High-dose atorvastatin enhances the decline in inflammatory markers in patients with acute coronary syndromes in the MIRACL study

Adipose Tissue, Inflammation, and Cardiovascular Disease

Mounting evidence highlights the role of adipose tissue in the development of a systemic inflammatory state that contributes to obesity-associated vasculopathy and cardiovascular risk. Circulating mediators of inflammation participate in the mechanisms of vascular insult and atheromatous change, and many of these inflammatory proteins are secreted directly from adipocytes and adipose tissue–derived macrophages. Several factors linking obesity with an increased cardiovascular risk have been identified. The adipocyte-specific secretory protein adiponectin is a particularly promising candidate in this context. Its levels are decreased in obesity. Adiponectin may mediate some of its demonstrated cardioprotective effects through its anti-inflammatory properties. In addition to decreased expression of beneficial adipokines, secretion of a host of inflammatory factors from visceral adipose tissue may contribute to the increased cardiovascular risk associated with obesity. The cardioprotective effects of many of the most popular drug regimens corroborate these conclusions, demonstrating that along with improvements in other therapeutic end points, they mediate improvements in systemic inflammation. In some cases, these improvements are attributable to direct suppression of inflammatory signaling in adipocytes. The targeted suppression of various proinflammatory cascades in adipocytes specifically represents an exciting new therapeutic opportunity for the cardiovascular disease area.

Beneficial effect of simvastatin and pravastatin treatment on adverse cardiac remodelling and glomeruli loss in spontaneously hypertensive rats

The aim of the present study was to investigate the possibility of different effects of the hydrophobic statin simvastatin and the hydrophilic statin pravastatin on the remodelling process in the overloaded left ventricle and renal cortex of SHRs (spontaneously hypertensive rats). Fifteen SHRs were treated for 40 days with simvastatin, pravastatin or placebo (water) via orogastric administration. Left ventricle and renal cortex were examined by light microscopy and stereology. LV (left ventricular) cardiomyocyte nuclei (N[cmn]) and glomeruli (N[gl]) numbers were estimated by the dissector method. BP (blood pressure) and serum triacylglycerols (triglycerides) were lower in the statin-treated groups than in the untreated control group. The volume density of the interstitial connective tissue was smaller and length density of the intramyocardial arteries, as well as the arteries/cardiomyocyte ratio, was greater in the statin-treated groups than in the control group. No difference was observed between the two statin-treated groups. The cross-sectional cardiomyocyte area was significantly smaller in the simvastatin-treated group than in the control or pravastatin-treated groups, and it was smaller in the pravastatin-treated group than in the control group. N[cmn] and N[gl] were greater in the two statin-treated groups than in the control group, but no significant difference was observed between the two statin-treated groups. In conclusion, administration of the statins simvastatin and pravastatin to SHRs effectively prevented the elevation in BP and serum triaclyglycerols, and also attenuated adverse cardiac and kidney remodelling by preventing LV hypertrophy, enhancing myocardial vascularization with the decrease in interstitial fibrosis and attenuating cardiomyocyte and glomerular loss.

Traditional and nontraditional cardiovascular risk factors in chronic kidney disease

Chronic kidney disease (CKD) is public health problem, with as many as 20 million individuals affected in the United States. Patients with CKD should be considered in the highest-risk group for development of cardiovascular disease (CVD), and aggressive treatment of traditional and nontraditional risk factors should be instituted. Additional randomized controlled trials are urgently needed to evaluate potential treatments in this population. This article focuses attention on the major modifiable cardiovascular risk factors in CKD.

Behavioural treatments for chronic systemic inflammation: effects of dietary weight loss and exercise training

Persistent low-grade inflammation, as indicated by higher circulating levels of inflammatory mediators such as C-reactive protein, interleukin-6 and tumour necrosis factor-alpha, is a strong risk factor for several chronic diseases. There are data indicating that decreasing energy intake and increasing physical activity may be effective therapies for reducing overall inflammation. Evidence is strong that circulating levels of inflammatory markers are elevated with total and abdominal obesity, possibly owing to a higher secretion rate of cytokines by adipose tissue in obese people. Moreover, very-low-energy dietary weight loss reduces both circulating markers of inflammation and adipose-tissue cytokine production. Data from several large population-based cohorts show an inverse association between markers of systemic inflammation and physical activity or fitness status; small-scale intervention studies support that exercise training diminishes inflammation. Dietary weight loss plus exercise is likely more effective than weight reduction alone in reducing inflammation. To date, data from randomized, controlled trails designed to definitively test the effects of weight loss or exercise training, or both, on inflammation are limited. Future studies are required to define the amount of weight loss needed for clinically meaningful reductions of inflammation; in addition, fully powered and controlled studies are necessary to clarify the effect of exercise training on chronic, systemic inflammation.

