High-dose atorvastatin therapy in severe heterozygous familial hypercholesterolaemia

Lipoprotein metabolism in familial hypercholesterolemia

Familial hypercholesterolemia (FH) is one of the most common genetic disorders in humans. It is an extremely atherogenic metabolic disorder characterized by lifelong elevations of circulating LDL-C levels often leading to premature cardiovascular events. In this review, we discuss the clinical phenotypes of heterozygous and homozygous FH, the genetic variants in four genes (LDLR/APOB/PCSK9/LDLRAP1) underpinning the FH phenotype as well as the most recent in vitro experimental approaches used to investigate molecular defects affecting the LDL receptor pathway. In addition, we review perturbations in the metabolism of lipoproteins other than LDL in FH, with a major focus on lipoprotein (a). Finally, we discuss the mode of action and efficacy of many of the currently approved hypocholesterolemic agents used to treat patients with FH, with a special emphasis on the treatment of phenotypically more severe forms of FH.

Lipid-lowering efficacy of atorvastatin

BACKGROUND

This represents the first update of this review, which was published in 2012. Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

Primary objective To quantify the effects of various doses of atorvastatin on serum total cholesterol, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol and triglycerides in individuals with and without evidence of cardiovascular disease. The primary focus of this review was determination of the mean per cent change from baseline of LDL-cholesterol. Secondary objectives • To quantify the variability of effects of various doses of atorvastatin.• To quantify withdrawals due to adverse effects (WDAEs) in placebo-controlled randomised controlled trials (RCTs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 11, 2013), MEDLINE (1966 to December Week 2 2013), EMBASE (1980 to December Week 2 2013), Web of Science (1899 to December Week 2 2013) and BIOSIS Previews (1969 to December Week 2 2013). We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of three to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included and extracted data. We collected information on withdrawals due to adverse effects from placebo-controlled trials.

MAIN RESULTS

In this update, we found an additional 42 trials and added them to the original 254 studies. The update consists of 296 trials that evaluated dose-related efficacy of atorvastatin in 38,817 participants. Included are 242 before-and-after trials and 54 placebo-controlled RCTs. Log dose-response data from both trial designs revealed linear dose-related effects on blood total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides. The Summary of findings table 1 documents the effect of atorvastatin on LDL-cholesterol over the dose range of 10 to 80 mg/d, which is the range for which this systematic review acquired the greatest quantity of data. Over this range, blood LDL-cholesterol is decreased by 37.1% to 51.7% (Summary of findings table 1). The slope of dose-related effects on cholesterol and LDL-cholesterol was similar for atorvastatin and rosuvastatin, but rosuvastatin is about three-fold more potent. Subgroup analyses suggested that the atorvastatin effect was greater in females than in males and was greater in non-familial than in familial hypercholesterolaemia. Risk of bias for the outcome of withdrawals due to adverse effects (WDAEs) was high, but the mostly unclear risk of bias was judged unlikely to affect lipid measurements. Withdrawals due to adverse effects were not statistically significantly different between atorvastatin and placebo groups in these short-term trials (risk ratio 0.98, 95% confidence interval 0.68 to 1.40).

AUTHORS' CONCLUSIONS

This update resulted in no change to the main conclusions of the review but significantly increases the strength of the evidence. Studies show that atorvastatin decreases blood total cholesterol and LDL-cholesterol in a linear dose-related manner over the commonly prescribed dose range. New findings include that atorvastatin is more than three-fold less potent than rosuvastatin, and that the cholesterol-lowering effects of atorvastatin are greater in females than in males and greater in non-familial than in familial hypercholesterolaemia. This review update does not provide a good estimate of the incidence of harms associated with atorvastatin because included trials were of short duration and adverse effects were not reported in 37% of placebo-controlled trials.

Lipid lowering efficacy of atorvastatin

BACKGROUND

Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

To quantify the dose-related effects of atorvastatin on blood lipids and withdrawals due to adverse effects (WDAE).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library Issue 4, 2011, MEDLINE (1966 to November 2011), EMBASE (1980 to November 2011), ISI Web of Science (1899 to November 2011) and BIOSIS Previews (1969 to November 2011). No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of 3 to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. WDAE information was collected from the placebo-controlled trials.

