Reaching goal in hypercholesterolaemia: dual inhibition of cholesterol synthesis and absorption with simvastatin plus ezetimibe

Effects and Safety of Statin and Ezetimibe Combination Therapy in Patients with Chronic Kidney Disease: A Systematic Review and Meta-Analysis

The efficacy and safety of statin and ezetimibe combination therapy in patients with chronic kidney disease (CKD) remains unclear. To assess the effect of statin and ezetimibe combination therapy on controlling lipid profiles and reducing cardiovascular events in patients with CKD, we conducted a systematic review and meta-analysis. We selected randomized controlled trials comparing this combination therapy with statin monotherapy or placebo in patients with CKD from the PubMed, Embase, and Cochrane Central Register of Controlled Trials databases published before September 1, 2018 on the Internet. Eight articles on seven studies, with a total of 14,016 patients with CKD, were selected from 412 full-text articles. Statin and ezetimibe combination therapy had beneficial effects on serum total cholesterol (weighted mean difference (WMD) -20.31 mg/dL, 95% confidence interval (CI), -26.87 to -13.75 mg/dL, P < 0.001), low-density lipoprotein cholesterol (WMD -17.22 mg/dL, 95% CI, -18.93 to -15.51 mg/dL, P < 0.001), and triglycerides (WMD -15.08 mg/dL, 95% CI, -23.41 to -6.75 mg/dL, P < 0.001) compared with statin monotherapy. Statin and ezetimibe combination therapy significantly reduced all-cause mortality and major adverse cardiovascular events (risk ratio 0.86, 95% CI, 0.77 to 0.97, P = 0.01). The incidence of adverse events was low, with no significant difference between statin and ezetimibe combination therapy and statin monotherapy. In conclusion, the statin and ezetimibe combination therapy significantly improved serum lipid profiles and reduced risks of all-cause deaths and major adverse cardiovascular events compared with the control group in patients with CKD.

ANMCO Scientific Statement: clinical management of hypercholesterolaemia in patients with acute coronary syndromes

LDL cholesterol (LDL-C) reduction after Acute Coronary Syndromes (ACS) is associated with a significant decrease in subsequent atherosclerotic cardiovascular events. Accordingly, international guidelines recommend a reduction of LDL-C below 70 mg/dL in ACS patients. Such a result can be effectively accomplished in most cases by using high intensity statins. In selected cases, the association with ezetimibe may be necessary in order to achieve recommended LDL-C targets. This document outlines management strategies that can be consistently implemented in clinical practice in order to achieve and maintain guidelines recommended therapeutic goals.

ANMCO/ISS/AMD/ANCE/ARCA/FADOI/GICR-IACPR/SICI-GISE/SIBioC/SIC/SICOA/SID/SIF/SIMEU/SIMG/SIMI/SISA Joint Consensus Document on cholesterol and cardiovascular risk: diagnostic-therapeutic pathway in Italy

Atherosclerotic cardiovascular disease still represents the leading cause of death in Western countries. A wealth of scientific evidence demonstrates that increased blood cholesterol levels have a major impact on the outbreak and progression of atherosclerotic plaques. Moreover, several cholesterol-lowering pharmacological agents, including statins and ezetimibe, have proved effective in improving clinical outcomes. This document focuses on the clinical management of hypercholesterolaemia and has been conceived by 16 Italian medical associations with the support of the Italian National Institute of Health. The authors discuss in detail the role of hypercholesterolaemia in the genesis of atherosclerotic cardiovascular disease. In addition, the implications for high cholesterol levels in the definition of the individual cardiovascular risk profile have been carefully analysed, while all available therapeutic options for blood cholesterol reduction and cardiovascular risk mitigation have been explored. Finally, this document outlines the diagnostic and therapeutic pathways for the clinical management of patients with hypercholesterolaemia.

The Role of Endocannabinoid System Blockade in the Treatment of the Metabolic Syndrome

This review considers the use of the first selective blocker of the cannabinoid receptor type 1, rimonabant, to reduce weight and improve cardiovascular disease risk factors in obese patients with metabolic syndrome or multiple cardiovascular disease risk factors. In 4 large trials-Rimonabant in Obesity (RIO)-Lipids, RIO-Europe, RIO-North America, and RIO-Diabetes-after 1 to 2 years of treatment, rimonabant (20 mg/day) led to a significantly greater weight loss and reduction in waist circumference compared with placebo. Treatment with rimonabant was also associated with other favorable changes, including better glycemic control in type 2 diabetes mellitus, improved lipid profile, reduced blood pressure, increased adiponectin levels, fall in high-sensitivity C-reactive protein concentrations, and an overall decrease in the prevalence of the metabolic syndrome. Initial experience with rimonabant shows that it is generally well tolerated with the most common side effect of mild nausea. Rimonabant may be a useful adjunct to lifestyle and behavior modification in the treatment of obese subjects with metabolic syndrome or multiple cardiometabolic risk factors.

