Effects of long-term treatment with lovastatin on the clotting system and blood platelets

Platelet function and activation markers in primary hypercholesterolemia treated with anti-PCSK9 monoclonal antibody: A 12-month follow-up

BACKGROUND AND AIMS

In the association between hypercholesterolemia (HC) and thrombotic risk platelet hyper-reactivity plays an important role. The inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) to reduce plasma LDL-cholesterol merges as effective therapeutic strategy to prevent cardiovascular (CV) events. Aim of this study was to verify whether a treatment up to 12 months with the monoclonal antibodies (mAbs) anti-PCSK9 influences platelet function in primary HC.

METHODS AND RESULTS

In patients affected by primary HC (n = 24), all on background of statin and 17 on acetyl salicylic acid (ASA), platelet function parameters were evaluated at baseline up to 12 months of treatment with the mAb anti-PCSK9 alirocumab or evolocumab. From baseline, the treatment with anti-PCSK9 mAbs: i) in ASA HC patients, significantly decreased platelet aggregation detected in platelet-rich plasma by light transmission aggregometry and in whole blood Platelet Function Analyzer-100 assay; ii) in all HC patients, significantly decreased platelet membrane expression of CD62P and plasma levels of the in vivo platelet activation markers soluble CD40 Ligand, Platelet Factor-4, and soluble P-Selectin. Furthermore, CD62P expression, and sP-Selectin, PF-4, sCD40L levels significantly correlated with serum PCSK9.

CONCLUSION

Besides markedly lowering LDL-c levels, our results suggest that HC patients benefit from anti-PCSK9 mAb treatment also for reducing platelet reactivity and increasing platelet sensitivity to the inhibitory effects of aspirin. These effects on platelets could play a role in the reduction of CV event incidence in patients treated with PCSK9 inhibitors.

High-dose statin therapy and risk of intracerebral hemorrhage: a meta-analysis

Statin plays a major role in the primary and secondary prevention of cardiovascular disease (CVD). Inconsistent findings in the studies have been observed toward the risk of intracerebral hemorrhage (ICH) using higher dose of statin. To examine this issue, we performed a meta-analysis of randomized controlled trials (RCTs) to assess the association between higher dose of various statins and risk of ICH among patients with CVD. Literature was searched for studies published before June 10, 2015, using electronic database 'PubMed', 'EMBASE', and 'Google Scholar' as well as from many trial databases. The following search terms were used: 'Statin therapy' AND 'Cardiovascular Disease', AND 'Dose' AND 'Intracerebral hemorrhage', AND 'Randomized Controlled Trials' AND 'High Dose Statin'. High dose of statins was defined as atorvastatin 80 mg, simvastatin 80 mg, pravastatin 40 mg, rosuvastatin 20 mg per day. Fixed-effect model was used to estimate the risk ratio (RR) and 95% confidence interval (CI) if heterogeneity was <50%; otherwise, random-effect model was used. Begg's funnel plot was used to assess the publication bias. Seven RCTs involving 31,099 subjects receiving high-dose statin and 31,105 subjects receiving placebo were analyzed in our meta-analysis. A significant risk of ICH was observed in subjects with higher dose of statin (RR = 1.53; 95% CI: 1.16-2.01; P = 0.002). There was no difference in all-cause mortality between the two groups (RR = 0.95; 95% CI: 0.86-1.06; P = 0.36). No publication bias was observed through Begg's funnel plot. Higher dose of statins was found to be associated with the risk of ICH. Future studies are needed to confirm these findings.

Statin Therapy May not Effect NLR and MPV Levels in Patients With Hypercholesterolemia: A Retrospective Study

Statins may exert pleiotropic effects in coronary artery disease (CAD), diabetes mellitus, and familial hypercholesterolemia. We evaluated the effects of statins on the neutrophil-lymphocyte ratio (NLR) and mean platelet volume (MPV) in 261 consecutive patients with hypercholesterolemia having CAD or at high cardiovascular (CV) risk and 50 healthy participants who were retrospectively included in this study. Patients were treated with 10 to 80 mg atorvastatin or 10 to 40 mg rosuvastatin for 24 weeks according to baseline levels of cholesterol, triglycerides, and CV risk. Baseline NLR and MPV were significantly higher in patients with CAD or at high risk compared to the control group (1.89 [0.37-6.78]) vs 1.44 [0.75-2.41], P < .001 and 8.8 [6.27-18.6] vs 8.45 [6-11] fL, P = .038, respectively). The NLR, MPV, and lipid parameters were also compared in the patient group after statin treatment for 24 weeks. Lipid levels decreased but the NLR and MPV did not change significantly after the statin therapy. Further studies are needed to clarify the effect of statin therapy on NLR and MPV in patients with CAD or at high CV risk.

Influence of blood lipids on global coagulation test results

Background

High levels of blood lipids have been associated with high levels of coagulation factors. We investigated whether blood lipids influence the results of global coagulation tests, including prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin generation assay (TGA).

Methods

PT, aPTT, and TGA, along with procoagulant and anticoagulant factors, were measured in 488 normal individuals. Vitamin K status was assessed with prothrombin-induced by vitamin K absence-II (PIVKA-II).

Results

The procoagulant factors II, VII, IX, X, and XI and anticoagulant factors protein C and protein S showed significant correlations with triglyceride, and the procoagulant factors II, V, VII, IX, X, XI, and XII and anticoagulant factors antithrombin and protein C correlated with total cholesterol. There were no correlations of blood lipid levels with PIVKA-II levels. Subjects with high triglyceride levels (≥200 mg/dL) showed shorter PT values than those with lower triglyceride levels. However, aPTT value was not changed in terms of blood lipid levels. In both 1 and 5 pM tissue factor-induced TGAs, subjects in the high-triglyceride or high-cholesterol groups (≥240 mg/dL) had high levels of lag time, time-to-peak, and endogenous thrombin potential. Total cholesterol was a significant determinant of PT and TGA values.

Conclusion

High blood lipids were related with increased coagulation activity in a normal population. Our findings are expected to help interpret the global coagulation test results in individuals with high lipid levels.

Clinical review: Statins and trauma--a systematic review

Statins, in addition to their lipid-lowering properties, have anti-inflammatory actions. The aim of this review is to evaluate the effect of pre-injury statin use, and statin treatment following injury. MEDLINE, EMBASE, and CENTRAL databases were searched to January 2012 for randomised and observational studies of statins in trauma patients in general, and in patients who have suffered traumatic brain injury, burns, and fractures. Of 985 identified citations, 7 (4 observational studies and 3 randomised controlled trials (RCTs)) met the inclusion criteria. Two studies (both observational) were concerned with trauma patients in general, two with patients who had suffered traumatic brain injury (one observational, one RCT), two with burns patients (one observational, one RCT), and one with fracture healing (RCT). Two of the RCTs relied on surrogate outcome measures. The observational studies were deemed to be at high risk of confounding, and the RCTs at high risk of bias. Three of the observational studies suggested improvements in a number of clinical outcomes in patients taking statins prior to injury (mortality, infection, and septic shock in burns patients; mortality in trauma patients in general; mortality in brain injured patients) whereas one, also of trauma patients in general, showed no difference in mortality or infection, and an increased risk of multi-organ failure. Two of three RCTs on statin treatment in burns patients and brain injured patients showed improvements in E-selectin levels and cognitive function. The third, of patients with radial fractures, showed no acceleration in fracture union. In conclusion, there is some evidence that pre-injury statin use and post-injury statin treatment may have a beneficial effect in patients who have suffered general trauma, traumatic brain injury, and burns. However, these studies are at high risk of confounding and bias, and should be regarded as 'hypothesisgenerating'. A well-designed RCT is required to determine the therapeutic efficacy in improving outcomes in this patient population.

