Inflammation, pravastatin, and the risk of coronary events after myocardial infarction in patients with average cholesterol levels. Cholesterol and Recurrent Events (CARE) Investigators

Effect of fluvastatin on long-term outcome after coronary revascularization with stent implantation

We assessed the impact of long-term fluvastatin treatment on adverse atherosclerotic cardiac events (cardiac death, myocardial infarction, and revascularization excluding repeat interventions due to restenosis in the first 6 months) in 847 patients (fluvastatin [n = 417] or placebo [n = 430]) with average cholesterol levels treated with stents in the Lescol Intervention Prevention Study (LIPS). During the 4-year follow-up period, fluvastatin significantly decreased total cholesterol and low-density lipoprotein cholesterol levels and decreased the risk of first adverse atherosclerotic cardiac events by 30% compared with placebo (95% confidence interval -49 to -3.4, p = 0.03).

Adverse outcome in aortic sclerosis is associated with coronary artery disease and inflammation

OBJECTIVES

The present study was designed to evaluate the relationship between the presence of aortic sclerosis, serologic markers of inflammation, and adverse cardiovascular outcomes.

BACKGROUND

Aortic sclerosis is associated with adverse cardiovascular outcomes. However, the mechanism by which such nonobstructive valve lesions impart excess cardiovascular risk has not been delineated.

METHOD

In 425 patients (mean age 68 +/- 15 years, 54% men) presenting to the emergency room with chest pain, we studied the relationship among aortic sclerosis, the presence and acuity of coronary artery disease, serologic markers of inflammation, and cardiovascular outcomes. Patients underwent echocardiography and serologic testing including C-reactive protein (CRP). Aortic valves were graded for the degree of sclerosis, and cardiovascular outcomes including cardiac death and nonfatal myocardial infarction (MI) were analyzed over one year.

RESULTS

Aortic sclerosis was identified in 203 patients (49%), whereas 212 (51%) had normal aortic valves. On univariate analysis at one year, patients with aortic sclerosis had a higher incidence of cardiovascular events (16.8% vs. 7.1%, p = 0.002) and worse event-free survival (normal valves = 93%, mild aortic sclerosis = 85%, and moderate to severe aortic sclerosis = 77%, p = 0.002). However, by multivariable analysis aortic sclerosis was not independently associated with adverse cardiovascular outcomes; the only independent predictors of cardiac death or MI at one year were coronary artery disease (hazard ratio [HR] 3.23, p = 0.003), MI at index admission (HR 2.77, p = 0.008), ascending tertiles of CRP (HR 2.2, p = 0.001), congestive heart failure (HR 2.15, p = 0.02) and age (HR 1.03, p = 0.04).

CONCLUSIONS

The increased incidence of adverse cardiovascular events in patients with aortic sclerosis is associated with coronary artery disease and inflammation, not a result of the effects of valvular heart disease per se.

Therapeutic Potential of Oral Antiproliferative Agents in the Prevention of Coronary Restenosis

The treatment of coronary artery disease has reached many milestones - from balloon angioplasty to drug-eluting stents. The last decade witnessed the revolution of bare metal stents with new designs, alloys and strut thicknesses. Yet restenosis, the aphorismic 'Achilles heel', remains to be conquered. The restenosis rates with balloon angioplasty alone are 30-40% and are reduced to 20-30% with stents. Although intravascular brachytherapy proved to be a durable and safely used technique to treat in-stent restenosis, clinical event rates were not reduced to single digits.Drug-eluting stents are showing positive results in this direction, but it is too early to predict their efficacy in various subsets of lesions. With the increased usage of these stents, there are reports of problems such as late stent malapposition, subacute and late thromboses, and aneurysm formations due to the vessel toxicity associated with this method of treatment. Furthermore, when multivessel stenting is considered, the cost of drug-eluting stents is a significant problem given the fact that these are no longer 'zero restenosis' devices. There is a definite need for a simple, safe and durable solution to restenosis. Oral agents are an alternative delivery strategy that can target multiple coronary lesions, which are targets for catheter-based revascularisation with any approved metal stent and with potentially lower cost. Although oral agents have been an interesting option to treat restenosis and several agents have been tested in trials since the 1980s, the results were disappointing. The development of devices such as intravascular ultrasound has led to a greater understanding of restenosis mechanisms, and the focus on pathophysiological mechanisms, which centred mainly on platelets, growth factors and lipids, has changed to inflammation, endothelium and smooth muscle cell proliferation.Accordingly, the targets of pharmaceutical agents have shifted from platelets to cell cycle inhibition, smooth muscle cell proliferation and migration, synthesis of extra cellular matrix, and inflammatory mediators. Initial encouraging results with oral drugs such as cilostazol, sirolimus (rapamycin) and thiazolidinediones indicate a definite place for this strategy to reduce restenosis. A desirable oral agent would be anti-inflammatory, inhibit smooth muscle cell migration and proliferation, promote endothelial growth, and be well tolerated and free from significant adverse effects. It may be useful to start with a high loading dose before stent implantation and then follow with a short-term lower maintenance dose. Future trials should be aimed at finding an ideal agent, effective loading dose, maintenance dose and optimum duration of therapy.

Statins in Hypertensive Patients

The recently published Lipid-Lowering Arm of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT-LLA) provides interesting evidence for the use of statins in hypertensive patients with average cholesterol concentrations and other cardiovascular risk factors. The clinical benefit of atorvastatin in these patients is probably explained by both lipid-dependent and lipid-independent effects of the drug. Many of these effects are related to inhibition of the synthesis of isoprenoid, which serves as lipid attachment for a variety of proteins implicated in intracellular signalling. These proteins have an important role in cell growth, actin cytoskeleton organisation, membrane trafficking, gene expression, cell proliferation/migration and programmed cell death. In this article we summarise the different effects of statins inrelation to the results observed in the ASCOT-LLA study.

Shear stress-dependent platelet function after LDL cholesterol apheresis

BACKGROUND

Platelets play a crucial role in the pathogenesis of acute coronary syndrome (ACS). Thrombus formation with subsequent arterial occlusion is a major determinant in ACS and stroke. Platelets also essentially contribute to the development and progression of atherosclerotic lesions. The aim of the present study was to investigate the effects lipid lowering by LDL apheresis on platelet function in patients with coronary artery disease.

METHODS

In six patients with angiographically proven coronary artery disease, venous blood samples were obtained before and after LDL cholesterol apheresis. Citrated whole blood (200 microl) was circulated in polystyrene wells at a shear rate of 1875 s(-1) for 2 min with a rotating teflon cone. Shear-stress dependent platelet adhesion was measured before and after apheresis.

RESULTS

After apheresis, there were significant reductions in LDL (-58%) and HDL (-17%) cholesterol, triglycerides (-43%), fibrinogen (-52%), lipoprotein (a) (-57%) and CRP (-57%) levels. LDL apheresis significantly reduced shear-stress dependent platelet adhesion. Bolus administration of heparin significantly prolonged activated clotting time, but had no significant effect on platelet adhesion or aggregates.