Comparative efficacy of the addition of ezetimibe to statin vs statin titration in patients with hypercholesterolaemia: systematic review and meta-analysis

OBJECTIVE

To systematically review and analyse evidence for cholesterol-lowering efficacy of at least 4 weeks of add-on ezetimibe vs doubling statin dose, in adults with primary hypercholesterolaemia.

RESEARCH DESIGN AND METHODS

MEDLINE, EMBASE and Cochrane databases were searched to identify randomised controlled trials of ezetimibe-statin combination vs statin titration (January 1993 - March 2010). Studies were selected using predefined criteria. Two reviewers conducted screening of articles, critical appraisal and data extraction; a third reviewer resolved disagreements. The difference between treatments was analysed for four co-primary outcomes: mean percentage change from baseline in low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and total cholesterol (TC); and proportion of patients achieving LDL-C treatment goal. Data were combined by two sets of direct comparison fixed and random effects meta-analysis: (1) compared data in the same treatment period between groups; (2) compared the incremental change in lipid levels of add-on ezetimibe vs doubling statin dose. Heterogeneity was assessed using the I(2) statistic.

RESULTS

Thirteen studies including 5080 patients were included in the meta-analyses. Data on simvastatin, atorvastatin and rosuvastatin were analysed. Results for primary and secondary outcomes were in favour of the ezetimibe-statin combination. A significantly greater percentage reduction in LDL-C levels was achieved in patients treated with ezetimibe-statin vs statin monotherapy (weighted mean difference [WMD]: -14.1% [-16.1, -12.1], p < 0.001). Reduction in LDL-C levels attributed to add-on ezetimibe was significantly greater than that for statin dose doubling (WMD: -15.3% [-19.1, -11.4], p < 0.001). Achievement of LDL-C goal favoured add-on ezetimibe over statin titration and was statistically significant (odds ratio: LDL-C treatment goal 2.45 [1.95, 3.08], p = 0.007).

CONCLUSIONS

Meta-analyses were restricted by the limited number of studies with similar trial design and method of statin titration. Results indicate that add-on ezetimibe is significantly more effective in reducing LDL-C levels than doubling statin dose, enabling more patients to achieve LDL-C goal.

Emerging options in the treatment of dyslipidemias: a bright future?

INTRODUCTION

Hypercholesterolemia is a major risk factor for cardiovascular disease (CVD). Low-density lipoprotein cholesterol (LDL-C) reduction has been demonstrated to decrease CVD-related morbidity and mortality. However, several patients do not reach LDL-C target levels with the currently available lipid lowering agents, particularly statins. Lipid and non-lipid parameters other than LDL-C may account for the residual CVD risk after adequate LDL-C lowering with statins.

AREAS COVERED

This review focuses on the efficacy and safety of emerging drugs aiming at high-density lipoprotein cholesterol (HDL-C) elevation (i.e., recombinant or plasma-derived wild-type apolipoprotein (apo) A-I, apo A-I mimetic peptides, reconstituted mutant HDL, partially delipidated HDL and cholesterol ester transfer protein inhibitors), microsomal triglyceride transfer protein inhibitors and antisense oligonucleotides.

EXPERT OPINION

Several lipid modifying agents in development may potently reduce the residual CVD risk. Ongoing and future studies with clinical outcomes will clarify their efficacy in clinical practice.

Cost-effectiveness of rosuvastatin versus ezetimibe/simvastatin in managing dyslipidemic patients in Mexico

OBJECTIVE

The purpose of this analysis was to study the effectiveness and cost-effectiveness of oral rosuvastatin (RSV) 10 mg/day vs. oral ezetimibe/simvastatin (E/S) 10/20 mg/day in patients who met the LDL-C goals set out in the National Cholesterol Education Program (NCEP), Adult Treatment Panel III (ATP III) 2001 and 2004 guidelines, and the percent change in the atherogenic lipid profile in daily outpatient practice in a high specialty Hospital in Mexico City.

METHODS

From January 2004 to December 2005, outpatient medical records in the Cardiology Service were reviewed according to the following criteria: established dyslipidemia diagnosis, triglycerides and serum lipid measurements (TC, LDL-C, HDL-C) taken before receiving drug therapy with either oral RSV 10 mg/day or oral E/S 10/20 mg/day once daily, no other related lipid-lowering treatment administered, and lipid levels recorded at 8 weeks of treatment. A cost analysis was performed from an institutional perspective, using the exchange rate as of October 2006 of 10.9007 pesos / US dollar. A deterministic analysis was performed comparing treatment costs, proportion of patients achieving the ATP III goal, and the percentage decrease in LDL-C. In addition, a stochastic analysis was performed, considering the uncertainty around the estimations for mean cost and mean effectiveness estimations.

