Statin Therapy Alters the Relationship Between Apolipoprotein B and Low-Density Lipoprotein Cholesterol and Non–High-Density Lipoprotein Cholesterol Targets in High-Risk Patients

Predictive value of remnant lipoprotein for cardiovascular events in patients with coronary artery disease after achievement of LDL-cholesterol goals

OBJECTIVES

Triglycerides-rich lipoproteins are related to residual cardiovascular risk in patients on lipid-lowering treatment who achieve low-density lipoprotein cholesterol (LDL-C) goals. This study examined the predictive value of remnant lipoprotein levels for cardiovascular events in patients with coronary artery disease (CAD) with LDL-C levels <100mg/dL on lipid-lowering therapy.

METHODS

Serum levels of remnant lipoproteins (remnant-like lipoprotein particles cholesterol; RLP-C) were measured by an immunoseparation method in 560 patients with CAD who had LDL-C levels <100mg/dL on lipid-lowering therapy, including statin (58%), fibrate (13%) or diet only (29%). All the patients were followed prospectively for a period of ≤ 36 months or until occurrence of one of the following events: cardiac death, non fatal myocardial infarction, unstable angina requiring coronary revascularization, or ischemic stroke.

RESULTS

During a mean follow-up period of 33 months, 40 events occurred. Stepwise multivariate Cox proportional hazard analysis showed that RLP-C was a significant predictor of cardiovascular events after adjustment for known risk factors and lipid variables including triglycerides, non-high-density lipoprotein (HDL)-C, and total apolipoprotein B (HR 1.53, 95% CI 1.35-1.97, p<0.01). The c-statistics showed that addition of RLP-C had a greater incremental effect on the predictive value of conventional risk factors than addition of non-HDL-C or total apolipoprotein B.

CONCLUSIONS

RLP-C was superior to non-HDL-C for predicting cardiovascular events in CAD patients with LDL-C levels <100mg/dL on lipid-lowering treatment. Remnant lipoprotein may therefore be an important target for residual risk reduction after LDL-C goals on lipid lowering therapy.

Influence of simvastatin, fenofibrate and/or ezetimibe on correlation of low-density lipoprotein and nonhigh-density lipoprotein cholesterol with apolipoprotein B in mixed dyslipidemic patients

OBJECTIVES

Correlations between low-density lipoprotein cholesterol (LDL-C), or nonhigh-density lipoprotein cholesterol (non-HDL-C) and apolipoprotein B (Apo B) change after statin therapy has been initiated in hypercholesterolemic patients. This post-hoc analysis studied the correlation between these parameters in patients with mixed dyslipidemia before and after receiving lipid-lowering treatment.

RESULTS

Data from two randomized, double-blind studies of 1112 patients with mixed dyslipidemia receiving treatment (ezetimibe 10 mg, ezetimibe/simvastatin 10/20 mg, fenofibrate 160 mg, ezetimibe + fenofibrate 10/160 mg, or ezetimibe/simvastatin + fenofibrate 10/20/160 mg) were pooled. Correlation analyses and simple linear regression analyses were performed at baseline in untreated patients and after 12 weeks of treatment in the whole pooled population, the treatment groups, and after stratification by baseline triglyceride levels (150-250, ≥ 250 mg/dL) within the treatment groups. Both LDL-C and non-HDL-C were closely correlated with levels of Apo B at baseline, and these correlations improved after treatment. When using the fitted simple linear regression equations, we found that the on-treatment LDL-C and non-HDL-C levels corresponding to an Apo B of 90, 80, and 70 mg/dL were lower than proposed LDL-C and non-HDL-C treatment targets. For TG ≥ 250 mg/dL, the corresponding LDL-C was generally lower than that for triglycerides 150-250 mg/dL, except in the cases with fenofibrate in the treatment.

CONCLUSION

The results of these analyses suggest that achieving goal-specified levels of Apo B in statin-treated patients with mixed dyslipidemia would require more aggressive LDL-C lowering to achieve the greatest reduction in LDL particle number.

