Antisense inhibition of apolipoprotein (a) to lower plasma lipoprotein (a) levels in humans

New insights into the therapeutic options to lower lipoprotein(a)

BACKGROUND

Elevated levels of lipoprotein(a) [Lp(a)] represent a risk factor for cardiovascular disease including aortic valve stenosis, myocardial infarction and stroke. While the patho-physiological mechanisms linking Lp(a) with atherosclerosis are not fully understood, from genetic studies that lower Lp(a) levels protect from CVD independently of other risk factors including lipids and lipoproteins. Hereby, Lp(a) has been considered an appealing pharmacological target.

RESULTS

However, approved lipid lowering therapies such as statins, ezetimibe or PCSK9 inhibitors have a neutral to modest effect on Lp(a) levels, thus prompting the development of new strategies selectively targeting Lp(a). These include antisense oligonucleotides and small interfering RNAs (siRNAs) directed towards apolipoprotein(a) [Apo(a)], which are in advanced phase of clinical development. More recently, additional approaches including inhibitors of Apo(a) and gene editing approaches via CRISPR-Cas9 technology entered early clinical development.

CONCLUSION

If the results from the cardiovascular outcome trials, designed to demonstrate whether the reduction of Lp(a) of more than 80% as observed with pelacarsen, olpasiran or lepodisiran translates into the decrease of cardiovascular mortality and major adverse cardiovascular events, will be positive, lowering Lp(a) will become a new additional target in the management of patients with elevated cardiovascular risk.

The Essence of Lipoproteins in Cardiovascular Health and Diseases Treated by Photodynamic Therapy

Lipids, together with lipoprotein particles, are the cause of atherosclerosis, which is a pathology of the cardiovascular system. In addition, it affects inflammatory processes and affects the vessels and heart. In pharmaceutical answer to this, statins are considered a first-stage treatment method to block cholesterol synthesis. Many times, additional drugs are also used with this method to lower lipid concentrations in order to achieve certain values of low-density lipoprotein (LDL) cholesterol. Recent advances in photodynamic therapy (PDT) as a new cancer treatment have gained the therapy much attention as a minimally invasive and highly selective method. Photodynamic therapy has been proven more effective than chemotherapy, radiotherapy, and immunotherapy alone in numerous studies. Consequently, photodynamic therapy research has expanded in many fields of medicine due to its increased therapeutic effects and reduced side effects. Currently, PDT is the most commonly used therapy for treating age-related macular degeneration, as well as inflammatory diseases, and skin infections. The effectiveness of photodynamic therapy against a number of pathogens has also been demonstrated in various studies. Also, PDT has been used in the treatment of cardiovascular diseases, such as atherosclerosis and hyperplasia of the arterial intima. This review evaluates the effectiveness and usefulness of photodynamic therapy in cardiovascular diseases. According to the analysis, photodynamic therapy is a promising approach for treating cardiovascular diseases and may lead to new clinical trials and management standards. Our review addresses the used therapeutic strategies and also describes new therapeutic strategies to reduce the cardiovascular burden that is induced by lipids.

Novel therapeutic targets and emerging treatments for atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of morbidity and mortality worldwide. Even with excellent control of low-density lipoprotein cholesterol (LDL-C) levels, adverse cardiovascular events remain a significant clinical problem worldwide, including among those without any traditional ASCVD risk factors. It is necessary to identify novel sources of residual risk and to develop targeted strategies that address them. Lipoprotein(a) has become increasingly recognized as a new cardiovascular risk determinant. Large-scale clinical trials have also signalled the potential additive cardiovascular benefits of decreasing triglycerides beyond lowering LDL-C levels. Since CANTOS (Anti-inflammatory Therapy with Canakinumab for Atherosclerotic Disease) demonstrated that antibodies against interleukin-1β may decrease recurrent cardiovascular events in secondary prevention, various anti-inflammatory medications used for rheumatic conditions and new monoclonal antibody therapeutics have undergone rigorous evaluation. These data build towards a paradigm shift in secondary ASCVD prevention, underscoring the value of targeting multiple biological pathways in the management of both lipid levels and systemic inflammation. Evolving knowledge of the immune system, and the gut microbiota may result in opportunities for modifying previously unrecognized sources of residual inflammatory risk. This review provides an overview of novel therapeutic targets for ASCVD and emerging treatments with a focus on mechanisms, efficacy, and safety.

The Promise of PCSK9 and Lipoprotein(a) as Targets for Gene Silencing Therapies

PURPOSE

High plasma concentrations of LDL and lipoprotein(a) (Lp[a]) are independent and causal risk factors for atherosclerotic cardiovascular disease (ASCVD). There is an unmet therapeutic need for high-risk patients with elevated levels of LDL-C and/or Lp(a). Recent advances in the development of nucleic acids for gene silencing (ie, triantennary N-acetylgalactosamine conjugated antisense-oligonucleotides [ASOs] and small interfering RNA [siRNA]) targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) and Lp(a) offer effective and sustainable therapies.

METHODS

Related articles in the English language were identified through a search for original and review articles in the PubMed database using the following key terms: cardiovascular disease, dyslipidemia, PCSK9 inhibitors, Lp(a), LDL-cholesterol, familial hypercholesterolemia, siRNA, and antisense oligonucleotide and clinical trials (either alone or in combination).

FINDINGS

Inclisiran, the most advanced siRNA-treatment targeting hepatic PCSK9, is well tolerated, producing a >30% reduction on LDL-C levels in randomized controlled trials. Pelacarsen is the most clinical advanced ASO, whereas olpasiran and SLN360 are the 2 siRNAs directed against the mRNA of the LPA gene. Evidence suggests that all Lp(a)-targeting agents are safe and well tolerated, with robust and sustained reduction in plasma Lp(a) concentration up to 70% to 90% in individuals with elevated Lp(a) levels.

IMPLICATIONS

Cumulative evidence from clinical trials supports the value of ASO and siRNA therapies targeting the synthesis of PCSK9 and Lp(a) for lowering LDL-C and Lp(a) in patients with established ASCVD or high risk of ASCVD. Further research is needed to examine whether gene silencing therapy could improve clinical outcomes in patients with elevated LDL and/or Lp(a) levels. Confirmation of the tolerability and cost-effectiveness of long-term inhibition of PCSK9 and Lp(a) with this approach is essential.

Lipoprotein(a) as a Risk Factor for Cardiovascular Diseases: Pathophysiology and Treatment Perspectives

Cardiovascular disease (CVD) is still a leading cause of morbidity and mortality, despite all the progress achieved as regards to both prevention and treatment. Having high levels of lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease that operates independently. It can increase the risk of developing cardiovascular disease even when LDL cholesterol (LDL-C) levels are within the recommended range, which is referred to as residual cardiovascular risk. Lp(a) is an LDL-like particle present in human plasma, in which a large plasminogen-like glycoprotein, apolipoprotein(a) [Apo(a)], is covalently bound to Apo B100 via one disulfide bridge. Apo(a) contains one plasminogen-like kringle V structure, a variable number of plasminogen-like kringle IV structures (types 1-10), and one inactive protease region. There is a large inter-individual variation of plasma concentrations of Lp(a), mainly ascribable to genetic variants in the Lp(a) gene: in the general po-pulation, Lp(a) levels can range from <1 mg/dL to >1000 mg/dL. Concentrations also vary between different ethnicities. Lp(a) has been established as one of the risk factors that play an important role in the development of atherosclerotic plaque. Indeed, high concentrations of Lp(a) have been related to a greater risk of ischemic CVD, aortic valve stenosis, and heart failure. The threshold value has been set at 50 mg/dL, but the risk may increase already at levels above 30 mg/dL. Although there is a well-established and strong link between high Lp(a) levels and coronary as well as cerebrovascular disease, the evidence regarding incident peripheral arterial disease and carotid atherosclerosis is not as conclusive. Because lifestyle changes and standard lipid-lowering treatments, such as statins, niacin, and cholesteryl ester transfer protein inhibitors, are not highly effective in reducing Lp(a) levels, there is increased interest in developing new drugs that can address this issue. PCSK9 inhibitors seem to be capable of reducing Lp(a) levels by 25-30%. Mipomersen decreases Lp(a) levels by 25-40%, but its use is burdened with important side effects. At the current time, the most effective and tolerated treatment for patients with a high Lp(a) plasma level is apheresis, while antisense oligonucleotides, small interfering RNAs, and microRNAs, which reduce Lp(a) levels by targeting RNA molecules and regulating gene expression as well as protein production levels, are the most widely explored and promising perspectives. The aim of this review is to provide an update on the current state of the art with regard to Lp(a) pathophysiological mechanisms, focusing on the most effective strategies for lowering Lp(a), including new emerging alternative therapies. The purpose of this manuscript is to improve the management of hyperlipoproteinemia(a) in order to achieve better control of the residual cardiovascular risk, which remains unacceptably high.

Lipoprotein(a) and risk of cognitive impairment in Black and White Americans: the Reasons for Geographic and Racial Differences in Stroke cohort

Background

Cognitive impairment has a substantial vascular etiology. Higher lipoprotein(a) [Lp(a)] is associated with cardiovascular disease risk, but its association with cognitive function is uncertain. We hypothesized that Lp(a) is a risk factor for cognitive impairment, a relationship that would be modified by race and sex.

