Inflammatory mediators and cerebral embolism in carotid stenting: new markers of risk

Factors Associated with High-Risk Plaque Characteristics Among Patients with Medium to Severe Carotid Artery Stenosis

BACKGROUND

There has been a large discussion in literature regarding the proper management of asymptomatic patients with significant carotid artery stenosis. This study aims to identify potential risk factors associated with high-risk carotid plaques.

METHODS

This is a retrospective study based on a prospective database. Eligible patients had medium to severe symptomatic or asymptomatic carotid stenosis (≥50%, North American Symptomatic Carotid Endarterectomy Trial criteria). This study will analyze patients recruited by our institution as part of the multicenter TAXINOMISIS project (NCT03495830). According to protocol, all patients underwent a colored Duplex ultrasound examination and a magnetic resonance angiography at baseline. Carotid plaques were classified according to Gray-Weale ultrasonographic criteria (types I-V). Main outcomes included the occurrence of symptoms, the high/low echogenicity of the plaque, the existence of intraplaque hemorrhage and the existence of lipidic/necrotic core. Secondary, risk factors associated with the aforementioned outcomes were evaluated.

RESULTS

A total of 62 patients (mean age: 68.7 ± 9.3 years, 66.1% males, 24.2% symptomatic) were recruited by our department. Mean carotid stenosis was 70.81% ± 13.53%. In multivariate regression analysis, C-reactive protein > 2 mg/l was strongly associated with symptomatic stenosis (odds ratio [OR] = 9.92 [1.12-88.178]; P = 0.039), and low high-density lipoprotein levels (<1200 mmol/l) were associated with lipidic/necrotic plaque core (OR = 16.88 [1.10-259.30]; P = 0.043). Low high-density lipoprotein levels (OR = 7.22 [1.00-51.95], P = 0.049) and HbA1c >7% (OR = 0.08 [0.01-0.93], P = 0.044) were associated with type III/IV plaques whereas HgAbc1 >7% (OR = 14.26 [1.21-168.34], P = 0.035) was associated with type V plaques.

CONCLUSIONS

This preliminary study has revealed some potential risk factors associated with unstable carotid plaques. These data could help the future development of prognostic models for early detection patients that could benefit from further intervention.

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.

Current Biomarkers for Carotid Artery Stenosis: A Comprehensive Review of the Literature

Carotid artery stenosis (CAS), an atherosclerotic disease of the carotid artery, is one of the leading causes of transient ischemic attacks (TIA) and cerebrovascular attacks (CVA). The atherogenic process of CAS affects a wide range of physiological processes, such as inflammation, endothelial cell function, smooth muscle cell migration and many more. The current gold-standard test for CAS is Doppler ultrasound; however, there is yet to be determined a strong, clinically validated biomarker in the blood that can diagnose patients with CAS and/or predict adverse outcomes in such patients. In this comprehensive literature review, we evaluated all of the current research on plasma and serum proteins that are current contenders for biomarkers for CAS. In this literature review, 36 proteins found as potential biomarkers for CAS were categorized in to the following nine categories based on protein function: (1) Inflammation and Immunity, (2) Lipid Metabolism, (3) Haemostasis, (4) Cardiovascular Markers, (5) Markers of Kidney Function, (6) Bone Health, (7) Cellular Structure, (8) Growth Factors, and (9) Hormones. This literature review is the most up-to-date and current comprehensive review of research on biomarkers of CAS, and the only review that demonstrated the several pathways that contribute to the initiation and progression of the disease. With this review, future studies can determine if any new markers, or a panel of the proteins explored in this study, may be contenders as diagnostic or prognostic markers for CAS.

A single-center pilot randomized controlled trial of atorvastatin loading for preventing ischemic brain damage after carotid artery stenting

Objective

Carotid artery stenting (CAS) performed perioperatively with high-dose atorvastatin may reduce the incidence of new ischemic brain lesions, but more high-level evidence is needed. Furthermore, the optimal dose and course of perioperative statin therapy remain uncertain.

Methods

A single-center, prospective, parallel controlled, pilot randomized clinical trial was conducted at Beijing Hospital. The study includes a total of 130 patients with CAS. The patients were randomly assigned to receive a high-dose of 80 mg/day atorvastatin (n = 65) or a standard-dose of 20 mg/day atorvastatin (n = 65) 3 days before and 3 days after planned CAS. The primary endpoint event was the cumulative incidence of silent new ischemic cerebral lesions (sNICL) on post-CAS cerebral diffusion-weighted magnetic resonance imaging (DW-MRI), transient ischemic attack (TIA), or ischemic stroke within 30 days after CAS.