MAIN RESULTS

Two hundred fifty-four trials evaluated the dose-related efficacy of atorvastatin in 33,505 participants. Log dose-response data revealed linear dose-related effects on blood total cholesterol, low-density lipoprotein (LDL)-cholesterol and triglycerides. Combining all the trials using the generic inverse variance fixed-effect model for doses of 10 to 80 mg/day resulted in decreases of 36% to 53% for LDL-cholesterol. There was no significant dose-related effects of atorvastatin on blood high-density lipoprotein (HDL)-cholesterol. WDAE were not statistically different between atorvastatin and placebo for these short-term trials (risk ratio 0.99; 95% confidence interval 0.68 to 1.45).

AUTHORS' CONCLUSIONS

Blood total cholesterol, LDL-cholesterol and triglyceride lowering effect of atorvastatin was dependent on dose. Log dose-response data was linear over the commonly prescribed dose range. Manufacturer-recommended atorvastatin doses of 10 to 80 mg/day resulted in 36% to 53% decreases of LDL-cholesterol. The review did not provide a good estimate of the incidence of harms associated with atorvastatin because of the short duration of the trials and the lack of reporting of adverse effects in 37% of the placebo-controlled trials.

Effects of statin on small dense low-density lipoprotein cholesterol and remnant-like particle cholesterol in heterozygous familial hypercholesterolemia

AIM

The effects of statin on small dense low-density lipoprotein cholesterol (sd-LDL-C) and remnant-like particle cholesterol (RLP-C) levels in heterozygous familial hypercholesterolemia (FH) have not been examined. This study aimed to clarify the effects of statin on sd-LDL-C and RLP-C levels in heterozygous FH.

METHODS

Seventeen patients with heterozygous FH were randomly assigned to 2 mg/day pitavastatin or 10 mg/day atorvastatin. At baseline and 12 weeks after treatment with statin, we measured sd-LDL-C and RLP-C levels.

RESULTS

Sd-LDL-C levels significantly decreased from 43 +/- 24 to 16 +/- 10 mg/dL (-63%, p=0.001) in the pitavastatin group, and from 44 +/- 17 to 19 +/- 10 mg/dL (-55%, p<0.001) in the atorvastatin group. RLP-C levels decreased from 8.4 +/- 2.8 to 6.6 +/- 2.7 mg/dL (-16%, p=0.156) in the pitava-statin group, and from 9.8 +/- 4.7 to 5.9 +/- 5.4 mg/dL (-45%, p=0.044) in the atorvastatin group. There were no significant differences in percent changes of sd-LDL-C (p=0.370) and RLP-C levels (p=0.097) between the two groups.

CONCLUSIONS

Sd-LDL-C measured by the heparin-magnesium precipitation method and RLP-C levels in heterozygous FH were decreased by 12 weeks of statin therapy. Statin might have additional anti-atherogenic effects by reducing not only LDL-C but also sd-LDL-C and RLP-C.

Cross-Over Trial of Intensive Monotherapy With Atorvastatin and Combined Therapy With Atorvastatin and Colestimide for Japanese Familial Hypercholesterolemia

BACKGROUND

In familial hypercholesterolemia (FH), low-density lipoprotein-cholesterol (LDL-C)-lowering therapy is important to avoid predisposition to coronary artery disease. This study investigated the advantages of combined therapy with atorvastatin and colestimide vs intensive monotherapy with atorvastatin.