RESULTS

Using the ATP III 2001 criteria, the percentage of patients who reached the LDL-C goals was 81.4% for patients who received RSV, while the proportion for patients who received E/S was 58.4% (p < 0.001). Results according to the ATP III 2004 criteria were: RSV, 46.4% vs. E/S, 31.4% (p = 0.04). The cost of a 1% reduction in LDL-C was $2.02 with RSV and $4.09 with E/S. The cost-effectiveness acceptability curve showed that RSV might be more cost-effective than E/S, based on patients who achieved the 2004 goals.

CONCLUSIONS

According to this exploratory, non-controlled retrospective analysis, it can be said that in daily clinical practice in high-cardiovascular-risk Mexican patients, treatment with oral RSV 10 mg/day is more effective and less costly than treatment with the fixed-combination oral E/S 10/20 mg/day.

Clinical experience with ezetimibe/simvastatin in a Mediterranean population

OBJECTIVES

This study aimed to describe the clinical experience of the ezetimibe (EZE)/simvastatin (SIMVA) combination in a hypercholesterolaemic Greek population who did not attain the cholesterol goals on statin treatment alone.

METHODS

Patients already treated with a statin, at any dose, for at least 8 weeks, with LDL-C levels above the goal, (>100, >130 or >160 mg/dl according to their risk category), where the physician chose EZE/SIMVA as appropriate treatment, entered the study. Medical history, demographics and laboratory values were recorded at baseline and 2 months later.

RESULTS

The study included 1514 patients (male 53.4%) of mean age 60.1 + or - 10.5 years. Diabetes mellitus was reported in 29.9% of the patients, 61.2% had hypertension, 39% were obese, 10.5% had a history of myocardial infarction and 6.8% had a history of stroke or peripheral arterial disease. Current and ex-smoking was reported in 46.8%. Atorvastatin (33%) and SIMVA (27.2%) were the most frequently used statins prior to using the EZE/SIMVA regimen. After 2 months of EZE/SIMVA therapy mean LDL-C was reduced by 33%, mean total cholesterol by 26%, mean triglycerides by 15%, while HDL-C was increased by 10%. The percentage of patients who achieved the LDL-C goal with EZE/SIMVA was 73.8%. One serious adverse event, not related to study treatment and 23 adverse events in total were recorded. There was a significant decrease in serum creatinine levels in patients with baseline values greater than 1.0 mg/dl (88 micromol/L).

CONCLUSIONS

Treatment with the EZE/SIMVA combination appears an effective and safe therapeutic option for patients who do not achieve the LDL-C goals on statin therapy alone.

Coronary heart disease and dyslipidemia: a cross-sectional evaluation of prevalence, current treatment, and clinical control in a large cohort of Spanish high-risk patients: the PRINCEPS study

The authors assessed a large cohort of patients with coronary heart disease (CHD) or at high risk for developing CHD in terms of lipid profile, lipid-lowering treatment, and attainment of National Cholesterol Education Program (NCEP) target low-density lipoprotein cholesterol (LDL-C) levels. The investigation was a cross-sectional study involving Spanish outpatients treated in primary or secondary care facilities. From a total of 26,598 attending patients, 12,128 with CHD or CHD risk equivalents were recruited by 1875 physicians; 49% had CHD and 69% had multiple risk factors. Only 25% of patients attained LDL-C values <100 mg/dL, 76.6% patients received lipid-lowering therapy (statins in 95.4% of cases), and 54% of physicians considered that a treatment change was required (the most frequent choice was the addition of ezetimibe to current statin therapy). In this large cohort of high-risk coronary patients, only 25% attained a target LDL-C of <100 mg/dL. These results highlight a need for improved patient care and physician awareness/training.

