A review of high-dose statin therapy: targeting cholesterol and inflammation in atherosclerosis

Attainment of Canadian and European guidelines' lipid targets with atorvastatin plus ezetimibe vs. doubling the dose of atorvastatin

BACKGROUND

Canadian and European treatment guidelines identify low-density lipoprotein cholesterol (LDL-C) as a primary treatment target for hypercholesterolaemia.

OBJECTIVES

This post hoc analysis compared ezetimibe 10 mg (ezetimibe) added to atorvastatin vs. doubling the atorvastatin dose on achievement of the 2009 Canadian Cardiovascular Society (CCS) and the 2007 Joint European Prevention Guidelines primary and optional secondary lipid targets and high-sensitivity C-reactive protein (hs-CRP) levels.

METHODS

After stabilisation on atorvastatin, hypercholesterolaemic patients at moderately high risk (MHR) for coronary heart disease (CHD) not at LDL-C < 2.6 mmol/l were randomised to atorvastatin 20 mg vs. doubling their atorvastatin dose to 40 mg; and patients at high risk (HR) for CHD not at LDL-C < 1.8 mmol/l were randomised to atorvastatin 40 mg plus ezetimibe vs. doubling their atorvastatin dose to 80 mg for 6 weeks.

RESULTS

When treated with atorvastatin plus ezetimibe, MHR and HR patients had greater attainment of LDL-C, most lipids and lipoproteins and/or hs-CRP targets compared with doubling their atorvastatin dose. More MHR and HR patients achieved dual targets of LDL-C and: Apolipoprotein (Apo) B, total cholesterol (total-C), total-C/high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides, Apo B/Apo A-I or hs-CRP with ezetimibe + atorvastatin treatment compared with doubling their atorvastatin dose.

CONCLUSIONS

These results demonstrated greater achievement of single/dual treatment targets as set by Canadian and European treatment guidelines with ezetimibe added to atorvastatin 20 mg or 40 mg compared with doubling the atorvastatin dose to 40 mg or 80 mg in MHR and HR patients, respectively.

Rimonabant inhibits TNF-α-induced endothelial IL-6 secretion via CB1 receptor and cAMP-dependent protein kinase pathway

AIM

To investigate whether rimonabant, a cannabinoid receptor antagonist, had inhibitory effects on inflammatory reactions in human umbilical vein endothelial cells (HUVEC).

METHODS

TNF-α-induced IL-6 production was measured by ELISA and effects on related signaling pathways were investigated by immunoblot analysis. Cellular cAMP level was measured using kinase-coupled luciferase reaction.

RESULTS

Rimonabant at 1 and 10 μmol/L significantly inhibited TNF-α-induced IL-6 production when added 15, 30 and 60 minutes before TNF-α treatment. Rimonabant also inhibited TNF-α-induced phosphorylation of IκB kinase (IKK) α/β and IκB-α degradation. ACEA, a cannabinoid receptor subtype 1 (CB1) agonist, added before rimonabant abolished the former effects of rimonabant. H-89, an inhibitor of cAMP-dependent protein kinase (PKA), abolished the inhibitory effects of rimonabant on TNF-α induced IL-6 production. Rimonabant also increased the phosphorylation of PKA regulatory subunit II (PKA-RII), implying the essential role of PKA activation in the inhibitory effects of rimonabant. Treatment with the phosphatidylinositol 3-kinase (PI3K) inhibitor, wortmannin did not abolish the inhibitory effects of rimonabant on TNF-α induced IL-6 production.

CONCLUSION

Rimonabant had anti-inflammatory effects on endothelial cells and inhibited TNF-α-induced IKKα/β phosphorylation, IκB-α degradation and IL-6 production in HUVEC. This effect was related to CB1 antagonism and PKA activation.

