Targeted Metabolomic Biomarkers for Stroke Subtyping

BACKGROUND AND PURPOSE

Ischemic stroke is a heterogeneous disease with various etiologies. The current subtyping process is complicated, time-consuming, and costly. Metabolite-based biomarkers have the potential to improve classification and deliver optimal treatments. We here aimed to identify novel, targeted metabolomics-based biomarkers to discriminate between large-artery atherosclerosis (LAA) and cardioembolic (CE) stroke.

METHODS

We acquired serum samples and clinical data from a hospital-based acute stroke registry (ischemic stroke within 3 days from symptom onset). We included 346 participants (169 LAA, 147 CE, and 30 healthy older adults) and divided them into training and test sets. Targeted metabolomic analysis was performed using quantitative and quality-controlled liquid chromatography with tandem mass spectrometry. A multivariate regression model using metabolomic signatures was created that could independently distinguish between LAA and CE strokes.

RESULTS

The training set (n = 193) identified metabolomic signatures that were different in patients with LAA and CE strokes. Six metabolomic biomarkers, i.e., lysine, serine, threonine, kynurenine, putrescine, and lysophosphatidylcholine acyl C16:0, could discriminate between LAA and CE stroke after adjusting for sex, age, body mass index, stroke severity, and comorbidities. The enhanced diagnostic power of key metabolite combinations for discriminating between LAA and CE stroke was validated using the test set (n = 123).

CONCLUSIONS

We observed significant differences in metabolite profiles in LAA and CE strokes. Targeted metabolomics may provide enhanced diagnostic yield for stroke subtypes. The pathophysiological pathways of the identified metabolites should be explored in future studies.

Association between internal carotid artery kinking and ischemic stroke: A population-based cross-sectional study

AIM

Evidence for an association between Internal carotid artery (ICA) kinking and ischemic stroke has been controversial. We aimed to examine the association between ICA tortuosity and risk of ischemic stroke and specific ischemic stroke subtypes (large artery atherosclerosis, LAA; small artery occlusion, SAO).

METHODS

A total of 419 outpatients were included in this cross-sectional study. ICA kinking was objectively assessed by head and neck computed tomography angiography (CTA). The risk of ischemic stroke for each patient was evaluated according to the Essen Stroke Risk Score (ESRS). Ischemic stroke subtypes (LAA and SAO) were measure with head magnetic resonance imaging (MRI).

RESULTS

The average age of patients was 59.1 years (SD = 13.25) and 264 (63.0 %) were males. The prevalence of ICA kinking in this sample was 31.5 % (132 out of 419). Individuals with ICA kinking was associated with 0.55-points increase in ESRS score than those without ICA kinking (95 % CI, 0.28-0.81, p < 0.001) among patients over 50 years. In addition, right ICA kinking or left ICA kinking were associated with 0.35-points (95 % CI, 0.08-0.63) and 0.49-points (95 % CI, 0.23-0.76) increase in ESRS score, respectively. For specific ischemic stroke subtypes, individuals with ICA kinking had a 10.34-fold increased risk of SAO compared to those without ICA kinking (95 % CI, 6.22-20.68). Individuals with right ICA kinking had a 4.51-fold risk of SAO than those without kinking (95 % CI, 2.64-7.71), and had an 8.86-fold risk of SAO than those without kinking in the left ICA kinking (95 % CI, 4.97-15.79).

CONCLUSION

Our findings support the role of ICA kinking on ischemic stroke. Early screening and proper treatment of carotid artery tortuosity could be a potential intervention strategy for the prevention of ischemic stroke later on.

Comparison of Safety and Efficacy after Emergency Stenting in Patients Exhibiting Intracranial Atherosclerotic Stenosis Associated with Large-vessel Occlusion with and without Intravenous Infusion of Tirofiban

PURPOSE

Intracranial rescue stent angioplasty is a bailout strategy for acute stroke patients in cases of unsuccessful endovascular thrombectomy due to underlying atherosclerotic stenosis. However, there is no consensus on a preprocedural and intraprocedural antiplatelet regimen. The aim of this single-centre study was to compare the safety and efficacy of emergency stenting in patients exhibiting intracranial atherosclerotic stenosis-related acute large-vessel occlusion with or without peri-interventional intravenous infusion of tirofiban.