Statin therapy in the reduction of cardiovascular events in patients undergoing intermediate-risk noncardiac, nonvascular surgery

BACKGROUND

Hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) reduce perioperative cardiac events in high-risk patients undergoing cardiovascular surgery. However, there is paucity of data on the role of statins in patients undergoing intermediate-risk noncardiac, nonvascular surgery (NCNVS).

HYPOTHESIS

Statins are cardioprotective in intermediate-risk NCNVS.

METHODS

We identified a retrospective cohort of patients undergoing intermediate risk NCNVS. Our composite end point (CEP) included 30-day all-cause mortality, atrial fibrillation (AF), and nonfatal myocardial infarction (MI). A stepwise logistic regression with adjustment using propensity scores was performed to determine if statin therapy was independently associated with the risk reduction of adverse postoperative cardiovascular outcomes.

RESULTS

We identified 752 patients. Seventy-five of them (9.97%) developed composite end points; 10 (1.33%) had in-hospital nonfatal MI, 44 (5.85%) developed AF, and 35 (4.65%) died within 30 days. The 30-day all-cause mortality was 31/478 (6.48%) among statin nonusers vs 4/274 (1.45%) for statin users (P < 0.002). As compared with nonusers, patients on statin therapy had a 5-fold reduced risk of 30-day all-cause mortality. Statin therapy was associated with decreased CEP after adjusting for baseline characteristics, with a propensity score to predict use of statins (odds ratio [OR]: 0.54, 95% confidence interval [CI]: 0.30-0.97, P = 0.039). After further adjustment for propensity score, diabetes mellitus, percutaneous coronary intervention, and prior coronary artery bypass grafting, statin therapy proved beneficial (OR: 0.51, 95% CI: 0.28-0.92, P = 0.026).

CONCLUSIONS

Statin use in the perioperative period was associated with a reduction in cardiovascular adverse events and 30-day all-cause mortality in patients undergoing intermediate-risk NCNVS.

Cardioprotective and antihypertensive effects of Enicostemma littorale Blume extract in fructose-fed rats

We investigated the protective effects of Enicostemma littorale Blume (EL) extract on hypertension and insulin resistance along with its associated cardiovascular complications in high fructose (HF) fed rats. For this, rats were divided among 4 groups: (i) control, fed laboratory chow; (ii) fed with a high level of fructose; (iii) fed with a high level of fructose plus E. littorale extract; and (iv) fed with a high level of fructose plus rosiglitazone (Rg). EL and Rg treatments were given simultaneously with HF diet. The results show that untreated HF-fed rats showed altered oral glucose tolerance, increased fasting insulin, and increased fasting glucose. These rats also exhibited hypertriglyceridemia, moderate hypertension, platelet hyperaggregability, decreased prothrombin time, activated partial thromboplastin time, altered vascular reactivity, and increased serum levels of enzymes (creatine kinase, type muscle-brain (CK-MB), aspartate aminotransferase (SGOT), lactate dehydrogenase (LDH), and alanine aminotransferase (SGPT). This is the first demonstration of platelet hyperaggregation and prothrombotic alteration in HF-fed rats. HF-fed rats treated with EL showed improved insulin resistance, along with reduced hypertriglyceridemia, hypertension, platelet aggregability, blood coagulation, serum enzymes (CK-MB, SGOT, LDH and SGPT), and vascular reactivity. These effects of EL in HF-induced hypertensive rats might be associated with the suppression of hyperinsulinemia and hypertriglyceridemia, along with its antiatherogenic and antithrombogenic potential. These data indicate that the aqueous extract of EL has great therapeutic potential for the prevention and (or) management of insulin resistance and the associated hypertension.

The effect of a platelet cholesterol modulation on the acetylsalicylic acid-mediated blood platelet inhibition in hypercholesterolemic patients

Aspirin (acetylsalicylic acid, ASA) is widely used in the prevention of cardiovascular disease, but its beneficial effects may be restrained in some individuals, where the reduced ability of ASA to protect against arterial thrombotic events is observed. We analyzed the influence of the treatment with atorvastatin (10mg/day) on the platelet sensitivity to ASA monitored under in vitro conditions in hypercholesterolemic patients. The associations between plasma or platelet cholesterol parameters and the ASA-mediated inhibition of platelet reactivity or the extent of platelet protein acetylation by ASA were estimated in the patients treated with atorvastatin for 1, 3, or 6 months. Out of 27 patients, in 17 individuals platelets appeared significantly more sensitive to 50 μM ASA in arachidonic acid- or collagen-induced whole blood aggregation following 1 month atorvastatin therapy (inhibition by 60.9 ± 5.6% vs. 48.8 ± 5.4%, P<0.05 for 0.5mM arachidonic acid, 40.8 ± 2.9% vs. 27.0 ± 4.1%, P<0.05 for 1 μg/ml collagen), and this effect lasted for 3 and 6 months, remaining in a weak, although significant, relation to the reduction of platelet cholesterol content (R(S)=-0.277, P<0.002 for arachidonic acid, R(S)=-0.197, P<0.02 for collagen). It was, however, not dependent upon either antiplatelet action or plasma lipid-lowering activity of atorvastatin. In addition, in about 50% of patients, we noticed that ASA (50 μM) significantly and time-dependently diminished thromboxane B(2) concentration in atorvastatin-treated patients. The ASA-induced acetylation of platelet proteins significantly increased in the course of atorvastatin therapy and was associated with reduced platelet cholesterol (R(S)=-0.598, P<0.0001). In conclusion, statin therapy may improve platelet sensitivity to ASA in some hypercholesterolemic patients. This effect may extend beyond the action of atorvastatin as merely a lipid-lowering agent. The mechanisms of resistance of some patients to such a combined ASA-statin treatment remain to be elucidated.

Statin use following intracerebral hemorrhage: a decision analysis

CONTEXT

Statins are widely prescribed for primary and secondary prevention of ischemic cardiac and cerebrovascular disease. Although serious adverse effects are uncommon, results from a recent clinical trial suggested increased risk of intracerebral hemorrhage (ICH) associated with statin use. For patients with baseline elevated risk of ICH, it is not known whether this potential adverse effect offsets the cardiovascular and cerebrovascular benefits.

OBJECTIVE

To address the following clinical question: Given a history of prior ICH, should statin therapy be avoided?

DESIGN

A Markov decision model was used to evaluate the risks and benefits of statin therapy in patients with prior ICH.

MAIN OUTCOME MEASURE

Life expectancy, measured as quality-adjusted life-years. We investigated how statin use affects this outcome measure while varying a range of clinical parameters, including hemorrhage location (deep vs lobar), ischemic cardiac and cerebrovascular risks, and magnitude of ICH risk associated with statins.

RESULTS

Avoiding statins was favored over a wide range of values for many clinical parameters, particularly in survivors of lobar ICH who are at highest risk of ICH recurrence. In survivors of lobar ICH without prior cardiovascular events, avoiding statins yielded a life expectancy gain of 2.2 quality-adjusted life-years compared with statin use. This net benefit persisted even at the lower 95% confidence interval of the relative risk of statin-associated ICH. In patients with lobar ICH who had prior cardiovascular events, the annual recurrence risk of myocardial infarction would have to exceed 90% to favor statin therapy. Avoiding statin therapy was also favored, although by a smaller margin, in both primary and secondary prevention settings for survivors of deep ICH.

CONCLUSIONS

Avoiding statins should be considered for patients with a history of ICH, particularly those cases with a lobar location.

Basic Science Review Section: Statin Therapy—Part II: Clinical Considerations for Cardiovascular Disease

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, commonly known as statins, are the medical treatment of choice for hypercholesterolemia. In addition to achieving a therapeutic decrease in serum cholesterol levels, statin therapy appears to promote pleiotropic effects that are independent of changes in serum cholesterol. These cholesterol lowering and pleiotropic effects are beneficial not only for the coronary circulation, but for the myocardium and peripheral arterial system as well. Patients receiving statin therapy must be carefully monitored, however, as statins potentially have harmful side effects and drug interactions. This article is part II of a 2-part review, and it focuses on the clinical aspects of statin therapy in cardiovascular disease.

