Cardioembolic Stroke

Association Between Ischemic Stroke Subtype and Stroke Severity: The Atherosclerosis Risk in Communities Study

BACKGROUND AND OBJECTIVES

Disability after stroke occurs across ischemic stroke subtypes, with a suggestion that embolic strokes are more devastating. Whether this difference is as a result of differences in comorbidities or differences in severity at the time of the stroke event is not known. The primary hypothesis was that participants with embolic stroke would have more severe stroke at the time of admission and a higher risk of mortality, compared with thrombotic stroke participants even with consideration of confounders over time, with a secondary hypothesis that this association would differ by race and sex.

METHODS

Atherosclerosis Risk in Communities (ARIC) study participants with incident adjudicated ischemic stroke, stroke severity and mortality data, and complete covariates were included. Multinomial logistic regression models determined the association between stroke subtype (embolic vs thrombotic) and admission NIH Stroke Scale (NIHSS) category (minor [≤5], mild [6-10], moderate [11-15], severe [16-20], and very severe [>20]) adjusted for covariates from visits most proximal to the stroke. Separate ordinal logistic models evaluated for interaction by race and sex. Adjusted Cox proportional hazard models estimated the association between stroke subtype and all-cause mortality (through December 31, 2019).

RESULTS

Participants (N = 940) were mean age 71 years (SD = 9) at incident stroke, 51% female, and 38% Black. Using adjusted multinomial logistic regression, the risk of having a more severe stroke (reference NIHSS ≤5) was higher among embolic stroke vs thrombotic stroke patients, with a step-wise increase for embolic stroke patients when moving from mild (odds ratio [OR] 1.95, 95% CI 1.14-3.35) to very severe strokes (OR 4.95, 95% CI 2.34-10.48). After adjusting for atrial fibrillation, there was still a higher risk of having a worse NIHSS among embolic vs thrombotic strokes but with attenuation of effect (very severe stroke OR 3.91, 95% CI 1.76-8.67). Sex modified the association between stroke subtype and severity (embolic vs thrombotic stroke, p interaction = 0.03, per severity category, females OR 2.38, 95% CI 1.55-3.66; males OR 1.75, 95% CI 1.09-2.82). The risk of death (median follow-up 5 years, interquartile range 1-12) was also increased for embolic vs thrombotic stroke patients (hazard ratio 1.66, 95% CI 1.41-1.97).

DISCUSSION

Embolic stroke was associated with greater stroke severity at the time of the event and a higher risk of death vs thrombotic stroke, even after careful adjustment for patient-level differences.

Incidence of cardioembolic stroke related to atrial fibrillation in Joinville, Brazil

BACKGROUND

Atrial fibrillation (AF) is an important cause of cardioembolic stroke, and population aging has increased its prevalence.

OBJECTIVE

To evaluate the incidence of cardioembolic stroke caused by AF in the city of Joinville, Brazil, as well as previous diagnoses and use of medication.

METHODS

Between 2017 and 2020 we extracted data from the population-based Joinville Stroke Registry. Demographic characteristics, diagnosis of AF, and patterns of medication use were collected, and the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) system was used to classify the etiology.

RESULTS

There were 3,303 cases of ischemic stroke, 593 of which were cardioembolic, and 360 had AF. Of the patients with AF, 258 (71.6%) had a previous diagnosis of the disease, and 102 (28.3%) were newly diagnosed after the stroke. Among patients with a previously-diagnosed AF, 170 (47.2%) were using anticoagulants, and 88 (24.4%) were using other medications.

CONCLUSION

During the analyzed period, ischemic stroke caused by AF was a significant burden on the population of Joinville, and a considerable number of patients had undiagnosed or untreated AF.

Elevated visceral adiposity index is associated with increased stroke prevalence and earlier age at first stroke onset: Based on a national cross-sectional study

OBJECTIVE

The purpose of this study was to examine the association between the VAI (visceral adiposity index) and stroke prevalence and age at stroke in US adults.

METHODS

We examined the association between VAI and stroke prevalence and age at stroke using logistic regression, subgroup analysis, and dose-response curves using participants from the National Health and Nutrition Examination Survey (NHANES) database from 2007-2018.

