Update on the efficacy and safety of combination ezetimibe plus statin therapy

Combined use of rosuvastatin and ezetimibe improves hepatic steatosis in patients with dyslipidemia

BACKGROUND AND AIMS

Rosuvastatin plus ezetimibe are beneficial for the management of dyslipidemia. We investigated whether rosuvastatin plus ezetimibe improves hepatic steatosis in patients with dyslipidemia.

METHODS

Between January and August 2018, 114 patients with dyslipidemia treated for 6 months with rosuvastatin plus ezetimibe were analyzed in this retrospective cohort study. The degree of hepatic steatosis was assessed using the hepatic steatosis index (HSI). Hepatic steatosis improvement and presence of fatty liver were defined as a ≥5% reduction in HSI score and HSI ≥36, respectively.

RESULTS

The mean age of the study population (50 males and 64 females) was 57.4 years. At baseline, the mean BMI total cholesterol level, low-density lipoprotein cholesterol level, high-density lipoprotein cholesterol level, triglyceride level, and HSI were 25.1 kg/m, 207.4 mg/dL, 126.1 mg/dL, 52.9 mg/dL, 146.4 mg/dL, and 36.1, respectively. During the 6-month treatment, hepatic steatosis burden was constant (mean HSI = 36.3 and 36.4 at 3 and 6 months, respectively). On multivariate analyses, ultrasonographic fatty liver and HSI ≥36 were selected as independent predictors of hepatic steatosis improvement. However, when 53 (46.5%) patients with fatty liver (HSI ≥ 36) were selected, hepatic steatosis burden was significantly improved (mean HSI = 40.8, 39.3, and 39.7 at baseline, 3 months, and 6 months, respectively).

CONCLUSIONS

The use of rosuvastatin plus ezetimibe for the management of dyslipidemia did not improve hepatic steatosis burden in all patients with dyslipidemia, but it improved hepatic steatosis burden in the subgroup with fatty liver.

Diet and Nutraceutical Supplementation in Dyslipidemic Patients: First Results of an Italian Single Center Real-World Retrospective Analysis

Background: Dyslipidemias are a heterogeneous group of metabolic disorders mainly characterized by an increased risk of atherosclerotic cardiovascular disease (ASCVD) or other conditions, such as acute pancreatitis in hypertriglyceridemia. The aim of this study was to evaluate the effect of diet treatment and nutraceutical (NUTs) supplementation on the plasma lipid profile in outpatient dyslipidemic subjects, considering the influence of several factors (i.e., gender, age, body mass index, alcohol consumption, and smoking habits). Methods: 487 dyslipidemic patients spanning from 2015 to 2019 were treated with a Mediterranean diet or NUTs in a real-word setting and were retrospectively analyzed. General characteristics and lipid profile at baseline and after the follow-up period were evaluated. Results: Diet alone reduced total cholesterol (−19 mg/dL, −7.7%), LDL cholesterol (−18 mg/dL, −10.1%), and triglycerides (−20 mg/dL, −16.7%). Triglycerides (TG) decreased more in men, while women were associated with higher reduction of LDL cholesterol (LDL-C). Different types of NUTs further ameliorate lipid profiles when associated with diet. Nevertheless, most patients at low ASCVD risk (222 out of 262, 81.6%) did not achieve the 2019 ESC/EAS guidelines recommended LDL-C goals (i.e., LDL-C < 116 mg/dL). Conclusion: Lipid-lowering diet improves lipid profile, and NUTs can boost its efficacy, but taken together they are mainly unsatisfactory with respect to the targets imposed by 2019 EAS/ESC guidelines.

Significant effect of simvastatin and/or ezetimibe-loaded nanofibers on the healing of femoral defect: An experimental study

BACKGROUND

Fracture healing complications are associated with significant healthcare and economic burden. In this study, we aimed to investigate how the combined administration of local simvastatin and ezetimibe into the femoral defect of the animal model affects the bone-healing process in comparison with their monotherapy.

METHODS

A total of 32 four-month-old adult male Wistar rats were randomized into the four study groups: simvastatin + ezetimibe-loaded nanofibers (group 1), simvastatin-loaded nanofibers (group 2), ezetimibe-loaded nanofibers (group 3), and non-loaded nanofibers (group 4). After the generation of femoral defects, the predesigned nanofibers were locally administered into the defect site. The healing measures were serum and bone osteoprotegerin (OPG) expression, pathologic evaluation of union (Allen's fracture healing scores), and radiographic evaluation of bone density (Hounsfield scale) at weeks 2 and 4.

