Association of neutrophil count with microembolization in patients with symptomatic carotid artery stenosis

Intersecting Pathways: The Role of Metabolic Dysregulation, Gastrointestinal Microbiome, and Inflammation in Acute Ischemic Stroke Pathogenesis and Outcomes

Acute ischemic stroke (AIS) remains a major cause of mortality and long-term disability worldwide, driven by complex and multifaceted etiological factors. Metabolic dysregulation, gastrointestinal microbiome alterations, and systemic inflammation are emerging as significant contributors to AIS pathogenesis. This review addresses the critical need to understand how these factors interact to influence AIS risk and outcomes. We aim to elucidate the roles of dysregulated adipokines in obesity, the impact of gut microbiota disruptions, and the neuroinflammatory cascade initiated by lipopolysaccharides (LPS) in AIS. Dysregulated adipokines in obesity exacerbate inflammatory responses, increasing AIS risk and severity. Disruptions in the gut microbiota and subsequent LPS-induced neuroinflammation further link systemic inflammation to AIS. Advances in neuroimaging and biomarker development have improved diagnostic precision. Here, we highlight the need for a multifaceted approach to AIS management, integrating metabolic, microbiota, and inflammatory insights. Potential therapeutic strategies targeting these pathways could significantly improve AIS prevention and treatment. Future research should focus on further elucidating these pathways and developing targeted interventions to mitigate the impacts of metabolic dysregulation, microbiome imbalances, and inflammation on AIS.

Molecular Pathways of Vulnerable Carotid Plaques at Risk of Ischemic Stroke: A Narrative Review

The concept of vulnerable carotid plaques is pivotal in understanding the pathophysiology of ischemic stroke secondary to large-artery atherosclerosis. In macroscopic evaluation, vulnerable plaques are characterized by one or more of the following features: microcalcification; neovascularization; lipid-rich necrotic cores (LRNCs); intraplaque hemorrhage (IPH); thin fibrous caps; plaque surface ulceration; huge dimensions, suggesting stenosis; and plaque rupture. Recognizing these macroscopic characteristics is crucial for estimating the risk of cerebrovascular events, also in the case of non-significant (less than 50%) stenosis. Inflammatory biomarkers, such as cytokines and adhesion molecules, lipid-related markers like oxidized low-density lipoprotein (LDL), and proteolytic enzymes capable of degrading extracellular matrix components are among the key molecules that are scrutinized for their associative roles in plaque instability. Through their quantification and evaluation, these biomarkers reveal intricate molecular cross-talk governing plaque inflammation, rupture potential, and thrombogenicity. The current evidence demonstrates that plaque vulnerability phenotypes are multiple and heterogeneous and are associated with many highly complex molecular pathways that determine the activation of an immune-mediated cascade that culminates in thromboinflammation. This narrative review provides a comprehensive analysis of the current knowledge on molecular biomarkers expressed by symptomatic carotid plaques. It explores the association of these biomarkers with the structural and compositional attributes that characterize vulnerable plaques.

Meta-analysis of the Relationship Between Neutrophil to Lymphocyte Ratio and Nasal Polyps

Our study aimed to enhance understanding of nasal polyp pathophysiology by reviewing the data for variations of NLR values between patients with nasal polyp and healthy controls. We searched Web of Science, PubMed, ProQuest, and Scopus up to 2 April 2023. The search strategy was not limited to any specific language. Twelve studies were included in our study. Of them, ten studies, involving 898 nasal polyp patients and 590 control patients, were included in the meta-analysis. The NLR levels in nasal polyp patients were statistically greater than in the control group (SMD = 0.56; 95%CI 0.04-1.08, P = 0.036). Subgroup analysis based on study design yielded that patients with nasal polyp exhibited significantly higher NLR levels than healthy controls in retrospective studies (SMD = 0.83; 95%CI 0.30-1.35, P = 0.002) but not in prospective studies (SMD = 0.10; 95%CI = -1.03 to 1.23, P = 0.85). Also, we found that the NLR levels in nasal polyp patients were significantly higher than healthy controls in high-quality studies (SMD = 1.00; 95%CI 0.38-1.62, P = 0.002) but not in low-quality studies (SMD = 0.11; 95%CI = -0.69 to 0.91, P = 0.79). A total of 312 patients with recurrence and 550 patients without recurrence were included in the study. The combined results revealed that NLR levels in nasal polyp recurrence patients were significantly higher than those of the nasal polyp without recurrence group (SMD = 0.06, 95% CI 0.39-0.81, P = 0.000). These results showed the relationship between the NLR in nasal polyps and can help medical doctors to predict the recurrence of the disease in such patients.

The thrombus proteome in stroke reveals a key role of the innate immune system and new insights associated with its etiology, severity, and prognosis

BACKGROUND

Nowadays little is known about the molecular profile of the occluding thrombus of patients with ischemic stroke.

OBJECTIVES

To analyze the proteomic profile of thrombi in patients who experienced an ischemic stroke in order to gain insights into disease pathogenesis.

