C-reactive protein is elevated in symptomatic compared with asymptomatic patients with carotid artery disease

Plasma C-reactive protein is associated with a pro-inflammatory and adverse plaque phenotype

BACKGROUND AND AIMS

Systemic low-grade inflammation, measured by plasma high-sensitivity C-reactive protein (hsCRP) levels, is an important risk factor for atherosclerotic cardiovascular disease (ASCVD). To date, however, it is unknown whether plasma hsCRP is associated with adverse histological plaque features.

METHODS

Plaques were derived during carotid endarterectomy. Patients with hsCRP levels ≥2 mg/L were evaluated for pro-inflammatory and adverse plaque characteristics, as well as future ASCVD events, and compared with patients with low hsCRP levels. Logistic and linear regression analyses in addition to subdistribution hazard ratios were conducted, adjusted for cardiovascular risk factors.

RESULTS

A total of 1096 patients were included, of which 494 (46.2 %) had hsCRP levels ≥2 mg/L. Elevated hsCRP levels 2 mg/L were independently associated with levels of plaque interleukin 6, beta coefficient of 109.8 (95 % confidence interval (CI): 33.4, 186.5; p = 0.005) pg/L, interleukin 8 levels, 194.8 (110.4, 378.2; p = 0.03) pg/L and adiponectin plaque levels, -16.8 (-30.1, -3.6; p = 0.01) μg/L, compared with plaques from patients with low hsCRP levels. Histological analysis revealed increased vessel density in high hsCRP patients, odds ratio (OR) of 1.57 (1.20, 2.09; p = 0.001), larger lipid core, 1.35 (1.02, 1.73; p = 0.04), and increased macrophage content, 1.32 (1.02, 1.73; p = 0.04). Over a 3-year follow-up period, hsCRP levels ≥2 mg/L were associated with a hazard ratio of 1.81 (1.03, 3.16; p = 0.04) for coronary artery disease event risk.

CONCLUSIONS

The distinct inflammatory and histological features observed in carotid plaques among individuals with hsCRP levels ≥2 mg/L underscore the utility of plasma hsCRP as a potent identifier for patients harboring high-risk plaques.

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

PURPOSE

To investigate serological predictors of risk for cerebral embolism after carotid artery stenting (CAS).

METHODS

Twenty consecutive symptomatic and asymptomatic patients (13 men; mean age 74 years) with carotid artery stenosis undergoing standardized filter-protected CAS (Wallstent) were preoperatively evaluated to identify unstable plaque (duplex ultrasound), complicated aortic plaque (transesophageal echocardiography), and inflammatory status [high-sensitivity C-reactive protein (hs-CRP) and serum amyloid-A protein (SAA) serum levels]. Aortic arch type, carotid tortuosity, and complexity of the procedure were considered. Cerebral embolism was evaluated by comparing the number, volume, and side (ipsilateral and non-ipsilateral) of preoperative and postoperative cerebral lesions detected on diffusion-weighted resonance magnetic imaging (DW-MRI) and through light and scanning electron microscopy analysis of cerebral protection filters obtained from CAS.

RESULTS

All CAS procedures were completed with no complications. All patients had a negative preoperative DW-MRI, but at least 1 asymptomatic cerebral lesion appeared on DW-MRI after the procedure in 18 (90%) patients. Female gender was associated with a higher number of cerebral lesions (18.2±10.9 vs. 8.3±8.8 for men, p=0.03). Carotid plaque morphology, supra-aortic vessel anatomy, and procedure complexity did not correlate with number or volume of new cerebral lesions. Complicated aortic plaque was associated with a higher volume of non-ipsilateral cerebral lesions than uncomplicated plaque (235.0±259.3 vs. 63.6±63.2 mm(3), respectively; p=0.02). Hs-CRP ≥5 mg/L and SAA ≥10 mg/L were significantly associated with a higher number of new cerebral lesions [16.2±10.7 vs. 4.3±3.4 for hs-CRP <5 mg/L (p=0.02) and 14.8±10.3 vs. 2.8±3.4 for SAA <10 mg/L (p=0.006), respectively]. Hs-CRP ≥5 mg/L and SAA ≥10 mg/L also correlated with greater surface involvement by embolic materials in the protection filters at microscopic analysis [37.0% (5.1%) vs. 26.9% (2.5%) for hs-CRP <5 mg/L, p=0.004; 35.9% (13.5%) vs. 22.2% (6.9%) for SAA <10 mg/L, p=0.02].