Role of cytokines in cardiovascular diseases: a focus on endothelial responses to inflammation

Complex cellular and inflammatory interactions are involved in the progress of vascular diseases. Endothelial cells, upon exposure to cytokines, undergo profound alterations of function that involve gene expression and de novo protein synthesis. The functional reprogramming of endothelial cells by cytokines is of importance especially in patients with chronic vascular inflammation. The intercellular network of dendritic cells, T-lymphocytes, macrophages and smooth muscle cells generates a variety of stimulatory cytokines [e.g. TNF-alpha (tumour necrosis factor-alpha), IL (interleukin)-1, IL-6 and IFN-gamma (interferon-gamma)] and growth factors that promote the development of functional and structural vascular changes. High concentrations of proinflammatory cytokines increase oxidative stress, down-regulate eNOS (endothelial nitric oxide synthase) bioactivity and induce endothelial cell apoptosis. Chemoattractant cytokines [e.g. VEGF (vascular endothelial growth factor), TGF-beta1 (transforming growth factor-beta1) and IL-8] are important regulators of inflammation-induced angiogenesis and are directly modulated by nitric oxide. This review will focus on the vascular mechanisms orchestrated by cytokines and summarizes the current knowledge concerning the contribution of cytokines to cardiovascular diseases.

High-density lipoprotein, but not low-density lipoprotein cholesterol levels influence short-term prognosis after acute coronary syndrome: results from the MIRACL trial

AIMS

Patients with acute coronary syndrome (ACS) in the Myocardial Ischaemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study had diminished cardiovascular events after 16 weeks of treatment of atorvastatin 80 mg daily. We determined whether plasma lipoproteins at baseline and then at 6 weeks after randomization predicted clinical outcome.

METHODS AND RESULTS

Cox proportional hazards models were constructed to determine relations between lipoproteins and clinical endpoint events. Baseline LDL cholesterol (LDL-C) did not predict outcome. In contrast, baseline HDL-C predicted outcome with a hazard ratio of 0.986 per mg/dL increment in HDL-C, P<0.001, indicating 1.4% reduction in risk for each 1 mg/dL increase in HDL-C. Atorvastatin treatment profoundly lowered LDL-C, but had minimal effect on HDL-C. Neither Week 6 LDL-C nor absolute change of LDL-C from baseline by Week 6 had any significant impact on clinical endpoints occurring between Week 6 and Week 16 after randomization.

CONCLUSION

Plasma HDL-C, but not LDL-C, measured in the initial stage of ACS predicts the risk of recurrent cardiovascular events over the ensuing 16 weeks. LDL-C reduction does not account for the clinical risk reduction with atorvastatin treatment after ACS. This finding may suggest that the clinical benefit of atorvastatin after ACS is mediated by qualitative changes in the LDL particle and/or by non-lipid (pleiotropic) effects of the drug.

Inflammatory markers at the site of ruptured plaque in acute myocardial infarction: locally increased interleukin-6 and serum amyloid A but decreased C-reactive protein

BACKGROUND

Acute myocardial infarction (AMI) is associated with inflammation. However, it remains unclear whether it originates from the ruptured plaque or represents a systemic process.

METHODS AND RESULTS

In 42 patients with AMI, a balloon-based embolization protection device and aspiration catheter (PercuSurge) were used during acute coronary interventions. Samples from the site of the ruptured plaque were taken under distal balloon occlusion. Systemic samples were taken from the aorta. Sera, plaques, and thrombi were analyzed for inflammatory markers and lipoproteins. Systemic levels of C-reactive protein (CRP), interleukin-6 (IL-6), and serum amyloid A (SAA) in the aorta amounted to 3.0 mg/L, 5.0 ng/L, and 22.1 mg/L, respectively (interquartile ranges [IQRs], 1.1 to 7.4 mg/L, 5.0 to 6.5 ng/L, and 13.9 to 27.0 mg/L, respectively). In blood surrounding ruptured plaques, local levels of IL-6 (8.9 ng/L; IQR, 5.0 to 16.9 ng/L) and SAA (24.3 mg/L; IQR, 16.3 to 44.0 mg/L) were significantly higher, whereas CRP levels (2.5 mg/L; IQR, 0.9 to 7.7 mg/L) were decreased compared with the aorta (all P<0.0001). The coronary levels of IL-6 determined in vivo showed biological activity in vitro. Harvested thrombus contained CD68-positive monocytes expressing IL-6 and showed extracellularly and intracellularly positive staining for SAA, whereas CRP was found exclusively in the cytoplasm of phagocyting white blood cells.

