerotic aortic plaques (AAP): 3 in the ascending aorta (in 1 ≧4 mm), 11 in the proximal aortic arch (in 4 ≧4 mm) and 9 in the descending aorta (in 5 ≧4 mm). Hence, 5 patients (10.2%) had relevant plaques. Aortic plaques were significantly related to older age (p < 0.001) and male gender (p = 0.042). A carotid artery stenosis <50% was found in 39% of patients with AAP and in 8% of those without AAP (p = 0.009). MES were detected in 3 patients with plaques ≧4 mm thick, but not in those without AAP or with AAP <4 mm thick (p = 0.006). Conclusion: Although few patients with cryptogenic stroke had relevant plaques in our non-selected population, our results support the hypothesis that relevant aortic plaques have embolic potential.

Evaluation of Cryptogenic Stroke With Advanced Diagnostic Techniques

“…32,38,41,43 In addition, blood biomarkers, such as high pro-brain natriuretic peptide levels, may be predictors for incident AF in patients with cryptogenic stroke. [71][72][73] Aortogenic Embolic Source Evaluation TCD microembolism study showed that AAA has embolic potential, 74 and DWI patterns are characterized by multiple small scattered lesions in multiple vascular territories that are mainly located in cortical and borderzone regions. 75 These are in line with an autopsy study of cases with cerebral atheromatous embolism, which showed that atheromatous emboli containing mostly cholesterol crystals are associated with borderzone infarct, whereas large emboli containing fibrin are associated with large territory infarcts.…”

Moderate Atheroma of the Aortic Arch and the Risk of Stroke

“…These results suggest that aortic atheroma of 3.5 mm or more may be a direct source of thromboemboli. Several studies using transcranial Doppler showed that embolic signals in the middle cerebral artery can be more frequently detected in patients with severe arch atheroma than in those without severe arch atheroma [19,20,21]. Severe atheroma along the aortic arch, therefore, can be a source of cerebral emboli.…”

Cerebral Microembolism Is Blocked by Tirofiban, a Selective Nonpeptide Platelet Glycoprotein IIb/IIIa Receptor Antagonist

“…[3][4][5][6] Circumstantial evidence suggests that cerebral microemboli originate from the ulcerated arterial plaque. [7][8][9][10][11] Activated platelets play a crucial role in the generation of embolic events. Irrespective of the activating stimulus, the resulting platelet aggregation is mediated by glycoprotein IIb/IIIa (GPIIb/IIIa) receptors.…”