Transcardiac gradient of soluble adhesion molecules predicts progression of coronary artery disease

Trans-Myocardial Blood Interleukin-6 Levels Relate to Intracoronary Imaging-Defined Features of Plaque Vulnerability and Predict Procedure-Induced Myocardial Infarction

BACKGROUND

Intravascular imaging has defined various vulnerable plaque (VP) phenotypes that predict future clinical events. Atherosclerosis is an inflammatory process and inflammation, measured by systemic biomarkers can also predict events and anti-inflammatory therapy is beneficial. We were interested to assess the relationship between plaque phenotypes and key inflammatory biomarkers, measured close to the coronary.

METHODS

Ninety-two patients scheduled for elective percutaneous coronary intervention (PCI) underwent virtual histology intravascular ultrasound, optical coherence tomography, pressure wire and blood sampling from the guide catheter (GC), coronary sinus (CS) to determine trans-myocardial gradient (TMG = CS-GC) and from peripheral blood. Procedure related troponin release was assessed at 6-hours post-PCI from peripheral venous blood. Biomarker data were analysed and compared with coronary data.

RESULTS

Interleukin (IL)-6 was associated with increased levels of tumour necrosis factor (TNF)-α and C-reactive protein (CRP) and the pre-PCI IL-6 TMG correlated with plaque features of vulnerability: plaque burden - PB (r = 0.253, p = 0.04) and minimal lumen area - MLA (r = -0.438, p = 0.007), although no relationship existed for thin-capped fibroatheroma defined by either imaging modality. Peripheral IL-6 levels had no correlation with post PCI troponin, although the pre-PCI IL-6 TMG was related (r = 0.334, p = 0.006), as was PB (r = 0.27, p = 0.029).

CONCLUSION

IL-6 TMG pre-PCI correlates with plaque burden and MLA that have been shown to predict future clinical events and is correlated with post-PCI troponin release. These associations were not apparent from peripheral blood and suggest that local coronary biomarker signatures may help further define vulnerability and risk.

Down-regulation of CREB-binding protein expression blocks thrombin-mediated endothelial activation by inhibiting acetylation of NF-κB

OBJECTIVES

CREB-binding protein (CBP) belongs to a unique class of transcription co-activators possessing histone acetyltransferase (HAT) activity. The aim of the present study was to evaluate the role of CBP in thrombin-induced endothelial activation, and also explore the underlying mechanism.

METHODS

Leukocyte-endothelial adhesion was calculated as the proportion of the labeled-neutrophils that adhered to ECs relative to all neutrophils applied. Levels of adhesion molecules were analyzed by real-time RT-PCR and western blot. Electrophoretic mobility shift assay and NF-κB reporter assay were performed to evaluate NF-κB activation. Acetylation of NF-κB was measured with immunoprecipitation and western blot assay. To detect the CBP-HAT activity, acetyl residues on an acetylated histone H4 was analyzed.

RESULTS

Leukocyte-endothelial adhesion induced by thrombin was markedly attenuated in endothelial cells with CBP knockdown. The decreased adhesion was paralleled by the reduction of vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and E-selectin. Furthermore, CBP silencing suppressed thrombin-mediated NF-κB activation, and this inhibitory effect was associated with decreased acetylation of NF-κB and CBP-HAT activity.

CONCLUSIONS

Our results indicate that CBP is involved in the regulation of endothelial activation via NF-κB-dependent pathway. Down-regulation of CBP may play a role in returning ECs from a pre-inflammatory status to a quiescent state in the pathogenesis of atherosclerosis.

Carotid intima-media thickness and markers of inflammation, endothelial damage and hemostasis

BACKGROUND

Different soluble molecules involved in inflammation, endothelial damage, or hemostasis are recognized as potential cardiovascular risk markers. Studies to assess the role of these markers in the atherosclerotic process by evaluating their relationship to carotid intima-media thickness (C-IMT) tend to provide contrasting results.

PURPOSE

To perform a review of studies addressing the association between C-IMT and soluble markers and to investigate whether the observed inconsistencies could be explained by the characteristics of the patients included in different studies, for example prevalence of atherosclerotic disease (atherosclerotic burden), gender, age, or occurrence of specific vascular risk factors (VRFs).

DATA SOURCES

PubMed and Embase (January 1990 to March 2006).

