An updated review of lipid-modifying therapy

Triglyceride and Triglyceride-Rich Lipoproteins in Atherosclerosis

Cardiovascular disease (CVD) is still the leading cause of death globally, and atherosclerosis is the main pathological basis of CVDs. Low-density lipoprotein cholesterol (LDL-C) is a strong causal factor of atherosclerosis. However, the first-line lipid-lowering drugs, statins, only reduce approximately 30% of the CVD risk. Of note, atherosclerotic CVD (ASCVD) cannot be eliminated in a great number of patients even their LDL-C levels meet the recommended clinical goals. Previously, whether the elevated plasma level of triglyceride is causally associated with ASCVD has been controversial. Recent genetic and epidemiological studies have demonstrated that triglyceride and triglyceride-rich lipoprotein (TGRL) are the main causal risk factors of the residual ASCVD. TGRLs and their metabolites can promote atherosclerosis via modulating inflammation, oxidative stress, and formation of foam cells. In this article, we will make a short review of TG and TGRL metabolism, display evidence of association between TG and ASCVD, summarize the atherogenic factors of TGRLs and their metabolites, and discuss the current findings and advances in TG-lowering therapies. This review provides information useful for the researchers in the field of CVD as well as for pharmacologists and clinicians.

Ceramides and other sphingolipids as drivers of cardiovascular disease

Increases in calorie consumption and sedentary lifestyles are fuelling a global pandemic of cardiometabolic diseases, including coronary artery disease, diabetes mellitus, cardiomyopathy and heart failure. These lifestyle factors, when combined with genetic predispositions, increase the levels of circulating lipids, which can accumulate in non-adipose tissues, including blood vessel walls and the heart. The metabolism of these lipids produces bioactive intermediates that disrupt cellular function and survival. A compelling body of evidence suggests that sphingolipids, such as ceramides, account for much of the tissue damage in these cardiometabolic diseases. In humans, serum ceramide levels are proving to be accurate biomarkers of adverse cardiovascular disease outcomes. In mice and rats, pharmacological inhibition or depletion of enzymes driving de novo ceramide synthesis prevents the development of diabetes, atherosclerosis, hypertension and heart failure. In cultured cells and isolated tissues, ceramides perturb mitochondrial function, block fuel usage, disrupt vasodilatation and promote apoptosis. In this Review, we discuss the body of literature suggesting that ceramides are drivers - and not merely passengers - on the road to cardiovascular disease. Moreover, we explore the feasibility of therapeutic strategies to lower ceramide levels to improve cardiovascular health.

Serum Metabolomics Reveals Underlying Mechanisms of Cholesterol-Lowering Effects of Oat Consumption: A Randomized Controlled Trial in a Mildly Hypercholesterolemic Population

INTRODUCTION

The purpose of this study is to examine the effects of oat supplementation on serum lipid in a population of adults with mild hypercholesterolemia and reveal the underlying mechanisms with serum untargeted metabolomics.

METHODS AND RESULTS

In this placebo-controlled trial, 62 participants from Nanjing, China, with mild elevations in cholesterol are randomly assigned to receive 80 g oats (containing 3 g beta-glucan) or rice daily for 45 days. Fasting blood samples are collected at the beginning, middle, and end of the trial. Compared with the rice group, oat consumption significantly decreases serum total cholesterol (TC) (-8.41%, p = 0.005), low-density lipoprotein cholesterol (LDL-c) (-13.93%, p = 0.001), and non high-density lipoprotein cholesterol (non-HDL-c) (-10.93%, p = 0.017) levels. There are no significant between-group differences in serum triglyceride (TG), apolipoprotein B (Apo B), glycated albumin, or fasting blood glucose levels. An orthogonal partial least squares discriminant analysis (OPLS-DA) suggests a clear separation in metabolic profiles between the groups after the intervention. Twenty-one metabolites in the oat group are significantly different from those in the rice group, among which 14 metabolites show a decreased trend. In comparison, seven metabolites show an increased trend. Correlations analysis from both groups indicate that most metabolites [e.g., sphinganine and phosphatidylcholine (PC)(20:5(5Z,8Z,11Z,14Z,17Z)/20:1(11Z))] have positive correlations with serum cholesterol levels. Kyoto Encyclopedia of Gene and Genomes pathway analysis suggests that oat consumption regulated glycerophospholipid, alanine, aspartate and glutamate, sphingolipid, and retinol metabolism.

CONCLUSION

Oat consumption has beneficial effects on serum lipids profiles. The underlying mechanisms involve glycerophospholipid, alanine, aspartate and glutamate, sphingolipid, and retinol metabolism in adults.

Bempedoic acid for high-risk patients with CVD as adjunct lipid-lowering therapy: A cost-effectiveness analysis

BACKGROUND

Bempedoic acid is a novel adenosine triphosphate citrate lyase inhibitor shown to reduce low density lipoprotein cholesterol when used as an adjunct lipid-lowering therapy in patients with high cardiovascular disease (CVD) risk.