LDL cholesterol goals and cardiovascular risk during statin treatment: the IDEAL study

AIMS

We assessed the proportion of patients treated with either simvastatin 20 or 40 mg or atorvastatin 80 mg who achieved low-density lipoprotein cholesterol (LDL-C) goals of 2.5 or 2.0 mmol/l in the Incremental Decrease in End Points Through Aggressive Lipid Lowering (IDEAL) study. We explored how lipoprotein components related to cardiovascular disease (CVD) outcomes in these groups.

METHODS AND RESULTS

For subjects who reached on-treatment LDL-C goals, Cox regression models were used to assess the ability of lipoprotein components to predict CVD events. Treatment with simvastatin or atorvastatin resulted in 40 per cent and 80 per cent of patients, respectively, reaching the 2.5 mmol/l goal and 12 per cent and 52 per cent, respectively, reaching the 2.0 mmol/l goal, after 1 year (all p < 0.001 between groups). Adjusting for baseline LDL-C levels, hazard ratio (HR) for those reaching 2.0-2.5 mmol/l LDL-C versus those reaching <2.0 mmol/l was 1.16 (95% confidence interval [CI], 1.02-1.33, p = 0.023). An increase of the apolipoprotein B/A1 (apoB/A1) ratio by 1 standard deviation in participants who reached 2.0 mmol/l showed a HR for CVD of 1.14 (95% CI, 1.04-1.25, p = 0.004).

CONCLUSION

More CVD patients treated with atorvastatin than simvastatin achieved either LDL-C goal and those reaching the 2.0 mmol/l goal exhibited significantly less CVD than those only reaching 2.5 mmol/l. In those reaching the 2.0 mmol/l goal, the apoB/A1 ratio still bears a relation to CVD outcome. The use of apoB/A1 ratio may provide additional predictive value to that of LDL-C.

Apolipoprotein B/A-I and total cholesterol/high-density lipoprotein cholesterol ratios both predict cardiovascular events in the general population independently of nonlipid risk factors, albuminuria and C-reactive protein

BACKGROUND

the total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C) and apolipoprotein (apo) B/A-I ratios predict major adverse cardiovascular events (MACEs). The extent to which these associations are modified by high-sensitivity C-reactive protein (hs-CRP) and albuminuria is largely unknown. We compared the strength of these ratios with first MACE in the general population and determined whether these associations remain when taking account of these risk markers.

SUBJECTS AND METHODS

a prospective case-cohort study was performed among 6948 subjects (PREVEND cohort) without previous cardiovascular disease and who did not use lipid-lowering drugs initially. Fasting serum TC, low-density lipoprotein cholesterol (LDL-C), HDL-C, non-HDL-C, apoB, apoA-I, triglycerides, hs-CRP and albuminuria were measured at baseline. The composite endpoint was incident MACE.

RESULTS

a total of 362 first cardiovascular events occurred during 7.9 years of follow-up. All pro- and anti-atherogenic measures of lipoproteins and apos predicted MACEs in age- and sex-adjusted Cox proportional hazard analyses (P = 0.018 to P < 0.001). The age- and sex-adjusted hazard ratio (HR) was 1.37 [95% confidence interval (CI), 1.26-1.48] for the apoB/apoA-I ratio and 1.24 (95% CI, 1.18-1.29) for the TC/HDL-C ratio (both P < 0.001). These relationships were essentially unaltered after additional adjustment for triglyceride levels. Pair-wise comparison revealed that these ratios were of similar importance in age- and sex-adjusted analysis (P = 0.397). The HRs of apoB/apoA-I (P < 0.001) and TC/HDL-C (P < 0.001) for risk of MACEs were only marginally attenuated by additional controlling for traditional risk factors (hypertension, diabetes, obesity and smoking), hs-CRP and albuminuria.

CONCLUSIONS

first MACE is associated with both the fasting serum apoB/apoA-I ratio and the TC/HDL-C ratio in the general population, independently of triglycerides, hs-CRP and albuminuria.

Targeting residual risk: the rationale for the use of non-HDL cholesterol

There is a wealth of epidemiological and clinical data linking low-density lipoprotein cholesterol (LDLc) with atherosclerotic cardiovascular disease. Numerous primary and secondary prevention trials have demonstrated that reduction in LDLc leads to significant decrease in cardiovascular event rates. However, patients continue to be at significant risk for recurrent events despite aggressive LDLc lowering, reflecting a substantial residual risk. Numerous parameters like apolipoprotein B, LDL particle size, number and non-high density lipoprotein cholesterol (non-HDLc) measurement have been used to assess and address this high residual risk. Herein, we discuss the rationale and the evidence supporting the use of non-HDLc. We also discuss therapeutic options and provide a practical approach to residual risk reduction from a primary care perspective.