A combination of proteasome inhibitors and antibiotics prevents lethality in a septic shock model

Our recent studies with lactacystin, a prototype proteasome inhibitor, have suggested that the proteasome is a key regulator of LPS-induced signaling pathways contributing to the inflammatory process. Moreover, lactacystin protects animals from LPS-induced shock. Therefore, we sought to identify other less toxic compounds that would block the chymotrypsin-like activity of the proteasome or LPS-induced nitric oxide (NO). After screening over 100 natural compounds (based on chemistry and inhibition of LPS-induced biological activities), we now report for the first time that quercetin, like lactacystin (the prototype proteasome inhibitor), and mevinolin are also inhibitors of the chymotrypsin-like activity of the cellular proteasome within living cells. In addition, this study also suggests that mevinolin and quercetin both have relatively potent anti-inflammatory effects on LPS-treated macrophages in vitro. Interestingly, both of these compounds behave like lactacystin in that they block LPS-induced NO to a greater extent than TNF-alpha. The results of our experiments clearly suggest that mevinolin, in combination with the antibiotic imipenem, can provide protection against polymicrobial septic lethality induced by cecal-ligation and puncture in mice. Collectively, these studies strongly support the conclusion that therapeutic targeting of cellular proteasomes, in conjunction with standard antimicrobial therapy, may be of considerable survival benefit in the treatment of septic shock.

Atorvastatin is a promising partner for antimalarial drugs in treatment of Plasmodium falciparum malaria

Atorvastatin (AVA) is a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor. AVA exposure resulted in the reduced in vitro growth of 22 Plasmodium falciparum strains, with the 50% inhibitory concentrations (IC(50)s) ranging from 2.5 microM to 10.8 microM. A significant positive correlation was found between the strains' responses to AVA and mefloquine (r = 0.553; P = 0.008). We found no correlation between the responses to AVA and to chloroquine, quinine, monodesethylamodiaquine, lumefantrine, dihydroartemisinin, atovaquone, or doxycycline. These data could suggest that the mechanism of AVA uptake and/or the mode of action of AVA is different from those for other antimalarial drugs. The IC(50)s for AVA were unrelated to the occurrence of mutations in the transport protein genes involved in quinoline antimalarial drug resistance, such as the P. falciparum crt, mdr1, mrp, and nhe-1 genes. Therefore, AVA can be ruled out as a substrate for the transport proteins (CRT, Pgh1, and MRP) and is not subject to the pH modification induced by the P. falciparum NHE-1 protein. The absence of in vitro cross-resistance between AVA and chloroquine, quinine, mefloquine, monodesethylamodiaquine, lumefantrine, dihydroartemisinin, atovaquone, and doxycycline argues that these antimalarial drugs could potentially be paired with AVA as a treatment for malaria. In conclusion, the present observations suggest that AVA is a good candidate for further studies on the use of statins in association with drugs known to have activities against the malaria parasite.

Prior statin use, intracranial hemorrhage, and outcome after intra-arterial thrombolysis for acute ischemic stroke

BACKGROUND AND PURPOSE

There are only limited data on whether prior statin use and/or cholesterol levels are associated with intracranial hemorrhage (ICH) and outcome after intra-arterial thrombolysis. The purpose of this study was to evaluate the association of statin pretreatment and cholesterol levels with the overall frequency of ICH, the frequency of symptomatic ICH, and clinical outcome at 3 months.

METHODS

We analyzed 311 consecutive patients (mean age, 63 years; 43% women) who received intra-arterial thrombolysis.

RESULTS

Statin pretreatment was present in 18%. The frequency of any ICH was 20.6% and of symptomatic ICH 4.8%. Patients with any ICH were more often taking statins (30% versus 15%, P=0.005), more often had atrial fibrillation (45% versus 30%, P=0.016), had more severe strokes (mean National Institute of Health Stroke Scale score 16.5 versus 14.7, P=0.022), and less often good collaterals (16% versus 24%, P=0.001). Patients with symptomatic ICH were more often taking statins (40% versus 15%, P=0.009) and had less often good collaterals (0% versus 24%, P<0.001). Any ICH or symptomatic ICH were not associated with cholesterol levels. After multivariate analysis, the frequency of any ICH remained independently associated with previous statin use (OR, 3.1; 95% CI, 1.53 to 6.39; P=0.004), atrial fibrillation (OR, 2.5; CI, 1.35 to 4.75; P=0.004), National Institutes of Health Stroke Scale score (OR, 1.1; CI, 1.00 to 1.10; P=0.037), and worse collaterals (OR, 1.7; CI, 1.19 to 2.42; P=0.004). There was no association of outcome with prior statin use, total cholesterol level, or low-density lipoprotein cholesterol level.

CONCLUSIONS

Prior statin use, but not cholesterol levels on admission, is associated with a higher frequency of any ICH after intra-arterial thrombolysis without impact on outcome.

Statins and sepsis

Severe sepsis and septic shock is common and frequently fatal. Over the last few years, the primary treatments demonstrated to improve outcome from several major clinical trials have finally emerged. However, translating these recent therapeutic advances to routine clinical practice has proven controversial, and new approaches of additional strategies are continued to be developed. Given their pleiotropic effects related to many pathophysiological determinants of sepsis, statin therapy could be the next step in the search for adjuvant therapy. A future challenge may be to test both the efficacy and the safety by large randomized controlled clinical trials ascertaining the effects of statins administered at the onset of sepsis and in patients with severe sepsis or septic shock admitted into intensive care units.

Enhanced nitric oxide and cyclic GMP formation plays a role in the anti-platelet activity of simvastatin

BACKGROUND AND PURPOSE

It has been found that 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) exert various vascular protective effects, beyond their cholesterol-lowering property, including inhibition of platelet-dependent thrombus formation. The objective of the present study was to determine whether the nitric oxide (NO)/cyclic GMP-mediated processes in platelets contribute to the anti-aggregatory activity of simvastatin.

EXPERIMENTAL APPROACH

After rabbit platelets were incubated with simvastatin for 5 min, aggregation was induced and the platelet aggregation, nitric oxide synthase activity, guanylyl cyclase activity, NO and cyclic GMP formation were measured appropriately.

KEY RESULTS

Treatment with simvastatin concentration-dependently inhibited platelet aggregation induced by collagen or arachidonic acid with an IC(50) range of 52-158 microM. We also demonstrated that simvastatin (20-80 microM) concentration-dependently further enhanced collagen-induced NO and cyclic GMP formation through increasing NOS activity (from 2.64+/-0.12 to 3.52+/-0.21-5.10+/-0.14 micromol min(-1) mg protein(-1)) and guanylyl cyclase activity (from 142.9+/-7.2 to 163.5+/-17.5-283.8+/-19.5 pmol min(-1) mg protein(-1)) in the platelets. On the contrary, inhibition of platelet aggregation by simvastatin was markedly attenuated (by about 50%) by addition of a nitric oxide synthase inhibitor, a NO scavenger or a NO-sensitive guanylyl cyclase inhibitor. The anti-aggregatory effects of simvastatin were significantly increased by addition of a selective inhibitor of cyclic GMP phosphodiesterase.

CONCLUSIONS AND IMPLICATIONS

Our findings indicate that enhancement of a NO/cyclic GMP-mediated process plays an important role in the anti-aggregatory activity of simvastatin.