CONCLUSIONS

In patients with coronary artery disease, shear-stress dependent platelet adhesion is reduced by a single LDL apheresis. In addition to its cholesterol-lowering effect, LDL apheresis reduces circulating levels of fibrinogen and C-reactive protein.

Effect of coadministration of ezetimibe and simvastatin on high-sensitivity C-reactive protein

This study assessed the effect of ezetimibe coadministered with simvastatin on high-sensitivity C-reactive protein (hs-CRP) in patients with primary hypercholesterolemia. After dietary stabilization, a 2- to 12-week washout period, and a 4-week, single-blind, placebo lead-in period, patients with baseline low-density lipoprotein cholesterol > or =145 and < or =250 mg/dl and triglycerides < or =350 mg/dl were randomized to one of these daily treatments for 12 consecutive weeks: ezetimibe 10 mg; simvastatin monotherapy (10, 20, 40, or 80 mg); ezetimibe 10 mg plus simvastatin (10, 20, 40, or 80 mg); or placebo. The primary analysis was the change in hs-CRP for the pooled ezetimibe plus simvastatin versus simvastatin monotherapy groups. Ezetimibe plus simvastatin significantly reduced median hs-CRP levels compared with simvastatin monotherapy (-34.8% vs -18.2%, p<0.01), and incremental reductions were observed at each simvastatin dose level. Combination therapy-induced significant changes in individual lipid parameters did not explain the observed decreases in hs-CRP. Thus, ezetimibe coadministered with simvastatin resulted in significant incremental decreases in hs-CRP, possibly consistent with an additional anti-inflammatory effect compared with simvastatin monotherapy.

C reactive protein for risk stratification in acute coronary syndromes? Verdict: unproven

Although C reactive protein is intimately involved with the pathogenic mechanisms that drive acute coronary syndromes, there is no evidence that it is helpful for identifying patient groups who might benefit from particular treatment strategies

Comparison of rosuvastatin versus atorvastatin in patients with heterozygous familial hypercholesterolemia

Heterozygous familial hypercholesterolemia (HFH) is a common genetic disorder that confers a significantly increased risk of early coronary artery disease. This study compared atorvastatin and rosuvastatin in reducing low-density lipoprotein (LDL) cholesterol in HFH in a global, 18-week, weighted-randomization, double-blind, parallel-group, forced-titration study. Following a 6-week diet lead-in, 623 patients were randomized to 20 mg/day of atorvastatin (n = 187) or rosuvastatin (n = 436) with forced titration at 6-week intervals to 80 mg/day. The primary end point was percentage change in LDL cholesterol from baseline to week 18. At week 18, rosuvastatin therapy produced a significantly greater reduction in LDL cholesterol than atorvastatin (-57.9% vs -50.4%; p <0.001) and a significantly greater increase in high-density lipoprotein (HDL) cholesterol (12.4% vs 2.9%; p <0.001). Rosuvastatin also produced significantly greater reductions in apolipoprotein-B and all 4 major lipid ratios, as well as a significantly greater increases in apolipoprotein A-I (all p <0.001). More patients with HFH with coronary artery disease achieved the National Cholesterol Education Program Adult Treatment Panel III goal of LDL cholesterol <100 mg/dl (<2.6 mmol/L) on rosuvastatin 40 and 80 mg than atorvastatin 80 mg (17%, 24%, and 4.5%, respectively). High-sensitivity C-reactive protein median values were reduced by 33% to 34% in both the 80-mg rosuvastatin- and atorvastatin-treated groups. Both treatments were well tolerated. Thus, in HFH, rosuvastatin force titrated from 20 to 80 mg/day produced significantly greater reductions than atorvastatin 20 to 80 mg/day in LDL cholesterol and improvements in HDL cholesterol and other lipid parameters, and enabled more patients to achieve LDL cholesterol goals.

Increased levels of pregnancy-associated plasma protein-A in patients with hypercholesterolemia: the effect of atorvastatin treatment

BACKGROUND

Serum levels of pregnancy-associated plasma protein-A (PAPP-A) have recently been linked to plaque instability and are increased in acute coronary syndromes. The relation between PAPP-A levels and coronary risk factors, namely blood lipids, has not been studied to date. We have therefore investigated whether serum PAPP-A levels are increased in asymptomatic hypercholesterolemic subjects and whether PAPP-A levels are influenced by atorvastatin therapy.

METHODS

We examined 27 subjects with isolated hypercholesterolemia free of manifest vascular disease and 29 age-matched healthy control subjects. Patients were examined at baseline and after 10 weeks of atorvastatin treatment (20 mg/d).

RESULTS

In untreated hypercholesterolemic subjects, PAPP-A levels were significantly higher than in control subjects (8.02 +/- 1.86 mU/L vs 6.50 +/- 2.54 mU/L, P =.018). There was no correlation between PAPP-A levels and serum lipid levels. Atorvastatin treatment reduced total and LDL-cholesterol by 31% and 40%, respectively. Despite this profound lipid lowering, there was no significant change in the serum PAPP-A levels.

CONCLUSIONS

PAPP-A levels are elevated in hypercholesterolemic subjects without clinical signs of atherosclerosis. PAPP-A may therefore not only reflect plaque instability but also serve as a marker of total atherosclerotic burden in asymptomatic subjects with hyperlipidemia. However, PAPP-A levels are not influenced by atorvastatin treatment.

Macrophage cholesterol efflux and the active domains of serum amyloid A 2.1

Serum amyloid A 2.1 (SAA2.1) suppresses ACAT and stimulates cholesteryl ester hydrolase (CEH) activities in cholesterol-laden macrophages, and in the presence of a cholesterol transporter and an extracellular acceptor, there is a marked increase in the rate of cholesterol export in culture and in vivo. The stimulation of CEH activity by SAA2.1 is not affected by chloroquine, suggesting that it operates on neutral CEH rather than the lysosomal form. With liposomes containing individual peptides of SAA2.1, residues 1-20 inhibit ACAT activity, residues 74-103 stimulate CEH activity, and each of residues 1-20 and 74-103 promotes macrophage cholesterol efflux to HDL in culture media. In combination, these peptides exhibit a profound effect, so that 55-70% of cholesterol is exported to media HDL in 24 h. The effect is also demonstrable in vivo. [3H]cholesterol-laden macrophages injected intravenously into mice were allowed to establish themselves for 24 h. Thereafter, the mice received a single intravenous injection of liposomes containing intact SAA1.1, SAA2.1, peptides composed of SAA2.1 residues 1-20, 21-50, 51-80, 74-103, or SAA1.1 residues 1-20. Only liposomes containing intact SAA2.1 or its residues 1-20 or 74-103 promoted the efflux of cholesterol in vivo. A single injection of each of the active peptides is effective in promoting cholesterol efflux in vivo for at least 4 days.

