Comparison between early and late carotid endarterectomy for symptomatic carotid stenosis in relation to oxidized low-density lipoprotein and plaque vulnerability

OxLDL as a prognostic biomarker of plaque instability in patients qualified for carotid endarterectomy

Atherosclerotic plaque instability increases the risk of stroke. As such, determining the nature of an instability atherosclerotic plaque may speed up qualification for carotid endarterectomy (CEA), thus reducing the risk of acute vascular events. The aim of the study was to determine the diagnostic value of oxidized LDL cholesterol (ox-LDL), matrix metalloproteinase 9 (MMP-9) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in serum as a prognostic markers of instability atherosclerotic plaques. Serum was collected from 67 patients who underwent CEA in accordance with the qualification criteria. The levels of ox-LDL, MMP-9 and 8-OHdG were assessed by ELISA. The predictive value of the markers was determined based on an ROC curve, and the cut-off points with the highest sensitivity and specificity were determined. Patients with unstable atherosclerotic plaque had significantly higher serum ox-LDL, MMP-9 and 8-OHdG values. It was found that in patients before CEA, ox-LDL >31.4 ng/mL was associated with an 82.5% probability of unstable atherosclerotic plaque, MMP-9 >113.1 ng/mL with 78.6%, and 8-OHdG >2.15 ng/mL with 64.7%. Multivariate regression analysis found ox-LDL to be an independent factor associated with plaque instability. Patients with unstable plaques tend to have higher serum levels of ox-LDL, MMP-9 and 8-OHdG compared to those with stable plaques. The optimal cut-off point for ox-LDL (AUC 0.86, p <0.0001) was 31.14 ng/mL, with 91.18% sensitivity and 78.79% specificity. The high sensitivity and specificity of ox-LDL suggests that it can be used as an independent marker of plaque instability.

Timing of Carotid Intervention in Symptomatic Carotid Artery Stenosis: A Systematic Review and Meta-Analysis

OBJECTIVE

This review aimed to analyse the timing of carotid endarterectomy (CEA) and carotid artery stenting (CAS) after the index event as well as 30 day outcomes at varying time periods within 14 days of symptom onset.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-analysis statement, comprising an online search of the Medline and Cochrane databases. Methodical quality assessment of the included studies was performed. Endpoints included procedural stroke and/or death stratified by delay from the index event and surgical technique (CEA/CAS).

RESULTS

Seventy-one studies with 232 952 symptomatic patients were included. Overall, 34 retrospective analyses of prospective databases, nine prospective, three RCT, three case control, and 22 retrospective studies were included. Compared with CEA, CAS was associated with higher 30 day stroke (OR 0.70; 95% CI 0.58 - 0.85) and mortality rates (OR 0.41; 95% CI 0.31 - 0.53) when performed ≤ 2 days of symptom onset. Patients undergoing CEA/CAS were analysed in different time frames (≤ 2 vs. 3 - 14 and ≤ 7 vs. 8 - 14 days). Expedited CEA (vs. 3 - 14 days) presented a sampled 30 day stroke rate of 1.4%; 95% CI 0.9 - 1.8 vs. 1.8%; 95% CI 1.8 - 2.0, with no statistically significant difference. Expedited CAS (vs. 3 - 14 days) was associated with no difference in stroke rate but statistically significantly higher mortality rate (OR 2.76; 95% CI 1.39 - 5.50).

CONCLUSION

At present, CEA is safer than transfemoral CAS within 2/7 days of symptom onset. Also, considering absolute rates, expedited CEA complies with the accepted thresholds in international guidelines. The ideal timing for performing CAS (when indicated against CEA) is not yet defined. Additional granular data and standard reporting of timing of intervention will facilitate future monitoring.

Using Serum Biomarkers for Identifying Unstable Carotid Plaque: Update of Current Evidence

Carotid atherosclerosis is responsible for a great proportion of ischemic strokes. Early identification of unstable or vulnerable carotid plaques, and therefore, of patients at high risk for stroke, is of significant medical and socioeconomical value. We reviewed the current literature and discussed the potential role of the most important serum biomarkers in identifying patients with carotid atherosclerosis who are at high risk for atheroembolic stroke.

