Effects of Non-statin Lipid-Modifying Agents on Cardiovascular Morbidity and Mortality Among Statin-Treated Patients: A Systematic Review and Network Meta-Analysis

Projected Cost Savings With Optimal Medication Adherence in Patients With Cardiovascular Disease Requiring Lipid-Lowering Therapy: A Multinational Economic Evaluation Study

BACKGROUND

Poor adherence to chronic cardiovascular treatments can impede targeted clinical outcomes. This study estimates the potential benefits of improving adherence among patients with cardiovascular disease requiring secondary prevention in Mexico, Thailand, and China.

METHODS AND RESULTS

We performed Markov model simulation for patients with cardiovascular disease in 3 countries from health care and societal perspectives over a lifetime horizon. Two scenarios were compared: (1) optimal adherence based on a meta-analysis of 51 randomized controlled trials and (2) status quo. The association between adherence and cardiovascular disease outcomes derives from a dose-response meta-analysis of 4 051 338 patients. Outcomes include the accumulated number of cardiovascular events and associated costs in 2022 US dollars, life years, and quality-adjusted life years. Optimal adherence could prevent 42 (95% credible interval [CrI], 29-56) cardiovascular events in Mexico, 34 (95% CrI, 24-50) in Thailand, and 63 (95% CrI, 43-89) in China per 1000 patients over a lifetime. Incremental effectiveness per patient was 0.60 (95% CrI, 0.47-0.74) life-years in Mexico, 0.68 (95% CrI, 0.37-0.94) quality-adjusted life years in Thailand, and 0.93 (95% CrI, 0.44-1.27) quality-adjusted life years in China. Cost savings from societal perspective amounted to $412 (95% CrI, $211-$723), $316 (95% CrI, $187-$541), and $700 (95% CrI, $355-$1144) per patient for Mexico, Thailand, and China, respectively. Findings remained cost saving in deterministic and probabilistic sensitivity analyses.

CONCLUSIONS

Achieving optimal adherence in patients with cardiovascular disease requiring lipid-lowering therapy saves costs and improves health outcomes in Mexico, Thailand, and China. These findings support national health care systems implementing strategies to improve adherence in these countries.

Safety and Effectiveness of High-Intensity Statins Versus Low/Moderate-Intensity Statins Plus Ezetimibe in Patients With Atherosclerotic Cardiovascular Disease for Reaching LDL-C Goals: A Systematic Review and Meta-Analysis

BACKGROUND

It remains controversial whether adding ezetimibe to low/moderate-intensity statins has a more beneficial impact on the treatment efficacy and safety of patients with existing atherosclerotic cardiovascular disease (ASCVD) compared to high-intensity statin regimens.

HYPOTHESIS

A combination of low/moderate-intensity statins plus ezetimibe might be more effective and safer than high-intensity statin monotherapy.

METHODS

We searched databases for randomized controlled trials comparing lipid profile alterations, drug-related adverse events, and MACE components between high-intensity statin monotherapy and low/moderate-intensity statin plus ezetimibe combination therapy. Pooled risk ratios (RR), mean differences (MD), and 95% confidence intervals (95% CI) were estimated using a random-effects model.

RESULTS

Our comprehensive search resulted in 32 studies comprising 6162 patients treated with monotherapy against 5880 patients on combination therapy. Combination therapy was more effective in reducing low-density lipoprotein cholesterol (LDL-C) levels compared to monotherapy (MD = -6.6, 95% CI: -10.6 to -2.5); however, no significant differences were observed in other lipid parameters. Furthermore, the combination therapy group experienced a lower risk of myalgia (RR = 0.27, 95% CI: 0.13-0.57) and discontinuation due to adverse events (RR = 0.61, 95% CI: 0.51-0.74). The occurrence of MACE was similar between the two treatment groups.

CONCLUSIONS

Adding ezetimibe to low/moderate-intensity statins resulted in a greater reduction in LDL-C levels, a lower rate of myalgia, and less drug discontinuation compared to high-intensity statin monotherapy in patients with existing cardiovascular disease. However, according to our meta-analysis, the observed reduction in LDL-C levels in the combination group did not correlate with a reduction in MACE compared to the high-intensity statin group.