METHODS

Thrombi from an exploratory cohort of patients who experienced a stroke were obtained by thrombectomy and analyzed by sequential window acquisition of all theoretical spectra-mass spectrometry. Unsupervised k-means clustering analysis was performed to stratify patients who experienced a stroke. The proteomic profile was associated with both the neurological function (National Institute of Health Stroke Scale [NIHSS]) and the cerebral involvement (Alberta Stroke Program Early CT Score [ASPECTS]) prior to thrombectomy and the clinical status of patients at 3 months using the modified Rankin Scale. In an independent cohort of 210 patients who experienced a stroke, the potential role of neutrophils in stroke severity was interrogated.

RESULTS

Proteomic analysis identified 580 proteins in thrombi, which were stratified into 4 groups: hemostasis, proteasome and neurological diseases, structural proteins, and innate immune system and neutrophils. The thrombus proteome identified 3 clusters of patients with distinctive severity, prognosis, and etiology of the stroke. A protein signature clearly distinguished atherothrombotic and cardioembolic strokes. Several proteins were significantly correlated with the severity of the stroke (NIHSS and ASPECTS). Functional proteomic analysis highlighted the prominent role of neutrophils in stroke severity. This was in line with the association of neutrophil activation markers and count with NIHSS, ASPECTS, and the modified Rankin Scale score 90 days after the event.

CONCLUSION

The use of sequential window acquisition of all theoretical spectra-mass spectrometry in thrombi from patients who experienced an ischemic stroke has provided new insights into pathways and players involved in its etiology, severity, and prognosis. The prominent role of the innate immune system identified might pave the way for the development of new biomarkers and therapeutic approaches in this disease.

An Elevated Neutrophil-to-Lymphocyte Ratio Predicts In-Hospital Mortality in Stroke Patients: A Prospective Cohort Study

Introduction Cerebrovascular accidents or strokes are a major cause of mortality and morbidity in today's world. Post-stroke disabilities like paralysis, dementia, etc., can affect the quality of life of patients as well as their families. A combined increase in neutrophils and a decrease in lymphocytes during inflammation in stroke manifests as an elevated neutrophil-to-lymphocyte ratio (NLR), thereby indicating the severity of neural damage. Aim We aimed to determine if an elevated NLR observed on the day of hospital admission can predict a higher risk of in-hospital mortality in stroke patients. Confirmatory results could aid in developing risk stratification for management, ultimately improving clinical and functional outcomes. Materials and methods Sixty stroke patients were monitored throughout their hospital stay in this prospective cohort study. NLR was calculated at admission using routine complete blood counts. The data were analyzed using SPSS Software v23.0 (IBM Corp., Armonk, NY). An unpaired t-test was used to compare the means between the two groups. Categorical data were analyzed using the chi-square test. The receiver operating curve (ROC) was plotted and used to ascertain if a cut-off value of NLR could be obtained to predict in-hospital mortality in stroke patients. P values <0.05 were considered statistically significant. Results About 23.3% (n=14) of the patients died during their hospital stay, with no significant differences between the survivor and death cohorts in terms of comorbidities like diabetes and hypertension. The mean NLR calculated within 24 hours of hospital admission in patients who died (NLR=8.47 (standard deviation (SD)=4.67)) was significantly higher (p=0.009) than in those who survived (NLR=5.84 (SD=2.62)). Upon ROC analysis, patients with NLR >6.03 on the day of admission demonstrated a higher risk of in-hospital mortality (p=0.015 (95% CI: 0.577-0.855)). An area under the curve (AUC) of 0.72 with a sensitivity of 92.86% and a specificity of 54.35% was obtained. Conclusions Elevated NLR (cut-off >6.03) obtained within 24 hours of hospital admission is an indicator of a higher risk of in-hospital mortality in stroke patients. Hence, patients presenting with a high NLR at admission can be prioritized for personalized targeted treatment, potentially reducing mortality and post-stroke complications.

Dual antiplatelet therapy improves functional recovery and inhibits inflammation after cerebral ischemia/reperfusion injury

Background

Dual antiplatelet therapy with aspirin and clopidogrel (ASA + CPG) during the first 21 days has been shown to reduce the risk of major ischemic events in patients with transient ischemic attack (TIA) or minor stroke. However, the mechanisms underlying combination treatment with ASA + CPG in experimental ischemic stroke has not been fully elucidated.

Methods

Minor cerebral ischemia was induced in mice by transient distal middle cerebral artery occlusion (tdMCAO). Two doses of ASA + CPG (12 and 24 mg/kg/day) or vehicle were administered by gavage daily. Neurological behaviors were assessed using the modified Garcia scores, Rotarod test, Y maze, and open field test. Platelet function was assessed in vitro by flow cytometry and in vivo by bleeding and clotting time. The neutrophil ratio and the levels of inflammatory cytokines were measured by flow cytometry and the Meso Scale Discovery (MSD) electrochemilunimescence, respectively.

