Differences in diffusion-weighted image and transesophageal echocardiographical findings in cardiogenic, paradoxical and aortogenic brain embolism

Prognosis of ischemic stroke patients with both aortic atheroma and cardioembolic sources

This study aimed to investigate the relationship between complex aortic plaque (CAP) and short-term as well as long-term outcomes following cardioembolic stroke. CAP is a known risk factor for occurrence and recurrence of ischemic stroke. However, the association of CAP on cardioembolic stroke remains unclear. This was retrospective study using prospective cohort of consecutive patients with cardioembolic stroke who underwent transesophageal echocardiography. The functional outcome was evaluated using the modified Rankin Scale score at 3 months, and long-term outcomes were assessed by recurrence of ischemic stroke and occurrence of major adverse cardiovascular events (MACE). Among 759 patients with cardioembolic stroke, 91 (12.0%) had CAP. Early ischemic stroke recurrence within 3 months was associated with CAP (p = 0.025), whereas CAP was not associated with functional outcome at 3 months (odd ratio  1.01, 95% confidence interval [CI]  0.57-1.84, p = 0.973). During a median follow-up of 3.02 years, CAP was significantly associated with ischemic stroke recurrence (hazard ratio = 2.68, 95% CI 1.48-4.88, p = 0.001) and MACE occurrence (hazard ratio = 1.61, 95% CI 1.03-2.51, p = 0.039). In conclusion, CAP was associated with early ischemic stroke recurrence and poor long-term outcomes in patients with cardioembolic stroke. It might be helpful to consider transesophageal echocardiography for patients with cardioembolic stroke to identify CAP.

Imaging Biomarkers and Prevalence of Complex Aortic Plaque in Cryptogenic Stroke: A Systematic Review

BACKGROUND

Complex aortic plaque (CAP) is a potential embolic source in patients with cryptogenic stroke (CS). We review CAP imaging criteria for transesophageal echocardiogram (TEE), computed tomography angiography (CTA), and magnetic resonance imaging and calculate CAP prevalence in patients with acute CS.

METHODS AND RESULTS

PubMed and EMBASE databases were searched up to December 2022 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. Two independent reviewers extracted data on study design, imaging techniques, CAP criteria, and prevalence. The Cochrane Collaboration tool and Guideline for Reporting Reliability and Agreement Studies were used to assess risk of bias and reporting completeness, respectively. From 2293 studies, 45 were reviewed for CAP imaging biomarker criteria in patients with acute CS (N=37 TEE; N=9 CTA; N=6 magnetic resonance imaging). Most studies (74%) used ≥4 mm plaque thickness as the imaging criterion for CAP although ≥1 mm (N=1, CTA), ≥5 mm (N=5, TEE), and ≥6 mm (N=2, CTA) were also reported. Additional features included mobility, ulceration, thrombus, protrusions, and assessment of plaque composition. From 23 prospective studies, CAP was detected in 960 of 2778 patients with CS (0.32 [95% CI, 0.24-0.41], I2=94%). By modality, prevalence estimates were 0.29 (95% CI, 0.20-0.40; I2=95%) for TEE; 0.23 (95% CI, 0.15-0.34; I2=87%) for CTA and 0.22 (95% CI, 0.06-0.54; I2=92%) for magnetic resonance imaging.

CONCLUSIONS

TEE was commonly used to assess CAP in patients with CS. The most common CAP imaging biomarker was ≥4 mm plaque thickness. CAP was observed in one-third of patients with acute CS. However, high study heterogeneity suggests a need for reproducible imaging methods.

Evaluating the Potential Pathology and Short-Term Outcomes of Cryptogenic Stroke Using the Etiological Classification System

AIM

Various embolic sources and pathogenetic mechanisms underlie cryptogenic stroke (CS). We investigated the association of etiological diversity with short-term outcomes in patients with CS using a modified atherosclerosis (A), small-vessel disease (S), cardiac pathology (C), other causes (O), and dissection (D) (ASCOD) system.

METHODS

Patients with CS who underwent transesophageal echocardiography were registered in this multicenter, observational study. In the modified classification system, O and D were inapplicable and thus excluded. Instead, atherosclerosis, small-vessel disease, cardiac pathology-CS classification was specifically constructed for the etiological diagnosis of CS. We utilized this system to explore the mechanism of CS by grading each pathology and evaluated its association with poorer modified Rankin Scale scores of 3-6 at hospital discharge.