Determination of simvastatin-induced changes in bone composition and structure by Fourier transform infrared spectroscopy in rat animal model

Simvastatin is a hypolipidemic drug which is used to control hypercholesterolemia and to prevent cardiovascular disease. In the current study, the effects of high and low doses of simvastatin treatment on tibia of healthy rats were investigated. Wistar rats were used for the control, 20mg and 50mg simvastatin-treated groups. Molecular investigations were performed using Fourier transform infrared spectroscopy. In the bones of the two groups of simvastatin-treated rats, the relative mineral/matrix ratio (p<0.001), relative carbonate content (p<0.001), carbonate/amide I ratio (p<0.001) and crystallinity (p<0.001) decreased significantly compared to the control group. Low dose of simvastatin treatment is more effective in reducing the relative carbonate content indicating the amount of carbonate substitution for phosphate in the mineral crystal. The olefinic band almost disappeared in the high dose of simvastatin-treated group which implies a decrease in unsaturation and an increase in lipid peroxidation. The higher frequency value and the bandwidth of CH(2) asymmetric stretching band for the 50mg treated group imply more disordered (p<0.001) and fluid (p<0.001) membrane structure. Low dose of simvastatin is more effective in strengthening the bone than high dose simvastatin treatment. High dose simvastatin treatment induces lipid peroxidation and changes the lipid composition and concentration, which are known to affect membrane physical properties.

Traditional Chinese medication Tongxinluo dose-dependently enhances stability of vulnerable plaques: a comparison with a high-dose simvastatin therapy

This study was carried out to test the hypothesis that Tongxinluo (TXL) as a Chinese herbal medicine enhances stability of vulnerable plaque dose dependently via lipid-lowering and anti-inflammation effects, similar to a high-dose simvastatin therapy. After abdominal aortic balloon injury, 75 rabbits were fed a 1% cholesterol diet for 10 wk and were then divided into five groups for 8-wk treatment: control group, low-dose TXL group, moderate-dose TXL group, high-dose TXL group, and high-dose simvastatin group. At the end of week 16, an adenovirus containing p53 was injected into the abdominal aortic plaques. Two weeks later, plaque rupture was induced by pharmacological triggering. The incidence of plaque rupture in all treatment groups (14.3%, 7.1%, 7.7%, and 7.1%) was significantly lower than that in control group (73.3%; P > 0.01). TXL dose-dependently lowered serum lipid levels and inhibited systemic inflammation. Corrected acoustic intensity and fibrous cap thickness of the aortic plaques were significantly increased, whereas plaque area, plaque burden, vulnerable index, and expression of oxidized low-density lipoprotein (ox-LDL) receptor 1, matrix metalloproteinase 1 (MMP-1), MMP-3, tissue inhibitor of MMP 1, and NF-κB in plaques were markedly reduced in all treatment groups when compared with the control group. Similar to high-dose simvastatin group, high-dose TXL group exhibited a low serum level of low-density lipoprotein cholesterol and ox-LDL, a low expression level of systemic and local inflammatory factors and a low plaque vulnerability index, with no differences in the incidence of plaque rupture among all treatment groups. TXL dose-dependently enhances the stability of vulnerable plaques and prevents plaques from rupture. Simvastatin and TXL offer similar protection in terms of lipid-lowering, anti-inflammation, and antioxidation effects.

Statins inhibit cyclooxygenase-2 and matrix metalloproteinase-9 in human endothelial cells: anti-angiogenic actions possibly contributing to plaque stability

AIMS

Cyclooxygenase (COX)-2 expression is increased in inflammation and angiogenesis and also in atherosclerotic plaques, where it co-localizes with metalloproteinases (MMPs) involved in the fibrous cap weakening. Insight into the regulation of COX-2 and MMP-9 expression suggests the involvement of a Rho-dependent pathway. Because statins interfere with Rho activation, we investigated the statin effect on COX-2 and MMP expressions in the human endothelium.

METHODS AND RESULTS

Simvastatin and atorvastatin were incubated with endothelial cells for 12 h before stimulation with phorbol myristate acetate or tumour necrosis factor-alpha, for times suitable to assess the endothelial tube differentiation on Matrigel and COX-2 and MMPs activities, proteins, and mRNA expressions. At 0.1-10 micromol/L, both statins reduced COX-2 expression and activity, without affecting COX-1. The statin effect was reversed by mevalonate and geranylgeranyl-pyrophosphate and mimicked by the Rho inhibitor C3 transferase, indicating the involvement of Rho in the signal transduction pathway leading to COX-2 expression. In parallel, statins, as well as COX-2 inhibitors, reduced the MMP-9 stimulated release and the endothelial tubular differentiation.