STUDY SELECTION

Articles in English reporting original cross-sectional studies.

DATA EXTRACTION

Two authors independently extracted data on study design, population, sample size, ultrasonic methodology, and statistical approach.

DATA SYNTHESIS

Despite the marked heterogeneity of results presented in the literature, meta-analysis established that studies showing positive associations between C-IMT and plasma levels of C-reactive protein (CRP) or fibrinogen are in the majority. Funnel plot analyses suggested the absence of an important publication bias. Data on the relationships between C-IMT and other soluble markers are by contrast scanty, contradictory, or unconfirmed by multivariate (as opposed to univariate) analyses, and the freedom from publication bias here cannot be vouched for. The degree of atherosclerotic burden in the population studied does not account for the heterogeneity of findings reported. Gender, noninsulin-dependent diabetes mellitus (NIDDM) and hypercholesterolemia influence the association between C-IMT and CRP. Blood pressure and hypercholesterolemia influence the association between C-IMT and fibrinogen. For all the other soluble markers considered, the number of groups was too small for this kind of statistical considerations.

LIMITATIONS

Heterogeneity in ultrasound methodologies and in statistical approach limited comparability between studies. For most soluble markers, publication bias of positive results cannot be excluded.

CONCLUSIONS

Only CRP and fibrinogen seem to be unequivocally related to C-IMT. For all the other soluble markers considered, no clear-cut conclusions can be drawn.

The selective estrogen receptor-beta agonist biochanin A shows vasculoprotective effects without uterotrophic activity

OBJECTIVE

Current hormone therapy in postmenopausal women is associated with uterotrophic activity and cancer-promoting effects. In this experimental study, we compared the effects of the selective estrogen-receptor (ER) beta agonist biochanin A, and the selective ERalpha agonist ethinylestradiol, on the development of intimal hyperplasia after balloon injury and on uterus morphology.

DESIGN

Female F344 rats with or without prior ovariectomy were used for aortic denudations. Animals remained untreated or received oral biochanin A (100 mg/kg) or ethinylestradiol (100 microg/kg). After 14 days, aortas and uteri were harvested for histologic and immunohistochemical analyses. Computerized assessments of aortic adhesion molecule expression, and isometric relaxation experiments, and uteri were analyzed. In vitro studies with smooth muscle cells and endothelial cells were performed to further investigate the effects of hormone treatment on cell proliferation, migration and adhesion molecule expression.

RESULTS

Among untreated rats, ovariectomized animals tended to show greater neointimal hyperplasia and increased expression of the adhesion molecules 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1). Biochanin A treatment reduced neointima formation, inhibited VCAM-1 up-regulation, and improved the vascular relaxation response. No effect was observed on uterus growth or histology. Ethinylestradiol also reduced aortic neointima formation and inhibited VCAM-1 up-regulation, but failed to improve endothelial function and significantly induced uterus growth. Both agents showed antiproliferative and weak antimigratory effects on smooth muscle cells, and reduced VCAM-1 expression on stimulated endothelial cells in vitro.

CONCLUSIONS

The ERbeta agonist biochanin A shows vasculoprotective effects without uterotrophic activity. Because hormone therapy may have cancer-promoting side effects, administration of ERbeta-selective agents might be alternatively used to reduce the risk of cardiovascular disease in postmenopausal women.

Markers of endothelial dysfunction in the prediction of coronary artery disease in type 1 diabetes. The Pittsburgh Epidemiology of Diabetes Complications Study

