A prospective evaluation of C-reactive protein in the progression of carotid artery stenosis

Inflammation in stroke: initial CRP levels can predict poor outcomes in endovascularly treated stroke patients

Background and purpose

Inflammation has been linked to poor prognoses in cardio- and cerebrovascular conditions. As it is known to increase after ischemia, C-reactive protein (CRP) may serve as a surrogate for systemic inflammation and thus be a hallmark of increased tissue vulnerability. The question arises whether CRP in the acute phase of ischemic stroke, prior to mechanical thrombectomy (MT), might help predict outcomes.

Materials and methods

A single-center collective of patients with large-vessel occlusion, who were treated via MT, was analyzed in this observational case-control study. Univariate and multivariate models were designed to test the prognostic value of inflammatory markers (CRP and leukocytosis) in predicting clinical outcomes (modified Rankin score >2) and all-cause mortality 90 days after MT.

Results

A total of 676 ischemic stroke patients treated with MT were included. Of these, 313 (46.3%) showed elevated CRP levels (≥5 mg/l) on admission. Poor clinical outcome and mortality at 90 days occurred in 113 (16.7%) and 335 (49.6%) patients and significantly more frequently when initial CRP levels were elevated [213 (64.5%) vs. 122 (42.1%), p < 0.0001, and 79 (25.2%) vs. 34 (9.4%), p < 0.0001, respectively]. CRP levels were highly predictive for impaired outcomes, especially in patients with atrial fibrillation, in both univariate and multivariate models. Interestingly, patients with initially elevated CRP levels also showed more pronounced increases in CRP post-MT.

Conclusion

Poor outcome and death occur significantly more often in stroke patients with elevated CRP levels before MT. Our findings suggest that stroke patients with atrial fibrillation and elevated inflammatory markers are of particular risk for poor outcomes.

The monomeric C-reactive protein level is associated with the increase in carotid plaque number in patients with subclinical carotid atherosclerosis

The high-sensitivity C-reactive protein (hsCRP) assay measures the level of the pentameric form of CRP in blood. Currently, there are no available assays measuring the level of the monomeric form of CRP (mCRP), produced at sites of local inflammation. We developed an assay measuring the mCRP level in blood plasma with functional beads for flow cytometry. The assay was used to measure the mCRP level in 80 middle-aged individuals with initially moderate cardiovascular SCORE risk. By the time of the mCRP measurement, the patients have been followed up for subclinical carotid atherosclerosis progression for 7 years. Ultrasound markers of subclinical atherosclerosis, which included plaque number (PN) and total plaque height (PH), were measured at baseline and at the 7th-year follow-up survey. Inflammatory biomarkers, including mCRP, hsCRP, inteleukin-6 (IL-6) and von Willebrand factor (VWF) level, were measured at the 7th-year follow-up survey. The median level of mCRP was 5.2 (3.3; 7.1) μg/L, hsCRP 1.05 (0.7; 2.1) mg/L, IL-6 0.0 (0.0; 2.8) pg/mL, VWF 106 (77; 151) IU/dL. In the patients with the mCRP level below median vs. the patients with the median mCRP level or higher, change from baseline in PN was 0.0 (0.0; 1.0) vs. 1.0 (1.0; 2.0) and PH 0.22 (−0.24; 1.91) mm vs. 1.97 (1.14; 3.14) mm, respectively (p < 0.05). The adjusted odds ratio for the formation of new carotid atherosclerotic plaques was 4.7 (95% CI 1.7; 13.2) for the patients with the median mCRP level or higher. The higher mCRP level is associated with the more pronounced increase in PN and PH in patients with normal level of traditional inflammatory biomarkers and initially moderate cardiovascular SCORE risk.

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.