CONCLUSION

In addition to female gender and the presence of complicated aortic plaque, inflammatory status can be a predictor of cerebral embolism in CAS.

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.

Carotid wall thickness and stroke risk in patients with asymptomatic internal carotid stenosis

OBJECTIVE

Aim of this study was to investigate if the risk of stroke and other vascular diseases can be predicted in subjects with severe asymptomatic carotid artery stenosis on the basis of carotid wall thickness evaluation.

METHODS

We included 162 consecutive subjects with asymptomatic internal carotid artery stenosis of 60% or greater reduction in diameter. Demographic characteristics, vascular risk factors, therapy, degree of carotid stenosis and carotid intima-media thickness (IMT) were detailed for all subjects. Subjects were prospectively evaluated for a median period of 35 months (min=10, max=47). Outcome measures were: the occurrence of ischemic stroke ipsilateral to carotid stenosis and any other vascular event.

RESULTS

Thirty subjects (18.5%) suffered a vascular event: 16 (53%) myocardial infarctions and 14 (47%) strokes. Older age and higher IMT values were the only factors significantly associated with the risk of vascular events. The hazard ratio (adjusted for age, sex and other risk factors) for each 0.1 mm of IMT increase resulted 1.30 (95% CI: 1.14, 1.18) for combined vascular events, 1.47 for cerebrovascular events (95% CI: 1.16, 1.87) and 1.24 (95% CI: 1.09, 1.42) for cardiovascular events. Values of IMT above 1.15 mm increased the risk of having a stroke 19 times and the risk of having a myocardial infarction two times.

CONCLUSIONS

An increased carotid wall thickness can be considered as a marker of an increased risk of vascular events in asymptomatic subjects with internal carotid artery stenosis>60%. Highest IMT values are able to identify subjects with specific stroke risk. This information could be of interest to recognize subjects who might benefit most from surgical or revascularization procedures.

Markers of inflammation in patients with symptomatic and asymptomatic carotid artery stenosis: a case-control study

OBJECTIVES

There is evidence that inflammation plays a role in the pathogenesis of atherosclerosis. We compared levels of inflammatory markers between patients undergoing carotid endarterectomy (CEA) and controls, and between patients with symptomatic and asymptomatic internal carotid artery (ICA) stenosis.

MATERIALS AND METHODS

A total of 180 patients with ICA stenosis were compared with 180 age-matched and sex-matched controls. The biomarkers evaluated were high-sensitivity C-reactive protein (hs-CRP), soluble intercellular adhesion molecule 1, soluble vascular cell adhesion molecule 1 (sVCAM-1), and interleukin-6 (IL-6).

RESULTS

The levels of hs-CRP, sVCAM-1, and IL-6 in the CEA group were significantly higher than in the control group (1.87 mg/mL vs 1.44 mg/mL, P = .011; 1408 ng/dL vs 672 ng/dL, P < .001; 11.9 pg/mL vs 6.3 pg/mL, P < .001). Multivariate linear regression analysis, adjusted for all clinical and physiologic parameters, showed a significant association between ICA stenosis and hs-CRP, sVCAM-1, and IL-6 concentrations. Analysis of symptomatic (n = 101) and asymptomatic (n = 79) ICA stenosis did not detect a difference in levels of these markers.

CONCLUSIONS

Our study suggests that inflammatory markers could serve as markers for ICA atherosclerosis but are not useful to identify carotid plaque at risk for symptomatic conversion.

