CT Angiography of the Aorta Is Superior to Transesophageal Echocardiography for Determining Stroke Subtypes in Patients with Cryptogenic Ischemic Stroke

Abstract

Background: The etiology of ischemic strokes remains cryptogenic in about one third of patients, even after extensive workup in specialized centers. Atherosclerotic plaques in the aorta can cause thromboembolic events but are often overlooked. They can elude standard identification by transesophageal echocardiography (TEE), which is invasive or at best uncomfortable for many patients. CT angiography (CTA) can be used as an alternative or in addition to TEE if this technique fails to visualize every part of the aorta and in particular the aortic arch. Methods: We prospectively studied 64 patients (47 men, age 60 ± 13 years) classified as having cryptogenic stroke after standard and full workup [including brain MRI and 24-hour electrocardiogram (ECG)] with ECG-triggered CTA of the aorta in search of plaques and compared the results with those of TEE. Investigators were blinded to the results of both techniques. Plaques were graded on CTA according to their presence (0 = not present; 1 = mild; 2 = severe) and degree of calcification (1a or 2a = noncalcified; 1b or 2b = calcified). Associations with risk factors and infarct localization were also assessed. Results: Only 21 of 64 patients (32.8%) had aortic plaques identified by TEE, compared to 43 of 64 (67.2%) with CTA (p < 0.05). The plaque localization was as follows (TEE vs. CTA): ascending aorta, 10 vs. 20 (p < 0.05); aortic arch, 10 vs. 40 (p < 0.05), and descending aorta, 20 vs. 34 (p < 0.05). Grade 1 plaques were most commonly found in the aortic arch (25; 39%), while grade 2 plaques were most often detected in the aortic arch (15; 23.4%) and the descending aorta (14; 21.9%). There was no significant correlation between plaque location, infarct territory or vascular risk profile, except for hypertension (p = 0.003), which was significantly associated with the presence of plaques. Conclusions: CTA identifies more plaques throughout the aortic arch and around the origins of the major cerebral arteries in particular compared to TEE. These may represent potential embolic sources of acute ischemic stroke. Better plaque detection may have an impact on the best available secondary prevention regimen in individual patients if proximal embolic sources are suspected.

Coexisting Large and Small Vessel Disease in Patients with Ischemic Stroke of Undetermined Cause

“…Although the strokes cannot be classified into one etiological category with high evidence, these diseases (as well as vascular risk factors) are present, which is reflected in the ASCO score. Significant aortic plaques are also common (76.1%) in this patient group, confirming recent observations [4,7]. …”

Computed Tomography and Echocardiography together Reveal More High-Risk Findings than Echocardiography Alone in the Diagnostics of Stroke Etiology

“…Indeed, after echocardiography, only 9 high-risk findings in 140 patients were found and this number rose to 25 high-risk findings after performing both echocardiography and CT. This increasing sensitivity helps to identify a subtype of stroke and it reduces the number of patients with cryptogenic stroke that has shown to be relatively high in stroke registries [14,15,16]. The main explanation for the increasing sensitivity was the higher number of previous myocardial infarctions found by CACC-CT but also ventricular thrombus and aortic thrombus, and more aortic arch atheromatous plaque were found after CACC-CT evaluation.…”

“…Thirdly, to further characterize the reliability of new imaging methods reported here, intra- and interobserver consistency in data interpretation have to be studied. Considering the methodological differences between CT (whole aorta and LV coverage) and echocardiography (visualization limited to acoustic windows), CT has the potential not only to improve determination of stroke subtypes, as found in a recent study focusing on aortoembolic stroke [15], but also to improve the repeatability of data interpretation, the Achilles heel of echocardiography. …”

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

“…The remaining 11 studies were included both in qualitative and in quantitative synthesis ( Figure 1). [13][14][15][16][17][18][19][20][21][22][23] The characteristics of included studies are summarized in Table 1.…”