A systemic review into carotid plaque features as predictors of restenosis after carotid endarterectomy

OBJECTIVE

Restenosis after carotid endarterectomy (CEA) limits its long-term efficacy for stroke prevention. Thus, it is of utmost importance to identify the factors that predispose a patient to restenosis after CEA. This systemic review aims to survey the current literature regarding restenosis after CEA and discuss the predictive value of carotid plaque features.

METHODS

A systemic review of studies on the predictive value of carotid plaque features for restenosis after CEA was conducted according to the PRISMA guidelines. PubMed/MEDLINE and Embase databases were searched up to March 20, 2020. Two authors independently extracted the data and assessed the risk of bias with the Quality in Prognosis Studies tool. Given the heterogeneity in the measurement of prognostic factors, types of CEA, and clinical outcomes, a qualitative synthesis was performed.

RESULTS

Twenty-one articles with a sample size that ranged from 11 to 1203 were included in this systematic review. Based on the presence of calcification in original carotid plaques, two progression patterns of restenosis were hypothesized: patients with calcified plaques may experience a temporary increase in the intima-media thickness (IMT) followed by a decrease in IMT after CEA, whereas patients with noncalcified plaques may experience a gradual increase in IMT after CEA. Accordingly, patients with a high calcium score may have a high restenosis rate within 6 months after CEA and a low restenosis rate thereafter. Thus, the late restenosis rate in patients with uniformly echogenic plaques was lower than that in patients with uniformly echolucent plaques. Pathologically, a lipid-rich, inflammatory carotid plaque is associated with a decreased risk of restenosis within 1 year after CEA, mainly owing to the relatively mild reactive intimal hyperplasia at the surgical site and active inflammation in the remaining media and adventitia. Molecular predictors for restenosis included a Mannose-binding lectin 2 genotype, preoperative C-reactive protein, serum homocysteine, apolipoprotein J, vitamin C, and telomere length of carotid plaques.

CONCLUSIONS

This review demonstrated that carotid plaque features, including imaging features, cellular composition, and molecular features, are correlated with the risk of restenosis after CEA. A comprehensive evaluation of plaque characteristics may help to stratify the risk of restenosis after CEA.

Elevated Hs-CRP Levels Are Associated with Higher Risk of Intracranial Arterial Stenosis

Correlation between the level of high-sensitivity C-reactive protein (hs-CRP) and the incidence of intracranial arterial stenosis (ICAS) is unclear. We aim to investigate the relationship between hs-CRP levels and ICAS. A total of 1458 patients aged ≥ 40 years were enrolled in this study. All the participants had a magnetic resonance angiography (MRA) examination for the evaluation of ICAS. Participants were classified into four groups according to stroke and ICAS. Multivariable logistic regression models were used to assess the relationship of hs-CRP levels and ICAS status. A total of 432 (29.63%) subjects had ICAS. The levels of hs-CRP in stroke group were significantly higher than those in non-stroke group (p < 0.001). Patients with ICAS tend to have higher hs-CRP levels (p < 0.001). In multivariate analysis, the fourth hs-CRP quartile had the strongest association with ICAS in both stroke group and non-stroke group (OR 2.512, 95% CI 1.651-3.853, p < 0.001 for stroke group, and OR 2.534, 95% CI 1.435-4.595, p = 0.002 for non-stroke group) among the four quartiles of hs-CRP levels. Our study suggests that elevated serum hs-CRP levels are associated with higher risk of ICAS, in both stroke patients and non-stroke participants.

ECAS progression score: a web-based model to predict progression of extracranial carotid artery stenosis

BACKGROUND AND PURPOSE

To develop and validate a risk model (Extracranial Carotid Artery Stenosis progression score, ECAS-PS) and to predict risk of ECAS progression.

METHODS

The ECAS-PS was developed based on the Renqiu Stroke Screening Study (RSSS), in which eligible participants were randomly divided into derivation (60%) and validation (40%) cohorts. ECAS at baseline and follow-up was diagosed by carotid duplex ultrasound according to the published criteria. ECAS progression was defined as an increase in ECAS to≥50% for those with a baseline of <50% or as an increase to a higher category of stenosis if the baseline stenosis was ≥50%. Independent predictors of ECAS progression were obtained using multivariable logistic regression. The area under the receiver operating characteristic curve (AUROC) and the Hosmer-Lemeshow test were used to assess model discrimination and calibration.