Objectives

To study the association of Lp(a) with cognitive impairment in a biracial cohort.

Methods

The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study recruited 30,239 Black and White Americans aged >45 years from 2003 to 2007. After 3.4 years, among participants with normal baseline cognition, baseline Lp(a) was measured in 434 cases of incident cognitive impairment and 557 controls. Cognitive impairment was defined as scores below the sixth percentile based on age, sex, race, and education norms on 2 or 3 components of a 3-test battery administered every 2 years.

Results

Median Lp(a) was higher in Black than in White individuals. Among Black participants, the adjusted odds ratio (OR) of cognitive impairment per SD higher increment Lp(a) was 1.39 (95% CI: 1.05, 1.84). The OR in White participants was 1.03 (95% CI: 0.87, 1.21; P for race difference = .03). The relationship of Lp(a) with cognitive trajectory differed by sex and race. Elevated Lp(a) was associated with worse baseline memory in Black men and a steeper trajectory of verbal fluency decline in Black men than in White men and women.

Conclusion

Higher Lp(a) was associated with increased risk of cognitive impairment in Black but not White individuals. Future studies should evaluate the biological and social mechanisms through which race and Lp(a) interact to increase risk of cognitive impairment.

Potential Novel RNA-Targeting Agents for Effective Lipoprotein(a) Lowering: A Systematic Assessment of the Evidence From Completed and Ongoing Developmental Clinical Trials

ABSTRACT

An increase in blood lipoprotein (a) [Lp(a)] levels, mostly genetically determined, has been identified as an independent risk factor of atherosclerotic cardiovascular disease. No drug has yet been approved that markedly lowers Lp(a) and thereby reduces residual cardiovascular risk. The aim of this article was to critically review the evidence from clinical development studies to date on the efficacy and safety of new RNA-based therapeutics for targeted lowering of Lp(a). PubMed/MEDLINE, Scopus, Web of Science, and ClinicalTrials.gov were searched without any language or date restriction up to November 5, 2022, and a total of 12 publications and 22 trial records were included. Several drugs were found that are currently in various stages of clinical development, such as the antisense oligonucleotide pelacarsen and the small interfering RNA molecule olpasiran and drugs coded as SLN360 and LY3819469. Among them, pelacarsen has progressed the most, currently reaching phase 3. All these drugs have so far shown satisfactory pharmacokinetic properties, consistently high and stable, dose-dependent efficacy in lowering Lp(a) even by more than 90%, with an acceptable safety profile in subjects with highly elevated Lp(a). In addition, reports of early clinical trials with pelacarsen imply a promising suppressive effect on key mechanisms of atherogenesis. Future research should focus on confirming these beneficial clinical effects in patients with lower average Lp(a) levels and clearly demonstrating the association between lowering Lp(a) and reducing adverse cardiovascular outcomes.

On-treatment platelet reactivity through the thromboxane A2 or P2Y12 platelet receptor pathways is not affected by pelacarsen

BACKGROUND

Pelacarsen decreases plasma levels of lipoprotein(a) [Lp(a)] and oxidized phospholipids (OxPL). It was previously reported that pelacarsen does not affect the platelet count. We now report the effect of pelacarsen on on-treatment platelet reactivity.

METHODS

Subjects with established cardiovascular disease and screening Lp(a) levels ≥60 mg per deciliter (~ ≥150 nmol/L) were randomized to receive pelacarsen (20, 40, or 60 mg every 4 weeks; 20 mg every 2 weeks; or 20 mg every week), or placebo for 6-12 months. Aspirin Reaction Units (ARU) and P2Y12 Reaction Units (PRU) were measured at baseline and the primary analysis timepoint (PAT) at 6 months.

RESULTS

Of the 286 subjects randomized, 275 had either an ARU or PRU test, 159 (57.8%) were on aspirin alone and 94 (34.2%) subjects were on dual anti-platelet therapy. As expected, the baseline ARU and PRU were suppressed in subjects on aspirin or on dual anti-platelet therapy, respectively. There were no significant differences in baseline ARU in the aspirin groups or in PRU in the dual anti-platelet groups. At the PAT there were no statistically significant differences in ARU in subjects on aspirin or PRU in subjects on dual anti-platelet therapy among any of the pelacarsen groups compared to the pooled placebo group (p > 0.05 for all comparisons).

CONCLUSION

Pelacarsen does not modify on-treatment platelet reactivity through the thromboxane A₂ or P2Y12 platelet receptor pathways.

Genetics of aortic valve disease

PURPOSE OF REVIEW

Aortic valve disease is a leading global cause of morbidity and mortality, posing an increasing burden on society. Advances in next-generation technologies and disease models over the last decade have further delineated the genetic and molecular factors that might be exploited in development of therapeutics for affected patients. This review describes several advances in the molecular and genetic understanding of AVD, focusing on bicuspid aortic valve (BAV) and calcific aortic valve disease (CAVD).

RECENT FINDINGS

Genomic studies have identified a myriad of genes implicated in the development of BAV, including NOTCH1 , SMAD6 and ADAMTS19 , along with members of the GATA and ROBO gene families. Similarly, several genes associated with the initiation and progression of CAVD, including NOTCH1 , LPA , PALMD , IL6 and FADS1/2 , serve as the launching point for emerging clinical trials.

SUMMARY

These new insights into the genetic contributors of AVD have offered new avenues for translational disease investigation, bridging molecular discoveries to emergent pharmacotherapeutic options. Future studies aimed at uncovering new genetic associations and further defining implicated molecular pathways are fuelling the new wave of drug discovery.

Emerging Therapies for the Treatment of Atherosclerotic Cardiovascular Disease: From Bench to Bedside

Primarily a consequence of sedentary lifestyle, atherosclerosis has already reached pandemic proportions, and with every year the burden of it is only increasing. As low-density lipoprotein cholesterol (LDL-C) represents a crucial factor in atherosclerosis formation and progression, stringent lipid-lowering therapy could conceivably be the key to preventing the unfavorable outcomes that arise as a consequence of atherosclerosis. The use of statins in lipid-lowering is often burdened by adverse events or is insufficient to prevent cardiovascular events as a monotherapy. Therefore, in the present review, the authors aimed to discuss the underlying mechanisms of dyslipidemia and associated atherosclerotic cardiovascular disease (ASCVD) and preclinical and clinical trials of novel therapeutic approaches to its treatment, some of which are still in the early stages of development. Apart from novel therapies, a novel change in perspective is needed. Specifically, the critical objective in the future management of ASCVD is to embrace emerging evidence in the field of atherosclerosis, because clinicians are often burden by common practice and personal experience, both of which have so far been shown to be futile in the setting of atherosclerosis.

Association of vitamins, minerals, and lead with lipoprotein(a) in a cross-sectional cohort of US adults

Lipoprotein(a)(Lp[a]) is a low-density lipoprotein-cholesterol (LDL-C)-like particle with potent pro-atherothrombotic properties. The association of Lp(a) with several circulating factors, including vitamins, remains unresolved. We performed an observational analysis using the National Health and Nutrition Examination Survey III cohort, a cohort used to monitor the nutrition status of US-citizens. We used multivariable linear regression to test associations of Lp(a) and LDL-C with levels of serum vitamins and minerals and whole-blood lead. Analyses controlled for factors known to associate with Lp(a) (age, sex, race/ethnicity, statin use, hemoglobin A1c, body mass index, hypertension, diabetes, glomerular filtration rate, alcohol intake, and saturated fat intake). LDL-C was corrected for Lp(a) mass. Multiple sensitivity tests were performed, including considering factors as categorical variables (deficient, normal, elevated). Among 7,662 subjects, Lp(a) correlated (β-coefficient) positively (change per 1 conventional unit increase) with carotenoids (lycopene (0.17(0.06,0.28), p=0.005), lutein (0.19(0.07,0.30), p=0.002), β-cryptoxanthin (0.21(0.05,0.37), p=0.01), β-carotene (0.05(0.02,0.09), p=0.003), and α-carotene (0.15(0.01,0.30), p=0.04)) and lead (0.54(0.03,1.05), p=0.04) levels when tested as continuous variables. LDL-C had similar associations. Lp(a) did not associate with vitamins A, B12, C, or E retinyl esters, folate, RBC-folate, selenium, ferritin, transferrin saturation, or calcium. With factors as categorical variables, Lp(a) but not LDL-C negatively associated with elevated vitamin B12 (-5.41(-9.50, -1.53), p=0.01) and folate (-2.86(-5.09, -0.63), p=0.01). In conclusion, Lp(a) associated similarly to LDL-C when vitamins, minerals, and lead were tested as continuous variables, while only Lp(a) correlated with vitamin B12 and folate when tested as categorical variables. These observations are hypotheses generating and require further studies to determine causality.

