Interleukin-6 and acute coronary syndrome

The designation of atherosclerosis as a chronic inflammatory process represents an exciting and logical paradigm shift for cardiologists. Plasma concentrations of interleukin-6 (IL-6) and its hepatic by-product C-reactive protein (CRP) appear to reflect the intensity of occult plaque inflammation and by inference may determine vulnerability to rupture. Indeed, circulating IL-6 levels are elevated in patients with acute myocardial infarction (AMI), and also in patients with unstable, but not with stable angina. Coronary sinus IL-6 concentrations are also increased after percutaneous coronary intervention (PCI), and late restenosis correlates with an increase in IL-6 concentration after the procedure, indicating that IL-6 expression may be not only related to instability of atheromatous plaques, but also to the formation of restenotic lesions after PCI. These observations suggest the advantage of screening for circulating IL-6 concentration and the use of anti-inflammatory treatment for those thought be at high risk to reduce the risk of future AMI.

Is low adiponectin levels more sensitive predictor of in-stent restenosis: new questions and challenges

Predicting in-stent restenosis has been subject of many investigations. Several candidates have also been proposed such as CRP. However, recent findings suggested that adiponectin may be a more sensitive marker for in-stent restenosis. These initial results should be confirmed by other large scale prospective trials.

[Antioxidant status and restenosis after stenting of coronary arteries]

AIM

To investigate possibility of effect of antioxidant status on severity of restenosis of coronary arteries after transluminal coronary angioplasty with stenting.

MATERIAL AND METHODS

Men with ischemic heart disease and coronary angiography performed in 6 months after coronary artery stenting with bare stents were included in this study. Coronary angiograms were subjected to quantitative computer analysis. Samples of venous blood were obtained before control angiography. We assessed duration of lag phase of copper induced free radical oxidation of low density lipoproteins (LDL), and measured level of lipoperoxides in LDL, content of malone dialdehyde (MDA) in LDL, activity of superoxide dismutase (SOD), glutathione peroxidase (GP), and erythrocyte catalase.

RESULTS

We revealed positive correlations of lag phase duration and activity of GP with minimal artery diameter 6 months after stenting (r=0.41, p < 0.002 and r=0.24, p < 0.05, respectively), of lipoperoxide level in LDL and MDA content in LDL with degree of stenosis (r=0.32, p < 0.009, and r=0.37, p < 0002, respectively). We also found negative correlations between lag phase duration and GP activity with degree of restenosis (r= - 0.38, p < 0.04, and r= - 0.39, p < 0.001, respectively), level of lipoperoxides in LDL and MDA content in LDL with artery minimal diameter (r= - 0.33, p < 0.007, and r=0.32, p < 0.008, respectively).

CONCLUSION

Our study confirms possibility of influence of antioxidant status on degree of coronary artery restenosis in patients after coronary artery stenting.

Increased glycated albumin and decreased esRAGE concentrations are associated with in-stent restenosis in Chinese diabetic patients

BACKGROUND

We investigated the impact of glycated albumin (GA) and endogenous secretory receptor for advanced glycation end products (esRAGE) and RAGE polymorphisms on occurrence of in-stent restenosis (ISR) in Chinese patients with type 2 diabetes.

METHODS

Four hundred nineteen patients with diabetes were divided, based upon the presence or absence of coronary artery disease (CAD) and ISR, into Group I (205 patients without CAD), Group II (128 patients with CAD but without ISR) and Group III (86 patients with ISR). One hundred fifty-two normal subjects were served as controls. Serum concentrations of GA and esRAGE were measured, and RAGE polymorphisms (-374T>A, -429T>C and G82S) were analyzed.

RESULTS

Serum GA concentration was higher and, in contrast, esRAGE concentration was lower in Group III than in the other groups (P<0.05). These two protein concentrations correlated closely with loss index (all P<0.01), and were independent risk factors for ISR in diabetic patients (P=0.01 and P=0.025, respectively). However, there were no differences in the allele and genotype frequencies in the 3 polymorphisms of RAGE gene between groups.

CONCLUSIONS

Increased GA and decreased esRAGE concentrations, but not -374T>A, -429T>C and Gly82Ser polymorphisms of RAGE gene, are associated with ISR in Chinese patients with type 2 diabetes.

Plasminogen activator inhibitor-1 predicts coronary in-stent restenosis of drug-eluting stents

BACKGROUND

We tested the hypothesis that plasma levels of plasminogen activator inhibitor-1 (PAI-1) are influenced by percutaneous coronary intervention (PCI) with the implantation of drug eluting stents (DES) and are able to predict the occurrence of in-stent restenosis (ISR).

METHODS AND RESULTS

PAI-1 active antigen plasma levels were determined in 75 patients before and 24 h after PCI with DES implantation. Patients with ISR after six to eight months (16%) showed significantly lower PAI-1 plasma levels before PCI (ISR, 11.7 +/- 8.1 ng mL(-1); non-ISR, 22.8 +/- 18.8 ng mL(-1); P <0.05). PAI-1 levels in the lowest tertile were associated with a 9.5-fold increased risk of ISR, independent of clinical risk factors, angiographic or procedural characteristics, compared to the highest tertile (P < 0.05). The induced change of PAI-1 active antigen 24 h after PCI was significantly higher in patients with ISR (ISR, +5.6 +/- 8.0 ng mL(-1); non-ISR, -3.2 +/- 12.1 ng mL(-1); P < 0.05) with positive correlation to late lumen loss (r = 0.30; P < 0.05).

CONCLUSIONS

ISR after DES implantation is significantly related to plasma levels of PAI-1 active antigen before and after PCI. If confirmed by larger multicenter studies, the determination of PAI-1 plasma levels might be clinically helpful in the identification of patients at high risk of developing of ISR, even after DES implantation.

Changes in CCR2 chemokine receptor expression and plasma MCP-1 concentration after the implantation of bare metal stents versus sirolimus-eluting stents in patients with stable angina

BACKGROUND

Although restenosis after successful coronary stenting is associated with changes in adhesion molecules and chemokines, it is unclear whether the differential effects of these molecules between a bare metal stent (BMS) and sirolimus-eluting stent (SES) may help to prevent coronary restenosis. The aim of this clinical study was to compare the expression levels of those molecules after elective placement of either a BMS or SES.

METHODS AND RESULTS

The subjects included 32 consecutive patients with stable angina who had undergone successful coronary stenting and who randomly received either a BMS (n=16) or SES (n=16). Quantitative angiographic analysis 6 months after stenting showed that the minimal lumen diameter was significantly greater in the SES as compared to the BMS group, while the percent diameter stenosis and in-stent lumen loss were significantly lower. Plasma monocyte chemotactic protein-1 (MCP-1) increased significantly after 14 days and 6 months and monocyte CCR2 expression increased 24 hr and 48 hr after stenting in the BMS but not the SES group. Changes in plasma MCP-1 (DeltaMCP-1) within 6 months after stenting correlated significantly with in-stent lumen loss. The DeltaMCP-1 (between 6 months and baseline) was significantly related only to the lumen loss (r=0.443, p=0.023), which suggests that the reduction of MCP-1 is the best contributor to decreased lumen loss.

CONCLUSIONS

These data suggest that reduction in MCP-1 production by SES may be one mechanism to prevent restenosis after coronary stenting.

[The role of cytokines in improvement of coronary restenosis risk stratification after endovascular stenting in patients with ischemic heart disease]

AIM

To evaluate diagnostic and prognostic significance of the levels of proinflammatory cytokines (IL-1, IL-6, TNF-alpha) in improvement of stratification, i.e. determination of coronary restenosis risk in patients with ischemic heart disease 18 months after coronary artery (CA) stenting. The patients were divided into two groups: group 1 consisted of 30 patients with ischemic heart disease and symptoms of anginal recurrence, 38 patients of group 2 had no recurrent coronary insufficiency. Baseline examination of 68 patients with ischemic heart disease and their examination 6-24 months (18.1 +/- 1.9 months) after CA stenting were performed.

