Association of LPA Variants With Risk of Coronary Disease and the Implications for Lipoprotein(a)-Lowering Therapies: A Mendelian Randomization Analysis

Evaluation of lipoprotein(a) in the prevention and management of atherosclerotic cardiovascular disease: A survey among the Lipid Clinics Network

BACKGROUND AND AIMS

The European Atherosclerosis Society (EAS) Lipid Clinics Network promoted a survey in order to identify and understand how and when lipoprotein(a) [Lp(a)] is tested and clinically evaluated in lipid clinics throughout Europe, and the challenges that may prevent evaluation from being carried out.

METHODS

This survey was divided into three areas of inquiry: background and clinical setting information of clinicians, questions for doctors who claimed not to measure Lp(a), in order to understand what were the reasons for not ordering the test, and questions for doctors who measure Lp(a), to investigate the use of this value in the management of patients.

RESULTS

A total of 151 centres clinicians filled in the survey, out of 226 invited. The proportion of clinicians who declare to routinely measure Lp(a) in clinical practice was 75.5%. The most common reasons for not ordering the Lp(a) test were the lack of reimbursement or of treatment options, the non-availability of Lp(a) test, and the high cost of performing the laboratory test. The availability of therapies targeting this lipoprotein would result in a greater propensity of clinicians to start testing Lp(a). Among those who declared to routinely measure Lp(a), the Lp(a) measurement is mostly requested to further stratify patients' cardiovascular risk, and half of them recognized 50 mg/dL (approx. 110 nmol/L) as the threshold for increased cardiovascular risk due.

CONCLUSIONS

These results warrant for a great deal of effort from scientific societies to address the barriers that limit the routine use of the measurement of Lp(a) concentration and to recognise the importance of Lp(a) as a risk factor.

Lipoprotein (a), Inflammation, and Atherosclerosis

Growing evidence has shown that high levels of lipoprotein (a) (Lp(a)) and chronic inflammation may be responsible for the residual risk of cardiovascular events in patients managed with an optimal evidence-based approach. Clinical studies have demonstrated a correlation between higher Lp(a) levels and several atherosclerotic diseases including ischemic heart disease, stroke, and degenerative calcific aortic stenosis. The threshold value of Lp(a) serum concentrations associated with a significantly increased cardiovascular risk is >125 nmol/L (50 mg/dL). Current available lipid-lowering drugs have modest-to-no impact on Lp(a) levels. Chronic inflammation is a further condition potentially implicated in residual cardiovascular risk. Consistent evidence has shown an increased risk of cardiovascular events in patients with high sensitivity C reactive protein (>2 mg/dL), an inflammation biomarker. A number of anti-inflammatory drugs have been investigated in patients with or at risk of cardiovascular disease. Of these, canakinumab and colchicine have been found to be associated with cardiovascular risk reduction. Ongoing research aimed at improving risk stratification on the basis of Lp(a) and vessel inflammation assessment may help refine patient management. Furthermore, the identification of these conditions as cardiovascular risk factors has led to increased investigation into diagnostic and therapeutic strategies targeting them in order to reduce atherosclerotic cardiovascular disease burden.

The Oxidized Lipoproteins In Vivo: Its Diversity and Behavior in the Human Circulation

A high concentration of low-density lipoproteins (LDLs) in circulation has been well-known as a major risk factor for cardiovascular diseases. The presence of oxidized LDLs (oxLDLs) in atherosclerotic lesions and circulation was demonstrated using anti-oxLDL monoclonal antibodies. The so-called “oxLDL hypothesis”, as a mechanism for atherosclerosis development, has been attracting attention for decades. However, the oxLDL has been considered a hypothetical particle since the oxLDL present in vivo has not been fully characterized. Several chemically modified LDLs have been proposed to mimic oxLDLs. Some of the subfractions of LDL, especially Lp(a) and electronegative LDL, have been characterized as oxLDL candidates as oxidized phospholipids that stimulate vascular cells. Oxidized high-density lipoprotein (oxHDL) and oxLDL were discovered immunologically in vivo. Recently, an oxLDL-oxHDL complex was found in human plasma, suggesting the involvement of HDLs in the oxidative modification of lipoproteins in vivo. In this review, we summarize our understanding of oxidized lipoproteins and propose a novel standpoint to understand the oxidized lipoproteins present in vivo.