CONCLUSION

In the human vascular endothelium, statins reduce COX-2 and MMP-9 expression and activity. Through this mechanism, statins exert an anti-angiogenic effect possibly contributing to the cholesterol-lowering-unrelated protective effects of statins against plaque inflammatory angiogenesis and rupture.

Pivotal role of inflammation in vascular endothelial dysfunction of hyperlipidemic rabbit and effects by atorvastatin

AIMS

To evaluate the role of inflammation in vascular endothelial function of hyperlipidemic rabbits and atorvastatin's effects on it.

METHODS

22 rabbits were divided into high-fat diet and atorvastatin plus high-fat diet group. Basic levels of total and low-density lipoprotein cholesterol, triglyceride, C-reactive protein (CRP), interleukin-6 (IL-6), nitric oxide (NO), endothelin-1 (ET-1), fasting blood glucose (FBG), insulin and endothelial function were measured when grouping. Eight weeks later, all above parameters were remeasured and repeated again at days 1, 4 and 7 after atorvastatin withdrawal.

RESULTS

Eight-week high-fat diet could not cause the changes of FBG and insulin, but significantly induce increased blood lipids as well as inflammatory markers, imbalance between ET-1 and NO, and direct endothelial dysfunction, which could be significantly improved by atorvastatin therapy but could not be well controlled to near baseline. Abrupt withdrawal of atorvastatin caused sharp increase of inflammatory markers and endothelial dysfunction at days 4 and 7 after atorvastatin withdrawal independent of the changes of blood lipids.

CONCLUSIONS

High-fat diet could cause endothelial dysfunction associated with inflammation, and atorvastatin could counter-regulate it. Sudden withdrawal of statins could induce rebound of inflammatory response and endothelial dysfunction independent of changes of lipids, which may be responsible for increased cardiovascular events in patients with coronary artery disease after withdrawing statins.

Clinical significance of the humoral immune response to modified LDL

Human low density lipoprotein (LDL) undergoes oxidation and glycation in vivo. By themselves, oxidized LDL (oxLDL) and AGE-LDL have proinflammatory properties and are considered atherogenic. But the atherogenicity of these lipoproteins are significantly increased as a consequence of the formation of immune complexes (IC) involving specific autoantibodies. OxLDL and AGE antibodies have been shown to be predominantly of the IgG1 and IgG3 isotypes. OxLDL antibodies are able to activate the complement system by the classical pathway and to induce FcR-mediated phagocytosis. In vitro and ex vivo studies performed with modified LDL-IC have proven their pro-inflammatory and atherogenic properties. Clinical studies have demonstrated that the levels of circulating modified LDL-IC correlate with parameters indicative of cardiovascular and renal disease in diabetic patients and other patient populations. The possibility that spontaneously formed or induced modified LDL antibodies (particularly IgM oxLDL antibodies) may have a protective effect has been suggested, but the data is unclear and needs to be further investigated.

Jupiter to earth: a statin helps people with normal LDL-C and high hs-CRP, but what does it mean?

The JUPITER trial (Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin) (N Engl J Med 2008; 359:2195-2207) compared rosuvastatin (Crestor) 20 mg daily vs placebo in apparently healthy people who had levels of low-density lipoprotein cholesterol (LDL-C) lower than 130 mg/dL but elevated levels (>or= 2 mg/L) of high-sensitivity C-reactive protein (hs-CRP). Rosuvastatin treatment lowered LDL-C levels by 50% and hs-CRP levels by 37%, accompanied by a 44% relative risk reduction in the composite end point of unstable angina, revascularization, and confirmed death from cardiovascular causes. In absolute terms, 95 people had to be treated over 2 years to prevent one event. There was, however, a higher incidence of diabetes in the rosuvastatin group.