MATERIALS AND METHODS

We performed a retrospective analysis of 78 patients who were treated with rescuestent angioplasty between 2010 and 2019 due to acute ischaemic stroke. The patients were divided into 2 groups: those who received peri-interventional intravenous tirofiban and those who did not receive tirofiban. We compared clinical safety and functional outcomes in both treatment groups with symptomatic haemorrhage as the primary endpoint. Bivariate and multivariable logistic regression was performed to investigate the association between tirofiban and outcome measures.

RESULTS

Thirty-seven patients were treated with intravenous tirofiban (47.4%), and 41 patients did not receive intravenous tirofiban (52.6%). Statistical analysis revealed no significant difference between the two groups in the rate of symptomatic haemorrhage (16.2% in the tirofiban group versus 14.6% in the control group, p = 0.847). The 3-month mortality (21.6% in the tirofiban group versus 17.1% in the control group, p = 0.611) and good functional outcomes according to the modified Rankin scale (45.9% versus 34.1%, p = 0.289) were comparable.

CONCLUSION

The results of our study suggest that the application of tirofiban for rescue stenting after failed mechanical thrombectomy is safe.

Point-of-care ultrasound for stroke patients in the emergency room

Stroke requires rapid determination of the cause to provide timely and appropriate initial management. Various ultrasonographic techniques have been evaluated as ways to determine the cause of stroke; among them, carotid artery ultrasonography is particularly useful since it provides considerable information within a short time period when used to evaluate a specific site. In the emergency room, carotid artery ultrasonography can be used to diagnose internal carotid artery stenosis, predict an occluded vessel, and infer the cause of ischemic stroke. Additionally, carotid artery ultrasonography can diagnose different conditions including subclavian artery steal syndrome, bow hunter's stroke, Takayasu's arteritis, moyamoya disease, and dural arteriovenous fistula. Furthermore, patients with ischemic stroke with a pulse deficit or hypotension must be differentiated from acute type A aortic dissection, which requires emergency surgery; carotid artery ultrasonography can immediately differentiate between the two conditions by identifying the intimal flap of the common carotid artery. The following article provides an overview of carotid artery ultrasonography performed as point-of-care ultrasound in the emergency room in patients with suspected stroke.

Lipoprotein(a) is associated with large artery atherosclerosis stroke aetiology and stroke recurrence among patients below the age of 60 years: results from the BIOSIGNAL study

AIMS

Lipoprotein(a) [Lp(a)] is a recognized causal risk factor for atherosclerotic cardiovascular disease but its role for acute ischaemic stroke (AIS) is controversial. In this study, we evaluated the association of Lp(a) with large artery atherosclerosis (LAA) stroke and risk of recurrent cerebrovascular events in AIS patients.

METHODS AND RESULTS

For this analysis of the prospective, observational, multicentre BIOSIGNAL cohort study we measured Lp(a) levels in plasma samples of 1733 primarily Caucasian (98.6%) AIS patients, collected within 24 h after symptom onset. Primary outcomes were LAA stroke aetiology and recurrent cerebrovascular events (ischaemic stroke or transient ischaemic attack) within 1 year. We showed that Lp(a) levels are independently associated with LAA stroke aetiology [adjusted odds ratio 1.48, 95% confidence interval (CI) 1.14-1.90, per unit log10Lp(a) increase] and identified age as a potent effect modifier (Pinteraction =0.031) of this association. The adjusted odds ratio for LAA stroke in patients aged <60 years was 3.64 (95% CI 1.76-7.52) per unit log10Lp(a) increase and 4.04 (95% CI 1.73-9.43) using the established cut-off ≥100 nmol/l. For 152 recurrent cerebrovascular events, we did not find a significant association in the whole cohort. However, Lp(a) levels ≥100 nmol/l were associated with an increased risk for recurrent events among patients who were either <60 years [adjusted hazard ratio (HR) 2.40, 95% CI 1.05-5.47], had evident LAA stroke aetiology (adjusted HR 2.18, 95% CI 1.08-4.40), or had no known atrial fibrillation (adjusted HR 1.60, 95% CI 1.03-2.48).