Results

Sensorimotor function was partially recovered with ASA + CPG treatment after ischemia. Anxiety levels and cognitive functions showed improvement in the ASA + CPG group at 12 mg/kg/day after 21 days. Both tail bleeding time and flow cytometry showed significantly decreased platelet function after ASA + CPG treatment. Notably, ASA + CPG at 12 mg/kg/day prolonged clotting time at 28 days after injury. Furthermore, the ratio of neutrophils, an indicator of inflammation, was reduced with 12 mg/kg/day ASA + CPG treatment in the bone marrow (BM) at 21 days and in the peripheral blood (PB) at 21 and 28 days after tdMCAO. Both doses of ASA + CPG decreased pro-inflammatory cytokine interleukin (IL)-6 expression 21 days after stroke. Taken together, these results demonstrated that combination treatment with ASA + CPG improved long-term neurological function after stroke and may inhibit platelet-neutrophil interaction by decreasing the concentration of pro-inflammatory cytokine, IL-6.

Conclusions

These findings indicate a neuroprotective effect of combination treatment with ASA + CPG for a duration of 21 days in an experimental acute minor stroke model. These findings provide further evidence that dual antiplatelet therapy may be a viable neuroprotective treatment to decrease the recurrence of stroke.

Predictive Value of Complete Blood Count-Derived Inflammatory Markers for 5-Year Survival After Carotid Endarterectomy: Implications for Practice

Complete blood count inflammatory markers (CBC-IMs) have been associated with cardiovascular diseases and mortality. We aimed to evaluate the relationship between preoperative CBC-IMs and 5-year survival after carotid endarterectomy (CEA). Retrospective analysis of 411 consecutive patients who underwent CEA between 2004 and 2018 was done. CBC-IM included the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte (LMR) ratio, and systemic immune-inflammation index (SII). Survival rate at 5 years was 79.8%. Age (hazard ratio (HR) = 1.05, P = .003), hemoglobin (HR = 0.78, P < .001), heart failure (HR = 2.91, P = .005), American Society of Anesthesiologists (ASA)-IV score (HR = 2.41, P = .043), and active neoplastic disease (HR = 2.61, P = .028) were independently related to survival. The discrimination of this model (C-statistic) was 0.698. Spline analysis showed a linear relationship between survival and NLR (P < .001), PLR (P < .001), and SII (P < .001). After adjusting for the baseline predictive score, there was a significant relationship between survival and NLR (HR = 1.191, P = .001), PLR (HR = 1.004, P = .017), and SII (HR = 1.001, P < .001). The addition of NLR, PLR, and SII to the survival model improved the continuous net reclassification index (c-NRI) by 0.29 (P = .028), 0.347 (P = .008), and 0.481 (P < .001), respectively, but not the C-statistic. CBC-IMs show a linear and independent relationship with 5-year survival after CEA and may moderately contribute to patient selection for this preventive intervention.

Correlation between neutrophil-to-lymphocyte ratio and stability of carotid plaques

OBJECTIVE

The neutrophil-to-lymphocyte ratio (NLR) has been proved to be a strong predictor of carotid atherosclerotic plaque, but the correlation between NLR and the stability of carotid plaque is not clear. Thus we conducted a study to evaluate the correlation between NLR and the stability of carotid atherosclerotic plaque, and to develop a new evaluation scale for rapid clinical evaluation of carotid plaque stability.

METHODS

We recruited 528 patients with acute anterior circulation ischemic stroke who were in accordance with extracranial and intracranial large artery atherosclerosis of Chinese ischemic stroke subtype. Blood routine examination and carotid ultrasound examination were performed on admission. According to the ultrasonic characteristics, the patients were divided into plaque stabilization group and plaque instability group.

RESULTS

There was significant difference in NLR between plaque stability and instability groups (P < 0.001). The risk of plaque instability increased with the increase of NLR (odds ratio (OR), 4.737; 95% confidence interval (CI), 3.404-6.592; P < 0.001). Receiver operating characteristic (ROC) curve showed that the critical point of NLR is 2.55 and the area under the curve (AUC) was 0.782 (95%CI, 0.740-0.823; P < 0.001). The best cut-off value of the evaluation scale was ≥ 4 points (sensitivity, 0.77; specificity, 0.75; accuracy, 0.76).

CONCLUSION

There is a correlation between NLR and carotid plaque instability. NLR may be useful as a potential inflammation biomarker indicating the risk of unstable carotid plaques. The new scoring scale is a reliable index to predict the stability of carotid plaque.

Elevated Neutrophil to Lymphocyte Ratio is Associated with Worse Outcomes after Carotid Endarterectomy in Asymptomatic Patients

OBJECTIVE

Management of carotid artery stenosis (CAS) remains controversial and proper patient selection critical. Elevated neutrophil to lymphocyte ratio (NLR) has been associated with poor outcomes after vascular procedures. The effect of NLR on outcomes after carotid endarterectomy (CEA) in asymptomatic and symptomatic patients is assessed.

MATERIALS AND METHODS

A retrospective review was conducted of all patients between 2010 and 2018 with carotid stenosis >70% as defined by CREST 2 criteria. A total of 922 patients were identified, of whom 806 were treated with CEA and 116 non-operatively with best medical therapy (BMT). Of patients undergoing CEA, 401 patients (290 asymptomatic [aCEA], 111 symptomatic [sCEA]) also had an available NLR calculated from a complete blood count with differential. All patients treated with BMT were asymptomatic and had a baseline NLR available. Kaplan-Meier analysis assessed composite ipsilateral stroke or death over 3 years.