Adenoviral expression of human lecithin-cholesterol acyltransferase in nonhuman primates leads to an antiatherogenic lipoprotein phenotype by increasing high-density lipoprotein and lowering low-density lipoprotein

Lecithin-cholesterol acyltransferase (LCAT), a key enzyme in high-density lipoprotein (HDL) metabolism, has been proposed to have atheroprotective properties by promoting reverse cholesterol transport. Overexpression of LCAT in various animal models, however, has led to conflicting results on its overall effect on lipoproteins and atherosclerosis. In this study, the effect of overexpression of LCAT in nonhuman primates on lipoprotein metabolism is examined. Human LCAT was expressed with adenovirus in squirrel monkeys (n = 8), resulting on day 4 in a 22-fold increase of LCAT activity (257 +/- 23 vs 5618 +/- 799 nmol mL(-1) h(-1), P < .0001). At its peak, LCAT was found to nearly double the level of HDL cholesterol from baseline (113 +/- 7 vs 260 +/- 24 mg/dL, P < .01). High-density lipoprotein formed after treatment with the adenovirus was larger in size, as assessed by fast protein liquid chromatography (FPLC) analysis. By kinetic studies, it was determined that there was a decrease in apolipoprotein (Apo) A-I resident time (0.373 +/- 0.027 vs 0.685 +/- 0.045 d(-1), P < .0001) and almost a doubling in the ApoA-I synthetic rate (22 +/- 2 vs 41 +/- 3 mg kg(-1) d(-1), P < .0001), but no overall change in ApoA-I levels. In addition, increased expression of LCAT was associated with a 37% reduction of ApoB levels (12 +/- 1 vs 19 +/- 1 mg/dL, P < .05) due to increased low-density lipoprotein catabolism (fractional catabolic rate = 1.7 +/- 0.1 d(-1) in controls vs 4.2 +/- 0.3 d(-1) in LCAT-treated group, P < .05). In summary, overexpression of LCAT in nonhuman primates leads to an antiatherogenic lipoprotein profile by increasing HDL cholesterol and lowering ApoB, thus making LCAT a potential drug target for reducing atherosclerosis.

Fibrates: where are we now?

Cardiovascular disease remains a leading cause of mortality worldwide. As dyslipidemia increases cardiovascular disease risk, proper management of dyslipidemia is one means by which to decrease cardiovascular disease risk. This review focuses on dyslipidemia treatment utilizing fibrate therapy, which targets high trigylcerides, low HDL, and high small, dense LDL, while contrasting fibrate therapy with statin therapy and combined therapy. Studies were obtained using electronic search strategies, such as Medline and Cochrane Library. Sources selected were limited to those that discussed fibrates, statins, and combined therapy, with specific emphasis placed on sources that focused on fibrates. Selected studies were then assessed for quality via analysis of the study's methodology, results, and data.

RESULTS

of selected studies were then stratified using a rating system devised to determine the quality of results using the scientific evidence provided for them. Combination fibrate and statin therapy can be more effective in achieving optimal lipid levels than just fibrate or statin therapy alone without significant side effects as long as gemfibrozil is not used in therapy.

Statin treatment, carotid atherosclerotic plaque macrophage infiltration and circulating inflammatory markers

BACKGROUND

Statin treatment is considered as first line therapy in patients with atherosclerotic disease. We evaluated the effect of pre-treatment with statins on carotid plaque infiltration by macrophages and on the circulating levels of proinflammatory cytokines in patients who underwent carotid endarterectomy.

PATIENTS AND METHODS

One hundred fourteen patients were enrolled; 89 men and 25 women (mean age 67+/-8 years; range 42-83 years). Fifty three patients (46%) were on statin treatment at least 3 months before endarterectomy and 61 (54%) had never received statin treatment. The serum levels of high sensitivity C reactive protein (hsCRP), serum amyloid A (SAA), tumor necrosis factor alpha (TNFalpha), interleukin (IL)-1beta and IL-6 were evaluated preoperatively. The intensity of macrophage infiltration was evaluated by immunochemistry, using the monoclonal antibody CD 68. The area of the plaque covered by macrophages was measured as a proportion of the whole plaque area, using a custom designed image tool analysis.