Results

Among the 130 patients, 123 completed the study, of which 63 were in the high-dose group and 60 were in the standard-dose group. The incidence of major endpoint events was 69.8% (44 cases) and 78.3% (46 cases) in the high-dose and standard-dose groups, respectively. There was no significant difference between the two groups (HR, 0.705; 95% CI, 0.315-1.576; p = 0.393). According to the stratified analysis results, the sNICL incidence was significantly different between the two groups in the symptomatic patients (HR, 0.263; 95% CI, 0.70-0.984; p = 0.04).

Conclusion

Among patients with CAS, a periprocedural high-dose of atorvastatin did not reduce the rate of periprocedural ischemic brain damage. However, high-dose statins can reduce the incidence of sNICL after CAS in patients with symptomatic carotid stenosis.

Clinical Trial Registration

Clinicaltrials.gov, identifier NCT03079115.

Leukocyte Count Predicts Carotid Artery Stenosis in Men with Ischemic Stroke: Sub Study of the Preventive Antibiotics in Stroke Study (PASS)

Background: Inflammation is important in the development of atherosclerosis. Research suggested sex-dependent differences for the value of inflammatory markers for risk stratification of stroke patients with internal carotid artery stenosis (ICAS). We investigated whether leukocytes and thrombocytes were associated with ≥50% ICAS in acute stroke and whether this was sex-dependent. Patients included in the Preventive Antibiotics in Stroke Study (PASS) were used. PASS is a randomized controlled trial that randomized between four days of preventive ceftriaxone intravenously or standard stroke care alone. It investigated whether ceftriaxone could improve functional outcome at three months after stroke. Methods: Patients included in PASS were evaluated for the predictive value of leukocytes and thrombocytes for ICAS. Ischemic stroke and TIA patients were selected out of PASS patients. Logistic regression analysis was performed adjusting for NIHSS and other covariates. Results: 2550 patients were included in PASS. 1413 of 2550 patients (55%) were evaluated in this sub study. Female patients showed a mean of 8.55 × 10⁹/L for leukocytes and 259 × 10⁹/L for thrombocytes. Men showed a mean of 8.29 × 10⁹/L for leukocytes and 224 × 10⁹/L for thrombocytes. Multivariate logistic regression analysis showed that leukocytes were independently associated with ICAS ≥ 50% in male patients (OR 1.094, p = 0.008), but not in female patients (OR 1.041, p = 0.360). Thrombocytes were not associated with ICAS. Conclusions: We conclude that blood leukocyte count independently predicts ICAS in men after acute stroke, but not in women. Clinical Trial unique identifier: ISRCTN66140176.

Biomarkers in unstable carotid plaque: Physiopathology and Prediction

AIMS

To study the role of cytokines and vascular inflammatory biomarkers in unstable carotid plaque.

BACKGROUND

Clinical studies showed that not only the degree of stenosis but also the type of carotid plaque can be responsible for ipsilateral ischemic stroke.

OBJECTIVE

The objective of this study is to suggest a role for vulnerable carotid atherosclerotic disease in the occurrence of ischemic stroke.

METHODS

PubMed, Embase, Cochrane library, and reference lists have been used to evaluate articles published until February 15, 2021.

RESULTS

Several factors may be involved in unstable plaque. Clinical studies support the involvement of brain inflammatory biomarkers as well as cytokines in the unstable carotid plaque.

CONCLUSIONS

Biomarkers could help to stratify patients with a vulnerable carotid plaque and to personalize the drug treatment. In this review, we briefly discuss the characteristics of vulnerable plaque and the role of biomarkers in the vulnerable carotid plaque.

Association between high sensitivity C-reactive protein (hs-CRP) levels and the risk of major adverse cardiovascular events (MACE) and/or microembolic signals after carotid angioplasty and stenting

Background

To evaluate the association between pre/post-procedural high sensitive C-reactive protein (hs-CRP) level and hs-CRP difference, and the risk of major adverse cardiovascular events (MACE) or new diffusion-weighted MRI lesions after carotid angioplasty and stenting (CAS).

Methods

In this study, conducted in 2016 in Shiraz (Iran), patients who underwent diagnostic angiography and CAS were recruited. CAS was performed with distal embolic protection device on patients with both standard and high risk of endarterectomy. Pre/post-procedural hs-CRP, and hs-CRP difference were determined by immunoenzymometric assay method.

Results

A total of 50 patients with diagnostic angiography and 60 patients with CAS were enrolled. No death, myocardial infarction, ischemic or hemorrhagic stroke, and need to revascularization occurred during the 30-days of the post-procedural period. Accordingly, the statistical evaluation in associating MACE and hs-CRP levels was impossible. Angioplasty was associated with higher frequency of elevated post-procedural hs-CRP in comparison to angiography (P=0.003). The higher age, symptomatic lesions, negative history of hypertension, and hs-CRP difference had significant association with the presence of new DWI lesions in univariate analysis (all P<0.05). Angioplasty of left carotid bulb and post-procedural hs-CRP levels was very close to the level of significance (P=0.06). But only left sided lesions had positive association (P=0.037) and hypertension had negative association (P=0.037) in multivariate regression analysis. There were significant association between post-procedural hs-CRP level (P=0.02) and hs-CRP difference (P=0.003), and the number of new lesions; and the hs-CRP difference and the accumulated lesion surface area (P=0.009).