METHODS AND RESULTS

The trial used a randomized cross-over design consisting of 2 16-week periods of open-label drug therapy. Among the 24 initial patients, 17 heterozygous FH patients (age: 54.1 years; 5 males) were enrolled after 20 mg/day atorvastatin failed to achieve their target level. The patients received 20 mg/day atorvastatin and 3 g/day colestimide or 40 mg/day atorvastatin. Fifteen patients completed the trial and their LDL-C reduced from 5.07 +/- 1.10 mmol/L to 3.76 +/- 0.90 mmol/L with the combined therapy and to 3.81 +/- 0.50 mmol/L with the intensive monotherapy. Although the 2 therapies showed comparable mean effects for decreasing LDL-C, similar adverse reaction and cost, each therapy was predominantly more effective in some patients than in others. The triglyceride and high-density lipoprotein cholesterol levels were similar in both therapies.

CONCLUSIONS

To achieve the therapeutic target of LDL-C level for refractory FH, the LDL-C-lowering therapy selected can be either intensive monotherapy or combined therapy as the next to standard statin therapy.

Efficacy of ezetimibe in patients with statin-resistant and statin-intolerant familial hyperlipidaemias

OBJECTIVE

To investigate the efficacy of the cholesterol absorption inhibitor ezetimibe in patients with refractory familial hyperlipidaemia or intolerant to statin therapy.

METHODS

This prospective study assessed the safety and efficacy of ezetimibe in 200 patients with refractory familial hyperlipidaemias not achieving a low-density-lipoprotein (LDL) cholesterol < 3 cholesterol < 3 mmol/L (116 mg/dL) including 22% intolerant to all statin therapy, many consuming intolerant to all statin therapy, many consuming sterol-containing products.

RESULTS

Ezetimibe monotherapy resulted in 7% and 11% reductions in LDL-cholesterol and apolipoprotein B respectively. Ezetimibe-statin combination therapy reduced LDL-cholesterol by an additional 11 +/- 27% and apolipoprotein B by 11 (+79 to -18)%. There was a similar response between various sub-groups but a wide variation within groups with the greatest effect seen in patients groups with the greatest effect seen in patients under-responding to statins. The number of patients achieving the LDL-C target of 3 mmol/L rose from 5.5% to 18%. Non-significant effects included a 5 (+78 to -470)% reduction in triglycerides, 8 +/- 36% increment in HDL-cholesterol, 21 (+35 to -82)% reduction in C-reactive protein and a 1 (+20 to -50)% increase in alanine transaminase. No effects were seen on creatinine, creatine kinase, or insulin resistance. Fourteen patients (7%) discontinued ezetimibe: seven due to gastrointestinal side-effects, one patient developed an ezetimibe-induced hypercholesterolaemia (x 1.5), one developed ezetimibe-induced hypertriglyceridaemia (x 7) and five discontinued for other reasons.

CONCLUSION

Ezetimibe is a useful addition to statins in patients with familial hyperlipidaemias but shows a highly variable response profile.

Efficacy and safety of rosuvastatin alone and in combination with cholestyramine in patients with severe hypercholesterolemia: A randomized, open-label, multicenter trial

BACKGROUND

Patients with severe hypercholesterolemia may need greater cholesterol reductions than can be achieved with statin therapy alone.

OBJECTIVE

The primary objective of this trial was to compare the efficacy of a combination of rosuvastatin plus cholestyramine with that of rosuvastatin alone for reducing low-density lipoprotein cholesterol (LDL-C) levels after 6 weeks of treatment.

METHODS

In this open-label, multicenter, randomized, parallel-group, comparator trial, adult patients with severe hypercholesterolemia (LDL-C level, 190-400 mg/dL) received rosuvastatin 40 mg/d for 6 weeks after a 6-week dietary lead-in period and were then randomized to 6 weeks of treatment with rosuvastatin 80 mg/d alone or rosuvastatin 80 mg/d plus cholestyramine 16 g/d (8 g BID with meals).

RESULTS

Of 153 eligible patients, 147 (83 men, 64 women; mean [SD] age, 54.5 [13.7] years; mean [SD] bodyweight, 81.3 [14.4] kg) received randomized treatment, and 144 had post baseline measurements and were included in the analysis. The mean (SD) reduction in LDL-C was 522% (13.0%) after treatment with rosuvastatin 40 mg, and the least squares mean (SE) reductions in LDL-C were 56.4% (1.8%) and 60.5% (1.8%) after treatment with rosuvastatin 80 mg alone (n = 69) and rosuvastatin 80 mg plus cholestyramine (n = 75), respectively. No significant differences between treatments were found for these or other lipid measurements. Incremental LDL-C reductions >30% were obtained in 29% (22/75) of patients receiving combination therapy and 4% (3/69) of patients receiving rosuvastatin alone. The combination therapy was less well tolerated, primarily due to gastrointestinal symptoms; otherwise, the treatments were generally well tolerated.