PCSK9 and Lipid Metabolism: Genetic Variants, Current Therapies, and Cardiovascular Outcomes

Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a crucial role in the modulation of lipid metabolism as a critical negative regulator of hepatic low-density lipoprotein receptor (LDLR) levels and circulating low-density lipoprotein (LDL) clearance. Numerous gain-of-function (GOF) mutations in PCSK9 have been identified as causing familial hypercholesterolemia (FH) by reducing LDLR levels, and loss-of-function (LOF) mutations associated with a hypercholesterolemia phenotype protective against atherosclerosis. PCSK9 represents an example of successful translational research resulting in the identification of PCSK9 as a major drug target for a lipid-lowering therapy. To explore the genetic constitution of PCSK9 and its biologic role, in this review, we summarize the current evidence of clinically significant PCSK9 genetic variants involved in lipid metabolism as well as emphasize the importance of PCSK9 inhibition for the improvement of cardiovascular outcomes by conducting a meta-analysis of the available data on the incidence of cardiovascular disease events.

Lipid-lowering therapies for cardiovascular disease prevention and management in primary care: PEER umbrella systematic review of systematic reviews

OBJECTIVE

To assess the benefits and harms of lipid-lowering therapies used to prevent or manage cardiovascular disease including bile acid sequestrants (BAS), ezetimibe, fibrates, niacin, omega-3 supplements, proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors, and statins.

DATA SOURCES

MEDLINE, the Cochrane Database of Systematic Reviews, and a grey literature search.

STUDY SELECTION

Systematic reviews of randomized controlled trials published between January 2017 and March 2022 looking at statins, ezetimibe, PCSK9 inhibitors, fibrates, BAS, niacin, and omega-3 supplements for preventing cardiovascular outcomes were selected. Outcomes of interest included major adverse cardiovascular events (MACE), cardiovascular mortality, all-cause mortality, and adverse events.

SYNTHESIS

A total of 76 systematic reviews were included. Four randomized controlled trials were also included for BAS because no efficacy systematic review was identified. Statins significantly reduced MACE (6 systematic reviews; median risk ratio [RR]=0.74; interquartile range [IQR]=0.71 to 0.76), cardiovascular mortality (7 systematic reviews; median RR=0.85, IQR=0.83 to 0.86), and all-cause mortality (8 systematic reviews; median RR=0.91, IQR=0.88 to 0.92). Major adverse cardiovascular events were also significantly reduced by ezetimibe (3 systematic reviews; median RR=0.93, IQR=0.93 to 0.94), PCSK9 inhibitors (14 systematic reviews; median RR=0.84, IQR=0.83 to 0.87), and fibrates (2 systematic reviews; mean RR=0.86), but these interventions had no effect on cardiovascular or all-cause mortality. Fibrates had no effect on any cardiovascular outcomes when added to a statin. Omega-3 combination supplements had no effect on MACE or all-cause mortality but significantly reduced cardiovascular mortality (5 systematic reviews; median RR=0.93, IQR=0.93 to 0.94). Eicosapentaenoic acid ethyl ester alone significantly reduced MACE (1 systematic review, RR=0.78) and cardiovascular mortality (2 systematic reviews; RRs of 0.82 and 0.82). In primary cardiovascular prevention, only statins showed consistent benefits on MACE (6 systematic reviews; median RR=0.75, IQR=0.73 to 0.78), cardiovascularall-cause mortality (7 systematic reviews, median RR=0.83, IQR=0.81 to 0.90), and all-cause mortality (8 systematic reviews; median RR=0.91, IQR=0.87 to 0.91).

CONCLUSION

Statins have the most consistent evidence for the prevention of cardiovascular complications with a relative risk reduction of about 25% for MACE and 10% to 15% for mortality. The addition of ezetimibe, a PCSK9 inhibitor, or eicosapentaenoic acid ethyl ester to a statin provides additional MACE risk reduction but has no effect on all-cause mortality.

Interaction of Cardiovascular Nonmodifiable Risk Factors, Comorbidities and Comedications With Ischemia/Reperfusion Injury and Cardioprotection by Pharmacological Treatments and Ischemic Conditioning

