Lipid-Lowering Agents

The art of healing hearts: Mastering advanced RNA therapeutic techniques to shape the evolution of cardiovascular medicine in biomedical science

Cardiovascular diseases (CVDs) are the leading cause of death worldwide and are associated with increasing financial health burden that requires research into novel therapeutic approaches. Since the early 2000s, the availability of next-generation sequencing techniques such as microRNAs, circular RNAs, and long non-coding RNAs have been proven as potential therapeutic targets for treating various CVDs. Therapeutics based on RNAs have become a viable option for addressing the intricate molecular pathways that underlie the pathophysiology of CVDs. We provide an in-depth analysis of the state of RNA therapies in the context of CVDs, emphasizing various approaches that target the various stages of the basic dogma of molecular biology to effect temporary or long-term changes. In this review, we summarize recent methodologies used to screen for novel coding and non-coding RNA candidates with diagnostic and treatment possibilities in cardiovascular diseases. These methods include single-cell sequencing techniques, functional RNA screening, and next-generation sequencing.Lastly, we highlighted the potential of using oligonucleotide-based chemical products such as modified RNA and RNA mimics/inhibitors for the treatment of CVDs. Moreover, there will be an increasing number of potential RNA diagnostic and therapeutic for CVDs that will progress to expand for years to come.

Remnant Cholesterol, Not LDL Cholesterol, Explains Peripheral Artery Disease Risk Conferred by apoB: A Cohort Study

BACKGROUND

Elevated apoB-containing lipoproteins (=remnants+LDLs [low-density lipoproteins]) are a major risk factor for atherosclerotic cardiovascular disease, including peripheral artery disease (PAD) and myocardial infarction. We tested the hypothesis that remnants and LDL both explain part of the increased risk of PAD conferred by elevated apoB-containing lipoproteins. For comparison, we also studied the risk of chronic limb-threatening ischemia and myocardial infarction.

METHODS

apoB, remnant cholesterol, and LDL cholesterol were measured in 93 461 individuals without statin use at baseline from the Copenhagen General Population Study (2003-2015). During up to 15 years of follow-up, 1207 had PAD, 552 had chronic limb-threatening ischemia, and 2022 had myocardial infarction in the Danish National Patient Registry. Remnant and LDL cholesterol were calculated from a standard lipid profile. Remnant and LDL particle counts were additionally measured with nuclear magnetic resonance spectroscopy in 25 347 of the individuals. Results were replicated in 302 167 individuals without statin use from the UK Biobank (2004-2010).

RESULTS

In the Copenhagen General Population Study, multivariable adjusted hazard ratios for risk of PAD per 1 mmol/L (39 mg/dL) increment in remnant and LDL cholesterol were 1.9 (95% CI, 1.5-2.4) and 1.1 (95% CI, 1.0-1.2), respectively; corresponding results in the UK Biobank were 1.7 (95% CI, 1.4-2.1) and 0.9 (95% CI, 0.9-1.0), respectively. In the association from elevated apoB to increased risk of PAD, remnant and LDL cholesterol explained 73% (32%-100%) and 8% (0%-46%), respectively; corresponding results were 63% (30%-100%) and 0% (0%-33%) for risk of chronic limb-threatening ischemia and 41% (27%-55%) and 54% (38%-70%) for risk of myocardial infarction; results for remnant and LDL particle counts corroborated these findings.

CONCLUSIONS

PAD risk conferred by elevated apoB-containing lipoproteins was explained mainly by elevated remnants, while myocardial infarction risk was explained by both elevated remnants and LDL.

Atherosclerosis Residual Lipid Risk-Overview of Existing and Future Pharmacotherapies

Patients with atherosclerotic disease remain at increased risk of future events despite receiving optimal medical treatment. This residual risk is widely heterogeneous, but lipoprotein particles and their content play a major role in determining future cardiovascular events. Beyond low-density lipoprotein cholesterol (LDL-c), other lipoprotein particles have not demonstrated similar contribution to the progression of atherosclerosis. Statins, ezetimibe, and more recently, proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors and bempedoic acid have confirmed the causal role of LDL-c in the development of atherosclerosis. Data on high-density lipoprotein cholesterol (HDL-c) suggested a possible causal role for atherosclerosis; nonetheless, HDL-c-raising treatments, including cholesteryl-ester transfer protein (CETP) inhibitors and niacin, failed to confirm this relationship. On the other hand, mendelian randomisation revealed that triglycerides are more implicated in the development of atherosclerosis. Although the use of highly purified eicosapentaenoic acid (EPA) was associated with a reduction in the risk of adverse cardiovascular events, this beneficial effect did not correlate with the reduction in triglycerides level and has not been consistent across large phase 3 trials. Moreover, other triglyceride-lowering treatments, such as fibrates, were not associated with a reduction in future cardiovascular risk. Studies assessing agents targeting angiopoietin-like 3 (lipoprotein lipase inhibitor) and apolipoprotein C3 antisense will add further insights into the role of triglycerides in atherosclerosis. Emerging lipid markers such as lipoprotein (a) and cholesterol efflux capacity may have a direct role in the progression of atherosclerosis. Targeting these biomarkers may provide incremental benefits in reducing cardiovascular risk when added to optimal medical treatment. This Review aims to assess available therapies for current lipid biomarkers and provide mechanistic insight into their potential role in reducing future cardiovascular risk.

Engineering Nanoplatforms for Theranostics of Atherosclerotic Plaques

Atherosclerotic plaque formation is considered the primary pathological mechanism underlying atherosclerotic cardiovascular diseases, leading to severe cardiovascular events such as stroke, acute coronary syndromes, and even sudden cardiac death. Early detection and timely intervention of plaques are challenging due to the lack of typical symptoms in the initial stages. Therefore, precise early detection and intervention play a crucial role in risk stratification of atherosclerotic plaques and achieving favorable post-interventional outcomes. The continuously advancing nanoplatforms have demonstrated numerous advantages including high signal-to-noise ratio, enhanced bioavailability, and specific targeting capabilities for imaging agents and therapeutic drugs, enabling effective visualization and management of atherosclerotic plaques. Motivated by these superior properties, various noninvasive imaging modalities for early recognition of plaques in the preliminary stage of atherosclerosis are comprehensively summarized. Additionally, several therapeutic strategies are proposed to enhance the efficacy of treating atherosclerotic plaques. Finally, existing challenges and promising prospects for accelerating clinical translation of nanoplatform-based molecular imaging and therapy for atherosclerotic plaques are discussed. In conclusion, this review provides an insightful perspective on the diagnosis and therapy of atherosclerotic plaques.

Current RNA strategies in treating cardiovascular diseases

Cardiovascular disease (CVD) continues to impose a significant global health burden, necessitating the exploration of innovative treatment strategies. Ribonucleic acid (RNA)-based therapeutics have emerged as a promising avenue to address the complex molecular mechanisms underlying CVD pathogenesis. We present a comprehensive review of the current state of RNA therapeutics in the context of CVD, focusing on the diverse modalities that bring about transient or permanent modifications by targeting the different stages of the molecular biology central dogma. Considering the immense potential of RNA therapeutics, we have identified common gene targets that could serve as potential interventions for prevalent Mendelian CVD caused by single gene mutations, as well as acquired CVDs developed over time due to various factors. These gene targets offer opportunities to develop RNA-based treatments tailored to specific genetic and molecular pathways, presenting a novel and precise approach to address the complex pathogenesis of both types of cardiovascular conditions. Additionally, we discuss the challenges and opportunities associated with delivery strategies to achieve targeted delivery of RNA therapeutics to the cardiovascular system. This review highlights the immense potential of RNA-based interventions as a novel and precise approach to combat CVD, paving the way for future advancements in cardiovascular therapeutics.

Discovery and Exploration of Lipid-Modifying Drug Targets for ALS by Mendelian Randomization

Observational studies have faced challenges in identifying replicable causes for amyotrophic lateral sclerosis (ALS). To address this, we employed an unbiased and data-driven approach to discover and explore potential causal exposures using two-sample Mendelian randomization (MR) analyses. In the phenotype discovery stage, we assessed 3948 environmental exposures from the UK Biobank and utilized ALS summary statistics (Europeans, 20,806 cases, 59,804 controls) as the outcome within a phenome-wide MR pipeline. Through a range of sensitivity analyses, two medication traits were identified to be protective for ALS. In the target exploration stage, we further conducted drug target MR analyses using the latest and trans-ethnic summary data on lipid-related traits and ALS (Europeans, 27,205 cases, 110,881 controls; East Asians, 1234 cases, 2850 controls). Our aim was to explore potential causal drug targets through six lipid-modifying effects. These comprehensive analyses revealed significant findings. Specifically, "cholesterol-lowering medication" and "atorvastatin" survived predefined criteria in the phenotype discovery stage and exhibited a protective effect on ALS. Further in the target exploration stage, we demonstrated that the therapeutic effect of APOB through LDL-lowering was associated with reduced ALS liability in Europeans (OR = 0.835, P = 5.61E - 5). Additionally, the therapeutic effect of APOA1 and LDLR through TC-lowering was associated with reduced ALS liability in East Asians (APOA1, OR = 0.859, P = 5.38E - 4; LDLR, OR = 0.910, P = 2.73E - 5). Overall, we propose potential protective effects of cholesterol-lowering drugs or statins on ALS risk from thousands of exposures. Our research also suggests APOB, APOA1, and LDLR as novel therapeutic targets for ALS and supports their potential protective mechanisms may be mediated by LDL-lowering or TC-lowering effects.