RESULTS

A total of 672 patients (68.7±12.8 years, 220 females) were analyzed. In the multiple logistic regression model, female sex (odds ratio [OR], 1.87 [1.15-3.04]; P=0.012), body mass index (OR, 0.93 [0.88-0.99]; P=0.025), National Institute of Health Stroke Scale score (OR, 1.16 [1.12-1.21]; P＜0.001), CHADS2 score (OR, 1.56 [1.30-1.86]; P＜0.001), D-dimer (OR, 1.04 [1.01-1.08]; P=0.015), diffusion-weighted image (DWI) lesion size (OR, 1.44 [1.10-1.89]; P=0.009), and S＋C score (OR, 1.26 [1.03-1.56]; P=0.029) were associated with poor functional outcome at discharge whereas the S＋C score was marginally associated with poor functional outcome after excluding 137 patients with a premorbid modified Rankin Scale score of ≥ 3.

CONCLUSIONS

The coexistence of small-vessel disease and cardiac pathology might be associated with poor in-hospital functional outcome in CS.

Coexisting of aortic arch atheroma and atrial fibrillation for short-term recurrence and poor functional outcome in acute stroke

BACKGROUND AND PURPOSE

Multiple embolic sources are sometimes observed simultaneously in patients with embolic stroke. The present study investigated the effects of coexisting aortic arch atheroma ≥ 4 mm thick and atrial fibrillation (AF) on short-term stroke recurrence and functional outcome.

METHODS

Transesophageal echocardiography (TEE) was performed in consecutive embolic stroke patients, and 395 patients were classified into 4 groups according to the presence of aortic arch atheroma ≥ 4 mm thick and AF: AF - /ARCH - group, AF + /ARCH - group, AF - /ARCH + group, and AF + /ARCH + group. In accordance with these 4 groups, we evaluated stroke recurrence and all-cause death for 3 months after stroke onset, and also evaluated the 3-month functional outcome using the modified Rankin scale (mRS).

RESULTS

Among the 128 AF patients, 39.1% also had aortic arch atheroma ≥ 4 mm thick. Of the 395 enrolled cases, the AF + /ARCH + group showed the highest frequencies of stroke recurrence and all-cause death during 3 months after onset. On multivariate analysis, stroke recurrence or all-cause death during 3 months after onset was relatively more frequent in the AF + /ARCH + group than in the AF + /ARCH - group (OR, 2.34; 95% CI, 0.82-6.69; p = 0.11), but that was not statistically significant, and poor functional outcome (mRS score 3-6) at 3 months was significantly more frequent in the AF + /ARCH + group than in the AF + /ARCH - group (OR, 2.59; 95% CI, 1.08-6.24; p = 0.0339).

CONCLUSIONS

Aortic arch atheroma concomitant with AF is not rare and appears associated with increased risks of stroke recurrence and poor functional outcome.

Ability of the number of territories involved on DWI-MRI to predict occult systemic malignancy in cryptogenic stroke patients

BACKGROUND

Lesions in multiple arterial territories is one of the typical features of malignancy patients with cryptogenic stroke. Hence, if patients with cryptogenic stroke display such feature, occult cancer could be predicted. The study aimed to analyze the predictive ability of the number of territories involved on DWI-MRI for occult systemic malignancy (OSM) in patients with cryptogenic stroke.

METHODS

We enrolled patients with cryptogenic stroke without a diagnosis of malignancy at stroke onset between January 2013 and November 2018. Clinical variables were analyzed between cryptogenic stroke patients with and without OSM through univariate and multiple logistic regression analyses. Points for OSM were generated by β-coefficients. The sensitivity and specificity of the risk score were assessed by the area under the receiver operating characteristic curve (AUROC). The cutoff value for predicting OSM was determined by the maximum Youden index.