RESULTS

High activation of the proinflammatory cytokines in patients with postinfarction cardiac dysfunction and after CA stenting is associated with a high rate of recurrent angina, deterioration of myocardial perfusion, progression of atherosclerosis in CA native bed. Restenosis of CA stents in patients after endovascular myocardial revascularization significantly more frequently correlates with elevated blood levels of IL-6 by 56.8% (p = 0.031). Patients with anginal recurrence caused by stent restenosis, progression of atherosclerosis in native CA developed high expression (10.2-58.1%) of TNF-alpha (p = 0.038) 18 months after endovascular revascularization. Repeated angioplasty is associated with multiple CA affection (k = 0.56, p = 0.004) and predilation before stenting (k = 0.3; p = 0.001).

CONCLUSION

Dynamics of proinflammatory cytokines (IL-1, IL-6 and TNF-alpha) is efficient to use in complex diagnosis for better stratification of CA restenosis risk in endovascular stenting of patients with coronary artery disease.

[Activities of circulating endothelial progenitor cells in patients with in-stent restenosis]

OBJECTIVE

To observe the number and activities of circulating endothelial progenitor cells (EPCs) in patients with in-stent restenosis.

METHODS

Peripheral blood samples were collected from 15 patients with angiographically restenosis, and 17 baseline characteristics-matched patients without angiographically restenosis (control group). Mononuclear cells were isolated by Ficoll density-gradient centrifugation and plated on dishes coated with human fibronectin. After 7 days in culture, the nature of EPCs was characterized with anti-CD34 and anti-KDR, specific surface antibodies of EPC, and confirmed further with the use of fluorescein isothiocyanate-labeled ulex europaeus agglutinin-I (FITC-UEA-I) and DiI (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine percolate)-labeled acetylated low-density lipoprotein (DiI-acLDL) by laser scanning confocal microscopy. The number of EPCs was counted in a blinded manner. EPCs were inoculated onto the culture plate and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide assay was used to measure the A value by enzyme labeling instrument to evaluate the proliferation. The migration of EPCs was assayed by scratch assay. EPC adhesion was performed by replating cells on fibronectin-coated dishes and then counting the adherent cells. Results The number of EPCs of the patients with in-stent restenosis was 4.97 +/- 1.42/well, significantly lower than that of the control group (17.2 +/- 3.90/well, P = 0.001). MTT assay showed that the proliferative activities of the in-stent restenosis group was 1.37 +/- 0.32 times the baseline value, significantly lower than that of the control group (2.01 +/- 0.62, P < 0.05). The number of migrating EPCs of the in-stent restenosis group was remarkably lower than that of the control group. There was no significant difference in the adherent activity between the two groups. Conclusion The number, proliferation activity, and migration activity of the EPCs patients with in-stent restenosis are all significantly lower, which may contribute to the mechanism of in-stent restenosis.

Serum resistin as a biological marker for coronary artery disease and restenosis in type 2 diabetic patients

BACKGROUND

Resistin is an adipocyte-secreted hormone. The relationship between circulating resistin concentrations and atherosclerotic coronary artery disease (CAD) in type 2 diabetic patients, if any, remains poorly understood. Serum resistin concentrations were investigated in type 2 diabetic patients with CAD (DMCAD), and compared with the concentrations in diabetics patients without CAD (diabetes mellitus, DM). Whether resistin levels are associated with increased restenosis rates in diabetic patients with CAD after successful coronary stenting was also investigated.

METHODS AND RESULTS

Fasting serum resistin, adiponectin, and leptin concentrations were measured in 45 DMCAD patients and 47 DM controls. The percutaneous coronary intervention study included 70 DMCAD patients, who underwent elective and successful coronary bare metal stent (BMS) implantation for the treatment of de novo lesions. Serum resistin concentrations were higher in the DMCAD patients than in the DM controls (5.75+/-3.21 vs 2.53+/-2.47 ng/ml, mean +/- SEM, p<0.001), and these differences were persistent regardless of age or body mass index. Insulin resistance indices, as assessed via homeostasis model assessment (HOMA-IR) correlated significantly with resistin concentrations (r=0.4, p<0.001). Resistin was an independent factor, and was associated with DMCAD in the multivariate analysis. In the percutaneous coronary intervention study, HOMA-IR was not associated with subsequent restenosis rates after BMS implantation in DMCAD patients. Pre-procedural serum resistin concentrations were higher in restenosis group than in the patients without restenosis.

CONCLUSIONS

Serum resistin may prove to be a useful biological marker for CAD and restenosis in patients with type 2 DM.

The influence of established genetic variation in the haemostatic system on clinical restenosis after percutaneous coronary interventions

Since activation of the haemostatic system is an important feature of the wound healing response triggered by arterial injury, variations in genes involved in thrombus formation may play a role in restenosis after percutaneous coronary interventions (PCI). Therefore, our aim was to examine the relationship between polymorphisms that are known to play a role in the haemostatic system and the risk of clinical restenosis in the GENetic DEterminants of Restenosis (GENDER) study, a multicenter prospective study design that enrolled 3,104 consecutive patients after successful PCI. Target vessel revascularization (TVR) was the primary endpoint. All patients were genotyped for six polymorphisms in the Factor II, Factor V, Factor VII and PAI-1 genes. The PAI-1 4G variant was associated with an increased risk of TVR. When compared to 5G/5G homozygotes, heterozygous patients were at higher risk for TVR (HR: 1.46, 95% CI: 1.05-2.03), whereas patients with the 4G/4G genotype had an even further increased risk (HR: 1.69, 95% CI: 1.19-2.41). In contrast, the factor V 506Gln (factor V Leiden) amino acid substitution was associated with a decreased risk of TVR (HR: 0.41, 95% CI: 0.19-0.86). Our findings indicate that polymorphisms in the factorV and PAI-1 genes may play a role in the process of restenosis.

Serum gamma-glutamyl transferase activity: A new marker for stent restenosis?

Stent restenosis remains the main limitation of percutaneous coronary intervention. Elevated serum gamma-glutamyl transferase (GGT) level is associated with an inflammatory response. We aimed to determine the correlation of stent restenosis with the serums level of GGT. One hundred and twenty patients (age 58.56+/-10.46 years, 66% male) with a history of coronary stent implantation and had undergone control coronary angiography (60 with restenosis and 60 without) were included. All had baseline serum GGT activity and were free of systemic and hepatobiliary disease. Median baseline serum GGT activity was significantly higher in patients with restenosis (34.00 U/L (24.00-47.75)) than in those without restenosis (21.00 U/L (17.25-26.7500)) (P<0.0001). Stent restenosis was identified in 38% of the patients with a serum GGT value >40 U/L and in 5% of patients with a serum GGT value <or=40 U/L (P<0.001). Serum C-reactive protein (CRP) and total bilirubin levels were significantly higher (P=0.011 and 0.037, respectively) and alkaline phosphatase levels were significantly lower in patients with restenosis (P=0.029). Levels of GGT, CRP, and alkaline phosphatase were independent predictors of restenosis (P=0.001, 0.019 and 0.004, respectively). In conclusion, the serum level of GGT may be an independent marker for stent restenosis.

Serum C-reactive protein response to percutaneous coronary intervention in patients with unstable or stable angina pectoris is associated with the risk of clinical restenosis

BACKGROUND

Inflammation plays a pivotal role in the pathogenesis of atherosclerosis. Previous reports have used vaccination as a model to stimulate inflammation. The aim of the present study was to investigate the role of C-reactive protein response to PCI in the risk of clinical restenosis or new coronary stenosis, considering PCI as a model to stimulate inflammation.

MATERIAL AND METHODS

Eight hundred and ninety-one patients with stable or unstable angina pectoris and with normal serum troponin T<or=0.03 microg/L before PCI were investigated. The survivors after a follow-up period of 2.6 years (850 patients) were included. Serum CRP and troponin T concentration were measured before and the day after PCI. Restenosis and new coronary stenosis, detected by coronary angiography due to symptomatic coronary heart disease, were determined.

RESULTS

CRP response to PCI, unstable angina pectoris, the number of vessels dilated and lack of stent implantation were associated with restenosis or new coronary stenosis. In multivariate analysis, patients in the highest tertile of CRP, induced by PCI, had an increased risk (risk ratio 1.7 [95% CI 1.1-2.9]) for restenosis or new coronary stenosis. Furthermore, patients with restenosis had an increased CRP response to PCI compared with those with new coronary stenosis.

CONCLUSION

The CRP response to PCI, as a model to stimulate inflammation, is associated with an increased risk of clinical restenosis. The results emphasize the role of CRP in the pathogenesis of coronary artery disease progression and in particular restenosis.