Reinforcing a continuum of care: in-hospital initiation of long-term secondary prevention following acute coronary syndromes

INTRODUCTION

Patients with a history of acute coronary syndrome are particularly susceptible to further vascular or ischemic events. Effective secondary prevention following acute coronary syndrome requires multiple medications targeting the different mechanisms of atherothrombosis. The 2002 American College of Cardiology/American Heart Association guidelines for the management of unstable angina and non ST-segment myocardial infarction and the 2004 guidelines for ST-segment myocardial infarction assign priority to the long-term administration of four critical classes of drugs: antiplatelet agents, in particular aspirin and clopidogrel, beta-blockers, angiotensin-converting enzyme inhibitors, and statins.

CONCLUSIONS

Despite clinical trial evidence demonstrating their ability to reduce cardiovascular morbidity and mortality, available preventive pharmacotherapies remain underutilized. Suboptimal compliance with current recommendations, as with other management guidelines, arises from a host of entrenched physician, patient, and system-related factors. Optimal management of acute coronary syndrome acknowledges a continuum of care in which acute stabilization represents a single important component. Early, in-hospital implementation of secondary preventive measures reinforces the continuum of care approach, promoting a successful transition from treatment to prevention, inpatient to outpatient management, and, when appropriate, subspecialist to generalist care.

Statins: An essential component in the management of carotid artery disease

OBJECTIVE

We aimed to define the role of treatment using statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) in the management of patients with carotid artery disease.

LITERATURE SEARCH METHODS

We searched PubMed for studies evaluating the effect of statins on carotid IMT and the occurrence of cerebrovascular events.

LITERATURE SEARCH RESULTS

Current evidence indicates that routine statin therapy reduces carotid intima-media thickness progression and stroke risk. Additionally, statin treatment significantly reduces perioperative as well as long-term morbidity and mortality in patients undergoing carotid surgery or endovascular interventions. It would also be expected that statins would reduce coronary events in this high-risk population.

CONCLUSIONS

Statins should be considered as an essential component of the therapeutic approach of patients with carotid artery stenosis.

Statins and stroke prevention

Over the past decade, statins have been proven to significantly decrease coronary events in primary and secondary prevention of coronary artery disease. Recent clinical trials have indicated that statins significantly reduce stroke risk in patients with vascular disease. The Cholesterol Treatment Trialists' Collaborators in a meta-analysis including 90,056 patients found that the use of statins determined a significant 17% proportional reduction in the incidence of first-ever stroke of any type per 1 mmol/l low-density lipoprotein (LDL) cholesterol reduction. During an average of 5 years of treatment, the reduction in the overall incidence of stroke was about one sixth per 1 mmol/l LDL cholesterol decrease meaning that 8 fewer participants have any stroke per 1,000 among those with preexisting coronary artery disease at baseline, compared with 5 fewer per 1,000 among the participants with no such history. It is not known whether these findings might be due to the cholesterol reduction effect of statins or to pleiotropic effects of statins, such as improved endothelial function, decreased platelet aggregability, and reduced vascular inflammation. In secondary prevention of stroke, the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) study found that treatment with atorvastatin reduced the risk of recurrent cerebrovascular events in patients with recent stroke or transient ischemic attack but no history of heart disease. Combining the results of patients with no history of heart disease from the SPARCL study and Heart Protection Study in a mini meta-analysis, compared with placebo, statins were associated with a barely nonsignificant difference in recurrent stroke (OR = 0.87, 95% CI = 0.75-1.01, p = 0.07) and a significant difference in the occurrence of major vascular events (OR = 0.78, 95% CI = 0.68-0.88, p = 0.0001) at final follow-up.

Statins and blood pressure: is there an effect or not?

In addition to the lipid-lowering effects of statins, several basic and clinical studies in recent years have examined the effects of these agents on other cardiovascular parameters. Some of these studies investigated the general impact of a statin on blood pressure (BP) among various other factors, while others were specifically designed to determine this effect. Data from animal studies are conflicting but the majority of human studies in the field report a beneficial effect, and most available statin compounds are reported to lower BP levels. Recent clinical studies using ambulatory BP measurements support these findings. Although the exact actions of statins involved in this effect are unknown, several possible mechanisms can be hypothesized. This review summarizes existing data on the effect of statins on BP, aiming to give an overview of the current knowledge and to provide perspectives for future research in the field.

Effects of atorvastatin and aspirin combined therapy on inflammatory responses in patients undergoing coronary artery bypass grafting

This study was conducted to compare the effects of atorvastatin plus aspirin combined therapy on inflammatory responses, endothelial cell function, and blood coagulation system in patients undergoing coronary artery bypass grafting (CABG) to aspirin monotherapy. The patients were randomized into atorvastatin plus aspirin combined therapy group and aspirin monotherapy group. Reduced total cholesterol in the combined therapy group was found in a short term of medication for 14 days. On postoperative day (POD)-14, inhibitory effects of the combined therapy on whole blood aggregation as well as platelet activation assessed by flow cytometry were stronger than those of the monotherapy. Furthermore, cytokine, cytokine receptors, c-reactive protein and alpha1-acid glycoprotein in the combined therapy group were down-regulated on POD-14. At the same time, circulating levels of thromboxane A(2), vascular endothelial growth factor and thrombin-antithrombin III complex as well as P-selectin, L-selectin and intercellular adhesion molecule-1 were down-regulated, while E-selectin and transforming growth factor-beta1 was up-regulated. Atorvastatin plus aspirin combined therapy may improve inflammatory responses, accelerated platelet function, vascular endothelial cell function, blood coagulation system at the early stage such as 14th day after CABG. In conclusion, atorvastatin and aspirin combined therapy may bring beneficial effects to the patient after CABG.

Statins: panacea for sepsis?

Sepsis occurs when the immune system responds to a localised infection at a systemic level, thereby causing tissue damage and organ dysfunction. Statins have proven health benefits in many diseases involving vascular inflammation and injury. Recent animal data suggest that the administration of a statin before a sepsis-inducing insult reduces morbidity and improves survival. The immunomodulatory and anti-inflammatory effects of statins, collectively referred to as pleiotropic effects, lend biological plausibility to such findings. Limited human data hint at reduced mortality rates in bacteraemic patients, and a reduced risk of sepsis in patients with bacterial infections concurrently taking statins. These lines of evidence point to a potential new treatment and prevention modality for sepsis. The stage is set for randomised controlled clinical trials that will determine whether statins represent a safe and beneficial treatment in critically ill, septic patients and whether statins are effective at preventing sepsis in high-risk clinical settings.

Other than potency, are all statins the same?

Statins have been shown to interact with metabolic pathways that potentially affect physiologic functions beyond cholesterol balance. We may broadly categorize non-lipid effects of statins as clinically favorable or clinically detrimental. Whether non-lipid effects of statins are of clinical significance and whether there are differences in non-lipid effects among statins remain points of major current controversy. This review evaluates the available information on potential differences among statins in non-lipid effects.

Prevention of Cardiovascular Events in Elderly People

BACKGROUND AND OBJECTIVE

Cardiovascular disease has been identified as the leading cause of morbidity and mortality in developed countries. Given the increase in life expectancy and the development of cardiovascular preventive measures, it has become increasingly important to detect and prevent cardiovascular diseases in the elderly. We reviewed the scientific literature concerning cardiovascular prevention to assess the importance of cardiovascular preventive measures in old (> or =65 years of age) individuals.

METHODS

We undertook a systematic search for references relating to prevention of cardiovascular disease in the elderly, mainly ischaemic stroke, coronary artery disease and heart failure, on the MEDLINE database 1962-2005. For cardiovascular prevention by drugs or surgery, emphasis was placed on randomised controlled trials, review articles and meta-analyses. For cardiovascular prevention by lifestyle modification, major cohort studies were also considered.