RESULTS

In sCEA group, the 3-year composite stroke/death rates did not differ between NLR < 3.0 (22.9%) vs NLR > 3.0 (38.1%) (P=.10). In aCEA group, patients with a baseline NLR >3.0 had an increased risk of 3-year stroke/death (42.6%) compared to both those with NLR <3.0 (9.3%, P<.0001) and those treated with BMT (23.6%, P=.003). In patients with NLR <3.0, aCEA showed a superior benefit over BMT with regard to stroke or death (9.3% vs. 26.2%, P=.02). However, in patients with NLR >3.0, there was no longer a benefit to prophylactic CEA compared to BMT (42.6% vs. 22.2%, P=.05). Multivariable analysis identified NLR >3.0 (HR, 3.23; 95% CI, 1.93-5.42; P<.001) and congestive heart failure (HR, 2.18; 95% CI, 1.33-3.58; P=.002) as independent risk factors for stroke/death in patients with asymptomatic carotid artery stenosis.

CONCLUSIONS

NLR >3.0 is associated with an increased risk of late stroke/death after prophylactic CEA for asymptomatic carotid artery stenosis, with benefits not superior to BMT. NLR may be used to help with selecting asymptomatic patients for CEA. The effect of NLR and outcomes in symptomatic patients requires further study. Better understanding of the mechanism(s) for NLR elevation and medical intervention strategies are needed to modulate outcome risk in these patients.

Non-stenotic Carotid Plaques in Embolic Stroke of Unknown Source

Embolic stroke of unknown source (ESUS) represents one in five ischemic strokes. Ipsilateral non-stenotic carotid plaques are identified in 40% of all ESUS. In this narrative review, we summarize the evidence supporting the potential causal relationship between ESUS and non-stenotic carotid plaques; discuss the remaining challenges in establishing the causal link between non-stenotic plaques and ESUS and describe biomarkers of potential interest for future research. In support of the causal relationship between ESUS and non-stenotic carotid plaques, studies have shown that plaques with high-risk features are five times more prevalent in the ipsilateral vs. the contralateral carotid and there is a lower incidence of atrial fibrillation during follow-up in patients with ipsilateral non-stenotic carotid plaques. However, non-stenotic carotid plaques with or without high-risk features often coexist with other potential etiologies of stroke, notably atrial fibrillation (8.5%), intracranial atherosclerosis (8.4%), patent foramen ovale (5-9%), and atrial cardiopathy (2.4%). Such puzzling clinical associations make it challenging to confirm the causal link between non-stenotic plaques and ESUS. There are several ongoing studies exploring whether select protein and RNA biomarkers of plaque progression or vulnerability could facilitate the reclassification of some ESUS as large vessel strokes or help to optimize secondary prevention strategies.

The Predictive Role of a Novel Risk Index in Patients Undergoing Carotid Artery Stenting: Systemic Immune-Inflammation Index

BACKGROUND

Inflammatory mechanisms play an important role in both atherosclerosis and stroke. There are several inflammatory peripheral blood count markers associated with carotid artery stenosis degree, symptomatic carotid artery lesions and carotid artery stent restenosis that reported in previous studies. However, the prognostic role of the blood cell counts and their ratios in predicting in-hospital and long-term outcomes in patients undergoing carotid artery stenting (CAS) has not been comprehensively investigated. Systemic immune-inflammation index (SII) proved its' efficiency in patients with solid tumors and its' role was rarely examined in cardiovascular disorders and stroke. The current study evaluated the effect of this novel risk index on in-hospital and long-term outcomes in a large patient population who underwent CAS.

METHOD

A total of 732 patients with carotid artery stenosis who underwent CAS were enrolled to the study. SII was calculated using the following formula: neutrophil-to-lymphocyte ratio × total platelet count in the peripheral blood (per mm3) and the patients were stratified accordingly: T1, T2 and T3. In-hospital and 5-year outcomes were compared between the tertiles of SII.

RESULTS

During the hospitalization, major stroke, ipsilateral stoke, myocardial infarction, death and major adverse cardiovascular events (MACE) rates were significantly higher in high SII level (T3) compared to SII levels (T1 and 2). In long-term outcomes, ipsilateral stroke, major stroke, transient ischemic attack, death, and MACE were significantly higher in the patients with higher SII level (T3). The 5-year Kaplan-Meier overall survival for T1, T2, and T3 were 97.5%, 96.7% and 86.0% respectively. In-hospital and 5-year regression analyses demonstrated that high SII was independently associated with MACE and mortality.

CONCLUSION

SII was independently associated with in-hospital and long-term clinical outcomes in patients undergoing CAS. Immune and inflammation status, as assessed easily and quickly using SII, has a good discriminative value in these patients.

Associations of the neutrophil to lymphocyte ratio with intracranial artery stenosis and ischemic stroke

Background

The neutrophil-to-lymphocyte ratio (NLR) has emerged as an inflammatory marker. However, the associations of NLR with intracranial artery stenosis (ICAS) and ischemic stroke remain unclear. This study aimed to examine the associations of NLR with ICAS and ischemic stroke among a large and high-risk population.