CONCLUSION

In this group of patients with severe hypercholesterolemia, the combination of rosuvastatin 80 mg with cholestyramine 16 g/d did not provide a significantly greater efficacy benefit than rosuvastatin alone.

Benefits and risks of simvastatin in patients with familial hypercholesterolaemia

Familial hypercholesterolaemia is a frequent, inherited, monogenic disorder, associated with accelerated development of atherosclerotic disease leading to coronary artery disease. Life expectancy of patients with familial hypercholesterolaemia is reduced by 15-30 years unless they are adequately treated with lipid-lowering therapy. Given the chronic nature of this disease, the selection of a therapeutic approach should be strongly based on its long-term safety and tolerability. The introduction of HMG-CoA reductase inhibitors has revolutionised the treatment of familial hypercholesterolaemia. Simvastatin 40-80 mg/day effectively reduces serum low density lipoprotein (LDL)-cholesterol levels. Furthermore, simvastatin reduces triglycerides and mildly raises high density lipoprotein-cholesterol levels. In addition to the hypolipidaemic effect, other potentially important effects, such as improvement of endothelial function and reduction of LDL oxidation and vascular inflammation, have been associated with HMG-CoA reductase inhibitor therapy. Simvastatin has also been shown to abolish the progression, and even facilitate the regression, of existing human atherosclerotic lesions. The good safety and tolerability profile of simvastatin is clearly highlighted by the low rate of therapy discontinuation observed in several population-based clinical trials. The most common adverse events leading to the discontinuation of therapy are gastrointestinal upset and headache. Asymptomatic elevations in liver transaminase levels and myopathy are uncommon. The overwhelming clinical evidence regarding the long-term use of HMG-CoA reductase inhibitor therapy in patients with familial hypercholesterolaemia together with the long-term safety data (particularly relating to simvastatin) provide support for the use of this drug as a first-line agent when pharmacological treatment is indicated. Early intervention with simvastatin treatment can be successfully implemented with favourable economic benefits.

Pitavastatin, a Potent Hydroxymethylglutaryl Coenzyme a Reductase Inhibitor, Increases Cholesterol 7 .ALPHA.-Hydroxylase Gene Expression in HepG2 Cells

BACKGROUND

The effect of pitavastatin on the mRNA levels of apolipoprotein (apo) A-I, peroxisome proliferator-activated receptor alpha (PPARalpha), cholesterol 7alpha-hydroxylase (CYP7A1), and farnesoid X receptor (FXR) in HepG2 cells was examined to establish whether pitavastatin affects bile acid synthesis and if so, to determine a possible molecular mechanism.

METHODS AND RESULTS

HepG2 cells were cultured in serum-free Dulbecco's modified Eagle medium for 18 h before drug treatment. Total RNA was extracted at set times and mRNA levels were quantified by reverse transcription-real time polymerase chain reaction. Pitavastatin at 0.1, 1, 5, and 10 micromol/L increased the mRNA levels of apo A-I, PPARalpha, CYP7A1, and FXR in a dose-dependent manner. The mRNA levels of apo A-I, PPAR alpha, CYP7A1, and FXR similarly increased with increasing doses of pitavastatin. Coincubation of mevalonate (4 mmol/L) with pitavastatin (5 micromol/L) reversed the inductive effects of pitavastatin on the mRNA levels of these genes, indicating that the inductive effects of pitavastatin were related to its inhibition of HMG-CoA reductase.

CONCLUSIONS

Pitavastatin increased the mRNA levels of CYP7A1 in HepG2 cells, suggesting that increased conversion of cholesterol to bile acids may be the mechanism for its potent low-density lipoprotein cholesterol-lowering effects.