RESULTS

A total of 4111 participants were included and the mean age was 64.3. A total number of 29 (0.7%), 24 (0.6%) and 48 (1.2%) patients progressed during 2-year follow-up for left, right and bilateral (either left or right) carotid artery, respectively. The ECAS-PS was developed from a set of predictors of ECAS progression. The ECAS-PS demonstrated good discrimination in both the derivation and validation cohorts (AUROC range: 0.824-0.917). The Hosmer-Lemeshow tests of ECAS progression score were not significant in the derivation and validation cohorts (all P > 0.05).

CONCLUSION

The ECAS progression score is a valid model for predicting the risk of ECAS progression. Further validation of the ECAS-PS in different populations and larger samples is warranted.

ECAS score: a web-based risk model to predict moderate and severe extracranial carotid artery stenosis

Background and purpose To develop and validate a risk model (Extracranial Carotid Artery Stenosis score, ECAS score) to predict moderate and severe ECAS. Furthermore, we compared discrimination of the ECAS score and three existing models with regard to both moderate and severe ECAS. Methods The ECAS score was developed based on the Renqiu Stroke Screening Study (RSSS), in which eligible patients were randomly divided into derivation (60%) and validation (40%) cohorts. ECAS was diagnosed by carotid duplex ultrasound according to the published criteria. Independent predictors of moderate (≥50%) and severe (≥70%) ECAS were obtained using multivariable logistic regression. The area under the receiver operating characteristic curve (AUROC) and the Hosmer-Lemeshow test were used to assess model discrimination and calibration. Results A total of 5010 participants were included and the mean age was 64.3. The proportion of ECAS of < 50%, 50-69%, 70-99% and occlusion was 4.4, 0.5, 0.4, and 0.4%, respectively. The ECAS score was developed from sets of predictors of moderate and severe ECAS. The ECAS score demonstrated good discrimination in the derivation and validation cohorts (AUROC range: 0.785-0.846). The Hosmer-Lemeshow tests of ECAS score for moderate and severe ECAS were not significant in the derivation and validation cohorts (all P > 0.05). When compared to the three existing models, the ECAS score showed significantly better discrimination for both moderate and severe ECAS (all P < 0.001). Conclusion The ECAS score is a valid model for predicting moderate and severe ECAS. Further validation of the ECAS score in different populations and larger samples is warranted.

C-reactive protein in atherosclerosis - A risk marker but not a causal factor? A 13-year population-based longitudinal study: The Tromsø study

BACKGROUND AND AIMS

CRP predicts cardiovascular disease (CVD) in large epidemiologic studies. The aim of the present study was to elucidate the role of CRP in atherosclerosis formation and progression in a prospective population-based study.

METHODS

6503 middle-aged subjects from The Tromsø study had serum CRP, carotid ultrasound and complete covariate data collected at baseline in 1994. Of these, 4730 and 2917 attended follow-up surveys with repeated assessments in 2001 and 2007, respectively. The cross-sectional associations between CRP and subclinical carotid atherosclerosis, and the longitudinal associations between baseline CRP and novel plaque formation and plaque progression were assessed in generalized estimating equations and linear mixed models stratified by sex.

RESULTS

At baseline, traditional risk factors and plaque prevalence increased by CRP risk categories (<1 mg/L, 1-3 mg/L, and >3 mg/L) in both sexes. In cross-sectional analyses, multivariable-adjusted CRP was associated with plaque prevalence and total plaque area (TPA) in men and women. Age-adjusted baseline CRP >3 mg/L compared to CRP <1 mg/L predicted novel plaque formation (OR 1.44, CI 1.08-1.92) and TPA progression (β = 0.0.029 (CI, 0.003-0.056)) in men, but not in women. In neither men nor women was baseline CRP a predictor of TPA-progression or novel plaque formation when adjusted for traditional risk factors.