CONCLUSIONS

Coronary levels of IL-6 and SAA at the site of plaque rupture were increased relative to the systemic circulation, indicating local production of biologically active inflammatory mediators. In contrast, CRP was locally decreased, at least in part by uptake by the phagocyting cells, suggesting a systemic origin of the protein.

The bisphosphonate acute phase response: rapid and copious production of proinflammatory cytokines by peripheral blood gd T cells in response to aminobisphosphonates is inhibited by statins

The bisphosphonates are a novel class of drug that have been registered for various clinical applications worldwide. Bisphosphonates, and in particular the aminobisphosphonates (nBPs), are known to have a number of side-effects including a rise in body temperature and accompanying flu-like symptoms that resemble a typical acute phase response. The mechanism for this response has been partially elucidated and appears to be associated with the release of tumour necrosis factor (TNF)alpha and interleukin (IL)6, although the effector cells that release these cytokines and the mechanism of action remain enigmatic. Here, we show that the nBP-induced acute phase response differs from the typical acute phase response in that CD14+ cells such as monocytes and macrophages are not the primary cytokine producing cells. We show that by inhibiting the mevalonate pathway, nBPs induce rapid and copious production of TNFalpha and IL6 by peripheral blood gammadelta T cells. Prior treatment with statins, which inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, blocks nBP-induced production of these proinflammatory cytokines by gammadelta T cells and may offer a means of avoiding the associated acute phase response. In addition, our findings provide a further mechanism for the anti-inflammatory effects attributed to inhibitors of HMG CoA reductase.

Atorvastatin has an important acute anti-inflammatory effect in patients with acute coronary syndrome: results of a randomized, double-blind, placebo-controlled study

BACKGROUND

C-reactive protein (CRP) levels are associated with cardiovascular risk. We assessed the hypothesis that atorvastatin might have anti-inflammatory effects in acute coronary syndromes (ACS) as shown by CRP reduction.

METHODS

This study was a prospective, randomized, double-blind, placebo-controlled study of 90 consecutive patients admitted within 48 hours of onset of ACS with CRP levels > or =1.4 mg/dL. Patients were assigned to atorvastatin 40 mg daily or placebo over 30 days. C-reactive protein levels, lipid profiles, serum fibrinogen, white cell count, and erythrocyte sedimentation rate were measured at entry, hospital discharge, and 1 month later.

RESULTS

Baseline clinical characteristics did not differ between atorvastatin and placebo groups (mean age 59.3 +/- 13.4 vs 61.1 +/- 11.5, P = ns); myocardial infarction 52.3% versus 67.4% ( P = ns). In both groups, median baseline CRP levels were comparable (5.97 +/- 6.2 vs 4.64 +/- 4.2 mg/dL, P = ns). C-reactive protein levels were lower in the atorvastatin group versus control group at discharge (1.68 +/- 1.65 vs 4.12 +/- 4.18 mg/dL) and at 30 days (0.50 +/- 0.71 vs 2.91 +/- 2.68 mg/dL, both P < .0001). C-reactive protein levels significantly decreased from baseline to discharge and 1 month later in placebo and atorvastatin groups (both P < .0001); however, the reduction was greater in the atorvastatin group (62% vs 11% at discharge [P < .0001]; 84% vs 30% at 1 month [P < .0001]). In addition, atorvastatin was associated with a reduction in total and low-density lipoprotein cholesterol and erythrocyte sedimentation rate at discharge and at 30 days (P < .0001 for all comparisons). No correlation was found between changes in CRP and cholesterol levels.

CONCLUSIONS

C-reactive protein levels in ACS were rapidly reduced with atorvastatin. These data provide evidence that statins have fast and early anti-inflammatory effects in addition to lipid-lowering effects in ACS.

C-reactive protein levels and outcomes after statin therapy

BACKGROUND

Statins lower the levels of low-density lipoprotein (LDL) cholesterol and C-reactive protein (CRP). Whether this latter property affects clinical outcomes is unknown.

METHODS

We evaluated relationships between the LDL cholesterol and CRP levels achieved after treatment with 80 mg of atorvastatin or 40 mg of pravastatin per day and the risk of recurrent myocardial infarction or death from coronary causes among 3745 patients with acute coronary syndromes.