Magnitude of HDL Cholesterol Variation After High-Dose Atorvastatin Is Genetically Determined at the LDL Receptor Locus in Patients With Homozygous Familial Hypercholesterolemia

Objective— The combination of LDL apheresis with high doses of a potent hepatic hydroxymethylglutaryl coenzyme A reductase inhibitor, such as atorvastatin, has been the best therapy available for the prevention of cardiovascular disease in patients with homozygous familial hypercholesterolemia (HFH). However, some concerns have been made about the effect of atorvastatin on HDL cholesterol levels in these patients.

Methods and Results— HDL cholesterol levels were determined bimonthly over the course of 2 years of treatment with high-dose atorvastatin in genotypically defined HFH patients either receptor-defective (n=6) or receptor-negative (n=6) under long-term treatment with LDL apheresis. We additionally stratified the atorvastatin effect on HDL cholesterol according to the genotype as an indicator of residual in vivo LDL receptor activity. Our findings indicate that (1) an early and transitory reduction of plasma HDL cholesterol levels occurs during the first 4 weeks of atorvastatin treatment; (2) the degree of the transient HDL reduction is higher in receptor-negative than in receptor-defective patients (−21±11 versus −10±4%; P =0.01); and (3) after long-term treatment, HDL cholesterol concentration remains higher in receptor-defective than receptor-negative patients ( P =0.026).

Conclusions— The present study reveals that HDL cholesterol reduction after high-dose atorvastatin is an early and transient event in HFH patients which magnitude depends on the presence of a residual LDL-R activity.

Long-term treatment with pitavastatin (NK-104), a new HMG-CoA reductase inhibitor, of patients with heterozygous familial hypercholesterolemia

The clinical efficacy and safety of pitavastatin (NK-104), a novel HMG-CoA reductase inhibitor, during long-term treatment, were examined in 25 patients (male/female=11/14, mean age=53+/-13 (mean+/-SD) years) with heterozygous familial hypercholesterolemia (FH). After a period on placebo of >4 weeks, 2 mg/day of pitavastatin was administered for 8 weeks, and the dose was increased to 4 mg/day for up to 104 weeks. Total cholesterol (TC) decreased by 31% from the initial value of 340+/-57 to 237+/-40 mg/dl (P<0.0001) at week 8. During treatment with the higher dose, TC decreased even further to 212+/-35 mg/dl at week 12; it decreased by 37% from the initial value (P<0.0001). Similarly, the baseline low-density lipoprotein (LDL)-cholesterol (LDL-C) decreased by 41% at week 8, and by 49% at week 12, from 267+/-61 mg/dl at baseline. These findings indicate a dose-dependent effect of the drug on TC and LDL-C concentrations. To examine whether the levels of circulating matrix metalloproteinases (MMPs) and their endogenous inhibitors (tissue inhibitors of metalloproteinases: TIMPs) are altered during lipid-lowering therapy, we also measured their plasma levels. The mean levels of MMP-2 and -3 were significantly increased. No significant alteration was found in MMP-9, TIMP-1 and -2 levels. As for the safety of pitavastatin, adverse reactions were observed in one case (4%) of subjective and objective symptoms. The effects of pitavastatin on TC and LDL-C were stable during long treatment of patients with heterozygous FH.

Atorvastatin: an updated review of its pharmacological properties and use in dyslipidaemia