High-Sensitivity CRP Is Correlated With Neurologic Symptoms and Plaque Instability in Patients With Severe Stenosis of the Carotid Bifurcation

The aim of this study is to investigate the correlation of high-sensitivity C-reactive protein and E-selectin with clinical manifestations and plaque characteristics in 88 patients (69 with and 19 without neurological symptoms) with high-grade stenosis of the carotid bifurcation who underwent endarterectomy. The grade of stenosis was quantified by duplex ultrasonography and digital subtraction angiography. Preoperatively, serum high-sensitivity C-reactive protein and E-selectin were measured. Postoperatively, carotid plaque morphology was established according to the American Heart Association classification. High-sensitivity C-reactive protein levels were significantly ( P < .001) higher in symptomatic than in asymptomatic patients, as well as in patients with unstable compared with those with stable plaques ( P < .001). Serum high-sensitivity C-reactive protein levels correlated significantly ( P < .05) with macrophage count on the plaque. In conclusion, serum high-sensitivity C-reactive protein levels are associated with presence of neurological symptoms and plaque instability in patients with high-grade stenosis of the carotid bifurcation.

Conjugated linoleic acid supplementation reduces peripheral blood mononuclear cell interleukin-2 production in healthy middle-aged males

Conjugated linoleic acid (CLA) refers to geometric and positional isomers of linoleic acid. Animal studies have shown that CLA modulates the immune system and suggest that it may have a therapeutic role in inflammatory disorders. This double-blind placebo-controlled intervention trial investigated the effects of CLA supplementation on indices of immunity relating to cardiovascular disease (CVD) in a cohort of healthy middle-aged male volunteers. Subjects were randomly assigned to supplement their diet with 2.2 g 50:50 isomeric blend of cis 9, trans 11 (c9, t11)-CLA and trans 10, cis 12 (t10, c12)-CLA or placebo daily for 8 weeks. Interleukin (IL) 2, IL-10 and tumour necrosis factor (TNF) alpha were measured in the supernatant of cultured unstimulated and concanavalin A (Con A)-stimulated peripheral blood mononuclear cells (PBMC) by ELISA. Serum IL-6 and plasma CRP were measured by ELISA and plasma fibrinogen by automated clotting assay. Gene expression was investigated by real-time RT-PCR. CLA supplementation significantly reduced Con A-stimulated PBMC IL-2 secretion (37.1%; P=.02). CLA supplementation had no significant effect on transcription of IL-2. CLA supplementation had no direct significant effects on PBMC TNFalpha or IL-10 secretion. Other inflammatory markers associated with CVD, including IL-6, CRP and fibrinogen, were not affected by CLA supplementation. This study showed that CLA supplementation reduced PBMC IL-2 secretion from Con A-stimulated PBMC but lacked effect on other markers of the human inflammatory response.

Preprocedural C-reactive protein levels predict stroke and death in patients undergoing carotid stenting

BACKGROUND AND PURPOSE

Elevated baseline levels of C-reactive protein (CRP) are associated with an adverse outcome during coronary stent placement. The aim of this study was to evaluate whether preprocedural CRP levels also are predictive of stroke and death in patients undergoing carotid stent placement (CAS).

MATERIALS AND METHODS

We reviewed data prospectively collected from 130 patients (97 men, 33 women; mean age, 68.5 +/- 10.1 years; range, 43-89 years) who underwent CAS for symptomatic carotid stenosis and from whom preprocedural CRP values had been obtained. A CRP value of >5 mg/L was considered to be elevated. The frequency of stroke and death within 30 days was compared between patients with and without elevated baseline CRP levels using chi(2) and multivariate logistic regression analysis.

RESULTS

Baseline CRP values were normal in 94 (72.3%) patients but were elevated in 36 (27.7%) patients. The demographic and clinical characteristics were similar in both treatment groups. The 30-day stroke and death rate was significantly higher in patients with elevated CRP values (8/36; 22.2%) than in those without (3/94; 3.2%; P < .01). After adjusting for demographic characteristics, degree of carotid stenosis, and use of cerebral protection devices and/or statin therapy, an elevated CRP value before CAS remained a significant and independent predictor of stroke and death within 30 days after CAS (odds ratio, 7.7; 95% confidence interval: 1.8-32.8, P = .006).

CONCLUSIONS

Baseline CRP is a powerful predictor of outcome in patients undergoing CAS, which underscores the role of inflammation in the pathogenesis of embolic complications during this procedure.