RESULTS

The improvement of all evaluated healing measures was remarkably superior in rats that were treated with loaded nanofibers in comparison with the control group. Also, the improvement of all evaluated healing measures was considerably more in the simvastatin-ezetimibe combination therapy group compared to their monotherapy. All the evaluated measures were superior in the ezetimibe monotherapy group compared to the simvastatin monotherapy group.

CONCLUSION

The cumulative effect of simvastatin and ezetimibe on the induction of bone healing is more significant than the individual effect of these drugs. Therefore, local administration of nanofibers loaded with simvastatin and ezetimibe could be regarded as a promising osteoinductive compound for the acceleration of bone repair.

New Perspectives on Atherogenic Dyslipidaemia and Cardiovascular Disease

Over the past few decades, atherogenic dyslipidaemia has become one of the most common phenotypic presentations of lipid abnormalities, being strongly and unequivocally associated with an increased risk of cardiovascular (CV) disease. Despite the excellent results achieved from statin and non-statin management of LDL cholesterol and CV events prevention, there still remains a significant residual risk, associated with the prevalence of non-LDL cholesterol lipid patterns characterised by elevated triglyceride levels, low HDL cholesterol, a preponderance of small and dense LDL particles, accumulation of remnant lipoproteins and postprandial hyperlipidaemia. These qualitative and quantitative lipid modifications are largely associated with insulin resistance, type 2 diabetes and obesity, the prevalence of which has grown to epidemic proportions throughout the world. In this review, we analyse the pathophysiology of this particular dyslipidaemia, its relationship with the development of atherosclerotic CV disease and, finally, briefly describe the therapeutic approaches, including changes in lifestyle and current pharmacological interventions to manage these lipid alterations aimed at preventing CV events.

Lunasin Improves the LDL-C Lowering Efficacy of Simvastatin via Inhibiting PCSK9 Expression in Hepatocytes and ApoE-/- Mice

Statins are the most popular therapeutic drugs to lower plasma low density lipoprotein cholesterol (LDL-C) synthesis by competitively inhibiting hydroxyl-3-methyl-glutaryl-CoA (HMG-CoA) reductase and up-regulating the hepatic low density lipoprotein receptor (LDLR). However, the concomitant up-regulation of proprotein convertase subtilisin/kexin type 9 (PCSK9) by statin attenuates its cholesterol lowering efficacy. Lunasin, a soybean derived 43-amino acid polypeptide, has been previously shown to functionally enhance LDL uptake via down-regulating PCSK9 and up-regulating LDLR in hepatocytes and mice. Herein, we investigated the LDL-C lowering efficacy of simvastatin combined with lunasin. In HepG2 cells, after co-treatment with 1 μM simvastatin and 5 μM lunasin for 24 h, the up-regulation of PCSK9 by simvastatin was effectively counteracted by lunasin via down-regulating hepatocyte nuclear factor 1α (HNF-1α), and the functional LDL uptake was additively enhanced. Additionally, after combined therapy with simvastatin and lunasin for four weeks, ApoE^−/− mice had significantly lower PCSK9 and higher LDLR levels in hepatic tissues and remarkably reduced plasma concentrations of total cholesterol (TC) and LDL-C, as compared to each monotherapy. Conclusively, lunasin significantly improved the LDL-C lowering efficacy of simvastatin by counteracting simvastatin induced elevation of PCSK9 in hepatocytes and ApoE^−/− mice. Simvastatin combined with lunasin could be a novel regimen for hypercholesterolemia treatment.

Statin combination therapy and cardiovascular risk reduction

In numerous clinical trials, lowering LDL-C with statin therapy has been demonstrated to reduce the risk of cardiovascular disease (CVD) in primary and secondary prevention settings. Guidelines recommend statins for first-line therapy in cholesterol-lowering management of patients with CVD risk. Despite increased statin monotherapy use over the last decade, a number of patients with high CVD risk do not achieve optimal LDL-C lowering. Guidelines recommend consideration of statin combination therapy with nonstatin agents for these patients. However, combination therapy approaches have been hampered by neutral findings. Recently, ezetimibe added to simvastatin therapy reduced cardiovascular events in acute coronary syndrome patients, more than simvastatin alone. This article provides an overview of various agents in combination with statin therapy on cardiovascular outcomes. Other lipid-lowering agents in development, including PCSK9 and CETP inhibitors in development, are also described.