Efficacy and safety of ezetimibe added on to atorvastatin (20 mg) versus uptitration of atorvastatin (to 40 mg) in hypercholesterolemic patients at moderately high risk for coronary heart disease

The aim of this study was to evaluate the efficacy and safety of ezetimibe 10 mg added to atorvastatin 20 mg compared with doubling atorvastatin to 40 mg in patients with hypercholesterolemia at moderately high risk for coronary heart disease who did not reach low-density lipoprotein (LDL) cholesterol levels <100 mg/dl with atorvastatin 20 mg. In this 6-week, multicenter, double-blind, randomized, parallel-group study, 196 patients treated with atorvastatin 20 mg received atorvastatin 20 mg plus ezetimibe 10 mg or atorvastatin 40 mg for 6 weeks. Adding ezetimibe 10 mg to atorvastatin 20 mg produced significantly greater reductions in LDL cholesterol than increasing atorvastatin to 40 mg (-31% vs -11%, p <0.001). Significantly greater reductions were also seen in non-high-density lipoprotein cholesterol, total cholesterol, and apolipoprotein B (p <0.001). Significantly more patients reached LDL cholesterol levels <100 mg/dl with atorvastatin 20 mg plus ezetimibe compared with atorvastatin 40 mg (84% vs 49%, p <0.001). The 2 treatment groups had comparable results for high-density lipoprotein cholesterol, triglycerides, apolipoprotein A-I, and high-sensitivity C-reactive protein. The incidences of clinical and laboratory adverse experiences were generally similar between groups. In conclusion, the addition of ezetimibe 10 mg to atorvastatin 20 mg was generally well tolerated and resulted in significantly greater lipid-lowering efficacy compared with doubling atorvastatin to 40 mg in patients with hypercholesterolemia at moderately high risk for coronary heart disease.

Metabolomic strategies to identify tissue-specific effects of cardiovascular drugs

BACKGROUND

The number of patients eligible for cardiovascular therapies in general is forecast to increase substantially in the coming decades. However, the current list of potential future cardiovascular blockbuster drugs is alarmingly short. There is thus a clear need for innovative strategies to increase the efficiency of drug development pipelines by establishing new sensitive biomarkers to monitor drug efficacy and safety in the context of complexity of lipoprotein metabolism targeted by the cardiovascular drugs.

METHODS

Metabolomics is a discipline dedicated to the systematic study of small molecules in cells, tissues and biofluids. Since lipids (including cholesterol), as well as other metabolites, are key constituents of lipoprotein particles and are thus part of the complex lipoprotein metabolism that includes exchange of lipids and metabolites with peripheral tissues, cardiovascular drug safety and efficacy needs to be addressed in the context of systemic lipid metabolism.

RESULTS/CONCLUSION

Metabolomics, lipidomics in particular, is expected to make an important impact on the discovery and development of cardiovascular therapies.

Sustained effects in hypercholesterolaemic patients on combined simvastatin/ezetimibe treatment: observational cohort study in clinical practice

BACKGROUND

In order to reduce individual cardiovascular risk, many patients require life-long lipid-lowering therapy, often as a drug combination approach. We aimed to describe the usage pattern, effectiveness and tolerability of long-term treatment with lipid-lowering agents, with particular focus on an oral combination of simvastatin (SIM 10, 20, 40 or 80 mg) plus ezetimibe (EZ 10 mg).

METHODS

A prospective, observational study in 512 general practices throughout Germany. From a sample of patients at moderate or high cardiovascular risk who had previously taken part in a half-year study of an SIM/EZ combination, 5485 patients were documented after 1 year of treatment (mean 58 +/- 16 weeks) with regard to lipid parameters, adverse drug reactions (ADRs) and adverse events.

RESULTS

At the start of follow-up, 78.6% of patients were still on the SIM/EZ combination. At the end of follow-up, mean low density lipoprotein cholesterol (LDL-C) in patients on the combination versus those on other lipid-lowering therapy was reduced by 29.3 vs. 17.6% compared with baseline, total cholesterol by 23.1 vs. 14.5%, mean high density lipoprotein cholesterol (HDL-C) was increased by 15.9 vs. 13.4%, and mean triglycerides were reduced by 16.1 vs. 7.9%. Individual LDL-C targets were achieved by 56.6% on the SIM/EZ combination versus 35.9% on other therapy. In the long term (but not the short term), low acceptance of nutrition counselling as rated by the physician was associated with poor lipid levels. ADRs during follow-up occurred in 18 patients (0.3%; all cases non-serious), with seven cases of myalgia, and three cases each of nausea or arthralgia.

CONCLUSIONS

This observational study showed that long-term therapy with the SIM/EZ combination resulted in sustained beneficial effects on serum lipids and was well-tolerated. Compared to patients with therapy discontinuations or switches, those remaining on the combination had better outcomes regarding lipid status.

The effect of orlistat and ezetimibe, alone or in combination, on serum LDL and small dense LDL cholesterol levels in overweight and obese patients with hypercholesterolaemia

BACKGROUND

Increased concentrations of low density lipoprotein cholesterol (LDL-C), as well as of small dense LDL-C (sdLDL-C), are considered as cardiovascular risk factors.

