Statin tolerability: In defence of placebo-controlled trials

Administration of Evolocumab in Patients with STEMI After Emergency PCI: A Real-World Cohort Study

BACKGROUND AND OBJECTIVE

Evolocumab can reduce low-density lipoprotein cholesterol (LDL-C) levels and improve cardiovascular (CV) outcomes. While its benefits are well established in broader populations, its potential impact on patients with ST-segment elevation myocardial infarction (STEMI) undergoing emergency percutaneous coronary intervention (PCI) remains underexplored, particularly in real-world settings. This study aimed to evaluate its efficacy and safety in this specific patient group on the basis of real-world clinical experience.

METHODS

A total of 384 patients with STEMI who underwent emergency PCI at Hebei General Hospital between 1 July 2021 and 23 September 2022 were enrolled in this retrospective, single-center study. Of these, 85 patients received evolocumab (140 mg every 2 weeks) plus standard of care (SOC), while 299 received SOC alone. Patients were monitored for CV events and lipid levels during follow-up. Propensity score matching (PSM) and inverse probability treatment weighting (IPTW) were used to balance covariates.

RESULTS

The experimental group had a lower cumulative incidence of the primary composite endpoint over 18 months in the unadjusted analysis (hazard ratio [HR] = 0.353; 95% confidence interval [CI] 0.180-0.693; P = 0.002), as well as after adjustment for PSM (HR = 0.341; 95% CI 0.165-0.706; P = 0.004) and IPTW (HR = 0.461; 95% CI 0.241-0.881; P = 0.019). The 18-month cumulative incidence was 10 (12%) for evolocumab + SOC and 95 (32%) for SOC. LDL-C levels in the evolocumab + SOC group showed significant reductions across different cohorts, compared with the SOC group. No significant differences in adverse events were observed between the two groups.

CONCLUSIONS

Evolocumab plus SOC significantly reduced postoperative CV events and LDL-C levels in patients with STEMI after emergency PCI.

Impact of obesity on tolerance and persistence of statins in patients within 3months following an acute myocardial infarction: A real-world study

BACKGROUND

Recommended treatment after acute coronary syndrome (ACS) involves high-intensity statin therapy to achieve the low-density lipoprotein (LDL-C) target of<1.4mmol/L (European guidelines), but many patients discontinue statins because of real or perceived side-effects. Whether body mass index (BMI) influences statin intolerance remains unclear.

AIM

To assess statin tolerance 3months after initiation, and to identify factors determining tolerance and persistence.

METHODS

STATIC was a single-centre cohort study (November 2021 to April 2023) of patients admitted to cardiac intensive care units for ACS. The study had three stages: T0 (admission); W6 (6 weeks after ACS: statin efficiency); and M3 (3months after ACS: statin tolerance and persistence). SAMS score was used to evaluate imputability in patients reporting muscular side-effects. Multivariable analysis identified factors influencing tolerance; statin persistence was assessed using pharmacy dispensing data.

RESULTS

Overall, 289 patients were included (77.9% men; mean age 64.2years; 22.7% with BMI≥30kg/m2). At T0, 38.1% had hypertension, 28.5% dyslipidaemia and 15.9% diabetes. At discharge, 269 patients received statins: 97.0% had a high-intensity statin; 43.5% had a statin/ezetimibe combination. At W6, mean LDL-C was 1.58mmol/L, with 45.5% at the LDL-C target. At M3, 6.0% reported side-effects (3.6% muscular, 1.2% liver, 1.2% gastrointestinal). Mean SAMS score was 5.67. No significant differences in muscular or hepatic side-effects were found between patients with BMI≥30 versus<30 kg/m2. Persistence was 98.4% at M3 follow-up. The proportion of patients on a high-intensity statin or a statin/ezetimibe did not change from discharge to M3 (P=0.45 and P=1.00, respectively).

CONCLUSIONS

Statins are effective, but not always enough to reach LDL-C target. Tolerance and persistence were good, with muscular side-effects as expected, but without any guarantee of statin imputability. BMI did not influence statin tolerance in this study.