Lipoprotein(a): Its Association with Calcific Aortic Valve Stenosis, the Emerging RNA-Related Treatments and the Hope for a New Era in “Treating” Aortic Valve Calcification

The treatment of patients with aortic valve calcification (AVC) and calcific aortic valve stenosis (CAVS) remains challenging as, until today, all non-invasive interventions have proven fruitless in preventing the disease’s onset and progression. Despite the similarities in the pathogenesis of AVC and atherosclerosis, statins failed to show a favorable effect in preventing AVC progression. The recognition of lipoprotein(a) [Lp(a)] as a strong and potentially modifiable risk factor for the development and, perhaps, the progression of AVC and CAVS and the evolution of novel agents leading in a robust Lp(a) reduction, have rekindled hope for a promising future in the treatment of those patients. Lp(a) seems to promote AVC via a ‘three hit’ mechanism including lipid deposition, inflammation and autotaxin transportation. All of these lead to valve interstitial cells transition into osteoblast-like cells and, thus, to parenchymal calcification. Currently available lipid-lowering therapies have shown a neutral or mild effect on Lp(a), which was proven insufficient to contribute to clinical benefits. The short-term safety and the efficacy of the emerging agents in reducing Lp(a) have been proven; nevertheless, their effect on cardiovascular risk is currently under investigation in phase 3 clinical trials. A positive result of these trials will probably be the spark to test the hypothesis of the modification of AVC’s natural history with the novel Lp(a)-lowering agents.

Lipoprotein(a) in Atherosclerotic Diseases: From Pathophysiology to Diagnosis and Treatment

Lipoprotein(a) (Lp(a)) is a low-density lipoprotein (LDL) cholesterol-like particle bound to apolipoprotein(a). Increased Lp(a) levels are an independent, heritable causal risk factor for atherosclerotic cardiovascular disease (ASCVD) as they are largely determined by variations in the Lp(a) gene (LPA) locus encoding apo(a). Lp(a) is the preferential lipoprotein carrier for oxidized phospholipids (OxPL), and its role adversely affects vascular inflammation, atherosclerotic lesions, endothelial function and thrombogenicity, which pathophysiologically leads to cardiovascular (CV) events. Despite this crucial role of Lp(a), its measurement lacks a globally unified method, and, between different laboratories, results need standardization. Standard antilipidemic therapies, such as statins, fibrates and ezetimibe, have a mediocre effect on Lp(a) levels, although it is not yet clear whether such treatments can affect CV events and prognosis. This narrative review aims to summarize knowledge regarding the mechanisms mediating the effect of Lp(a) on inflammation, atherosclerosis and thrombosis and discuss current diagnostic and therapeutic potentials.

Efficacy and safety of pelacarsen in lowering Lp(a) in healthy Japanese subjects

BACKGROUND

Pelacarsen is a liver-targeted antisense oligonucleotide that potently lowers lipoprotein(a) [Lp(a)] levels. Its safety and efficacy in diverse populations has not been extensively studied.

OBJECTIVE

To assess the effect of pelacarsen, including monthly dosing of 80 mg, in subjects of Japanese ancestry.

METHODS

A randomized double-blind, placebo-controlled, study was performed in 29 healthy Japanese subjects treated with single ascending doses (SAD) of pelacarsen 20, 40 and 80 mg subcutaneously or multiple doses (MD) of pelacarsen 80 mg monthly for 4 doses. The primary objective was to assess the safety and tolerability in healthy Japanese subjects; secondary objectives to assess the pharmacokinetics of pelacarsen; and exploratory objective to determine the effect of pelacarsen on plasma Lp(a) levels.

RESULTS

No serious adverse events or clinically relevant abnormalities in any laboratory parameters were noted. In the MD cohort, mean plasma concentrations of pelacarsen peaked at ∼4 hours and declined in a bi-exponential manner thereafter. In the SAD cohorts, the placebo-corrected least-square mean (PCLSM) percent changes in Lp(a) at Day 30 were: -55.4% (p=0.0008), -58.9% (p=0.0003) and -73.7% (p<0.0001) for the 20 mg, 40 mg, and 80 mg pelacarsen-treated groups, respectively. In the MD cohort, the PCLSM at Days 29, 85, 113, 176 and 204 were -84.0% (p=0.0003), -106.2% (p<0.0001), -70.0 (p<0.0001), -80.0% (p=0.0104) and -55.8% (p=0.0707), respectively.

CONCLUSIONS

Pelacarsen demonstrates an acceptable safety and tolerability profile and potently lowers plasma levels of Lp(a) in healthy Japanese subjects, including with the 80 mg monthly dose being evaluated in the Lp(a) HORIZON trial.

Dyslipidemia - the known unknown

Dyslipidemia (DLP) is the most important risk factor for atherosclerotic cardiovascular disease (ASCVD) and, in the context of severe hypertriglyceridemia (TG > 10 mmol/l), a risk factor for the development of acute pancreatitis. The prevalence of DLP is very high, but their control, especially among the patients at highest risk, is often inadequate. When diagnosing DLP, we should always exclude its possible secondary aetiology (e.g. DLP in the context of hypothyroidism, diabetes, ...). Based on the assessment of the overall CV risk (according to SCORE2/SCORE2-OP or according to the comorbidities of the individual), target values for blood lipids, especially LDL-cholesterol, are determined according to the risk category. The basis of the management of DLP in the prevention of ASCVD is dietary and regimen measures, followed by adequate lipid-lowering therapy in indicated cases. As of April 2023, the portfolio of lipid-lowering medication has been expanded to include inclisiran (small interfering RNA against proprotein convertase subtilisin/kexin type 9 (PCSK9)), which is administered directly in cardiologists' and internists' outpatient clinics, ensuring 100% adherence. In severe hypertriglyceridaemia, fibrate monotherapy may be indicated in addition to dietary and regimen measures; if this treatment fails, some patients may be offered lomitapide, volanesorsen or evinacumab as part of clinical trials or specific treatment programmes if very strict indication criteria are met.

Lipoprotein (a) Levels and Abdominal Aortic Aneurysm. A Systematic Review and Meta-analysis

BACKGROUND

Several studies have linked high Lipoprotein (a) (Lp(a)) concentrations to cardiovascular events, including the formation of Abdominal Aortic Aneurysms (AAA). We review and meta-analyze existing evidence on the association of Lp(a) levels with AAA.

METHODS

Studies evaluating the link of Lp(a) with AAA, up to December 27th 2021, were identified by a systematic search of PubMed, SCOPUS, and Web of Science databases. The results were qualitatively and quantitatively synthesized according to PRISMA guidelines. Results are presented as standardized mean differences (SMD) with 95% confidence intervals (CI).

RESULTS

A total of 5,078 subjects (1,637 patients with AAA vs. 3,441 controls) from 11 studies were included in the meta-analysis, with a mean age of 69.9 years and a male sex prevalence of 85.8%. Based on the qualitative synthesis, high Lp(a) concentrations are linked to abdominal aortic wall degradation and extracellular matrix disarrangement. Moreover, despite the considerable variability among races, high Lp(a) levels are related to increased AAA risk, independently of race differences. Accordingly, patients with AAA displayed significantly higher Lp(a) levels compared to controls (SMD: 0.86, 95% CI: 0.55-1.17, p < 0.001). The outcome was not affected in a sensitivity analysis excluding three outlying studies (SMD: 0.40, 95% CI: 0.22-0.58, p < 0.001).

CONCLUSION

This meta-analysis indicates the association between high Lp(a) levels and the presence of AAA, although existing literature presents high heterogeneity. Further studies are needed to standardize Lp(a) measurements and to conclude whether Lp(a) can be used as a sensitive biomarker of early presymptomatic AAA diagnosis.

Pharmacotherapy for children with elevated levels of lipoprotein(a): future directions

INTRODUCTION

Elevated lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD). With the advent of the antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs) targeted at LPA, the gene encoding apolipoprotein(a), that are highly effective for lowering Lp(a) levels, this risk factor might be managed in the near future. Given that Lp(a) levels are mostly genetically determined and once elevated, present from early age, we have evaluated future directions for the treatment of children with high Lp(a) levels.

AREAS COVERED

In the current review, we discuss different pharmacological treatments in clinical development and provide an in-depth overview of the effects of ASOs and siRNAs targeted at LPA.

EXPERT OPINION

Since high Lp(a) is an important risk factor for ASCVD and given the promising effects of both ASOs and siRNAs targeted at apo(a), there is an urgent need for well-designed prospective studies to assess the impact of elevated Lp(a) in childhood. If the Lp(a)-hypothesis is confirmed in adults, and also in children, the rationale might arise for treating children with high Lp(a) levels. However, we feel that this should be limited to children with the highest cardiovascular risk including familial hypercholesterolemia and potentially pediatric stroke.

Pharmacokinetics, Pharmacodynamics, and Tolerability of Olpasiran in Healthy Japanese and Non-Japanese Participants: Results from a Phase I, Single-dose, Open-label Study

PURPOSE

Olpasiran, an N-acetyl galactosamine-conjugated, hepatocyte-targeted, small interfering RNA, is being developed to reduce plasma lipoprotein (Lp)-(a) concentration by directly targeting the LPA gene. This study evaluated the pharmacokinetics, pharmacodynamics, and tolerability of a single SC injection of olpasiran in healthy, Japanese and non-Japanese participants.

METHODS

In this Phase I, open-label, parallel-design study, Japanese participants were randomized in a 1:1:1:1 ratio to receive a single 3, 9, 75, or 225 mg dose of olpasiran. Non-Japanese participants received a single 75 mg dose of olpasiran. The primary end points were pharmacokinetic parameters, including C_max, AUC_inf, t_max, and t_1/2. Tolerability and change in Lp(a) concentration were also assessed.