RESULTS

Among 108 cyptogenic stroke patients, compared to patients without OSM (n = 96), patients with OSM (n = 12) had a lower nutrition status (P = 0.031), higher plasma D-dimer levels (P < 0.001) and more territories involved on DWI-MRI (P < 0.001). Multiple logistic regression analysis revealed that plasma D-dimer levels (OR, 3.54; 95% Cl, 1.62-7.76; P = 0.002) and the number of territories involved (OR, 4.45; 95% CI, 1.25-15.80; P = 0.021) independently predicted OSM. The predictive score system built upon the number of territories showed good discrimination with an AUROC of 0.84 (95% CI, 0.71-0.96). The cutoff value was 2 with a maximum Youden's index of 0.56, which means that patients with more than one territory involved on DWI-MRI may need extensive screening for OSM.

CONCLUSIONS

The number of territories involved on DWI-MRI was a valid predictor for OSM in cryptogenic stroke patients who need to undergo further evaluations .

Diffusion-weighted imaging-documented bilateral small embolic stroke involving multiple vascular territories may indicate occult cancer: A retrospective case series and a brief review of the literature

Diffusion-weighted imaging (DWI) MRI is very sensitive for detecting small embolic brain infarctions. Stroke as the first manifestation of cancer is extremely rare. We performed a retrospective study to identify the clinical and DWI features of patients with acute ischemic stroke as the first manifestation of occult cancer. A total of five patients in our hospital from January 2017 to May 2019 were analyzed. We also reviewed the literature and seven case series (16 patients) were included. Most of these patients were aged in their sixties and lung cancer was the most common type of occult cancer. Patients showed various presentations of ischemic stroke. All of the patients showed small multiple lesions on DWI that involved mostly the anterior or both anterior and posterior territories. The lesions were mostly in both the supratentorium and infratentorium, with the mechanisms of embolic and watershed infarcts. These features were useful for identifying the causes of embolic stroke. Therefore, patients with small bilateral embolic stroke, especially those involved in multiple vascular territories, should be examined for concealed malignancy.

Association of Left Atrial Enlargement with Cortical Infarction in Subjects with Patent Foramen Ovale

Background and Purpose

Left atrial dysfunction has been reported in patients with patent foramen ovale (PFO). Here we investigated the role of left atrial dysfunction in the development of embolic stroke in patients with PFO.

Methods

We identified consecutive patients with embolic stroke of undetermined sources except for PFO (PFO+ESUS). Healthy subjects with PFO served as controls (PFO+control). A stratified analysis by 10-year age group and an age- and sex- matching analysis were performed to compare echocardiographic markers between groups. In the PFO+ESUS group, infarct patterns of PFO-related stroke were determined (cortical vs. cortico-subcortical) and analyzed in correlation with left atrial function parameters.

Results

A total of 118 patients and 231 controls were included. The left atrial volume indices (LAVIs) of the PFO+ESUS patients were higher than those of the PFO+controls in age groups of 40–49, 50–59, and 60–69 years (P<0.001, P=0.003, and P=0.027, respectively), and in the age- and sex-matched analysis (P=0.001). In the PFO+ESUS patients, a higher (>28 mL/m²) LAVI was more associated with the cortical infarct pattern (P=0.043 for an acute infarction and P=0.024 for a chronic infarction, both adjusted for age and shunt amount). The degree of right-to-left shunting was not associated with infarct patterns, but with the posterior location of acute infarcts (P=0.028).

Conclusions

Left atrial enlargement was associated with embolic stroke in subjects with PFO. Left atrial physiology might contribute to the development of PFO-related stroke and need to be taken into consideration for optimal prevention of PFO-related stroke.

[Two cases of ischemic cerebrovascular disease with only memory disturbance as neurological symptom and abnormal MR findings]

Case 1 involved a 77-year-old man admitted to our hospital after he lost almost all memory of work on the day before. Diffusion-weighted imaging (DWI) revealed spotty hyperintensities in the bilateral hippocampi, which were considered responsible for the amnesia. Transesophageal echocardiography (TEE) showed severe aortic arch atheroma, 6.8 mm in diameter with extension to the branch. Aortogenic embolism to the bilateral hippocampi was diagnosed. Case 2 involved a 66-year-old woman admitted to our hospital because she had lost all memory of the 5 hours she was out. She had transient anterograde amnesia. DWI revealed no ischemic lesions, but magnetic resonance angiography (MRA) revealed branch occlusion of the right posterior cerebral artery. MRA on hospital day 7 revealed partial recanalization. TEE showed aortic arch atheroma of 3.9 mm in diameter with extension to the branch. In both cases, aortogenic embolism to the hippocampus might have been causally related to transient memory disturbance. In patients with acute memory disturbance, the possibility of ischemic stroke should be considered.