Plasminogen activator inhibitor-1 and restenosis

Despite the introduction of drug-eluting stents restenosis remains an important clinical problem. In this review we examine the role of plasminogen activator inhibitor-1 (PAI-1) in controlling restenosis after balloon angioplasty and stent implantation.

Predictors of aorto-saphenous vein bypass narrowing late after coronary artery bypass grafting

The objective of this study was to evaluate the clinical and angiographic factors associated with significant saphenous vein graft (SVG) atherosclerosis progression at mid-term follow-up in a series of unselected coronary patients who had previously received a coronary artery bypass graft (CABG). A total of 123 SVGs from 86 patients who underwent cardiac catheterization twice, 15 +/- 12 months apart, were included in the study. None of the SVGs presented any > or =50% diameter stenosis (DS) lesion or underwent any intervention at baseline. All SVGs were divided into 3 segments and each SVG segment was scored from 0 to 3 depending on the presence of lesions, with percent DS ranging from 0% to 19% (score 0), 20% to 29% (score 1), 30% to 39% (score 2), and > or =40% (score 3). The SVG atherosclerotic burden score (ABS) was calculated by adding the score obtained for each of the 3 SVG segments. Significant progression was defined as > or =10% increase in lesion percent DS or > or =0.6 mm decrease in minimal lumen diameter between baseline and follow-up studies. Mean age of the study population was 66 +/- 9 years, and most of the patients were receiving statin therapy with mean low-density lipoprotein cholesterol of 85 +/- 26 mg/dl. Significant angiographic progression occurred in > or =1 SVG in 41 patients (48%). On multivariate analysis, the variables associated with SVG atherosclerosis progression were SVG ABS (odds ratio [OR], 1.52 for each increase of 1 point in SVG ABS; 95% confidence interval [CI] 1.1 to 2.29) and high-density lipoprotein (HDL) cholesterol (OR 1.38 for each decrease of 5 mg/dl in HDL cholesterol levels, 95% CI 1.09 to 1.85). Twenty-two patients (26%) had a cardiac event at follow-up related to SVG disease progression. The percent DS of the SVG segment at baseline was associated with SVG disease progression leading to a cardiac event (OR 3.67 for each increase of 5% in percent DS, 95% CI 2.11 to 6.38). In conclusion, simple clinical and angiographic variables such as HDL cholesterol, ABS, and lesion severity remain independent predictors of significant SVG atherosclerosis progression in mild to moderately diseased SVGs despite mean low-density lipoprotein levels <90 mg/dl.

Usefulness of preprocedural N-terminal pro-brain natriuretic peptide in predicting angiographic no-reflow phenomenon during stent implantation in patients with ST-segment elevation acute myocardial infarction

The no-reflow phenomenon after primary percutaneous coronary intervention (PCI) is associated with larger infarct size, worse functional recovery, and higher incidence of complication after acute ST-elevation myocardial infarction (STEMI). The aim of this study was to assess the relation between preprocedural N-terminal pro-brain-type natriuretic peptide (NT-pro-BNP) and angiographic no-reflow phenomenon. We measured preprocedural serum NT-pro-BNP level in 159 consecutive patients with acute STEMI (aged 63 +/- 12 years; 72% men) before PCI. Angiographic no-reflow after PCI was defined as Thrombolysis In Myocardial Infarction (TIMI) flow grade <3. Baseline characteristics, including time from chest pain onset, between the no-reflow (n = 67) and normal-reflow groups (n = 92) were similar. NT-pro-BNP was significantly higher in the no-reflow group than the normal reflow group (1,982 +/- 3,314 vs 415 +/- 632 pg/ml; p = 0.005). Also, high-sensitivity C-reactive protein, monocytes, and troponin-T were significantly higher in the no-reflow group than the normal-reflow group. In the no-reflow group, NT-pro-BNP was much higher in patients with TIMI flow grade 0 (n = 41; 2,290 +/- 3,495 pg/ml) than those with TIMI grade 1 or 2 (n = 26; 1,575 +/- 2,340 pg/ml), but without significant difference. The area under the receiver-operating characteristic curve for NT-pro-BNP was 0.78, and the optimal cut-off value identified using receiver-operating characteristic curve analysis was 500 pg/ml. At the standard cut-off value of >500 pg/ml, increased NT-pro-BNP showed a high probability of no-reflow phenomenon (odds ratio 4.42, 95% confidence interval 1.15 to 17.00, p = 0.028). In conclusion, preprocedural NT-pro-BNP may be a strong predictor of the development of no-reflow phenomenon after PCI in patients with acute STEMI.

High P-selectin expression and low CD36 occupancy on circulating platelets are strong predictors of restenosis after coronary stenting in patients with coronary artery disease

Recent studies have shown that circulating platelets play an important role in the development of restenosis early after coronary stent implantation. We investigated P-selectin expression and CD36 blockade on platelets by flow cytometry in 48 consecutive patients who underwent coronary stenting. P-selectin expression was significantly higher 1 day after stenting in patients who had restenosis (n = 15) than in those who had no restenosis (n = 28), and the odds ratio for restenosis in patients with high P-selectin levels (MFI > 6.5) was 11.67 (P < 0.001) as compared with patients who had intermediate and low P-selectin levels. CD36 blockade was assessed with the use of two anti-CD36 antibodies, OKM5 and GS95 (our new anti-CD36 antibody), the binding of which indicates total CD36 amount and free CD36 unoccupied by lipid-related ligands, respectively. Binding of OKM5 to platelets was similar before and after stenting in both groups. CD36 blockade on platelets was seen 1 day after stenting in the non-restenosis group, and the odds ratio for restenosis in patients without CD36 blockade [GS95 binding ratio >0.8 as compared with binding before stenting] on day 1 was 28.60 (P < 0.001). P-selectin expression and unoccupied CD36 on platelets shortly after stenting may be strong predictors of post-stent restenosis.

Pentraxin3 is a novel marker for stent-induced inflammation and neointimal thickening

Inflammation in the injured vessel wall plays an essential role in the mechanism of restenosis. Pentraxin3 (PTX3) is synthesized at the inflammatory site in response to primary inflammatory stimuli. To establish the clinical significance of plasma PTX3 levels in the pathophysiology of inflammation in the injured vessels, we serially measured the levels in 20 patients undergoing elective coronary stenting. Plasma PTX3 levels increased 15 min after coronary stenting, and reached a maximum at 24h in the coronary sinus (P<0.001 versus baseline) and peripheral blood (P<0.001 versus baseline). The transcardiac gradient of PTX3 at 15 min after PCI was higher in patients with than those without restenosis (0.40+/-0.64 versus -0.19+/-0.33 ng/ml, P=0.02). Furthermore, the increase in PTX3 at 24h was positively correlated with the increase in activated Mac-1 on the surface of neutrophils at 48 h (r=0.48, p<0.05) in the coronary sinus. Stepwise multiple regression analysis demonstrated that the relative increase in PTX3 at 24h was the most powerful predictor of late lumen loss (r=0.547, P=0.007). Coronary stenting enhanced circulating PTX3 levels in association with an inflammatory response. PTX3 may be a useful marker for evaluation of inflammatory reaction and neointimal thickening after vascular injury.

Enhanced inflammatory response to coronary stenting marks the development of clinically relevant restenosis

OBJECTIVES

The aims of this study were to investigate the effect of coronary stenting on the release of cytokines and cell-mediated immunity factors and to evaluate the association between inflammation and clinical outcomes at 6 months.

BACKGROUND

Circulating levels of inflammatory markers and cytokines are elevated in patients with acute coronary syndromes and are related to an unfavorable outcome. The aims of this study were to investigate the effect of coronary stenting on the release of cytokines and cell-mediated immunity factors and to evaluate the association between inflammation and clinical outcomes at 6 months.

METHODS

Forty patients with single native coronary artery disease treated with stenting were enrolled. Peripheral venous blood samples were collected before and 6 h, 48 h, and 12 weeks after stenting. Serum concentrations of high-sensitivity C-reactive protein, interleukin-6, interleukin-8, tumor necrosis factor-alpha (markers of inflammation) and serum-soluble interleukin-2 receptor for T-lymphocyte activation (sIL2-R, marker of cell-mediated immunity) were measured. Patients also were evaluated clinically one, 3, and 6 months post-stenting or when they presented with cardiovascular symptoms to identify major adverse cardiac events (cardiac death, MI, revascularization).