Effect of Switching From Statin Monotherapy to Ezetimibe/Simvastatin Combination Therapy Compared With Other Intensified Lipid-Lowering Strategies on Lipoprotein Subclasses in Diabetic Patients With Symptomatic Cardiovascular Disease

Background

Patients with diabetes mellitus and cardiovascular disease may not achieve adequate low‐density lipoprotein cholesterol (LDL‐C) lowering on statin monotherapy, attributed partly to atherogenic dyslipidemia. More intensive LDL‐C–lowering therapy can be considered for these patients. A previous randomized, controlled study demonstrated greater LDL‐C lowering in diabetic patients with symptomatic cardiovascular disease who switched from simvastatin 20 mg (S20) or atorvastatin 10 mg (A10) to combination ezetimibe/simvastatin 10/20 mg (ES10/20) therapy, compared with statin dose‐doubling (to S40 or A20) or switching to rosuvastatin 10 mg (R10). The effect of these regimens on novel biomarkers of atherogenic dyslipidemia (low‐ and high‐density lipoprotein particle number and lipoprotein‐associated phospholipase A2 [Lp‐PLA₂]) was assessed.

Methods and Results

Treatment effects on low‐ and high‐density lipoprotein particle number (by NMR) and Lp‐PLA₂ (by ELISA) were evaluated using plasma samples available from 358 subjects in the study. Switching to ES10/20 reduced low‐density lipoprotein‐particle number numerically more than did statin dose‐doubling and was comparable with R10 (−133.3, −94.4, and −56.3 nmol/L, respectively; P>0.05). Increases in high‐density lipoprotein particle number were significantly greater with switches to ES10/20 versus statin dose‐doubling (1.5 and −0.5 μmol/L; P<0.05) and comparable with R10 (0.7 μmol/L; P>0.05). Percentages of patients attaining low‐density lipoprotein particle number levels <990 nmol/L were 62.4% for ES10/20, 54.1% for statin dose‐doubling, and 57.0% for R10. Switching to ES10/20 reduced Lp‐PLA₂ activity significantly more than did statin dose‐doubling (−28.0 versus −3.8 nmol/min per mL, P<0.05) and was comparable with R10 (−28.0 versus −18.6 nmol/min per mL; P>0.05); effects on Lp‐PLA₂ concentration were modest.

Conclusions

In diabetic patients with dyslipidemia, switching from statins to combination ES10/20 therapy generally improved lipoprotein subclass profile and Lp‐PLA₂ activity more than did statin dose‐doubling and was comparable with R10, consistent with its lipid effects.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00862251.

Efficacy and safety of ezetimibe monotherapy in children with heterozygous familial or nonfamilial hypercholesterolemia

OBJECTIVES

To evaluate the lipid-altering efficacy and safety of ezetimibe monotherapy in young children with heterozygous familial hypercholesterolemia (HeFH) or nonfamilial hypercholesterolemia (nonFH).

STUDY DESIGN

One hundred thirty-eight children 6-10 years of age with diagnosed HeFH or clinically important nonFH (low-density lipoprotein cholesterol [LDL-C] ≥ 160 mg/dL [4.1 mmol/L]) were enrolled into a multicenter, 12-week, randomized, double-blind, placebo-controlled study. Following screening/drug washout and a 5-week single-blind placebo-run-in with diet stabilization, subjects were randomized 2:1 to daily ezetimibe 10 mg (n = 93) or placebo (n = 45) for 12 weeks. Lipid-altering efficacy and safety were assessed in all treated patients.

RESULTS

Overall, mean age was 8.3 years, 57% were girls, 80% were white, mean baseline LDL-C was 228 mg/dL (5.9 mmol/L), and 91% had HeFH. After 12 weeks, ezetimibe significantly reduced LDL-C by 27% after adjustment for placebo (P < .001) and produced significant reductions in total cholesterol (21%), nonhigh-density lipoprotein cholesterol (26%), and apolipoprotein B (20%) (P < .001 for all). LDL-C lowering response in sex, race, baseline lipids, and HeFH/nonFH subgroups was generally consistent with overall study results. Ezetimibe was well tolerated, with a safety profile similar to studies in older children, adolescents, and adults.