RESULTS

Patients in whom statin therapy resulted in LDL cholesterol levels of less than 70 mg per deciliter (1.8 mmol per liter) had lower event rates than those with higher levels (2.7 vs. 4.0 events per 100 person-years, P=0.008). However, a virtually identical difference was observed between those who had CRP levels of less than 2 mg per liter after statin therapy and those who had higher levels (2.8 vs. 3.9 events per 100 person-years, P=0.006), an effect present at all levels of LDL cholesterol achieved. For patients with post-treatment LDL cholesterol levels of more than 70 mg per deciliter, the rates of recurrent events were 4.6 per 100 person-years among those with CRP levels of more than 2 mg per liter and 3.2 events per 100 person-years among those with CRP levels of less than 2 mg per liter; the respective rates among those with LDL cholesterol levels of less than 70 mg per deciliter were 3.1 and 2.4 events per 100 person-years (P<0.001). Although atorvastatin was more likely than pravastatin to result in low levels of LDL cholesterol and CRP, meeting these targets was more important in determining the outcomes than was the specific choice of therapy. Patients who had LDL cholesterol levels of less than 70 mg per deciliter and CRP levels of less than 1 mg per liter after statin therapy had the lowest rate of recurrent events (1.9 per 100 person-years).

CONCLUSIONS

Patients who have low CRP levels after statin therapy have better clinical outcomes than those with higher CRP levels, regardless of the resultant level of LDL cholesterol. Strategies to lower cardiovascular risk with statins should include monitoring CRP as well as cholesterol.

C-reactive protein comes of age

Cardiovascular disease remains a leading cause of death throughout the world despite advances in its detection and treatment. Commonly used risk algorithms, such as the Framingham Risk Score fail to identify all affected individuals. Novel cardiovascular risk factors that identify these missed individuals would greatly improve overall care of patients. C-reactive protein (CRP), an inflammatory biomarker, has emerged as a leading candidate to fulfill this role. Based on the results of several prospective epidemiologic studies, CRP has emerged as one of the most powerful predictors of cardiovascular disease. This marker provides valuable information to clinicians in various clinical settings, ranging from overt cardiovascular disease, stable angina, presenting acute coronary syndromes and peripheral vascular disease, to the metabolic syndrome. Furthermore, CRP has been demonstrated to actively contribute to all stages of atherogenesis, participating in endothelial dysfunction, atherosclerotic-plaque formation, plaque maturation, plaque destabilization and eventual rupture. Thus, it might also serve as a therapeutic target. It is our contention that the future will see much wider use of CRP and CRP-driven therapies in clinical medicine, improving our ability to identify and manage cardiovascular disease.

Lipid and non-lipid effects of statins

Long- and short-term trials with the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have demonstrated significant reductions in cardiovascular events in patients with and without history of coronary heart disease. Statins are well-established low-density lipoprotein (LDL)-lowering agents, but their clinical benefit is believed to result from a number of lipid and non-lipid effects beyond LDL lowering, including a rise in plasma high-density lipoprotein levels. Beyond improving the lipid profile, statins have additional non-lipid effects including benefit on endothelial function, inflammatory mediators, intima-media thickening, prothombotic factors that ultimately result in plaque stabilization. These effects arise through the inhibition of several mevalonate-derived metabolites other than cholesterol itself, which are involved in the control of different cellular functions. Although statins represent the gold standard in the prevention and treatment of coronary heart disease, combination therapy with other lipid-lowering drugs, as well as novel therapeutic indications, may increase their therapeutic potential.

Intensive statin therapy in acute coronary syndromes: clinical benefits and vascular biology

PURPOSE OF REVIEW

The results of a landmark clinical study comparing intensive statin therapy with conventional statin therapy, in patients with acute coronary syndromes (ACS), are reviewed. The mechanisms behind these results are analysed drawing data from vascular and cell biology.

RECENT FINDINGS

The Pravastatin or Atorvastatin Evaluation and Infection Therapy-Thrombolysis in Myocardial Infarction (PROVE IT-TIMI 22) study showed that intensive statin therapy with 80 mg of atorvastatin to achieve a low-density lipoprotein cholesterol of 62 mg/dl resulted in a 3.9% absolute and a 16% relative risk reduction in death or major cardiovascular events up to 2 years, compared to 40 mg of pravastatin, in patients with ACS. The results were especially significant as intensive statin therapy resulted in a very early benefit (<30 days) and occurred against a background of percutaneous coronary intervention (69%) for the index admission and high use of medications for secondary prevention. The PROVE IT and the Myocardial Ischaemia Reduction with Aggressive Cholesterol Lowering (MIRACL) C-reactive protein sub-study also showed that atorvastatin (80 mg) resulted in a significant reduction in markers of inflammation, whilst the Reversal of Atherosclerosis with Aggressive Lipid Lowering (REVERSAL) study showed that intensive statin therapy was associated with reduced progression of atherosclerosis compared with conventional doses of statins.