Association of Plasma Marker of Oxidized Lipid with Histologic Plaque Instability in Patients with Peripheral Artery Disease

BACKGROUND

The association between oxidized low-density lipoprotein (OxLDL) and plaque instability in coronary and carotid artery disease is well established. However, the association between OxLDL and the histologic changes of plaque in peripheral artery disease has not been clearly elucidated. This study aims to investigate the association between plasma OxLDL and histologic plaque instability in patients with peripheral artery disease.

METHODS

Prospectively obtained plaques from 48 patients who underwent endovascular atherectomy (n = 20), surgical endarterectomy (n = 9), or bypass surgery (n = 19) for treatment of atherosclerotic femoropopliteal artery disease were evaluated for histologic fibrosis, sclerosis, calcification, necrosis, cholesterol cleft, and foamy macrophages using hematoxylin and eosin, oil red O, and immunohistochemical staining. Unstable plaques were defined as plaques that were positive for foamy macrophages and with lipid content of more than 10% of the total plaque area. Plasma OxLDL levels were measured using an enzyme-linked immunosorbent assay (Mercodia AB, Uppsala, Sweden).

RESULTS

Of the 48 patients, 26 (54%) had unstable plaques. The unstable plaque group was younger, had fewer angiographic total occlusions, less calcification, and more CD68-positive and LOX-1-positive cells than the stable plaque group. Plasma OxLDL levels were significantly higher in the unstable plaque group than in the stable plaque group (57.4 ± 13.9 vs. 47.2 ± 13.6 U/L, P = 0.014). Multivariate analysis revealed that plasma OxLDL level, smoking, angiographic nontotal occlusion, and statin nonuse were independent predictors of unstable plaque.

CONCLUSIONS

Among patients with peripheral artery disease, the histologic instability of femoropopliteal plaque was independently associated with high plasma OxLDL, smoking, nontotal occlusion, and statin nonuse. Further large-scale studies are necessary to evaluate the role of noninvasive OxLDL measurement for predicting plaque instability and future adverse vascular event.

Research Progress on the Risk Factors and Outcomes of Human Carotid Atherosclerotic Plaques

Objective:

Atherosclerosis is an inflammatory process that results in complex lesions or plaques that protrude into the arterial lumen. Carotid atherosclerotic plaque rupture, with distal atheromatous debris embolization, causes cerebrovascular events. This review aimed to explore research progress on the risk factors and outcomes of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention.

Data Sources:

We searched the PubMed database for recently published research articles up to June 2016, with the key words of “risk factors”, “outcomes”, “blood components”, “molecular mechanisms”, “cellular mechanisms”, and “human carotid atherosclerotic plaques”.

Study Selection:

The articles, regarding the latest developments related to the risk factors and outcomes, atherosclerotic plaque composition, blood components, and consequences of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention, were selected.

Results:

This review described the latest researches regarding the interactive effects of both traditional and novel risk factors for human carotid atherosclerotic plaques, novel insights into human carotid atherosclerotic plaque composition and blood components, and consequences of human carotid atherosclerotic plaque.

Conclusion:

Carotid plaque biology and serologic biomarkers of vulnerability can be used to predict the risk of cerebrovascular events. Furthermore, plaque composition, rather than lesion burden, seems to most predict rupture and subsequent thrombosis.

Comparison of stent free cell area and cerebral lesions after unprotected carotid artery stent placement

OBJECTIVE

This study evaluates the correlation between closed, semi-closed and open-cell stent design and the association between stent type and clinical outcome as well as magnetic resonance imaging (MRI) findings.

DESIGN

A total of 194 patients who underwent unprotected carotid artery stenting (CAS) as well as diffusion-weighted magnetic resonance imaging (DW-MRI) before and after intervention were retrospectively reviewed.

MATERIALS AND METHODS

Three stent designs were studied: closed cell, semi-closed cell and open cell. Spearman's Rho test was performed between the stent free cell area and the number and area of ischaemic lesions found after intervention. Adverse events were evaluated.