CONCLUSIONS

CRP was associated with plaque presence and TPA in cross-sectional analyses, but was not an independent predictor of novel plaque formation or plaque progression. Our findings suggest that CRP may link to CVD by other mechanisms than promoting formation and progression of atherosclerotic plaques.

The Impact of Biochemical Markers on Major Adverse Cardiovascular Events and Contralateral Carotid Artery Stenosis Progression Following Carotid Interventions

BACKGROUD

To determine if elevated preintervention high-sensitivity C-reactive protein (hsCRP) and B-type natriuretic peptide (BNP) levels associate with major adverse cardiovascular events (MACE) or disease progression after carotid revascularization.

METHODS

We retrospectively examined patients receiving elective carotid endarterectomy (CEA) or carotid artery stenting (CAS) at our institution from 2007 to 2014. All included patients had preintervention hsCRP and BNP levels. Examined outcomes of interest included contralateral carotid disease progression (increased stenosis or need for revascularization) and MACE (composite of death, stroke, myocardial infarction, need for coronary artery bypass graft or percutaneous coronary intervention) at 3 years after procedure. The relationship between baseline hsCRP and BNP levels and time to event was examined by univariate and multivariate Cox proportional hazard regression analyses.

RESULTS

A total of 248 patients were included in the analysis (mean age: 68 ± 10 years), with 14% receiving CAS and 86% CEA. A total of 61 patients (25%) had 1 or more MACE by 3 years. Elevated hsCRP (>3 mg/L) trended toward associating with MACE but failed to reach significance (hazard ratio [HR]: 1.6 [1.0-2.7], P = 0.07). Multivariate analysis found that elevated BNP (>100pg/mL, HR: 2.2 [1.3-3.7], P = 0.002) and diabetes mellitus (HR: 1.9 [1.2-3.2], P = 0.01) predicted MACE. Having elevated preprocedural levels of both hsCRP and BNP significantly increased patients' likelihood of experiencing MACE (HR: 3.4 [1.6-7.1], P = 0.001). About 175 patients received contralateral carotid imaging postprocedure and of those patients, 31 (18%) experienced stenosis progression and/or revascularization within 3 years. However, neither elevated hsCRP (HR: 1.2 [0.6-2.3], P = 0.68) nor BNP (HR: 1.1 [0.5-2.5], P = 0.88) associated with disease progression.

CONCLUSIONS

BNP elevation at the time of carotid intervention is associated with MACE in long-term follow-up. hsCRP does not appear to correlate with either disease progression of the contralateral artery or MACE.

Higher Levels of Cystatin C Are Associated with Extracranial Carotid Artery Steno-Occlusive Disease in Patients with Noncardioembolic Ischemic Stroke

Background

Large artery atherosclerosis is a major cause of ischemic stroke worldwide. Differential biomarker profiles associated with extra- and intracranial atherosclerosis are a topic of considerable interest. Cystatin C (CysC), a marker of renal function, is a risk factor for cardiovascular disease.

Aim

We sought to determine whether CysC levels were associated with extra- and intracranial large artery stenosis (LAS) in patients with acute ischemic stroke.

Methods

We retrospectively analyzed data of acute noncardioembolic ischemic stroke patients who were admitted to our stroke center within 5 days from symptom onset. Serum CysC levels were measured using latex agglutination turbidimetric immunoassay. Extra- and intracranial LAS were defined as ≥50% diameter stenosis or occlusion of the relevant internal carotid artery (ICA) and/or middle cerebral artery (MCA) using carotid echography and volume rendering on magnetic resonance angiography. Multivariate logistic analyses were used to assess the association between CysC levels and LAS after adjustment for potential confounders.