Low-density lipoprotein-cholesterol lowering effect of a nutraceutical regimen with or without ezetimibe in hypercholesterolaemic patients with statin intolerance

Background

Statins are the most widely prescribed medication to lower low-density lipoprotein cholesterol (LDL-c). However, a significant portion of patients are unable to tolerate them due to side effects, most commonly muscle related. Nutraceuticals, natural plant derivatives with lipid-lowering properties, may provide an alternative to lower LDL-c in these patients.

Aims

To investigate whether a nutraceutical regimen, either alone or in combination with ezetimibe, can lower LDL-c in patients with hypercholesterolemia who are intolerant to statins.

Methods

Participants were recruited into a double-blind, randomized, placebo-controlled intervention study. Treatments were (i) placebo, (ii) nutraceutical (500 mg berberine, 200 mg red yeast rice (RYR), 2 g plant sterols)/daily, (iii) ezetimibe (10 mg)/daily, or (iv) the combination of nutraceutical and ezetimibe/daily. At baseline and week 8, all participants provide a fasting blood sample for assessment of lipid profile and safety bloods.

Results

Fifty participants were randomized, with 44 completing the treatment period. Following adjustment for baseline levels and compared with placebo, LDL-c was significantly reduced (all p < 0.0001) with ezetimibe (-1.02 mmol/L), nutraceutical (-1.15 mmol/L) and the nutraceutical and ezetimibe combination (-1.92 mmol/L). Non-HDL cholesterol was significantly reduced (all p < 0.0001) with ezetimibe (-1.29 mmol/L), nutraceutical (-1.37 mmol/L) and the nutraceutical and ezetimibe combination (-2.18 mmol/L). Remnant cholesterol and triglycerides was significantly reduced with the nutraceutical and ezetimibe combination (p = 0.018).

Conclusion

A nutraceutical regimen (berberine, RYR and plant sterols) and ezetimibe independently and additively lower LDL-c in patients with hypercholesterolemia who are intolerant to statins.

Safety of Statins and Nonstatins for Treatment of Dyslipidemia

This article reviews the safety of statins and non-statin medications for management of dyslipidemia. Statins have uncommon serious adverse effects: myopathy/ rhabdomyolysis, which resolve with statin discontinuation, and diabetes, usually in people with risk factors for diabetes. The CVD benefit of statins far exceeds the risk of diabetes. Statin myalgia, without CK elevation, is likely caused by muscle symptoms with another etiology, or the nocebo effect. Notable adverse effects of non-statin medicines include injection site reactions (alirocumab, evolocumab, inclisiran), increased uric acid and gout (bempedoic acid), atrial fibrillation/flutter (omega-3-fatty acids), and myopathy in combination with a statin (gemfibrozil).

Statin-associated muscle symptoms-A review: Individualizing the approach to optimize care

The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, also known as "statins" are considered first-line pharmacologic therapy for reducing low-density lipoprotein cholesterol (LDL-C). They have been demonstrated efficacy in a variety of patients populations to reduce atherosclerotic cardiovascular disease (ASCVD) risk. Like any pharmacologic therapy, however, they are not without possible adverse effects that can lead to discontinuation, thus leading to a loss of benefit. The most common side effect related to statin therapy impacting compliance is musculoskeletal related, commonly referred to as statin-associated muscle systems (SAMS). While the overall incidence is relatively low, the consequences of nonadherence to statin therapy can have a negative impact on patient care. Therefore, it is important for healthcare providers to understand risk factors, how to diagnose, and how to manage this unfortunate adverse effect in order to optimize care.

Patient-Reported Outcomes from a Randomized, Active-Controlled, Open-Label, Phase 3 Trial of Burosumab Versus Conventional Therapy in Children with X-Linked Hypophosphatemia