Patterns of Lipid Lowering Therapy Use Among Older Adults in a Managed Care Advantage Plan in the United States

Background: The prevalence of cardiovascular events is increasing. There are many new lipids lowering therapies available in recent years. Increased evidence through literature and guidelines suggests that the use of lipid lowering therapy (LLT) benefits patients who are at risk for cardiovascular events. Objective: The objective of this study was to describe the current LLT use as well as patterns of treatment modification among adults ≥ 65 years. Methods: A retrospective analysis of administrative claims data between January 2016 and May 2018 was conducted. Patients with a LLT refill and continuous enrollment during 1-year prior and 1-year follow-up were identified. The treatment episodes captured were interruption of therapy, intensity changes, dose changes, treatment augmentation, switching, and discontinuation. An analysis of treatment patterns among patients ≥75 years was also performed. Results: The study included 14,360 patients with a LLT of which 99% of patients were on statins as monotherapy or combination. Overall non-statin therapy use either as monotherapy or combination was 2.1%. There were significant differences among new initiators and existing users of therapy. Among prevalent users 57.4% had no changes in the follow-up period, 13.6% interrupted therapy, and 6.6% discontinued. Among new users, 47.9% patients had interrupted therapy, 25% had no changes, and 21.9% discontinued therapy. Conclusion: Most patients were on monotherapy and statins with low non-statin use. The new users among them were more likely to discontinue and interrupt therapy, highlighting the limitations and issues that older patients face that need to increase adherence.

A decreased level of high-density lipoprotein is a possible risk factor for type 2 diabetes mellitus: A review

Introduction

Type 2 diabetes mellitus (T2DM) is characterized primarily by dyslipidemia and hyperglycemia due to insulin resistance. High-density lipoprotein (HDL) play a significant role in preventing the incidence of dyslipidemia and its complications. HDL has different protective functions, such as reducing oxidation, vascular inflammation, and thrombosis; additionally, its anti-diabetic role is one of the most significant recent discoveries about HDL and some of its constituent lipoproteins.

Methods

This research reviews ongoing studies and preliminary investigations into the assessment of relation between decreased level of HDL and T2DM.

Results

The levels of HDL and its functions contribute to glucose hemostasis and the development of T2DM through four possible mechanisms, including insulin secretion by beta cells, peripheral insulin sensitivity, non-insulin-dependent glucose uptake, and adipose tissue metabolic activity. Additionally, the anti-oxidant properties of HDL protect beta cells from apoptosis caused by oxidative stress and inflammation induced by low-density lipoprotein, which facilitate insulin secretion.

Conclusion

Therefore, HDL and its compositions, especially Apo A-I, play an important role in regulating glucose metabolism, and decreased levels of HDL can be considered a risk factor for DM. Different factors, such as hypoalphalipoproteinemia that manifests as a consequence of genetic factors, such as Apo A-I deficiency, as well as secondary causes arising from lifestyle choices and underlying medical conditions that decrease the level of HDL, could be associated with DM. Moreover, intricate connections between HDL and diabetic complications extend beyond glucose metabolism to encompass complications like cardiovascular disease and kidney disease. Therefore, the exact interactions between HDL level and DM should be evaluated in future studies.

Contribution of intestinal triglyceride-rich lipoproteins to residual atherosclerotic cardiovascular disease risk in individuals with type 2 diabetes on statin therapy

AIMS/HYPOTHESIS

This study explored the hypothesis that significant abnormalities in the metabolism of intestinally derived lipoproteins are present in individuals with type 2 diabetes on statin therapy. These abnormalities may contribute to residual CVD risk.

METHODS

To investigate the kinetics of ApoB-48- and ApoB-100-containing lipoproteins, we performed a secondary analysis of 11 overweight/obese individuals with type 2 diabetes who were treated with lifestyle counselling and on a stable dose of metformin who were from an earlier clinical study, and compared these with 11 control participants frequency-matched for age, BMI and sex. Participants in both groups were on a similar statin regimen during the study. Stable isotope tracers were used to determine the kinetics of the following in response to a standard fat-rich meal: (1) apolipoprotein (Apo)B-48 in chylomicrons and VLDL; (2) ApoB-100 in VLDL, intermediate-density lipoprotein (IDL) and LDL; and (3) triglyceride (TG) in VLDL.

RESULTS

The fasting lipid profile did not differ significantly between the two groups. Compared with control participants, in individuals with type 2 diabetes, chylomicron TG and ApoB-48 levels exhibited an approximately twofold higher response to the fat-rich meal, and a twofold higher increment was observed in ApoB-48 particles in the VLDL1 and VLDL2 density ranges (all p < 0.05). Again comparing control participants with individuals with type 2 diabetes, in the latter, total ApoB-48 production was 25% higher (556 ± 57 vs 446 ± 57 mg/day; p < 0.001), conversion (fractional transfer rate) of chylomicrons to VLDL was around 40% lower (35 ± 25 vs 82 ± 58 pools/day; p=0.034) and direct clearance of chylomicrons was 5.6-fold higher (5.6 ± 2.2 vs 1.0 ± 1.8 pools/day; p < 0.001). During the postprandial period, ApoB-48 particles accounted for a higher proportion of total VLDL in individuals with type 2 diabetes (44%) compared with control participants (25%), and these ApoB-48 VLDL particles exhibited a fivefold longer residence time in the circulation (p < 0.01). No between-group differences were seen in the kinetics of ApoB-100 and TG in VLDL, or in LDL ApoB-100 production, pool size and clearance rate. As compared with control participants, the IDL ApoB-100 pool in individuals with type 2 diabetes was higher due to increased conversion from VLDL2.

CONCLUSIONS/INTERPRETATION

Abnormalities in the metabolism of intestinally derived ApoB-48-containing lipoproteins in individuals with type 2 diabetes on statins may help to explain the residual risk of CVD and may be suitable targets for interventions.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02948777.

Modelling the potential long-term survival benefit of evinacumab treatment vs. standard of care in patients with homozygous familial hypercholesterolaemia

AIMS

Despite intensive lipid-lowering therapies (LLTs), most patients with homozygous familial hypercholesterolaemia (HoFH) do not achieve guideline recommended low-density lipoprotein cholesterol (LDL-C) targets and are at increased risk of premature cardiovascular death. This analysis aimed to predict the impact of evinacumab and standard-of-care LLTs on life expectancy in an HoFH population using mathematical modelling.

METHODS AND RESULTS

Mathematical models were developed using efficacy data for evinacumab from the phase 3 ELIPSE HoFH trial plus efficacy data for standard-of-care LLTs from peer-reviewed publications. Treatment strategies evaluated included (i) untreated, (ii) high-intensity statin (HIS) only, (iii) HIS plus ezetimibe, (iv) HIS plus ezetimibe plus proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i), and (v) HIS plus ezetimibe plus PCSK9i plus evinacumab. Markov analyses were used to assess differences in survival probability for different LLT strategies. The median survival for untreated HoFH patients was only 33-43 years, depending on different assumptions on baseline untreated LDL-C levels. In the most robust model, we estimated that HIS increased median survival by 9 years and ezetimibe further increased median survival by an additional 9 years. When PCSK9i was added on top of HIS plus ezetimibe, median survival was further improved by 14 years. Finally, the addition of evinacumab to standard-of-care LLTs was estimated to increase median survival by ∼12 years.

CONCLUSION

In this mathematical modelling analysis, evinacumab treatment could potentially increase long-term survival vs. standard-of-care LLTs for patients with HoFH.