CONCLUSIONS

Ezetimibe monotherapy produced clinically relevant reductions in LDL-C and other key lipid variables in young children with primary HeFH or clinically important nonFH, with a favorable safety/tolerability profile.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00867165.

Achieving goal lipid levels with ezetimibe plus statin add-on or switch therapy compared with doubling the statin dose. A pooled analysis

OBJECTIVE

Evaluate the lipid-altering effects of ezetimibe added to ongoing statin therapy, statin titration, switching from statin monotherapy to a more potent statin or to ezetimibe/simvastatin.

METHODS

A pooled analysis of patient-level data from 17 double-blind, active or placebo-controlled studies of 8667 hypercholesterolemic adults randomized to ezetimibe 10 mg added to ongoing statins, statin titration (doubling), or switching from ongoing statins to rosuvastatin (10 mg) or to ezetimibe/simvastatin (10/20 and 40 mg). Percent change from baseline in low-density lipoprotein cholesterol (LDL-C) was estimated by analysis of variance. Percent of patients who achieved LDL-C and other guideline-recommended targets, and target lipid levels by baseline distance to goal were evaluated.

RESULTS

LDL-C percent change from baseline was -26.0 for ezetimibe added to ongoing statin therapy, -27.6 for switching from ongoing statin to ezetimibe/simvastatin, -19.7 for switching to rosuvastatin 10 mg, and -9.7 for dose doubling of the ongoing statin. For patients within 0.8 mmol/L (30 mg/dL) of the target at baseline, LDL-C target attainment rates were 75.9% for adding ezetimibe to ongoing statin, 72.8% for switching to ezetimibe/simvastatin, 61.8% for switching to rosuvastatin, and 44.3% for statin dose-doubling. Similarly, improvements in other lipids and achievement of non-high-density lipoprotein cholesterol and apolipoprotein B targets among this patient group were largest for ezetimibe added to ongoing statins and switching to ezetimibe/simvastatin; switching to rosuvastatin 10 mg and statin dose-doubling were less effective.

CONCLUSIONS

Adding ezetimibe to ongoing statin therapy appeared to be an effective option for patients who do not achieve lipid-lowering goals on statins alone.

Evaluating cardiovascular event reduction with ezetimibe as an adjunct to simvastatin in 18,144 patients after acute coronary syndromes: final baseline characteristics of the IMPROVE-IT study population

BACKGROUND

The IMProved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) is evaluating the potential benefit for reduction in major cardiovascular (CV) events from the addition of ezetimibe versus placebo to 40 mg/d of simvastatin therapy in patients who present with acute coronary syndromes and have low-density lipoprotein cholesterol (LDL-C) ≤ 125 mg/dL.

METHODS

The primary composite end point is CV death, nonfatal myocardial infarction (MI), nonfatal stroke, rehospitalization for unstable angina (UA), and coronary revascularization (≥ 30 days postrandomization). The simvastatin monotherapy arm's LDL-C target is <70 mg/dL. Ezetimibe was assumed to further lower LDL-C by 15 mg/dL and produce an estimated ~8% to 9% treatment effect. The targeted number of events is 5,250.

RESULTS

We enrolled 18,144 patients with either ST-segment elevation MI (STEMI, n = 5,192) or UA/non-ST-segment elevation MI (UA/NSTEMI, n = 12,952) from October 2005 to July 2010. Western Europe (40%) and North America (38%) were the leading enrolling regions. The STEMI cohort was younger and had a higher percentage of patients naive to lipid-lowering treatment compared with the UA/NSTEMI cohort. The UA/NSTEMI group had a higher prevalence of diabetes, hypertension, and prior MI. Median LDL-C at entry was 100 mg/dL for STEMI and 93 mg/dL for UA/NSTEMI patients.

CONCLUSIONS

This trial is evaluating LDL-C lowering beyond previously targeted LDL-C levels. The results depend on achieving the desired separation of LDL-C with ezetimibe and on the assumption that ezetimibe's lowering of LDL-C will have similar event reduction efficacy as the LDL-C lowering from a statin. The results could affect future therapies and guidelines.