OBJECTIVE

Our analysis aimed to determine the price at which bempedoic acid would be cost-effective from the Australian health care perspective.

METHODS

A Markov model was designed using data from the Cholesterol Lowering via Bempedoic Acid, an ACL-Inhibiting Regimen (CLEAR) Harmony trial, to model the clinical outcomes and costs of 1000 patients treated with bempedoic acid over a lifetime horizon. Relevant health states were "Alive with CVD," "Alive with recurrent CVD," and "Dead." With annual cycles, patients were at risk of a nonfatal myocardial infarction, coronary revascularization, and death from CVD or non-CVD causes. Costs and utilities were obtained from published sources. Outcomes of interest were the incremental cost-effectiveness ratios in terms of cost per quality-adjusted life year (QALY) gained and cost per year of life saved. Outcomes were discounted at 5% per annum.

RESULTS

Among 1000 individuals, bempedoic acid in addition to statin therapy was estimated to save 122 (discounted) years of life and 103 (discounted) QALYs compared with statin therapy alone. At an acquisition cost of AU$584.40 per year (USD$397.01), bempedoic acid would be considered cost-effective within the Australian setting, with an incremental cost-effectiveness ratio of AU$49,890 per QALY gained (USD$33,893) and AU$42,433 per year of life saved (USD$28,827).

CONCLUSIONS

Bempedoic acid may be cost-effective within the Australian health care setting at an annual acquisition price less than $600.

Inclisiran as Adjunct Lipid-Lowering Therapy for Patients with Cardiovascular Disease: A Cost-Effectiveness Analysis

BACKGROUND

Inclisiran inhibits hepatic synthesis of proprotein convertase subtilisin-kexin type 9 (PCSK9). The comparison of inclisiran with statin versus statin alone in the ORION-10 trial demonstrated significant reductions in low-density lipoprotein cholesterol (LDL-C). Our study explored whether the use of inclisiran with statin versus statin alone for secondary prevention of cardiovascular events is cost effective from the Australian healthcare perspective, based on the price of currently available PCSK9 inhibitors.

METHODS

A Markov model was developed based on the ORION-10 trial to model outcomes and costs incurred by patients over a lifetime analysis. The three health states were 'alive with cardiovascular disease (CVD)', 'alive with recurrent CVD', and 'dead'. Cost and utilities were estimated from published sources. The cost of inclisiran was estimated from the annual cost of evolocumab, a PCSK9 inhibitor currently available in Australia (AU$6334, based on 2020 data). Outcomes of interest were incremental cost-effectiveness ratios (ICERs) in terms of cost per quality-adjusted life-year (QALY) and cost per year of life saved (YoLS). All costs, QALYs and YoLS were discounted at 5% per annum in line with Australian standards.

RESULTS

Among 1000 subjects followed-up over a lifetime analysis, inclisiran with statin compared with statin alone prevented 235 non-fatal myocardial infarctions (NFMIs; 151 NFMI and 84 repeat NFMI cases) and 114 coronary revascularisation cases, and increased years of life by 0.549 (discounted) and QALYs by 0.468 (discounted). At an annual price of AU$6334, the net marginal cost was AU$58,965 per person. The above values equated to ICERs of AU$107,402 per YoLS and AU$125,732 per QALY gained. Assuming a willingness-to-pay threshold of AU$50,000, inclisiran would have to be priced 60% lower than other available PCSK9 inhibitors to be considered cost effective.

CONCLUSIONS

As an adjunct therapy to statin treatment in those who have persistently elevated LDL-C despite optimal statin therapy, inclisiran is effective in reducing cardiovascular events in patients with atherosclerotic CVD. Inclisiran is not cost effective from the Australian healthcare perspective, assuming acquisition costs of current PCSK9 inhibitors. The cost of inclisiran would have to be 60% lower than that of evolocumab.

NMR-based metabolomic profile of hypercholesterolemic human sera: Relationship with in vitro gene expression?

Hypercholesterolaemia is considered an important cause of atherosclerotic cardiovascular disease. In a previous investigation, we demonstrated that cultured hepatoma cells treated with hypercholesterolaemic sera compared with cells treated with normocholesterolaemic sera show overexpression of mRNAs related to mitochondrial 3-hydroxy-3-methylglutaryl-coenzyme A synthase (HMGCS2). In the present work, using an NMR metabolomic analysis, we demonstrate that the hypercholesterolaemic blood sera previously used to treat cultured hepatoma cells are characterized by a metabolomic profile that is significantly different from the normocholesterolaemic sera. Acetate, acetone, 2-hydroxybutyrate, cysteine, valine, and glutamine are the metabolites distinguishing the two groups. Abnormalities in the concentrations of these metabolites reflect alterations in energy-related pathways, such as pantothenate and CoA biosynthesis, pyruvate, glycolysis/gluconeogenesis, the citrate cycle, and ketone bodies. Regarding ketone bodies, the pathway is regulated by HMGCS2; therefore, serum samples previously found to be able to increase HMGCS2 mRNA levels in cultured cells also contain higher amounts of the metabolites of its encoded enzyme protein product.