CONCLUSION

Elevated Lp(a) was independently associated with LAA stroke aetiology and risk of recurrent cerebrovascular events among primarily Caucasian individuals aged <60 years or with evident arteriosclerotic disease.

Association of Carotid Artery Endothelial Signal Intensity Gradient with Unilateral Large Artery Ischemic Stroke

BACKGROUND

Common carotid artery (CCA) and internal carotid artery (ICA) are aligned linearly, but their hemodynamic role in ischemic stroke has not been studied in depth.

OBJECTIVES

We aimed to investigate whether CCA and ICA endothelial shear stress (ESS) could be associated with the ischemic stroke of large artery atherosclerosis (LAA).

METHODS

We enrolled consecutive patients with unilateral ischemic stroke of LAA and healthy controls aged >60 years in the stroke center of Jeonbuk National University Hospital. All patients and controls were examined with carotid artery time-of-flight magnetic resonance angiography, and their endothelial signal intensity gradients (SIGs) were determined, as a measure of ESS. The effect of right or left unilateral stroke on the association between carotid artery endothelial SIG and ischemic stroke of LAA was assessed.

RESULTS

In total, the results from 132 patients with ischemic stroke of LAA and 121 controls were analyzed. ICA endothelial SIG showed significant and independent associations with the same-sided unilateral ischemic stroke of LAA, even after adjusting for the potential confounders including carotid stenosis, whereas CCA endothelial SIG showed a significant association with the presence of the ischemic stroke of LAA.

CONCLUSION

Although CCA and ICA are located with continuity, the hemodynamics and their roles in large artery ischemic stroke should be considered separately. Further studies are needed to delineate the pathophysiologic roles of ESS in CCA and ICA for large artery ischemic stroke.

4-Hydroxyl-2-Nonenal Localized Expression Pattern in Retrieved Clots is Associated with Large Artery Atherosclerosis in Stroke Patients

OBJECTIVES

The relationship between stroke etiology and clot pathology remains controversial.

MATERIALS AND METHODS

We performed histological analysis of clots retrieved from 52 acute ischemic stroke patients using hematoxylin and eosin staining and immunohistochemistry (CD42b and oxidative/hypoxic stress markers). The correlations between clot composition and the stroke etiological group (i.e., cardioembolic, cryptogenic, or large artery atherosclerosis) were assessed.

RESULTS

Of the 52 clots analyzed, there were no significant differences in histopathologic composition (e.g., white blood cells, red blood cells, fibrin, and platelets) between the 3 etiological groups (P = .92). By contrast, all large artery atherosclerosis clots showed a localized pattern with the oxidative stress marker 4-hydroxyl-2-nonenal (P < .01). From all 52 clots, 4-hydroxyl-2-nonenal expression patterns were localized in 28.8% of clots, diffuse in 57.7% of clots, and no signal in 13.5% of clots.

CONCLUSIONS

A localized pattern of 4-hydroxyl-2-nonenal staining may be a novel and effective marker for large artery atherosclerosis (sensitivity 100%, specificity 82%).

Evaluation of Clinical Features and Stroke Etiology in Patients with Bilateral Middle Cerebellar Peduncle Infarction

OBJECTIVE

The aim of this study was to characterize clinical features, etiologies, and mechanisms of strokes due to bilateral middle cerebellar peduncle infarction (BMCPI).

METHODS

Cases diagnosed as BMCPI in our hospital were retrieved, and a literature review was performed. Data on clinical features and brain MRI were obtained. Extracranial and intracranial segments of the vertebrobasilar artery were assessed by using digital subtraction angiography, magnetic resonance angiography, or computed tomography angiography.

RESULTS

Thirteen cases (11 men and 2 women) of BMCPI were identified. A high-intensity signal of diffusion-weighted imaging sequence involving the bilateral middle cerebellar peduncle was observed in all patients. Most patients experienced vertigo, dysarthria, ataxia, and hearing disorders. Eleven of these cases were classified as large artery atherosclerosis, one as traumatic vertebral artery (VA) dissection, and one as giant cell arteritis.