FINDINGS

A total of 27 enrolled participants had a mean (SD) age of 48.0 (12.5) years. Olpasiran C_max and AUC_inf were increased in an approximately dose-proportional manner in the Japanese groups. Mean (SD) C_max values were 242 (121.0) and 144 (71.3) ng/mL, and mean (SD) AUC_inf values were 3550 (592.0) and 2620 (917.0) h·ng/mL, in the Japanese and non-Japanese groups, respectively, given 75 mg of olpasiran. Median t_max ranged from 3.0 to 9.0 hours and mean (SD) t_1/2 ranged from 4.0 (0.3) to 6.9 (1.6) hours across all groups. The maximal Lp(a) reduction occurred at day 57, with mean (SD) Lp(a) percentage reductions from baseline ranging from 56.0% (21.0%) to 99.0% (0.2%). A reductions in Lp(a) was observed as early as day 4. All adverse events were mild in severity, with no serious or fatal adverse events. No clinically important changes in tolerability-related laboratory analytes or vital signs were observed.

IMPLICATIONS

In this population of healthy Japanese participants, dose-proportional increases in exposure and reduced Lp(a) in a dose-dependent manner were found with single 3, 9, 75, and 225 mg doses of olpasiran. The magnitude and durability of Lp(a) reductions were similar between the Japanese and non-Japanese groups. Olpasiran was well tolerated, with no clinically important adverse events or laboratory or vital sign abnormalities.

Elevated lipoprotein(a) levels as an independent predictor of long-term recurrent events in patients with acute coronary syndrome: an observational, retrospective cohort study

BACKGROUND

Whether lipoprotein(a) [Lp(a)] is associated with recurrent cardiovascular events (RCVEs) still remains controversial. The present study aimed to investigate the prognostic value of Lp(a) for long-term RCVEs and each component of it in people with acute coronary syndrome (ACS).

METHODS

This multicenter, observational and retrospective study enrolled 765 ACS patients at 11 hospitals in Chengdu from January 2014 to June 2019. Patients were assigned to low-Lp(a) group [Lp(a) < 30 mg/dl] and high-Lp(a) group [Lp(a) ≥ 30 mg/dl]. The primary and secondary endpoints were defined as RCVEs and their elements, including all-cause death, nonfatal myocardial infarction (MI), nonfatal stroke and unplanned revascularization.

RESULTS

Over a median 17-month follow-up, 113 (14.8%) patients presented with RCVEs were reported, among which we observed 57 (7.5%) all-cause deaths, 22 (2.9%) cases of nonfatal stroke, 13 (1.7%) cases of nonfatal MI and 33 (4.3%) cases of unplanned revascularization. The incidences of RCVEs and revascularization in the high-Lp(a) group were significantly higher than those in the low-Lp(a) group ( P < 0.05), whereas rates of all-cause death, nonfatal stroke and nonfatal MI were not statistically different ( P > 0.05). Kaplan-Meier analysis also revealed the same trend. Multivariate Cox proportional hazards analysis showed that 1-SD increase of Lp(a) was independently associated with both the primary endpoint event [hazard ratio (HR), 1.285 per 1-SD; 95% confidence interval (CI), 1.112-1.484; P < 0.001] and revascularization (HR, 1.588 per 1-SD; 95% CI, 1.305-1.932; P < 0.001), but not with the other secondary events.

CONCLUSION

Increased Lp(a) is an independent predictor of RCVEs and unplanned revascularization in patients with ACS.

Decoding microRNA drivers in Atherosclerosis

An estimated 97% of the human genome consists of non-protein-coding sequences. As our understanding of genome regulation improves, this has led to the characterization of a diverse array of non-coding RNAs (ncRNA). Among these, micro-RNAs (miRNAs) belong to the short ncRNA class (22–25 nucleotides in length), with approximately 2500 miRNA genes encoded within the human genome. From a therapeutic perspective, there is interest in exploiting miRNA as biomarkers of disease progression and response to treatments, as well as miRNA mimics/repressors as novel medicines. miRNA have emerged as an important class of RNA master regulators with important roles identified in the pathogenesis of atherosclerotic cardiovascular disease. Atherosclerosis is characterized by a chronic inflammatory build-up, driven largely by low-density lipoprotein cholesterol accumulation within the artery wall and vascular injury, including endothelial dysfunction, leukocyte recruitment and vascular remodelling. Conventional therapy focuses on lifestyle interventions, blood pressure-lowering medications, high-intensity statin therapy and antiplatelet agents. However, a significant proportion of patients remain at increased risk of cardiovascular disease. This continued cardiovascular risk is referred to as residual risk. Hence, a new drug class targeting atherosclerosis could synergise with existing therapies to optimise outcomes. Here, we review our current understanding of the role of ncRNA, with a focus on miRNA, in the development and progression of atherosclerosis, highlighting novel biological mechanisms and therapeutic avenues.

A method for lipoprotein (a) Isolation from a small volume of plasma with applications for clinical research

High levels of circulating Lipoprotein (a) [Lp(a)] are an independent risk factor for CVD. One of the major limitations to investigating Lp(a) biology is the need for large volumes of plasma (4-10 mL) for its isolation. We developed an isolation technique requiring only 0.4 mL of plasma yielding an enriched Lp(a) fraction suitable for compositional and functional studies. We collected plasma from patients (n = 9) in EDTA presenting to our Center for Preventive Cardiology for CVD risk management and with circulating Lp(a) > 66 mg/dL. 0.4 mL of plasma was added to 90 µL of potassium bromide (1.33 g/mL) and subjected to our two-step density-gradient ultracentrifugation method. The first step separates VLDL and LDL from the Lp(a) and HDL fractions and the second step further separates VLDL from LDL and Lp(a) from HDL. Lp(a) is then dialyzed for up to 24 h in potassium phosphate buffer. We performed cholesterol gel electrophoresis, immunoblotting and LC-MS/MS proteomics on isolated lipoprotein fractions to confirm fraction enrichment. Functional studies including Lp(a)-dependent induction of macrophage gene expression and cholesterol efflux inhibition were performed on isolated Lp(a) to confirm its preserved bioactivity. Lp(a) yields (264 ± 82.3 µg/mL on average) correlated with Lp(a) plasma concentrations (r2 = 0.75; p < 0.01) and represented the relative distribution of circulating apo(a) isoforms. Proteomic analyses confirm lipoprotein fraction separation. Functional integrity was confirmed by the findings that isolated Lp(a) inhibited plasminogen-dependent cholesterol efflux in HEK293T cells expressing ABCA1 and increased expressions of Il1b, Nos2 and Ccl2. We developed a small-volume isolation technique for Lp(a) suited for a range of applications used in biomedical research. The use of this technique circumvents volume-dependent limitations and expands our ability to investigate the mysteries of this deleterious lipoprotein.

Effect of Pelacarsen on Lipoprotein(a) Cholesterol and Corrected Low-Density Lipoprotein Cholesterol

BACKGROUND

Laboratory methods that report low-density lipoprotein cholesterol (LDL-C) include both LDL-C and lipoprotein(a) cholesterol [Lp(a)-C] content.

OBJECTIVES

The purpose of this study was to assess the effect of pelacarsen on directly measured Lp(a)-C and LDL-C corrected for its Lp(a)-C content.

METHODS

The authors evaluated subjects with a history of cardiovascular disease and elevated Lp(a) randomized to 5 groups of cumulative monthly doses of 20-80 mg pelacarsen vs placebo. Direct Lp(a)-C was measured on isolated Lp(a) using LPA4-magnetic beads directed to apolipoprotein(a). LDL-C was reported as: 1) LDL-C as reported by the clinical laboratory; 2) LDL-C_corr = laboratory-reported LDL-C - direct Lp(a)-C; and 3) LDL-C_corrDahlén = laboratory LDL-C - [Lp(a) mass × 0.30] estimated by the Dahlén formula.

RESULTS

The baseline median Lp(a)-C values in the groups ranged from 11.9 to 15.6 mg/dL. Compared with placebo, pelacarsen resulted in dose-dependent decreases in Lp(a)-C (2% vs -29% to -67%; P = 0.001-<0.0001). Baseline laboratory-reported mean LDL-C ranged from 68.5 to 89.5 mg/dL, whereas LDL-C_corr ranged from 55 to 74 mg/dL. Pelacarsen resulted in mean percent/absolute changes of -2% to -19%/-0.7 to -8.0 mg/dL (P = 0.95-0.05) in LDL-C_corr, -7% to -26%/-5.4 to -9.4 mg/dL (P = 0.44-<0.0001) in laboratory-reported LDL-C, and 3.1% to 28.3%/0.1 to 9.5 mg/dL (P = 0.006-0.50) increases in LDL-C_corrDahlén. Total apoB declined by 3%-16% (P = 0.40-<0.0001), but non-Lp(a) apoB was not significantly changed.

CONCLUSIONS

Pelacarsen significantly lowers direct Lp(a)-C and has neutral to mild lowering of LDL-C_corr. In patients with elevated Lp(a), LDL-C_corr provides a more accurate reflection of changes in LDL-C than either laboratory-reported LDL-C or the Dahlén formula.