Contributing Mechanisms of Aortic Atheroma in Ischemic Cerebrovascular Disease

In recent years, the correlation between aortic atheroma (AA) and the occurrence and recurrence of ischemic cerebrovascular disease (ICVD) has attracted much attention, but the contributory mechanisms remain controversial. This review analyzes related research on the roles of AA in ICVD, and demonstrates the correlation between the formation and development of AA and abnormal metabolism, inflammation, hemodynamic changes, and other contributory factors. The presence of complex aortic plaque (CAP) in the ascending aorta and aortic arch increases the risk of cerebral embolism and degree of injury, while the association between CAP in the descending aorta and cerebral embolism remains ambiguous. AA also functions as an indicator of atherosclerosis burden as well as hypercoagulability, which may further increase the risk of ICVD. Further study on the relationship of AA to ICVD will improve diagnosis and treatment in clinical practice.

Aortic arch atherosclerosis in ischaemic stroke of unknown origin affects prognosis

Background

Cerebral infarction of unknown origin at admission accounts for half of all cerebral infarction cases in some institutions. However, the factors associated with cerebral infarction prognosis have not been sufficiently examined. Here, we investigated whether aortic arch plaques (AAPs) on transoesophageal echocardiography (TOE) were associated with the prognosis of cerebral infarction of unknown origin at admission.

Methods

Of 571 patients who were hospitalised between June 2009 and September 2011, 149 (age: 67 ± 14 years; 95 men) with cerebral infarctions of unknown origin at admission underwent TOE and were enrolled in this study. We examined their clinical characteristics, the incidence of intermittent atrial fibrillation detected on 24-hour electrocardiography, and the echographic findings of the carotid artery in the hospital. A poor prognostic outcome was defined as a modified Rankin Scale score of ≥3 after 90 days.

Results

In all, 110 patients (74%) showed good prognoses and 39 patients (26%) showed poor outcomes. A National Institutes of Health Stroke Scale score of >6 on admission [odds ratio (OR) = 6.77; 95% confidence interval (CI): 2.59-18.8; p < 0.001] and AAPs of ≥4 mm (OR = 2.75; 95% CI: 1.19-6.91; p = 0.024) showed significant associations with a poor prognosis of cerebral infarction of unknown origin at admission.

Conclusions

Thick AAPs could be a factor in the prediction of a poor prognosis of cerebral infarction of unknown origin at admission. The establishment of international standards for aortogenic brain embolisms is required. Future prospective studies should examine cerebral infarctions of unknown origin.

Clues to occult cancer in patients with ischemic stroke

Background

We hypothesized that hidden malignancy could be detected in patients with cryptogenic stroke without active cancer when they showed the distinctive characteristics of cancer-related stroke.

Methods and Findings

Among 2,562 consecutive patients with acute ischemic stroke, patients with cryptogenic stroke were analyzed and categorized into two groups according to the presence of active cancer: cryptogenic stroke with active cancer (cancer-related stroke, CA-stroke) group and without active cancer (CR-stroke) group. Patients with active lung cancer without stroke were also recruited for comparison purposes (CA-control). Clinical factors, lesion patterns on diffusion-weighted MRI (DWI), and laboratory findings were analyzed among groups. A total of 348 patients with cryptogenic stroke were enrolled in this study. Among them, 71 (20.4%) patients had active cancer at the time of stroke. The D-dimer levels were significantly higher in patients with CA-stroke than those with CR-stroke or CA-control (both p<0.001). Regarding lesion patterns, patients with CA-stroke mostly had multiple lesions in multiple vascular territories, while more than 80% of patients with CR-stroke had single/multiple lesions in a single vascular territory (P<0.001). D-dimer levels (OR 1.11 per 1 µg/mL increase; 95% CI 1.06–1.15; P<0.001) and DWI lesion patterns (OR 7.13; 95% CI 3.42–14.87; P<0.001) were independently associated with CA-stroke. Workup for hidden malignancy was performed during hospitalization in 10 patients who showed elevated D-dimer levels and multiple infarcts involving multiple vascular territories but had no known cancer, and it revealed hidden malignancies in all the patients.