RESULTS

This study ultimately included 29,337 participants aged >20 years, of whom 1022 self-reported a history of stroke, and after adjusting for all confounders, each unit increase in corrected VAI was associated with a 12% increase in the prevalence of stroke (OR= 1.12, 95% CI: 1.01, 1.24) along with an earlier age at stroke 1.64 years (β= -1.64, 95% CI: -2.84, -0.45), stratified analysis showed that the prevalence of stroke was 20% higher in the female group (OR= 1.20, 95% CI: 1.04, 1.39), black group (OR= 1.22, 95% CI: 1.01, 1.48), age ≤60 years group (OR= 1.25, 95% CI: 1.05, 1.48), hypertensive group (OR=1.15, 95% CI:1.01, 1.31), and diabetic group (OR=1.23, 95% CI:1.02, 1.48) VAI increase was positively correlated with stroke prevalence increase. The dose-response curves showed a positive linear correlation between increased VAI and stroke prevalence, while a negative linear correlation was observed between increased VAI and age at stroke.

CONCLUSION

Although a causal relationship cannot be proven, higher VAI was positively associated with stroke prevalence and can lead to earlier stroke onset.

Patterns and outcomes of stroke thrombolysis in a large tertiary care hospital in Riyadh, Saudi Arabia

Objectives:

To present the experience on stroke thrombolysis of a tertiary care center in Riyadh, KSA.

Methods:

Cross-sectional, observational study of patients thrombolyzed between January 2012 and December 2018.

Results:

Thrombolysis was performed in 148 patients (mean age: 58.2±14.5 years), 94 (63.5%) of them were men. The median onset-to-door time was 81 minutes, and 25% of the patients arrived within 1 hour. The median National Institute of Health Stroke Scale score upon admission was 13. Hypertension (68.9%), diabetes (56.1%), and dyslipidemia (40.5%) were the most common risk factors for stroke. The most common mechanism of stroke was cardioembolism (43.2%), which was associated with a more severe presentation (p=0.031). Intravenous thrombolysis alone was given to 98 patients (66.2%); the rest received intravenous tissue plasminogen activator plus endovascular therapy or endovascular therapy alone. The median door-to-needle (DTN) time was 70.5 min, with a significant improvement from 2012 (111.6 minutes) to 2018 (69.9 minutes) (p<0.001). Among the patients, 53 (35.8%) showed a good outcome (with a modified Rankin score of 0–2) whereas 14 (9.5%) died. Symptomatic intracranial hemorrhage (sICH) was seen in 8.1%. All vascular risk factors were more common in patients aged >60 years, except smoking, which was more common in the younger age group (p=0.007).

Conclusion:

In our cohort, the utilization of thrombolysis and the DTN time improved over time. One-thirds of the patients received endovascular treatment. Moreover, the frequency of the vascular risk factors was high. Compared with the published findings, our results showed that cardioembolic strokes were the most frequent and had severe presentation and were likely the cause of the slight increase in mortality and sICH.

First approach to distinguish between cardiac and arteriosclerotic emboli of individual stroke patients applying the histological THROMBEX-classification rule

Endovascular treatment of strokes caused by large vessel occlusion enables the histopathological investigation of the retrieved embolus, possibly providing a novel opportunity to contribute to the diagnostic workup of etiology and to define secondary prevention measures in strokes with uncertain genesis. We aimed to develop a classification rule based on pathophysiological considerations and adjustment to reference thrombi for distinction between cardiac and arteriosclerotic emboli and to validate this classification rule on a patient cohort. From 125 patients with stroke due to large vessel occlusion and thrombectomy, 82 patients with known etiology (55 cardioembolic and 27 arterioembolic strokes) were included. The corresponding emboli were histologically evaluated by two raters blinded to the etiology of stroke by means of a novel classification rule. Presumed etiology and classification results were compared. Agreement concerning cardiac emboli was 72.2% (95% CI: 58.4–83.5) for rater I and 78.2% (95% CI: 65.0–88.2) for rater II. Agreement concerning arteriosclerotic emboli was 70.4% (95% CI: 49.8–86.3) for rater I and 74.1% (95% CI: 53.7–88.9) for rater II. Overall agreement reached 71.6% (95% CI: 60.5–81.1) for rater I and 76.8% (95% CI: 66.2–85.4) for rater II. Within the limits of generally restricted accuracy of histological evaluations, the classification rule differentiates between cardiac and arteriosclerotic emboli of acute ischemic stroke patients. Further improvement is needed to provide valuable complementary data for stroke etiology workup.