RESULTS

Patients on statins had lower serum total cholesterol levels (172+/-50 vs 194+/-35 mg/dl, p= 0.014), lower low density cholesterol levels (103+/-44 vs 123+/-31 mg/dl, p= 0.010) and lower serum hsCRP levels (1.8 [1.1-3.4] vs 3.4 [1.3-4.9] mg/l, p= 0.03), while SAA, TNFalpha, IL-6 and IL-1beta levels did not differ between the 2 groups. The infiltration of atherosclerotic plaque by macrophages was similar in statin treated patients and in controls (0.55+/-0.15% vs 0.49+/-0.19%, p= 0.21).

CONCLUSION

Patients on statins have similar macrophage accumulation in their carotid atherosclerotic plaques compared with patients not on statins. Inflammatory markers were also similar in both groups except for hsCRP which was significantly lower in those taking statins.

Role for protein geranylgeranylation in adult T-cell leukemia cell survival

Adult T-cell leukemia (ATL) is a fatal lymphoproliferative disease that develops in human T-cell leukemia virus type I (HTLV-I)-infected individuals. Despite the accumulating knowledge of the molecular biology of HTLV-I-infected cells, effective therapeutic strategies remain to be established. Recent reports showed that the hydroxyl-3-methylglutaryl (HMG)-CoA reductase inhibitor statins have anti-proliferative and apoptotic effects on certain tumor cells through inhibition of protein prenylation. Here, we report that statins hinder the survival of ATL cells and induce apoptotic cell death. Inhibition of protein geranylgeranylation is responsible for these effects, since simultaneous treatment with isoprenoid precursors, geranylgeranyl pyrophosphate or farnesyl pyrophosphate, but not a cholesterol precursor squalene, restored the viability of ATL cells. Simvastatin inhibited geranylgeranylation of small GTPases Rab5B and Rac1 in ATL cells, and a geranylgeranyl transferase inhibitor GGTI-298 reduced ATL cell viability more efficiently than a farnesyl transferase inhibitor FTI-277. These results not only unveil an important role for protein geranylgeranylation in ATL cell survival, but also implicate therapeutic potentials of statins in the treatment of ATL.

Effect of atorvastatin on hs-CRP in acute coronary syndrome

AIMS

To evaluate the effect of a lower dose (20 mg) of atorvastatin on hs-CRP concentrations in patients with ACS.

METHODS

Group A (n = 50) patients received atorvastatin 20 mg day(-1) for 4 weeks in addition to standard anti-anginal treatment. Group B (n = 50) patients received standard anti-anginal treatment without atorvastatin.

RESULTS

hs-CRP concentrations decreased in both groups, but the decrease was greater in group A. The decrease in hs-CRP was also significantly greater in the subgroups of smoking, hypertension and past history of cardiovascular disease with atorvastatin.

CONCLUSIONS

The use of a lower dose (20 mg) of atorvastatin can offer an attractive approach for early treatment of patients with ACS.

Association of statin therapy with reduced coronary plaque rupture: an optical coherence tomography study

OBJECTIVE

Statin therapy induces plaque regression and may stabilize atheromatous plaques. Optical coherence tomography (OCT) is a high-resolution in-vivo imaging modality that allows characterization of atherosclerotic plaques. We aimed to demonstrate the potential utility of OCT in evaluating coronary plaques in patients with or without statin therapy.

METHODS

Patients undergoing cardiac catheterization were enrolled. We identified culprit lesions and performed intracoronary OCT imaging. Plaque lipid pool, fibrous cap thickness, and frequency of thin-cap fibroatheroma were evaluated using previously validated criteria. Macrophage density was determined from optical signals within fibrous caps. Presence of calcification, thrombosis, and rupture was assessed.