Low-density lipoprotein (LDL) oxidation, the immune response it provokes, and lipoprotein subclasses measured by nuclear magnetic resonance (NMR) spectroscopy have explained some of the enhanced coronary artery disease (CAD) risks in Type 1 diabetes. We examined whether cellular adhesion molecules further improve CAD prediction. Participants were identified from the Epidemiology of Diabetes Complications (EDC) cohort, a 10-year prospective study of childhood-onset Type 1 diabetes. Mean age at baseline was 28 years, and diabetes duration was 19 years. CAD incidence was determined by EDC physician-diagnosed angina, confirmed myocardial infarction (MI), stenosis > or =50%, ischemic ECG, or revascularization. Cases were gender, age, and diabetes duration (+/-3 years) matched with the controls. The samples and risk factors used in the analyses were identified from the earliest exam prior to incidence in the cases. Sixty cases and 72 controls (including 43 pairs) had complete information on all covariates. Cox proportional hazard models with backward elimination and conditional logistic regression (for paired analyses) were conducted. Separate analyses were conducted to examine whether E-selectin related differently to soft (ischemic ECG and angina; n=68) or hard (revascularization, MI, and fatal events; n=37) CAD endpoints. Mean E-selectin concentration was elevated among cases (P=.0009) compared to controls. Adjusting for previously established CAD risk factors, E-selectin remained an independent predictor of CAD (HR=1.07, 95% Cl=1.01-1.15). Multivariable models confirmed the importance of E-selectin as a risk factor of soft (HR=1.13, 95% Cl=1.03-1.24; HRs are per standard deviation increase) but not hard CAD. Study results suggest that E-selectin may enhance CAD prediction beyond traditional risk factors or markers of oxidative stress in Type 1 diabetes.

Levels of soluble adhesion molecules in various clinical presentations of coronary atherosclerosis

Adhesion molecules play an important role in the development and course of coronary atherosclerosis. In this study, soluble forms of vascular cell adhesion molecule (VCAM-1) intercellular adhesion molecule-1 (ICAM-1), E-selectin and P-selectin were evaluated in patients with various clinical presentations of coronary atherosclerosis and compared them to those with angiographically documented normal coronary arteries. Venous plasma samples were collected from 43 patients with acute myocardial infarction (AMI), 45 with unstable angina pectoris (UAP), 34 with stable angina pectoris (SAP) and 29 subjects with normal coronary arteries (control). The VCAM-1 level was significantly higher in patients with AMI (mean +/- SEM; 799.8 +/- 26.3 ng/ml) than those with UAP (644.2 +/- 26.7 ng/ml) and SAP (526 +/- 32.5 ng/ml) and controls (270 +/- 26.8 ng/ml). In patients with UAP, VCAM-1 was found to be significantly elevated as compared to the SAP group and controls. VCAM-1 level was also higher in SAP group than the controls. Serum levels ICAM-1 were similar among patients with AMI (424.1 +/- 15.2 ng/ml), UAP (403 +/- 12.3 ng/ml) and SAP (381.2 +/- 16.2 ng/ml); however, levels of ICAM-1 was significantly elevated in these groups as compared to the controls (244.3 +/- 11). The mean level of E-selectin was not different in AMI and UAP groups (47.2 +/- 2.2 vs. 42.6 +/- 2.1 ng/ml; respectively). However, it was significantly higher in acute coronary syndrome groups as compared to SAP (33.4 +/- 2.3 ng/ml) and control subjects (30.7 +/- 1.9 ng/ml). Serum levels of E-selectin were similar in SAP group and controls. For P-selectin, no significant difference was observed between AMI and UAP groups (187.5 +/- 7.2 vs. 181.7 +/- 4.7 ng/ml; respectively), however, it was significantly higher in both groups as compared to SAP group (146.1 +/- 7.4 ng/ml) and controls (108 +/- 6.6 ng/ml). Serum level of P-selectin was significantly higher in patients with SAP than the control group. In conclusion, determination of serum VCAM-1, E-selectin and P-selectin levels seems more useful for detecting coronary plaque destabilization.

Recent advances in vascular inflammation: C-reactive protein and other inflammatory biomarkers

PURPOSE OF REVIEW

Inflammatory vascular diseases are initiated and perpetuated by the interaction of immune cells with cells of the affected vessel wall. This is directed by a network of chemical messengers, which, in a state of vascular health, exist as balanced but opposing forces. Our understanding of this highly complex process has advanced significantly in the last several decades. The detection of vascular inflammation and monitoring of this activity have long been attempted in systemic vasculitis, and, more recently, in atherosclerosis. Markers of vascular inflammation used thus far have been of limited value; few provide both adequate sensitivity and specificity for any particular disease. New insights into the pathophysiology of vascular inflammation have identified other potential markers that may improve detection and monitoring of these conditions.

RECENT FINDINGS

Immunomodulatory mediators of the inflammatory cascade have been identified, and their roles are being defined. There are recent data that implicate various cytokines, proteases, adhesion molecules, and acute phase proteins as participants in the generation of vascular inflammation.