CONCLUSION

BMCPI is a rare cerebrovascular disease characterized by vertigo, ataxia, and dysarthria, which may also be accompanied by a hearing deficit or clinical signs of brainstem damage. BMCPI may be associated with hypoperfusion secondary to occlusive disease of the bilateral VA or proximal basilar artery.

Serum alpha-1 antitrypsin in acute ischemic stroke: A prospective pilot study

BACKGROUND

Alpha-1 antitrypsin (AAT) is a potent anti-protease enzyme which may play a role in arterial wall stability. A variant of its encoding gene has been recently linked to ischemic stroke due to large artery atherosclerosis (LAA). We sought to explore potential relationships between ischemic stroke mechanisms, atherosclerosis burden and serum AAT levels.

METHODS

We performed a prospective observational study of consecutive patients with acute ischemic stroke who were admitted to an academic comprehensive stroke center over a three-month period. Blood samples were collected within 24 h of hospital admission, and stroke subtype classification was determined based on modified TOAST criteria. Modified Woodcock scoring system was used to quantify calcification of major cervico-cranial arteries as a surrogate for atherosclerosis burden. Linear regression analysis was used to assess the association between serum AAT levels and calcification scores, both as continuous variables.

RESULTS

Among eighteen patients met our inclusion criteria and were enrolled in our study, 10 patients (56%) were men; mean age was 66 (SD 12.5); median NIH stroke scale was 4 (IQR 9.5); 8 patients (44%) had stroke due to LAA. The median serum level of AAT was 140 mg/dl (IQR 41.7) for patients with LAA-related stroke, and 148.5 mg/dl (IQR 37.7) for patients with other stroke mechanisms (p = 0.26). Higher serum AAT levels was associated with lower modified Woodcock calcification scores. (p-value = 0.038) CONCLUSIONS: Measurement of AAT levels in patients with acute stroke is feasible, and there may be associations between AAT levels and stroke mechanism that warrant further study in larger samples.

Effects of mechanical thrombectomy for acute stroke patients with etiology of large artery atherosclerosis

AIMS

Atherosclerosis is more prevalent in Asian population. This distinct etiology of stroke might disadvantage Asian patients when applying. mechanical thrombectomy (MT). The purpose of this research was to evaluate the efficacy and safety of MT in a cohort of Chinese patients with acute ischemic stroke. due to large artery atherosclerosis (LAA).

METHODS AND RESULTS

A total of 649 patients treated with MT were included. Patients were classified according to etiology of stroke as LAA and cardioembolism ones. Successful revascularization was defined as modified Thrombolysis in Cerebral Infarction (mTICI) grade ≥ 2b. Favorable outcome was defined as modified Rankin Scale (mRS) score ≤ 2 at 90 days. Logistic regression was used to identify predictors for functional outcomes. The patients with stroke of LAA etiology had significantly higher rate of favorable functional outcome (50.2% vs 36.5%, p < .001) and good collateral (grade of ASITN/SIRI: 2-3) (58.8% versus 43.2%, p < .001), and lower median baseline National Institutes of Health Stroke Scale score (NIHSS) (15.6 versus 18.2, p < .001), compared to patients with stroke of cardioembolism etiology. There was no significant difference in the rate of successful postprocedural mTICI between groups (84.5% versus 83.2%, p = .671). Rates of symptomatic intracranial hemorrhage (20.0% versus 11.7%, p = .004) and mortality (31.8% versus 18.8%, p < .001) within 3 months were notably higher in the cardioembolism group than that in the LAA group.

CONCLUSION

Mechanical thrombectomy may be more efficacious in treating acute ischemic stroke of LAA etiology than that of cardioembolism etiology.