Calcific Aortic Stenosis-A Review on Acquired Mechanisms of the Disease and Treatments

Calcific aortic stenosis is a progressive disease that has become more prevalent in recent decades. Despite advances in research to uncover underlying biomechanisms, and development of new generations of prosthetic valves and replacement techniques, management of calcific aortic stenosis still comes with unresolved complications. In this review, we highlight underlying molecular mechanisms of acquired aortic stenosis calcification in relation to hemodynamics, complications related to the disease, diagnostic methods, and evolving treatment practices for calcific aortic stenosis.

Elevated Lipoprotein(a): Background, Current Insights and Future Potential Therapies

Lipoprotein(a) forms a subfraction of the lipid profile and is characterized by the addition of apolipprotein(a) (apo(a)) to apoB100 derived particles. Its levels are mostly genetically determined inversely related to the number of protein domain (kringle) repeats in apo(a). In epidemiological studies, it shows consistent association with cardiovascular disease (CVD) and most recently with extent of aortic stenosis. Issues with standardizing the measurement of Lp(a) are being resolved and consensus statements favor its measurement in patients at high risk of, or with family histories of CVD events. Major lipid-lowering therapies such as statin, fibrates, and ezetimibe have little effect on Lp(a) levels. Therapies such as niacin or cholesterol ester transfer protein (CETP) inhibitors lower Lp(a) as well as reducing other lipid-related risk factors but have failed to clearly reduce CVD events. Proprotein convertase subtilisin kexin-9 (PCSK9) inhibitors reduce cholesterol and Lp(a) as well as reducing CVD events. New antisense therapies specifically targeting apo(a) and hence Lp(a) have greater and more specific effects and will help clarify the extent to which intervention in Lp(a) levels will reduce CVD events.

The current landscape of lipoprotein(a) in calcific aortic valvular disease

PURPOSE OF REVIEW

Calcific aortic stenosis (CAVS) is the most common form of valvular heart disease in developed countries, increasing in prevalence with the aging population. Surgical or transcatheter aortic valve replacement is the only treatment available for CAVS. However, these interventions are typically reserved for severe symptomatic aortic stenosis (AS). The purpose of this review is to summarize the recent literature in uncovering the underlying pathophysiology of CAVS in the setting of lipoprotein (a) [Lp(a)] and emerging therapies targeting Lp(a) which may help halt disease progression in CAVS.

RECENT FINDINGS

Pathophysiologic, epidemiological, and genetic studies over the past two decades have provided strong evidence that Lp(a) is an important mediator of calcific aortic valvular disease (CAVD). Studies suggest that Lp(a) is a key carrier of pro-calcifying oxidized phospholipids (OxPL). The metabolism of OxPL results in a pro-inflammatory state and subsequent valvular thickening and mineralization through pro-osteogenic signaling. The identification of Lp(a) as a causal mediator of CAVD has allowed for opportunities for emerging therapeutic agents which may slow the progression of CAVD (Fig. 1JOURNAL/cocar/04.03/00001573-202109000-00007/figure1/v/2021-08-04T080204Z/r/image-jpeg).

SUMMARY

This review summarizes the current knowledge on the association of Lp(a) with CAVD and ongoing studies of potential Lp(a)-lowering therapies. Based on the rate-limiting and causal role of Lp(a) in progression of CAVS, these therapies may represent novel pharmacotherapies in AS and inform the developing role of Lp(a) in the clinical management of CAVD.

Multifactorial Basis and Therapeutic Strategies in Metabolism-Related Diseases

Throughout the 20th and 21st centuries, the incidence of non-communicable diseases (NCDs), also known as chronic diseases, has been increasing worldwide. Changes in dietary and physical activity patterns, along with genetic conditions, are the main factors that modulate the metabolism of individuals, leading to the development of NCDs. Obesity, diabetes, metabolic associated fatty liver disease (MAFLD), and cardiovascular diseases (CVDs) are classified in this group of chronic diseases. Therefore, understanding the underlying molecular mechanisms of these diseases leads us to develop more accurate and effective treatments to reduce or mitigate their prevalence in the population. Given the global relevance of NCDs and ongoing research progress, this article reviews the current understanding about NCDs and their related risk factors, with a focus on obesity, diabetes, MAFLD, and CVDs, summarizing the knowledge about their pathophysiology and highlighting the currently available and emerging therapeutic strategies, especially pharmacological interventions. All of these diseases play an important role in the contamination by the SARS-CoV-2 virus, as well as in the progression and severity of the symptoms of the coronavirus disease 2019 (COVID-19). Therefore, we briefly explore the relationship between NCDs and COVID-19.

Prevalence and influence of LPA gene variants and isoform size on the Lp(a)-lowering effect of pelacarsen

BACKGROUND AND AIMS

Antisense oligonucleotides (ASOs) targeting LPA to lower lipoprotein(a) [Lp(a]] are in clinical trials. Patients have been recruited according to various Lp(a) thresholds, but the prevalence of LPA genetic variants and their effect on efficacy of these ASOs are not well described.

METHODS

We analyzed data from 4 clinical trials of the ASO pelacarsen targeting apolipoprotein(a) that included 455 patients. Common LPA genetic variants rs10455872 and rs3798220, major and minor isoform size, and changes in Lp(a), LDL-C, apoB, OxPL-apoB and OxPL-apo(a) were analyzed according to categories of baseline Lp(a).

RESULTS

The prevalence of carrier status for rs10455872 and rs3798220 combined ranged from 25.9% in patients with Lp(a) in the 75 - <125 nmol/L range to 77.1% at Lp(a) ≥375 nmol/L. The prevalence of homozygosity for rs3798220, rs10455872 and for double heterozygosity in category of Lp(a) ≥375 nmol/L was 6.3%, 14.6% and 12.5%, respectively. Isoform size decreased with increasing Lp(a) plasma levels, with 99.3% of patients with Lp(a) ≥175 nmol/L having ≤20 KIV repeats in the major isoform. The mean percent reduction from baseline in Lp(a), OxPL-apoB and OxPL-apo(a) in response to pelacarsen was not affected by the presence of rs10455872 and rs3798220, isoform size or baseline Lp(a) at all doses studied.

CONCLUSIONS

In patients randomized to Lp(a) lowering trials, LPA genetic variants are common, but a sizable proportion do not carry common variants associated with elevated Lp(a). In contrast, the major isoform size was almost uniformly ≤20 KIV repeats in patients with Lp(a) ≥175 nmol/L. The Lp(a) and OxPL lowering effects of pelacarsen were independent of both LPA genetic variants and isoform size.

Emerging RNA Therapeutics to Lower Blood Levels of Lp(a): JACC Focus Seminar 2/4

Lipoprotein(a) [Lp(a)] has risen to the level of an accepted cardiovascular disease risk factor, but final proof of causality awaits a randomized trial of Lp(a) lowering. Inhibiting apolipoprotein(a) production in the hepatocyte with ribonucleic acid therapeutics has emerged as an elegant and effective solution to reduce plasma Lp(a) levels. Phase 2 clinical trials have shown that the antisense oligonucleotide pelacarsen reduced mean Lp(a) levels by 80%, allowing 98% of subjects to reach on-treatment levels of <125 nmol/l (∼50 mg/dl). The phase 3 Lp(a)HORIZON (Assessing the Impact of Lipoprotein(a) Lowering With TQJ230 on Major Cardiovascular Events in Patients With CVD) outcomes trial is currently enrolling approximately 7,680 patients with history of myocardial infarction, ischemic stroke, and symptomatic peripheral arterial disease and controlled low-density lipoprotein cholesterol to pelacarsen versus placebo. The co-primary endpoints are major adverse cardiovascular events in subjects with Lp(a) >70 mg/dl and >90 mg/dl, in which either of the two being positive will lead to a successful trial. Additional ribonucleic acid-targeted therapies to lower Lp(a) are in preclinical and clinical development. The testing of the Lp(a) hypothesis will provide proof whether Lp(a)-mediated risk can be abolished by potent Lp(a) lowering.

Lipoprotein(a): a genetic marker for cardiovascular disease and target for emerging therapies

Lipoprotein(a) [Lp(a)] is an established cardiovascular risk factor, and growing evidence indicates its causal association with atherosclerotic disease because of the proatherogenic low-density lipoprotein (LDL)-like properties and the prothrombotic plasminogen-like activity of apolipoprotein(a) [apo(a)]. As genetics significantly influences its plasma concentration, Lp(a) is considered an inherited risk factor of atherosclerotic cardiovascular disease (ASCVD), especially in young individuals. Moreover, it has been suggested that elevated Lp(a) may significantly contribute to residual cardiovascular risk in patients with coronary artery disease and optimal LDL-C levels. Nonetheless, the fascinating hypothesis that lowering Lp(a) could reduce the risk of cardiovascular events - in primary or secondary prevention - still needs to be demonstrated by randomized clinical trials. To date, no specific Lp(a)-lowering agent has been approved for reducing the lipoprotein levels, and current lipid-lowering drugs have limited effects. In the future, emerging therapies targeting Lp(a) may offer the possibility to further investigate the relation between Lp(a) levels and cardiovascular outcomes in randomized controlled trials, ultimately leading to a new era in cardiovascular prevention. In this review, we aim to provide an updated overview of current evidence on Lp(a) as well as currently investigated therapeutic strategies that specifically address the reduction of the lipoprotein.