Drug Therapy for Hypertriglyceridemia and Familial Chylomicronemia Syndrome: Focus on Volnesorsen

Volanesorsen is a new medication that may soon be used in the treatment of hypertriglyceridemia and familial chylomicronemia syndrome (FCS). Volanesorsen works via binding to Apo C-III mRNA and degrading that mRNA, thus decreasing the synthesis of Apo C-III. This decreased synthesis of Apo C-III will increase the binding of triglycerides to LDL receptors and decrease triglyceride plasma levels. It is important to note that currently there are 3 other medication classes available for the treatment of hypertriglyceridemia, including niacin, fish oil/omega-3-fatty acids, and fibrates. However, there are no Food and Drug Administration-approved medications to treat FCS. Recently, volanesorsen was approved in the European Union for the treatment of FCS, but that indication was denied in the United States by the Food and Drug Administration. This was due to the side effects of the drug. Volanesorsen may cause a decrease in platelet count, renal toxicity, and elevate liver enzymes. The current drug regimen for volanesorsen consists of 285 mg once a week by subcutaneous injection, with a recommendation to immediately stop the medication if any of these side effects are noted, to prevent long-term complications. With these side effects reported, fish oil/omega-3-fatty acids seem likely the best choice when it comes to treating hypertriglyceridemia. If FCS is debilitating or greatly affecting the patient's life, then one could recommend volanesorsen. Otherwise, at this time, the side effects of volanesorsen may be too severe to justify its use for mild episodes of FCS or hypertriglyceridemia.

Intracellular spatiotemporal metabolism in connection to target engagement

The metabolism in eukaryotic cells is a highly ordered system involving various cellular compartments, which fluctuates based on physiological rhythms. Organelles, as the smallest independent sub-cell unit, are important contributors to cell metabolism and drug metabolism, collectively designated intracellular metabolism. However, disruption of intracellular spatiotemporal metabolism can lead to disease development and progression, as well as drug treatment interference. In this review, we systematically discuss spatiotemporal metabolism in cells and cell subpopulations. In particular, we focused on metabolism compartmentalization and physiological rhythms, including the variation and regulation of metabolic enzymes, metabolic pathways, and metabolites. Additionally, the intricate relationship among intracellular spatiotemporal metabolism, metabolism-related diseases, and drug therapy/toxicity has been discussed. Finally, approaches and strategies for intracellular spatiotemporal metabolism analysis and potential target identification are introduced, along with examples of potential new drug design based on this.

Low cholesterol states: clinical implications and management

INTRODUCTION

Hypocholesterolemia results from genetic - both monogenic and polygenic - and non-genetic causes and can sometimes be a source of clinical concern. We review etiologies and sequelae of hypocholesterolemia and therapeutics inspired from genetic hypocholesterolemia.

AREAS COVERED

Monogenic hypocholesterolemia disorders caused by the complete absence of apolipoprotein (apo) B-containing lipoproteins (abetalipoproteinemia and homozygous hypobetalipoproteinemia) or an isolated absence of apo B-48 lipoproteinemia (chylomicron retention disease) lead to clinical sequelae. These include gastrointestinal disturbances and severe vitamin deficiencies that affect multiple body systems, i.e. neurological, musculoskeletal, ophthalmological, and hematological. Monogenic hypocholesterolemia disorders with reduced but not absent levels of apo B lipoproteins have a milder clinical presentation and patients are protected against atherosclerotic cardiovascular disease. Patients with heterozygous hypobetalipoproteinemia have somewhat increased risk of hepatic disease, while patients with PCSK9 deficiency, ANGPTL3 deficiency, and polygenic hypocholesterolemia typically have anunremarkable clinical presentation.

EXPERT OPINION

In patients with severe monogenic hypocholesterolemia, early initiation of high-dose vitamin therapy and a low-fat diet are essential for optimal prognosis. The molecular basis of monogenic hypocholesterolemia has inspired novel therapeutics to help patients with the opposite phenotype - i.e. elevated apo B-containing lipoproteins. In particular, inhibitors of PCSK9 and ANGPTL3 show important clinical impact.

Intravascular imaging assessment of pharmacotherapies targeting atherosclerosis: advantages and limitations in predicting their prognostic implications

Intravascular imaging has been often used over the recent years to examine the efficacy of emerging therapies targeting plaque evolution. Serial intravascular ultrasound, optical coherence tomography, or near-infrared spectroscopy-intravascular ultrasound studies have allowed us to evaluate the effects of different therapies on plaque burden and morphology, providing unique mechanistic insights about the mode of action of these treatments. Plaque burden reduction, a decrease in necrotic core component or macrophage accumulation-which has been associated with inflammation-and an increase in fibrous cap thickness over fibroatheromas have been used as surrogate endpoints to assess the value of several drugs in inhibiting plaque evolution and improving clinical outcomes. However, some reports have demonstrated weak associations between the effects of novel treatments on coronary atheroma and composition and their prognostic implications. This review examines the value of invasive imaging in assessing pharmacotherapies targeting atherosclerosis. It summarizes the findings of serial intravascular imaging studies assessing the effects of different drugs on atheroma burden and morphology and compares them with the results of large-scale trials evaluating their impact on clinical outcome. Furthermore, it highlights the limited efficacy of established intravascular imaging surrogate endpoints in predicting the prognostic value of these pharmacotherapies and introduces alternative imaging endpoints based on multimodality/hybrid intravascular imaging that may enable more accurate assessment of the athero-protective and prognostic effects of emerging therapies.

Posing the rationale for synthetic lipoxin mimetics as an adjuvant treatment to gold standard atherosclerosis therapies

Atherosclerosis is a progressive, multifactorial inflammatory, and dyslipidaemic disease, responsible for the majority of cardiovascular diseases globally. The chronic inflammation is the main driver of the initiation and progression of such disease, as a result of an imbalanced lipid metabolism and an ineffective immune response to attenuate the inflammatory component. The importance of inflammation resolution is being increasingly recognised in atherosclerosis and cardiovascular disease. It has a complex mechanism consisting of multiple stages, including restoring an effective removal of apoptotic bodies (efferocytosis) and their degradation (effero-metabolism), a macrophage phenotype switching towards resolving phenotypes, and the promotion of tissue healing and regeneration. The low-grade inflammation associated with atherosclerosis development is a driving force in disease exacerbation, and hence inflammation resolution is a key area of research. In this review, we explore the complex disease pathogenesis and its many contributing factors to gain a greater understanding of the disease and identify the current and potential therapeutic targets. First-line treatments and their efficacy will also be discussed in detail, to highlight the emerging field of resolution pharmacology. Despite the great efforts made by current gold-standard treatments, such as lipid-lowering and glucose-lowering drugs, they remain ineffective at tackling residual inflammatory risk and residual cholesterol risk. Resolution pharmacology represents a new era of atherosclerosis therapy, as endogenous ligands associated with inflammation resolution are exploited for their pharmacological benefits in a more potent and longer-acting manner. Novel FPR2-agonists, such as synthetic lipoxin analogues, provide an exciting new approach to enhance the pro-resolving response of the immune system and subsequently end the pro-inflammatory response to allow for an anti-inflammatory and pro-resolving environment for tissue healing, regeneration, and return to homeostasis.

The Pathogenetic Basis of the Action of Bempedoic Acid

The modern cardiology has a wide range of medications which affect various pathogenetic links of atherosclerosis, but even the best of them still obtain disadvantages causing intolerance and medicine discontinuation. The development of new hypolipidemic medications will allow not only to introduce alternative therapies into the cardiology practice, but also to completely execute the strategy of residual risk reduction by utilizing rational combinations of medications. One of such alternatives could be bempedoic acid, which can have a positive effect on a number of endpoints as the results of third phase trials have shown. These effects are also confirmed in Mendelian randomization studies. The mechanism of action of bempedoic acid is presumably associated with inhibition of the activity of ATP citrate lyase – the enzyme responsible for the breakdown of citrate into acetyl-CoA and oxaloacetate. Acetyl-CoA, in turn, is used by the cell to synthesize cholesterol and fatty acids. Thus, bempedoic acid affects in the same metabolic pathway as statins, but at an earlier stage. According to this, it is possible that medications of these classes will have similar side effects and pleiotropic effects associated with modulation of the mevalonic pathway, such as prenylation regulatory proteins (small GTPases) or reduction of coenzyme Q synthesis. However, there are also some specific features of the pharmacodynamics and pharmacokinetics of bempedoic acid to be considered. In particular, once entered the body, it must be activated via esterification by very long-chain acyl-CoA synthetase-1. The enzyme isoform required for this process is expressed in a tissue-specific manner and, for example, is absent in skeletal myocytes. In addition, citrate, oxaloacetate, and acetyl-CoA are important regulators of many intracellular processes: metabolism, growth and proliferation, mechanotransduction, posttranslational modifications of histones and other proteins. The levels of all three substances are altered by bempedoic acid, although no firm conclusions about the effects of these changes can be drawn at this time. The mentioned features probably have a significant impact on the clinical profile of bempedoic acid and underlie the differences from statins already observed in third phase trials, including, for example, a reduced risk of the onset or worsening of diabetes mellitus while taking bempedoic acid.