RESULTS

Forty-eight patients were included (26 on statins, 22 without statins). Baseline characteristics were similar apart from lipid profile. Patients on statin therapy had lower total and low-density lipoprotein cholesterol concentrations (4.45+/-1.35 vs. 5.26+/-0.83 mmol/l, P=0.02; 2.23+/-0.78 vs. 3.26+/-0.62 mmol/l, P<0.001, respectively). Frequencies of lipid-rich plaque (69 vs. 82%), thin-cap fibroatheroma (31 vs. 50%), plaque calcification (15 vs. 5%) and thrombosis (15 vs. 32%), and fibrous cap macrophage density were comparable between statin and nonstatin groups (5.9 vs. 6.3%; all P=NS). Ruptured plaques were, however, significantly less frequent in patients on established statin therapy (8 vs. 36%; P=0.03) with a trend toward increased minimum fibrous cap thickness (78 vs. 49 microm; P=0.07).

CONCLUSION

We demonstrated the use of OCT in plaque characterization and found that patients on prior statin therapy have reduced incidence of ruptured plaques and a trend toward thicker fibrous caps. This suggests that statins may stabilize coronary plaques.

Anti-inflammatory agents and antioxidants as a possible "third great wave" in cardiovascular secondary prevention

There are 3 important factors that predispose patients to plaque rupture or recurrent events: plaque burden or multiple arterial plaques, the presence of persistent hyperreactive platelets, and ongoing vascular arterial inflammation. Successful therapeutic strategies focus on these predisposing factors, and the use of low-density lipoprotein-lowering medications (principally statins) and antiplatelet agents (principally aspirin) has had a major impact on the occurrence of cardiovascular outcomes and overall mortality over the last 2 decades. However, despite these interventions, a significant number of patients experience recurrent events or progression of disease. Novel compounds are being studied to determine, for example, whether an increase in high-density lipoprotein will provide additional risk reduction; to date, this has not proved to be sufficiently effective. Although early invasive management has been proved to be superior to medical therapy in patients with plaque rupture producing acute coronary syndromes, its superiority in patients with clinically stable obstructive disease has been questioned. Thus, the search for additional agents to improve the outcomes of patients with atherothrombotic disease continues. The importance of inflammation, a potentially critical element in the initiation, progression, and rupture of plaque, has become increasingly evident. In this supplement, the role of inflammation and its principal cause, oxidative stress, are analyzed as potential targets of pharmacologic therapy. The history of anti-inflammatory and antioxidant therapy in cardiovascular disease is critically examined. Finally, the whole process of contemporary drug discovery and development from lead rationale and identification through biologic screening and testing in animals and then humans is explored, using as an example the xanthophyll carotenoids, a class of potent antioxidants currently under investigation.

Atherogenesis and the humoral immune response to modified lipoproteins

Modified forms of LDL are immunogenic and activate both cell-mediated and humoral immune responses. Both types of responses are pro-inflammatory and are probably primary players in the perpetuation of the chronic inflammatory reaction characteristic of atherosclerosis. The immunologic response to modified LDL can be directed to MHC-II-associated peptides in the case of T helper cells, and to a variety of epitopes-modified lysine groups, modified phospholipids, proteins that become associated with oxidized LDL (such as beta2GP1)--in the case of B cell responses. T cell activation is likely to play a major role through cross-activation of macrophages. Humoral responses to modified LDL are pathogenic as a consequence of the formation of antigen-antibody complexes containing modified LDL and IgG antibodies. Those immune complexes induce cholesterol ester accumulation in macrophages and macrophage-like cells, and induce the release of pro-inflammatory cytokines, chemokines, oxygen active radicals, and matrix metalloproteinases from those cells. There is no conclusive evidence supporting a protective role for IgM antibodies in humans, possibly because autoantibodies to modified lipoproteins are predominantly of the IgG isotype.