Usefulness of lowering low-density lipoprotein cholesterol to <70 mg/dl and usefulness of C-reactive protein in patient selection

C-reactive protein levels may identify patients likely to benefit from lowering low-density lipoprotein (LDL) cholesterol to ultra-low levels. We find that above-average C-reactive protein with statin therapy predicts failure of carotid intima-media thickness regression in those with currently defined optimal LDL cholesterol (<100 mg/dl) but not if LDL cholesterol is <70 mg/dl.

Clinical use of high sensitivity C-reactive protein for the prediction of adverse cardiovascular events

PURPOSE OF REVIEW

Inflammation plays a central role in the initiation, progression, and destabilization of vascular atheroma. In an attempt to improve global cardiovascular risk assessment, considerable research has focused on markers of inflammation; in particular, high-sensitivity C-reactive protein, a pentraxin innate immune recognition molecule and classic acute-phase reactant.

RECENT FINDINGS

Multiple prospective studies now demonstrate that high-sensitivity C-reactive protein is a potent predictor of future cardiovascular events at all levels of low-density lipoprotein cholesterol, all levels of the Framingham Risk Score, and all levels of severity of the metabolic syndrome. Moreover, high-sensitivity C-reactive protein appears to be implicated in acute coronary syndromes and provides prognostic information on vascular risk among patients with renal dysfunction. In clinical settings, high-sensitivity C-reactive protein levels more than 3 mg/L are associated with the highest vascular risk.

SUMMARY

High-sensitivity C-reactive protein evaluation has recently been endorsed by the Centers for Disease Control and Prevention and by the American Heart Association to be used in conjunction with lipid evaluation as part of global risk prediction. Emerging evidence further suggests that high-sensitivity C-reactive protein can be used to target pharmacologic and lifestyle interventions designed to prevent first as well as recurrent cardiovascular events.

Inflammatory biomarkers of the patient with myocardial insufficiency

PURPOSE OF REVIEW

Inflammation plays a central role in the genesis of atherosclerosis and its complications. In this regard, plasma levels of several markers of inflammation have been shown to predict risk of future cardiovascular events, including cardiovascular death, myocardial infarction, and ischemic stroke. Furthermore, the predictive value of inflammatory markers is independent of traditional risk markers such as lipid levels, or cardiac troponin levels among those with acute coronary syndromes.

RECENT FINDINGS

Indeed, recent data suggest that among more than 27,000 apparently healthy women, the predictive value of C-reactive protein, the most extensively studied marker of vascular inflammation, was at least as good as that of low-density lipoprotein cholesterol. In addition, hypothesis-generating data suggest that the benefits of proven interventions such as statin therapy and glycoprotein IIb/IIIa receptor blockade may be most effective among those with elevated markers of inflammation.

SUMMARY

Combining our evolving understanding of the vascular biology of atherosclerosis with clinical studies of inflammatory markers and mediators may help refine our diagnostic and therapeutic armamentarium for cardiovascular disease.

Increased C-reactive protein concentrations in never-treated hypertension

OBJECTIVE

To test whether the plasma concentration of C-reactive protein (CRP), a sensitive marker of systemic inflammation, is increased in patients with newly diagnosed, never-treated hypertension and whether blood pressure and its pulsatile component, pulse pressure, are correlated with plasma CRP concentration independently of a consistent number of cardiovascular risk factors.

DESIGN

Cross-sectional study in a hospital outpatient hypertension clinic.

METHODS

A total of 135 newly diagnosed, never-treated patients with hypertension and 40 healthy matched non-hypertensive controls underwent office and 24-h blood pressure measurement and blood sampling for determination of plasma CRP and serum lipid concentrations.

RESULTS

Plasma CRP concentration was greater in hypertensive individuals (1.85 mg/l, interquartile range 0.74-3.64) than in control individuals (1.01 mg/l, interquartile range 0.67-1.88; P = 0.02). In the entire population, CRP had a significant direct association with office systolic blood pressure and pulse pressure, but not with diastolic blood pressure. Among hypertensive patients, plasma CRP was related to 24-h systolic blood pressure (r = 0.28, P < 0.01) and pulse pressure (r = 0.32, P < 0.01), but not to diastolic blood pressure (r = 0.12, P > 0.2). CRP was also directly associated with body mass index (r = 0.25, P < 0.01), serum low-density lipoprotein cholesterol (r = 0.21, P = 0.03) and serum triglycerides (r = 0.21, P = 0.03). In the multivariate analysis, systolic blood pressure and pulse pressure, but not diastolic blood pressure, were significant predictors of plasma CRP concentration when a consistent number of cardiovascular risk factors was controlled for simultaneously.

CONCLUSIONS

Systolic blood pressure and pulse pressure, but not diastolic blood pressure, are predictors of plasma C-reactive protein concentrations in patients with newly diagnosed, never-treated hypertension, irrespective of the potential proinflammatory action of traditional cardiovascular risk factors.

Influence of aspirin on inflammatory markers in patients after acute myocardial infarction

The aim of this study was to assess the influence of aspirin on selected inflammatory markers in patients recovering from acute myocardial infarction (AMI). Patients participating in the Warfarin Aspirin Re-Infarction Study-II were randomized to either aspirin 160 mg/day or aspirin 75 mg/day + warfarin, or warfarin alone after AMI. After AMI, aspirin 160 mg/day was associated with significantly lower levels of high-sensitivity C-reactive protein and tumor necrosis factor-alpha than warfarin alone over 4 years. However, the same levels were not predictors for clinical end points.

Dietary lipids in the aetiology of Alzheimer's disease: implications for therapy

Amyloid plaques and neurofibrillary tangles are the neuropathological hallmarks of Alzheimer's disease (AD), but no conclusive evidence has emerged showing that these hallmarks are the cause and not a product of the disease. Many studies have implicated oxidation and inflammation in the AD process, and there is growing evidence that abnormalities of lipid metabolism also play a role. Using epidemiology to elucidate risk factors and histological changes to suggest possible mechanisms, the hypothesis is advanced that dietary lipids are the principal risk factor for the development of late-onset sporadic AD. The degree of saturation of fatty acids and the position of the first double bond in essential fatty acids are the most critical factors determining the effect of dietary fats on the risk of AD, with unsaturated fats and n-3 double bonds conferring protection and an overabundance of saturated fats or n-6 double bonds increasing the risk. The interaction of dietary lipids and apolipoprotein E isoforms may determine the risk and rate of sustained autoperoxidation within cellular membranes and the efficacy of membrane repair. Interventions involving dietary lipids and lipid metabolism show great promise in slowing or possibly averting the development of AD, including dietary changes, cholesterol-modifying agents and antioxidants.