Rosuvastatin along the cardiovascular continuum: from JUPITER to AURORA

Dyslipidemia is one of the major causes of atherosclerosis, although in the last few years an increase in cholesterol control rates has been reported. However, results from the European Action on Secondary and Primary Prevention by Intervention to Reduce Events (EUROASPIRE) surveys indicate that approximately 50% of the patients with ischemic heart disease still do not attain LDL-cholesterol goals despite the use of lipid-lowering therapy (including statins). Rosuvastatin is a new and potent statin that produces greater reductions of LDL-cholesterol when compared with other agents in this class. Furthermore, rosuvastatin provides additional benefits in the lipid profile such as increased HDL-cholesterol, and decreased triglycerides, total cholesterol, apolipoprotein B and apolipoprotein B:A-1 ratio. Cardiovascular disease is a continuum: from risk factors to subclinical organ damage and finally to overt clinical cardiovascular disease. Several trials have investigated the effects of rosuvastatin along this cardiovascular continuum. The results provided by the GALAXY program emphasize the importance of the early treatment with rosuvastatin in the cardiovascular continuum to achieve the greatest benefit. In this paper, the efficacy and safety of rosuvastatin along the cardiovascular continuum is reviewed.

Simvastatin and tempol protect against endothelial dysfunction and renal injury in a model of obesity and hypertension

Obesity and hypertension are risk factors for the development of chronic kidney disease. The mechanisms by which elevated blood pressure and fatty acids lead to the development of renal injury are incompletely understood. Here, we investigated the contributions of cholesterol and oxidative stress to renal endothelial dysfunction and glomerular injury in a model of obesity and hypertension. Male Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) were fed a normal diet, a high-fat diet, a high-fat diet with tempol, or a high-fat diet with simvastatin for up to 10 wk. Blood pressure was not altered by a high-fat diet or treatments. After 3 wk, renal afferent dilatory responses to acetylcholine were impaired in WKY rats and SHR fed a high-fat diet. Tempol treatment prevented this vascular dysfunction in both strains; however, simvastatin treatment demonstrated greater beneficial effects in the SHR. Albuminuria was observed in the SHR and was exacerbated by a high-fat diet. Tempol and simvastatin treatment significantly ameliorated albuminuria in the SHR fed a high-fat diet. Ten weeks on a high-fat resulted in an increase in urinary 8-isoprostane in WKY rats and SHR, and tempol and simvastatin treatment prevented this increase, indicating a reduction in renal oxidative stress. Monocyte chemoattractant protein-1 (MCP-1) excretion was significantly elevated by a high-fat diet in both strains, and tempol prevented this increase. Interestingly, simvastatin treatment had no effect on MCP-1 levels. These data indicate that tempol and simvastatin treatment via a reduction in oxidative stress improve renal endothelial function and decrease glomerular injury in a model of obesity and hypertension.

Atorvastatin affects low density lipoprotein and non-high density lipoprotein cholesterol relations with apolipoprotein B in type 2 diabetes mellitus: modification by triglycerides and cholesteryl ester transfer protein

OBJECTIVES

Non-HDL-cholesterol (non-HDL-C) and apolipoprotein (apo) B are proposed as treatment targets. The extent to which statin therapy affects relationships of LDL-C and non-HDL-C with apoB was examined in type 2 diabetes.

METHODS

Analyses were performed in 217 hypertriglyceridaemic type 2 diabetic patients (Diabetes Atorvastatin Lipid Intervention (DALI) cohort). 61 patients randomized to placebo, 70 to 10 mg atorvastatin daily and 65 - 80 mg atorvastin daily completed follow-up.