The Impact of the Blood Lipids Levels on Arterial Stiffness

Arterial stiffness is a recognized predictor of cardiovascular morbidity and death. It is an early indicator of arteriosclerosis and is influenced by numerous risk factors and biological processes. The lipid metabolism is crucial and standard blood lipids, non-conventional lipid markers and lipid ratios are associated with arterial stiffness. The objective of this review was to determine which lipid metabolism marker has a greater correlation with vascular aging and arterial stiffness. Triglycerides (TG) are the standard blood lipids that have the strongest associations with arterial stiffness, and are often linked to the early stages of cardiovascular diseases, particularly in patients with low LDL-C levels. Studies often show that lipid ratios perform better overall than any of the individual variables used alone. The relation between arterial stiffness and TG/HDL-C has the strongest evidence. It is the lipid profile of atherogenic dyslipidemia that is found in several chronic cardio-metabolic disorders, and is considered one of the main causes of lipid-dependent residual risk, regardless of LDL-C concentration. Recently, the use of alternative lipid parameters has also been increasing. Both non-HDL and ApoB are very well correlated with arterial stiffness. Remnant cholesterol is also a promising alternative lipid parameter. The findings of this review suggest that the main focus should be on blood lipids and arterial stiffness, especially in individuals with cardio-metabolic disorders and residual cardiovascular risk.

Hyperlipidemia and Cardiovascular Risk in Children and Adolescents

Atherosclerotic cardiovascular disease (ASCVD) represents the major cause of morbidity and mortality worldwide. The onset of the atherosclerosis process occurs during childhood and adolescence, subsequently leading to the onset of cardiovascular disease as young adults. Several cardiovascular risk factors can be identified in children and adolescents; however, hyperlipidemia, in conjunction with the global obesity epidemic, has emerged as the most prevalent, playing a key role in the development of ASCVD. Therefore, screening for hyperlipidemia is strongly recommended to detect high-risk children presenting with these disorders, as these patients deserve more intensive investigation and intervention. Treatment should be initiated as early as possible in order to reduce the risk of future ASCVD. In this review, we will discuss lipid metabolism and hyperlipidemia, focusing on correlations with cardiovascular risk and screening and therapeutic management to reduce or almost completely avoid the development of ASCVD.

Relationship of apolipoprotein(a) isoform size with clearance and production of lipoprotein(a) in a diverse cohort

Lipoprotein(a) [Lp(a)] has two main proteins, apoB100 and apo(a). High levels of Lp(a) confer an increased risk for atherosclerotic cardiovascular disease. Most people have two circulating isoforms of apo(a) differing in their molecular mass, determined by the number of Kringle IV Type 2 repeats. Previous studies report a strong inverse relationship between Lp(a) levels and apo(a) isoform sizes. The roles of Lp(a) production and fractional clearance and how ancestry affects this relationship remain incompletely defined. We therefore examined the relationships of apo(a) size with Lp(a) levels and both apo(a) fractional clearance rates (FCR) and production rates (PR) in 32 individuals not on lipid-lowering treatment. We determined plasma Lp(a) levels and apo(a) isoform sizes, and used the relative expression of the two isoforms to calculate a "weighted isoform size" (wIS). Stable isotope studies were performed, using D3-leucine, to determine the apo(a) FCR and PR. As expected, plasma Lp(a) concentrations were inversely correlated with wIS (R2 = 0.27; P = 0.002). The wIS had a modest positive correlation with apo(a) FCR (R2 = 0.10, P = 0.08), and a negative correlation with apo(a) PR (R2 = 0.11; P = 0.06). The relationship between wIS and PR became significant when we controlled for self-reported race and ethnicity (SRRE) (R2 = 0.24, P = 0.03); controlling for SRRE did not affect the relationship between wIS and FCR. Apo(a) wIS plays a role in both FCR and PR; however, adjusting for SRRE strengthens the correlation between wIS and PR, suggesting an effect of ancestry.

Consensus document for lipid profile determination and reporting in Spanish clinical laboratories. What parameters should be included in a basic lipid profile?

Cardiovascular diseases (CVD) continue to be the main cause of death in our country. Adequate control of lipid metabolism disorders is a key challenge in cardiovascular prevention that is far from being achieved in real clinical practice. There is a great heterogeneity in the reports of lipid metabolism from Spanish clinical laboratories, which may contribute to its poor control. For this reason, a working group of the main scientific societies involved in the care of patients at vascular risk, has prepared this document with a consensus proposal on the determination of the basic lipid profile in cardiovascular prevention, recommendations for its realization and unification of criteria to incorporate the lipid control goals appropriate to the vascular risk of the patients in the laboratory reports.