Methods

Participants with records of clinical characteristics were prospectively recruited from the Neurology Department and Health & Physical Examination Center of Qingdao Municipal Hospital. Logistic regression analysis was used to examine the associations of NLR with ICAS and ischemic stroke. Moreover, we also conducted parametric mediation analysis to estimate the effect of NLR on the risk of ischemic stroke mediated through ICAS.

Results

A total of 2989 participants were enrolled in this study. After adjusting for covariates, NLR (OR = 1.125, 95%CI 1.070–1.183) and ICAS (OR = 1.638, 95%CI 1.364–1.967) were significantly associated with ischemic stroke. Compared with the first quartile NLR, the second, third and fourth quartiles NLR were independent risk predictors for ischemic stroke (P for trend < 0.001); the third and fourth quartiles were independent predictors for ICAS (P for trend < 0.001). The mediation analysis showed that ICAS partially mediated the association between NLR and ischemic stroke, accounting for 14.4% of the total effect (P < 0.001).

Conclusions

NLR was significantly associated with ICAS and ischemic stroke. Besides, ICAS partially mediated the association between NLR and ischemic stroke.

Cerebrovascular risk factors associated with ischemic stroke in a young non-diabetic and non-hypertensive population: a retrospective case-control study

Background

Globally, rates of ischemic stroke (IS) have been rising among young adults. This study was designed to identify risk factors associated with IS incidence in young adults unaffected by hypertension or diabetes.

Methods

This was a retrospective case-control study of early-onset IS patients without diabetes and hypertension. Control patients were matched with healthy individuals based upon sex, age (±2 years), and BMI (±3 kg/m²) at a 1:3 ratio. Sociodemographic, clinical, and risk factor-related data pertaining to these patients was collected. The association between these risk factors and IS incidence was then assessed using conditional logistic regression models.

Results

We recruited 60 IS patients and 180 controls with mean ages of 44.37 ± 4.68 and 44.31 ± 4.71 years, respectively, for this study. Relative to controls, IS patients had significantly higher total cholesterol (TG), homocysteine (HCY), white blood cell (WBC), absolute neutrophil count (ANC), systolic blood pressure (SBP), and diastolic blood pressure (DBP) levels, and significantly lower high-density lipoprotein cholesterol (HDL-C) and triglyceride cholesterol (TC), free triiodothyronine (FT3), and free thyroxine (FT4) levels (all P < 0.05). After controlling for potential confounding factors, HCY and ANC were found to be significantly positively associated with IS incidence (OR 1.518, 95%CI 1.165–1.977, P = 0.002 and OR 2.418, 95%CI 1.061–5.511, P = 0.036, respectively), whereas HDL-C and FT3 levels were negatively correlated with IS incidence (OR 0.001, 95%CI 0.000–0.083, P = 0.003 and OR 0.053, 95%CI 0.008–0.326, P = 0.002, respectively).

Conclusions

In young non-diabetic and non-hypertensive patients, lower HDL-C and FT3 levels and higher HCY and ANC levels may be associated with an elevated risk of IS. Additional prospective studies of large patient cohorts will be essential to validate these findings.

Inflammation of carotid plaques and risk of cerebrovascular events

Carotid atherosclerotic plaques represent a risk for ischemic stroke. The data indicate that the risk for distal embolization from atherosclerotic lesions in internal carotid arteries is not related only to the degree of stenosis but also to the composition of plaques. The stability of atherosclerotic plaque depends on the thickness of the fibrous cap and plaque hemorrhage. Recent research indicated that the inflammatory activity of atherosclerotic lesions is pivotal in the progression of atherosclerotic plaques. It also promotes the development of unstable atherosclerotic lesions and is related to thromboembolic cerebrovascular complications. Inflammation destabilizes atherosclerotic plaques through the degradation of their fibrotic structure. Inflammation of atherosclerotic plaques was confirmed by histopathologic findings and levels of circulating inflammatory markers which were correlated to the intensity of the inflammation in atherosclerotic lesions. Recently, new techniques like fluorodeoxyglucose positron emission tomography (18-FDG PET) were developed for the identification of inflammation of atherosclerotic lesions in the vessel wall in vivo. Systemic inflammatory markers, particularly interleukins, tumor necrosis factor-alpha and metalloproteinases were shown to be related to the intensity of the inflammatory process in atherosclerotic lesions and the cerebrovascular events. Identification of inflamed atherosclerotic plaques may help to identify unstable atherosclerotic lesions and subjects at high risk for cerebrovascular incidents who need intensive preventive measures including anti-inflammatory medication.

Association of elevated hs-CRP and multiple infarctions with outcomes of minor stroke or TIA: subgroup analysis of CHANCE randomised clinical trial

Background and purpose

The relationship of high-sensitive C-reactive protein (hs-CRP) levels and infarction numbers with the prognosis of stroke is uncertain. This study evaluated the association of different hs-CRP levels and infarction numbers with the prognosis of acute minor ischaemic stroke or transient ischaemic attack (TIA).