Efficacy and safety of ezetimibe added to atorvastatin versus atorvastatin uptitration or switching to rosuvastatin in patients with primary hypercholesterolemia

Hypercholesterolemic patients (n = 1,547) at high atherosclerotic cardiovascular disease risk with low-density lipoprotein cholesterol (LDL-C) levels ≥100 and ≤160 mg/dl while treated with atorvastatin 10 mg/day entered a multicenter, randomized, double-blind, active-controlled, clinical trial using two 6-week study periods. Period I compared the efficacy/safety of (1) adding ezetimibe 10 mg (ezetimibe) to stable atorvastatin 10 mg, (2) doubling atorvastatin to 20 mg, or (3) switching to rosuvastatin 10 mg. Subjects in the latter 2 groups who persisted with elevated LDL-C levels (≥100 and ≤160 mg/dl) after period I, entered period II; subjects on atorvastatin 20 mg had ezetimibe added to their atorvastatin 20 mg, or uptitrated their atorvastatin to 40 mg; subjects on rosuvastatin 10 mg switched to atorvastatin 20 mg plus ezetimibe or uptitrated their rosuvastatin to 20 mg. Some subjects on atorvastatin 10 mg plus ezetimibe continued the same treatment into period II. At the end of period I, ezetimibe plus atorvastatin 10 mg reduced LDL-C significantly more than atorvastatin 20 mg or rosuvastatin 10 mg (22.2% vs 9.5% or 13.0%, respectively, p <0.001). At the end of period II, ezetimibe plus atorvastatin 20 mg reduced LDL-C significantly more than atorvastatin 40 mg (17.4% vs 6.9%, p <0.001); switching from rosuvastatin 10 mg to ezetimibe plus atorvastatin 20 mg reduced LDL-C significantly more than uptitrating to rosuvastatin 20 mg (17.1% vs 7.5%, p <0.001). Relative to comparative treatments, ezetimibe added to atorvastatin 10 mg (period I) or atorvastatin 20 mg (period II) produced significantly greater percent attainment of LDL-C targets <100 or <70 mg/dl, and significantly greater percent reductions in total cholesterol, non-high-density lipoprotein cholesterol, most lipid and lipoprotein ratios, and apolipoprotein B (except ezetimibe plus atorvastatin 20 vs atorvastatin 40 mg). Reports of adverse experiences were generally similar among groups. In conclusion, treatment of hypercholesterolemic subjects at high cardiovascular risk with ezetimibe added to atorvastatin 10 or 20 mg produced significantly greater improvements in key lipid parameters and significantly greater attainment of LDL-C treatment targets than doubling atorvastatin or switching to (or doubling) rosuvastatin at the compared doses.

Therapeutic practice patterns related to statin potency and ezetimibe/simvastatin combination therapies in lowering LDL-C in patients with high-risk cardiovascular disease

BACKGROUND

Statin combination therapy and statin uptitration have been shown to be efficacious in low-density lipoprotein cholesterol (LDL-C) lowering and are recommended for patients with high-risk coronary heart disease (CHD) who do not reach guideline-endorsed LDL-C goals on statin monotherapy.

OBJECTIVE

This analysis evaluated treatment practice patterns and LDL-C lowering for patients with CHD/CHD risk equivalent on statin monotherapy in a real-world practice setting in the United States.

METHODS

In this retrospective, observational study, patients with CHD/CHD risk equivalent on statin therapy were identified during 2004 to 2008 in a US managed care database. Prescribing patterns and effect of switching from statin monotherapy to combination ezetimibe/simvastatin therapy vs uptitration to higher statin dose/potency level and no change from initial statin potency on LDL-C lowering were assessed. Percentage of change from baseline in LDL-C levels and odds ratios for LDL-C goal attainment were estimated with analyses of covariance and logistic regression.