RESULTS

Concentrations of interleukins 6 and 8 and tumor necrosis factor-alpha peaked at 6 h (11.0, 12.6, and 5.3 pg/ml, respectively). The peak level of high-sensitivity C-reactive protein (2.77 mg/dL) occurred 48 h post stenting, while sIL2-R peaked (495 U/ml) at 12 weeks. Patients who experienced restenosis had higher levels of C-reactive protein at 48 h (4.94 vs. 1.84 mg/dl; P = 0.043) and of IL-8 at 6 h (26.75 vs. 13.55 pg/mL; P = 0.048) than those without restenosis.

CONCLUSIONS

Proinflammatory cytokines and inflammatory markers are released into the peripheral circulation early after coronary stenting, and increased levels of some are associated with clinically relevant restenosis.

Predictive value of preintervention C-reactive protein on clinical outcome after directional coronary atherectomy followed by stent implantation

BACKGROUND

Preprocedural C-reactive protein (CRP) serum levels have been shown to predict the recurrence of angina or major adverse cardiac events after percutaneous coronary intervention. Directional coronary atherectomy (DCA), by reducing residual plaque burden and restenosis, has been shown to improve clinical outcome after coronary stenting. Thus, we assessed the influence of preprocedural CRP serum levels on the recurrence of cardiac events after DCA followed by bare metal stent implantation.

METHODS

We enrolled 40 consecutive patients (34 males; 61+/-10 years old) with single-vessel disease who were undergoing DCA. In all patients, preprocedural CRP serum levels were measured by an ultrasensitive nephelometric method. The endpoint of the study was defined as the composite incidence of death, myocardial infarction, and recurrence of angina requiring repeat revascularization at 6-month follow-up.

RESULTS

CRP serum levels were a significant independent predictor of the composite endpoint at multiple regression analysis [odds ratio=1.69; 95% confidence interval (95% CI)=1.04-2.75; P=.033]. Patients with recurrence of cardiac events had CRP serum levels higher than those of patients not having events on follow-up [3.95 (2.2-5.7) vs. 2 (1.3-3.3); P=.05].

CONCLUSION

In conclusion, our study shows that baseline CRP serum levels predict cardiac events after coronary bare metal stenting despite plaque debulking with directional atherectomy.

Adiponectin incompletely prevent MCP-1-dependent restenosis after percutaneous coronary intervention [corrected] in patients with coronary artery disease

BACKGROUND

Some factors play pathogenic roles in the development of restenosis after percutaneous coronary intervention (PCI). We measured and compared the ratio of elevated levels of monocytic chemotactic peptide-1 (MCP-1), regulated on activation normally T-cell expressed and secreted (RANTES), soluble (s) P-selectin, sE-selectin and adiponectin after PCI.

METHODS

Plasma levels of chemokines and soluble markers were measured before and 30 days after PCI in 96 patients (69 males and 27 females, aged 63 +/- 9 years) who underwent PCI and who had repeated angiograms at a 6-month follow-up. In addition, we carried out the basic study of the tissue factor expression on monocytic cell line (THP-1) by MCP-1.

RESULTS

Restenosis occurred in 33 (34.4%) patients. A significant and time-dependent increase in MCP-1 was observed in the restenosis group. However, there were no significant differences in RANTES, sP-selectin, and sE-selectin levels with or without restenosis. Adiponectin levels in patients with coronary artery disease were significantly lower than levels in normal controls. However, adiponectin levels were no different at baseline between patients with or without restenosis. MCP-1 did not induce the expression of tissue factor on THP-1. However, the recombinant sCD40 ligand-induced expression of tissue factor on THP-1 was enhanced by the addition of MCP-1.

CONCLUSION

These findings suggest that restenosis development after PCI in patients with coronary artery disease may involve the participation of MCP-1 after PCI, and adiponectin incompletely prevent this MCP-1-dependent restenosis.

Prognostic impact of preprocedural C reactive protein levels on 6-month angiographic and 1-year clinical outcomes after drug-eluting stent implantation

OBJECTIVE

To determine the association of preprocedural C reactive protein (CRP) levels with angiographic restenosis and adverse clinical events after drug-eluting stent (DES) implantation.

DESIGN

A prospective cohort analysis of preprocedural CRP levels as a predictor of serious ischaemic complications or binary restenosis in patients treated with DES.

SETTING

Tertiary referral centre.

PATIENTS

1650 consecutive patients who underwent successful DES implantation. Patients were grouped into tertiles according to preprocedural CRP values for data analysis.

INTERVENTIONS

Successful DES implantation.

MAIN OUTCOME MEASURES

The primary end point was a major coronary event, defined as cardiac death or Q-wave myocardial infarction.

RESULTS

Baseline clinical and angiographic characteristics were similar between the tertile groups, except that more patients had multivessel disease and acute coronary syndrome with increasing tertiles of CRP levels. At 1-year follow-up, a primary end point occurred in 4 (0.7%) patients of the lowest tertile, in 3 (0.5%) patients of the middle tertile and in 16 (2.9%) patients of the highest tertile (p = 0.003). In multivariate analysis, the highest tertile of CRP levels was an independent predictor of a major coronary event (HR 4.68, 95% CI 1.91 to 11.44, tertile III vs tertiles I and II, p = 0.001). However, restenosis rates were similar in all three groups (9.1% vs 11.4% vs 11.6%, respectively, p = 0.3).

CONCLUSIONS

Preprocedural CRP levels are significantly associated with major coronary events after DES implantation. However, preprocedural CRP levels do not predict subsequent restenosis. Baseline CRP levels may be useful to guide adjunctive management for preventing serious ischaemic events in patients undergoing DES implantation.

Effect of atorvastatin and pravastatin on platelet inhibition by aspirin and clopidogrel treatment in patients with coronary stent thrombosis

We sought to determine a potential interaction between statins and antiplatelet therapy with aspirin and clopidogrel. Previous laboratory studies have shown a possible drug-drug interaction of statins metabolized by cytochrome P450 3A4 and clopidogrel (prodrug metabolized by cytochrome P450 3A4), resulting in an impaired inhibitory effect of clopidogrel on platelet aggregation. However, conclusive prospective data assessing this potentially relevant interaction are lacking. In 73 patients, 23 with previous coronary stent thrombosis (ST) (ST group) and 50 without coronary ST (control group), platelet aggregation was measured 3 times in monthly intervals using light transmission aggregometry (adenosine diphosphate [ADP] and arachidonic acid induction). Measurements were carried out with aspirin monotherapy (100 mg/day), dual antiplatelet therapy with aspirin plus clopidogrel (75 mg/day), and additional treatment of 20 mg/day of atorvastatin or 40 mg/day of pravastatin. ADP (5 and 20 micromol)-induced platelet aggregation was significantly decreased with clopidogrel (p <0.001) but remained stable under additional treatment with atorvastatin or pravastatin in the 2 groups. Patients with previous ST showed a higher ADP-induced aggregation level than control subjects. This difference was not influenced by clopidogrel or statin treatment. In conclusion, patients with previous ST show a higher aggregation level than control subjects independent of statin treatment. Atorvastatin and pravastatin do not interfere with the antiaggregatory effect of aspirin and clopidogrel. In conclusion, drug-drug interaction between dual antiplatelet therapy and atorvastatin or pravastatin seems not to be associated with ST.

Mobilization of CD34-positive bone marrow-derived cells after coronary stent implantation: impact on restenosis

BACKGROUND

Recently, accumulating evidence has indicated that bone marrow-derived stem cells are capable of differentiating into vascular cells. It has been hypothesized that the inflammatory response after vascular injury triggers the mobilization of endothelial and smooth muscle progenitor cells from bone marrow.

METHODS AND RESULTS

We measured circulating CD34-positive mononuclear cells, activation of integrin Mac-1 on the surface of neutrophils, and plasma granulocyte-colony stimulating factor levels in 40 patients undergoing coronary stenting. After bare-metal stenting, CD34-positive cells increased, reaching a maximum on day 7 after stenting. The maximum change compared with baseline before stenting was more striking in patients with restenosis than without restenosis (332+/-108% versus 148+/-49%; P<0.05). In contrast, CD34-positive cells decreased after sirolimus-eluting stenting (72+/-21% on day 7). The change in CD34-positive cells on day 7 relative to baseline was closely correlated with that in activated Mac-1 at 48 hours (R=0.52, P<0.01) and that in granulocyte-colony stimulating factor levels at 24 hours (R=0.42, P<0.05). Cell culture assay on day 7 showed that mononuclear cells differentiated into CD31-positive endothelium-like cells after bare-metal stenting. In patients with restenosis, mononuclear cells differentiating into alpha-smooth muscle actin-positive smooth muscle-like cells also were observed. Implantation of sirolimus-eluting stents suppressed both types of differentiation.