Results

Of 205 patients (mean age 70.2 years), 76 (37.1%) had LAS. The distribution of LAS was 29 extracranial ICA, 34 intracranial ICA/MCA (8 ICA only, 25 MCA only, 1 ICA+MCA) and 13 tandem stenosis (both extracranial ICA and intracranial ICA/MCA). Levels of CysC were higher in patients with extracranial ICA stenosis than in those with intracranial ICA/MCA stenosis (1.23 ± 0.33 vs. 0.97 ± 0.21 mg/l, p < 0.001). In multivariate analysis, the highest CysC tertile (>1.04 mg/l) was significantly associated with extracranial ICA stenosis (adjusted odds ratio [OR] 5.01, 95% confidence interval [CI] 1.51-16.63, p = 0.009) after adjustment for age, sex, diabetes, chronic kidney disease, current smoking, systolic blood pressure, HDL cholesterol, high-sensitivity C-reactive protein (hs-CRP) and premorbid lipid-lowering drugs use. When CysC was considered as a continuous variable, 1 SD increase in CysC was significantly associated with extracranial ICA stenosis (adjusted OR 3.01, 95% CI 1.58-5.72, p = 0.001). However, there were no significant associations between CysC levels and intracranial ICA/MCA stenosis. In addition, CysC levels showed a weak but statistically significant correlation with hs-CRP levels (r = 0.195, p = 0.021). Using receiver operating characteristic curve analysis, CysC value displayed good performance in discriminating extracranial ICA stenosis (c-statistic 0.79, 95% CI 0.69-0.89, p < 0.001).

Conclusions

This preliminary study suggests that higher levels of CysC were independently associated with symptomatic extracranial ICA stenosis, but not with intracranial ICA/MCA stenosis in patients with noncardioembolic stroke. Our findings provide new insights into the link between serum CysC and carotid atherosclerosis.

Definition of Best Medical Treatment in Asymptomatic and Symptomatic Carotid Artery Stenosis

Implementation of best medical treatment (BMT) is the cornerstone of the management of patients with either asymptomatic or symptomatic carotid artery stenosis. We review the literature to define the components of BMT. Smoking cessation, maintaining a healthy body weight, moderate exercise, and a Mediterranean diet are essential lifestyle measures. Moderate alcohol consumption may also be beneficial but recommending it to patients may be hazardous if they consume too much. The importance of lifestyle measures is largely underestimated by both physicians and patients. Blood pressure and diabetes control, antiplatelet agents, and lipid-lowering treatment with statins/ezetimibe comprise the pharmacological components of BMT. Initiation of an intensive regimen of BMT is a sine qua non for patients with carotid artery stenosis whether or not they are offered or undergo an invasive revascularization procedure.

Association between high sensitivity C-Reactive protein and prevalence of asymptomatic carotid artery stenosis

INTRODUCTION

Inflammation plays a key role in the pathophysiology of atherosclerosis. Little is known about the association between high sensitivity C-reactive protein (hs-CRP) especially long-term hs-CRP and asymptomatic carotid artery stenosis (ACAS) in healthy Chinese adults. The aim of this study was to assess the relationship between hs-CRP levels and the prevalence of ACAS in a Chinese community-based cohort.

METHODS

A sample of 5349 participants aged ≥ 40 years (40.36% women) were enrolled in this study, all without preexisting stroke. Ultrasonography of the bilateral carotid arteries was performed for the evaluation of carotid stenosis. Participants were stratified into three groups according to hs-CRP levels. We used both baseline (hs-CRP levels analyzed during 2010) and average hs-CRP values for the last four years (the average of hs-CRP levels analyzed at the year of 2006, 2008 and 2010) in the analysis. Multivariable logistic regression models were used to analyze the association between hs-CRP levels and ACAS.