Changing to burosumab, a monoclonal antibody targeting fibroblast growth factor 23, significantly improved phosphorus homeostasis, rickets, lower-extremity deformities, mobility, and growth versus continuing oral phosphate and active vitamin D (conventional therapy) in a randomized, open-label, phase 3 trial involving children aged 1-12 years with X-linked hypophosphatemia. Patients were randomized (1:1) to subcutaneous burosumab or to continue conventional therapy. We present patient-reported outcomes (PROs) from this trial for children aged ≥ 5 years at screening (n = 35), using a Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaire and SF-10 Health Survey for Children. PROMIS pain interference, physical function mobility, and fatigue scores improved from baseline with burosumab at weeks 40 and 64, but changed little with continued conventional therapy. Pain interference scores differed significantly between groups at week 40 (- 5.02, 95% CI - 9.29 to - 0.75; p = 0.0212) but not at week 64. Between-group differences were not significant at either week for physical function mobility or fatigue. Reductions in PROMIS pain interference and fatigue scores from baseline were clinically meaningful with burosumab at weeks 40 and 64 but not with conventional therapy. SF-10 physical health scores (PHS-10) improved significantly with burosumab at week 40 (least-squares mean [standard error] + 5.98 [1.79]; p = 0.0008) and week 64 (+ 5.93 [1.88]; p = 0.0016) but not with conventional therapy (between-treatment differences were nonsignificant). In conclusion, changing to burosumab improved PRO measures, with statistically significant differences in PROMIS pain interference at week 40 versus continuing with conventional therapy and in PHS-10 at weeks 40 and 64 versus baseline.Trial registration: ClinicalTrials.gov NCT02915705.

Adherence to lipid-lowering guidelines for secondary prevention and potential reduction in CVD events in Swedish primary care: a cross-sectional study

OBJECTIVES

The protective effect of lipid-lowering treatment for secondary prevention after coronary heart disease (CHD) has been well documented. Current guidelines recommend a target level for low-density lipoprotein cholesterol (LDL-C) of ≤1.8 mmol/L. The aim was to describe lipid-lowering treatment patterns and to provide an estimate of the potential reductions in cardiovascular disease (CVD) events with improved adherence to guidelines.

DESIGN

Cross-sectional.

SETTING

Primary care in a large Swedish region.

PARTICIPANTS

37 120 patients with CHD in a Swedish regional primary care quality register (QregPV), by 31 December 2015.

PRIMARY AND SECONDARY OUTCOME MEASURES

Proportion of patients on statin treatment and proportion of patients achieving LDL-C ≤1.8 mmol/L. Estimated number of CVD events calculated for (1) current treatment, (2) improved treatment and (3) lowered LDL-C, based on applying rate reductions from meta-analyses of randomised trials to the potentially undertreated population. Risk estimation modelling was based on 52 042 patients in the same register on January 2011 followed for 5 years.

RESULTS

Of 37 120 patients, 18% reached LDL-C ≤1.8 mmol/L and 32% were not on statin treatment. Based on individual risks, the estimated number of CVD events in the study group over 5 years was 9209/37 120. If all patients without a statin or with less potent statin treatment were given atorvastatin 80 mg, an estimated reduction of CVD events by 14% (7901 vs 9209) was seen. If all patients achieved LDL-C ≤1.8 mmol/L, the number of events was estimated to be reduced by 18% (7577 vs 9209).

CONCLUSION

One-third of patients with CHD in primary care were not on lipid-lowering treatment. Based on the assumption that included patients would react to statin therapy the same way as the patients in randomised trials, improved adherence to treatment guidelines could lead to a substantial reduction in new CVD events.

Atorvastatin-linked rhabdomyolysis caused by the simultaneous intake of amoxicillin clavulanic acid

Objectives Rhabdomyolysis is a rare syndrome in which a serious muscle damage suddenly appears, with the possible occurrence of severe complications such as kidney failure, electrolyte imbalances and death, and represents the most severe form of statin-induced muscle injury. Case presentation Here we present the case of a 55-year-old woman who started therapy with amoxicillin clavulanic acid on a background of atorvastatin therapy, resulting in rhabdomyolysis. Conclusions This case highlights the importance of evaluating potential drug interactions in patients taking statin and the need of monitoring clinical and laboratory findings suggestive of rhabdomyolysis.