RESULTS

Of 27,919 eligible patients on statin therapy, 2671 (9.6%) switched to ezetimibe/simvastatin therapy, 11,035 (39.5%) uptitrated statins, and 14,213 (50.9%) remained on the same statin monotherapy. LDL-C reduction from baseline and attainment of LDL-C <100 and <70 mg/dL were substantially greater for patients who switched to ezetimibe/simvastatin therapy (-24.0%, 81.2%, and 35.2%, respectively) than for patients who titrated (-9.6%, 68.0%, and 18.4%, respectively) or remained on initial statin therapy (4.9%, 72.2%, and 23.7%, respectively). The odds ratios for attainment of LDL-C <100 and <70 mg/dL were also higher for patients who switched than for patients who uptitrated and had no therapy change than for patients who titrated vs no therapy change. Similarly, among a subgroup of patients not at LDL-C <100 mg/dL on baseline therapy, attainment of LDL-C <100 and <70 mg/dL was greater for patients who switched than for statin uptitration vs no change, as well as for patients who uptritrated statins vs no therapy change.

CONCLUSION

In this study, LDL-C lowering and goal attainment rates improved substantially for patients with high-risk CHD on statin monotherapy who switched to combination ezetimibe/statin or uptitrated their statin therapies; however, approximately one-third of these patients still did not attain the optional recommended LDL-C goal of <70 mg/dL. Moreover, these higher efficacy lipid-lowering therapies were infrequently prescribed, indicating the need for further assessment of barriers to LDL-C goal attainment in actual practice settings.

Changes in lipoprotein particle number with ezetimibe/simvastatin coadministered with extended-release niacin in hyperlipidemic patients

Background

Combination therapy with ezetimibe/simvastatin (E/S) and extended‐release niacin (N) has been reported to be safe and efficacious in concomitantly reducing low‐density lipoprotein cholesterol and increasing high‐density lipoprotein cholesterol in hyperlipidemic patients at high risk for atherosclerotic cardiovascular events. This analysis evaluated the effect of E/S coadministered with N on low‐density lipoprotein particle number (LDL‐P) and high‐density lipoprotein particle number (HDL‐P) as assessed by nuclear magnetic resonance (NMR) spectroscopy in patients with type IIa or IIb hyperlipidemia.

Methods and Results

This was an analysis of a previously reported 24‐week randomized, double‐blind study in type IIa/IIb hyperlipidemic patients randomized to treatment with E/S (10/20 mg/day)+N (titrated to 2 g/day) or N (titrated to 2 g/day) or E/S (10/20 mg/day). Samples from a subset of patients (577 of 1220) were available for post hoc analysis of LDL‐P and HDL‐P by NMR spectroscopy. Increases in HDL‐P (+16.2%) and decreases in LDL‐P (−47.7%) were significantly greater with E/S+N compared with N (+9.8% for HDL‐P and −21.5% for LDL‐P) and E/S (+12.8% for HDL‐P and −36.8% for LDL‐P). In tertile analyses, those with the lowest baseline HDL‐P had the greatest percent increase in HDL‐P (N, 18.4/7.9/2.1; E/S, 19.3/12.2/5.3; and E/S+N, 26.9/13.8/6.9; all P<0.001). Individuals in the highest tertile of LDL‐P had the greatest percent reduction in LDL‐P (N, 18.3/23.1/24.6; E/S, 29.7/38.3/41.8; and E/S+N, 44.3/49.0/50.5; all P<0.001).

Conclusions

These results suggest that E/S+N improves lipoprotein particle number, consistent with its lipid‐modifying benefits in type IIa or IIb hyperlipidemia patients and may exert the greatest effect in those with high LDL‐P and low HDL‐P at baseline.

Clinical Trial Registration

URL: Clinicaltrials.gov Identifier: NCT00271817

Ezetimibe/simvastatin 10/40 mg versus atorvastatin 40 mg in high cardiovascular risk patients with primary hypercholesterolemia: a randomized, double-blind, active-controlled, multicenter study

Background

A considerable number of patients with severely elevated LDL-C do not achieve recommended treatment targets, despite treatment with statins. Adults at high cardiovascular risk with hypercholesterolemia and LDL-C ≥ 2.59 and ≤ 4.14 mmol/L (N = 250), pretreated with atorvastatin 20 mg were randomized to ezetimibe/simvastatin 10/40 mg or atorvastatin 40 mg for 6 weeks. The percent change in LDL-C and other lipids was assessed using a constrained longitudinal data analysis method with terms for treatment, time, time-by-treatment interaction, stratum, and time-by-stratum interaction. Percentage of subjects achieving LDL-C < 1.81 mmol/L, < 2.00 mmol/L, or < 2.59 mmol/L was assessed using a logistic regression model with terms for treatment and stratum. Tolerability was assessed.