Transient Ischaemic Attack Rarely Precedes Stroke in a Cohort with Low Proportions of Large Artery Atherosclerosis: A Population-Based Study

Background

Ischaemic stroke is reportedly preceded by transient ischaemic attack (TIA) in 15–30$ of all cases. The risk of stroke following TIA is highest in the presence of unstable atherosclerotic plaques in large arteries. The recent population-based Adelaide Stroke Incidence Study describes a population with a low proportion (16$) of stroke attributable to large artery atherosclerosis (LAA). We hypothesized that this population-based ischaemic stroke cohort would have a lower rate of preceding TIA than previously reported.

Methods

This paper is a prospective ascertainment of all suspected TIAs and strokes in a 12-month period from 2009 to 2010. Ischaemic stroke pathogenesis was classified by the TOAST criteria. Details of preceding TIA events were scrutinised.

Results

In this 12-month period, 318 stroke events in 301 individuals were recorded. Of the total 258 ischaemic strokes, 16$ (95$ confidence interval [CI] 12–22) were from LAA. Of 258 ischaemic stroke patients, only 11 (4$; 95$ CI 2–7) reported symptoms in the preceding 90 days consistent with TIA. Nine (82$) sought medical attention. The median ABCD² score in this group was 4.5 (IQR: 3–7), and the median time of event prior to stroke was 20 days (IQR: 4–32).

Conclusion

In our population-based cohort, rates of TIA preceding ischaemic stroke were much lower than previously reported, probably reflective of effective secondary prevention (active TIA clinics) and primary prevention (limiting LAA prevalence). In our population, further enhancements in TIA care will be of limited yield.

Low HDL-C levels are associated with cervicocerebral atherosclerotic stenosis in Southern Chinese patients with large artery atherosclerotic ischemic stroke

OBJECTIVES

The aim of this study is to investigate the association of HDL-C with CCAS, as well as its intracranial or extracranial location in the Southern Chinese population.

PATIENTS AND METHODS

123 Southern Chinese patients with large-artery atherosclerotic(LAA) ischemic stroke were enrolled for the final analysis. Based on the stenosis severity defined by digital subtraction angiography, the patients were categorized into CCAS and non-CCAS groups. The degree of artery stenosis among patients of CCAS was classified into three grades. CCAS were further categorized into intracranial AS (ICAS), Extracranial AS (ECAS) and combined intra-/extra-cranial AS (IECAS).

RESULTS

It was showed that patients with CCAS had a lower HDL-C level compared to NCCAS, and HDL-C levels were correlated to the degree of artery stenosis among CCAS. After adjusting for multiple potential confounders, low HDL-C level remained independently associated with CCAS(adjusted OR = 2.860). Patients with the lowest HDL-C quartile had a significantly increased risk for CCAS(adjusted OR: 5.771), referred to the highest quartile. But HDL-C levels in patients with ICAS, ECAS and IECAS were not significantly different, and there was no significant correlation between HDL-C levels and ICAS.

CONCLUSION

Our data indicate that low HDL-C level is associated with CCAS in Southern Chinese patients with LAA ischemic stroke. But the effects of HDL-C on the distribution of CCAS is required to be further explored.

New clinical characteristics and risk factors of hand knob infarction

Hand knob infarction (HKI) is a rare clinical condition which is often misdiagnosed as peripheral neuropathy. This study aimed to identify the clinical characteristics and risk factors of HKI. Nine HKI patients admitted between January 2013 and March 2016 were confirmed by magnetic resonance imaging. Their medical records were collected and analyzed. The modified Rankin Scale was used to assess clinical outcomes. Routine laboratory tests, electrocardiogram, echocardiography, cranial magnetic resonance imaging, magnetic resonance angiography, computed tomography angiography, and Doppler ultrasonography examinations were performed. Seven patients had uniform involvement of all digits. One patient with radial weakness had a lesion in the lateral area of hand knob, and another patient with ulnar weakness had a lesion distributed in the medial area of hand knob. Hyperhomocysteinemia was a most common risk factor for HKI. Most HKI patients had a benign disease course, but three patients (33.33%) with the stroke type of large artery atherosclerosis had disease recurrence. We characterized clinical characteristics and risk factors of HKI which will help the diagnosis and management of HKI.