RESULTS

There was no significant difference in clinical outcome between the three stent groups (Zilver, Cook Europe, Denmark; Smart, Codman, MA; and Wallstent, Stryker, MN, USA). A significant correlation was found between the stent free cell area and the number and area of new ischaemic lesions on DW-MRI (P = 0.023). There were significantly fewer new lesions with an open-cell design (Zilver; 12.76 mm(2) free cell area) than with a closed-cell design (Wallstent; 1.08 mm(2) free cell area).

CONCLUSIONS

Open-cell stent was related to a lower number and area of silent cerebral ischaemic lesions after unprotected CAS. However, clinical outcome, measured by incidence of adverse events and clinical neurologic assessment, was not significantly different between patients with different stent designs.

Plaque rupture is a determinant of vascular events in carotid artery atherosclerotic disease: involvement of matrix metalloproteinases 2 and 9

BACKGROUND AND PURPOSE

Unstable carotid atherosclerotic plaques are characterized by cap rupture, leading to thromboembolism and stroke. Matrix metalloproteinases (MMPs) have been implicated in the progression of atherosclerosis and plaque rupture. The aim of this study was to assess the relationship between the expressions of MMP-2 and MMP-9 and carotid plaque instability.

METHODS

Eighty atherosclerotic plaques were collected from 74 patients undergoing carotid endarterectomy. Clinical information was obtained from each patient, and plaque morphology was examined at the macroscopic and microscopic levels. The immunohistochemical expressions of MMPs were graded using semiquantitative scales.

RESULTS

Macroscopic ulceration (84.6% versus 63.4%, p=0.042) and microscopic cap rupture (79.5% versus 51.2%, p=0.010) were more common in symptomatic than in asymptomatic patients. Immunoreactivities of MMP-2 and MMP-9 were increased in 40 and 36 atheromatous plaques, respectively. Macroscopic ulceration was strongly correlated with the expressions of MMP-2 (p<0.001) and MMP-9 (p=0.001). There were significant correlations between increased MMP-2 expression and cap rupture (p=0.002), intraplaque hemorrhage (p=0.039), and a thin fibrous cap (p=0.002), and between increased MMP-9 expression and cap rupture (p=0.010) and a large lipid core (p=0.013).

CONCLUSIONS

Plaque rupture was significantly associated with the development of vascular events in carotid atherosclerotic disease. MMP-2 and MMP-9 are strongly correlated with plaque instability.

Systematic Review of the Operative Risks of Carotid Endarterectomy for Recently Symptomatic Stenosis in Relation to the Timing of Surgery

Background and Purpose— Reliable data on the risk of carotid endarterectomy (CEA) in relation to timing of surgery are necessary to plan CEA most effectively, to adjust risks for case-mix, and to understand the mechanisms of operative stroke.

Methods— We performed a systematic review of all studies published from 1980 to 2008 inclusive that reported the risk of stroke and death due to CEA in relation to the time between presenting symptom and surgery. Pooled estimates of risk by the time since the last event were obtained by Mantel–Haenszel meta-analysis.

Results— Of 494 published operative series, only 47 stratified risk by timing of surgery. The pooled absolute risks of stroke and death after urgent CEA were high in patients with stroke-in-evolution (20.2%, 95% CI 12.0 to 28.4) and in patients with crescendo TIA (11.4%, 6.1 to 16.7), with no trends toward reduced risks in more recent studies. However, there was no significant difference between early and later CEA in neurologically stable patients with recent TIA or nondisabling stroke (<1 week versus ≥1 week, OR=1.2, 0.9 to 1.7, P =0.17; <2 weeks versus ≥2 weeks, OR=1.2, 0.9 to 1.6, P =0.13).

Conclusions— Emergency endarterectomy for stroke-in-evolution has a high operative risk, but the risk may be somewhat lower in patients with crescendo TIA. Surgery in the first week in neurologically stable patients with TIA or minor stroke is not associated with a substantially higher operative risk than delayed surgery. More data are required on the risk and benefit of more urgent surgery for TIA and minor stroke and for early versus delayed surgery in patients with major nondisabling stroke.