Atorvastatin is a synthetic hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. In dosages of 10 to 80 mg/day, atorvastatin reduces levels of total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride and very low-density lipoprotein (VLDL)-cholesterol and increases high-density lipoprotein (HDL)-cholesterol in patients with a wide variety of dyslipidaemias. In large long-term trials in patients with primary hypercholesterolaemia. atorvastatin produced greater reductions in total cholesterol. LDL-cholesterol and triglyceride levels than other HMG-CoA reductase inhibitors. In patients with coronary heart disease (CHD), atorvastatin was more efficacious than lovastatin, pravastatin. fluvastatin and simvastatin in achieving target LDL-cholesterol levels and, in high doses, produced very low LDL-cholesterol levels. Aggressive reduction of serum LDL-cholesterol to 1.9 mmol/L with atorvastatin 80 mg/day for 16 weeks in patients with acute coronary syndromes significantly reduced the incidence of the combined primary end-point events and the secondary end-point of recurrent ischaemic events requiring rehospitalisation in the large. well-designed MIRACL trial. In the AVERT trial, aggressive lipid-lowering therapy with atorvastatin 80 mg/ day for 18 months was at least as effective as coronary angioplasty and usual care in reducing the incidence of ischaemic events in low-risk patients with stable CHD. Long-term studies are currently investigating the effects of atorvastatin on serious cardiac events and mortality in patients with CHD. Pharmacoeconomic studies have shown lipid-lowering with atorvastatin to be cost effective in patients with CHD, men with at least one risk factor for CHD and women with multiple risk factors for CHD. In available studies atorvastatin was more cost effective than most other HMG-CoA reductase inhibitors in achieving target LDL-cholesterol levels. Atorvastatin is well tolerated and adverse events are usually mild and transient. The tolerability profile of atorvastatin is similar to that of other available HMG-CoA reductase inhibitors and to placebo. Elevations of liver transaminases and creatine phosphokinase are infrequent. There have been rare case reports of rhabdomyolysis occurring with concomitant use of atorvastatin and other drugs.

CONCLUSION

Atorvastatin is an appropriate first-line lipid-lowering therapy in numerous groups of patients at low to high risk of CHD. Additionally it has a definite role in treating patients requiring greater decreases in LDL-cholesterol levels. Long-term studies are under way to determine whether achieving very low LDL-cholesterol levels with atorvastatin is likely to show additional benefits on morbidity and mortality in patients with CHD.

Effects of NK-104, a new hydroxymethylglutaryl-coenzyme reductase inhibitor, on low-density lipoprotein cholesterol in heterozygous familial hypercholesterolemia. Hokuriku NK-104 Study Group

The clinical efficacy of NK-104, a novel and totally synthetic hydroxymethylglutaryl-coenzyme A reductase inhibitor, was assessed in 30 patients (men/women = 15/15, mean age 51 years) with heterozygous familial hypercholesterolemia. After a placebo phase of >4 weeks, NK-104 was given at an initial dose of 2 mg/day for 8 weeks, which was increased to 4 mg/day for a further 8 weeks. As a result of 2 mg/day of NK-104 treatment, mean +/- SD of total and low-density lipoprotein cholesterol levels decreased significantly (p<0.0001) from baseline, namely from 8.80+/-1.38 to 6.11+/-1.09 mmol/L (-31%) and from 6.81+/-1.52 to 4.09+/-1.03 mmol/L (-40%), respectively. They decreased further (p<0.0001) as a result of 4-mg/day administration, to 5.52+/-0.81 mmol/L (-37%) and 3.55+/-0.85 mmol/L (-48%), respectively. Changes in high-density lipoprotein cholesterol levels failed to reach statistical significance. Serum triglyceride levels decreased significantly (p<0.0001) from baseline as a result of 4 mg/day of NK-104, from 1.99+/-1.72 to 1.35+/-0.90 mmol/L (-23%). Serum apolipoprotein B, CII, CIII, and E levels significantly decreased: mean changes from baseline at the end of the study were -41% (p<0.0001), -27% (p<0.0001), -19% (p = 0.002), and -37% (p<0.0001), respectively. On the other hand, apolipoprotein AI and All levels significantly increased as a result of the treatment: + 10% (p = 0.002) and +6% (p = 0.008), respectively. There were no adverse events observed in either clinical or laboratory findings that could be attributed to the treatment. These results suggest that the potency of NK-104 appears to be dose-dependent, and that NK-104 is safe and well tolerated in the treatment of patients with heterozygous familial hypercholesterolemia, and thus also provides a new therapeutic choice for subjects requiring lipid-modifying therapy.