Evolution of anticoagulant and antiplatelet therapy: benefits and risks of contemporary pharmacologic agents and their implications for myonecrosis and bleeding in percutaneous coronary intervention

Periprocedural myonecrosis, as evidenced by elevated creatine kinase-myocardial bound (CK-MB) levels, occurs in up to 25% of patients undergoing percutaneous coronary intervention (PCI) and has been linked with an increased risk of adverse short- and long-term clinical outcomes. Such myonecrosis arises from three main pathophysiological mechanisms: procedure-related complications, lesion-specific characteristics (e.g., large thrombus burden, plaque volume), and patient-specific characteristics (e.g., genetic predisposition, arterial inflammation). Periprocedural myonecrosis has not been definitively identified as the cause of postprocedural ischemic events, although agents that reduce or prevent thrombosis--including aspirin, thienopyridines, heparin, low-molecular-weight heparins, glycoprotein IIb/IIIa inhibitors, and direct thrombin inhibitors--have been shown to reduce the incidence of ischemic outcomes in this population, as have agents that reduce inflammation (aspirin, statins). At the same time, antithrombotic agents are known to increase the risk of bleeding and the use of transfusions, which have likewise been associated with worse outcomes in these patients. Thus, optimal management of patients undergoing PCI represents a balance between minimizing the risk of ischemic outcomes and simultaneously minimizing the risk of major bleeding. It may be that patients who have only minor, untreated postprocedural elevations in CK-MB level (with no clinical or angiographic signs of ischemia) might have a better prognosis than patients who have normal CK-MB levels but who suffer major bleeding complications.

A peri-operative statin update for non-cardiac surgery. Part II: Statin therapy for vascular surgery and peri-operative statin trial design

This is the second of two review articles evaluating peri-operative statin therapy. In surgical patients, the utility of peri-operative statin therapy is strongly suggested by retrospective studies, although it is probably overestimated, as important confounding factors have not been controlled for and hence the literature is considered to be currently inconclusive. This review examines the potential mechanisms and indications for peri-operative statin protection, the efficacy of acute peri-operative beta-blockade in addition to statin therapy, the effect of peri-operative statin therapy withdrawal and the implications of comorbidities associated with peri-operative cardiovascular risk on statin therapy. Recommendations concerning appropriate dosing, duration, therapeutic targets and necessary investigations when prescribing peri-operative statins are made. Peri-operative study design recommendations are suggested, so that future meta-analyses may be more informative. Recommendations are made regarding retrospective reporting of statin studies to minimise the bias inherent in a number of the current retrospective studies on this subject.

Statin therapy for stroke prevention

BACKGROUND AND PURPOSE

Statins are widely used to reduce the risk of stroke in patients with coronary artery disease (CAD), but less so in patients without CAD. We reviewed recent trials for new evidence for the reduction in risk of stroke.

SUMMARY OF REVIEW

In patients with CAD, moderate-intensity statin treatment has been associated with reductions in risk of stroke, with no increase in hemorrhagic stroke. Additionally, in the TNT trial, intensive lipid lowering provided further stroke risk reduction compared with moderate lipid lowering in patients with stable CAD. Evidence is now available that statin therapy also reduces stroke risk in patients without CAD but at high cardiovascular risk, or with diabetes mellitus. The SPARCL trial showed that intensive statin therapy started within 6 months after a cerebrovascular event significantly reduced stroke risk and stroke severity. Low cholesterol levels have been associated with increased risk of hemorrhagic stroke, but although an increased risk of hemorrhagic stroke was observed in patients with prior hemorrhagic stroke in SPARCL, this was not related to low-density lipoprotein cholesterol levels. Clinical trials have recruited few patients with both coronary and cerebrovascular disease, but these patients are also expected to experience significant cardiovascular benefit with statin therapy.

CONCLUSIONS

Trial data show that statins reduce the risk of stroke, in addition to providing cardiovascular benefits. Consequently, physicians should consider statin therapy in all patients at high risk of stroke.