SUMMARY

Intensive statin therapy results in a significant early reduction in adverse cardiac events in ACS patients which are sustained over 2 years. The early benefits seen are likely to result from modulation of inflammation, endothelial function and coagulation, i.e. the pleiotropic effects, whereas the greater reduction in low-density lipoprotein cholesterol results in reduced long-term events.

Simvastatin prevents vascular hyporeactivity during inflammation

BACKGROUND

There is growing evidence that statins exert anti-inflammatory and antioxidative vascular actions that are independent of lipid lowering. We tested whether hyporeactivity to the endothelium-dependent vasodilator acetylcholine (ACh) and the vasoconstrictor norepinephrine (NE) during acute experimental inflammation could be prevented by simvastatin.

METHODS AND RESULTS

In a randomized, placebo-controlled, parallel group study, forearm blood flow (FBF) responses to NE, ACh, and the endothelium-independent vasodilator nitroglycerin (NTG) were assessed at baseline, after 4 days of simvastatin 80 mg PO or placebo treatment, and during Escherichia coli endotoxin (lipopolysaccharide [LPS])-induced inflammation in 20 healthy volunteers. Additionally, markers of inflammation and neutrophil oxidative burst were assessed. Simvastatin and placebo had no effect on FBF or oxidative/inflammatory markers. LPS administration decreased the responses of FBF to NE by 43% (P<0.05) and decreased responses to ACh by 48% (P<0.05) but did not decrease FBF responses to NTG. Simvastatin completely preserved responses to NE and to ACh. The LPS-induced increases in neutrophil oxidative burst and plasma tumor necrosis factor-alpha concentrations were mitigated by simvastatin (P<0.05 versus placebo).

CONCLUSIONS

This study demonstrates potent vasoprotective properties of high-dose simvastatin during endotoxemia that may be useful for patients with acute systemic inflammation and associated vascular hyporeactivity.

Immunogenetic Susceptibility of Atherosclerotic Stroke

The understanding of the pathophysiology governing atherosclerosis supports a prominent role for inflammation pathways in plaque initiation and progression that result in stroke and myocardial infarction. Elevated levels of inflammatory markers in the blood, such as C-reactive protein and CD40 ligand/CD40, in concert with increased expression of adhesion molecules, chemokines, cytokines, matrix metalloproteinases (MMP), and inflammatory cells in the plaque, characterize the symptomatic atherothrombotic state. Advances in predictive capabilities of vascular events using a number of these biomarkers are beginning to remodel our clinical practice in the use of medications such as statins and angiotensin receptor blockers for stroke prevention. Although the general inflammatory features of atherosclerosis are becoming widely recognized, factors resulting in individual variability in plaque formation and instability remain poorly defined. Emerging literature points toward several acquired and innate susceptibility factors in the immune pathways that may provide insight into why many plaques rapidly evolve from a “stable” to an “unstable” or symptomatic state. First, exposure of plaque memory T-lymphocytes to infectious or endogenous antigens may result in rapid clonal expansion of T-cell variable β chain subtypes and stimulate macrophages to release MMPs, causing plaque destabilization. The effects of infectious agents can further be influenced by an individual’s major histocompatibility complex class II molecule profiles, which can affect susceptibility to specific organisms. Second, functional polymorphisms of genes that regulate the immune pathway can predispose patients to a more robust inflammatory expression after risk factor exposure. Identification of a susceptibility gene profile and immunologic mediators that promote T-cell activation provides a unique opportunity for early identification of stroke risk and targets for future therapy.

Effect of low dose atorvastatin versus diet-induced cholesterol lowering on atherosclerotic lesion progression and inflammation in apolipoprotein E*3-Leiden transgenic mice

OBJECTIVE

To evaluate whether low-dose atorvastatin suppresses atherosclerotic lesion progression and inflammation in apolipoprotein E*3 (apoE*3)-Leiden mice beyond its cholesterol-lowering effect.