Diabetes and Vascular Disease

The incidence of diabetes is on the rise; most of this increase is accounted for by type 2 diabetes and is secondary to the growing prevalence of obesity. Most of the late complications of both type 1 and type 2 diabetes are secondary to microvascular and macrovascular complications. Microvascular complications include retinopathy, neuropathy, and nephropathy. Nephropathy is strongly linked to the complications of macrovascular disease, which include cardiovascular, cerebrovascular, and peripheral vascular disease. Hence, once microalbuminuria (an early marker of nephropathy) is present, the patient is at a greater risk of cardiovascular disease and other microvascular complications, including retinopathy. A number of cellular mechanisms are altered secondary to hyperglycemia, and recently, a common pathway linking these mechanisms has been proposed, ultimately leading to oxidative damage and thus end-organ or tissue damage. Due to the increased risk of vascular complications, many diabetic patients undergo surgical procedures, including revascularization and bypass. Recent studies have highlighted the importance of strict glycemic control during the perioperative and postoperative period, even in the nondiabetic patient. The results of these studies have shown a decrease in morbidity, mortality, and hospital stay with strict glycemic control. Glycemic control has been directly linked to decreased microvascular complications. Macrovascular disease, however, has not been clearly linked to glucose levels alone, and although it certainly plays a role, other components of the metabolic syndrome, including blood pressure and lipid status, are equally important.

Thrombin, inflammation, and cardiovascular disease: an epidemiologic perspective

The exploration of coagulation led to identifying inflammation as a major factor in arterial disease throughout life. "Integrative molecular physiology" reflects our emerging understanding of how coagulation and inflammation integrate with one another, in both normal physiology and in pathophysiology. Our own responses to environmental challenge provide much of the damage that cumulatively results in chronic cardiovascular disease. Only by intervening in exquisitely precise ways can we hope to effectively and safely modify the course of lifelong chronic diseases, such as atherosclerosis.

Inflammatory and thrombotic mechanisms in coronary atherosclerosis

Many molecular and cellular mechanisms link inflammation and haemostatic mechanisms. Inflammation, and perhaps chronic infection, may play important roles in the initiation and progression of atherosclerosis. Atherosclerotic lesions are heavily infiltrated by cellular components associated with inflammation (macrophages and T lymphocytes), and acute plaque rupture is also associated with inflammatory components. Several markers of systemic inflammation may predict future cardiovascular events in apparently healthy subjects as well as in patients with chronic and acute syndromes. There may thus be therapeutic potential in modifying the atherosclerotic, vasomotor, and thrombotic components of ischaemic heart disease.

An elevated value of C-reactive protein is the only predictive factor of restenosis after percutaneous coronary intervention

BACKGROUND

The current techniques for percutaneous coronary interventions (PCI) remain limited by restenosis. Recent studies have provided evidence of inflammation playing a role in the pathogenesis of cardiovascular disease.

METHODS

Whether inflammatory markers are predictors of subsequent restenosis were prospectively tested in 272 consecutive patients with angiographically proven coronary artery disease. Patients having undergone PCI at Chonnam National University Hospital, between Sept. 1999 and Mar. 2001, were divided into two groups according to the occurrence of restenosis on a follow-up coronary angiogram: Group I were patients with restenosis (n = 99, 59.5 +/- 10.8 years, M:F = 77:22) and Group II were those without restenosis (n = 173, 58.8 +/- 10.2 years, M:F = 131:42). The IgG seropositivity, cytomegalovirus (CMV) titers, C. pneumoniae. H. pylori and levels of C-reactive protein (CRP) were compared between the two groups.

RESULTS

There were no statistical differences in the seropositivity of the CMV IgG C. pneumoniae IgG and H. pylori IgG between the two groups (Groups I vs. II: 100 vs. 100%, 24.7 vs. 25.7% and 62.2 vs. 63.7%, respectively). Of the angiographic parameters, a low Thrombolysis in Myocardial Infarction (TIMI) flow (TIMI 0 or 1) was more common in Group I than Group II (p = 0.038). The patients with an elevated CRP (> 0.5 mg/dL) were more common in Group I than Group II (57.6 vs. 36.4%, p = 0.001), with the CRP values being higher in Group I than Group II (3.3 +/- 5.8 vs. 1.3 +/- 2.6 mg/dL, p = 0.001). According to a multiple logistic regression analysis, the CRP was the only predictor of restenosis, with an odds ratio of 2.1169 (95% C.I. 1.2062-3.7154, p = 0.009).

CONCLUSION

The CRP value is the most important predictor of restenosis after PCI.

C-reactive protein concentration and concentrations of blood vitamins, carotenoids, and selenium among United States adults

OBJECTIVE

To examine the relationships between circulating concentrations of C-reactive protein and concentrations of retinol, retinyl esters, vitamin C, vitamin E, carotenoids, and selenium.

DESIGN

Cross-sectional study using National Health and Nutrition Examination Survey III (1988-1994) data.

SETTING

United States population.

SUBJECTS

Up to 14 519 US noninstitutionalized civilian men and women aged > or=20 y.

RESULTS

C-reactive protein concentration (dichotomized at the sex-specific 85th percentile) was inversely and significantly associated with concentrations of retinol, retinyl esters, vitamin C, alpha-carotene, beta-carotene, cryptoxanthin, lutein/zeaxanthin, lycopene, and selenium after adjustment for age, sex, race or ethnicity, education, cotinine concentration, body mass index, leisure-time physical activity, and aspirin use.

CONCLUSIONS

These results suggest that the inflammatory process, through the production of reactive oxygen species, may deplete stores of antioxidants. Whether increased consumption of foods rich in antioxidants or supplementation with antioxidants can provide health benefits to people characterized by elevated C-reactive protein concentrations may be worthy of further study.

High-sensitivity C-reactive protein and cardiovascular risk: rationale for screening and primary prevention

Inflammation is a major factor in atherothrombotic disease. Levels of high-sensitivity C-reactive protein (hs-CRP), a marker of systemic inflammation and a mediator of atherothrombotic disease, have been shown to correlate with cardiovascular disease risk. Recent findings in 27,939 healthy women in the Women's Health Study indicate that hs-CRP (1) is a stronger predictor of risk than low-density lipoprotein (LDL) cholesterol, (2) predicts elevated risk in subjects without overt hyperlipidemia, and (3) adds prognostic information to risk scoring and LDL cholesterol categories. Other data from this cohort show that hs-CRP level adds prognostic information to the diagnosis of the metabolic syndrome. Taken together with other data in men on the association of hs-CRP with vascular risk, a strong argument is provided for screening in the primary prevention population. With regard to potential treatment, statins have been found to reduce hs-CRP levels, and data from statin treatment trials raise the possibility that subjects with elevated hs-CRP levels may derive greater benefit from treatment than do patients without elevated hs-CRP. The Justification for the Use of Statins in Primary Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) trial is planned to examine the effects of rosuvastatin treatment in preventing cardiovascular events in 15,000 healthy subjects with elevated hs-CRP levels in the absence of overt hyperlipidemia.

C-reactive protein and coronary events following percutaneous coronary angioplasty

PURPOSE

We investigated the associations between baseline C-reactive protein levels in patients undergoing percutaneous coronary angioplasty and death, nonfatal myocardial infarction, and repeat revascularization during 14 months of follow-up.

METHODS

In a single-center, prospective, cohort study, plasma levels of C-reactive protein were measured in 1458 consecutive patients undergoing elective or urgent coronary angioplasty. Patients were followed at 12 to 14 months for the occurrence of death, nonfatal myocardial infarction, and repeat revascularization.