RESULTS

Stroke, coronary heart disease and heart failure were found to be the main targets for cardiovascular prevention in published studies. Antihypertensive treatment has proven its efficacy in primary prevention of fatal or nonfatal stroke in hypertensive and high-risk patients >60 years of age, particularly through treatment of systolic hypertension. Systolic blood pressure reduction is equally important in the secondary prevention of stroke. Similarly, in nonvalvular atrial fibrillation, an adjusted dose of warfarin with a target International Normalized Ratio (INR) of between 2 to 3 prevents ischaemic stroke in elderly patients with an acceptable haemorrhagic risk but is still under prescribed. Antiplatelet agents are indicated in elderly patients with nonembolic strokes. Few large-scale studies have investigated the effect of HMG-CoA reductase inhibitors (statins) on stroke prevention in old individuals. To date, the largest trials suggest a beneficial effect for stroke prevention with use of statins in high-risk elderly subjects < or =82 years of age. Carotid endarterectomy is indicated in carotid artery stenosis >70% and outcomes are even better in elderly than in younger patients. However, medical treatment is still the first-line treatment in asymptomatic elderly patients with <70% stenosis. In ischaemic heart disease, different trials in elderly individuals have shown that use of statins, antithrombotic agents, beta-adrenoceptor antagonists and ACE inhibitors plays an important role either in primary or in secondary cardiovascular prevention. Hormone replacement therapy has been used to treat climacteric symptoms and postmenopausal osteoporosis and was thought to confer a cardiovascular protection. However, controlled trials in elderly individuals changed this false belief when it was found that there was no benefit and even a harmful cardiovascular effect during the first year of treatment. Smoking cessation, regular physical activity and healthy diet are, as in younger individuals, appropriate and effective measures for preventing cardiovascular events in the elderly. Finally, antihypertensive treatment and influenza vaccination are useful for heart failure prevention in elderly individuals.

CONCLUSIONS

Cardiovascular prevention should be more widely implemented in the elderly, including individuals aged > or =75 years, and this might contribute to improved healthy status and quality of life in this growing population.

Optimal management of hyperlipidemia in primary prevention of cardiovascular disease

Cardiovascular disease (CVD) in the developed countries continues to grow at an epidemic proportion. There are a significant number of young adults with no clinical evidence of CVD, but who have two or more risk factors that predispose them to CV events and death. Many of these risk factors are modifiable, and by controlling these factors, the CVD burden can be decreased significantly. Recent statistics have shown that, if all major forms of CVD were eliminated, the life expectancy would rise by almost 7 years. Hence it is imperative that primary prevention efforts should be initiated at a young age to avert decades of unattended risk factors. Hyperlipidemia has been linked to CVD almost a century ago. Since then various clinical trials have not only supported this link, but have also shown the CV benefits in aggressively treating patients with hyperlipidemia. In this generation, we have various therapeutic agents that are capable of reducing the elevated lipid levels. With drugs like statins, we are able to reduce the risk of CVD by about 30% and avoid major adverse events. Newer drugs are being researched and introduced in the treatment of hyperlipidemia in humans. These can be used in combination therapy resulting in optimal levels of lipids. The new National Cholesterol Education Program (NCEP)/Adult Treatment Panel III (ATP III) guidelines have come as a wake-up call to clinicians about primary prevention of CVD through strict lipid management and multifaceted risk management approach in the prevention of CVD.

Role of statin therapy in the coronary bypass patient

Statins have been proven to prevent or delay ischemic events in patients at risk for atherosclerotic coronary disease. Increasing evidence suggests that statin therapy is also beneficial to patients undergoing coronary revascularization. In this review statin therapy will be shown to improve vein graft patency, minimize recurrent ischemic events, and decrease the need for repeat revascularization procedures in patients who have undergone coronary artery bypass grafting.

Statin drugs do not affect serum complement activation in vitro

Statin drugs prevent coronary heart disease through anti-inflammatory mechanisms in addition to the well-known reduction of low-density lipoproteins. The complement system plays an essential role in the inflammatory response and has been postulated to be modified by statins. A direct role for statins in complement activation, however, has not been previously investigated. We therefore studied the effect of statins on in vitro complement activation. Pravastatin, atorvastatin and the active metabolite of the latter, ortho-hydroxy atorvastatin, were added to normal human serum and incubated for 1 h in the absence or presence of aggregated immunoglobulin (classical pathway activation) or cobra venom factor (alternative pathway activation). The degree of complement activation, as detected by specific complement-activation products for the classical pathway (C1rs-C1-inhibitor complexes), the combined classical and lectin pathway (C4bc), the alternative pathway (C3bBbP) and the final common pathway (C3bc and TCC), was not affected by pre-incubation of the serum with any of the statins. Statins do not affect complement activation directly, but indirect effects in vivo may well be operative.

Inflammation, immunity, and HMG-CoA reductase inhibitors: statins as antiinflammatory agents?

According to traditional thinking, atherosclerosis results from passive lipid deposition in the vascular wall. Thus, therapies predominantly targeted lipid metabolism. The contemporary view of atherosclerosis, however, has broadened to include an active and complex role for inflammation, orchestrated in part by mediators of the immune system. This recognition prompted the question of whether antiinflammatory interventions might provide a novel avenue for the treatment of atherosclerosis. Uncertainties about the type of antiinflammatory regimen and appropriate patient selection currently hamper clinical investigation. Yet cardiovascular scientists have begun to address these questions at the bench, in experimental models, and indirectly in humans. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A HMG-CoA reductase (statins) have emerged as promising tools with dual functions. Originally designed to target elevated lipids, the "traditional" cause of atherosclerosis, statins might also confer cardiovascular benefit by directly or indirectly modulating the inflammatory component of this prevalent disease. Yet controversy persists regarding the (clinical) relevance of these potential non-LDL-lowering "pleiotropic" functions of statins. This overview addresses the controversy by reviewing in vitro and in vivo evidence regarding statins as antiinflammatory agents.

Role of thrombotic and fibrinolytic factors in acute coronary syndromes

There is a growing body of literature concerning the contribution of hemostatic factors to the development of cardiovascular disease. The mechanisms of the coagulation/fibrinolytic system are complicated and one factor is intimately interrelated with another; thus the contribution of each factor cannot be clearly understood, unless hemostatic factors are considered in accordance with endothelial function and vessel morphology. Although there are many clinical studies about the correlation between hemostatic factors and cardiovascular risk, the results are inconsistent and conflicting at times. Fibrinogen and D-dimer are associated with atherosclerosis or coronary events across multiple studies, even after multivariate adjustment. But the hemostatic factors are intimately correlated, so it can be said that focusing on one to the exclusion of others is inappropriate. The clinical trials with statins or angiotensin converting enzyme inhibitors have shown favorable effects on the prognosis of cardiovascular disease. The study of hemostatic factors in relation to these drugs has provided insights into understanding how these drugs produce beneficial effects.

Superior short-term cholesterol control and achievement of the adult treatment panel III low-density lipoprotein goals with initiation of statin therapy by the time of hospital discharge following acute myocardial infarction

In a community-based population, we compared serum cholesterol concentrations following hospital discharge after acute myocardial infarction based on statin therapy at the time of hospital discharge. At the time of follow-up cholesterol measurement, patients discharged from the hospital on a statin had lower mean low-density lipoprotein (LDL) (106.4 vs 116.7 mg/dl, p <0.01) and total cholesterol (182.2 vs 193.6 mg/dl, p <0.01) concentrations, larger absolute reductions in LDL (-24.7 vs -4.7 mg/dl, p <0.01) and total cholesterol (-24.2 vs -0.1 mg/dl, p <0.01) from pre-myocardial infarction levels, and superior attainment of the Adult Treatment Panel III LDL goal of <100 mg/dl at the time of follow-up compared with patients who were discharged without a statin (49% vs 33%; adjusted odds ratio 2.56; p <0.01).