Australian Atherosclerosis Society Position Statement on Lipoprotein(a): Clinical and Implementation Recommendations

This position statement provides guidance to cardiologists and related specialists on the management of adult patients with elevated lipoprotein(a) [Lp(a)]. Elevated Lp(a) is an independent and causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve disease (CAVD). While circulating Lp(a) levels are largely determined by ancestry, they are also influenced by ethnicity, hormones, renal function, and acute inflammatory events, such that measurement should be done after accounting for these factors. Further, circulating Lp(a) concentrations should be estimated using an apo(a)-isoform independent assay that employs appropriate calibrators and reports the results in molar units (nmol/L). Selective screening strategies of high-risk patients are recommended, but universal screening of the population is currently not advised. Testing for elevated Lp(a) is recommended in all patients with premature ASCVD and those considered to be at intermediate-to-high risk of ASCVD. Elevated Lp(a) should be employed to assess and stratify risk and to enable a decision on initiation or intensification of preventative treatments, such as cholesterol lowering therapy. In adult patients with elevated Lp(a) at intermediate-to-high risk of ASCVD, absolute risk should be reduced by addressing all modifiable behavioural, lifestyle, psychosocial and clinical risk factors, including maximising cholesterol-lowering with statin and ezetimibe and, where appropriate, PCSK9 inhibitors. Apheresis should be considered in patients with progressive ASCVD. New ribonucleic acid (RNA)-based therapies which directly lower Lp(a) are undergoing clinical trials.

Extreme lipoprotein(a) in clinical practice: A cross sectional study

Introduction

Measurement of lipoprotein(a) [Lp(a)] is recommended once in a lifetime to identify individuals at high risk of atherosclerotic cardiovascular disease (ASCVD). We aimed to analyze the clinical features of patients with extreme Lp(a).

Methods

Cross-sectional, case-control study of a single healthcare organization between 2015 and 2021. Individuals with extreme Lp(a) > 430 nmol/L (53 of 3900 tested patients) were compared to age- and sex-matched controls with normal range Lp(a).

Results

Mean patient age was 58 ± 14 years (49% women). Myocardial infarction (47.2% vs. 18.9%), coronary artery disease (CAD) (62.3% vs. 28.3%), and peripheral artery disease (PAD) or stroke (22.6% vs. 11.3%) were more prevalent in patients with extreme than normal range Lp(a). The adjusted odds ratio [95% confidence interval (CI)] associated with extreme compared to normal range Lp(a) was 2.50 (1.20-5.21) for myocardial infarction, 2.20 (1.20-4.05) for CAD, and 2.75 (0.88-8.64) for PAD or stroke. A high-intensity statin plus ezetimibe combination was issued by 33% and 20% of CAD patients with extreme and normal range Lp(a), respectively. In patients with CAD, low density lipoprotein cholesterol (LDL-C) <55 mg/dL was achieved in 36% of those with extreme Lp(a) and 47% of those with normal range Lp(a).

Conclusions

Extremely elevated Lp(a) levels are associated with an approximately 2.5-fold increased risk of ASCVD compared with normal range Lp(a) levels. Although lipid-lowering treatment is more intense in CAD patients with extreme Lp(a), combination therapies are underused, and attainment rates of LDL-C goals are suboptimal.

Study of effect modifiers of genetically predicted CETP reduction

Genetic variants in drug targets can be used to predict the long-term, on-target effect of drugs. Here, we extend this principle to assess how sex and body mass index may modify the effect of genetically predicted lower CETP levels on biomarkers and cardiovascular outcomes. We found sex and body mass index (BMI) to be modifiers of the association between genetically predicted lower CETP and lipid biomarkers in UK Biobank participants. Female sex and lower BMI were associated with higher high-density lipoprotein cholesterol and lower low-density lipoprotein cholesterol for the same genetically predicted reduction in CETP concentration. We found that sex also modulated the effect of genetically lower CETP on cholesterol efflux capacity in samples from the Montreal Heart Institute Biobank. However, these modifying effects did not extend to sex differences in cardiovascular outcomes in our data. Our results provide insight into the clinical effects of CETP inhibitors in the presence of effect modification based on genetic data. The approach can support precision medicine applications and help assess the external validity of clinical trials.

Calcific aortic valve disease: mechanisms, prevention and treatment

Calcific aortic valve disease (CAVD) is the most common disorder affecting heart valves and is characterized by thickening, fibrosis and mineralization of the aortic valve leaflets. Analyses of surgically explanted aortic valve leaflets have shown that dystrophic mineralization and osteogenic transition of valve interstitial cells co-occur with neovascularization, microhaemorrhage and abnormal production of extracellular matrix. Age and congenital bicuspid aortic valve morphology are important and unalterable risk factors for CAVD, whereas additional risk is conferred by elevated blood pressure and plasma lipoprotein(a) levels and the presence of obesity and diabetes mellitus, which are modifiable factors. Genetic and molecular studies have identified that the NOTCH, WNT-β-catenin and myocardin signalling pathways are involved in the control and commitment of valvular cells to a fibrocalcific lineage. Complex interactions between valve endothelial and interstitial cells and immune cells promote the remodelling of aortic valve leaflets and the development of CAVD. Although no medical therapy is effective for reducing or preventing the progression of CAVD, studies have started to identify actionable targets.

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.