RESULTS

The incidence of death or myocardial infarction was 6.1% (44/716) in patients with an increased C-reactive protein level (>3 mg/L) and 1.5% (11/742) in patients with a normal level (relative risk [RR] = 4.4; 95% confidence interval [CI]: 2.2 to 8.5; P <0.0001). In a multivariate logistic regression model, an increased C-reactive protein level was an independent predictor of death or nonfatal myocardial infarction (RR = 3.6; 95% CI: 1.8 to 7.2; P =0.0001). The incidence of repeat revascularization was similar in patients with or without an increased C-reactive protein level (23% [168/716] vs. 22% [163/742], P = 0.54). Statin therapy at the time of the procedure was associated with a lower mean (+/- SD) C-reactive protein level (5.8 +/- 9.7 mg/L vs. 7.2 +/- 12.1 mg/L, P =0.02), but was not associated with the risk of death, nonfatal myocardial infarction, and repeat revascularization during follow-up.

CONCLUSION

An increased C-reactive protein level is an independent prognostic indicator for the occurrence of death or nonfatal myocardial infarction following coronary angioplasty, but is not associated with the need for repeat revascularization.

Preanalytic and analytic sources of variations in C-reactive protein measurement: implications for cardiovascular disease risk assessment

BACKGROUND

C-reactive protein (CRP) is a widely recognized indicator of inflammation and is known to play an important role in atherogenesis. Recent prospective studies have demonstrated that increased CRP concentrations within the reference interval are a strong predictor of myocardial infarction, stroke, sudden cardiac death, and peripheral vascular disease in apparently healthy adults. On the basis of available evidence, the American Heart Association and the CDC have issued guidelines for the utility of CRP in the primary prevention of coronary heart disease and in patients with stable coronary disease or acute coronary syndromes. Nevertheless, there remains considerable work to optimize the utility of this marker for risk assessment.

ISSUES

Most traditional CRP tests designed to monitor acute and chronic inflammation have inadequate sensitivity for risk stratification of coronary disease. Thus, manufacturers have had to develop tests with higher sensitivity. Because an individual's CRP concentration will be interpreted according to fixed cut-points, issues related to the preanalytic and analytic components of CRP measurement must be considered and standardized where possible to avoid potential misclassification of cardiovascular risk.

CONCLUSIONS

Efforts to define performance criteria for high-sensitivity CRP applications coupled with growing awareness of the physiologic aspects of CRP most likely will lead to refinements in standardization, improved performance in quality-assessment schemes, and enhanced risk prediction.

Usefulness of aortic valve calcium scores by electron beam computed tomography as a marker for aortic stenosis

This study was undertaken to determine whether aortic valve calcium (AVC) scores measured by electron beam tomography can identify patients with echocardiographically defined aortic stenosis. Electron beam tomography is increasingly being used to detect coronary artery calcium. AVC can also be measured on electron beam tomographic (EBT) scans obtained to screen for coronary calcium. Whether EBT AVC scores correlate with the presence of aortic stenosis, as assessed by echocardiography, is unknown. Results of this study suggest that AVC scores should be calculated routinely for coronary calcium screening EBT scans, and that patients with Agatston AVC scores above a certain level (e.g., >150) should be referred for echocardiography.

The prognostic value of high-sensitive C-reactive protein and cardiac troponin T in young and middle-aged patients with chest pain without ECG changes

BACKGROUND: There is growing evidence of the prognostic importance of inflammatory markers in angina pectoris. However, the independent value of high-sensitive C-reactive protein (hsCRP), cardiac troponin T (cTnT), or their combination has not been established in young patients with angina pectoris without ECG changes. Therefore, we assessed the 6-month prognostic values of serum hsCRP and cTnT in young and middle-aged patients who were admitted to the hospital with chest pain but without ECG changes. METHODS: Forty young or middle-aged patients (45+/-10 years old; two females) were included in the study. All had chest pain for the first time without ST-T changes or any other ECG changes and with normal CPK-MB levels. Blood was drawn on admission, separated, and serum was frozen at -80 degrees C for 1 year until thawed and studied as one batch in order to measure hsCRP and cTnT levels. A clinical follow-up was done for 6 months. RESULTS: Our findings showed that the strongest independent marker of an adverse outcome was the hsCRP level on admission (sensitivity 66.7%; specificity 94.1%); cTnT level added a little to the specificity (97.1%), but did not add to the sensitivity that was found by hsCRP level. CONCLUSIONS: hsCRP level on admission could be an independent prognostic marker in young and middle-aged patients with angina pectoris without ECG changes and without CPK-MB elevation.

C-reactive protein, inflammation, and coronary risk

Advancements in understanding of the pathobiology of atherothrombosis have implicated inflammation as a central contributor to the progression of atherosclerotic vascular disease. Epidemiologic data demonstrate an association between the inflammatory marker hs-CRP and risk for future cardiovascular morbidity and mortality among those at high risk or with documented vascular disease. Moreover, a series of prospective studies provides consistent data documenting that mild elevation of baseline levels of hs-CRP among apparently healthy individuals is associated with higher long-term risk for future cardiovascular events. Among men and women, this predictive capacity of hs-CRP is independent of traditional cardiovascular risk factors and offers a prognostic advantage over measurement of lipids alone. Further, observations from the PHS and CARE trial suggest that the increased risk associated with systemic inflammation may be modified with certain preventive therapies and that inflammatory markers such as hs-CRP may help to identify those who would benefit most from these pharmacologic interventions. Given that high-throughput assays for inflammatory markers, including hs-CRP, are likely to become available for clinical use, carefully designed studies are needed to evaluate the clinical efficacy of hs-CRP as a new marker to stratify cardiovascular risk. Further, prospective, randomized trials are important to test directly the value of inflammatory markers in targeting specific preventive therapies. Finally, it is still undetermined as to whether elevation of these inflammatory markers reflects the degree of underlying atherosclerosis or plaque vulnerability or rather results from some other environmental or infectious stimulus or even has direct effects on platelet aggregation or coagulation [1]. Ongoing and future investigation will clarify the specific pathophysiologic relationships through which these markers correlate with adverse prognosis.

Soluble intercellular adhesion molecule-1 and interleukin-6 levels reflect endothelial dysfunction in patients with primary hypercholesterolaemia treated with atorvastatin

Adhesion molecules and cytokines are involved in the pathogenesis of intimal injury in atherosclerosis but their relationship with endothelial function remains unclear. The objectives of this study were to examine the effects of atorvastatin on soluble adhesion molecules, interleukin-6 (IL-6) and brachial artery endothelial-dependent flow mediated dilatation (FMD) in patients with familial (FH) and non-familial hypercholesterolaemia (NFH). A total of 74 patients (27 FH and 47 NFH) were recruited. Fasting lipid profiles, soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular-cellular adhesion molecule-1 (sVCAM-1), E-selectin, IL-6 and FMD were measured at baseline, 2 weeks, 3 and 9 months post-atorvastatin treatment (FH--80 mg/day, NFH--10 mg/day). In both groups, compared to baseline, sICAM-1 levels were significantly reduced at 2 weeks, further reduced at 3 months and maintained at 9 months (P<0.0001). The IL-6 levels were significantly reduced at 3 months and 9 months compared to baseline for FH (P<0.005) and NFH (P<0.0001). In both groups, the FMD at 2 weeks was higher than baseline (P<0.005), with progressive improvement up to 9 months. FMD was negatively correlated with sICAM-1 and IL-6. In conclusion, both low and high doses of atorvastatin lead to early progressive improvement in endothelial function in patients with primary hypercholesterolaemia. sICAM-1 and IL-6 levels reflect endothelial dysfunction in these patients.