METHODS AND RESULTS

ApoE*3-Leiden mice were fed a high-cholesterol (HC) diet until mild atherosclerotic lesions had formed. Subsequently, HC diet feeding was continued or mice received HC supplemented with 0.002% (w/w) atorvastatin (HC+A), resulting in 19% plasma cholesterol lowering, or mice received a low-cholesterol (LC) diet to establish a plasma cholesterol level similar to that achieved in the HC+A group. HC+A and LC diet reduced, significantly and to the same extent, lesion progression and complication in the aortic root, as assessed by measuring total atherosclerotic lesion area, lesion severity, and macrophage and smooth muscle cell area. In the aortic arch, HC+A but not LC blocked lesion progression. HC+A and LC reduced vascular inflammation (ie, expression of macrophage migration inhibitory factor , plasminogen activator inhibitor- 1, matrix metalloproteinase-9), but HC+A additionally suppressed vascular cell adhesion molecule-1 expression and, in parallel, monocyte adhesion. In contrast, low-dose atorvastatin showed no antiinflammatory action toward hepatic inflammation markers (serum amyloid A, C-reactive protein [CRP]) in apoE*3-Leiden mice and human CRP transgenic mice.

CONCLUSIONS

Low-dose atorvastatin cholesterol-dependently reduces lesion progression in the aortic root but shows antiinflammatory vascular activity and tends to retard atherogenesis in the aortic arch beyond its cholesterol-lowering effect.

Inflammation in atherosclerosis and implications for therapy

Atherosclerosis is now understood to be a disease characterized by inflammation that results in a host of complications, including ischemia, acute coronary syndromes (unstable angina pectoris and myocardial infarction), and stroke. Inflammation may be caused by a response to oxidized low-density lipoproteins, chronic infection, or other factors; and markers of this process, such as C-reactive protein, may be useful to predict an increased risk of coronary heart disease. Thus, we believe that inflammatory processes may be potential targets of therapy in preventing or treating atherosclerosis and its complications.

Statins: potent vascular anti-inflammatory agents

Atherosclerosis is a multifactorial condition that can result in cardiovascular disease. Statin therapy is thought to mediate cardioprotective effects that influence endothelial function, inflammatory responses, plaque stability and thrombus formation, processes involved in atherosclerosis. Although reduction in low-density lipoprotein cholesterol (LDL-C) potentially plays a role in all of these effects, several lines of evidence also implicate nonlipidmediated 'pleiotropic' effects. For example, statin therapy confers a lower risk for coronary heart disease than placebo in patients with comparable serum cholesterol levels, and confers a greater magnitude of clinical benefit than expected based on LDL-C levels alone. Moreover, while nonstatin lipid-lowering therapy does not necessarily reduce stroke risk, statins have shown a significant reduction in stroke. Statins exert their pleiotropic effects, in part, by improving endothelial function via up-regulation of endothelial nitric oxide synthase enzyme activity. Markers of inflammation such as high sensitivity C-reactive protein have been also shown to add further prognostic information about patients at risk of cardiovascular disease who may benefit from statin therapy. Further studies are still needed to determine whether statins have direct effects on inflammatory pathways.

Statins are associated with a reduced incidence of perioperative mortality after coronary artery bypass graft surgery

BACKGROUND

Statin therapy in nonsurgical patient populations is associated with a significant reduction in adverse cardiovascular events, including death, myocardial infarction (MI), and stroke. Recently, statin therapy was shown to be associated with a reduced incidence of postoperative mortality in patients undergoing major noncardiac vascular surgery. We investigated the influence of preoperative statin therapy on adverse outcomes after primary coronary artery bypass graft (CABG) surgery.

METHODS AND RESULTS

A retrospective cohort study of patients undergoing primary CABG surgery with cardiopulmonary bypass (CPB) (n=1663) between January 1, 2000 and December 31, 2001 at the Texas Heart Institute was performed. Patients were classified into 2 groups: patients receiving preoperative statin therapy (n=943) and patients not receiving preoperative antihyperlipidemic therapy (n=720). To determine if preoperative statin therapy was independently associated with a reduction in the risk of adverse postoperative outcomes, multivariate stepwise logistic regression was performed controlling for patient demographics, medical history, and preoperative medications. Multivariate logistic regression analysis demonstrated that preoperative statin therapy was independently associated with a significant reduction ( approximately 50%) in the risk of 30-day all-cause mortality (3.75% versus 1.80%; P<0.05). The adjusted odds ratio for early mortality in patients receiving preoperative statin therapy compared with patients not receiving antihyperlipidemic agents was 0.53 (95% CI, 0.28 to 0.99). Statin therapy was not independently associated with a reduced risk of postoperative MI, cardiac arrhythmias, stroke, or renal dysfunction. In an attempt to further control for selection bias related to the choice of therapy, multivariate analysis of a propensity-matched cohort of 1362 patients revealed that preoperative statin therapy was independently associated with a significant reduction in the composite endpoint of 30-day all-cause mortality and stroke (7.1% versus 4.6%; P<0.05).