Conclusion

Patients with CA-stroke have distinctive D-dimer levels and lesion patterns. These characteristics can serve as clues to occult cancer in patients with cryptogenic stroke.

Patent foramen ovale and atrial septal aneurysm can cause ischemic stroke in patients with antiphospholipid syndrome

The purpose of the present study was to evaluate the contributions of embolic etiologies, patent foramen ovale (PFO) and atrial septal aneurysm (ASA) to the pathogenesis of ischemic stroke in patients with antiphospholipid syndrome (APS). We performed transesophageal echocardiography (TEE) examination for consecutive stroke patients who had been diagnosed with APS (APS group) to detect potential embolic sources. APS was diagnosed based on the modified Sapporo criteria. The control stroke group comprised age- and sex-matched cryptogenic stroke patients undergoing TEE. We assessed and compared the clinical characteristics and TEE findings between stroke patients with APS and control stroke groups. Among 582 patients, nine patients (nine women; mean age, 50 ± 18 years) were classified into the APS group. In 137 patients undergoing TEE, 41 age-matched female stroke patients were recruited to the control stroke group. Prevalences of PFO and ASA were significantly higher in the APS group than in the control stroke group (89 vs. 41 %, p = 0.027; 67 vs. 20 %, p = 0.015, respectively). Multiple logistic regression analysis showed that PFO (odds ratio (OR), 13.71; 95 % confidence interval (CI), 1.01-185.62; p = 0.049) and ASA (OR, 8.06; 95 % CI, 1.17-55.59; p = 0.034) were independently associated with the APS group. PFO and ASA were strongly associated with the APS group, and could thus represent potential embolic sources in ischemic stroke patients with APS.

Characterization of the infarct pattern caused by vulnerable aortic arch atheroma: DWI and multidetector row CT study

BACKGROUND

Aortic arch atheroma (AAA) has been accepted as a possible embolic source in patients with ischemic stroke, especially cryptogenic stroke. However, despite its well-known role as a risk factor for stroke, research focused on the mechanism or characteristics of stroke caused by AAA is insufficient. In this study, we aimed to evaluate clinical and radiological characteristics including lesion pattern on DWI in acute stroke patients associated with vulnerable AAA detected by multidetector row computed tomography (MDCT).

METHODS

From September 2008 through May 2011, patients who presented with acute ischemic stroke and underwent MDCT were found in a prospective stroke registry. Patients without evident stroke etiology were included and classified by presence of vulnerable AAA. Vulnerable AAA was defined as (i) at least 6 mm thick adjacent to the aortic wall; (ii) ulcerated plaque, or (iii) soft plaque. Soft plaque was defined as the presence of clearly visualized area of hypoattenuation (<80 Hounsfield units) suggestive of thrombus. The patients without vulnerable AAA were classified as no/simple AAA group. The characteristics of diffusion-weighted MRI (DWI) lesions were analyzed in terms of the number and size of the lesions, and the involved vascular territories.

RESULTS

A total of 63 cryptogenic stroke patients were included in this study. Vulnerable AAA was observed in 15 (23.8%) patients. The patients with vulnerable AAA were older than those with no/simple AAA (p = 0.026). DWI analysis revealed that the vulnerable AAA group had a greater chance of having multiple and small lesions in multiple vascular territories that were mainly located in cortical and border-zone regions than the no/simple AAA group. Multiple logistic regression analysis showed that age (odds ratio 1.17; 95% confidence interval 1.02-1.34) and multiple small lesions in multiple vascular territories (odds ratio 33.18; 95% confidence interval 4.26-258.45) were independently associated with vulnerable AAA.

CONCLUSION

Vulnerable AAA is independently associated with a DWI pattern characterized by multiple small scattered lesions in multiple vascular territories in conjunction with age. It may help determine stroke mechanism quickly and easily, and provide more information about the pathomechanism of vulnerable AAA-related stroke.