Preconditioning, postconditioning, and remote conditioning of the myocardium enhance the ability of the heart to withstand a prolonged ischemia/reperfusion insult and the potential to provide novel therapeutic paradigms for cardioprotection. While many signaling pathways leading to endogenous cardioprotection have been elucidated in experimental studies over the past 30 years, no cardioprotective drug is on the market yet for that indication. One likely major reason for this failure to translate cardioprotection into patient benefit is the lack of rigorous and systematic preclinical evaluation of promising cardioprotective therapies prior to their clinical evaluation, since ischemic heart disease in humans is a complex disorder caused by or associated with cardiovascular risk factors and comorbidities. These risk factors and comorbidities induce fundamental alterations in cellular signaling cascades that affect the development of ischemia/reperfusion injury and responses to cardioprotective interventions. Moreover, some of the medications used to treat these comorbidities may impact on cardioprotection by again modifying cellular signaling pathways. The aim of this article is to review the recent evidence that cardiovascular risk factors as well as comorbidities and their medications may modify the response to cardioprotective interventions. We emphasize the critical need for taking into account the presence of cardiovascular risk factors as well as comorbidities and their concomitant medications when designing preclinical studies for the identification and validation of cardioprotective drug targets and clinical studies. This will hopefully maximize the success rate of developing rational approaches to effective cardioprotective therapies for the majority of patients with multiple comorbidities. SIGNIFICANCE STATEMENT: Ischemic heart disease is a major cause of mortality; however, there are still no cardioprotective drugs on the market. Most studies on cardioprotection have been undertaken in animal models of ischemia/reperfusion in the absence of comorbidities; however, ischemic heart disease develops with other systemic disorders (e.g., hypertension, hyperlipidemia, diabetes, atherosclerosis). Here we focus on the preclinical and clinical evidence showing how these comorbidities and their routine medications affect ischemia/reperfusion injury and interfere with cardioprotective strategies.

Cost-effectiveness of Ezetimibe plus statin lipid-lowering therapy: A systematic review and meta-analysis of cost-utility studies

In addition to statin therapy, Ezetimibe, a non-statin lipid-modifying agent, is increasingly used to reduce low-density lipoprotein cholesterol and atherosclerotic cardiovascular disease risk. Literature suggests the clinical effectiveness of Ezetimibe plus statin (EPS) therapy; however, primary evidence on its economic effectiveness is inconsistent. Hence, we pooled incremental net benefit to synthesise the cost-effectiveness of EPS therapy. We identified economic evaluation studies reporting outcomes of EPS therapy compared with other lipid-lowering therapeutic agents or placebo by searching PubMed, Embase, Scopus, and Tufts Cost-Effective Analysis registry. Using random-effects meta-analysis, we pooled Incremental Net Benefit (INB) in the US $ with a 95% confidence interval (CI). We used the modified economic evaluations bias checklist and GRADE quality assessment for quality appraisal. The pooled INB from twenty-one eligible studies showed that EPS therapy was significantly cost-effective compared to other lipid-lowering therapeutic agents or placebo. The pooled INB (95% CI) was $4,274 (621 to 7,927), but there was considerable heterogeneity (I² = 84.21). On subgroup analysis EPS therapy is significantly cost-effective in high-income countries [$4,356 (621 to 8,092)], for primary prevention [$4,814 (2,523 to 7,106)], and for payers’ perspective [$3,255 (571 to 5,939)], and from lifetime horizon [$4,571 (746 to 8,395)]. EPS therapy is cost-effective compared to other lipid-lowering therapeutic agents or placebo in high-income countries and for primary prevention. However, there is a dearth of evidence from lower-middle-income countries and the societal perspective.

Availability of bioactive flax lignan from foods and supplements

Hyperlipidemia, high levels of blood lipids including cholesterol and triglycerides, is a major risk factor for cardiovascular disease. Traditional treatments of hyperlipidemia often include lifestyle changes and pharmacotherapy. Recently, flaxseed has been approved as a nutrient that lowers blood lipids. Several metabolites of flaxseed lignan secoisolariciresinol diglucoside (SDG), have been identified that reduce blood lipids. SDG is present in flaxseed hull as an ester-linked copolymer with 3-hydroxy-3-methylglutaric acid (HMGA). However, purification processes involved in hydrolysis of the copolymer and enriching SDG are often expensive. The natural copolymer of SDG with HMGA (SDG polymer) is a source of bioactive compounds useful in prophylaxis of hypercholesterolemia. After consumption of the lignan copolymer, SDG and HMGA are released in the stomach and small intestines. SDG is metabolized to secoisolariciresinol, enterolactone and enterodiol, the bioactive forms of mammalian lignans. These metabolites are then distributed throughout the body where they accumulate in the liver, kidney, skin, other tissues, and organs. Successively, these metabolites reduce blood lipids including cholesterol, triglycerides, low density lipoprotein cholesterol, and lipid peroxidation products. In this review, the metabolism and efficacies of flaxseed-derived enriched SDG and SDG polymer will be discussed.