Recent Updates of Lipoprotein(a) and Cardiovascular Disease

In recent years, epidemiological studies, genome-wide association studies, and Mendelian randomization studies have shown a strong association between increased levels of lipoproteins and increased risks of coronary heart disease and cardiovascular disease (CVD). Although lipoprotein(a) [Lp(a)] was an independent risk factor for ASCVD, the latest international clinical guidelines do not recommend direct reduction of plasma Lp(a) concentrations. The main reason was that there is no effective clinical medicine that directly lowers plasma Lp(a) concentrations. However, recent clinical trials have shown that proprotein convertase subtilisin/kexin-type 9 inhibitors (PCSK9) and second-generation antisense oligonucleotides can effectively reduce plasma Lp(a) levels. This review will present the structure, pathogenicity, prognostic evidences, and recent advances in therapeutic drugs for Lp(a).

The association between lipoprotein (a) and carotid atherosclerosis in patients with type 2 diabetes without pre-existing cardiovascular disease: A cross-sectional study

AIMS

Lipoprotein (a) [Lp(a)] has been considered a determinant of residual cardiovascular risk. We aimed to investigate associations between serum Lp(a) levels and carotid atherosclerosis.

METHODS

This cross-sectional study included 662 type 2 diabetic patients without cardiovascular disease. The mean value of three right and left measurements was used to indentify increased carotid intima-media thickness (CIMT). A carotid plaque was defined as a focal wall thickening >50% of the surrounding IMT or its CIMT ≥1.5 mm. The presence of carotid atherosclerosis was defined as having CIMT ≥1.0 mm or carotid plaque.

RESULTS

A total of 34.3% of patients had carotid atherosclerosis. The median Lp(a) level was significantly higher in subjects with carotid atherosclerosis (14.6 vs. 10.2 mg/dL, P < 0.001). The log-transformed Lp(a) level per 1-standard deviation increase was significantly associated with higher risk of the presence of carotid atherosclerosis (odds ratio [OR] 1.46; 95% confidence interval [CI] 1.16 - 1.84, P = 0.001) after adjusting other parameters. The log Lp(a) level was still significantly associated with the risk of carotid atherosclerosis in subjects with optimal low-density lipoprotein cholesterol (LDL-C) <100 mg/dL (OR 1.48; 95% CI 1.16 - 1.88, P = 0.001). Higher Lp(a) and LDL-C had an additive effect on the presence of carotid atherosclerosis.

CONCLUSION

Elevated Lp(a) was significantly associated with the presence of carotid atherosclerosis in patients with type 2 diabetes, independent of conventional cardiometabolic risk factors.

Lp(a) (Lipoprotein[a]) Concentrations and Incident Atherosclerotic Cardiovascular Disease: New Insights From a Large National Biobank

OBJECTIVE

Lp(a) (lipoprotein[a]) concentrations are associated with atherosclerotic cardiovascular disease (ASCVD), and new therapies that enable potent and specific reduction are in development. In the largest study conducted to date, we address 3 areas of uncertainty: (1) the magnitude and shape of ASCVD risk conferred across the distribution of lipoprotein(a) concentrations; (2) variation of risk across racial and clinical subgroups; (3) clinical importance of a high lipoprotein(a) threshold to guide therapy. Approach and Results: Relationship of lipoprotein(a) to incident ASCVD was studied in 460 506 middle-aged UK Biobank participants. Over a median follow-up of 11.2 years, incident ASCVD occurred in 22 401 (4.9%) participants. Median lipoprotein(a) concentration was 19.6 nmol/L (25th-75th percentile 7.6-74.8). The relationship between lipoprotein(a) and ASCVD appeared linear across the distribution, with a hazard ratio of 1.11 (95% CI, 1.10-1.12) per 50 nmol/L increment. Substantial differences in concentrations were noted according to race-median values for white, South Asian, black, and Chinese individuals were 19, 31, 75, and 16 nmol/L, respectively. However, risk per 50 nmol/L appeared similar-hazard ratios of 1.11, 1.10, and 1.07 for white, South Asian, and black individuals, respectively. A high lipoprotein(a) concentration defined as ≥150 nmol/L was present in 12.2% of those without and 20.3% of those with preexisting ASCVD and associated with hazard ratios of 1.50 (95% CI, 1.44-1.56) and 1.16 (95% CI, 1.05-1.27), respectively.

CONCLUSIONS

Lipoprotein(a) concentrations predict incident ASCVD among middle-aged adults within primary and secondary prevention contexts, with a linear risk gradient across the distribution. Concentrations are variable across racial subgroups, but the associated risk appears similar.

Antisense technology: A review

Antisense technology is beginning to deliver on the broad promise of the technology. Ten RNA-targeted drugs including eight single-strand antisense drugs (ASOs) and two double-strand ASOs (siRNAs) have now been approved for commercial use, and the ASOs in phase 2/3 trials are innovative, delivered by multiple routes of administration and focused on both rare and common diseases. In fact, two ASOs are used in cardiovascular outcome studies and several others in very large trials. Interest in the technology continues to grow, and the field has been subject to a significant number of reviews. In this review, we focus on the molecular events that result in the effects observed and use recent clinical results involving several different ASOs to exemplify specific molecular mechanisms and specific issues. We conclude with the prospective on the technology.

Long-term secondary cardiovascular prevention programme in patients subjected to coronary artery bypass surgery

AIMS

Patients with coronary heart disease (CHD) are at very high risk of recurrent events. A strategy to reduce excess risk might be to deliver structured secondary prevention programmes, but their efficacy has been mostly evaluated in the short term and in experimental settings. This is a retrospective case-control study aimed at assessing, in the real world, the efficacy of a secondary prevention programme in reducing long-term coronary event recurrences after coronary artery bypass surgery (CABG).

METHODS AND RESULTS

Programme participants (henceforth 'cases') were men and women aged <75 years subjected to CABG between 2002 and 2014, living within 100 km of the hospital. Key programme actions included optimization of treatments according to the most updated European preventive guidelines, surveillance of therapy adherence, and customized lifestyle counselling. Controls were analogous patients not involved in the programme because living farther than 100 km away, matched 1:1 with cases for gender, age at CABG, and year of CABG. Both groups (n = 1248) underwent usual periodic cardiology follow-up at our centre. Data on symptomatic or silent CHD recurrences were obtained from the hospital electronic health records. Cox analysis (adjusted for baseline differences between groups) shows that programme participation was associated with a significantly lower incidence throughout 5 years post-CABG of symptomatic [hazard ratio (95% confidence interval): 0.59 (0.38-0.94)] and silent [0.53 (0.31-0.89)] coronary recurrences.

CONCLUSION

In a real-world setting, taking part in a structured longstanding secondary prevention programme, in addition to usual cardiology care, meaningfully lowers the risk of coronary recurrences.

Identifying Genetic and Biological Determinants of Race-Ethnic Disparities in Stroke in the United States

In the United States, causes of racial differences in stroke and its risk factors remain only partly understood, and there is a long-standing disparity in stroke incidence and mortality impacting Black Americans. Only half of the excess risk of stroke in the United States Black population is explained by traditional risk factors, suggesting potential effects of other factors including genetic and biological characteristics. Here, we nonsystematically reviewed candidate laboratory biomarkers for stroke and their relationships to racial disparities in stroke. Current evidence indicates that IL-6 (interleukin-6), a proinflammatory cytokine, mediates racial disparities in stroke through its association with traditional risk factors. Only one reviewed biomarker, Lp(a) (lipoprotein[a]), is a race-specific risk factor for stroke. Lp(a) is highly genetically determined and levels are substantially higher in Black than White people; clinical and pharmaceutical ramifications for stroke prevention remain uncertain. Other studied stroke risk biomarkers did not explain racial differences in stroke. More research on Lp(a) and other biological and genetic risk factors is needed to understand and mitigate racial disparities in stroke.

The role of Lipoprotein(a) in cardiovascular disease: Current concepts and future perspectives

High lipoprotein(a) [Lp(a)] levels are associated with the development of atherosclerotic cardiovascular disease (ASCVD) and with calcific aortic valve stenosis (CAVS) both observationally and causally from human genetic studies. The mechanisms are not well characterized but likely involve its role as a carrier of oxidized phospholipids (OxPLs), which are known to be increased in pro-inflammatory states, to induce pro-inflammatory changes in monocytes leading to plaque instability, and to impair vascular endothelial cell function, a driver of acute and recurrent ischemic events. In addition, Lp(a) itself has prothrombotic activity. Current lipid-lowering strategies do not sufficiently lower Lp(a) serum levels. Lp(a)-specific-lowering drugs, targeting apolipoprotein(a) synthesis, lower Lp(a) by up to 90% and are being evaluated in ongoing clinical outcome trials. This review summarizes the current knowledge on the associations of Lp(a) with ASCVD and CAVS, the current role of Lp(a) assessment in the clinical setting, and emerging Lp(a)-specific-lowering therapies.