Management of Familial Hypercholesterolemia with Special Emphasis on Evinacumab

Familial hypercholesterolemia (FH) is an underdiagnosed disease that contributes to a significant number of cardiovascular incidents through high serum Low-Density Lipoprotein Cholesterol (LDL-C) values. Its treatment primarily requires healthy lifestyle and therapy based on statins, ezetimibe and Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9); however, there are also new treatment options that can be used in patients who do not respond to therapy, among which we highlight evinacumab. Elevated LDL-C values, together with clinical manifestations associated with cholesterol deposition (e.g., tendon xanthomas, xanthelasma and arcus cornealis) and family history are the main elements in the diagnosis of FH. Pathognomonic signs of FH include extensor tendon xanthomas; however, their absence does not exclude the diagnosis. Elevated LDL-C levels lead to premature Atherosclerotic Cardiovascular Disease (ASCVD), which is why early diagnosis and treatment of FH is essential. Evinacumab, a novelty in pharmacological practice, having a complex mechanism of action, causes desirable changes in lipid parameters in patients with homozygous form of familial hypercholesterolemia (HoFH). This review collects and summarizes the most important aspects of the new drug, especially being a discovery in the treatment of HoFH, giving these patients hope for a longer and more comfortable life.

Novel pathogenic variant combination in LPL causing familial chylomicronemia syndrome in an Asian family and experimental validation in vitro: a case report

BACKGROUND

Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive disorder, typically caused by biallelic pathogenic variants in the lipoprotein lipase (LPL) gene. Lipoprotein lipase, encoded by the LPL gene, catalyzes the hydrolysis of triglycerides, and its deficiency or dysfunction can lead to chylomicronemia and potentially fatal recurrent acute pancreatitis.

CASE DESCRIPTION

Here, we report an Asian child with FCS due to compound heterozygous LPL variants. The 4-year-old patient presented with splenomegaly and severe hypertriglyceridemia, specifically chylomicronemia which resulted in abnormal coagulation measured by a turbidity-based assay. Based on the clinical features and family history, the diagnosis of FCS was suspected, and confirmed by the identification of compound heterozygous variants in the LPL gene (c.461A>G; p.His154Arg and c.788T>A; p.Leu263Gln) in the patient, inheriting one from each parent. According to the clinical and genetic findings, the patient was diagnosed with FCS. In vitro experimental validation found that the LPL p.H154R variant reduced the expression of lipoprotein lipase and decreased its lipolytic activity, while the LPL p.L263Q variant mainly impaired its lipolytic activity.

CONCLUSIONS

FCS was molecularly diagnosed using whole exome sequencing in the case presented. When interpreting abnormal coagulation profiles measured by turbidity-based assay, the possibility of lipemic blood (or chylomicronemia) should be considered and the presence of this phenomenon might indicate the diagnosis of FCS. In vitro experiments showed that the two LPL variants impaired lipoprotein lipase expression and/or function making them likely to be pathogenic.

Curcumin nicotinate decreases serum LDL cholesterol through LDL receptor-mediated mechanism

Curcumin nicotinate (Curtn) is a synthesized ester derivative of curcumin and niacin. Our previous study has shown that Curtn lowers serum low-density lipoprotein cholesterol (LDL-C) levels in apoE^-/- mice and promotes LDL-C uptake into HepG2 cells in vitro. The present study was to test the hypothesis that Curtn decreases serum LDL-C levels through decreased expression of pro-protein convertase subtilisin/kexin type 9 (PCSK9) and subsequent increase in LDL receptor expression. Male Wistar rats on high-fat diet (HFD) were treated with Curtn or rosuvastatin. Curtn or rosuvastatin treatment significantly decreased serum levels of total cholesterol (TC) and LDL-C in rats on HFD with increased liver LDL receptor expression. LDL-C-lowering effect of Curtn was not observed in LDL receptor deficient (LDLR^-/-) mice on HFD, while rosuvastatin still decreased serum lipid levels in LDLR^-/- mice, indicating that the reduction of serum LDL-C levels by Curtn treatment was LDL receptor-dependent. Curtn treatment also significantly decreased the protein expression of PCSK9 in Wistar rats and LDLR^-/- mice. In HepG2 cells with overexpression of human PCSK9, Curtn treatment significantly increased LDL-C uptakes into hepatocytes, and increased LDL receptor distribution on cell surface in association with decreased PCSK9 protein expression. RNAi-LDLR significantly attenuated the effect of Curtn on LDLR distribution on cell surface. These data indicates that Curtn would decrease serum LDL-C level at least partially through inhibition of PCSK9 expression, and subsequent increase in LDL receptor expression and distribution in hepatocytes, serving as a potential novel compound to treat hyperlipidemia.

Regulation of cholesterol homeostasis in health and diseases: from mechanisms to targeted therapeutics

Disturbed cholesterol homeostasis plays critical roles in the development of multiple diseases, such as cardiovascular diseases (CVD), neurodegenerative diseases and cancers, particularly the CVD in which the accumulation of lipids (mainly the cholesteryl esters) within macrophage/foam cells underneath the endothelial layer drives the formation of atherosclerotic lesions eventually. More and more studies have shown that lowering cholesterol level, especially low-density lipoprotein cholesterol level, protects cardiovascular system and prevents cardiovascular events effectively. Maintaining cholesterol homeostasis is determined by cholesterol biosynthesis, uptake, efflux, transport, storage, utilization, and/or excretion. All the processes should be precisely controlled by the multiple regulatory pathways. Based on the regulation of cholesterol homeostasis, many interventions have been developed to lower cholesterol by inhibiting cholesterol biosynthesis and uptake or enhancing cholesterol utilization and excretion. Herein, we summarize the historical review and research events, the current understandings of the molecular pathways playing key roles in regulating cholesterol homeostasis, and the cholesterol-lowering interventions in clinics or in preclinical studies as well as new cholesterol-lowering targets and their clinical advances. More importantly, we review and discuss the benefits of those interventions for the treatment of multiple diseases including atherosclerotic cardiovascular diseases, obesity, diabetes, nonalcoholic fatty liver disease, cancer, neurodegenerative diseases, osteoporosis and virus infection.

An Ultrasound-Responsive Theranostic Cyclodextrin-Loaded Nanoparticle for Multimodal Imaging and Therapy for Atherosclerosis

Atherosclerosis is a major cause of mortality and morbidity worldwide. Left undiagnosed and untreated, atherosclerotic plaques can rupture and cause cardiovascular complications such as myocardial infarction and stroke. Atherosclerotic plaques are composed of lipids, including oxidized low-density lipoproteins and cholesterol crystals, and immune cells, including macrophages. 2-Hydroxypropyl-beta-cyclodextrin (CD) is FDA-approved for capturing, solubilizing, and delivering lipophilic drugs in humans. It is also known to dissolve cholesterol crystals and decrease atherosclerotic plaque size. However, its low retention time necessitates high dosages for successful therapy. This study reports CD delivery via air-trapped polybutylcyanoacrylate nanoparticles (with diameters of 388 ± 34 nm) loaded with CD (CDNPs). The multimodal contrast ability of these nanoparticles after being loaded with IR780 dye in mice is demonstrated using ultrasound and near-infrared imaging. It is shown that CDNPs enhance the cellular uptake of CD in murine cells. In an ApoE^-/- mouse model of atherosclerosis, treatment with CDNPs significantly improves the anti-atherosclerotic efficacy of CD. Ultrasound triggering further improves CD uptake, highlighting that CDNPs can be used for ultrasound imaging and ultrasound-responsive CD delivery. Thus, CDNPs represent a theranostic nanocarrier for potential application in patients with atherosclerosis.

A Modern Approach to Dyslipidemia

Lipid disorders involving derangements in serum cholesterol, triglycerides, or both are commonly encountered in clinical practice and often have implications for cardiovascular risk and overall health. Recent advances in knowledge, recommendations, and treatment options have necessitated an updated approach to these disorders. Older classification schemes have outlived their usefulness, yielding to an approach based on the primary lipid disturbance identified on a routine lipid panel as a practical starting point. Although monogenic dyslipidemias exist and are important to identify, most individuals with lipid disorders have polygenic predisposition, often in the context of secondary factors such as obesity and type 2 diabetes. With regard to cardiovascular disease, elevated low-density lipoprotein cholesterol is essentially causal, and clinical practice guidelines worldwide have recommended treatment thresholds and targets for this variable. Furthermore, recent studies have established elevated triglycerides as a cardiovascular risk factor, whereas depressed high-density lipoprotein cholesterol now appears less contributory than was previously believed. An updated approach to diagnosis and risk assessment may include measurement of secondary lipid variables such as apolipoprotein B and lipoprotein(a), together with selective use of genetic testing to diagnose rare monogenic dyslipidemias such as familial hypercholesterolemia or familial chylomicronemia syndrome. The ongoing development of new agents-especially antisense RNA and monoclonal antibodies-targeting dyslipidemias will provide additional management options, which in turn motivates discussion on how best to incorporate them into current treatment algorithms.