CONCLUSIONS

Stent implantation may induce differentiation of bone marrow cells into endothelial or smooth muscle cells. Endothelial cells may participate in reendothelialization, a protective reaction against vascular injury, whereas smooth muscle cells may participate in neointimal thickening and restenosis. Sirolimus-eluting stents appear to inhibit the mobilization and differentiation of bone marrow cells.

Increased circulating platelet-derived microparticles are associated with stent-induced vascular inflammation

Inflammation as well as platelet activation at the site of local vessel-wall injury plays an essential role in the mechanism of restenosis after Percutaneous coronary intervention (PCI). Platelet-derived microparticles (PDMPs) released from activated platelets are thought to play a role in the inflammatory process, possibly interacting with leukocyte integrin Mac-1. We serially measured circulating PDMPs, high-sensitive C-reactive protein (hs-CRP) and activated Mac-1 on the surface of neutrophils in 61 patients undergoing coronary stenting. PDMPs, hs-CRP and Mac-1 increased after coronary stenting in a time-dependent manner with the maximum response at 48 h in coronary sinus blood (PDMPs: 10.3+/-8.9-32.8+/-13.8 U/ml; P<0.001, hs-CRP: 0.27+/-0.23-1.46+/-0.99 mg/dl; P<0.001, activated Mac-1, 134+/-19% relative increase, P<0.001). PDMPs were correlated with hs-CRP (R=0.58, P<0.001) and the relative increase in Mac-1 (R=0.69, P<0.001) 48 h after coronary stenting. Multiple regression analysis showed that each of PDMPs (R=0.40, P<0.05), hs-CRP (R=0.33, P<0.05) and Mac-1 (R=0.48, P<0.01) was an independent predictor of the late lumen loss. Coronary stenting enhanced circulating PDMPs in association with an inflammatory response in the injured vessel wall. PDMPs may be a useful marker for evaluation of stent-induced inflammatory status and a powerful predictor of restenosis equivalent to activated Mac-1.

Periprocedural soluble P- and E-selectin levels fail as predictors of clinical restenosis in patients treated with elective coronary stenting

An increasing amount of basic scientific data indicates that adhesion molecules may be involved in the pathogenesis of vessel re-narrowing in patients undergoing coronary angioplasty. Furthermore, inflammation is suggested to be a pivotal mechanism linking atherosclerosis and restenosis. The aim of this study was to assess if periprocedural evaluation of soluble P-selectin (sP-selectin) and E-selectin (sE-selectin) possesses any additive value in the restenosis prediction to C-reactive protein (CRP) measurement. One hundred and nine stable angina patients were consecutively enrolled into the prospective cohort study. All participants were treated with single vessel coronary bare metal stenting. sP-selectin, sE-selectin and CRP were measured in peripheral venous blood samples collected before and 6, 24 h and 1 month after the procedure. Clinical follow-up visits were held 7 days(*), 1(*), 3, 6(*), and 12 months ((*)with an exercise test) after stenting. Any symptoms of restenosis were verified angiographically. Clinical restenosis occurred in 18 subjects. Concentrations of sP-selectin and sE-selectin did not differ between patients with and without clinical restenosis at any measuring point. In the latter group a decrease in sP-selectin and sE-selectin levels was observed 6 h after stenting. These findings when considered in all of the investigated subjects had no impact on the subsequent incidence of restenosis. An inflammatory response assessed as an increase in CRP level with the peak values at 24 h was noted in the whole population. However, it was significantly more pronounced in the restenosis group. Application of the Cox's proportional hazard model revealed a high CRP level 24 h after stenting and the history of coronary angioplasty concerning a nontarget lesion to be the only independent predictors of clinical restenosis. To conclude, the periprocedural evaluation of sP-selectin and sE-selectin in peripheral venous blood in patients undergoing elective coronary stenting provides no prognostic information in terms of clinical restenosis prediction, and the magnitude of the systemic inflammatory response triggered by coronary angioplasty assessed as an increase in CRP level and the history of coronary angioplasty concerning nontarget stenosis remain independent predictors of lesion re-narrowing.

Is inflammation a contributor for coronary stent restenosis?

The development of coronary stent has revolutionized the field of interventional cardiology by reducing the incidence of restenosis after balloon angioplasty. Despite significant progress in its prevention and treatment, however, in-stent restenosis (ISR) is still common, and remains a challenge for the interventional cardiologist. Restenosis after stent implantation is mainly caused by neointimal proliferation through the stent struts. Currently, there are three major factors has been demonstrated to be contributors for ISR, namely patients-, lesion- and genetic-related factors in large number of clinical trials. However, the triggers and pathophysiological mechanisms for ISR are not fully elucidated. Experimental as well as clinical studies indicate a marked activation of inflammatory cells at the site of stent structs, which are likely to play a key role in the process of neointimal proliferation and stent restenosis. Those data suggest that inflammation may be a major contributor for ISR. In fact, coronary stenting is a strong inflammatory stimulus and the acute systemic response to local inflammation produced by coronary stenting is highly individual and predicts restenosis and event-free survival. Thus, the attention should be paid on anti-inflammatory therapeutic approaches for ISR, and the benefit of anti-inflammatory therapy during the periprocedural period and long-term follow-up is dependent on the inflammatory status. Measurement of cytokine and acute phase proteins, such as C-reactive protein, therefore, may be important to identify high-risk subjects and develop specific treatment tailored to the individual patients.

Monocyte chemoattractant protein-1 and coronary artery disease

The designation of atherosclerosis as a chronic inflammatory process represents an exciting and logical paradigm shift for cardiologists. Monocyte chemoattractant protein-1 (MCP-1) plays an important role in the recruitment and activation of monocytes and thus in the development of atherosclerosis. Enhanced MCP-1 expression has been detected in macrophages, endothelial cells, and vascular smooth muscle cells in the atheromatous plaque. Activation of macrophages by MCP-1 also appears to be involved in the vulnerability of the plaque. Indeed, circulating MCP-1 levels are elevated in patients with acute myocardial infarction and in those with unstable angina, but not in patients with stable angina. Production of MCP-1 and macrophage accumulation are also observed after coronary angioplasty or grafting, indicating that MCP-1 expression may be related not only to instability of atheromatous plaques, but also to the formation of restenotic lesions. The development of therapeutic drugs for atherosclerosis targeted specially against MCP-1 may be useful in the prevention of plaque formation and future myocardial infarction.

One month follow-up C-reactive protein may be a useful predictor of angiographic restenosis and long-term clinical outcomes after bare metal stent implantation

We report C-reactive protein (CRP) measured 1 month after stenting was an independent predictor of angiographic restenosis, and patients with both elevated preprocedural CRP and CRP 1 month after stenting had the worst long-term clinical outcomes. Measurement of CRP during follow-up in addition to preprocedural CRP may improve risk stratification after coronary stenting.

Clinical applications of circulating oxidized low-density lipoprotein biomarkers in cardiovascular disease

PURPOSE OF REVIEW

The aim of this article is to review, analyze and interpret the growing body of evidence on circulating oxidized low-density lipoprotein and its relationship to diagnosis and prognosis of cardiovascular disease.

RECENT FINDINGS

Previous studies focused on indirect measures of oxidative stress such as susceptibility of low-density lipoprotein to oxidation and measurement of autoantibodies to oxidized low-density lipoprotein. The generation of monoclonal antibodies recognizing distinct oxidation-specific epitopes has allowed the development of sensitive and specific assays to measure circulating oxidized low-density lipoprotein. Recent work in human populations has demonstrated that circulating oxidized low-density lipoprotein is associated with preclinical atherosclerosis, coronary and peripheral arterial atherosclerosis, acute coronary syndromes and vulnerable plaques. Several studies have also suggested that elevated levels of oxidized low-density lipoprotein are a prognostic indicator of cardiovascular outcomes. In addition, it has been shown that lipoprotein(a) is the primary carrier of oxidized phospholipids in the circulation of humans, suggesting additional mechanisms through which lipoprotein(a) may be pro-atherogenic.