Investigation of a nonsense mutation located in the complex KIV-2 copy number variation region of apolipoprotein(a) in 10,910 individuals

Background

The concentrations of the highly atherogenic lipoprotein(a) [Lp(a)] are mainly genetically determined by the LPA gene locus. However, up to 70% of the coding sequence is located in the complex so-called kringle IV type 2 (KIV-2) copy number variation, a region hardly accessible by common genotyping and sequencing technologies. Despite its size, little is known about genetic variants in this complex region. The R21X variant is a functional variant located in this region, but it has never been analyzed in large cohorts.

Methods

We typed R21X in 10,910 individuals from three European populations using a newly developed high-throughput allele-specific qPCR assay. R21X allelic location was determined by separating the LPA alleles using pulsed-field gel electrophoresis (PFGE) and typing them separately. Using GWAS data, we identified a proxy SNP located outside of the KIV-2. Linkage disequilibrium was determined both statistically and by long-range haplotyping using PFGE. Worldwide frequencies were determined by reanalyzing the sequencing data of the 1000 Genomes Project with a dedicated pipeline.

Results

R21X carriers (frequency 0.016–0.021) showed significantly lower mean Lp(a) concentrations (− 11.7 mg/dL [− 15.5; − 7.82], p = 3.39e−32). The variant is located mostly on medium-sized LPA alleles. In the 1000 Genome data, R21X mostly occurs in Europeans and South Asians, is absent in Africans, and shows varying frequencies in South American populations (0 to 0.022). Of note, the best proxy SNP was another LPA null mutation (rs41272114, D′ = 0.958, R² = 0.281). D′ was very high in all 1000G populations (0.986–0.996), although rs41272114 frequency varies considerably (0–0.182). Co-localization of both null mutations on the same allele was confirmed by PFGE-based long-range haplotyping.

Conclusions

We performed the largest epidemiological study on an LPA KIV-2 variant so far, showing that it is possible to assess LPA KIV-2 mutations on a large scale. Surprisingly, in all analyzed populations, R21X was located on the same haplotype as the splice mutation rs41272114, creating “double-null” LPA alleles. Despite being a nonsense variant, the R21X status does not provide additional information beyond the rs41272114 genotype. This has important implications for studies using LPA loss-of-function mutations as genetic instruments and emphasizes the complexity of LPA genetics.

Lipoprotein(a) and Atherosclerotic Cardiovascular Disease: Current Understanding and Future Perspectives

PURPOSE

To review current knowledge of elevated lipoprotein(a) [Lp(a)] levels in relation to atherosclerotic cardiovascular disease (ASCVD) and discuss their potential use as biomarkers and therapeutic approaches in clinical practice.

METHODS

We summarized the current understanding and recent advances in the structure, metabolism, atherogenic mechanisms, standardized laboratory measurement, recommended screening populations, and prognostic value of Lp(a), with a special focus on the current potential treatment approaches for hyperlipoprotein(a)emia in patients with ASCVD.

RESULTS

Lp(a) is composed of LDL-like particle and characteristic apolipoprotein(a) [apo(a)] connected by a disulfide bond. Substantial evidence shows that elevated plasma Lp(a) level is a heritable, independent, and possibly causal risk factor for ASCVD through its proatherogenic, proinflammatory, and potentially prothrombotic properties. Current guidelines recommend Lp(a) measurement for patients with an intermediate-high risk of ASCVD, familial hypercholesterolemia, a family history of early ASCVD or elevated Lp(a), and progressive ASCVD despite receiving optimal therapy. Traditional Lp(a)-lowering approaches such as niacin, PCSK9 inhibitors, mipomersen, lomitapide, and lipoprotein apheresis were associated with a non-specific and limited reduction of Lp(a), intolerable side effects, invasive procedure, and high expense. The phase 2 randomized controlled trial of antisense oligonucleotide against the apo(a) encoding gene LPA mRNA showed that IONIS-APO(a)-L_RX could specifically reduce the level of Lp(a) by 90% with good tolerance, which may become a promising candidate for the prevention and treatment of ASCVD in the future.

CONCLUSIONS

It is reasonable to measure Lp(a) levels to reclassify ASCVD risk and manage individuals with elevated Lp(a) to further reduce the residual risk of ASCVD, especially with IONIS-APO(a)-L_RX.

Antisense lipoprotein[a] therapy: State-of-the-art and future perspectives

Several lines of evidence now attest that lipoprotein[a] (Lp[a]) is a significant risk factor for many cardiovascular disorders. This enigmatic lipoprotein, composed of a single copy of apolipoprotein B (apoB) and apolipoprotein[a] (apo [a]), expresses peculiar metabolism, virtually independent from lifestyle interventions. Several therapeutic options have hence been proposed for lowering elevated Lp[a] values, with or without concomitant effect on low density lipoprotein (LDL) particles, mostly encompassing statins, ezetimibe, nicotinic acid, lipoprotein apheresis, and anti-PCSK9 monoclonal antibodies. Since all these medical treatments have some technical and clinical drawbacks, a novel strategy is currently being proposed, based on the use of antisense apo[a] and/or apoB inhibitors. Although the role of these agents in hypercholesterolemic patients is now nearby entering clinical practice, the collection of information on Lp[a] is still underway. Preliminary evidence would suggest that apo[a] antisense therapy seems more appropriate in patients with isolated Lp[a] elevations, while apoB antisense therapy is perhaps more advisable in patients with isolated LDL elevations. In patients with concomitant elevations of Lp[a] and LDL, either combining the two apo[a] and apoB antisense therapies (a strategy which has never been tested), or the combination of well-known and relatively inexpensive drugs such as statins with antisense apo[a] inhibitors can be theoretically suggested. The results of an upcoming phase 3 study with antisense apo[a] inhibitors will hopefully provide definitive clues as to whether this approach may become the standard of care in patients with increased Lp[a] concentrations.

PCSK9 Inhibition with alirocumab increases the catabolism of lipoprotein(a) particles in statin-treated patients with elevated lipoprotein(a)

BACKGROUND

Lipoprotein(a) (Lp(a)) is a low-density lipoprotein (LDL) particle containing apolipoprotein(a) (apo(a)) covalently linked to apolipoprotein B-100 (apoB). Statin-treated patients with elevated Lp(a) have an increased risk of atherosclerotic cardiovascular disease (ASCVD). Recent trials show that proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition decreases Lp(a) and cardiovascular events, particularly in high risk patients with elevated Lp(a). We investigated the kinetic mechanism whereby alirocumab, a PCSK9 inhibitor, lowers Lp(a) in statin-treated patients with high Lp(a) and ASCVD.

METHODS

The effects of 12-week alirocumab treatment (150 mg every 2 weeks) on apo(a) kinetics were studied in 21 patients with elevated Lp(a) concentration (>0.5 g/L). Apo(a) fractional catabolic rate (FCR) and production rate (PR) were determined using intravenous D3-leucine administration, mass spectrometry and compartmental modelling. All patients were on long-term statin treatment.

RESULTS

Alirocumab significantly decreased plasma concentrations of total cholesterol (-39%), LDL-cholesterol (-67%), apoB (-56%), apo(a) (-25%) and Lp(a) (-22%) (P< 0.001 for all). Alirocumab also significantly lowered plasma apo(a) pool size (-26%, P <0.001) and increased the FCR of apo(a) (+28%, P< 0.001), but did not alter apo(a) PR, which remained significantly higher relative to a reference group of patients on statins with normal Lp(a) (P< 0.001).

CONCLUSIONS

In statin-treated patients, alirocumab lowers elevated plasma Lp(a) concentrations by accelerating the catabolism of Lp(a) particles. This may be consequent on marked upregulation of hepatic receptors (principally for LDL) and/or reduced competition between Lp(a) and LDL particles for these receptors; the mechanism could contribute to the benefit of PCSK9 inhibition with alirocumab on cardiovascular outcomes.

Genetics Insights in the Relationship Between Type 2 Diabetes and Coronary Heart Disease

Diabetes mellitus is a major risk factor for coronary heart disease (CHD). The major form of diabetes mellitus is type 2 diabetes mellitus (T2D), which is thus largely responsible for the CHD association in the general population. Recent years have seen major advances in the genetics of T2D, principally through ever-increasing large-scale genome-wide association studies. This article addresses the question of whether this expanding knowledge of the genomics of T2D provides insight into the etiologic relationship between T2D and CHD. We will investigate this relationship by reviewing the evidence for shared genetic loci between T2D and CHD; by examining the formal testing of this interaction (Mendelian randomization studies assessing whether T2D is causal for CHD); and then turn to the implications of this genetic relationship for therapies for CHD, for therapies for T2D, and for therapies that affect both. In conclusion, the growing knowledge of the genetic relationship between T2D and CHD is beginning to provide the promise for improved prevention and treatment of both disorders.