Methods

A subset of 807 patients with both hs-CRP measurement and baseline MRI was included from the Clopidogrel in High-risk Patients with Acute Non-disabling Cerebrovascular Events trial. The primary efficacy outcome was the occurrence of an ischaemic stroke at the 1-year follow-up. Infarction numbers were classified as multiple acute infarctions (MAIs), single acute infarction and no acute infarction (NAI). The association between different hs-CRP levels with different infarction numbers and the risk of any outcome was analysed using multivariable Cox regression models.

Results

Among the 807 patients, 84 (10.4%) patients had a recurrent ischaemic stroke within 1 year. After adjustment for conventional confounding factors, patients with both elevated hs-CRP levels and MAIs were associated with approximately 4.7-fold of risk of ischaemic stroke within 1 year (16.7% vs 3.5%, HR 4.68, 95% CI 1.54 to 14.23, p=0.007), compared with those with non-elevated hs-CRP levels and NAI. Similar results were observed for the composite events.

Conclusions

Combined elevated hs-CRP levels and MAIs may increase 1-year stroke risk stratification efficiency in patients with minor ischaemic stroke or TIA compared with using those markers alone, which indicated that the combination of inflammatory and imaging markers might improve the effectiveness of risk stratification concerning minor ischaemic stroke or TIA.

ClinicalTrials.gov Registry (NCT00979589).

Elevated Neutrophil and Presence of Intracranial Artery Stenosis Increase the Risk of Recurrent Stroke

Background and Purpose- The association of neutrophil and intracranial artery stenosis (ICAS) with the prognosis of stroke is uncertain. This study evaluated the relationship between neutrophil levels with and without ICAS and the prognosis of patients with minor stroke or transient ischemic attack. Methods- Data from the CHANCE trial (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events) was reviewed. Patients were divided into 4 groups according to the dichotomy of neutrophil counts and status of ICAS. The primary outcome was a new stroke (ischemic or hemorrhagic), and secondary outcomes included a new composite vascular event (stroke, myocardial infarction, or cardiovascular death) and ischemic stroke. Safety outcome was any hemorrhage at 90 days. The association between neutrophil counts with and without ICAS and risk of any outcome was analyzed by Cox regression models. Results- Of 1034 patients included in this subgroup analysis, 91 had recurrent strokes. Compared with the lower neutrophil levels without ICAS, higher neutrophil levels with ICAS significantly increased the risk of stroke recurrence (adjusted hazard ratio, 2.26; 95% CI, 1.19-4.31; P=0.01) and composite outcome (adjusted hazard ratio, 1.98; 95% CI, 1.06-3.67; P=0.03). However, there was no safety issue. Conclusions- Concomitant presence of higher neutrophil levels and ICAS was associated with the increased risk of stroke recurrence, and combined adverse outcome events in patients already had minor ischemic stroke or high-risk transient ischemic attack. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT00979589.

High neutrophil to lymphocyte ratios predict intracranial atherosclerosis in a healthy population

BACKGROUND AND AIMS

Although atherosclerosis has been shown to be an inflammatory disease, intracranial atherosclerosis (ICAS) has not been well addressed. The purpose of this study was to evaluate the relationship between the neutrophil to lymphocyte ratio (NLR) and the presence of ICAS lesions in a generally healthy population.

METHODS

A consecutive series of subjects, who voluntarily visited for health check-ups between January 2006 and December 2013, were selected. Brain magnetic resonance imaging, brain magnetic angiography (MRA), and blood cell count data were assessed. ICAS was defined as an occlusion or more than 50% stenosis of intracranial vessels, as observed on brain MRA images. NLR was calculated based on absolute neutrophil and lymphocyte counts.

RESULTS

A total of 2842 subjects were evaluated, and 76 ICAS cases were found. The median NLR was 1.52 [1.17-2.01]. In multivariate analysis, NLR remained an independent predictor of ICAS [adjusted OR (aOR) = 1.72, 95% confidence interval (CI) = 1.01-2.95, p = 0.048]. Age (aOR = 1.08, 95% CI = 1.05-1.11, p < 0.001) and hypertension (aOR = 1.81, 95% CI = 1.11-2.94, p = 0.017) were also significant factors for ICAS independent of NLR. Regarding ICAS burdens, NLR was significantly higher when the number of ICAS lesions (p = 0.017) or occlusive ICAS lesions (p = 0.005) was increased in a dose-response manner.

CONCLUSIONS

A high NLR was associated with both prevalence and burdens of ICAS in a healthy population.

Association of Neutrophil/Lymphocyte Ratio with Plaque Morphology in Patients with Asymptomatic Intermediate Carotid Artery Stenosis

Background and Objectives

Non-calcified carotid plaques are more unstable than calcified plaques, and they are associated with a higher risk of rupture, thromboembolism, and consequently, stroke. The purpose of the present study is to compare calcified and non-calcified plaques that cause intermediate carotid artery stenosis with respect to neutrophil/lymphocyte ratio (NLR).