Safety of ezetimibe in lipid-lowering treatment: systematic review and meta-analysis of randomised controlled trials and cohort studies

OBJECTIVE

To determine the harms of ezetimibe in people who need lipid-lowering treatment.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Randomised controlled trials and cohort studies.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies comparing ezetimibe with placebo, standard care, or other lipid-lowering agents in people who need lipid-lowering treatment with a follow-up duration of at least six months (or 24 weeks). The relative effects for potential harms of ezetimibe were pooled by use of random effect pairwise meta-analyses for randomised controlled trials and the evidence from observational studies was narratively summarised. The certainty of evidence was assessed using the Grading of Recommendation Assessment, Development, and Evaluation.

RESULTS

48 randomised controlled trials with 28 444 participants (median follow-up 34 weeks, range 24-312 weeks) and four observational studies with 1667 participants (median follow-up 282 weeks, range 72-400 weeks) were included. The meta-analyses of randomised trials showed moderate to high certainty that ezetimibe was not associated with cancer (relative risk 1.01; 95% confidence interval 0.92 to 1.11), fractures (0.90; 0.74 to 1.10), discontinuation due to any adverse event (0.87; 0.74 to 1.03), gastrointestinal adverse events leading to discontinuation (1.34; 0.58 to 3.08), myalgia or muscular pain leading to discontinuation (0.82; 0.51 to 1.33), neurocognitive events (1.48; 0.58 to 3.81), or new-onset diabetes (0.88; 0.61 to 1.28). The narrative analysis of observational studies provided consistent findings. No credible subgroup effects were identified for the harm outcomes, including shorter versus longer follow-up duration of trials.

CONCLUSIONS

Ezetimibe results in little to no difference in adverse events or other undesirable effects compared with placebo, usual care or other lipid-lowering agents.

REVIEW REGISTRATION

PROSPERO CRD42020187437.

Trends in the Utilization of Lipid-Lowering Medications in Australia: An Analysis of National Pharmacy Claims Data

Lipid-lowering medications comprise standard of care in the prevention of cardiovascular disease. This study examined the trends in the utilization of statin and non-statin medications in the Australian general population between 2013 and 2019. Pharmacoepidemiological analyses were performed using pharmacy dispensing data from Australian Pharmaceutical Benefits Scheme. One-year prevalence and incidence of statin and non-statin prescribing patterns were reported, and relative variations in prescribing examined via Poisson regression modelling. The one-year prevalence of statins' prescriptions decreased between 2013-2019 by 5.5% (from 25.0%-19.5%). Females were less likely than males to be prescribed statins (rate ratio [RR]=0.90, 95% confidence interval [CI] 0.89-0.91). The one-year prevalence of ezetimibe alone, and in combination with statins, increased consistently from 2013-2019 from 1.5%-3.6% (P<0.01) and 0.1%-1.1% (P<0.01), respectively. The prevalence was higher among those aged 61-80 years (RR=1.20, 95%CI 1.10-1.21) and those aged older than 80 years (RR=1.34, 95%CI 1.22-1.47), when compared to people aged <60 years. The incidence of ezetimibe prescriptions was highest in people aged 61-80 years (RR=1.36, 95%CI 1.31-1.41) compared to those aged <60 years. The one-year prevalence of proprotein convertase subtilisin/kexin type 9 inhibitor prescriptions was highest among those aged 46-60 years (RR=1.24, 95%CI 0.97-4.97) compared to people aged <46 and >60 years. Females were less likely than males to be prescribed a proprotein convertase subtilisin/kexin type 9 inhibitor (RR=0.87, 95%CI 0.75-0.98). Statins remain the most prevalent lipid-lowering medication prescribed in Australia. The prescribing of non-statin medications remains low, but is increasing.

PCSK9 in Myocardial Infarction and Cardioprotection: Importance of Lipid Metabolism and Inflammation

Extensive evidence from epidemiologic, genetic, and clinical intervention studies has indisputably shown that elevated low-density lipoprotein cholesterol (LDL-C) concentrations play a central role in the pathophysiology of atherosclerotic cardiovascular disease. Apart from LDL-C, also triglycerides independently modulate cardiovascular risk. Reduction of proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as a therapeutic target for reducing plasma LDL-C, but it is also associated with a reduction in triglyceride levels potentially through modulation of the expression of free fatty acid transporters. Preclinical data indicate that PCSK9 is up-regulated in the ischaemic heart and decreasing PCSK9 expression impacts on infarct size, post infarct inflammation and remodeling as well as cardiac dysfunction following ischaemia/reperfusion. Clinical data support that notion in that PCSK9 inhibition is associated with reductions in the incidence of myocardial infarction, stroke, and coronary revascularization and an improvement of endothelial function in subjects with increased cardiovascular risk. The aim of the current review is to summarize the current knowledge on the importance of free fatty acid metabolism on myocardial ischaemia/reperfusion injury and to provide an update on recent evidence on the role of hyperlipidemia and PCSK9 in myocardial infarction and cardioprotection.