Conclusion

Post-procedural hs-CRP and hs-CRP difference may predict embolic complications of CAS.

Review of serum biomarkers in carotid atherosclerosis

BACKGROUND

Carotid artery atherosclerotic stenosis is a preventable major cause of stroke, but there is still a need for definition of high-risk plaque in asymptomatic patients who might benefit from interventional therapies. Several image markers are recommended to characterize unstable plaques. The measurement of serum biomarkers is a promising method to assist in decision making, but the lack of robust evidence in the carotid environment burdens their potential as a standard of care. The goal of this review was to offer an updated state-of-the-art study of available serum biomarkers with clinical implications, with focus on those that may predict carotid symptom development.

METHODS

The Cochrane Library and MEDLINE databases were searched (all until September 2018) for studies on carotid plaque and serum biomarkers of atherosclerosis. Nonhuman, basic science, and histology studies were excluded, focusing on clinical studies. Selected abstracts were screened to include the most relevant articles on atherosclerotic plaque presence, progression, instability or symptom development.

RESULTS

Some well-established biomarkers for coronary disease are not relevant to carotid atherosclerosis and other inflammatory biomarkers, lipids, interleukins, homocysteine, and adipokines may be useful in quantifying carotid disease-related risk. Some serum biomarkers combined with image features may assist vascular specialists in selecting patients at high risk for stroke and in need of intervention.

CONCLUSIONS

Prospective studies applying a combination of biomarkers are essential to prove clinical usefulness.

Silent brain infarcts on diffusion-weighted imaging after carotid revascularisation: A surrogate outcome measure for procedural stroke? A systematic review and meta-analysis

Aim

To investigate whether lesions on diffusion-weighted imaging (DWI+) after carotid artery stenting (CAS) or endarterectomy (CEA) might provide a surrogate outcome measure for procedural stroke.

Materials and Methods

Systematic MedLine® database search with selection of all studies published up to the end of 2016 in which DWI scans were obtained before and within seven days after CAS or CEA. The correlation between the underlying log odds of stroke and of DWI+ across all treatment groups (i.e. CAS or CEA groups) from included studies was estimated using a bivariate random effects logistic regression model. Relative risks of DWI+ and stroke in studies comparing CAS vs. CEA were estimated using fixed-effect Mantel-Haenszel models.

Results

We included data of 4871 CAS and 2099 CEA procedures (85 studies). Across all treatment groups (CAS and CEA), the log odds for DWI+ was significantly associated with the log odds for clinically manifest stroke (correlation coefficient 0.61 (95% CI 0.27 to 0.87), p = 0.0012). Across all carotid artery stenting groups, the correlation coefficient was 0.19 (p = 0.074). There were too few CEA groups to reliably estimate a correlation coefficient in this subset alone. In 19 studies comparing CAS vs. CEA, the relative risks (95% confidence intervals) of DWI+ and stroke were 3.83 (3.17-4.63, p < 0.00001) and 2.38 (1.44-3.94, p = 0.0007), respectively.

Discussion

This systematic meta-analysis demonstrates a correlation between the occurrence of silent brain infarcts on diffusion-weighted imaging and the risk of clinically manifest stroke in carotid revascularisation procedures.

Conclusion

Our findings strengthen the evidence base for the use of DWI as a surrogate outcome measure for procedural stroke in carotid revascularisation procedures. Further randomised studies comparing treatment effects on DWI lesions and clinical stroke are needed to fully establish surrogacy.

The effects of fast-track surgery on inflammation and immunity in patients undergoing colorectal surgery

OBJECTIVE

The objective of this study is to explore the effects of the fast-track surgery (FTS) program on inflammation and immunity in patients undergoing colorectal surgery.

METHODS

From August 2014 to March 2015, a prospective and randomized controlled trial of 230 patients who underwent colorectal surgery was performed. The patients were randomly assigned to an FTS group (116 patients) or a traditional group (114 patients). Inflammatory mediators, immunological indicators, postoperative recovery indexes, and complications were compared between the two groups.