Fibrinogen and high-sensitive C-reactive protein as serologic predictors for perioperative cerebral microembolic lesions after carotid endarterectomy

BACKGROUND

Neurologic deficit caused by cerebral ischemia defines the outcome of carotid endarterectomy (CEA). Although few patients have clinically evident neurologic deficit, diffusion-weighted imaging (DWI) presents a number of cases with ischemic brain lesions. This study should elucidate preoperative risk factors for perioperative microemboli that cause brain infarction.

METHODS

We studied 183 patients (58 women, 69.2 +/-12.7 years; 125 men, 69.3 +/- 8.9 years) with high-degree carotid artery stenosis. DWI was performed before and after CEA to analyze new cerebral ischemia. Blood samples were obtained before operation to measure fibrinogen and C-reactive protein (CRP), and preoperative high-sensitive CRP (hsCRP) was analyzed in 30 consecutive patients.

RESULTS

Postoperative DWI revealed new ipsilateral ischemic lesions in 41 patients (22.4%), and eight (4.4%) showed new neurologic deficit. Preoperative fibrinogen levels were higher in patients with new lesions (397.6 mg/dL +/- 104.7 mg/dL) than in those without (324.7 mg/dL +/- 74.2 mg/dL, P < .001). Preoperative levels of hsCRP were also higher in patients with new lesions (7.9 mg/dL +/- 5.2 mg/dL) than in those without (2.8 mg/dL +/- 2.6 mg/dL, P = .004). Significant association was found between fibrinogen and CRP (Spearman rho = 0.402; P < .001) as well as hsCRP (Spearman rho = 0.603, P = .003). No association was found between postoperative lesions and CRP (P = .833).

CONCLUSION

The present study demonstrates that preoperative levels of fibrinogen and hsCRP are independent determinants for new periprocedural cerebral ischemic lesions caused by microembolic events. There is still not sufficient evidence to recommend measurement of CRP as a prognostic marker for perioperative cerebral lesion.

C-Reactive Protein Level in Severe Stenosis of Cerebral Arteries

BACKGROUND

C-reactive protein (CRP) as a non-specific inflammatory biomarker has been demonstrated to actively contribute to all stages of atherogenesis. The aim of this study was to investigate the relation between CRP concentrations and the severity of stenosis of cerebral arteries.

METHODS

Lipid parameters and CRP levels were measured in the sera of 119 patients with stenosis of the extracranial cerebral arteries established by angiography and compared with the control group, with a normal appearance of the cerebral arteries on ultrasound examination. CRP concentrations were determined by a high-sensitivity assay.

RESULTS

CRP concentrations showed a statistically significant difference in the group of patients with cerebrovascular stenosis of more than 70% compared to the control group (median value 3.4 vs. 1.5 mg/l in the control group, p < 0.05). At logistic regression analysis, CRP was significantly associated with stenosis of more than 70%.

CONCLUSION

In addition to traditional biochemical risk markers, an elevated CRP level measured on automated analysers using a high-sensitivity assay may be useful in the detection of patients with severe stenosis of the cerebral arteries.

Prognostic role of C-reactive protein in very old patients with acute ischaemic stroke

BACKGROUND AND SCOPE

Recent literature has demonstrated that inflammation contributes to all phases of atherosclerosis and brain damage caused by stroke. In acute phase of cerebrovascular diseases biochemical markers of inflammation, such as C-reactive protein (CRP), could represent an indicator of severity of stroke, but few studies have verified this hypothesis, especially in very old patients. The aim of this study was to evaluate the role of CRP on short- and long-term prognosis in 75-year old and over elderly patients with acute ischaemic stroke.

MATERIALS AND METHODS

We retrospectively evaluated CRP values (nephelometric method), performed within 12 h from hospital admission, in 196 elderly patients (124 females and 72 males with mean age+/-SD 83.32+/-10.46 years), discharged with diagnosis of acute ischaemic stroke, 68 of them with atherothrombotic large vessel stroke, 38 with lacunar stroke and 90 with cardioembolic stroke. We studied the relationship between CRP values and short-term prognosis [30-day mortality, length of hospitalization (LOS) and physical disability measured by modified Rankin scale and long-term prognosis (12-month mortality and re-hospitalization)].