Substituted pyrazoles as hepatoselective HMG-CoA reductase inhibitors: discovery of (3R,5R)-7-[2-(4-fluoro-phenyl)-4-isopropyl-5-(4-methyl-benzylcarbamoyl)-2H-pyrazol-3-yl]-3,5-dihydroxyheptanoic acid (PF-3052334) as a candidate for the treatment of hypercholesterolemia

In light of accumulating evidence that aggressive LDL-lowering therapy may offer increased protection against coronary heart disease, we undertook the design and synthesis of a novel series of HMG-CoA reductase inhibitors based upon a substituted pyrazole template. Optimizing this series using both structure-based design and molecular property considerations afforded a class of highly efficacious and hepatoselective inhibitors resulting in the identification of (3 R,5 R)-7-[2-(4-fluoro-phenyl)-4-isopropyl-5-(4-methyl-benzylcarbamoyl)-2 H-pyrazol-3-yl]-3,5-dihydroxy-heptanoic (PF-3052334) as a candidate for the treatment of hypercholesterolemia.

Meta-analysis of the role of statin therapy in reducing myocardial infarction following elective percutaneous coronary intervention

Statin medications initiated during percutaneous coronary intervention have been evaluated in clinical trials mainly to assess if this therapy reduces subsequent restenosis. The benefit of statin therapy on individual cardiovascular outcomes other than restenosis is largely unknown. Hence, a meta-analysis of the available randomized trials was conducted to evaluate individual cardiovascular outcomes with statin therapy compared with placebo after elective percutaneous coronary intervention. In all, there were 6 studies available for analysis (Prevention of Restenosis by Elisor After Transluminal Coronary Angioplasty [PREDICT], Fluvastatin Angioplasty Restenosis [FLARE], the Lescol Intervention Prevention Study [LIPS], German Atorvastatin Intravascular Ultrasound [GAIN], Atorvastatin for Reduction of Myocardial Damage During Angioplasty [ARMYDA], and a study by Briguori et al) that randomized 3,941 patients (1,967 to statins and 1,974 to placebos). Clinical follow-up ranged from 1 day to 45 months. The incidence of myocardial infarction was 3.0% in the statin group and 5.2% in the placebo group (odds ratio [OR] 0.57, 95% confidence interval [CI] 0.42 to 0.78, p<0.0001). The incidence of all-cause mortality was 2.3% versus 3.0% (OR 0.74, 95% CI 0.50 to 1.1, p=0.14), that of cardiovascular mortality was 0.71% versus 1.2% (OR 0.58, 95% CI 0.30 to 1.11, p=0.10), and that of repeat surgical or percutaneous revascularization was 19.6% versus 21.9% (OR 0.89, 95% CI 0.78 to 1.02, p=0.098) in the statin arm versus the placebo arm, respectively. The incidence of stroke was 0.4% in the statin arm and 0.08% in the placebo arm (OR 3.00, 95% CI 0.60 to 14.77, p=0.18). In conclusion, statin therapy initiated at the time of elective percutaneous coronary intervention significantly reduces myocardial infarction.

Statins and C-reactive protein levels

In patients with or at risk for cardiovascular disease (CVD), including hypertensive individuals, lowering levels of low-density lipoprotein cholesterol (LDL-C) reduces CVD risk. Statins are the most effective of available therapies for lowering LDL-C. Extensive clinical trial data have shown that the degree of LDL-C reduction obtained depends on the particular statin used and that intensive LDL-C lowering reduces the incidence of cardiovascular events compared with more moderate LDL-C lowering. More recent data suggest that effects independent of LDL-C lowering may also play a part in the reduction in cardiovascular events. C-reactive protein (CRP), a marker of inflammation, is a potential predictor of CVD risk, and statins reduce CRP levels by up to 60%. CRP reduction is independent of LDL-C lowering, and variation between statins in CRP reduction may play some role in CVD event reduction rates. At present, however, there are few outcome data relating to the cardiovascular benefits of reducing CRP.

Design and synthesis of hepatoselective, pyrrole-based HMG-CoA reductase inhibitors

This manuscript describes the design and synthesis of a series of pyrrole-based inhibitors of HMG-CoA reductase for the treatment of hypercholesterolemia. Analogs were optimized using structure-based design and physical property considerations resulting in the identification of 44, a hepatoselective HMG-CoA reductase inhibitor with excellent acute and chronic efficacy in a pre-clinical animal models.