Anti-inflammatory effect of atorvastatin (80 mg) in unstable angina pectoris and non-Q-wave acute myocardial infarction

In this randomized trial, C-reactive protein increased during the first 5 days of an acute coronary syndrome in patients treated with placebo, but this phenomenon was not observed in those randomized to atorvastatin 80 mg/day. This suggests that short-term statin therapy inhibits inflammation in patients with non-ST-elevation acute coronary syndromes.

The incidence and risk factors of cholesterol embolization syndrome, a complication of cardiac catheterization: a prospective study

BACKGROUND

Cholesterol embolization syndrome is a systemic disease caused by distal showering of cholesterol crystals after angiography, major vessel surgery, or thrombolysis.

METHODS

We prospectively evaluated a total of 1,786 consecutive patients 40 years of age and older, who underwent left-heart catheterization at 11 participating hospitals. The diagnosis of CES was made when patients had peripheral cutaneous involvement (livedo reticularis, blue toe syndrome, and digital gangrene) or renal dysfunction.

RESULTS

Twenty-five patients (1.4%) were diagnosed as having CES. Twelve patients (48%) had cutaneous signs, and 16 patients (64%) had renal insufficiency. Eosinophil counts were significantly higher in CES patients than in non-CES patients before and after cardiac catheterization. The in-hospital mortality rate was 16.0% (4 patients), which was significantly higher than that without CES (0.5%, p < 0.01). All four patients with CES who died after cardiac catheterization had progressive renal dysfunction. The incidence of CES increased in patients with atherosclerotic disease, hypertension, a history of smoking, and the elevation of baseline plasma C-reactive protein (CRP) by univariate analysis. The femoral approach did not increase the incidence, suggesting a possibility that the ascending aorta may be a potential embolic source. As an independent predictor of CES, multivariate regression analysis identified only the elevation of pre-procedural CRP levels (odds ratio 4.6, P = 0.01).

CONCLUSIONS

Cholesterol embolization syndrome is a relatively rare but serious complication after cardiac catheterization. Elevated plasma levels of pre-procedural CRP are associated with subsequent CES in patients who undergo vascular procedures.

Utility of inflammatory markers in the management of coronary artery disease

Certain markers of systemic inflammation are powerful predictors of cardiovascular events. Fibrinogen, C-reactive protein (CRP), and cytokines are among the inflammatory markers associated with various cardiovascular end points. Fibrinogen and CRP both have been associated with coronary artery disease (CAD) mortality in patients with stable angina. High-sensitivity CRP (hs-CRP) and fibrinogen also have prognostic value in patients with unstable angina. In addition to prognostic implications, several cardiovascular risk factors (eg, smoking, obesity, diabetes) are associated with high levels of fibrinogen and hs-CRP. Benefits from aspirin are more likely in patients whose hs-CRP levels are very high. Some fibrates decrease fibrinogen levels and hs-CRP. Statin therapy either reduces the CAD risk associated with system inflammation or lowers circulating levels of hs-CRP.

A practical approach to risk assessment to prevent coronary artery disease and its complications

The recent focus on emerging cardiovascular risk factors, such as C-reactive protein, homocysteine, and small, dense low-density lipoprotein (LDL), may give the false impression that the current approach to the assessment of cardiovascular disease risk fails to identify a large section of the high-risk population. On the contrary, the new guidelines of the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) propose classifying an enormous number of individuals, including people with any form of atherosclerotic disease, diabetes, and a combination of major risk factors, into the category of high risk (>20% likelihood of a major coronary event or stroke in 10 years). Considering the widespread prevalence of the metabolic syndrome-a high-risk condition characterized by mild hypertension, mild dyslipidemia, hyperglycemia, and visceral obesity-we may be faced with the challenge of implementing aggressive risk reduction therapies in as much as 30% of the adult US population. From the point of view of risk assessment, a practical approach is to follow the NCEP guidelines (ie, place patients with diabetes and those with atherosclerotic complications in the highest risk category), apply the Framingham calculation to determine risk in people with common risk factors, and initiate early intervention in people who have familial hypercholesterolemia (LDL cholesterol >200 mg/dL) or a family history of early cardiovascular disease. The emerging risk factors may be useful for further stratifying risk in individuals with intermediate risk and the presence of risk factors not included in the Framingham calculation.

The effect of statin therapy on ventricular late potentials in acute myocardial infarction

AIMS

To determine whether early statin therapy in acute myocardial infarction has any effect on ventricular late potentials which are considered as a noninvasive tool for evaluation of arrhythmogenic substrate.

METHODS AND RESULTS

Study population consisted of prospectively enrolled 72 patients presenting with acute myocardial infarction (<6 h). Thirty-four of the patients were randomized to pravastatin (40 mg/day) on admission irrespective of lipid levels. All patients received thrombolytic therapy. Signal-averaged ECG recordings were obtained serially prior to thrombolytic therapy, 48 h after and 10 days later. Late potentials were defined as positive if signal-averaged ECG met at least two of Gomes criteria: filtered total QRS duration >114 ms, root mean square voltage of the last 40 ms of the QRS <20 mV, or the duration of the terminal low (<40 mV) amplitude signals >38 ms. Changes observed in signal-averaged ECG recordings after thrombolysis were evaluated statistically with regard to statin usage. There were no significant differences between the clinical characteristics of the two randomized groups. There was a significant decrease in the rates of late potentials between the first and third signal-averaged ECG recordings after thrombolytic therapy in pravastatin group. Pravastatin group also had lower incidence of ventricular arrhythmias compared with control group (26 vs. 63%, P=0.021). The in-hospital cardiovascular event rates were also lower in statin group.

CONCLUSION

Early use of pravastatin reduces the incidence of late potentials following thrombolytic therapy in acute myocardial infarction. Statin therapy also seems to be reducing the incidence of in-hospital ventricular arrhythmias. These beneficial effects of statins might be explained through prevention of new myocardial ischemic episodes due to early plaque stabilization or regulation of endothelial and platelet functions.