CONCLUSION

The pursuit of highly sensitive and specific markers of vascular inflammation has produced a wealth of information that has been instrumental in advancing our comprehension of this complex process. Further studies will establish the role of these new markers in the diagnosis, monitoring, and prognostication of inflammatory vascular disease.

From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies: Part I

Atherosclerotic cardiovascular disease results in >19 million deaths annually, and coronary heart disease accounts for the majority of this toll. Despite major advances in treatment of coronary heart disease patients, a large number of victims of the disease who are apparently healthy die suddenly without prior symptoms. Available screening and diagnostic methods are insufficient to identify the victims before the event occurs. The recognition of the role of the vulnerable plaque has opened new avenues of opportunity in the field of cardiovascular medicine. This consensus document concludes the following. (1) Rupture-prone plaques are not the only vulnerable plaques. All types of atherosclerotic plaques with high likelihood of thrombotic complications and rapid progression should be considered as vulnerable plaques. We propose a classification for clinical as well as pathological evaluation of vulnerable plaques. (2) Vulnerable plaques are not the only culprit factors for the development of acute coronary syndromes, myocardial infarction, and sudden cardiac death. Vulnerable blood (prone to thrombosis) and vulnerable myocardium (prone to fatal arrhythmia) play an important role in the outcome. Therefore, the term "vulnerable patient" may be more appropriate and is proposed now for the identification of subjects with high likelihood of developing cardiac events in the near future. (3) A quantitative method for cumulative risk assessment of vulnerable patients needs to be developed that may include variables based on plaque, blood, and myocardial vulnerability. In Part I of this consensus document, we cover the new definition of vulnerable plaque and its relationship with vulnerable patients. Part II of this consensus document focuses on vulnerable blood and vulnerable myocardium and provide an outline of overall risk assessment of vulnerable patients. Parts I and II are meant to provide a general consensus and overviews the new field of vulnerable patient. Recently developed assays (eg, C-reactive protein), imaging techniques (eg, CT and MRI), noninvasive electrophysiological tests (for vulnerable myocardium), and emerging catheters (to localize and characterize vulnerable plaque) in combination with future genomic and proteomic techniques will guide us in the search for vulnerable patients. It will also lead to the development and deployment of new therapies and ultimately to reduce the incidence of acute coronary syndromes and sudden cardiac death. We encourage healthcare policy makers to promote translational research for screening and treatment of vulnerable patients.

D-dimer, other markers of haemostasis activation and soluble adhesion molecules in patients with different clinical probabilities of deep vein thrombosis

Two automated turbidimetric D-dimer assays (BC D-dimer Plus, Dade Behring, Marburg, Germany and Auto-Dimer, Biopool, Umeå, Sweden) were compared to two enzyme-linked immunosorbent assays (ELISAs) (Enzygnost D-dimer micro, Dade Behring and Asserachrome D-dimer, Diagnostica Stago, Asnières, France) and two rapid D-dimer assays (SimpliRed, Agen Biomedical, Brisbane, Australia and Minutex, Biopool) in out-patients with suspected deep vein thrombosis (DVT). In addition, the performance of prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), and soluble adhesion molecules VCAM-1 and P-selectin for DVT diagnosis was assessed. One hundred and thirty-five consecutive out-patients with suspected DVT of the lower limb were included, and in 52 (39%), DVT was confirmed by compression ultrasound. All D-dimer assays investigated reliably excluded DVT in those patients without DVT irrespective of their pre-test clinical probability of DVT. One D-dimer ELISA (Dade Behring) gave the highest area under the receiver operating characteristic (ROC) curve compared to other assays, and therefore, this was the most accurate assay in differentiating patients with from patients without DVT. The diagnostic performance of one automated turbidimetric assay (Auto Dimer, Biopool) was similar to ELISA and its convenience close to rapid latex agglutination assays. Most patients with a high pre-test clinical probability of DVT had positive D-dimer regardless of the presence or absence of DVT, which decreased the specificity of the tests and made D-dimer determination less useful for this group of patients. Because the diagnostic accuracy [sensitivity, specificity, negative (NPV) and positive predictive value (PPV)] of F1+2, TAT, VCAM-1 and P-selectin was inferior to D-dimer assay, these assays could not substitute or supplement D-dimer testing in diagnosis of DVT. Levels of VCAM-1 and P-selectin were increased in patients with DVT and should therefore be investigated further to clarify their role in DVT.