CONCLUSIONS

Preoperative statin therapy may reduce the risk of early mortality after primary CABG surgery with CPB.

High-Dose Atorvastatin Reduces Total Plasma Levels of Oxidized Phospholipids and Immune Complexes Present on Apolipoprotein B-100 in Patients With Acute Coronary Syndromes in the MIRACL Trial

BACKGROUND

Oxidized phospholipids (OxPL) are present within atherosclerotic plaques and bound by lipoprotein (a) [Lp(a)] in plasma. This study evaluated the impact of atorvastatin on oxidized LDL (OxLDL) in patients with acute coronary syndromes (ACS).

METHODS AND RESULTS

OxLDL-E06 (OxPL content on apolipoprotein B-100 [apoB] detected by antibody E06), apoB-100 immune complexes (apoB-IC), OxLDL autoantibodies, and Lp(a) levels were measured in 2341 patients at baseline and after 16 weeks of treatment with atorvastatin 80 mg/d or placebo. The OxLDL-E06 and apoB-IC data are reported per apoB-100 particle (OxPL/apoB, IC/apoB) and as total levels on all apoB-100 particles (total apoB-OxPL and total apoB-IC [eg, OxPL/apoB or IC/apoBxapoB-100 levels]). Compared with baseline values, atorvastatin reduced apoB-100 (-33%), total apoB-OxPL (-29.7%), total apoB-IC IgG (-29.5%), and IgM (-25.7%) (P<0.0001 for all), whereas no change or an increase was observed with placebo. When normalized per apoB-100, compared with placebo, atorvastatin increased OxPL/apoB (9.5% versus -3.9%, P<0.0001) and Lp(a) (8.8% versus -0.7%, (P<0.0001). A strong correlation was noted between OxPL/apoB and Lp(a) (R=0.85, P<0.0001), consistent with previous data that Lp(a) binds OxPL.

CONCLUSIONS

After atorvastatin treatment, total OxPL on all apoB-100 particles was decreased. However, there was enrichment of OxPL on a smaller pool of apoB-100 particles, in parallel with similar increases in Lp(a), suggesting binding by Lp(a). These data support the hypothesis that atorvastatin promotes mobilization and clearance of proinflammatory OxPL, which may contribute to a reduction in ischemic events after ACS.

Effects of statin therapy on vascular dysfunction

Dyslipidemia and vascular inflammation play critical roles in the onset of acute coronary syndromes including myocardial infarction. Recent advances in cardiovascular medicine demonstrate that lipid-lowering therapy by 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) prevents acute coronary complications, probably by limiting inflammation in atheroma. Although a number of studies have suggested various effects of statins on vascular dysfunction independent of lipid lowering, the clinical benefits of such effects are not established as yet.

Effect of Atorvastatin on Risk of Recurrent Cardiovascular Events After an Acute Coronary Syndrome Associated With High Soluble CD40 Ligand in the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) Study

Background— Patients with acute coronary syndromes have elevated plasma levels of the proinflammatory, prothrombotic cytokine CD40 ligand (sCD40L). Statins inhibit CD40L signaling in vitro, but there are no prospective studies of statins and sCD40L in acute coronary syndromes.

Methods and Results— We measured sCD40L in subjects with an acute coronary syndrome enrolled in the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study. Subjects were randomized in this double-blind trial to atorvastatin 80 mg/d or placebo for 16 weeks. Plasma CD40L was measured from 2908 (94%) of 3086 subjects at baseline and 2352 (76%) at 16 weeks. Odds ratios (ORs) and 95% CIs from logistic regression models assessed the risk of recurrent cardiovascular events over 16 weeks (death, nonfatal myocardial infarction, cardiac arrest, and worsening angina requiring rehospitalization) in the placebo group from baseline sCD40L and the effect of atorvastatin on the risk associated with CD40L in all subjects. The effects of atorvastatin on plasma concentrations of CD40L were assessed by Wilcoxon tests. There was a threshold effect, with only high sCD40L (>90th centile) being a risk factor for a recurrent cardiovascular event (OR 1.86, 95% CI 1.25 to 2.77). This risk was abolished by atorvastatin (OR 1.09, 95% CI 0.69 to 1.76), which reduced the risk by 48%. Atorvastatin had only a modest effect on sCD40L ( P =0.08).

Conclusions— In patients with acute coronary syndromes, atorvastatin abrogated the risk of recurrent cardiovascular events associated with high sCD40L. Early statin therapy after acute coronary syndromes counters the risk associated with elevated sCD40L.