RESULTS

A total of 356 (6.66%) subjects showed evidence of ACAS. Multivariate analysis showed that both baseline and average hs-CRP values for the last four years were independent indicators for the presence of ACAS (P for trend = 0.007, 0.001, respectively). Stratified by age and sex, higher baseline hs-CRP levels were associated with ACAS in old adults (≥ 60 y) (multivariate-adjusted, odds ratio [OR] = 1.03, 95% confidence interval [CI]: 1.01-1.05) and male (multivariate-adjusted, OR = 1.03, 95%CI: 1.01-1.05), but not in middle-aged adults (40-59 y) and female. Similarly, higher average hs-CRP values for the last four years were associated with ACAS in old adults and male, but not in middle-aged adults and female.

CONCLUSION

Both baseline and chronic elevation of serum hs-CRP were associated with ACAS, especially in older or male adults. hs-CRP might be used as a useful marker and a potential therapeutic target for carotid atherosclerosis.

Association of Serum Pentraxin-3 and High-Sensitivity C-Reactive Protein with the Extent of Coronary Stenosis in Patients Undergoing Coronary Angiography

Background

We compared factors of inflammation – high sensitivity C-reactive protein (hsCRP) and pentraxin-3 (PTX3), and we explored their relationship with coronary artery disease (CAD). Also, we tested the usefulness of hsCRP and PTX3 in the risk assessment of coronary stenosis development and the diagnostic ability of these biomarkers to detect disease severity.

Methods

The study group consisted of 93 CAD patients undergoing coronary angiography. Patients were divided into CAD(0), representing subclinical stenosis, and CAD (1–3), representing significant stenosis in one, two or three vessels.

Results

We determined the concentration of lipid status parameters, hsCRP and PTX3. We found significantly lower PTX3 and hsCRP concentrations in CAD(0) than in CAD(1–3) group. Concentration of PTX3 showed an increasing trend with the increasing number of vessels affected. The area under ROC curve (AUC) for the combinations of hsCRP and PTX3 with lipid parameters had useful accuracy for detecting CAD(1–3) patients (AUC=0.770, p<0.001).

Conclusion

PTX3 is a promising independent diagnostic marker for identifying patients with CAD, and a useful indicator of disease progression. In all the analyses PTX3 showed better performance than hsCRP. A combination of PTX3, hsCRP with the lipid status parameters provides risk stratification of the development of coronary stenosis and better classification than their individual application.

The relationships between serum C-reactive protein level and risk and progression of coronary and carotid atherosclerosis

The acute-phase protein, C-reactive protein (CRP), was discovered >80 years ago and has been used clinically as a biomarker of inflammation. The measurement of serum CRP levels has proven useful to determine disease progression and the effectiveness of treatments for a number of medical conditions (eg, cancer, infection, and inflammation). During the last 20 years, multiple studies have shown an increased CRP level to be an indicator of risk for coronary artery disease and to be associated with progression of atherosclerotic carotid occlusive disease. In this review, the most recent associations of CRP with cardiovascular disease in both coronary and carotid artery circulations are analyzed. It is imperative that the vascular surgeon and other vascular specialists recognize the relationship between serum CRP levels and atherosclerotic disease to identify at-risk patient populations, screen for occlusive disease severity, and employ this biomarker in patient counseling.

Management of extracranial carotid artery disease

Stroke is the third leading cause of death in developed nations. Up to 88% of strokes are ischemic in nature. Extracranial carotid artery atherosclerotic disease is the third leading cause of ischemic stroke in the general population and the second most common nontraumatic cause among adults younger than 45 years. This article provides comprehensive, evidence-based recommendations for the management of extracranial atherosclerotic disease, including imaging for screening and diagnosis, medical management, and interventional management.

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.