High Sensitivity C-Reactive Protein in Clinical Practice

As a growing number of patients with low low-density lipoprotein cholesterol levels are diagnosed with atherosclerosis, research has shifted toward markers of inflammation in an attempt to improve global cardiovascular risk prediction. These markers include cytokines, cell adhesion molecules, and acute phase reactants like high sensitivity C-reactive protein, an innate immune response protein. When measured with new high-sensitivity assays, levels of high sensitivity C-reactive protein have proven to predict future cardiovascular risk at all levels of low-density lipoprotein cholesterol, at all levels of the Framingham Risk Score, and at all levels of the metabolic syndrome. Among apparently healthy men and women, levels of high sensitivity C-reactive protein of <1, 1-3, and >3 mg/L distinguish between those at low, moderate, and high risk for future cardiovascular disease, respectively. In clinical practice, high sensitivity C-reactive protein should be used along with lipid evaluation as part of global risk assessment. Improved knowledge of cardiovascular risk should lead to improved compliance with both lifestyle and pharmacologic interventions designed to prevent future cardiovascular events.

C-reactive protein: a novel marker of cardiovascular risk

Patients without traditional cardiovascular risk factors continue to suffer from cardiovascular events, which has prompted a search for novel markers to better assess cardiovascular risk. Inflammatory biomarkers have surfaced as prime candidates, given the integral role of inflammation in atherosclerosis. C-reactive protein (CRP) measurements in particular have emerged as powerful predictors of cardiovascular risk in a broad spectrum of patient populations. Newer high sensitivity CRP assays now in use are standardized and reproducible, and can detect variations in CRP below the limit of standard assays. In primary prevention populations, studies have shown up to a 2-4-fold increased risk of cardiovascular events in healthy patients with elevated CRP levels. In this population, models incorporating CRP and lipid parameters appear to predict risk significantly better than lipids alone. In patients with established cardiovascular disease and in patients undergoing percutaneous coronary interventions, CRP levels may help predict short- and long-term prognosis, identifying subgroups of patients at increased risk of recurrent events. CRP levels may also prove useful in targeting therapy for primary and secondary prevention, by identifying patients who would most benefit from medications such as statins and aspirin. This review presents an overview of the data regarding CRP measurement for cardiovascular risk assessment.

C-reactive protein activates complement in infarcted human myocardium

Circulating levels of C-reactive protein (CRP) constitute a cardiovascular risk marker. Immunohistochemical studies have revealed co-localization of CRP and activated complement in human infarcted myocardium suggesting CRP to enhance inflammation in ischemic myocardium by inducing local complement activation. The aim was to establish whether CRP activates complement in infarcted human myocardium and to assess the relationship between this activation and the duration of infarction. Myocardial tissue samples from 56 patients that had died from acute myocardial infarction were evaluated. Specimens were taken from infarcted as well as noninfarcted sites of the heart. CRP-mediated complement activation was assessed by immunohistochemistry and by measuring levels of complement, CRP, and CRP-complement complexes, specific markers for CRP-mediated activation, in homogenates of the heart. Infarctions of 12 hours to 5 days had significantly more extensive depositions of complement and CRP and contained significantly more CRP, activated complement, and CRP-complement complexes than infarctions that were less than 12 hours old. Levels of CRP complexes correlated significantly with CRP and complement concentrations in the infarctions, as well as with the extent of complement and CRP depositions as measured via immunohistochemistry. Specific activation products of CRP-mediated activation of complement are increased in infarcts of more than 12 hours in duration and correlate with the extent of complement depositions. Hence, CRP seems to enhance local inflammatory reactions ensuing in human myocardial infarcts of more than 12 hours duration.

Relationship between effects of statins, aspirin and angiotensin II modulators on high-sensitive C-reactive protein levels

Statins, aspirin and angiotensin II modulators (A II-M: angiotensin-converting enzyme (ACE) inhibitors and angiotensin II type I receptor blockades) may have an anti-inflammatory effect, but the relationship between the effects of statins, aspirin and A II-M on high-sensitive C-reactive protein (hs-CRP) levels remains to be determined. We examined serum hs-CRP levels in consecutive patients with stable ischemic heart disease (IHD) (n=1231; 65+/-9 years; male/female, 927/304) and without IHD (n=226; 64+/-9 years; male/female, 117/109). Blood samples were collected on the day of catheterization. The hs-CRP levels were significantly higher in the IHD than in the non-IHD patients (0.32+/-0.52 vs. 0.24+/-0.29 mg/dl, P<0.05). Treatment with statins was associated with significantly lower hs-CRP levels in both groups (non-IHD, 0.17+/-0.14 vs. 0.26+/-0.31 mg/dl; IHD, 0.27+/-0.34 vs. 0.35+/-0.59 mg/dl; both P<0.05). hs-CRP levels were significantly lower only in IHD patients treated with A II-M than in those not treated with A II-M (0.28+/-0.34 vs. 0.34+/-0.58 mg/dl, P<0.05). Aspirin did not have any effect on the hs-CRP level in either group. The hs-CRP levels were significantly lower in IHD patients treated with statins and/or A II-M than those treated with neither statins nor A II-M (statin+/A II-M+, 0.28+/-0.29 mg/dl; statin+/A II-M-, 0.26+/-0.36 mg/dl; statin-/A II-M+, 0.28+/-0.37 mg/dl; statin-/A II-M-, 0.38+/-0.66 mg/dl; P<0.01). These results indicate that statins and A II-M, but not aspirin, in commonly used doses have an anti-inflammatory action as assessed by measurement of CRP levels in IHD patients.

Oral health status, C-reactive protein and mortality--a 10 year follow-up study

BACKGROUND

Epidemiological studies have reported a strong association between C-reactive protein (CRP) and cardiovascular diseases (CVD). Elevated CRP levels have been observed both in dentate individuals with chronic dental infections like periodontal disease and in those edentulous. The mechanisms behind these observations, especially the reasons for the elevation of CRP in the edentulous, are poorly understood. The comparative data on the importance of these inflammatory conditions in the oral cavity as causes of elevated CRP levels and CVD risk factors are also limited.

OBJECTIVE

To determine if edentulism is associated with increased levels of CRP and investigate the possible mechanism for this association; and to study the influence of periodontal disease and edentulism on 10-year mortality.

SUBJECTS

Of the 364 subjects aged 76, 81, and 86 years in 1990, 196 were dentate and 168 edentulous. By December 1999, 179 had died, almost half (n = 87) of them due to cardiovascular disease.

RESULTS

Significantly more of the edentulous subjects had elevated (> or = 3 mg/L) CRP levels as compared to those with at least 20 teeth (p < 0.01). They also had high salivary microbial counts (p < 0.05), and more mucosal lesions (p < 0.0001) than those with at least 20 teeth. In multivariate analysis, high microbial counts (OR 2.3, CI 1.06-5.05) and mucosal lesions (OR 2.18, CI 1.03-4.61) were significantly associated with elevated CRP levels. The risk for all-cause mortality was non-significantly elevated among the edentulous (RR 1.48, CI 0.95-2.31) and dentate with periodontal disease (RR 1.58, CI 0.96-2.61). CVD mortality was significantly higher among the dentate with periodontal disease (RR 1.97, CI 1.01-3.85) when compared with dentate without periodontal disease.