New Therapeutic Approaches in Treatment of Dyslipidaemia—A Narrative Review

Dyslipidaemia is a well-known risk factor for the development of cardiovascular disease, a leading cause of morbidity and mortality in developed countries. As a consequence, the medical community has been dealing with this problem for decades, and traditional statin therapy remains the cornerstone therapeutic approach. However, clinical trials have observed remarkable results for a few agents effective in the treatment of elevated serum lipid levels. Ezetimibe showed good but limited results when used in combination with statins. Bempedoic acid has been thoroughly studied in multiple clinical trials, with a reduction in LDL cholesterol by approximately 15%. The first approved monoclonal antibodies for the treatment of dyslipidaemia, PCSK9 inhibitors, are currently used as second-line treatment for patients with unregulated lipid levels on statin or statin combination therapy. A new siRNA molecule, inclisiran, demonstrates great potential, particularly concerning compliance, as it is administered twice yearly and pelacarsen, an antisense oligonucleotide that targets lipoprotein(a) and lowers its levels. Volanesorsen is the first drug that was designed to target chylomicrons and lower triglyceride levels, and olezarsen, the next in-line chylomicron lowering agent, is currently being researched. The newest possibilities for the treatment of dyslipidaemia are ANGPTL3 inhibitors with evinacumab, already approved by the FDA, and EMA for the treatment of familial hypercholesterolemia. This article provides a short summary of new agents currently used or being developed for lipid lowering treatment.

Deep Lipidomics in Human Plasma: Cardiometabolic Disease Risk and Effect of Dietary Fat Modulation

BACKGROUND

In blood and tissues, dietary and endogenously generated fatty acids (FAs) occur in free form or as part of complex lipid molecules that collectively represent the lipidome of the respective tissue. We assessed associations of plasma lipids derived from high-resolution lipidomics with incident cardiometabolic diseases and subsequently tested if the identified risk-associated lipids were sensitive to dietary fat modification.

METHODS

The EPIC Potsdam cohort study (European Prospective Investigation into Cancer and Nutrition) comprises 27 548 participants recruited within an age range of 35 to 65 years from the general population around Potsdam, Germany. We generated 2 disease-specific case cohorts on the basis of a fixed random subsample (n=1262) and all respective cohort-wide identified incident primary cardiovascular disease (composite of fatal and nonfatal myocardial infarction and stroke; n=551) and type 2 diabetes (n=775) cases. We estimated the associations of baseline plasma concentrations of 282 class-specific FA abundances (calculated from 940 distinct molecular species across 15 lipid classes) with the outcomes in multivariable-adjusted Cox models. We tested the effect of an isoenergetic dietary fat modification on risk-associated lipids in the DIVAS randomized controlled trial (Dietary Intervention and Vascular Function; n=113). Participants consumed either a diet rich in saturated FAs (control), monounsaturated FAs, or a mixture of monounsaturated and n-6 polyunsaturated FAs for 16 weeks.

RESULTS

Sixty-nine lipids associated (false discovery rate<0.05) with at least 1 outcome (both, 8; only cardiovascular disease, 49; only type 2 diabetes, 12). In brief, several monoacylglycerols and FA16:0 and FA18:0 in diacylglycerols were associated with both outcomes; cholesteryl esters, free fatty acids, and sphingolipids were largely cardiovascular disease specific; and several (glycero)phospholipids were type 2 diabetes specific. In addition, 19 risk-associated lipids were affected (false discovery rate<0.05) by the diets rich in unsaturated dietary FAs compared with the saturated fat diet (17 in a direction consistent with a potential beneficial effect on long-term cardiometabolic risk). For example, the monounsaturated FA-rich diet decreased diacylglycerol(FA16:0) by 0.4 (95% CI, 0.5-0.3) SD units and increased triacylglycerol(FA22:1) by 0.5 (95% CI, 0.4-0.7) SD units.

CONCLUSIONS

We identified several lipids associated with cardiometabolic disease risk. A subset was beneficially altered by a dietary fat intervention that supports the substitution of dietary saturated FAs with unsaturated FAs as a potential tool for primary disease prevention.

RNA interference-based therapies for the control of atherosclerosis risk factors

PURPOSE OF REVIEW

Atherosclerosis, characterized by lipid accumulation and chronic inflammation in the arterial wall, is the leading causes of death worldwide. The purpose of this article is to review the status of RNA interference (RNAi) based therapies in clinical trials for the treatment and prevention of atherosclerosis risk factors.

RECENT FINDINGS

There is a growing interest on using RNAi technology for the control of atherosclerosis risk factors. Current clinical trials utilizing RNAi for atherosclerosis are targeting lipid metabolism regulating genes including proprotein convertase subtilisin/kexin 9, apolipoprotein C-III, lipoprotein (a) and angiopoietin-like protein 3. Currently, three RNAi-based drugs have been approved by U.S. Food and Drug Administration, but there are several therapies in clinical trials at the moment, and potentially entering the market in near future. In addition, recent preclinical studies on regulating vascular inflammation have shown promising results.

SUMMARY

In recent years, RNAi based technologies and therapies have been intensively developed for the treatment of atherosclerosis risk factors, such as hyperlipidemia and vascular inflammation. Multiple potential therapeutic targets have emerged, and many of the reported clinical trials have already been successful in plasma lipid lowering. The scope of RNAi therapies is well recognized and recent approvals are encouraging for the treatment of cardiovascular and metabolic disorders.

A mathematical model of in vitro hepatocellular cholesterol and lipoprotein metabolism for hyperlipidemia therapy

Cardiovascular diseases associated with high cholesterol (hypercholesterolemia) and low-density lipoproteins (LDL) levels are significant contributors to total mortality in developing and developed countries. Mathematical modeling of LDL metabolism is an important step in the development of drugs for hypercholesterolemia. The aim of this work was to develop and to analyze an integrated mathematical model of cholesterol metabolism in liver cells and its interaction with two types of drugs, statins and PCSK9 inhibitors. The model consisted of 21 ordinary differential equations (ODE) describing cholesterol biosynthesis and lipoprotein endocytosis in liver cells in vitro. The model was tested for its ability to mimic known biochemical effects of familial hypercholesterolemia, statin therapy, and PCSK9 inhibitors. The model qualitatively reproduced the well-known biology of cholesterol regulation, which confirms its potential for minimizing cellular research in initial testing of new drugs for cardiology.

Regulatory Effects of Statins on SIRT1 and Other Sirtuins in Cardiovascular Diseases

Adverse cardiovascular disease (CVD) outcomes, such as sudden cardiac death, acute myocardial infarction, and stroke, are often catastrophic. Statins are frequently used to attenuate the risk of CVD-associated morbidity and mortality through their impact on lipids and they may also have anti-inflammatory and other plaque-stabilization effects via different signaling pathways. Different statins, including atorvastatin, rosuvastatin, pravastatin, pitavastatin, and simvastatin, are administered to manage circulatory lipid levels. In addition, statins are potent inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase via modulating sirtuins (SIRTs). During the last two decades, SIRTs have been investigated in mammals and categorized as a family of nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylases (HDACs) with significant oxidative stress regulatory function in cells—a key factor in extending cell lifespan. Recent work has demonstrated that statins upregulate SIRT1 and SIRT2 and downregulate SIRT6 in both in vitro and in vivo experiments and clinical trials. As statins show modulatory properties, especially in CVDs, future investigations are needed to delineate the role of SIRT family members in disease and to expand knowledge about the effects of statins on SIRTs. Here, we review what is currently known about the impact of statins on SIRTs and how these changes correlate with disease, particularly CVDs.

Lipid-Modifying Therapies and Stroke Prevention

PURPOSE OF REVIEW

We reviewed lipid-modifying therapies and the risk of stroke and other cerebrovascular outcomes, with a focus on newer therapies.

RECENT FINDINGS

Statins and ezetimibe reduce ischemic stroke risk without increasing hemorrhagic stroke risk. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors similarly reduce ischemic stroke risk in statin-treated patients with atherosclerosis without increasing hemorrhagic stroke, even with very low achieved low-density lipoprotein cholesterol levels. Icosapent ethyl reduces the risk of total and first ischemic stroke in patients with established cardiovascular disease or diabetes mellitus. Clinical outcome trials are underway for newer lipid-modifying agents, including inclisiran, bempedoic acid, and pemafibrate. New biologic agents including evinacumab, pelacarsen, olpasiran, and SLN360 are also discussed. In addition to statins and ezetimibe, PCSK9 inhibitors and icosapent ethyl reduce the risk of ischemic stroke without increasing the risk of hemorrhagic stroke. These therapies dramatically expand options for reducing stroke in high-risk settings.