A genome-wide analysis of DNA methylation identifies a novel association signal for Lp(a) concentrations in the LPA promoter

Lipoprotein(a) [Lp(a)] is a major cardiovascular risk factor, which is largely genetically determined by one major gene locus, the LPA gene. Many aspects of the transcriptional regulation of LPA are poorly understood and the role of epigenetics has not been addressed yet. Therefore, we conducted an epigenome-wide analysis of DNA methylation on Lp(a) levels in two population-based studies (total n = 2208). We identified a CpG site in the LPA promoter which was significantly associated with Lp(a) concentrations. Surprisingly, the identified CpG site was found to overlap the SNP rs76735376. We genotyped this SNP de-novo in three studies (total n = 7512). The minor allele of rs76735376 (1.1% minor allele frequency) was associated with increased Lp(a) values (p = 1.01e-59) and explained 3.5% of the variation of Lp(a). Statistical mediation analysis showed that the effect on Lp(a) is rather originating from the base change itself and is not mediated by DNA methylation levels. This finding is supported by eQTL data from 208 liver tissue samples from the GTEx project, which shows a significant association of the rs76735376 minor allele with increased LPA expression. To evaluate, whether the association signal at rs76735376 may actually be derived from a stronger eQTL signal in LD with this SNP, eQTL association results of all correlated SNPs (r2≥0.1) were integrated with genetic association results. This analysis pinpointed to rs10455872 as the potential trigger of the effect of rs76735376. Furthermore, both SNPs coincide with short apo(a) isoforms. Adjusting for both, rs10455872 and the apo(a) isoforms diminished the effect size of rs76735376 to 5.38 mg/dL (p = 0.0463). This indicates that the effect of rs76735376 can be explained by both an independent effect of the SNP and a strong correlation with rs10455872 and apo(a) isoforms.

Prognostic impact of lipoprotein (a) on long-term clinical outcomes in diabetic patients on statin treatment after percutaneous coronary intervention

BACKGROUND

Serum levels of lipoprotein (a) [Lp(a)] have been reported as a residual risk marker for adverse events in patients with coronary artery disease (CAD). However, the prognostic impact of Lp(a) on long-term clinical outcomes among diabetic patients on statin therapy after percutaneous coronary intervention (PCI) remains unclear.

METHODS

The present investigation was a single-center, observational, retrospective cohort study. Among consecutive patients with CAD who underwent first PCI in our institution from 2000 to 2016, we enrolled diabetic patients on statin treatment. As a result, 927 patients (81% men; mean age, 67 years) were enrolled and divided into 2 groups according to a median Lp(a) level of 19.5 mg/dL. The incidence of major adverse cardiac events (MACE), including all-cause death, non-fatal myocardial infarction (MI), and non-fatal cerebral infarction (CI), was evaluated.

RESULT

No significant differences were seen in age, sex, smoking habits, hypertension, chronic kidney disease, or body mass index between high and low Lp(a) groups. During follow-up (median, 5.0 years; interquartile range, 1.9-9.7 years), MACE occurred in 90 cases (17.6%), including 40 (7.9%) cardiac deaths, 18 (3.6%) non-fatal MI, and 37 (7.9%) non-fatal CI. Frequency of MACE was significantly higher in the high-Lp(a) group than in the low-Lp(a) group (log-rank test, p = 0.002). Higher Lp(a) level at the time of PCI was significantly associated with higher frequency of MACE, even after adjusting for other covariates, including other lipid profiles (hazard ratio, 1.91; 95% confidence interval, 1.20-3.09; p = 0.006).

CONCLUSION

Our results demonstrated that in diabetic patients with CAD on statin treatment, increased Lp(a) levels could offer a good residual lipid risk marker. Assessing Lp(a) levels may be useful for risk stratification of long-term clinical outcomes after PCI, especially in diabetic patients.

Familial hypercholesterolemia and elevated lipoprotein(a): double heritable risk and new therapeutic opportunities

There is compelling evidence that the elevated plasma lipoprotein(a) [Lp(a)] levels increase the risk of atherosclerotic cardiovascular disease (ASCVD) in the general population. Like low-density lipoprotein (LDL) particles, Lp(a) particles contain cholesterol and promote atherosclerosis. In addition, Lp(a) particles contain strongly proinflammatory oxidized phospholipids and a unique apoprotein, apo(a), which promotes the growth of an arterial thrombus. At least one in 250 individuals worldwide suffer from the heterozygous form of familial hypercholesterolemia (HeFH), a condition in which LDL-cholesterol (LDL-C) is significantly elevated since birth. FH-causing mutations in the LDL receptor gene demonstrate a clear gene-dosage effect on Lp(a) plasma concentrations and elevated Lp(a) levels are present in 30-50% of patients with HeFH. The cumulative burden of two genetically determined pro-atherogenic lipoproteins, LDL and Lp(a), is a potent driver of ASCVD in HeFH patients. Statins are the cornerstone of treatment of HeFH, but they do not lower the plasma concentrations of Lp(a). Emerging therapies effectively lower Lp(a) by as much as 90% using RNA-based approaches that target the transcriptional product of the LPA gene. We are now approaching the dawn of an era, in which permanent and significant lowering of the high cholesterol burden of HeFH patients can be achieved. If outcome trials of novel Lp(a)-lowering therapies prove to be safe and cost-effective, they will provide additional risk reduction needed to effectively treat HeFH and potentially lower the CVD risk in these high-risk patients even more than currently achieved with LDL-C lowering alone.

Apolipoprotein(a) Kinetics in Statin-Treated Patients With Elevated Plasma Lipoprotein(a) Concentration

BACKGROUND

Lipoprotein(a) [Lp(a)] is a low-density lipoprotein‒like particle containing apolipoprotein(a) [apo(a)]. Patients with elevated Lp(a), even when treated with statins, are at increased risk of cardiovascular disease. We investigated the kinetic basis for elevated Lp(a) in these patients.

OBJECTIVES

Apo(a) production rate (PR) and fractional catabolic rate (FCR) were compared between statin-treated patients with and without elevated Lp(a).

METHODS

The kinetics of apo(a) were investigated in 14 patients with elevated Lp(a) and 15 patients with normal Lp(a) levels matched for age, sex, and body mass index using stable isotope techniques and compartmental modeling. All 29 patients were on background statin treatment. Plasma apo(a) concentration was measured using liquid chromatography-mass spectrometry.

RESULTS

The plasma concentration and PR of apo(a) were significantly higher in patients with elevated Lp(a) than in patients with normal Lp(a) concentration (all P < 0.01). The FCR of apo(a) was not significantly different between the groups. In univariate analysis, plasma concentration of apo(a) was significantly associated with apo(a) PR in both patient groups (r = 0.699 and r = 0.949, respectively; all P < 0.01). There was no significant association between plasma apo(a) concentration and FCR in either of the groups (r = 0.160 and r = -0.137, respectively).

CONCLUSION

Elevated plasma Lp(a) concentration is a consequence of increased hepatic production of Lp(a) particles in these patients. Our findings provide a kinetic rationale for the use of therapies that target the synthesis of apo(a) and production of Lp(a) particles in patients with elevated Lp(a).

Lipid-Lowering Agents

Several new or emerging drugs for dyslipidemia owe their existence, in part, to human genetic evidence, such as observations in families with rare genetic disorders or in Mendelian randomization studies. Much effort has been directed to agents that reduce LDL (low-density lipoprotein) cholesterol, triglyceride, and Lp[a] (lipoprotein[a]), with some sustained programs on agents to raise HDL (high-density lipoprotein) cholesterol. Lomitapide, mipomersen, AAV8.TBG.hLDLR, inclisiran, bempedoic acid, and gemcabene primarily target LDL cholesterol. Alipogene tiparvovec, pradigastat, and volanesorsen primarily target elevated triglycerides, whereas evinacumab and IONIS-ANGPTL3-L_Rx target both LDL cholesterol and triglyceride. IONIS-APO(a)-L_Rx targets Lp(a).

Lipoprotein(a) Elevation: A New Diagnostic Code with Relevance to Service Members and Veterans

Newly recognized as a clinical diagnosis, Lp(a) elevation is a major contributor to cardiovascular disease risk should be considered for patients with advanced premature atherosclerosis on imaging or a family history of premature cardiovascular disease, particularly when there are few traditional risk factors.

A new dawn for managing dyslipidemias: The era of rna-based therapies

The high occurrence of atherosclerotic cardiovascular disease (ASCVD) events is still a major public health issue. Although a major determinant of ASCVD event reduction is the absolute change of low-density lipoprotein-cholesterol (LDL-C), considerable residual risk remains and new therapeutic options are required, in particular, to address triglyceride-rich lipoproteins and lipoprotein(a) [Lp(a)]. In the era of Genome Wide Association Studies and Mendelian Randomization analyses aimed at increasing the understanding of the pathophysiology of ASCVD, RNA-based therapies may offer more effective treatment options. The advantage of oligonucleotide-based treatments is that drug candidates are targeted at highly specific regions of RNA that code for proteins that in turn regulate lipid and lipoprotein metabolism. For LDL-C lowering, the use of inclisiran - a silencing RNA that inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9) synthesis - has the advantage that a single s.c. injection lowers LDL-C for up to 6 months. In familial hypercholesterolemia, the use of the antisense oligonucleotide (ASO) mipomersen, targeting apolipoprotein (apoB) to reduce LDL-C, has been a valuable therapeutic approach, despite unquestionable safety concerns. The availability of specific ASOs lowering Lp(a) levels will allow rigorous testing of the Lp(a) hypothesis; by dramatically reducing plasma triglyceride levels, Volanesorsen (APOC3) and angiopoietin-like 3 (ANGPTL3)-LRx will further clarify the causality of triglyceride-rich lipoproteins in ASCVD. The rapid progress to date heralds a new dawn in therapeutic lipidology, but outcome, safety and cost-effectiveness studies are required to establish the role of these new agents in clinical practice.