SUMMARY

Research on circulating oxidized low-density lipoprotein biomarkers is rapidly accelerating and providing novel insights into the pathophysiology of cardiovascular disease. Future studies will further assess the clinical utility of oxidized low-density lipoprotein biomarkers by determining their prognostic value in the diagnosis and prognosis of cardiovascular disease and will also evaluate the relative merit of specific assays by performing comparative studies.

Redox imbalance in patients with coronary artery disease showing progression of atherosclerotic lesions

OBJECTIVES

To clarify the relationship between changes in redox balance and the development of new coronary lesions in patients with coronary artery disease (CAD).

METHODS

We studied 82 CAD patients (70 males and 12 females, mean age 61.8 +/- 9.2 years) who underwent repeated coronary angiography within 1 year after percutaneous coronary intervention. Levels of serum lipid peroxide, erythrocyte glutathione peroxidase activity, and the redox state of erythrocyte (ratio of reduced to oxidized glutathione, the GSH/GSSG ratio) were measured at the time of follow-up coronary angiography. According to the development of significant stenotic lesions, we divided the patients into two groups: 57 patients without the development of new stenotic lesions (group A) and 25 patients showing new significant stenotic lesions within 1 year (group B).

RESULTS

The serum lipid peroxide level in group B was significantly higher than those of group A (2.61 +/- 0.32 vs 1.74 +/- 0.16 nmol/ml, p < 0.01). Erythrocyte glutathione peroxidase activity did not differ significantly between two groups. The erythrocyte GSH/GSSG ratio in group B was significantly lower than that of group A (83 +/- 9.6 vs 126 +/- 7.3, p < 0.01). The sensitivity and specificity of GSH/GSSG ratio to detect CAD patients with the development of significant coronary stenosis were 80.0% and 61.4%, respectively.

CONCLUSIONS

CAD patients who showed development of new coronary lesions within 1 year have increased oxidative stress and imbalanced erythrocyte redox state. The GSH/GSSG ratio, an indicator for redox balance, could be a useful marker to identify high-risk CAD patients.

Close association of regional interleukin-6 levels in the infarct-related culprit coronary artery with restenosis in acute myocardial infarction

BACKGROUND

The involvement of interleukin (IL)-6 in restenosis of the recanalized coronary artery after the percutaneous coronary intervention (PCI) was examined.

METHODS AND RESULTS

There were 40 patients enrolled in the study who had acute myocardial infarction and whose infarct-related coronary arteries were treated by new thrombectomy devices and stenting. Blood samples were collected from the culprit coronary artery before and immediately after the maneuver of the PCI. Restenosis was defined as residual stenosis because it accounted for more than 50% at the follow-up coronary angiography. Plasma IL-6 levels in the infarct-related coronary artery were 12.8 and 13.2 pg/ml before and after the initial maneuver of the PCI, respectively, values that were significantly greater than that of 7.2 pg/ml in the peripheral vein (p<0.0001). The levels of IL-6 in the pre- and the post-stage of PCI were significantly greater in the patients with restenosis than those without restenosis. The plasma IL-6 levels in the post-stage of PCI had significant correlations with late loss and loss index.

CONCLUSIONS

The present study findings indicate that plasma IL-6 levels in the culprit coronary artery at the post-stage of PCI are closely associated with the future restenosis of the revasculized coronary artery in acute myocardial infarction.

677TT polymorphism of methylenetetrahydrofolate reductase in combination with low serum vitamin B12 is associated with coronary in-stent restenosis

BACKGROUND

Recent studies have shown that a common mutation (nucleotide 677 C-->T) in the methylenetetrahydrofolate reductase (MTHFR) gene may contribute to a mild rise in plasma homocysteine levels and increase the incidence of coronary artery disease. Therefore, this study was designed to further investigate whether the effects of MTHFR 677 C to T mutation, plasma homocysteine, serum vitamin B12, and folate can influence restenosis after successful coronary stenting.

METHODS AND RESULTS

We investigated 260 patients each with a lesion after successful coronary stent placement. All patients received a repeated angiography after 6 months, or earlier if clinically indicated. Angiographic in-stent restenosis (ISR) was defined as >or=50% diameter stenosis at follow-up. Genotyping for MTHFR was based on a polymerase chain reaction technique. Also fasting plasma homocysteine, vitamin B12, and folate levels were measured at the same time. The ISR rate was higher among the patients with the TT genotype than in those with the non-TT genotypes (64.0% versus 32.9%, P=0.002). There was no significant difference in plasma homocysteine levels among patients with the TT genotype and patients with the non-TT genotypes (15.9+/-7.6 versus 15.5+/-6.6 micromol/L, P=0.75). However, among the patients with the TT genotype, those with higher plasma homocysteine levels (>or=12 micromol/L) demonstrated a significantly higher ISR rate (75.0% versus 33.5%, P=0.001). Logistic regression analysis revealed that the combined presence of the MTHFR TT genotype and lower than average serum vitamin B12 (>or=550 pg/mL) resulted in the most significant difference in the risk of ISR (OR=3.57, CI=1.51-8.46, P=0.004; OR=2.36, CI=1.35-4.15, P=0.003).

CONCLUSIONS

MTHFR 677TT polymorphism and low serum vitamin B12 each individually increased the risk of coronary ISR. Furthermore, the combination of these parameters resulted in a greater increase in risk.

Relationship between preheparin lipoprotein lipase mass concentration in serum and bare metal stent restenosis

OBJECTIVES

Insulin resistance or inflammation is known to be related with lipoprotein lipase activity and these factors are also closely associated with the pathogenesis of bare-metal stent restenosis. This study examined the relationship between preheparin lipoprotein lipase protein (preheparin LpL mass) concentration in serum and bare-metal stent restenosis.

METHODS

A total of 121 lesions in 112 patients who underwent bare-metal stent implantation using NIR stent or S660/670 stent were examined. Subjects were divided into two groups (N group; patients with normal preheparin LpL mass concentration, n = 50 or L group; patients with low preheparin LpL mass concentration, n = 71) according to the mean levels of preheparin LpL mass concentration (male 39.3 ng/ml, female 50.6 ng/ml).

RESULTS

There were no differences in percutaneous coronary intervention or angiographical characteristics. The L group had a significantly higher incidence of restenosis rate and target lesion revascularization than the N group (N group vs L group: 8.0% vs 42.3%, p < 0.0001; 8.0% vs 33.8%, p = 0.0008, respectively). Homeostatic model assessment of insulin resistance as a marker of insulin resistance and high sensitive C-reactive protein concentration were significantly higher in the L group than the N group. Multiple regression analysis showed that only low preheparin LpL mass concentration was an independent factor for restenosis (t value = 3.6, p = 0.0005).

CONCLUSIONS

Preheparin LpL mass concentration is closely associated with bare-metal stent restenosis and preheparin LpL mass concentration may be an important marker for the selection of bare-metal stent or drug-eluting stent.

The presence of metabolic syndrome is independently associated with elevated serum CD40 ligand and disease severity in patients with symptomatic coronary artery disease

Nontraditional atherosclerotic risk factors have become the focus of attention in recent years. In addition, metabolic syndrome is gaining recognition as another multiplex cardiovascular risk factor. However, to date, no studies have investigated the effect of metabolic syndrome on circulating soluble CD40 ligand (sCD40L), monocyte chemoattractant protein 1, cellular adhesion molecules, and disease severity in patients with symptomatic coronary artery diseases. This study was conducted to address this issue. Patients with stable angina who received percutaneous coronary interventions for significant (> or = 70% diameter stenosis) de novo lesions between January 1999 and January 2004 and had preprocedural serum samples were enrolled. Metabolic syndrome was defined by the National Cholesterol Education Program criteria with waist criterion modified into body mass index of more than 25 kg/m2. The serum samples were thawed and analyzed for circulating sCD40L, monocyte chemoattractant protein 1, adhesion molecules, and high sensitivity C-reactive protein (hs-CRP). Coronary severity was assessed by a modified version of Gensini scoring system. A total of 313 patients, 248 males and 65 females, were studied. Among them, 222 (70.9%, 170 males and 52 females) had metabolic syndrome. Patients with metabolic syndrome had higher serum creatinine level and lower low-density lipoprotein cholesterol despite higher triglyceride concentration. In multivariate analysis, patients with metabolic syndrome had higher sCD40L (6057 +/- 275 vs. 5051 +/- 423 pg/mL, P = .037) and more hs-CRP in higher tertiles (P = .005) than patients without, but similar levels of intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and P selectin. Metabolic syndrome was also significantly associated with multiple coronary vessel involvements with 70% or higher diameter stenosis (36.5% double-vessel and 14% triple-vessel diseases vs 30.8% double-vessel and 5.5% triple-vessel diseases, P = .026) and multiple coronary segment involvements with 50% or higher diameter stenosis (P = .014) in multivariate analysis. In conclusion, the presence of metabolic syndrome is independently associated with elevated sCD40L, hs-CRP, and coronary disease severity in patients with coronary artery disease requiring interventional treatment of stable angina.