Reduced Serum Level of Interleukin-10 is Associated with Cerebral Infarction: A Case-Control and Meta-Analysis Study

IL-10 expression limits inflammation and restricts the size of CNS damage from stroke. In this study, we examined the correlation between cerebral infarction (CI) and serum levels of interleukin-10 (IL-10) using a combination of case-control study and meta-analysis of published data, with an aim of understanding the relevance of serum IL-10 levels to CI development. This study enrolled a total of 169 CI patients admitted to the Second Hospital of Hebei Medical University between May 2011 and November 2014. During the same period, a group of 145 individuals were recruited at the same hospital as healthy controls after thorough physical examination. Serum IL-10 levels were measured by enzyme-linked immunosorbent assay (ELISA). SPSS 19.0 (IBM, 2010, Chicago, IL, USA) and Comprehensive Meta-Analysis 2.0 (CMA 2.0) software were used for data analysis. Serum levels of IL-10 (pg/mL) were significantly lower in CI patients when compared to healthy controls (15.36 ± 3.21 vs. 21.64 ± 5.17, t = 13.12, P < 0.001). In addition, patients with large artery atherosclerosis (LAAS), cardioembolic infarct (CEI), and lacunar infarct (LAC) displayed drastically reduced serum levels of IL-10 (pg/mL) compared to healthy controls (LAAS 14.77 ± 5.21, CEI 15.25 ± 5.10, LAC 16.58 ± 4.92, all P < 0.001). Interestingly, no significant differences were observed in the serum IL-10 levels when pair-wise comparisons were made between these three clinical subtypes of CI (all P > 0.05). Logistic regression analysis indicated that, with the exception of triglyceride (TG) and uric acid (UA) levels (both P > 0.05), the other seven parameters, including fasting blood glucose (FPG), total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), creatinine (Cr), systolic blood pressure (SBP), and diastolic blood pressure (DBP), strongly correlated with CI development (all P < 0.05). Meta-analysis of pooled data from nine case-control studies revealed an inverse correlation between the serum IL-10 levels and CI (SMD = 1.797, 95% CI 0.785~2.810, P = 0.001). Subgroup analysis based on country showed that low serum levels of IL-10 may be the major risk factor for CI in Croatia (SMD = 2.961, 95% CI 2.480~3.443, P < 0.001) and India (SMD = 1.440, 95% CI 1.129-1.750, P < 0.001). Further, subgroup analysis based on ethnicity showed that IL-10 serum levels and CI displayed negative relationship in Asians (SMD = 2.522, 95% CI 0.468~4.576, P = 0.016) but not in Caucasians (P > 0.05). Our study provided convincing evidence that the patients with CI exhibit consistently reduced serum levels of IL-10, and IL-10 may be a major player in the development and progression of CI.

The single nucleotide polymorphism rs2208454 confers an increased risk for ischemic stroke: a case-control study

AIM

A recent genome-wide association study identified a strong association of covert magnetic resonance imaging infarcts with the single nucleotide polymorphism (SNP) rs2208454. The aim of this study was to determine whether the rs2208454 polymorphism is associated with an increased risk for ischemic stroke (IS).

METHODS

Ischemic stroke patients (n = 712) and control subjects (n = 774) from a southern Chinese Han population were included. The snapshot technique was used for genotype analysis.

RESULTS

Compared with the GT+GG or GG genotype, the frequency of the TT genotype was significantly higher in IS than in controls. After adjusting for age, gender, family history of IS, hypertension history, and history of diabetes mellitus, a significant correlation between the TT genotype and IS persisted (TT vs. GT+GG: adjusted OR = 1.79, 95% CI: 1.16-2.77; TT vs. GG: adjusted OR = 1.88, 95% CI: 1.20-2.94). In subgroup analyses, SNP rs2208454 was significantly associated with large artery atherosclerosis (LAA) (TT vs. GG: adjusted OR = 2.16, 95% CI: 1.19-3.93), but failed to show significant association with small-artery occlusion or cardioembolism IS subtypes.

CONCLUSIONS

Single nucleotide polymorphism rs2208454 confers an increased risk for IS in a southern Chinese Han population. When the IS subtype was examined, the effect of the SNP was restricted to LAA.