Results

Switching to ezetimibe/simvastatin resulted in significantly greater changes in LDL-C (-26.81% vs.-11.81%), total cholesterol (-15.97% vs.-7.73%), non-HDL-C (-22.50% vs.-10.88%), Apo B (-17.23% vs.-9.53%), and Apo A-I (2.56% vs.-2.69%) vs. doubling the atorvastatin dose (all p ≤ 0.002), but not HDL-C, triglycerides, or hs-CRP. Significantly more subjects achieved LDL-C < 1.81 mmol/L (29% vs. 5%), < 2.00 mmol/L (38% vs. 9%) or < 2.59 mmol/L (69% vs. 41%) after switching to ezetimibe/simvastatin vs. doubling the atorvastatin dose (all p < 0.001). The overall safety profile appeared generally comparable between treatment groups.

Conclusions

In high cardiovascular risk subjects with hypercholesterolemia already treated with atorvastatin 20 mg but not at LDL-C < 2.59 mmol/L, switching to combination ezetimibe/simvastatin 10/40 mg provided significantly greater LDL-C lowering and greater achievement of LDL-C targets compared with doubling the atorvastatin dose to 40 mg. Both treatments were generally well-tolerated.

Trial registration

Registered at clinicaltrials.gov: NCT00782184

Intestinal sterol transporters and cholesterol absorption inhibition

PURPOSE OF REVIEW

Statin therapy is the mainstay of lipid-lowering therapy; however, many patients, particularly those at high risk, do not achieve sufficient LDL-cholesterol (LDL-C) lowering. Thus, there remains an unmet medical need for more effective and well tolerated lipid-lowering agents. Guidelines recommend combining additional lipid-lowering agents with a complementary mode of action for these patients. One approach to complementing statin therapy is combination with inhibitors that block the intestinal absorption of dietary and biliary cholesterol. This review summarizes what is currently known about intestinal sterol transporters and cholesterol absorption inhibitors (CAIs).

RECENT FINDINGS

The only lipid-lowering agent currently available that specifically targets an intestinal sterol transporter (Niemann-Pick C1-like 1) is the CAI, ezetimibe. It is effective in lowering LDL-C, both when given alone and when combined with a statin. Clinical outcome data with ezetimibe combined with simvastatin have recently become available, and definitive evidence that the incremental LDL-C lowering attributable to the ezetimibe component reduces cardiovascular events beyond simvastatin alone is currently under study. Other novel CAIs have been evaluated based upon the structure and properties of ezetimibe, but none remain in development.

SUMMARY

Additional lipid-lowering agents are needed to fulfill an unmet medical need for those patients who do not achieve optimal LDL-C goals on statin monotherapy. The inhibition of cholesterol absorption is an important therapeutic strategy to reduce cholesterol levels. Based upon the demonstrated lipid-altering efficacy and safety of ezetimibe, several CAIs have been identified; all to date have been discontinued due to limited efficacy.

The ezetimibe controversy: implications for clinical practice

Low-density lipoprotein cholesterol (LDL-C) remains the primary target of lipid-lowering therapy. Achieving LDL-C goals as outlined by the National Cholesterol Education Program Adult Treatment Panel III can be difficult with statins alone; therefore, adjunctive therapy is often indicated to reduce cardiovascular risk. Ezetimibe, a potent inhibitor of intestinal cholesterol absorption, has been shown to be safe, tolerable and effective at lowering LDL-C, non-high-density lipoprotein cholesterol and apolipoprotein B, each of which has been correlated with improved clinical outcomes, alone or in combination with a statin. However, because of randomized trials that demonstrated mixed results about atherosclerotic plaque regression via carotid intima-media thickness and a concern about cancer risk, ezetimibe's role in lipid therapy has been questioned. Currently, a large randomized controlled trial is in progress to answer if ezetimibe improves clinical outcomes in patients with high-risk acute coronary syndrome. A smaller trial in patients with chronic kidney disease demonstrated reduced clinical events, including myocardial infarction, stroke and revascularization for patients taking the combination of ezetimibe and simvastatin versus those taking statin or placebo alone. In this paper, we review the trials that have led to the ezetimibe controversy and then discuss the possible role of ezetimibe in specific patient populations until the results of ongoing clinical trials are known.