OBJECTIVE

An assessment of the effects of ezetimibe and orlistat administration, alone or in combination, on LDL-C and sdLDL-C levels (primary endpoint), as well as on anthropometric variables and metabolic parameters (secondary endpoints) in overweight and obese patients [body mass index (BMI)>28 kg/m(2)] with hypercholesterolaemia [total cholesterol>200 mg/dL (5.2 mmol/L)].

METHODS

Eighty six subjects were prescribed a low-fat low-calorie diet and were randomly allocated to receive orlistat 120 mg, 3 times daily (O group), ezetimibe 10 mg/day (E group) or both (OE group) for 6 months.

RESULTS

Significant reductions in LDL-C (-19%, -21%, -32% in groups O, E and OE, respectively, all p<0.01 vs. baseline) and sdLDL-C levels (-45%, -48%, -76% in groups O, E, OE, respectively, all p<0.01 vs. baseline) were observed. Group OE experienced a significantly greater reduction in LDL-C and sdLDL-C levels compared with groups O and E (p<0.05). Furthermore, significant reductions of BMI, homeostasis model assessment (HOMA) index, serum uric acid, transaminase activities and plasma lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) activity were observed in the O and OE groups. Gamma-glutamyl transpeptidase activity and Lp-PLA(2) activity improved significantly more with the combination treatment compared with either orlistat or ezetimibe monotherapy.

CONCLUSIONS

Orlistat and ezetimibe combination had a more favourable effect on LDL-C and sdLDL-C levels in overweight and obese hypercholesterolaemic patients than either drug alone. Furthermore, orlistat, alone or in combination with ezetimibe, additionally improved several anthropometric and metabolic variables.

Achieving Vascular Risk Factor Targets: A Survey of a London General Practice

We assessed lipid goal achievement in patients at high risk for vascular events from a general practice (London, United Kingdom). Patients were identified as those with a prescription for hypolipidaemic medication, a significant (>20%) Framingham risk, and from the myocardial infarction register. Two hundred forty-five patients were currently taking a statin (average dose, 23.1 mg/day). Cholesterol, high-density lipoprotein—cholesterol, low-density lipoprotein—cholesterol, and triglycerides changed significantly following statin treatment. Of 285 patients who had taken statins at some time point, 11 (3.9%) were intolerant, 5 of which subsequently tolerated another statin. Approximately 10.1% of patients discontinued statin treatment for unclear reasons. Only 64 patients (29.1% of 220) reached the Joint British Societies' Guidelines on Prevention of Cardiovascular Disease target of a total cholesterol of <4.0 mmol/L; 50 patients (38.8% of 129) reached the low-density lipoprotein—cholesterol target of <2.0 mmol/L. This value of low-density lipoprotein—cholesterol is similar to that recommended by the American Heart Association/American College of Cardiology. With regard to the General Medical Services guidelines target for total cholesterol, 162 (73.6% of 220) patients reached ≤5.0 mmol/L. The group that best achieved target cholesterol (Joint British Societies' Guidelines and General Medical Services) were those with comorbidities. In conclusion, while reaching General Medical Services targets was satisfactory, the percentage of patients reaching Joint British Societies' Guidelines targets was not. This discrepancy may reflect the presence of multiple guidelines. The current stricter lipid targets are difficult to achieve; possible methods that may be used to improve lipids further could involve using combination therapy, statin dose titration, and better education.

Ezetimibe-associated adverse effects: what the clinician needs to know

OBJECTIVE

Ezetimibe is a relatively new lipid lowering agent, which is indicated for the treatment of primary hypercholesterolaemia, either as monotherapy or in combination with other hypolipidaemic drugs. The objective of the present article was to review the side effects attributed to ezetimibe administration and discuss their possible underlying mechanisms. Moreover, we aimed to comment on the possible drug interactions of ezetimibe and present current guidelines regarding its safe use.

METHODS

Relevant articles were identified through a PubMed search (up to June 2007).

RESULTS

Compelling evidence from the majority of the data reviewed here showed that adverse effects associated with ezetimibe use are few and mild without having been associated with serious clinical outcomes. In most studies ezetimibe has not been associated with increased rates of myopathy or rhabdomyolysis, whether used alone or in combination with statins, although there have been some case reports of myopathy attributed to this agent. Moreover, ezetimibe has been associated with mild elevations of liver transaminases, mainly in combination with a statin. Other side effects are extremely rare. It should be noted, however, there are no long-term safety data or outcome studies for ezetimibe yet.

CONCLUSIONS

Ezetimibe is a safe alternative option for hyperlipidaemic patients intolerant to other lipid lowering drugs as well as a beneficial supplementary agent for patients who do not reach the recommended serum cholesterol level with their current hypolipidaemic treatment. However, as is the case with all new medications, physicians should be alert to recognise adverse effects associated with ezetimibe and report them to regulatory authorities.