Integrative Analysis of MAPK14 as a Potential Biomarker for Cardioembolic Stroke

The aim of this study was to obtain the candidate genes and biomarkers that are significantly related to cardioembolic stroke (CS) by applying bioinformatics analysis. In accordance with the results of the weighted gene coexpression network analysis (WGCNA) in the GSE58294 dataset, 11 CS-related coexpression network modules were identified in this study. Correlation analysis showed that the black and pink modules are significantly associated with CS. A total of 18 core genes in the black module and one core gene in the pink module were determined. We then identified differentially expressed genes (DEGs) of CS at 3 h, 5 h, and 24 h postonset. After performing intersection, it was found that 311 genes were coexpressed at these three time points. These genes were majorly enriched in positive regulation of transferase activity and regulation of peptidase activity. The abovementioned coexpressed DEGs were subjected to protein-protein interaction analysis and subnetwork module analysis. Subsequently, we used cytoHubba to obtain 11 key genes from DEGs. The intersection of the core genes screened from WGCNA and the key genes selected from DEGs yielded the MAPK14 gene. The expression level of MAPK14 on the receiver operating characteristic (ROC) curves of CS at 3 h, 5 h, and 24 h showed that the area under the ROC curve (AUC) was 0.923, 0.934, and 0.941, respectively. In a nutshell, MAPK14 screened out by using WGCNA showed differential expression in CS. We conclude that MAPK14 can be used as a potential biological marker of CS and exhibits potential to predict the physiopathological condition of CS patients.

CT angiography vs echocardiography for detection of cardiac thrombi in ischemic stroke: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Cardiac thrombi are an important cause of embolic stroke. We studied the diagnostic yield and diagnostic accuracy of cardiac CT angiography (CTA) compared to echocardiography for detection of cardiac thrombi in ischemic stroke patients.

METHODS

We performed a systematic review and meta-analysis of the literature on cardiac CTA versus echocardiography for detection of cardiac thrombi in ischemic stroke patients. We included studies (N ≥ 20) in which both cardiac CTA (index test) and echocardiography (reference test) were performed and data on cardiac thrombi were reported. Results were stratified for type of echocardiography: transesophageal (TEE) vs transthoracic (TTE).

RESULTS

Out of 1530 studies, 14 were included (all single center cohort studies), with data on 1568 patients. Mean age varied between 52 and 69 years per study and 66% were men. Reported time intervals ranged from 0 to 21 days between stroke and first test, and from 0 to 199 days between tests. In ten studies that compared CTA to TEE, CTA detected cardiac thrombi in 87/1385 (6.3%) patients versus 68/1385 (4.9%) on TEE (p < 0.001). In four studies comparing CTA to TTE, CTA detected thrombi in 23/183 (12.5%) patients versus 12/183 (6.6%) on TTE (p = 0.010). Pooled sensitivity and specificity of CTA versus TEE were 86.0% (95% CI 65.6-95.2) and 97.4% (95% CI 95.0-98.7), respectively.

CONCLUSIONS

CTA may be a promising alternative to echocardiography for detection of cardiac thrombi in patients with ischemic stroke, especially now that CTA is standard care for patient selection for endovascular treatment. However, studies were too heterogeneous and of insufficient methodological quality to draw firm conclusions. Large, prospective studies on this topic are warranted.

Non-vitamin K oral anticoagulants (NOACs) in patients with stroke and atrial fibrillation

Patients with atrial fibrillation who had a previous transient ischemic attack or ischemic stroke had a significantly high risk of stroke recurrence and the introduction of oral anticoagulants should be mandatory. However, the long-term use of oral anticoagulants increases the risk of developing all types of intracranial hemorrhages. The advantages of non-vitamin K oral anticoagulants (NOACs) compared to warfarin are that they have a significantly lower risk for hemorrhagic stroke. They are preferred in elderly patients, those with small vessel disease, or those with previous intracerebral hemorrhage. The time of NOACs introduction after an ischemic stroke depends on its severity and the rule "1-3-6-12" days should be applied. The reintroduction of NOACs in patients with atrial fibrillation and previous intracerebral hemorrhage depends on its etiology and should be after about 4-8 weeks if the cardioembolic risk is high and the risk for intracranial hemorrhage small.