RESULTS

Baseline fasting LDL-C of 2.42 mmol/l and non-HDL-C of 3.69 mmol/l corresponded to the apoB guideline target of 0.90 g/l. During atorvastatin (10 and 80 mg daily), the LDL-C target was achieved most frequently, and lower LDL-C (2.38 and 2.29 mmol/l) and non-HDL-C (3.24 and 3.19 mmol/l) concentrations corresponded to this apoB goal. Decreases in LDL-C during atorvastatin treatment were negatively related (p < 0.001), but decreases in non-HDL-C were positively related to changes in triglycerides (p < 0.001), independently from decreases in apoB (p < 0.001 for all). Decreases in LDL-C and non-HDL-C were positively associated with decreases in cholesteryl ester transfer protein mass (p < 0.001).

CONCLUSIONS

During atorvastatin lower LDL-C and non-HDL-C levels correspond to the apoB guideline target, which would favour its use as treatment target.

Correlation of non-high-density lipoprotein cholesterol and low-density lipoprotein cholesterol with apolipoprotein B during simvastatin + fenofibrate therapy in patients with combined hyperlipidemia (a subanalysis of the SAFARI trial)

Guidelines have recommended non-high-density lipoprotein (non-HDL) cholesterol as a secondary target for therapy after the low-density lipoprotein (LDL) cholesterol goals have been met in patients with hypertriglyceridemia; non-HDL cholesterol is viewed as a surrogate for apolipoprotein (Apo)B, an alternate end point of treatment. The present analysis of the previously reported Simvastatin plus Fenofibrate for Combined Hyperlipidemia (SAFARI) trial assessed the associations of non-HDL cholesterol and LDL cholesterol with ApoB levels in patients with combined hyperlipidemia treated with combination simvastatin (20 mg) and fenofibrate (160 mg) or simvastatin monotherapy (20 mg). The correlations of these factors were analyzed in the overall modified intent-to-treat population (n = 594) and in patient subgroups stratified by triglyceride (TG) tertiles. Simvastatin plus fenofibrate and simvastatin alone significantly reduced LDL cholesterol, TG, non-HDL cholesterol and ApoB levels and non-HDL cholesterol/ApoB ratio (p < or =0.0004), regardless of the TG level. The greatest reductions occurred with combination treatment. The baseline levels of non-HDL cholesterol and LDL cholesterol correlated highly with ApoB and were stronger in the lower TG tertiles than in the higher TG tertiles. After 12 weeks, the correlations had changed little with simvastatin monotherapy but had increased substantially with combination therapy and were most improved at high TG levels. In conclusion, these results suggest that both non-HDL cholesterol and ApoB provide similar information in relation to treatment response in patients with combined hyperlipidemia and hypertriglyceridemia, and that non-HDL cholesterol is a good indicator of ApoB-containing lipoproteins, supporting its recommended use as a secondary therapeutic target in these patients.

Targets for LDL-lowering therapy

PURPOSE OF REVIEW

To compare non-HDL-cholesterol (non-HDL-C) and apolipoprotein B (apoB) as targets for LDL-lowering therapy. The conventional approach is restricted to a comparison of in-trial data. Although essential, this overlooks the issue as to which marker better identifies residual risk after any particular treatment regimen.

RECENT FINDINGS

Data from a series of recent studies, including Justification for the Use of Statins in Primary Prevention: an Intervention Trial Evaluating Rosuvastatin, Measuring Effective Reductions in Cholesterol Using Rosuvastatin Therapy II, Treating to New Targets-Incremental Decrease in End Points Through Aggressive Lipid Lowering and Collaborative Atorvastatin Diabetes Study, demonstrating that apoB better identifies residual risk than non-HDL-C will be reviewed.

SUMMARY

Comparing markers such as non-HDL-C and apoB for the accuracy with which they identify risk during a trial is essential but not sufficient. It is also necessary to compare markers for how well they identify residual risk, and, in this regard, apoB clearly outperforms non-HDL-C.

Effects of rosuvastatin and atorvastatin on LDL and HDL particle concentrations in patients with metabolic syndrome: a randomized, double-blind, controlled study

OBJECTIVE

The purpose of this study was to examine the effects of statin therapy on lipoprotein particle concentrations in patients with the metabolic syndrome. Changes in lipoprotein particle concentration may predict the risk of coronary heart disease more accurately than lipoprotein cholesterol levels.