High-Intensity Statin Use Among Patients With Atherosclerosis in the U.S

BACKGROUND

Preventive therapy among patients with established atherosclerotic cardiovascular disease (ASCVD) is generally underused. Whether new guideline recommendations and a focus on implementation have improved the use of high-intensity statins is unknown.

OBJECTIVES

This study sought to evaluate the patterns and predictors of statin use among patients with ASCVD.

METHODS

In this retrospective cohort study, pharmacy and medical claims data from a commercial health plan were queried for patients with established ASCVD between January 31, 2018, and January 31, 2019. Statin use on an index date of January 31, 2019, was evaluated, as was 12-month adherence and discontinuation. Multivariable logistic regression was used to determine independent associations with statin use of varying intensities.

RESULTS

Of the 601,934 patients with established ASCVD, 41.7% were female, and the mean age was 67.5 ± 13.3 years. Overall, 22.5% of the cohort were on a high-intensity statin, 27.6% were on a low- or moderate-intensity statin, and 49.9% were not on any statin. In multivariable analysis, younger patients, female patients, and those with higher Charlson comorbidity score were less likely to be prescribed any statin. Among statin users, female patients, older patients, and those with peripheral artery disease were less likely to be on a high-intensity formulation, whereas a cardiology encounter in the prior year increased the odds. The majority of high-intensity stain users achieved high levels of adherence.

CONCLUSIONS

Substantial underuse of statins persists in a large, insured, and contemporary cohort of patients with ASCVD from the United States. In particular, concerning gaps in appropriate statin use remain among younger patients, women, and those with noncoronary ASCVD.

Effect of Vupanorsen on Non-High-Density Lipoprotein Cholesterol Levels in Statin-Treated Patients With Elevated Cholesterol: TRANSLATE-TIMI 70

Genetic loss-of-function variants in ANGPTL3 are associated with lower levels of plasma lipids. Vupanorsen is a hepatically targeted antisense oligonucleotide that inhibits Angiopoietin-like 3 (ANGPTL3) protein synthesis.

Acute coronary syndromes

Although substantial progress has been made in the diagnosis and treatment of acute coronary syndromes, cardiovascular disease remains the leading cause of death globally, with nearly half of these deaths due to ischaemic heart disease. The broadening availability of high-sensitivity troponin assays has allowed for rapid rule-out algorithms in patients with suspected non-ST-segment elevated myocardial infarction (NSTEMI). Dual antiplatelet therapy is recommended for 12 months following an acute coronary syndrome in most patients, and additional secondary prevention measures including intensive lipid-lowering therapy (LDL-C <1·4 mmol/L), neurohormonal agents, and lifestyle modification, are crucial. The scientific evidence for diagnosis and management of acute coronary syndromes continues to evolve rapidly, including adapting to the COVID-19 pandemic, which has impacted all aspects of care. This Seminar provides a clinically relevant overview of the pathobiology, diagnosis, and management of acute coronary syndromes, and describes key scientific advances.

The dawn of a new era of targeted lipid-lowering therapies

Lipid risk factors for cardiovascular disease depend in part on lifestyle, but optimum control of lipids often demands additional measures. Low-density lipoprotein (LDL) doubtless contributes causally to atherosclerosis. Recent human genetic findings have substantiated a number of novel targets for lipid-lowering therapy including apolipoprotein C-III, angiopoietin-like protein 3 and 4, apolipoprotein V, and ATP citrate lyase. These discoveries coupled with advances in biotechnology development afford new avenues for management of LDL and other aspects of lipid risk. Beyond LDL, new treatments targeting triglyceride-rich lipoproteins and lipoprotein(a) have become available and have entered clinical development. Biological and RNA-directed agents have joined traditional small-molecule approaches, which themselves have undergone considerable refinement. Innovative targeting strategies have increased efficacy of some of these novel interventions and markedly improved their tolerability. Gene-editing approaches have appeared on the horizon of lipid management. This article reviews this progress offering insight into novel biological and therapeutic discoveries, and places them into a practical patient care perspective.

An evaluation of the pharmacokinetics of inclisiran in the treatment of atherosclerotic cardiovascular disease

INTRODUCTION

Inclisiran is a small interfering RNA that inhibits hepatic production of proprotein convertase subtilisin/kexin type 9 (PCSK9) which results in reduction of circulating low-density lipoprotein cholesterol (LDL-C). It can be used alone or in combination with statins or other lipid-lowering therapy.

AREAS COVERED

In this article we review the pharmacokinetics, pharmacodynamics and clinical efficacy of inclisiran based on the published literature.

EXPERT OPINION

Inclisiran is a chemically stabilized duplex RNA conjugated with triantennary N-acetylgalactosamine which facilitates rapid and selective liver uptake and the drug is almost entirely removed from the circulation within 24 hours after subcutaneous injection. The duration of action is impressively prolonged and after doses of 300 mg on days one and 90, the dose can be repeated every six months to maintain a durable reduction of LDL-C by about 50%. The efficacy and safety are similar to the monoclonal antibodies targeting PCSK9, evolocumab and alirocumab, and injection site reactions are infrequent and generally mild. The cardiovascular outcome study with inclisiran is ongoing and other long term safety data are keenly awaited. The infrequent dosing regimen offers a major advantage to improve long term compliance and inclisiran may be extensively adopted depending on the cost.

Non-stenotic Carotid Plaques in Embolic Stroke of Unknown Source

Embolic stroke of unknown source (ESUS) represents one in five ischemic strokes. Ipsilateral non-stenotic carotid plaques are identified in 40% of all ESUS. In this narrative review, we summarize the evidence supporting the potential causal relationship between ESUS and non-stenotic carotid plaques; discuss the remaining challenges in establishing the causal link between non-stenotic plaques and ESUS and describe biomarkers of potential interest for future research. In support of the causal relationship between ESUS and non-stenotic carotid plaques, studies have shown that plaques with high-risk features are five times more prevalent in the ipsilateral vs. the contralateral carotid and there is a lower incidence of atrial fibrillation during follow-up in patients with ipsilateral non-stenotic carotid plaques. However, non-stenotic carotid plaques with or without high-risk features often coexist with other potential etiologies of stroke, notably atrial fibrillation (8.5%), intracranial atherosclerosis (8.4%), patent foramen ovale (5-9%), and atrial cardiopathy (2.4%). Such puzzling clinical associations make it challenging to confirm the causal link between non-stenotic plaques and ESUS. There are several ongoing studies exploring whether select protein and RNA biomarkers of plaque progression or vulnerability could facilitate the reclassification of some ESUS as large vessel strokes or help to optimize secondary prevention strategies.

Volanesorsen for treatment of familial chylomicronemia syndrome

INTRODUCTION

Familial chylomicronemia syndrome (FCS) is a rare subtype of severe hypertriglyceridemia that affects ~1 in 100, 000 to 1,000,000 individuals. The major risk to health is acute pancreatitis. FCS is defined by biallelic loss-of-function mutations in one of five canonical genes that encode proteins critical to lipolysis of large triglyceride-rich lipoprotein particles. Unlike the vast majority of patients with severe hypertriglyceridemia, FCS patients lack any lipolytic capacity and are thus resistant to standard medications.

AREAS COVERED

This review focuses on a mechanism that effectively reduces elevated triglyceride levels in FCS, namely interference of synthesis of apolipoprotein (apo) C-III. Volanesorsen is an antisense RNA drug administered subcutaneously that knocks down apo C-III, resulting in dramatic reductions in triglyceride levels both in FCS patients and in the wider population of subjects with severe hypertriglyceridemia.

EXPERT OPINION

Volanesorsen is a highly effective treatment to reduce elevated triglycerides in FCS patients, providing proof-of-concept of the validity of targeting apo C-III. However, off target effects of volanesorsen, including thrombocytopenia, may ultimately limit its use. Nonetheless, building on the knowledge derived from the volanesorsen experience, there is intensified interest in promising newer agents that also target apo C-III but have technical modifications that limit potential off target adverse effects.

The Role of Antisense Therapies Targeting Lipoprotein(a)

ABSTRACT

Atherosclerotic cardiovascular disease (ASCVD) continues to be the leading cause of preventable death in the United States. Elevated low-density lipoprotein cholesterol (LDL-C) is well known to result in cardiovascular disease. Mainstay therapy for reducing LDL-C and ASCVD risk is statin therapy. Despite achieving desired LDL-C levels with lipid-lowering therapy, cardiovascular residual risk often persists. Elevated lipoprotein(a) [Lp(a)] levels have been highlighted as an inherent independent predictor of ASCVD, and decreasing Lp(a) levels may result in a significant reduction in the residual risk in high-risk patients. To date, there are no approved medications to lower Lp(a) levels. Nicotinic acid, proprotein convertase subtilisin/kexin 9 inhibitors, and antisense oligonucleotide have demonstrated modest to potent Lp(a) reduction. Spotlight has been placed on antisense oligonucleotides and their role in Lp(a) lowering. APO(a)LRx is in the frontline for selectively decreasing Lp(a) concentrations and ongoing research may prove that this medication may lower Lp(a)-mediated residual risk, translating into cardiovascular benefit.