Relation of soft plaque and elevated preprocedural high-sensitivity C-reactive protein levels to incidence of in-stent restenosis after successful coronary artery stenting

Although various predictors relating to in-stent restenosis (ISR) have been demonstrated, the relation between the parameters of intravascular ultrasound and inflammatory markers and ISR has not been reported. This study included 120 patients who underwent stent implantation for angiographically significant stenosis. Patients were divided into a soft plaque group (n = 50) and a nonsoft plaque group (n = 70). All patients underwent angiographic and intravascular ultrasound follow-up at 6 months. The baseline high-sensitivity C-reactive protein (hs-CRP) level was significantly higher in the soft plaque group. The follow-up minimal lumen diameter was significantly smaller in the soft plaque group. Soft plaque was detected in 73% of the ISR group but only 27% of the non-ISR group. Also, ISR was observed in 44% of the soft plaque group in contrast to only 11% of the nonsoft plaque group. The neointimal area at the minimal lumen cross-sectional area at follow-up was significantly larger in the soft plaque group (3.7 +/- 1.5 vs 1.9 +/- 1.5 mm2, p < 0.001). In conclusion, in patients with soft plaque, an elevated hs-CRP level was significantly associated with ISR (63% vs 15%, p < 0.001). By multivariate analysis, the combination of soft plaque and elevated hs-CRP was the most significant independent predictor of ISR.

Effect of lipid levels and lipid-lowering therapy on restenosis after coronary artery stenting

BACKGROUND

Recent experimental and clinical data suggest that lowering serum lipid levels with statins may prevent or delay the process of restenosis. The purpose of this trial is to determine whether lipid levels relate to restenosis and/or whether statin therapy can prevent or delay the process of restenosis after intracoronary stenting.

METHODS

One hundred thirty-six patients who underwent single coronary artery stenting from June 1995 to June 1997 in our institution were included in the study. All these patients were followed for at least 9 months (mean 392+/-148 days) for major adverse cardiac events (MACE). We defined as MACE the occurrence of death, myocardial infarction, or need for target lesion revascularization. From this cohort, 103 patients had at least one lipid parameter from the lipid profile evaluated within 2 months from the date of the procedure. Patients who had the stent because of an acute myocardial infarction were included in the study only if their lipid profile was evaluated before or at least 6 weeks after the event. Patients with triglyceride levels above 500 had both triglyceride and low-density lipoprotein cholesterol levels excluded from the statistical analysis. Patients were divided into two groups based on lipid levels: normal (Group I; n=31) and elevated (Group II; n=72). Patient outcomes were also analyzed by statin therapy use.

RESULTS

There was no significant difference in MACE rates between the two groups when outcomes were analyzed by lipid levels (22.6% versus 20.8% P=0.8). Furthermore, outcomes were analyzed by use of statin therapy (Group III, n=53, on statin versus Group IV, n=50, on no statin). There was also no difference in MACE rates between the two groups (20.8% versus 22%; P=0.8).

CONCLUSION

The process of restenosis has unique features that differentiate it from atherosclerosis. Although lipid-lowering therapy is crucial in delaying the process of atherosclerosis, its role in the prevention of restenosis is yet to be proven.

Elevated Plasma Active Matrix Metalloproteinase-9 Level Is Associated With Coronary Artery In-Stent Restenosis

Objective— This study aimed to determine whether the plasma levels of matrix metalloproteinase-9 (MMP-9) or tissue inhibitor of metalloproteinases-1 (TIMP-1) were altered in patients with a history of symptomatic in-stent restenosis (ISR).

Methods and Results— A group of 158 patients with a history of ISR were compared with 128 symptom-free patients. Plasma samples and a detailed risk factor history were collected. Plasma samples were analyzed for pro–MMP-9 and latent MMP-9 and active MMP-9, latent MMP-3, and TIMP-1. Several variables were associated with ISR, including index coronary disease extent and severity (number of diseased vessels and American College of Cardiology/American Heart Association lesion classification), number, diameter, and total length of stent(s) inserted, and plasma high-density lipoprotein cholesterol. Plasma active MMP-9 (odds ratio, 1.96; 95% CI, 1.43 to 2.69) showed independent risk association with ISR. Patients with multiple sites of ISR had significantly higher levels of active MMP-9 compared with patients with only a single ISR lesion or no ISR.

Conclusion— Plasma active MMP-9 levels may be a useful independent predictor of bare metal stent ISR.

Serum lipoprotein(a) level and clinical coronary stenosis progression in patients with myocardial infarction: re-revascularization rate is high in patients with high-Lp(a)

BACKGROUND

High serum lipoprotein(a) (Lp(a)) levels are associated with coronary artery disease.

METHODS AND RESULTS

The serum Lp(a) levels of 130 patients with acute myocardial infarction (AMI) who underwent direct percutaneous coronary intervention were investigated. On the basis of Lp(a) level at 1 month after the onset of AMI, the patients were classified into 2 groups (high-Lp(a) (> or =30 mg/dl) and low-Lp(a) (< 30 mg/dl)) for evaluation of the clinical coronary stenosis progression (CCSP) rate. CCSP is defined as either target lesion revascularization (TLR) or new lesion revascularization (NLR). The CCSP rate was significantly higher in the high-Lp(a) group than in the low-Lp(a) group (65.8% vs 29.3%, p<0.01). In patients who had coronary stents in the acute phase (n=79), the CCSP and NLR rates were significantly higher in the high-Lp(a) group than in the low-Lp(a) group (45.0% vs 20.3%, p<0.05; 35.0% vs 6.8%, p<0.01), but there was no significant difference in TLR rate between the 2 groups (10.0% vs 13.6%, p=0.858).

CONCLUSIONS

High serum Lp(a) level is a significant risk factor for CCSP, but does not influence restenosis after stenting.

C-Reactive protein, clinical outcome, and restenosis rates after implantation of different drug-eluting stents

Sirolimus-eluting stents (SESs), paclitaxel-eluting stents (PESs), and dexamethasone-eluting stents (DEXs) have anti-inflammatory properties; thus, the decreased in-segment restenosis rate observed with the use of these stents might be related to a weaker postprocedural inflammatory response. One hundred sixty consecutive patients with stable coronary artery disease who underwent successful single-vessel/lesion coronary artery stenting were prospectively studied. Thin-strut bare metal stents were deployed in 39 patients, SESs in 30, PESs in 61, and DEXs in 30. The 4 groups were similar with respect to demographic and angiographic variables and prevalence of risk factors. C-reactive protein (CRP) was measured at baseline and 24 and 48 hours after the procedure. Maximal increase in CRP was calculated as the increase in CRP at 48 hours/CRP compared with baseline. Angiographic follow-up was performed after 12.9 +/- 1.3 months or sooner, if needed, on the basis of clinical evidence. All patients presented a postprocedural increase in CRP that peaked at 48 hours (median 10.0 mg/L). Maximal CRP increase was similar across the 4 groups (medians 3.5 mg/L in the bare metal stent group, 3.6 mg/L in the SES group, 4.0 mg/L in the PES group, 3.5 mg/L in the DEX group, p = 0.45). Incidences of angiographic binary restenosis (>50% lumen diameter decrease) were 20.5% in the bare metal stent group, 3.3% in the SES group, 4.9% in the PES group, and 36.6% in the DEX group (p = 0.0004 for SES and PES groups vs bare metal stent and DEX groups). Postprocedural increase in CRP was significantly correlated with clinical and angiographic outcomes. In conclusion, the acute postprocedural systemic inflammatory response induced by drug-eluting stent implantation appears to be similar to that induced by bare metal stents. However, the restenosis rate is lower for SESs and PESs than for DEXs and bare metal stents. Thus, the decreased incidence of stent restenosis that was observed after SES and PES deployment is unlikely to be related to a decreased acute systemic inflammatory response, but rather to an increased local resistance to inflammatory mediators.