Beyond the laboratory: clinical implications for statin pleiotropy

Results from large-scale clinical trials of lipid lowering with 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) have led to a revolution in the management of atherosclerosis. In addition to their potent effect on serum lipid levels, statins influence several other cellular pathways, including those involving inflammatory, oxidative, and thrombotic processes. These effects clearly have the potential to beneficially modify the atherogenic process, and it has been suggested that they contribute to the impressive results seen in the clinical trials. We review the clinical evidence for benefits of statin therapy that are distinct from their effect on lipid biology. In particular, we address three key issues: the role of statins in diseases not traditionally associated with elevated cholesterol levels; whether clinical benefits are seen with statin therapy before an effect on lipid levels; and whether the magnitude of clinical benefit observed with statin therapy is unrelated to the degree of cholesterol reduction. At present, low-density-lipoprotein lowering seems to be the primary mechanism underlying the clinical benefits of statin therapy and should remain the focus of risk-reduction strategies in clinical practice.

Evidence for anti-inflammatory activity of statins and PPARα activators in human C-reactive protein transgenic mice in vivo and in cultured human hepatocytes in vitro

Inflammatory processes, aside from cholesterol, play a central role in atherogenesis. Human C-reactive protein (huCRP) signals systemic inflammation and independently predicts future cardiovascular risk. Cholesterol-lowering statins reduce atherosclerosis and plasma huCRP levels. Evidence is sought for a direct anti-inflammatory statin effect in vivo, independent of effects on plasma cholesterol and atherogenesis. The effect of atorvastatin and simvastatin on huCRP expression was studied in nonatherosclerotic huCRP transgenic mice and compared with another class of hypolipidemic drugs, peroxisome proliferator-activated receptor-alpha (PPARα) activators, notably fenofibrate and Wy14643. Like statins, PPARα activators combine antiatherosclerotic properties with huCRP-lowering effects. Dietary treatment with statins or PPARα activators decreased basal and interleukin-1β (IL-1β)-induced plasma huCRP levels independently of cholesterol lowering. These direct anti-inflammatory in vivo effects occurred at the transcriptional level and could be confirmed in cultured human liver slices and in human hepatoma cells transiently transfected with a huCRP promoter-driven luciferase reporter. A molecular rationale for the suppression of IL-1-induced huCRP transcription is provided by showing that statins and PPARα activators up-regulate IκBα protein expression. This results in a reduced nuclear translocation of p50-nuclear factor κ B (NFκB) and thereby decreased amounts of nuclear p50-NFκB∼CCAAT/enhancer binding protein beta (C/EBPβ) complexes, which determine the huCRP transcription rate. Our results provide conclusive evidence for a direct suppressive effect of statins and PPARα activators on huCRP expression independent of cholesterol lowering and atherogenesis. (Blood. 2004;103:4188-4194)

Soluble CD40 Ligand, Soluble P-Selectin, Interleukin-6, and Tissue Factor in Diabetes Mellitus

Background— High levels of the soluble fragment of CD40 ligand (sCD40L) have previously been associated with adverse cardiovascular outcomes. CD40L–CD40 interaction has been linked to the pathogenesis of atherothrombotic complications in cardiovascular disease (CVD). We sought to determine whether a “package of care” of intensified multifactorial cardiovascular risk intervention could reduce indices of platelet activation, inflammation, and coagulation in diabetes and whether patients with overt CVD would derive similar benefit compared with those without.

Methods and Results— We measured plasma sCD40L, soluble P-selectin (sP-sel, an index of platelet activation), interleukin-6 (IL-6, a proinflammatory cytokine), and tissue factor (TF, an initiator of coagulation) in 97 patients with diabetes mellitus (41 with and 56 without overt CVD) and 39 comparable healthy control subjects. Thirty-six patients with and 32 without overt CVD then participated in a package of care of cardiovascular risk intervention over a period of 1 year. Plasma levels of sCD40L ( P <0.001), sP-sel ( P <0.001), IL-6 ( P =0.001), and TF ( P <0.001) were higher in patients with diabetes than in control subjects, with TF levels highest in patients with overt CVD. Multifactorial intervention was associated with significant reductions in sCD40L in both patient groups (both P <0.001), but reductions in sP-sel and TF were seen only in patients without overt CVD. There was no significant change in IL-6 levels in both patient groups.

Conclusions— Intensive multifactorial risk management can reduce high levels of sCD40L but can only partially correct abnormal platelet activation, inflammation, and coagulation in diabetes, particularly in patients with overt CVD.