RESEARCH DESIGN AND METHODS

Patients with dyslipidemia and the metabolic syndrome (n = 318) were randomly assigned in a double-blind study comparing 10 mg rosuvastatin (RSV), 10 mg atorvastatin, or placebo daily for 6 weeks. From weeks 6 to 12, patients in the RSV and placebo groups received 20 mg RSV, whereas the ATV group increased their dose to 20 mg daily. Lipoprotein particle concentrations were measured by nuclear magnetic resonance spectroscopy, LDL cholesterol was measured by beta-quantification, and other lipoproteins were measured by standard methods at baseline, 6 weeks, and 12 weeks. Lipoprotein levels were compared by analysis of covariance.

RESULTS

Statins reduced LDL particle concentration less than LDL cholesterol (-30 to -38 vs. -38 to -51%). Reductions were greater with RSV than with ATV (P < 0.05 for LDL particle concentration and P < 0.001 for LDL cholesterol). Most patients attained LDL cholesterol <2.59 mmol/l (100 mg/dl) at 12 weeks (80% with RSV and 59% with ATV; P = 0.003), but only 27% of patients receiving RSV and 19% receiving ATV attained the goal of LDL particle concentration <1,000 nmol/l (P = 0.07).

CONCLUSIONS

In patients with the metabolic syndrome, statin-induced changes in LDL cholesterol do not accurately reflect changes in LDL particle concentration. Consequently, despite attainment of LDL cholesterol goals, these patients may retain considerable residual coronary heart disease risk.

Efficacy and safety of rosuvastatin in the management of dyslipidemia

Rosuvastatin is a synthetic statin that represents an advance in the pharmacologic and clinical properties of statins. Relative to other statins, rosuvastatin possesses a greater number of binding interactions with HMG-CoA reductase and has a high affinity for the active site of the enzyme. As with other statins, serious adverse effects with rosuvastatin therapy are uncommon and primarily involve effects on the liver and skeletal muscle. The risk increases with increasing dosages and coadministration with other drugs interacting with the same metabolic pathway. The degree of LDL reduction is important to achieve the treatment goals suggested by international guidelines. Among the most potent statins, rosuvastatin is capable of getting the majority of patients to their LDL cholesterol goals. In addition, rosuvastatin has been found effective in reducing small-dense LDL, C-reactive protein and in increasing HDL cholesterol levels. Controlled clinical trials using vascular end-points have been performed. In particular, a study demonstrated that rosuvastatin therapy could slow progression and/or cause regression of carotid intima-media thickness over 2 years in middle-aged individuals with a low Framingham risk score (FRS) and mild to moderate subclinical atherosclerosis. A primary prevention study (JUPITER) was stopped before the programmed end of the study, because of excess benefit for high-risk individuals receiving rosuvastatin treatment. It is suggested that pronounced LDL reduction, in association with significant HDL cholesterol increase, are the bases of a marked preventive action of rosuvastatin. The results from JUPITER support the use of rosuvastatin for primary cardiovascular prevention, in overweight men and women, with near to normal LDL cholesterol and high CRP. There is now evidence of benefit from rosuvastatin treatment for a wide segment of the general population at intermediate cardiovascular risk. In absolute numbers, this segment represents the main source of cardiovascular events: on the basis of JUPITER results, it is expected that treatment target and potential candidates to statin therapy will be revaluated and redefined.

Perspectives on low-density lipoprotein cholesterol goal achievement

BACKGROUND

Elevated levels of low-density lipoprotein cholesterol (LDL-C) are associated with an increased risk of coronary heart disease (CHD). European and US guidelines now recommend lower LDL-C levels, particularly in high-risk patients. Although LDL-C treatment goals to reduce the risk of CHD are clear, many patients do not reach their LDL-C goals.

OBJECTIVES

Examine consensus guideline targets for LDL-C lowering in patients at high or very high cardiovascular risk; examine cholesterol goal achievement in clinical practice; evaluate the effectiveness of ezetimibe/statin and other adjunctive lipid-lowering treatments in achieving LDL-C goals; and consider ongoing controversies and the randomized controlled trials that may help to resolve or better illuminate them.