How low is safe? The frontier of very low (<30 mg/dL) LDL cholesterol

Low-density lipoprotein cholesterol (LDL-C) is a proven causative factor for developing atherosclerotic cardiovascular disease. Individuals with genetic conditions associated with lifelong very low LDL-C levels can be healthy. We now possess the pharmacological armamentarium (statins, ezetimibe, PCSK9 inhibitors) to reduce LDL-C to an unprecedented extent. Increasing numbers of patients are expected to achieve very low (<30 mg/dL) LDL-C. Cardiovascular event reduction increases log linearly in association with lowering LDL-C, without reaching any clear plateau even when very low LDL-C levels are achieved. It is still controversial whether lower LDL-C levels are associated with significant clinical adverse effects (e.g. new-onset diabetes mellitus or possibly haemorrhagic stroke) and long-term data are needed to address safety concerns. This review presents the familial conditions characterized by very low LDL-C, analyses trials with lipid-lowering agents where patients attained very low LDL-C, and summarizes the benefits and potential adverse effects associated with achieving very low LDL-C. Given the potential for cardiovascular benefit and short-term safe profile of very low LDL-C, it may be advantageous to attain such low levels in specific high-risk populations. Further studies are needed to compare the net clinical benefit of non-LDL-C-lowering interventions with very low LDL-C approaches, in addition to comparing the efficacy and safety of very low LDL-C levels vs. current recommended targets.

Saudi Familial Hypercholesterolemia Patients With Rare LDLR Stop Gain Variant Showed Variable Clinical Phenotype and Resistance to Multiple Drug Regimen

Familial hypercholesterolemia (FH), a well-known lipid disease caused by inherited genetic defects in cholesterol uptake and metabolism is underdiagnosed in many countries including Saudi Arabia. The present study aims to identify the molecular basis of severe clinical manifestations of FH patients from unrelated Saudi consanguineous families. Two Saudi families with multiple FH patients fulfilling the combined FH diagnostic criteria of Simon Broome Register, and the Dutch Lipid Clinic Network (DLCN) were recruited. LipidSeq, a targeted resequencing panel for monogenic dyslipidemias, was used to identify causative pathogenic mutation in these two families and in 92 unrelated FH cases. Twelve FH patients from two unrelated families were sharing a very rare, pathogenic and founder LDLR stop gain mutation i.e., c.2027delG (p.Gly676Alafs^*33) in both the homozygous or heterozygous states, but not in unrelated patients. Based on the variant zygosity, a marked phenotypic heterogeneity in terms of LDL-C levels, clinical presentations and resistance to anti-lipid treatment regimen (ACE inhibitors, β-blockers, ezetimibe, statins) of the FH patients was observed. This loss-of-function mutation is predicted to alter the free energy dynamics of the transcribed RNA, leading to its instability. Protein structural mapping has predicted that this non-sense mutation eliminates key functional domains in LDLR, which are essential for the receptor recycling and LDL particle binding. In conclusion, by combining genetics and structural bioinformatics approaches, this study identified and characterized a very rare FH causative LDLR pathogenic variant determining both clinical presentation and resistance to anti-lipid drug treatment.

The Role of RNA-Targeted Therapeutics to Reduce ASCVD Risk: What Have We Learned Recently?

PURPOSE OF REVIEW

To discuss advances on the RNA-targeted therapies to treat dyslipidemia with the aim of reducing atherosclerotic cardiovascular disease (ASCVD).

RECENT FINDINGS

Genetic studies have paved the way for therapies that reduce translation of proteins that play causal roles in dyslipidemia and atherosclerosis like proprotein convertase subtilisin/kexin type 9 (PCSK9), apolipoprotein B-100 (apoB), apolipoprotein(a) [apo(a)], apolipoprotein C3 (apoC3), and angiopoietin-like 3 (ANGPTL3). Either antisense oligonucleotide (ASO) therapies and small interfering RNA (siRNA) molecules inhibit protein synthesis and consequently improve dyslipidemia. Most of these molecules contain N-acetylgalactosamine (GalNAc) moieties that have high specificity for hepatocytes and therefore reduce concentration in other tissues. Inclisiran, an siRNA for PCSK9, has shown robust LDL-C reductions, with good tolerability, in severe forms of hypercholesterolemia as well as in high cardiovascular disease patients with injections every 3 to 6 months. Pelacarsen is an ASO against apolipoprotein(a) that reduces Lp(a) up to 80% with good tolerability. Either inclisiran or pelacarsen is being tested to show it can prevent ASCVD. AMG 890, an siRNA compound aimed at reducing apo(a) synthesis, is also under investigation. Volanesorsen is an ASO against apoC3 that reduces triglyceride levels up to 70% and is being tested in severe hypertriglyceridemic patients. Vupanorsen is an ASO against ANGPTL3 that reduced triglyceride levels 36-53% among moderate hypertriglyceridemic individuals. Interestingly, it also reduces ApoC3 and non-HDL cholesterol and apoB; however, it lowers HDL cholesterol. RNA-targeted therapies are being extensively tested for dyslipidemia treatment with promising results.

Novel RNAi-Based Therapies for Atherosclerosis

PURPOSE OF REVIEW

Atherosclerosis, defined by inflammation and accumulation of cholesterol, extracellular matrix, and cell debris into the arteries is a common factor behind cardiovascular diseases (CVD), such as coronary artery disease, peripheral artery disease, and stroke. In this review, we discuss and describe novel RNA interference (RNAi)-based therapies in clinical trials and on the market.

RECENT FINDINGS

The first RNAi-based therapies have entered clinical use for the control of atherosclerosis risk factors, i.e., blood cholesterol levels. The most advanced treatment is silencing of proprotein convertase subtilisin/kexin type 9 (PCSK9) with a drug called inclisiran, which has been approved for the treatment of hypercholesterolemia in late 2020, and results in a robust decrease in plasma cholesterol levels. As the new RNAi therapies for atherosclerosis are now entering markets, the usefulness of these therapies will be further evaluated in larger patient cohorts. Thus, it remains to be seen how fast, effectively and eminently these new drugs consolidate their niche within the cardiovascular disease drug palette.

Managing dyslipidemia in patients with Type 2 diabetes

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is associated with increased risk for atherosclerotic cardiovascular disease (ASCVD) which is partly related to atherogenic dyslipidemia with raised triglycerides, reduced high-density lipoprotein cholesterol levels, and accompanying lipid changes. Treatment of this dyslipidemia is regarded as a priority to reduce the ASCVD risk in T2DM.

AREAS COVERED

This article reviews the relevant studies and guidelines from the publications related to this area.

EXPERT OPINION

Lifestyle modification should always be encouraged, and statin treatment is indicated in most patients with T2DM based on the outcome of randomized controlled trials. If LDL-C goals are not achieved, first, ezetimibe and subsequently proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors should be added. Patients with T2DM derive greater benefits from ezetimibe and PCSK9 inhibitors due to their higher absolute ASCVD risk compared to patients without T2DM. If triglyceride levels remain elevated, a high dose of eicosapentaenoic acid ethyl ester should be added. Fibrates should be used for severe hypertriglyceridemia to prevent acute pancreatitis. Novel treatments including pemafibrate and inclisiran are undergoing cardiovascular outcome trials, and RNA-based therapies may help to target residual hypertriglyceridemia and high lipoprotein(a) with the long acting treatments offering potential improved adherence to therapy.

Translating genetic association of lipid levels for biological and clinical application

PURPOSE OF REVIEW

This review focuses on the foundational evidence from the last two decades of lipid genetics research and describes the current status of data-driven approaches for transethnic GWAS, fine-mapping, transcriptome informed fine-mapping, and disease prediction.

RECENT FINDINGS

Current lipid genetics research aims to understand the association mechanisms and clinical relevance of lipid loci as well as to capture population specific associations found in global ancestries. Recent genome-wide trans-ethnic association meta-analyses have identified 118 novel lipid loci reaching genome-wide significance. Gene-based burden tests of whole exome sequencing data have identified three genes-PCSK9, LDLR, and APOB-with significant rare variant burden associated with familial dyslipidemia. Transcriptome-wide association studies discovered five previously unreported lipid-associated loci. Additionally, the predictive power of genome-wide genetic risk scores amalgamating the polygenic determinants of lipid levels can potentially be used to increase the accuracy of coronary artery disease prediction.

CONCLUSIONS

Lipids are one of the most successful group of traits in the era of genome-wide genetic discovery for identification of novel loci and plausible drug targets. However, a substantial fraction of lipid trait heritability remains unexplained. Further analysis of diverse ancestries and state of the art methods for association locus refinement could potentially reveal some of this missing heritability and increase the clinical application of the genomic association results.