Lipoproteins and lipids in cardiovascular disease: from mechanistic insights to therapeutic targeting

With cardiovascular disease being the leading cause of morbidity and mortality worldwide, effective and cost-efficient therapies to reduce cardiovascular risk are highly needed. Lipids and lipoprotein particles crucially contribute to atherosclerosis as underlying pathology of cardiovascular disease and influence inflammatory processes as well as function of leukocytes, vascular and cardiac cells, thereby impacting on vessels and heart. Statins form the first-line therapy with the aim to block cholesterol synthesis, but additional lipid-lowering drugs are sometimes needed to achieve low-density lipoprotein (LDL) cholesterol target values. Furthermore, beyond LDL cholesterol, also other lipid mediators contribute to cardiovascular risk. This review comprehensively discusses low- and high-density lipoprotein cholesterol, lipoprotein (a), triglycerides as well as fatty acids and derivatives in the context of cardiovascular disease, providing mechanistic insights into their role in pathological processes impacting on cardiovascular disease. Also, an overview of applied as well as emerging therapeutic strategies to reduce lipid-induced cardiovascular burden is provided.

Hypolipidemic Effects of β-Glucans, Mannans, and Fucoidans: Mechanism of Action and Their Prospects for Clinical Application

The search for lipid-lowering drugs is important for clinical medicine. This review summarizes our research findings regarding the hypolipidemic activity of polysaccharides. There are several validated agents altering lipid levels which reduce the risk of atherosclerotic cardiovascular events. Nonetheless, for many people, the risk of such an event remains unacceptably high despite treatment with these agents. This situation has prompted the search for new therapies to reduce the residual cardiovascular risk. The lipid-lowering effect of β-glucans consumed with food was demonstrated in patients with atherosclerosis. The mechanism of the protective effect of β-glucans is poorly studied. The effects of β-glucans are mediated by Toll-like receptors, by dectin-1, and possibly by other receptors. Nevertheless, the mechanism of the protective action of β-glucan in lipemic mice has been studied insufficiently. This review will present up-to-date information regarding experimental hypolipidemic polysaccharide compounds that hold promise for medicine. Phagocyte-specific chitotriosidase in humans contributes to innate immune responses against chitin-containing fungi. This enzyme has been first described in patients with Gaucher disease and serves as an important diagnostic biomarker. It has been reported that, in mice, chitin particles of certain size are recognized by macrophages through Toll-like receptors, dectin-1, and to a lesser extent through mannose receptor.

Cost-Effectiveness Analysis of Non-Statin Lipid-Modifying Agents for Secondary Cardiovascular Disease Prevention Among Statin-Treated Patients in Thailand

BACKGROUND

Using non-statin lipid-modifying agents in combination with statin therapy provides additional benefits for cardiovascular disease (CVD) risk reduction, but their value for money has only been evaluated in high-income countries (HICs). Furthermore, studies mainly derive effectiveness data from a single trial or older meta-analyses.

OBJECTIVES

Our study used data from the most recent network meta-analysis (NMA) and local parameters to assess the cost effectiveness of non-statin agents in statin-treated patients with a history of CVD.

METHODS

A published Markov model was adopted to investigate lifetime outcomes: (1) number of recurrent CVD events prevented, (2) quality-adjusted life-years (QALYs) gained, (3) costs and (4) incremental cost-effectiveness ratios (ICERs) of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) and ezetimibe added to statin therapy. Event rates and effectiveness inputs were obtained from the NMA. Cost and utility data were gathered from published studies conducted in Thailand. A series of sensitivity analyses were performed.

RESULTS

Patients receiving PCSK9i and ezetimibe experienced fewer recurrent CVD events (number needed to treat [NNT] 17 and 30) and more QALYs (0.168 and 0.096 QALYs gained per person). However, under the societal perspective and at current acquisition costs in 2018, ICERs of both agents were $US1,223,995 and 27,361 per QALY gained, respectively. Based on threshold analyses, the costs need to be reduced by 97 and 85%, respectively, for PCSK9i and ezetimibe to be cost-effective.

CONCLUSIONS

Despite the proven effectiveness of PCSK9i and ezetimibe, the costs of these agents need to reduce to a much greater extent than in HICs to be cost-effective in Thailand.