CONCLUSION

Among the edentulous, chronic infections like denture-related mucosal lesions are important determinants of elevated CRP, comparable to periodontal disease in the dentate. Elevated CRP per se and edentulism were not significantly associated with increased mortality. Periodontal disease was, however, still associated with a two-fold CVD mortality in this very old population.

Development of a point-of-care assay system for high-sensitivity C-reactive protein in whole blood

BACKGROUND

C-reactive protein (CRP) is emerging as a potential risk predictor for future cardiovascular diseases (CVD). High sensitivity assays have been developed and applied for clinical purposes.

METHODS

The fluorescence immunochromatographic assay was employed to detect and quantify CRP in whole blood. It consisted of a fluorescence (FL) antibody detector buffer, a test strip housed in a disposable cartridge, and a laser fluorescence scanner. Whole blood sample was mixed with detector, loaded onto a cartridge, incubated for 10 min, and the concentration of CRP was measured in a laser fluorescence scanner. The linearity, limit of detection (LOD), and performance of new assay system was tested and evaluated. The comparability of assay was examined with an automated reference method.

RESULTS

With the new assay system, a reliable correlation of coefficient (r) was obtained between the ratio value (A(T)/A(C)) and a concentration of CRP in samples. The linearity fell in the range of 0-10 mg/l of CRP, and the analytical detection limit was 0.133 mg/l of CRP. The mean recovery of the control was 105.2% in a working range. The precision of the intra- and inter-assay in a range of 0.5-6 mg/l was CVs <6% and <8%, respectively. The new fluorescence immunochromatographic assay system correlated well with a traditional immunoturbidimetric assay for quantification of CRP concentration (r=0.955, N=90).

CONCLUSION

The fluorescence immunochromatographic assay is fast, reliable, and a reproducible platform for point-of-care testing (POCT) of high-sensitive (hs)-CRP in whole blood.

Detecting vulnerable plaque using peripheral blood: inflammatory and cellular markers

The concept of the vulnerable patient has arrived. Enhanced diagnostic methods will eventually permit accurately finding and treating these patients and their disease. Clinical Cardiologists now recognize that coronary atherosclerosis is two pathophysiologically distinct syndromes: stable and unstable. Stable coronary syndromes result from fixed, severe stenoses limiting blood flow and causing secondary myocardial ischemia. The unstable acute coronary syndromes are frequently catastrophic and are pathophysiologically distinct. They result from different cell subsets causing vascular inflammatory syndromes rather than gradual lumen constriction by plaque. Though pathophysiologically distinct, they may show common pathophysiology when a ruptured plaque heals and progressively becomes a critical stenosis. For the present hs-CRP measurement is the strongest correlative factor for future clinical events due to arterial inflammation: myocardial infarction, unstable angina, stroke, and peripheral vascular disease in both diseased and apparently healthy, asymptomatic patients. The CRP plasma level also is the best risk assessment in patients with either stable or unstable angina, long term after myocardial infarction, and in patients undergoing revascularization therapies. One study showed the only independent cardiovascular risk indicators using multivariate, age adjusted and traditional risk analysis were CRP and Total/HDL cholesterol ratio. If CRP, IL-6, and ICAM-1 levels are added to lipid levels, risk assessment can be improved over lipids alone. The prevalence of high-risk subjects in the general population is low, amplifying diagnostic problems for vulnerable plaque. Since no test yet has high sensitivity or specificity, diagnostic errors are high, with many false positives and negatives. Sensitivity or specificity must be increased by developing a risk marker panel, or by simultaneously finding other markers that themselves are highly sensitive and specific for vulnerable plaque.

Hydroxymethylglutaryl coenzyme a reductase inhibitors down-regulate chemokines and chemokine receptors in patients with coronary artery disease

OBJECTIVES

We sought to investigate whether the activation of the chemokine network observed in patients with coronary artery disease (CAD) could be modified by treatment with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins).

BACKGROUND

Chemokines and chemokine receptors are important mediators in atherogenesis, and we hypothesized that the statins could affect the chemokine network in CAD.

METHODS

Thirty CAD patients without previous statin therapy were randomized to receive atorvastatin (80 mg/day, n = 15) or simvastatin (20 mg/day, n = 15). Peripheral blood mononuclear cells (PBMCs) and plasma were obtained at baseline and after six months of statin therapy. Messenger ribonucleic acid (mRNA) expression of chemokines and chemokine receptors in PBMCs was analyzed by ribonuclease protection assay and real-time reverse-transcription polymerase chain reaction. Chemokines were also examined in the supernatants from unstimulated and lipopolysaccharide-stimulated PBMCs (and in plasma).

RESULTS

Our main findings were: 1) gene expression of several chemokines (i.e., macrophage inflammatory protein [MIP]-1alpha, MIP-1beta, and interleukin [IL]-8) and chemokine receptors (i.e., CC chemokine receptor [CCR]1, CCR2, CCR4, and CCR5) was markedly increased among CAD patients compared with healthy control subjects; 2) treatment with atorvastatin and simvastatin markedly reduced the mRNA levels of some of these chemokines (i.e., MIP-1alpha, MIP-1beta, IL-8) and receptors (i.e., CCR1 and CCR2), with the most pronounced effect in the atorvastatin group; and 3) statin therapy reduced the spontaneous release of IL-8 and MIP-1alpha from PBMCs in CAD patients.

CONCLUSIONS

This study demonstrates a down-regulatory effect of statins on the chemokine network in CAD patients, possibly contributing to the beneficial effects of statins in this disorder.

Reduction of serum C-reactive protein by statin therapy may reflect decreased isoprenylation of Rac-1, a mediator of the IL-6 signal transduction pathway

Recent studies demonstrate that statin therapy decreases plasma levels of C-reactive protein (CRP), a potent risk factor for thrombotic vascular events. CRP is an acute phase reactant, and most circulating CRP is synthesized by hepatocytes in response to IL-6. Since statins do not appear to have a consistent impact on serum levels of IL-6, their impact on plasma CRP very likely reflects down-regulation of hepatocyte responsiveness to this cytokine. The ability of IL-6 to promote transcription of CRP is mediated, in large part, by activation of the transcription factor STAT3; this activation requires both a tyrosine phosphorylation (mediated by the IL-6 receptor complex) and a serine phosphorylation (Ser-727), the origin of which has been more obscure. There is new evidence that, when hepatocytes are exposed to IL-6, the consequent serine phosphorylation of STATS is mediated by a signal transduction pathway in which the G-protein Rac-1 plays an obligate role. Inasmuch as the proper function of Rac-1 is contingent on isoprenylation that anchors it to the plasma membrane, it is reasonable to hypothesize that statin therapy interferes with IL-6 signaling in hepatocytes by suppressing the isoprenylation of Rac-1; a decrease in the transcription of CRP would be a likely consequence of this effect. Whether or not a reduction in elevated CRP is directly beneficial to vascular health, statins can exert direct effects on vascular endothelial function that should help prevent vascular inflammation and thrombosis, and thus should be of particular benefit to subjects - such as those with high CRP levels - who are at high risk for vascular events.