Integrated multiplatform-based metabonomics and network analysis to explore the mechanism of Polygonum cuspidatum on hyperlipidemia

Hyperlipidemia is a major risk factor and pathological basis for cardiovascular diseases. Polygonum cuspidatum (HZ), a famous traditional Chinese medicine, is frequently used to treat hyperlipidemia. However, little is known about its underlying mechanism. Herein, an integrated approach combining multiplatform-based metabonomics and network analysis was adopted to elucidate the ameliorative mechanism of HZ on hyperlipidemia. The global metabolomic characters of HZ on hyperlipidemia were investigated by GC-MS and LC-MS based metabonomics. Significant metabonomic alterations were observed in hyperlipidemic group, which could be restored by HZ supplementation. Furthermore, the drug-ingredients-target-metabolic pathway network was constructed, and the result indicated that HZ exhibited hypolipidemic efficacy through resveratrol, polydatin, torachrysone-8-O-β-D-(6'-oxayl)-glucoside, physciondiglucoside, (+)-catechin, β-sitosterol, quercetin, luteolin and physovenine acting on phospholipase A2, unspecific monooxygenase, arachidonate 15-lipoxygenase, aromatic-L-amino-acid decarboxylase, alcohol dehydrogenase and triacylglycerol lipase. In conclusion, this study explored potential mechanism of HZ on hyperlipidemia with the aid of the integrated approach combining multiplatform-based metabonomics and network analysis, which might provide a theoretical basis for the clinical application of HZ.

Current Diagnosis and Management of Primary Chylomicronemia

Primary chylomicronemia (PCM) is a rare and intractable disease characterized by marked accumulation of chylomicrons in plasma. The levels of plasma triglycerides (TGs) typically range from 1,000 - 15,000 mg/dL or higher.

PCM is caused by defects in the lipoprotein lipase (LPL) pathway due to genetic mutations, autoantibodies, or unidentified causes. The monogenic type is typically inherited as an autosomal recessive trait with loss-of-function mutations in LPL pathway genes ( LPL , LMF1 , GPIHBP1 , APOC2 , and APOA5 ). Secondary/environmental factors (diabetes, alcohol intake, pregnancy, etc.) often exacerbate hypertriglyceridemia (HTG).

The signs, symptoms, and complications of chylomicronemia include eruptive xanthomas, lipemia retinalis, hepatosplenomegaly, and acute pancreatitis with onset as early as in infancy. Acute pancreatitis can be fatal and recurrent episodes of abdominal pain may lead to dietary fat intolerance and failure to thrive.

The main goal of treatment is to prevent acute pancreatitis by reducing plasma TG levels to at least less than 500-1,000 mg/dL. However, current TG-lowering medications are generally ineffective for PCM. The only other treatment options are modulation of secondary/environmental factors. Most patients need strict dietary fat restriction, which is often difficult to maintain and likely affects their quality of life.

Timely diagnosis is critical for the best prognosis with currently available management, but PCM is often misdiagnosed and undertreated. The aim of this review is firstly to summarize the pathogenesis, signs, symptoms, diagnosis, and management of PCM, and secondly to propose simple diagnostic criteria that can be readily translated into general clinical practice to improve the diagnostic rate of PCM. In fact, these criteria are currently used to define eligibility to receive social support from the Japanese government for PCM as a rare and intractable disease.

Nevertheless, further research to unravel the molecular pathogenesis and develop effective therapeutic modalities is warranted. Nationwide registry research on PCM is currently ongoing in Japan with the aim of better understanding the disease burden as well as the unmet needs of this life-threatening disease with poor therapeutic options.

From traditional pharmacological towards nucleic acid-based therapies for cardiovascular diseases

Nucleic acid-based therapeutics are currently developed at large scale for prevention and management of cardiovascular diseases (CVDs), since: (i) genetic studies have highlighted novel therapeutic targets suggested to be causal for CVD; (ii) there is a substantial recent progress in delivery, efficacy, and safety of nucleic acid-based therapies; (iii) they enable effective modulation of therapeutic targets that cannot be sufficiently or optimally addressed using traditional small molecule drugs or antibodies. Nucleic acid-based therapeutics include (i) RNA-targeted therapeutics for gene silencing; (ii) microRNA-modulating and epigenetic therapies; (iii) gene therapies; and (iv) genome-editing approaches (e.g. CRISPR-Cas-based): (i) RNA-targeted therapeutics: several large-scale clinical development programmes, using antisense oligonucleotides (ASO) or short interfering RNA (siRNA) therapeutics for prevention and management of CVD have been initiated. These include ASO and/or siRNA molecules to lower apolipoprotein (a) [apo(a)], proprotein convertase subtilisin/kexin type 9 (PCSK9), apoCIII, ANGPTL3, or transthyretin (TTR) for prevention and treatment of patients with atherosclerotic CVD or TTR amyloidosis. (ii) MicroRNA-modulating and epigenetic therapies: novel potential therapeutic targets are continually arising from human non-coding genome and epigenetic research. First microRNA-based therapeutics or therapies targeting epigenetic regulatory pathways are in clinical studies. (iii) Gene therapies: EMA/FDA have approved gene therapies for non-cardiac monogenic diseases and LDL receptor gene therapy is currently being examined in patients with homozygous hypercholesterolaemia. In experimental studies, gene therapy has significantly improved cardiac function in heart failure animal models. (iv) Genome editing approaches: these technologies, such as using CRISPR-Cas, have proven powerful in stem cells, however, important challenges are remaining, e.g. low rates of homology-directed repair in somatic cells such as cardiomyocytes. In summary, RNA-targeted therapies (e.g. apo(a)-ASO and PCSK9-siRNA) are now in large-scale clinical outcome trials and will most likely become a novel effective and safe therapeutic option for CVD in the near future. MicroRNA-modulating, epigenetic, and gene therapies are tested in early clinical studies for CVD. CRISPR-Cas-mediated genome editing is highly effective in stem cells, but major challenges are remaining in somatic cells, however, this field is rapidly advancing.

Risk stratification of ST-segment elevation myocardial infarction (STEMI) patients using machine learning based on lipid profiles

BACKGROUND

Numerous studies have revealed the relationship between lipid expression and increased cardiovascular risk in ST-segment elevation myocardial infarction (STEMI) patients. Nevertheless, few investigations have focused on the risk stratification of STEMI patients using machine learning algorithms.

METHODS

A total of 1355 STEMI patients who underwent percutaneous coronary intervention were enrolled in this study during 2015-2018. Unsupervised machine learning (consensus clustering) was applied to the present cohort to classify patients into different lipid expression phenogroups, without the guidance of clinical outcomes. Kaplan-Meier curves were implemented to show prognosis during a 904-day median follow-up (interquartile range: 587-1316). In the adjusted Cox model, the association of cluster membership with all adverse events including all-cause mortality, all-cause rehospitalization, and cardiac rehospitalization was evaluated.

RESULTS

All patients were classified into three phenogroups, 1, 2, and 3. Patients in phenogroup 1 with the highest Lp(a) and the lowest HDL-C and apoA1 were recognized as the statin-modified cardiovascular risk group. Patients in phenogroup 2 had the highest HDL-C and apoA1 and the lowest TG, TC, LDL-C and apoB. Conversely, patients in phenogroup 3 had the highest TG, TC, LDL-C and apoB and the lowest Lp(a). Additionally, phenogroup 1 had the worst prognosis. Furthermore, a multivariate Cox analysis revealed that patients in phenogroup 1 were at significantly higher risk for all adverse outcomes.

CONCLUSION

Machine learning-based cluster analysis indicated that STEMI patients with increased concentrations of Lp(a) and decreased concentrations of HDL-C and apoA1 are likely to have adverse clinical outcomes due to statin-modified cardiovascular risks.

TRIAL REGISTRATION

ChiCTR1900028516 ( http://www.chictr.org.cn/index.aspx ).

Bempedoic acid. Mechanism of action and pharmacokinetic and pharmacodynamic properties

Bempedoic acid acts by inhibiting adenosine triphosphate-citrate lyase (ACL) and consequently cholesterol biosynthesis, leading to increased expression of LDL receptors and increasing low-density lipoproteins (LDL-C) plasma clearence. It is a prodrug for oral administration with intracellular activation. It is activatedin liver cells and to a lesser extent in kidney cells, being absent in adipose tissue and muscle cells. Therefore, unlike statins, its potential myotoxic effect is very limited. It has recently been approved as a lipid-lowering drug in combination with diet, with statins, or with other lipid-lowering drugs in patients with hypercholesterolaemia, mixed dyslipidaemia, statin intolerance, or when these are contraindicated. The marketing of bempedoic acid implies, in clinical practice, having a new family of lipid-lowering drugs.