RESULTS

The inflammatory mediators (CRP, IL-6, TNF-α) were lower in the FTS group than in the traditional group (P < 0.05) on postoperative day (POD) 1, POD 4, and POD 6, and the immunological indicators (IgG, IgA, C3, C4) of the FTS group were superior to those of the traditional group (P < 0.05) on POD 4 and POD 6. The time to first aerofluxus, defecation, oral intake, and ambulation after surgery was shorter in the FTS group than in the traditional group (P < 0.05); however, the duration of postoperative hospitalization did not differ significantly between the two groups (P > 0.05). The total complications were significantly lower in the FTS group than in the traditional group (P < 0.05).

CONCLUSION

The FTS program can decrease inflammation, maintain immune homeostasis, and improve rehabilitation effects in colorectal surgery patients.

The relationship between preoperative serum cortisol level and the stability of plaque in carotid artery stenosis patients undergoing carotid endarterectomy

BACKGROUND

Stability of plaque has been implicated as risk factor for stroke. Serum cortisol regulates lipoprotein metabolism and immune response, contributing to plaque stability in atherosclerosis. However, the relationship between serum cortisol and stability of carotid plaque has not been well characterized. We conducted a serology analysis to identify the relationship between serum cortisol and carotid plaque stability.

METHODS

Between May 2013 to October 2015, 73 patients with carotid stenosis patients undergoing carotid endarterectomy (CEA) were enrolled in our study. Serum cortisol was analyzed at 8:00 AM in the morning before surgery via liquid chromatography tandem mass spectrometry. According to the classification made by the American Heart Association, hematoxylin-and-eosin staining was performed to divide these patients into either a stable or unstable group, according to the morphology of fibrous cap, lipid core and intima layer. A curve fitting method was used to identify the relationship between preoperative serum cortisol and stability of carotid plaque. Univariate and multivariate logistic regression analysis were used to identify carotid plaque stability-associated serum cortisol.

RESULTS

Curve fitting's result represents a U-shape characteristic. A total of 314.92 and 395.23 nmol/L were considered as the cut point for preoperative serum cortisol when trisected the patients. When adjusted for degree of stenosis, hyperlipemia, smoking and low-density lipoprotein (LDL), univariate and multivariate logistic regression analysis' results demonstrated that preoperative serum cortisol can significantly affect carotid plaque stability. The odds ratio values in multivariate logistic regression analysis for C reactive protein (CRP), white blood cell (WBC), interleukin-6 (IL-6) and preoperative serum cortisol level were 7.67 and 20.86 respectively.

CONCLUSIONS

Preoperative serum cortisol was associated with stability of carotid plaque in patients undergoing CEA. Low or high levels of preoperative serum cortisol might be an adverse factor for carotid plaque stability.

Association of thrombelastographic parameters with post-stenting ischemic events

BACKGROUND AND PURPOSE

Thrombelastography (TEG) is widely used for the measurement of platelet function. However, few studies have investigated the TEG parameters in patients receiving extracranial or intracranial artery stenting for ischemic cerebrovascular disease. This study sought to describe the association of TEG parameters before the procedure with post-procedural ischemic events after extracranial or intracranial artery stenting.

METHODS

Patients in whom stenting was performed for extracranial or intracranial artery stenosis (70-99%) were recruited into the study. Blood samples were obtained for TEG to assess platelet function before stenting. The primary endpoint was ischemic stroke or transient ischemic attack in the territory of the stented artery.

RESULTS

A total of 218 patients were included in the study. During a mean follow-up period of 132 days (range 98-226 days), 18 (8.3%) primary endpoint events were recorded. Compared with patients without ischemic events, the ADP-induced platelet-fibrin clot strength (MA_ADP) was significantly higher (41.57±15.10 vs 33.50±13.86, p=0.020) and the ADP inhibition rate (ADP%) was significantly lower in patients with ischemic events (39.54±23.15 vs 55.29±24.43, p=0.009). Multivariate analysis identified MA_ADP and ADP% as significant independent predictors of subsequent ischemic events with HRs of 1.036 and 0.965, respectively. From receiver operating characteristic curve analysis, MA_ADP >49.95 mm had the best predictive value of ischemic events.

CONCLUSIONS

Our study suggests that TEG parameters MA_ADP and ADP% are associated with subsequent ischemic events in patients with extracranial or intracranial stents.

CLINICAL TRIAL NUMBER

NCT01925872.

Preoperative evaluation of the vascular surgery patient

Patients undergoing vascular surgery present a myriad of perioperative challenges due to the complex comorbidities affecting them in conjunction with high-risk surgical procedures. Additionally, advances in endovascular technology have enabled surgical procedures to be performed on patients who would not have been considered surgical candidates in the past. This combination of increasing patient morbidity and evolving surgical technique requires a well-planned preoperative assessment and close communication with surgical and perioperative colleagues. This article outlines an appropriate approach by first considering each organ system, followed by review of considerations unique to various surgical procedures, and then an overall assessment of risk.