Progression of experimental lesions of atherosclerosis: assessment by kinetic modeling of black-blood dynamic contrast-enhanced MRI

Pharmacokinetic modeling of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) is used to noninvasively characterize neovasculature and inflammation in atherosclerotic vessels by estimating perfusion characteristics, such as fractional plasma volume vp and transfer constant Ktrans. DCE-MRI has potential to study the evolution of nascent lesions involving early pathological changes. However, currently used bright-blood DCE-MRI approaches are difficult to apply to small lesions because of the difficulty in separating the signal in the thin vessel wall from the adjacent lumen. By suppressing the lumen signal, black-blood DCE-MRI techniques potentially provide a better tool for early atherosclerotic lesion assessment. However, whether black-blood DCE-MRI can detect temporal changes in physiological kinetic parameters has not been investigated for atherosclerosis. This study of balloon-injured New Zealand White rabbits used a reference-region-based pharmacokinetic model of black-blood DCE-MRI to evaluate temporal changes in early experimental atherosclerotic lesions of the abdominal aorta. Six rabbits were imaged at 3 and 6 months after injury. Ktrans was found to increase from 0.10±0.03 min(-1) to 0.14±0.05 min(-1) (P=0.01). In histological analysis of all twelve rabbits, Ktrans showed a significant correlation with macrophage content (R=0.70, P=0.01). These results suggest black-blood DCE-MRI and a reference-region kinetic model could be used to study plaque development and therapeutic response in vivo.

High sensitivity C-reactive protein predicts the development of new carotid artery plaques in older persons

BACKGROUND AND AIM

Previous studies have shown that increased levels of C-reactive protein (CRP) predict cardiovascular events, including stroke, myocardial infarction and death from cardiovascular causes. Previous studies have also shown that increased levels of CRP are strong predictors of the progression of pre-existing carotid artery plaques. However, whether CRP is involved in the development of new plaques, that may or may not be associated with clinical events, in subjects with clean carotid arteries has been scarcely investigated.

METHODS AND RESULTS

486 "InCHIANTI" Study participants (200 men and 286 women, 72% aged 65 years and over) free from carotid artery plaques at baseline, also underwent carotid artery scan three years later. We tested the association of baseline characteristics, cardiovascular risk factors and inflammatory markers with the development of new carotid artery plaques. Older participants were significantly more likely to develop new plaques. Independent of age, the relative risks of developing new plaques associated with heavy smoking and family history of atherosclerosis were 1.7 (95%CI 1.5-1.9) and 1.9 (95%CI 1.2-3.1), respectively. Participants with high (>3 μg/mL) and moderate (≥1 and ≤3 μg/mL) CRP levels had a relative risk of 2.2 (95%CI 1.9-2.6) and 1.9 (95%CI 1.6-2.3) respectively, when compared with subjects with low (<1 μg/mL) CRP levels. Surprisingly, risk factors such as hypertension, diabetes, dyslipidemia and overweight/obesity were not significant predictors of the development of new carotid artery plaques.

CONCLUSIONS

High CRP levels independently predict the development of new plaques in older persons with carotid arteries free from atherosclerotic lesions.

Novel uses for statins in surgical patients

BACKGROUND

Aside from their cholesterol-lowering effects statins are known to have a range of other 'pleiotropic' effects. We present an overview of the basic science behind these effects and then review clinical trials and the current role of statins relevant to modern surgical practice.

METHODS

A systematic review of the literature was performed using the keywords surgery and the MeSH term for statins. All clinical studies relating to statin use in surgical patients were evaluated. An overview of the literature on statin use and cardiac outcomes was performed.

CONCLUSIONS

Statins are safe and have a wide range of pleiotropic effects relevant to surgical practice. Strongest evidence for their clinical use comes in primary cardiac risk reduction in many types of vascular surgery. There is a large body of evidence showing their benefit perioperatively in high-risk vascular and cardiac surgery but the picture is less clear for low-risk patients. Further studies are needed to evaluate exact dosage regimes and timing of administration. Novel uses of their anti-inflammatory properties in sepsis and vasomotor properties in subarachnoid haemorrhage are being further investigated by randomised trials.