Subjects and Methods

A total number of 139 asymptomatic patients with 50-70% stenosis of the carotid artery were included in this study. Carotid Doppler ultrasound imaging and computed tomography angiography were performed to divide the carotid artery plaques into two groups as calcified and non-calcified. Patients included in the calcified (n=73) and non-calcified (n=66) plaque groups were compared with respect to total neutrophil count, lymphocyte count and NLR.

Results

Total lymphocyte count was statistically significantly lower in the non-calcified plaque group compared to the calcified plaque group (total lymphocyte count in non-calcified/calcified plaque groups [10³/mm³]: 2.1/2.3, respectively) (p=0.002). NLR was statistically significantly higher in the non-calcified plaque group compared to the calcified plaque group (NLR in non-calcified/calcified plaque groups: 2.6/2.1, respectively) (p<0.001). The cut-off value for NLR was found to be >2.54. Multivariate regression analysis showed that NLR was independently associated with non-calcified carotid artery plaques (odds ratio 5.686, 95% CI 2.498-12.944, p<0.001).

Conclusions

NLR is increased in the presence of non-calcified carotid artery plaques that cause asymptomatic intermediate stenosis. Increased NLR can be used as a marker to assess the risk of rupture of non-calcified carotid artery plaques.

Targeting neutrophils in ischemic stroke: translational insights from experimental studies

Neutrophils have key roles in ischemic brain injury, thrombosis, and atherosclerosis. As such, neutrophils are of great interest as targets to treat and prevent ischemic stroke. After stroke, neutrophils respond rapidly promoting blood-brain barrier disruption, cerebral edema, and brain injury. A surge of neutrophil-derived reactive oxygen species, proteases, and cytokines are released as neutrophils interact with cerebral endothelium. Neutrophils also are linked to the major processes that cause ischemic stroke, thrombosis, and atherosclerosis. Thrombosis is promoted through interactions with platelets, clotting factors, and release of prothrombotic molecules. In atherosclerosis, neutrophils promote plaque formation and rupture by generating oxidized-low density lipoprotein, enhancing monocyte infiltration, and degrading the fibrous cap. In experimental studies targeting neutrophils can improve stroke. However, early human studies have been met with challenges, and suggest that selective targeting of neutrophils may be required. Several properties of neutrophil are beneficial and thus may important to preserve in patients with stroke including antimicrobial, antiinflammatory, and neuroprotective functions.

Markers of inflammation associated with plaque progression and instability in patients with carotid atherosclerosis

Atherosclerosis is the focal expression of a systemic disease affecting medium- and large-sized arteries, in which traditional cardiovascular risk factor and immune factors play a key role. It is well accepted that circulating biomarkers, including C-reactive protein and interleukin-6, reliably predict major cardiovascular events, including myocardial infarction or death. However, the relevance of biomarkers of systemic inflammation to atherosclerosis progression in the carotid artery is less established. The large majority of clinical studies focused on the association between biomarkers and subclinical atherosclerosis, that is, carotid intima-media thickening (cIMT), which represents an earlier stage of the disease. The aim of this work is to review inflammatory biomarkers that were associated with a higher atherosclerotic burden, a faster disease progression, and features of plaque instability, such as inflammation or neovascularization, in patients with carotid atherosclerotic plaque, which represents an advanced stage of disease compared with cIMT. The association of biomarkers with the occurrence of cerebrovascular events, secondary to carotid plaque rupture, will also be presented. Currently, the degree of carotid artery stenosis is used to predict the risk of future cerebrovascular events in patients affected by carotid atherosclerosis. However, this strategy appears suboptimal. The identification of suitable biomarkers could provide a useful adjunctive criterion to ensure better risk stratification and optimize management.

Echocardiographic epicardial fat thickness and neutrophil to lymphocyte ratio are novel inflammatory predictors of cerebral ischemic stroke

BACKGROUND

The role of epicardial fat thickness (EFT) in ischemic stroke (IS) has not been previously investigated. The aim of the present study was to evaluate EFT and neutrophil/lymphocyte ratio (NLR) among patients with IS and to examine the relationship between these inflammatory markers and the incidence of IS.

METHODS

The cross-sectional design includes 38 patients with IS and 47 age- and sex-matched healthy controls. Echocardiographic measurement of EFT was conducted according to previously published methods. An automated hematology analyzer was used to generate total and differential leukocyte counts from patient blood samples.

RESULTS

Mean EFT was 4.86 ± .68 mm in the control group and 5.95 ± 1.14 mm in the IS group. EFT was significantly greater in the IS patients in relation to the control group (P < .001). Mean NLR was significantly greater among IS patients in relation to the control group (2.5 ± .6 vs. 1.8 ± .4, P < .001). No significant confounding factors were identified in the data set. Spearman's correlation analysis revealed a mild, but highly significant correlation between EFT and NLR (r = .293, P = .006).

CONCLUSIONS

This study demonstrates for the first time the association between EFT and cerebral IS. Echocardiographic EFT was significantly correlated with NLR. NLR and echocardiographic EFT represent inexpensive and readily available clinical markers that maybe useful in estimating risk of IS.