Meta-analysis of the cholesterol-lowering effect of ezetimibe added to ongoing statin therapy

OBJECTIVE

To review and analyse the evidence for the cholesterol-lowering effect of ezetimibe in adult patients with hypercholesterolaemia who are not at low-density lipoprotein cholesterol (LDL-C) goal on statin monotherapy.

RESEARCH DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE and EMBASE were searched to identify ezetimibe randomised controlled trials (RCTs) published between January 1993 and December 2005. The meta-analysis combined data from RCTs, with a minimum treatment duration of 6 weeks, that compared treatment with ezetimibe 10 mg/day or placebo added to current statin therapy. The difference between treatments was analysed for four co-primary outcomes: mean percentage change from baseline in total cholesterol (TC), LDL-C, and high-density lipoprotein cholesterol (HDL-C), and number of patients achieving LDL-C treatment goal. Meta-analysis results are presented for a modified version of the inverse variance random effects model.

RESULTS

Five RCTs involving a total of 5039 patients were included in the meta-analysis. The weighted mean difference (WMD) between treatments significantly favoured the ezetimibe/statin combination over placebo/statin for TC (-16.1% (-17.3, -14.8); p < 0.0001), LDL-C (-23.6% (-25.6, -21.7); p < 0.0001) and HDL-C (1.7% (0.9, 2.5); p < 0.0001). The relative risk of reaching the LDL-C treatment goal was significantly higher for patients on ezetimibe/statin relative to those on placebo/statin (3.4 (2.0, 5.6); p < 0.0001). In pre-defined sub-group analyses of studies in patients with coronary heart disease, the WMD between treatments remained significantly in favour of ezetimibe/statin (p < 0.0001) for TC and LDL-C but was no longer significant for HDL-C. Elevations in creatine kinase, alanine aminotransferase or aspartate aminotransferase that were considered as an adverse effect did not differ significantly between treatments.

CONCLUSIONS

The meta-analysis we performed included only five studies and was restricted to analysis of the changes in cholesterol levels relative to baseline. However, the results suggest that ezetimibe co-administered with ongoing statin therapy provides significant additional lipid-lowering in patients not at LDL-C goal on statin therapy alone, allowing more patients to reach their LDL-C goal.

Endothelial function, arterial stiffness and lipid lowering drugs

The endothelium is a dynamic organ that plays a pivotal role in cardiovascular homeostasis. Alteration in endothelial function precedes the development of atherosclerosis and contributes to its initiation, perpetuation and clinical manifestations. It has been suggested that the assessment of endothelial function could represent a barometer of vascular health that could be used to gauge cardiovascular risk. This review summarises the various methods used to assess endothelium-dependent vasodilatation and their potential prognostic implications. In addition, the techniques used to evaluate arterial stiffness are discussed. The latter is to some extent controlled by the endothelium and has been the subject of considerable research in recent years. This paper also discusses the effects of lipid lowering treatment on both endothelial function and arterial stiffness.

Effect of ezetimibe in patients who cannot tolerate statins or cannot get to the low density lipoprotein cholesterol target despite taking a statin

BACKGROUND

Recent guidelines underline the need for high-risk patients to reach strict low density lipoprotein cholesterol (LDL-C) targets (1.8-2.6 mmol/L; 70-100 mg/dL), and specifically mention the possible use of combination therapy (e.g.statin + ezetimibe) to achieve these goals.

METHODS

A retrospective case-note audit was carried out to assess the response to administering ezetimibe in patients unable to tolerate statins (Group 1), or high dose of statins (Group 2) and patients who cannot achieve the LDL-C target (2.6 mmol/L; 100 mg/dL) despite taking a statin (Group 3).

RESULTS

Ezetimibe lowered LDL-C levels by 20-29% across the 3 patient groups after 2-3 months of treatment. High density lipoprotein cholesterol (HDL-C) levels tended to remain unchanged, although there was a consistent trend for a fall if baseline values were 'high'. However, the LDL-C/HDL-C ratio changed significantly and favourably in all groups. The fall in fasting triglyceride levels in all groups was greater (reaching 19-25%) when baseline levels were > or = 1.5 or 1.7 mmol/L (136-150 mg/dL). There were no marked abnormalities in liver function tests or creatine kinase activity. In Group 3 there was a significant trend for a fall in serum creatinine levels across the tertiles of baseline creatinine values. Limitations of the present study include the small sample size (especially in Groups 1 and 2), its short-term duration and the absence of event-based end-points. Therefore, the results are hypothesis-generating rather than conclusive.