Effects of HMG-CoA reductase inhibitors on coagulation and fibrinolysis processes

Recent large clinical trials have demonstrated that HMG-CoA reductase inhibitors, or statins, markedly reduce morbidity and mortality when used in the primary and secondary prevention of cardiovascular disease. It has been established that the benefits of statin therapy in cardiovascular disease can be explained not only by the lipid-lowering potential of statins but also by nonlipid-related mechanisms (so-called "pleiotropic effects") that contribute to the positive effect of statins on the incidence of cardiovascular events. The coagulation and fibrinolytic systems are two separate but reciprocally linked enzyme cascades that regulate the formation and breakdown of fibrin. Numerous studies have demonstrated that disturbances of coagulation and fibrinolysis contribute to the development and progression of atherosclerosis, and that they affect the incidence of atherosclerosis-related clinical events. High plasma levels or activities of fibrinogen, factor VII, factor VIII, von Willebrand factor (vWF), soluble thrombomodulin, tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) are thought to be associated with increased morbidity and mortality related to cardiovascular disease. Experimental studies and many clinical studies have recently shown that statins produce favourable effects on haemostatic parameters, including those that are risk factors for cardiovascular disease. Statins diminish procoagulant activity, which is observed at different stages of the coagulation cascade, including tissue factor (TF) activity, conversion of prothrombin to thrombin and thrombin activity. In some studies, statins also reduced fibrinogen levels. By altering the levels and activities of tPA and PAI-1, statins seem to stimulate fibrinolysis. The data on the effects of combined treatment with statins and other drugs on haemostasis are rather limited. They suggest that statins combined with fibric acid derivatives, omega-3 fatty acids and 17beta-estradiol are superior to statins alone. The only two clinical studies performed in patients with acute coronary syndromes showed a relatively weak effect of statins on haemostasis in those patients. Although various statins may produce different effects on individual variables, there are no convincing data showing that differences in their physicochemical and pharmacokinetic properties significantly alter their net effect on excessive procoagulant activity. Apart from the lipid-lowering effect, statins suppress the synthesis of several important nonsterol isoprenoids derived from the mevalonate pathway, especially farnesyl and geranylgeranyl pyrophosphates, which via enhanced protein prenylation, are involved in the regulation of many cellular processes. It is presumed that the inhibitory effect of statins on the mevalonate pathway is involved in the regulation of some key steps of coagulation and fibrinolysis processes. In this way they probably regulate the synthesis of TF, tPA and PAI-1, and perhaps they also control the generation and activity of thrombin. The beneficial effects of statins on coagulation and fibrinolysis may be responsible for their ability to decrease the number of cardiovascular events. The lipid-independent effects of statins on haemostasis may contribute to the marked decrease in the incidence rates of mortality, hospitalisation and revascularisation in patients treated with these drugs.

[Non-lipid effects of statins: myth or fact?]

Hydroxy-methylglutaryl coenzyme A reductase-inhibitors (HMG-CoA [statins]) are currently the most effective method to pharmacologically decrease total plasma cholesterol levels. A number of multicenter studies have demonstrated, that statins administered for several years lead to a significant reduction of cardiovascular events and mortality compared with placebo. Apart from the well known LDL- and cholesterol lowering effect, statins have been postulated to exert beneficial effects on mortality due to so called 'non-lipid effects'. There is circumstantial evidence from a number of experimental studies that statins can improve endothelial function, exert anti-inflammatory and anti-oxidative effects, stabilize arteriosclerotic plaque and inhibit proliferation and activation of smooth muscle cells. However, the clinical implications of these beneficial 'non-lipid effects' are unclear, but appear to exert only a minor role in comparison to the lowering effect of statins on total plasma cholesterol levels.

[Statins and cerebral ischemia]

<zakljucak> CVB su vodeci uzrok invalidnosti u svetu, drugi uzrok mortaliteta u nerazvijenim zemljama (na trecem mestu u razvijenim zemljama), a jedna trecina bolesnika umire unutar prvih 6 meseci od razbolevanja (95, 96). Ovo su zvanicni podaci Svetske zdravstvene organizacije, a statistika je otisla korak dalje i pokazala da u SAD svake 53. sekunde jedan covek oboli od CVB (97). Mozda bi pricu o statinima i IBM trebalo zavrsiti ovim izrazito nepovoljnim epidemioloskim podacima vezanim za CVB, koji naglasavaju znacaj iznalazenja adekvatne terapije koja bi smanjila rizik obolevanja (98), kao i ogromne troskove vezane za lecenje i posledicnu invalidnost. Aspirin dovodi do redukcije vaskularnog mortaliteta i morbiditeta vezanog za CVB od 13% klopidogrel do 22% (99), a statini nezavisno od upotrebe drugih lekova ukljucujuci i aspirin, do 30%. Imajuci u vidu sve ove izrazito dobre rezultate lecenja statinima, uz dozu rezervisanosti vezanu za eventualne udaljene efekte ove terapije, nema sumnje da se radi o lekovima koji ce uticati na promenu celokupnog pristupa lecenju bolesnika sa rizikom od IBM.

Hemostatic effects of atorvastatin versus simvastatin

OBJECTIVE

To compare the effects of simvastatin and atorvastatin on hemostatic parameters.

METHODS

Sixty-one patients with primary hypercholesterolemia without coronary heart disease were treated with atorvastatin 10-20 mg/d or simvastatin 10-20 mg/d. At baseline, 4, 12, and 24 weeks, lipid levels such as low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), very-low-density lipoprotein cholesterol (VLDL-C), triglycerides (TGs), and hemostatic parameters such as platelet counts, partial thromboplastin time (PTT) prothrombin time (PT), and fibrinogen levels were measured.

RESULTS

At 12 weeks, the doses of the statins were increased to 20 mg/d in 10 of 35 (28.5%) patients treated with atorvastatin and 18 of 26 (69.2%) patients treated with simvastatin when the target level of LDL-C (130 mg/dL) was not reached. Mean doses were atorvastatin 12.8 mg/d and simvastatin 16.9 mg/d. After 24 weeks, 5 patients (14.3%) in the atorvastatin group and 4 patients (15.3%) in the simvastatin group had not reached the goal. In patients with diabetes, target level (LDL-C <100 mg/dL) was not reached in 35.7% of patients in the atorvastatin group and 44.4% of patients in the simvastatin group. Both simvastatin and atorvastatin were effective in lowering TC and LDL-C levels (p < 0.001). Atorvastatin lowered TGs significantly (p < 0.01). Neither atorvastatin nor simvastatin significantly reduced VLDL-C levels. HDL-C levels increased with atorvastatin, but there was no significant difference between the 2 groups. Platelet counts decreased with both statins nonsignificantly. Moreover, fibrinogen levels decreased with simvastatin and atorvastatin, but these reductions were significant only for simvastatin (p < 0.05). We detected prolongation of the PT with both drugs (p < 0.05); however, prolongation of the PTT was significant only with simvastatin (p < 0.001). Effectiveness of both statins on lipid and hemostatic parameters was dose related. Adverse effects were seen in 5 patients (14.2%) treated with atorvastatin and 3 patients (11.5%) treated with simvastatin. Elevations in serum transaminase levels >3 times the upper limit of normal and in creatine phosphokinase >5 times the upper limit of normal were not observed in any group.

CONCLUSIONS

Atorvastatin was more effective than simvastatin on lipid parameters, although statistically insignificantly, while simvastatin produced more significant changes than atorvastatin on hemostatic parameters. The mean dose of simvastatin was greater than that of atorvastatin. Both statins had increased effects on lipid and hemostatic parameters when doses were increased. Atorvastatin and simvastatin were well tolerated. Different effects of statins on lipid levels and on coagulation parameters should be considered in patients with hypercholesterolemia and tendency to coagulation, especially in preventing thrombotic events. Further studies in larger trials are needed to confirm these observations.