METHODS

An English-language PubMed search was conducted to identify prospective randomized controlled trials, open-label studies, and retrospective and observational studies from 2001 (same year that the executive summary of the National Cholesterol Education Program's Adult Treatment Panel III was published) to present for an analysis of the effects of adjunctive therapies on LDL-C lowering and goal attainment in patients at elevated cardiovascular risk.

RESULTS

Elevated LDL-C is the primary target of lipid-lowering therapy; aggressive lowering is of great benefit to those at high risk. Statins are recommended first-line lipid-lowering agents, with a long, well-regarded history of efficacy and safety. Not all patients, however, can achieve recommended LDL-C goals simply using starting doses of statins. For such patients, more intensive therapy utilizing high-dose statins or combination therapy, including statins combined with other lipid-lowering agents, such as ezetimibe, bile acid resins (BARs), or niacin, is warranted. Potential limitations of the present review include possible publication bias and the focus on pharmacotherapy rather than lifestyle modification and the important objective of multiple risk-factor modification to reduce absolute global cardiovascular risk.

CONCLUSIONS

With a well-established link between elevated LDL-C and cardiovascular risk, aggressive LDL-C lowering becomes particularly important. Patients needing intensive LDL-C lowering to achieve goals will often require adjunctive treatments, including ezetimibe, BARs, or niacin along with statins. Given both their high mg: mg potency in lowering LDL-C and favorable tolerability and patient acceptance/adherence profile, ezetimibe/statin combination regimens arguably provide the greatest likelihood for patients to reach new, lower LDL-C targets; however, efficacy and safety data of any adjunctive treatment, along with drug costs and patient adherence to treatment (partly related to complexity of the regimen) all need to be considered when determining the optimal regimen to achieve LDL-C goals in individual patients according to their baseline absolute cardiovascular risk, LDL-C level, and consensus LDL-C targets.

Ezetimibe/simvastatin compared with atorvastatin or rosuvastatin in lowering to specified levels both LDL-C and each of five other emerging risk factors for coronary heart disease: Non-HDL-cholesterol, TC/HDL-C, apolipoprotein B, apo-B/apo-A-I, or C-reactive protein

BACKGROUND

Recent evidence suggests that in addition to low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (Apo-B), non-high-density lipoprotein cholesterol (non-HDL-C), some lipoprotein ratios, and C-reactive protein (CRP) are predictive of coronary heart disease (CHD) risk. This post-hoc analysis of two trials comparing single-tablet ezetimibe/simvastatin (EZE/SIMVA) to atorvastatin (ATORVA) or rosuvastatin (ROSUVA) evaluates the proportion of patients attaining LDL-C <70 mg/dL and specific levels of these emerging risk factors.

METHODS

These were double-blind, 6-week, parallel group trials of hypercholesterolemic patients randomized to milligram equivalent doses of ATORVA versus EZE 10 mg/SIMVA, or to usual starting, next higher, and maximum doses of ROSUVA versus EZE/SIMVA. This analysis examined the percent of patients in prespecified dose comparisons and overall achievement of LDL-C <70 mg/dL and/or Apo-B <90 mg/dL, total cholesterol (TC)/HDL-C <4.0, or Apo-B/Apo-A-I <0.7 among all treated patients, non-HDL-C <100 mg/dL among patients with baseline triglycerides ≥200 mg/dL, or CRP <2.0 mg/L among patients with baseline CRP ≥2.0 mg/L.

RESULTS

Within each trial, baseline characteristics were similar among groups. At all dose comparisons, significantly more patients receiving EZE/SIMVA reached LDL-C <70 mg/dL and achieved both LDL-C <70 mg/dL and either Apo-B <90 mg/dL, TC/HDL-C <4.0, or Apo-B/Apo-A-I <0.7 (EZE/SIMVA versus ATORVA) compared to ATORVA and ROSUVA. For most dose comparisons, significantly more patients receiving EZE/SIMVA attained both LDL-C <70 mg/dL and either non-HDL-C <100 mg/dL or CRP <2 mg/L compared to ATORVA or ROSUVA.

CONCLUSION

The greater efficacy related to changes in blood lipids of EZE/SIMVA compared with both ATORVA and ROSUVA extends to changes in many emerging risk factors. Ultimate clinical implications of these findings still need to be defined.