CONCLUSIONS

When used alone or added to a statin, ezetimibe favourably altered the LDL-C/HDL-C ratio and lowered triglyceride levels. Ezetimibe was well tolerated in patients with statin intolerance and was associated with a 26% fall in LDL-C. An additional action may be some degree of improved renal function. Further studies are needed to confirm these findings.

Atorvastatin Decreases Triacylglycerol-Associated Risk of Vascular Events in Coronary Heart Disease Patients

High triacylglycerol (TAG) levels may predict vascular risk. The effect of a statin-induced reduction in TAG levels, irrespective of HDL-C increase, on clinical outcome has not yet been addressed by an endpoint study in patients with coronary heart disease (CHD). The GREACE study compared usual with structured care aimed at achieving LDL-C = 100 mg/dL (2.6 mmol/L) by dose titration with atorvastatin. All patients had CHD and were followed for 3 years. This post hoc analysis of GREACE examines the effect of statins on TAG levels and their relation with cardiovascular disease (CVD) events in all patients and in the subgroup of patients with metabolic syndrome (MetS). Baseline TAG levels >150 mg/dL (1.7 mmol/L) were predictive of subsequent CVD events [cardiac mortality, non-fatal myocardial infarction (MI), unstable angina (UA), revascularisation, congestive heart failure (CHF), and stroke] only in statin untreated patients. Stepwise regression analysis showed that with every 20% statin-related TAG reduction there was a decrease in CVD risk by 12% (HR 0.88, 95% CI 0.75-0.95, P = 0.007) in the structured care group vs. the usual care group, by 8% (HR 0.92, 95% CI 0.81-0.97, P = 0.02) in all statin treated patients vs. the untreated ones and by 15% (HR 0.85, 95% CI 0.65-0.94, P = 0.005) in those with MetS treated with a statin vs. those untreated. Using the same analysis but only taking into consideration vascular events (cardiac mortality, non-fatal MI, UA, revascularisation, and stroke) there was a 18% (HR = 0.82, 95% CI 0.57-0.96, P = 0.03) decrease in risk in the MetS (+) patients treated with a statin vs. those not on a statin, and a decrease in risk by 16% (HR = 0.84, 95% CI 0.53-1.07, P = 0.08), when only hard vascular endpoints (cardiac mortality, non-fatal MI, and stroke) were considered. TAG levels are predictive of subsequent CVD events in statin untreated CHD patients. Statin (mainly atorvastatin)-induced decrease in TAG levels was related to a significant reduction in subsequent CVD events. This benefit was more pronounced in CHD MetS (+) patients.

Should a statin be prescribed to every patient with heart failure?

Chronic heart failure (HF) represents an emerging epidemic since its prevalence is continuously increasing despite advances in treatment. Many recent clinical studies have clearly demonstrated that statin therapy is associated with improved outcomes in HF irrespective of aetiology (ischaemic or not) or baseline cholesterol levels. Indeed, most of the conducted large statin trials and trials in HF have demonstrated a positive effect of statins in HF patients. Furthermore, the use of statins in HF seems to be safe as none of the recent trials has resulted in worse outcomes for HF patients treated with statins. Potential mechanisms through which statins could benefit the failing myocardium include non-sterol effects of statins, as well as effects on nitric oxide and endothelial function, inflammation and adhesion molecules, apoptosis and myocardial remodelling and neurohormonal activation. This review discusses the pathophysiological basis of statin effects on HF and focuses on clinical data for the benefit from statin use in this setting. Until today there are no official recommendations in both the American and the European guidelines regarding the use of statins in HF patients, as the available data come from small observational or larger but retrospective, non-randomised studies. Therefore, HF patients should be treated according to current lipid guidelines. Large randomised clinical trials are underway and will further delineate the role of statin therapy in HF patients. Until more data are available, we could not recommend statin use to every patient with HF irrespective of HF aetiology and baseline cholesterol levels.

How aggressively should cholesterol targets be pursued?

Statins are universally acknowledged as one of the great successes of cardiovascular therapy in the last 25 years yet remain controversial in the popular media. Like many drugs they are under-prescribed and under-dosed in clinical practice. The statin controversy shows no sign of ending but at least it has now begun to rage over whether ‘lower is better’ when a high-dose statin is compared with a lower dose in prospective studies and in which groups of patients.

Effect of ezetimibe monotherapy on the concentration of lipoprotein subfractions in patients with primary dyslipidaemia

BACKGROUND

Recent studies suggest that the distribution of lipoprotein subfractions is an independent predictor of vascular events. Therefore, we evaluated the effect of ezetimibe (a selective cholesterol transport inhibitor) on the concentrations of lipoprotein subfractions in patients with primary dyslipidaemia.