Prevention of stroke and dementia with statins: Effects beyond lipid lowering

Stroke is a major cause of mortality and morbidity. The epidemiologic association between elevated serum cholesterol and stroke risk is controversial. However, recent secondary prevention studies with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have demonstrated a significant reduction in ischemic stroke without an increase in hemorrhagic stroke. Statins probably reduce stroke by a variety of mechanisms, including modulation of precerebral atherothrombosis in the aorta and the carotid artery, thus preventing plaque disruption and artery-to-artery thromboembolism. Statins also improve endothelial homeostasis by increasing the bioavailability of nitric oxide, which orchestrates the paracrine antiatherosclerotic functions of the endothelium. Studies in experimental models of ischemic stroke show that statin therapy reduces brain infarct size and improves neurologic outcome by directly upregulating brain endothelial nitric oxide synthase. Putative anti-inflammatory actions of statins may also contribute to neuroprotection and stroke prevention. Although the clinical benefit of statins largely depends on lowering low-density lipoprotein cholesterol, accumulating data indicate that many of the pleiotropic effects of statins are attributable to the cellular consequences of depletion of intermediates in the cholesterol biosynthetic pathway (isoprenoids). These molecules play fundamental roles in cell growth, signal transduction, and mitogenesis. In addition to reducing stroke risk, emerging data suggest that statins may reduce dementia. Further studies are needed to fully address the role of statins in the prevention of stroke in patients without established vascular disease and the role of cholesterol modulation in the treatment of dementia.

Effects of statins on the vasculature: Implications for aggressive lipid management in the cardiovascular metabolic syndrome

The cardiovascular metabolic syndrome is a family of risk factors that predispose patients to develop diabetes and cardiovascular disease. Indeed, macrovascular, not microvascular, disease is the leading cause of death in these patients. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) exert both direct and indirect (cholesterol-lowering) effects on the vasculature. Clinical trials have shown that these agents reduce cardiovascular disease and cerebrovascular disease in persons with diabetes. However, their beneficial effects on diabetic dyslipidemia do not account for all of the observed risk reduction. Positive effects on nitric oxide metabolism, inflammation, coagulability, and adhesion of cells to the vascular endothelium likely contribute to the mechanism of action of these agents. These pleiotropic effects of statins on the vasculature will be discussed in this review.

Beyond lipid lowering: the role of statins in vascular protection

The introduction of the hydroxy methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) in 1987 was a major advance in the prevention and treatment of cardiovascular disease. Several landmark clinical trials have demonstrated the benefit of lipid lowering with statins for the primary and secondary prevention of coronary heart disease (CHD), namely The Scandinavian Simvastatin Survival Study (4S), Cholesterol And Recurrent Events (CARE), Long-term Intervention with Pravastatin in Ischemic Disease (LIPID), West of Scotland Coronary Prevention Study (WOSCOPS) and Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS). Although it is widely accepted that the majority of clinical benefit obtained with statins is a direct result of their lipid-lowering properties, these agents appear to display additional cholesterol-independent or pleiotropic effects on various aspects of cardiovascular disease, including improving endothelial function, decreasing vascular inflammation and enhancing plaque stability. Although the full impact of statin therapy on each of these processes is not fully understood, ongoing studies with current and new statins are likely to shed further light on the potential cholesterol-independent benefits of these agents.

Lack of therapeutic interchangeability of HMG-CoA reductase inhibitors

OBJECTIVE

To review relevant literature and provide an opinion on the class effect of hydroxymethylglutaryl coenzyme A reductase inhibitors (statins).

DATA SOURCES

Primary and review articles were identified by MEDLINE search (1990-July 2002).

STUDY SELECTION AND DATA EXTRACTION

Editorials, studies, and review articles related to the class effect or therapeutic interchangeability of statins were reviewed. Also included was information that is relevant to this topic.

DATA SYNTHESIS

Although statins share common main actions, they may have clinically important differences in terms of efficacy and safety. At fixed or allowable dosages, rosuvastatin, atorvastatin, and simvastatin produced greater low-density lipoprotein cholesterol-lowering effects compared with other statins. Some statins have shown reduction in either cardiovascular and/or total mortality. Statins also differ in their structure, pharmacokinetics, potency, and rate of metabolism, any or all of which may have clinical significance. Although inconclusive, subtle differences in nonlipid effects of some statins may have contributed to positive benefits observed in clinical studies. As a result of drug-related deaths, cerivastatin was withdrawn voluntarily from the market, which may raise the question whether there is therapeutic interchangeability (due to class effect) among statins.

CONCLUSIONS

Despite the competition for market share and strategies attempting to identify differences in therapeutic value, few head-to-head comparisons between statins have been performed. The limited, available data suggest that statins are not therapeutically interchangeable.

Statin lipid-lowering therapy for acute myocardial infarction and unstable angina: efficacy and mechanism of benefit

The use of statin agents in patients with acute coronary syndromes (ACSs) remains an area of intense clinical interest. Statin therapy has an established secondary preventive benefit in patients with coronary artery disease, and its extension to ACS seems logical. A number of observational studies have shown an association between initiation of statin therapy early in ACS and improved clinical outcome. Additionally, 4 randomized controlled trials have examined the use of statin therapy for ACS: the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study, the Pravastatin Turkish Trial, the Fluvastatin on Risk Diminishing After Acute Myocardial Infarction (FLORIDA) study, and the Lipid-Coronary Artery Disease (L-CAD) study. Three of these trials showed a benefit with early initiation of statin therapy, whereas 1 trial demonstrated neither benefit nor harm. All the available trials lacked the power and design to sufficiently evaluate whether early initiation of statin therapy reduces mortality and reinfarction in patients with ACS. Four ongoing trials have been designed and sufficiently powered to determine whether statin therapy reduces the risk of death and reinfarction when initiated early in ACS treatment. A body of evidence suggests that the pleiotropic actions of statin agents might modulate benefit in ACS. This article summarizes the available data and provides a rationale for early initiation of statin therapy for patients with ACS.

Effect of early statin therapy after acute coronary syndromes: a concise review of the recent data

HMG Co-A reductase inhibitors(statins) have been shown, in three large randomized trials, to decrease adverse cardiac events in patients with clinically evident coronary artery disease. All of these trials have excluded patients with an acute coronary syndrome within the three months prior to enrollment. Statin therapy is thought to stabilize coronary plaque and decrease the risk of plaque rupture. Statins have been shown to quickly reduce levels of LDL-C in addition to altering systemic inflammatory responses, improving endothelial function, and reducing platelet aggregation and activation. These mechanisms are potentially beneficial in the setting of acute coronary syndromes, a time of profound plaque instability. There is a growing body of evidence supporting the early initiation of statin therapy in the setting of acute coronary syndromes. This paper reviews the available data from randomized-controlled trials and observational studies evaluating the effect of early statin initiation during, or soon following, an acute coronary syndrome.