Statins and muscle pain

Introduction: Statins remain among the most frequently prescribed drugs and constitute a cornerstone in the prevention of cardiovascular disease. However, muscle symptoms are often reported from patients on statins. Muscle symptoms are frequently reported as adverse events associated with statin therapy.Areas covered: In the present narrative review, statin-associated muscle pain is discussed. It elucidates potential mechanisms and possible targets for management.Expert opinion: In general, the evidence in support of muscle pain caused by statins is in some cases equivocal and not particularly strong. Reported symptoms are difficult to quantify. Rarely is it possible to establish a causal link between statins and muscle pain. In randomized controlled trials, statins are well tolerated, and muscle-pain related side-effects is similar to placebo. There are also nocebo effects of statins. Exchange of statin may be beneficial although all statins have been associated with muscle pain. In some patients reduction of dose is worth trying, especially in primary prevention Although the benefits of statins outweigh potential risks in the vast majority of cases, careful clinical judgment may be necessary in certain cases to manage potential side effects on an individual basis.

Lyso-diacylglyceryltrimethylhomoserine (lyso-DGTS) isolated from Nannochloropsis microalgae improves high-density lipoprotein (HDL) functions

Many population studies have shown that blood concentrations of high-density lipoprotein (HDL) cholesterol are inversely correlated with risk of cardiovascular disease (CVD). However, in recent studies, increasing blood HDL cholesterol concentrations failed to reduce CVD events. On the other hand, studies suggest that improving HDL quality can be a more efficient tool for assessing atherosclerotic risk than simply measuring blood HDL cholesterol concentration. Thus, improving HDL activity using natural substances might be a useful therapeutic approach to reducing CVD risk. We previously isolated a novel active compound from Nannochloropsis microalgae termed lyso-diacylglyceryltrimethylhomoserine (lyso-DGTS), which increased activity of paraoxonase 1, the main antioxidant enzyme associated with HDL. Here we examined the effect of lyso-DGTS on HDL quality and function. Tryptophan-fluorescence-quenching assay showed that lyso-DGTS interacts spontaneously with the entire HDL lipoprotein and with apolipoprotein A1 (ApoA1), the major structural and functional HDL protein, with high affinity (K_a = 2.17 × 10⁴  M^-1 at 37°C). Lyso-DGTS added to HDL and to ApoA1 increased cholesterol efflux from macrophage cells, the main antiatherogenic function of HDL, dose-dependently, and significantly increased HDL's ability to induce nitric oxide production from endothelial cells. In-vivo supplementation of lyso-DGTS to the circulation of mice fed a high-fat diet via osmotic mini-pumps implanted subcutaneously enhanced HDL anti-inflammatory effect significantly as compared to controls. Our findings suggest that lyso-DGTS may have a beneficial effect in decreasing atherosclerosis risk by interacting with HDL particles and improving their quality and antiatherogenic functions.

Statin Safety and Associated Adverse Events: A Scientific Statement From the American Heart Association

One in 4 Americans >40 years of age takes a statin to reduce the risk of myocardial infarction, ischemic stroke, and other complications of atherosclerotic disease. The most effective statins produce a mean reduction in low-density lipoprotein cholesterol of 55% to 60% at the maximum dosage, and 6 of the 7 marketed statins are available in generic form, which makes them affordable for most patients. Primarily using data from randomized controlled trials, supplemented with observational data where necessary, this scientific statement provides a comprehensive review of statin safety and tolerability. The review covers the general patient population, as well as demographic subgroups, including the elderly, children, pregnant women, East Asians, and patients with specific conditions such as chronic disease of the kidney and liver, human immunodeficiency viral infection, and organ transplants. The risk of statin-induced serious muscle injury, including rhabdomyolysis, is <0.1%, and the risk of serious hepatotoxicity is ≈0.001%. The risk of statin-induced newly diagnosed diabetes mellitus is ≈0.2% per year of treatment, depending on the underlying risk of diabetes mellitus in the population studied. In patients with cerebrovascular disease, statins possibly increase the risk of hemorrhagic stroke; however, they clearly produce a greater reduction in the risk of atherothrombotic stroke and thus total stroke, as well as other cardiovascular events. There is no convincing evidence for a causal relationship between statins and cancer, cataracts, cognitive dysfunction, peripheral neuropathy, erectile dysfunction, or tendonitis. In US clinical practices, roughly 10% of patients stop taking a statin because of subjective complaints, most commonly muscle symptoms without raised creatine kinase. In contrast, in randomized clinical trials, the difference in the incidence of muscle symptoms without significantly raised creatinine kinase in statin-treated compared with placebo-treated participants is <1%, and it is even smaller (0.1%) for patients who discontinued treatment because of such muscle symptoms. This suggests that muscle symptoms are usually not caused by pharmacological effects of the statin. Restarting statin therapy in these patients can be challenging, but it is important, especially in patients at high risk of cardiovascular events, for whom prevention of these events is a priority. Overall, in patients for whom statin treatment is recommended by current guidelines, the benefits greatly outweigh the risks.