Contrast Staining may be Associated with Intracerebral Hemorrhage but Not Functional Outcome in Acute Ischemic Stroke Patients Treated with Endovascular Thrombectomy

To evaluate the incidence of post-interventional contrast staining (PICS) in acute ischemic stroke (AIS) Chinese patients who were treated with endovascular thrombectomy (ET) and investigate potential association of PICS with functional outcome and intracerebral hemorrhage (ICH). This observational study was based on a single-center prospective registry study. AIS patients who underwent ET from January 2013 to February 2017 were recruited into this study. All patients had dual-energy CT (DECT) scan of the head at 12 to 24 hours post-ET. The primary outcome was the incidence of PICS. Secondary outcomes were total ICH, symptomatic ICH (sICH), 3-month functional outcome, and long-term functional outcome. One hundred and eighty patients were enrolled in this study. PICS was detected in 50 patients (28%) based on the post-interventional CT scan. We first used basic statistical analyses, showing that the incidence of both total ICH (60% vs. 25%, p<0.001) and sICH (18% vs. 8%, p=0.044) were higher in patients with PICS than those without, and fewer patients achieved no disability (mRS≤1) in the PICS group compared to the control group at both 3-month and long-term follow-up (p<0.01 each). However, multivariate regression analysis further revealed that PICS only increased total (adjusted odds ratio, 7.38; 95% confidence interval 1.66 to 32.9; p=0.009) but not sICH risk. Furthermore, the logistic regression analyses did not show statistical difference in good clinical outcomes or mortality between the two groups. PICS is a common phenomenon in Chinese AIS patients. It is associated with total ICH after ET, but it seems to have no effect on functional outcome and sICH. Further large-scale studies are warranted to validate these results.

[The efficacy of systemic thrombolysis in patients with cardioembolic stroke]

AIM

To compare the efficacy and safety of systemic thrombolytic therapy (STLT) in patients with cardioembolic stroke (CE) versus other pathogenic subtypes of ischemic stroke (IS).

MATERIAL AND METHODS

The study included 147 patients, 62 women and 85 men (mean age - 62.9±0.8 years) including 37 patients (25.2%) with CE subtype of IS (group 1) and 110 patients with other pathogenetic subtypes of IS (group 2). NIHSS and Rankin scale were used to assess patient's neurological status.

RESULTS

One hundred and twenty-six patients were discharged, 21 (14.3%) died. In 11 patients, the cause of death was the development of symptomatic hemorrhagic transformation (SHT). There were no significant differences in the lethality between groups 1 and 2. Tolerability to STLT in these groups did not differ as well. As a result of treatment, the condition of patients surviving to the end of the hospital stay improved, which was reflected in a significant decrease in the NIHSS scores, despite the higher NIHSS scores in group 1.

CONCLUSION

The results confirm the efficacy of STLT in patients with CE IS and indicate the increase in the frequency of favorable functional recovery in these patients.

Diagnosis and Management of Transient Ischemic Attack

PURPOSE OF REVIEW

This article reviews the diagnosis, investigation, and recommended management after a transient ischemic attack (TIA) and discusses how to make an accurate diagnosis, including the diagnosis of mimics of TIAs.

RECENT FINDINGS

Up to a 10% risk of recurrent stroke exists after a TIA, and up to 80% of this risk is preventable with urgent assessment and treatment. Imaging of the brain and intracranial and extracranial blood vessels using CT, CT angiography, carotid Doppler ultrasound, and MRI is an important part of the diagnostic assessment. Treatment options include anticoagulation for atrial fibrillation, carotid revascularization for symptomatic carotid artery stenosis, antiplatelet therapy, and vascular risk factor reduction strategies.

SUMMARY

TIA offers the greatest opportunity to prevent stroke that physicians encounter. A TIA should be treated as a medical emergency, as up to 80% of strokes after TIA are preventable.