Pharmacokinetic-pharmacodynamic drug interactions with HMG-CoA reductase inhibitors

The HMG-CoA reductase inhibitors (statins) are effective in both the primary and secondary prevention of ischaemic heart disease. As a group, these drugs are well tolerated apart from two uncommon but potentially serious adverse effects: elevation of liver enzymes and skeletal muscle abnormalities, which range from benign myalgias to life-threatening rhabdomyolysis. Adverse effects with statins are frequently associated with drug interactions because of their long-term use in older patients who are likely to be exposed to polypharmacy. The recent withdrawal of cerivastatin as a result of deaths from rhabdomyolysis illustrates the clinical importance of such interactions. Drug interactions involving the statins may have either a pharmacodynamic or pharmacokinetic basis, or both. As these drugs are highly extracted by the liver, displacement interactions are of limited importance. The cytochrome P450 (CYP) enzyme system plays an important part in the metabolism of the statins, leading to clinically relevant interactions with other agents, particularly cyclosporin, erythromycin, itraconazole, ketoconazole and HIV protease inhibitors, that are also metabolised by this enzyme system. An additional complicating feature is that individual statins are metabolised to differing degrees, in some cases producing active metabolites. The CYP3A family metabolises lovastatin, simvastatin, atorvastatin and cerivastatin, whereas CYP2C9 metabolises fluvastatin. Cerivastatin is also metabolised by CYP2C8. Pravastatin is not significantly metabolised by the CYP system. In addition, the statins are substrates for P-glycoprotein, a drug transporter present in the small intestine that may influence their oral bioavailability. In clinical practice, the risk of a serious interaction causing myopathy is enhanced when statin metabolism is markedly inhibited. Thus, rhabdomyolysis has occurred following the coadministration of cyclosporin, a potent CYP3A4 and P-glycoprotein inhibitor, and lovastatin. Itraconazole has been shown to increase exposure to simvastatin and its active metabolite by at least 10-fold. Pharmacodynamically, there is an increased risk of myopathy when statins are coprescribed with fibrates or nicotinic acid. This occurs relatively infrequently, but is particularly associated with the combination of cerivastatin and gemfibrozil. Statins may also alter the concentrations of other drugs, such as warfarin or digoxin, leading to alterations in effect or a requirement for clinical monitoring. Knowledge of the pharmacokinetic properties of the statins should allow the avoidance of the majority of drug interactions. If concurrent therapy with known inhibitors of statin metabolism is necessary, the patient should be monitored for signs and symptoms of myopathy or rhabdomyolysis and the statin should be discontinued if necessary.

Clinical review 145: Pleiotropic effects of statins: lipid reduction and beyond

There is accumulating evidence that statins have beneficial effects that are independent of their classical actions on lipoproteins. These effects include reductions in inflammation in the vasculature, kidney, and bone. Potential beneficial effects of these agents include enhancement of nitric oxide production in vasculature and the kidney. These agents appear to reduce bone fractures and may improve insulin sensitivity and reduce the likelihood of persons progressing from impaired glucose tolerance to type II diabetes. Potential beneficial pleiotropic effects of statins are covered in this review.

A pharmacoepidemiological assessment of the effect of statins and fibrates on fibrinogen concentration

Plasma fibrinogen is strongly associated with cardiovascular morbi-mortality. We investigated in the large cohort of the D.E.S.I.R. (data from an epidemiological study on the insulin resistance syndrome) study, the relationship between change in fibrinogen concentration over a 3-year follow-up and fibrate and statin use. Fibrinogen concentrations were higher at baseline among individuals treated with statins (n=130) compared to those treated with fibrates (n=251), even after adjustment for confounding factors (including total cholesterol, HDL cholesterol and triglycerides) (mean (S.D.): 2.8 (0.6) vs. 3.1 (0.6), P<0.001). We compared change in fibrinogen concentrations at 3 years of follow-up, between individuals who started fibrate (n=126) or statin (n=127) treatment during the follow-up and individuals (n=3906) who stayed without treatment during this period. After adjustment for baseline fibrinogen level, age, sex and changes in total cholesterol, triglycerides and alcohol intake, fibrinogen concentration decreased after fibrate treatment, while it increased after statin treatment and in those not using lipid lowering drugs (-0.07 (0.54) vs. 0.10 (0.54) vs. 0.08 (0.52) g/l respectively, P=0.01). No differences were observed between different statins or different fibrates. In conclusion, fibrates in contrast with statins may combine lipid-lowering with a beneficial effect on fibrinogen. This effect is independent of changes in cholesterol and triglyceride concentrations.

Atorvastatin improves blood rheology in patients with familial hypercholesterolemia (FH) on long-term LDL apheresis treatment

To determine the effect of atorvastatin on blood rheology in patients with familial hypercholesterolemia (FH) on regular LDL apheresis, we prospectively studied the rheological variables fibrinogen, plasma viscosity, red cell aggregation, whole blood viscosity, hematocrit and platelet aggregation in 12 patients (two homozygous, ten heterozygous) before and during treatment with atorvastatin. Baseline values of red cell aggregation and whole blood viscosity were increased in FH patients on regular LDL apheresis compared with healthy controls (P<0.05), whereas fibrinogen, plasma viscosity and hematocrit were similar in the two groups. Treatment with atorvastatin reduced red cell aggregation (P<0.01), whole blood viscosity (P<0.01), plasma viscosity (P<0.01) and platelet aggregation (P<0.05), but caused a slight increase in plasma fibrinogen (by 5%; P<0.01). Our findings suggest that atorvastatin improves blood rheology in patients with FH on regular LDL-apheresis. This improvement in blood flow properties may contribute to the well-known beneficial effects of atorvastatin on cardiovascular risk in patients with severe hyperlipidemia and atherosclerotic vascular disease.

Effectiveness of statins in acute coronary syndromes

Over the past several years, results of clinical trials of lipid lowering have increased our understanding of the pathophysiology of coronary atherosclerosis and ischemia. Evidence is accumulating that cholesterol lowering has potential anti-ischemic effects and may have immediate consequences that have a favorable impact on coronary events, possibly even acute coronary syndromes. Yet, less than one half of all patients hospitalized for acute coronary syndromes have their cardiovascular risks appropriately modified. The results of recent statin trials provide impetus for the implementation of aggressive risk-reduction strategies in patients with coronary atherosclerosis, including those with recent acute coronary syndromes. Prevention is now a viable therapeutic goal.

Statin therapy and stroke prevention

Hypercholesterolemia has not traditionally been considered an important risk factor in the pathogenesis of stroke. However, recent studies show that statin therapy significantly reduces ischemic stroke for patients with established coronary artery disease. Statin therapy may reduce stroke through amelioration of precerebral atherosclerosis in the carotid artery and the aorta. Anti-atherosclerotic, anti-inflammatory, and antithrombotic actions of statins occur within the blood and in plaque. Statins may also protect against cerebral ischemia through beneficial modulation of the brain endothelial nitric oxide system. Ongoing studies are exploring the role of statin therapy in the primary prevention of stroke and in the prevention of cognitive decline and multi-infarct cerebrovascular disease.

Plasma fibrinogen level and long-term prognosis in Norwegian middle-aged patients with previous myocardial infarction. A 10 year follow-up study

OBJECTIVES

To investigate the prognostic value of plasma fibrinogen level amongst middle-aged survivors of myocardial infarction (MI).

DESIGN

Prospective cohort study.

SETTINGS

Determination of fibrinogen and other prognostic variables in MI patients recruited in a presumably stable phase of coronary heart disease (CHD).

SUBJECTS

A total of 247 middle-aged CHD patients (54 women and 193 men) who had their first MI at age < or = 60 (women) or < or = 55 (men) were recruited at least 3 months after (mean 2.1 years) the most recent MI.

MAIN OUTCOME MEASURES

The primary endpoint was total mortality, and the secondary endpoint was cardiac deaths. The tertiary endpoint was major cardiac events (cardiac death, MI and cardiac arrest).

RESULTS

During a follow-up period of 10 years a total of 44 patients had died, 36 from cardiac causes. Major cardiac event occurred in 70 patients. After adjusting for age, ejection fraction (EF), total serum cholesterol (TC), smoking and hypertension, patients in the top quartile of fibrinogen (> or = 4.0 g L-1) had a relative risk (RR) of 1.8 (95% CI 1.0-3.6) (P = 0.07) for death of all causes. The top quartile of fibrinogen was a stronger predictor of cardiac death; RR = 2.2 (95% CI 1.1-4.4) (P = 0.03), whilst the effect on the endpoint major cardiac event was not significant; RR=1.1 (95% CI 0.6-1.9) (P = 0.69).

CONCLUSIONS

A plasma fibrinogen level in the top quartile predicted cardiac death in middle-aged patients who had suffered MI.