MATERIALS AND METHODS

Patients (n = 50) with primary dyslipidaemias were recruited. The concentrations of the individual lipoprotein subfractions were measured using the Lipoprint system at baseline and after 16 weeks of treatment.

RESULTS

Ezetimibe reduced total, low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (HDL-C) values as well as apolipoprotein B concentrations. Subfractionation of apolipoprotein B-containing lipoproteins showed that the reduction in LDL-C values was due to a fall in the concentrations of all LDL subfractions. However, a more pronounced trend towards a decrease in the concentrations of dense LDL subfractions was observed. Patients with triglyceride values >1.7 mmol/L had significantly greater reductions in the concentrations of small, dense LDL particles compared with those with normal triglyceride levels (49 vs. 19%, respectively; p < 0.05). Ezetimibe decreased the concentrations of HDL-C mainly due to a fall in the concentration of dense HDL subfractions.

CONCLUSION

Ezetimibe can favourably affect the distribution of LDL subfractions, especially in patients with elevated triglyceride values. Further studies are needed to clarify the significance of the ezetimibe-induced reduction in the concentrations of dense HDL particles.

Microemulsions as carriers for drugs and nutraceuticals

Microemulsions are potentially excellent carriers for bioactive molecules. They offer the advantage of spontaneous formation, ease of manufacture, thermodynamic stability, and improved solubilization of bioactive materials. This review explores some of the new trends in microemulsion research through analysis of some representative studies. The solubilization of different classic drugs, peptides, and nutraceuticals in various oral microemulsion compositions and microstructures was reviewed. It was found that even W/O microemulsions, which are expected to break upon dilution in the digestive tract, increase the permeability and bioavailability of drugs. Thus, it seems that component selection (the use of molecules that can act as permeability enhancers) is of great importance. Structures such as self-microemulsifying drug delivery systems (SMEDDS), W/O, bicontinuous, and O/W microemulsions, were closely examined, and their potential to serve as drug carriers was evaluated. It seems that for microemulsion systems to be used as vehicles for bioactive materials, the formulations should be based on SMEEDS, which form O/W upon dilution to a specific water content. U-type microemulsions are actually an improved SMEDDS formulation, capable of being diluted with any given water concentration. Much research is being conducted on microemulsion microstructure since there is an obvious direct connection between the microstructure, solubilization capacity, and bioavailability of the active molecules.

Cytochrome P450s and cholesterol homeostasis

By participating in pathways of cholesterol biosynthesis and elimination, different cytochrome P450 (P450 or CYP) enzymes play an important role in maintenance of cholesterol homeostasis. CYP51 is involved in cholesterol biosynthesis, whereas CYP 7A1, 27A1, 46A1, 7B1, 39A1, and 8B1 are the key enzymes in cholesterol catabolism to bile acids, the major route of cholesterol elimination in mammals. Cholesterol transformations to steroid hormones are also initiated by the P450 enzyme CYP11A1. Finally, one of the major drug-metabolizing P450s CYP3A4 seems to contribute to bile acid biosynthesis as well. The 9 P450s will be the focus of this review and assessed as drug targets for cholesterol lowering.

Non-low-density lipoprotein cholesterol-associated actions of ezetimibe: an overview

Ezetimibe, an intestinal cholesterol absorption inhibitor, lowers circulating low-density lipoprotein cholesterol (LDL-C) levels both when administered as monotherapy and in combination with other hypolipidaemic drugs, mostly statins. This review focuses on the effects of ezetimibe on non-LDL-C-associated variables. In most studies, ezetimibe effectively reduced triglyceride and increased high density lipoprotein cholesterol levels. The authors also consider the effect of ezetimibe on other variables such as C-reactive protein levels, insulin sensitivity and endothelial function. Ezetimibe is useful in patients with sitosterolaemia (a rare inherited disorder) as it significantly reduces plasma phytosterol concentrations. Ezetimibe fulfils two of the three essential characteristics of any drug (efficacy and safety). However, clinical studies are required to provide evidence of its ability to reduce vascular events.

Ezetimibe/simvastatin single tablet versus rosuvastatin in patients with hypercholesterolemia

Recent guidelines recommend strict goals for low density lipoprotein cholesterol (LDL-C) (70-100 mg/dL; 1.8-2.6 mmol/L). These goals were set following the publication of several trials. In the current issue of the journal, a study compares different doses of the combination tablet (ezetimibe/simvastatin) with statin monotherapy (rosuvastatin). In keeping with previous literature, the combination therapy was more effective in achieving LDL-C goals. This editorial comments on the potential disadvantages of using monotherapy with high-dose statins and considers the issue of statin-induced proteinuria. Combination therapy may need to be increasingly used to achieve the LDL-C targets set by recent guidelines.