RESULTS

Mean values of CRP were significantly higher in patients with cardioembolic stroke compared with atherothrombotic large vessel and lacunar stroke, in patients who died in the first 30 days from the acute event compared with survivors. LOS and physical disability score rose with increasing values of CRP for all subtypes of stroke. Higher CRP values were associated with the 12-month re-hospitalization for cerebrovascular events, whereas it did not influence the 12-month cumulative re-hospitalization and 12-month mortality.

CONCLUSIONS

Elevation of CRP values at hospital admission could represent a negative prognostic index in elderly patients with ischaemic stroke, in particular, for short-term prognosis.

Evaluation of C-Reactive Protein Measurement for Assessing the Risk and Prognosis in Ischemic Stroke

Background and Purpose— Several studies have shown, in different populations, that modest elevation of plasma C-reactive protein (CRP) in the range seen in apparently healthy individuals is a strong predictor of future vascular events. Elevated plasma CRP concentrations are also associated with an increased risk of cerebrovascular events and an increased risk of fatal and nonfatal cardiovascular events in ischemic stroke patients. These epidemiological and clinical observations suggest that determination of plasma CRP concentrations could be used as an adjunct for risk assessment in primary and secondary prevention of cerebrovascular disease and be of prognostic value. The aim of this review is to summarize the evidence for CRP as an independent predictor of cerebrovascular events in at-risk individuals and ischemic stroke patients and to consider its usefulness in evaluating prognosis after stroke.

Summary of Review— CRP fulfils most of the requirements of a new risk and prognostic predictor, but several issues await further confirmation and clarification before this marker can be included in the routine evaluation of stroke patients and subjects at risk for cerebrovascular disease. Potentially important associations have been established between elevated plasma CRP concentrations and increased efficacy of established therapies, particularly lipid-lowering therapy with statins.

Conclusion— At present, there is not sufficient evidence to recommend measurement of CRP in the routine evaluation of cerebrovascular disease risk in primary prevention, because there is insufficient evidence as to whether early detection, or intervention based on detection, improves health outcomes, although shared risk of cardiovascular disease indicates this may be of value. In secondary prevention of stroke, elevated CRP adds to existing prognostic markers, but it remains to be established whether specific therapeutic options can be derived from this.

High-sensitivity C-reactive protein in high-grade carotid stenosis: risk marker for unstable carotid plaque

OBJECTIVES

Increasing evidence points to the inflammatory character of atherosclerosis, and several parameters of inflammation have been proposed as cardiovascular risk markers. We analyzed associations among serum high-sensitivity C-reactive protein (hs-CRP) concentrations, carotid plaque structure, and immunocytology, and neurologic symptoms in patients with high-grade carotid stenosis.

METHODS

This was a cross-sectional study in a referral center and institutional practice in hospitalized patients. The study included 62 patients with greater than 70% carotid stenosis treated surgically; 58% of patients had symptoms, and 42% did not. Serum hs-CRP concentrations were determined 48 hours before surgery; levels greater than 10 mg/L were considered pathologic. Histopathologic analysis (stable or unstable) and immunohistochemistry (macrophage count, T lymphocytes, activated T lymphocytes) were carried out on the atherosclerotic plaques.

RESULTS

Median hs-CRP values were 7.6 mg/L (range, 0-165 mg/L). Median hs-CRP concentrations were higher in patients with unstable plaque (53.2%) than in patients with stable plaque (46.7%): 27.1 mg/L (range, 1.8-165 mg/L) versus 4.1 mg/L (range, 0.3-56 mg/L) (P <.001). Among patients with symptomatic disease, 81% had CRP concentrations significantly higher than CRP concentrations in patients with asymptomatic disease (P <.001). A statistically significant association was found between hs-CRP levels and the presence of macrophages (Spearman rank correlation [rho], 0.61, P <.001) and T lymphocytes in the plaque (Spearman rank correlation [rho], 0.52, P <.001). At logistic regression analysis, neurologic event and macrophages in the plaque were independently associated with unstable plaque.

CONCLUSIONS

Increased hs-CRP levels may be related to the presence of macrophages and T lymphocytes in plaque, which is associated with the phenomena of instability that can lead to development of an ischemic event. Thus determination of circulating hs-CRP levels may be a useful additional marker of risk in patients with high-grade carotid stenosis.