Statin Toxicity

There is now overwhelming evidence to support lowering LDL-c (low-density lipoprotein cholesterol) to reduce cardiovascular morbidity and mortality. Statins are a class of drugs frequently prescribed to lower cholesterol. However, in spite of their wide-spread use, discontinuation and nonadherence remains a major gap in both the primary and secondary prevention of atherosclerotic cardiovascular disease. The major reason for statin discontinuation is because of the development of statin-associated muscle symptoms, but a range of other statin-induced side effects also exist. Although the mechanisms behind these side effects have not been fully elucidated, there is an urgent need to identify those at increased risk of developing side effects as well as provide alternative treatment strategies. In this article, we review the mechanisms and clinical importance of statin toxicity and focus on the evaluation and management of statin-associated muscle symptoms.

Statin treatment after acute coronary syndrome: Adherence and reasons for non-adherence in a randomized controlled intervention trial

Studies of secondary prevention for cardiovascular disease show low fulfilment of guideline-recommended targets. This study explored whether nurse-led follow-up could increase adherence to statins over time and reasons for discontinuation. All patients admitted for acute coronary syndrome at Östersund hospital between 2010-2014 were screened for the randomized controlled NAILED-ACS trial. The trial comprises two groups, one with nurse-led annual follow-up and medical titration by telephone to reach set intervention targets and one with usual care. All discontinuations of statins were recorded prospectively for at least 36 months and categorized as avoidable or unavoidable. Kaplan-Meier estimates were conducted for first and permanent discontinuations. Predictors for discontinuation were analysed using multivariate Cox regression, statin type and mean LDL-C at end of follow-up. Female gender was a predictor for discontinuation. Allocation in the intervention group predicted increased risk for a first but decreased risk for permanent discontinuation. A nurse-led telemedical secondary prevention programme in a relatively unselected ACS cohort leads to increased adherence to statins over time, greater percentage on potent treatment and lower LDL-C compared to usual care. An initially increased tendency toward early discontinuation in the intervention group stresses the importance of a longer duration of structured follow-up.

Reasons for disparity in statin adherence rates between clinical trials and real-world observations: a review

With statins, the reported rate of adverse events differs widely between randomized clinical trials (RCTs) and observations in clinical practice, the rates being 1-2% in RCTs vs. 10-20% in the so-called real world. One possible explanation is the claim that RCTs mostly use a run-in period with a statin. This would exclude intolerant patients from remaining in the trial and therefore favour a bias towards lower rates of intolerance. We here review data from RCTs with more than 1000 participants with and without a run-in period, which were included in the Cholesterol Treatment Trialists Collaboration. Two major conclusions arise: (i) the majority of RCTs did not have a test dose of a statin in the run-in phase. (ii) A test dose in the run-in phase was not associated with a significantly improved adherence rate within that trial when compared to trials without a test dose. Taken together, the RCTs of statins reviewed here do not suggest a bias towards an artificially higher adherence rate because of a run-in period with a test dose of the statin. Other possible explanations for the apparent disparity between RCTs and real-world observations are also included in this review albeit mostly not supported by scientific data.