Persistent High Levels of Plasma Oxidized Low-Density Lipoprotein After Acute Myocardial Infarction Predict Stent Restenosis

OBJECTIVE

Recently, elevated levels of plasma oxidized low-density lipoprotein (LDL) have been shown to relate to plaque instability in human atherosclerotic lesions. We investigated prospectively patients admitted with acute myocardial infarction (AMI) who underwent primary coronary stenting to evaluate whether the 6-month outcome could be predicted by measuring plasma oxidized LDL (ox-LDL) levels at the time of hospital discharge.

METHODS AND RESULTS

Plasma ox-LDL levels were measured in 102 patients with AMI undergoing primary coronary stenting using a highly sensitive ELISA method. Measurements were taken on admission and at discharge, and the findings related to the clinical outcome. At 6-month follow-up, angiographic stent restenosis occurred in 25 (25%) of the 102 AMI patients. Plasma ox-LDL levels at discharge were significantly (P=0.0074) higher in the restenosis group than those in the no-restenosis group (1.03+/-0.65 versus 0.61+/-0.34 ng/5 microg LDL protein). Multiple regression analysis showed that only plasma ox-LDL levels at discharge were a statistically significant independent predictor for late lumen loss after stenting (beta=0.645; P<0.0001).

CONCLUSIONS

This prospective study demonstrates that persistence of an increased level of plasma ox-LDL at discharge is a strong independent predictor of stent restenosis at 6-month follow-up in AMI patients.

N-terminal probrain natriuretic peptide and C-reactive protein in stable coronary heart disease

PURPOSE

C-reactive protein (CRP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) provide prognostic information in patients with stable coronary heart disease. The aim of the study was to investigate whether combined use of NT-proBNP and CRP improves risk stratification in these patients.

METHODS

This cohort study included 989 patients with stable coronary heart disease who underwent coronary stenting. CRP and NT-proBNP were measured before angiography. The primary end point of the study was all-cause mortality. Using median values of NT-proBNP (279.9 ng/L) and CRP (1.2 mg/L), patients were divided into 4 groups: low NT-proBNP-low CRP group (305 patients with NT-proBNP<median and CRP<median); low NT-proBNP-high CRP group (190 patients with NT-proBNP<median and CRP> or =median; high NT-proBNP-low CRP group (237 patients with NT-proBNP> or =median and CRP<median); and high NT-proBNP-high CRP group (257 patients with NT-proBNP> or =median and CRP> or =median).

RESULTS

During a median follow-up of 3.6 years (interquartile range 3.3 to 4.5 years), there were 85 deaths: 6 deaths in the low NT-proBNP-low CRP group, 11 deaths in the low NT-proBNP-high CRP group, 20 deaths in the high NT-proBNP-low CRP group, and 48 deaths in the high NT-proBNP-high CRP group with Kaplan-Meier mortality estimates of 2.7%, 8.9%, 12.1% and 35.6%, respectively (P <.001). Cox proportional hazards model showed that combination NT-proBNP-CRP was the strongest independent correlate of mortality (hazard ratio [HR] 4.3, 95% confidence interval [CI], 2.0-9.3; P <.001 for high NT-proBNP-high CRP vs low NT-proBNP-low CRP).

CONCLUSION

Combined use of NT-proBNP and CRP improves long-term risk prediction of mortality in patients with stable coronary heart disease.

Impact of plasma aldosterone levels for prediction of in-stent restenosis

Aldosterone promotes vascular smooth muscle cell proliferation and endothelial dysfunction, suggesting the contribution to in-stent restenosis (ISR). This study evaluated any relation between plasma aldosterone levels and ISR 6 months after successful coronary stenting. We enrolled 156 consecutive patients with stable angina who underwent coronary bare metal stenting. Plasma aldosterone levels and other serum markers known to influence cardiovascular events were measured in all patients at baseline. Patients with restenosis were found to have significantly higher plasma aldosterone levels than their counterparts without restenosis (162 +/- 60 vs 122 +/- 60 pg/ml, p = 0.007). On logistic regression analysis, even after adjusting for clinical, angiographic, and other confounding variables, plasma aldosterone level per 10 pg/ml (odds ratio 1.34, 95% confidence interval 1.10 to 1.63, p = 0.006) proved to be the independent predictor of ISR. The area under the receiver-operating characteristic curve for plasma aldosterone level was 0.75, and the optimal cut-off value identified by receiver-operating characteristic analysis was 141.9 pg/ml, which had a predictive accuracy of 69%. In conclusion, the present findings indicate that plasma aldosterone levels at baseline are independent predictors of ISR and may constitute a potential therapeutic target.

Postinterventional homocysteine levels: Failure as a predictive biomarker of in-stent restenosis

OBJECTIVES

Purpose of our study was to determine if homocysteine plasma levels are related to the risk of in-stent restenosis after percutaneous coronary stent implantation in de novo lesions.

BACKGROUND

The putative role of homocysteine as a predictive cardiovascular biomarker of coronary artery disease is well established. The impact of homocysteine levels in the development of in-stent restenosis, however, is controversially discussed.

METHODS

A total of 177 patients with stable angina pectoris undergoing stent implantation in coronary de novo lesions were included. Laboratory determination comprised blood sample evaluation for homocysteine and other conventional risk factors before baseline coronary intervention and prior to six months control catheterization. Binary restenosis, late lumen loss, and late loss index after six months were assessed by quantitative coronary angiography. Endpoints included target lesion and target vessel failure, homocysteine levels as well as major adverse cardiac events.

RESULTS

There was a significant correlation between the length of the implanted stent (p<0.006), the percentage of stenosis (p<0.003) and the pre-interventional luminal diameter (p<0.0001) with late loss index. Linear regression analysis demonstrated no significant impact of the initial or six months homocysteine levels on angiographic restenosis, late lumen loss, or late loss index.

CONCLUSIONS

In contrast to homocysteine levels, luminal diameter, stent length and percentage of stenosis correlated with the appearance of restenosis. Taking our data into consideration, we hypothesise that homocysteine may not serve as a safe and independent biomarker of in-stent restenosis after a six months period following percutaneous coronary stenting.

Preinterventional peak monocyte count and in-stent intimal hyperplasia after coronary stent implantation in human coronary arteries

BACKGROUND

The mechanism of restenosis after stent implantation principally is neointimal hyperplasia. There is evidence that monocytes play a important role in in-stent restenosis (ISR) after stent implantation.

HYPOTHESIS

This study assessed the relationship between preinterventional peak monocyte count and neointimal growth after successful stent implantation.

METHODS

We performed coronary stent implantation in 85 patients (85 de novo lesions). Peripheral blood sample was obtained in all patients every 12 h before coronary angiography for measurement of peripheral monocytes. All patients received angiographic and intravascular ultrasound (IVUS) follow-up at 6 months after stenting.

RESULTS

The preinterventional circulating monocyte count was significantly higher in the ISR group than that in the group without ISR (654 +/- 62/vs. 461 +/- 222/mm3, p < 0.001) and was significantly higher in the reintervention group than that in the no-reintervention group (660 +/- 72/ vs. 470 +/- 216/mm3, p< 0.001). The incidence of ISR and repeat intervention associated with preinterventional monocyte count was highest among the patients in the highest tertile, who were at a 2.64-fold increased risk of ISR and 3.22-fold increased risk of repeat intervention compared with the patients in the lowest tertile. A significant positive correlation was found between preinterventional peak monocyte count and preinterventional plaque and media cross-sectional area and follow-up neointima area (r = 0.311, p = 0.007, r = 0.465, p < 0.001, respectively). The neointima area associated with preinterventional monocyte count was largest among the patients in the highest tertile, that is, 2-fold larger than that of the patients in the lowest tertile (p < 0.001) and 1.44-fold larger than that of the patients in the middle tertile (p = 0.001).

CONCLUSION

Our results suggest that circulating preinterventional monocytes play a principal role in the process of in-stent neointimal growth after successful stent implantation.