Genetic and pharmacological modifications of thrombin formation in apolipoprotein e-deficient mice determine atherosclerosis severity and atherothrombosis onset in a neutrophil-dependent manner

BACKGROUND

Variations in the blood coagulation activity, determined genetically or by medication, may alter atherosclerotic plaque progression, by influencing pleiotropic effects of coagulation proteases. Published experimental studies have yielded contradictory findings on the role of hypercoagulability in atherogenesis. We therefore sought to address this matter by extensively investigating the in vivo significance of genetic alterations and pharmacologic inhibition of thrombin formation for the onset and progression of atherosclerosis, and plaque phenotype determination.

METHODOLOGY/PRINCIPAL FINDINGS

We generated transgenic atherosclerosis-prone mice with diminished coagulant or hypercoagulable phenotype and employed two distinct models of atherosclerosis. Gene-targeted 50% reduction in prothrombin (FII(-/WT):ApoE(-/-)) was remarkably effective in limiting disease compared to control ApoE(-/-) mice, associated with significant qualitative benefits, including diminished leukocyte infiltration, altered collagen and vascular smooth muscle cell content. Genetically-imposed hypercoagulability in TM(Pro/Pro):ApoE(-/-) mice resulted in severe atherosclerosis, plaque vulnerability and spontaneous atherothrombosis. Hypercoagulability was associated with a pronounced neutrophilia, neutrophil hyper-reactivity, markedly increased oxidative stress, neutrophil intraplaque infiltration and apoptosis. Administration of either the synthetic specific thrombin inhibitor Dabigatran etexilate, or recombinant activated protein C (APC), counteracted the pro-inflammatory and pro-atherogenic phenotype of pro-thrombotic TM(Pro/Pro):ApoE(-/-) mice.

CONCLUSIONS/SIGNIFICANCE

We provide new evidence highlighting the importance of neutrophils in the coagulation-inflammation interplay during atherogenesis. Our findings reveal that thrombin-mediated proteolysis is an unexpectedly powerful determinant of atherosclerosis in multiple distinct settings. These studies suggest that selective anticoagulants employed to prevent thrombotic events may also be remarkably effective in clinically impeding the onset and progression of cardiovascular disease.

The value of C-reactive protein in symptomatic versus asymptomatic carotid artery stenosis

Inflammatory markers may help establish the diagnosis of carotid atherosclerotic disease and predict the progression and outcomes. We evaluated inflammatory markers in symptomatic and asymptomatic patients with moderate to severe carotid artery stenosis, including high-sensitivity C-reactive protein (hs-CRP), leukocyte count, leukocyte subgroups and erythrocyte sedimentation rate. There were 32 symptomatic and 16 asymptomatic patients (age ≥50 years) with moderate to severe carotid stenosis detected by color Doppler ultrasonography, and 22 individuals without atherosclerotic findings on Doppler ultrasonography. The mean hs-CRP was significantly greater in the symptomatic (p = 0.001) and asymptomatic (p < 0.001) patients than control subjects; there was no significant difference between symptomatic and asymptomatic patients in mean hs-CRP values. Compared with control subjects, asymptomatic patients had greater mean leukocyte count (p = 0.016). Compared with control subjects, symptomatic patients had greater mean neutrophil count (p = 0.012), monocyte count (p = 0.021) and erythrocyte sedimentation rate (p = 0.001). The hs-CRP was associated with moderate to severe carotid artery stenosis, but it did not differentiate symptomatic and asymptomatic patients.

Total and differential leucocyte counts in relation to incidence of stroke subtypes and mortality: a prospective cohort study

OBJECTIVES

Elevated levels of total leucocyte as well as leucocyte subtypes have been associated with increased risk of atherosclerotic disease. Atherosclerosis is an important cause of cerebral infarction, whereas its significance in intracerebral haemorrhage (ICH) is less clear. A small number of prospective studies have revealed the relationship between leucocyte counts and incident stroke, in particular incidence of stroke subtypes. We evaluated the associations between total leucocyte count (TLC) as well as leucocyte subtypes and the incidence of and mortality caused by different stroke subtypes.

DESIGN AND SUBJECTS

Of 28 449 participants from the Malmö Diet and Cancer Study, 26 927 stroke-free subjects (mean age at screening, 58 ± 8 years) were included in a prospective cohort study. The screening period was between 1991 and 1996. Incidence of stroke, 1-year mortality and 1-month case-fatality rate (CFR) were assessed by linkage to local and national registers. Cox regression analysis was used to assess stroke risk and 1-year mortality, and 1-month CFR was assessed by logistic regression analysis.

RESULTS

During a follow-up period of 13.6 ± 3.3 years, 1515 participants had a first-ever stroke (cerebral infarction, n = 1314; ICH, n = 201). After adjustments for other risk factors, TLC and neutrophil count were significantly associated with increased incidence of cerebral infarction (hazards ratio (HR), 1.4; 95% confidence interval (CI), 1.2-1.7 and 1.3; 95% CI, 1.1-1.5, respectively). There was an inverse association between elevated TLC and incident ICH (HR, 0.7; 95% CI, 0.4-0.99). No associations were found between leucocyte counts and mortality for either stroke subtype.

CONCLUSION

The results suggest that the relationships with inflammation for ischaemic stroke and ICH are different.