Lyso-DGTS lipid isolated from microalgae enhances PON1 activities in vitro and in vivo, increases PON1 penetration into macrophages and decreases cellular lipid accumulation

High-density lipoprotein (HDL) plays an important role in preventing atherosclerosis. The antioxidant effect of HDL is mostly associated with paraoxonase 1 (PON1) activity. Increasing PON1 activity using nutrients might improve HDL function and quality and thus, decrease atherosclerotic risk. We previously isolated and identified a novel active compound, lyso-DGTS (C20:5,0) from Nannochloropsis sp. ethanol extract. In the present study, its effect on PON1 activities was examined and the mechanism by which the compound affects PON1 activity was explored. Lyso-DGTS elevated recombinant PON1 (rePON1) lactonase and esterase activities in a dose- and time-responsive manner, and further stabilized and preserved rePON1 lactonase activity. Incubation of lyso-DGTS with human serum for 4 h at 37 °C also increased PON1 lactonase activity in a dose-responsive manner. Using tryptophan-fluorescence-quenching assay, lyso-DGTS was found to interact with rePON1 spontaneously with negative free energy (ΔG = -22.87 kJ mol^-1 at 25 °C). Thermodynamic parameters and molecular modeling calculations showed that the main interaction of lyso-DGTS with the enzyme is through a hydrogen bond with supporting van der Waals interactions. Furthermore, lyso-DGTS significantly increased rePON1 influx into macrophages and prevented lipid accumulation in macrophages stimulated with oxidized low-density lipid dose-dependently. In vivo supplementation of lyso-DGTS to the circulation of mice fed a high-fat diet via osmotic mini-pumps implanted subcutaneously significantly increased serum PON1 lactonase activity and decreased serum glucose concentrations to the level of mice fed a normal diet. Our findings suggest a beneficial effect of lyso-DGTS on increasing PON1 activity and thus, improving HDL quality and atherosclerotic risk factors. © 2018 BioFactors, 44(3):299-310, 2018.

Atorvastatin and lovastatin, but not pravastatin, increased cellular complex formation between PCSK9 and the LDL receptor in human hepatocyte-like C3A cells

Statins are the first-line treatment for hypercholesterolemic patients. Herein, the effects of three statins on complex formation between proprotein convertase subtilisin-kexin 9 (PCSK9) and the low density lipoprotein receptor (LDLR), a critical step for the PCSK9-dependent degradation of LDLR in the lysosome, were examined. Human hepatocyte-like C3A cells grown in control (containing 10% fetal bovine serum) or MITO+ (supplemented with BD™ MITO + serum extender) medium were also treated with atorvastatin (Atorv), lovastatin (Lov), or pravastatin (Prav) for 24 h. RNA and protein expression studies and determinations of PCSK9/LDLR complex formation were performed. As expected, the statins increased the expression of PCSK9 and LDLR independently of the medium employed. Interestingly, Atov and Lov caused increases in PCSK9/LDLR complex formation, whereas Prav decreased complex formation when compared to cells treated without drugs. These results may explain why Prav works better for statin intolerant patients than other statins such as Atorv and Lov.

CKM Glu83Gly Is Associated With Blunted Creatine Kinase Variation, but Not With Myalgia

BACKGROUND

To test the association of a recently reported variant in the creatine kinase (CK) muscle gene, CKM Glu83Gly (rs11559024) with constitutive creatine phosphokinase (CK) levels, CK variation, and inducibility. Given the diagnostic importance of CK in determining muscle damage, we tested the association of the variant with myalgia.

METHODS AND RESULTS

Meta-analysis between longitudinal cohort GoDARTS (Genetics of Diabetes Audit and Research, Tayside Scotland), minor allele frequency (=0.02), and randomized clinical trial (JUPITER [Justification for the Use of Statins in Primary Prevention: An Intervention Trial Evaluating Rosuvastatin], minor allele frequency=0.018) was used to replicate the association with baseline CK measures. GoDARTS was used to study the relationship with CK variability. Myalgia was studied in JUPITER trial participants. Baseline and SDs of CK were on average 18% (P value=6×10-63) and 24% (P value=2×10-5) lower for carriers of the variant, respectively. The variant was not associated with myalgia (odds ratio, 0.84; 95% confidence interval, 0.52-1.38).

CONCLUSIONS

This study highlights that a genetic factor known to be associated with constitutive CK levels is also associated with CK variability and inducibility. This is discussed in the context of evidence to suggest that the variant has an impact on inducibility of CK by trauma through a previously reported case of a homozygous carrier. However, the lack of association between the variant and myalgia suggests that it cannot reliably be used as a biomarker for muscle symptoms.

Interpretation of the evidence for the efficacy and safety of statin therapy

This Review is intended to help clinicians, patients, and the public make informed decisions about statin therapy for the prevention of heart attacks and strokes. It explains how the evidence that is available from randomised controlled trials yields reliable information about both the efficacy and safety of statin therapy. In addition, it discusses how claims that statins commonly cause adverse effects reflect a failure to recognise the limitations of other sources of evidence about the effects of treatment. Large-scale evidence from randomised trials shows that statin therapy reduces the risk of major vascular events (ie, coronary deaths or myocardial infarctions, strokes, and coronary revascularisation procedures) by about one-quarter for each mmol/L reduction in LDL cholesterol during each year (after the first) that it continues to be taken. The absolute benefits of statin therapy depend on an individual's absolute risk of occlusive vascular events and the absolute reduction in LDL cholesterol that is achieved. For example, lowering LDL cholesterol by 2 mmol/L (77 mg/dL) with an effective low-cost statin regimen (eg, atorvastatin 40 mg daily, costing about £2 per month) for 5 years in 10 000 patients would typically prevent major vascular events from occurring in about 1000 patients (ie, 10% absolute benefit) with pre-existing occlusive vascular disease (secondary prevention) and in 500 patients (ie, 5% absolute benefit) who are at increased risk but have not yet had a vascular event (primary prevention). Statin therapy has been shown to reduce vascular disease risk during each year it continues to be taken, so larger absolute benefits would accrue with more prolonged therapy, and these benefits persist long term. The only serious adverse events that have been shown to be caused by long-term statin therapy-ie, adverse effects of the statin-are myopathy (defined as muscle pain or weakness combined with large increases in blood concentrations of creatine kinase), new-onset diabetes mellitus, and, probably, haemorrhagic stroke. Typically, treatment of 10 000 patients for 5 years with an effective regimen (eg, atorvastatin 40 mg daily) would cause about 5 cases of myopathy (one of which might progress, if the statin therapy is not stopped, to the more severe condition of rhabdomyolysis), 50-100 new cases of diabetes, and 5-10 haemorrhagic strokes. However, any adverse impact of these side-effects on major vascular events has already been taken into account in the estimates of the absolute benefits. Statin therapy may cause symptomatic adverse events (eg, muscle pain or weakness) in up to about 50-100 patients (ie, 0·5-1·0% absolute harm) per 10 000 treated for 5 years. However, placebo-controlled randomised trials have shown definitively that almost all of the symptomatic adverse events that are attributed to statin therapy in routine practice are not actually caused by it (ie, they represent misattribution). The large-scale evidence available from randomised trials also indicates that it is unlikely that large absolute excesses in other serious adverse events still await discovery. Consequently, any further findings that emerge about the effects of statin therapy would not be expected to alter materially the balance of benefits and harms. It is, therefore, of concern that exaggerated claims about side-effect rates with statin therapy may be responsible for its under-use among individuals at increased risk of cardiovascular events. For, whereas the rare cases of myopathy and any muscle-related symptoms that are attributed to statin therapy generally resolve rapidly when treatment is stopped, the heart attacks or strokes that may occur if statin therapy is stopped unnecessarily can be devastating.

Protocol for analyses of adverse event data from randomized controlled trials of statin therapy

The Cholesterol Treatment Trialists' (CTT) Collaboration was originally established to conduct individual participant data meta-analyses of major vascular events, cause-specific mortality, and site-specific cancers in large, long-term, randomized trials of statin therapy (and other cholesterol-modifying treatments). The results of the trials of statin therapy and their associated meta-analyses have shown that statins significantly reduce the risk of major vascular events without any increase in the risk of nonvascular causes of death or of site-specific cancer, but do produce small increases in the incidence of myopathy, diabetes, and, probably, hemorrhagic stroke. The CTT Collaboration has not previously sought data on other outcomes, and so a comprehensive meta-analysis of all adverse events recorded in each of the eligible trials has not been conducted. This protocol prospectively describes plans to extend the CTT meta-analysis data set so as to provide a more complete understanding of the nature and magnitude of any other effects of statin therapy.