Apolipoprotein Proteomics for Residual Lipid-Related Risk in Coronary Heart Disease

BACKGROUND

Recognition of the importance of conventional lipid measures and the advent of novel lipid-lowering medications have prompted the need for more comprehensive lipid panels to guide use of emerging treatments for the prevention of coronary heart disease (CHD). This report assessed the relevance of 13 apolipoproteins measured using a single mass-spectrometry assay for risk of CHD in the PROCARDIS case-control study of CHD (941 cases/975 controls).

METHODS

The associations of apolipoproteins with CHD were assessed after adjustment for established risk factors and correction for statin use. Apolipoproteins were grouped into 4 lipid-related classes [lipoprotein(a), low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides] and their associations with CHD were adjusted for established CHD risk factors and conventional lipids. Analyses of these apolipoproteins in a subset of the ASCOT trial (Anglo-Scandinavian Cardiac Outcomes Trial) were used to assess their within-person variability and to estimate a correction for statin use. The findings in the PROCARDIS study were compared with those for incident cardiovascular disease in the Bruneck prospective study (n=688), including new measurements of Apo(a).

RESULTS

Triglyceride-carrying apolipoproteins (ApoC1, ApoC3, and ApoE) were most strongly associated with the risk of CHD (2- to 3-fold higher odds ratios for top versus bottom quintile) independent of conventional lipid measures. Likewise, ApoB was independently associated with a 2-fold higher odds ratios of CHD. Lipoprotein(a) was measured using peptides from the Apo(a)-kringle repeat and Apo(a)-constant regions, but neither of these associations differed from the association with conventionally measured lipoprotein(a). Among HDL-related apolipoproteins, ApoA4 and ApoM were inversely related to CHD, independent of conventional lipid measures. The disease associations with all apolipoproteins were directionally consistent in the PROCARDIS and Bruneck studies, with the exception of ApoM.

CONCLUSIONS

Apolipoproteins were associated with CHD independent of conventional risk factors and lipids, suggesting apolipoproteins could help to identify patients with residual lipid-related risk and guide personalized approaches to CHD risk reduction.

Documento de consenso para la determinación e informe del perfil lipídico en laboratorios clínicos españoles

Las enfermedades cardiovasculares (ECV) siguen siendo la principal causa de muerte en nuestro país. El control adecuado de las alteraciones del metabolismo lipídico es un reto clave en prevención cardiovascular que está lejos de alcanzarse en la práctica clínica real. Existe una gran heterogeneidad en los informes del metabolismo lipídico de los laboratorios clínicos españoles, lo que puede contribuir al mal control del mismo. Por ello, un grupo de trabajo de las principales sociedades científicas implicadas en la atención de los pacientes de riesgo vascular, hemos elaborado este documento con una propuesta básica de consenso sobre la determinación del perfil lipídico básico en prevención cardiovascular, recomendaciones para su realización y unificación de criterios para incorporar los objetivos de control lipídico adecuados al riesgo vascular de los pacientes en los informes de laboratorio. Palabras clave: consenso, panel de lípidos, enfermedades cardiovasculares, bioquímica, colesterol, lípidos, triglicéridos, lipoproteína (a).

Targeted proteomics using stable isotope labeled protein fragments enables precise and robust determination of total apolipoprotein(a) in human plasma

Lipoprotein(a), also known as Lp(a), is an LDL-like particle composed of apolipoprotein(a) (apo(a)) bound covalently to apolipoprotein B100. Plasma concentrations of Lp(a) are highly heritable and vary widely between individuals. Elevated plasma concentration of Lp(a) is considered as an independent, causal risk factor of cardiovascular disease (CVD). Targeted mass spectrometry (LC-SRM/MS) combined with stable isotope-labeled recombinant proteins provides robust and precise quantification of proteins in the blood, making LC-SRM/MS assays appealing for monitoring plasma proteins for clinical implications. This study presents a novel quantitative approach, based on proteotypic peptides, to determine the absolute concentration of apo(a) from two microliters of plasma and qualified according to guideline requirements for targeted proteomics assays. After optimization, assay parameters such as linearity, lower limits of quantification (LLOQ), intra-assay variability (CV: 4.7%) and inter-assay repeatability (CV: 7.8%) were determined and the LC-SRM/MS results were benchmarked against a commercially available immunoassay. In summary, the measurements of an apo(a) single copy specific peptide and a kringle 4 specific peptide allow for the determination of molar concentration and relative size of apo(a) in individuals.

Using genetic association data to guide drug discovery and development: Review of methods and applications

Evidence on the validity of drug targets from randomized trials is reliable but typically expensive and slow to obtain. In contrast, evidence from conventional observational epidemiological studies is less reliable because of the potential for bias from confounding and reverse causation. Mendelian randomization is a quasi-experimental approach analogous to a randomized trial that exploits naturally occurring randomization in the transmission of genetic variants. In Mendelian randomization, genetic variants that can be regarded as proxies for an intervention on the proposed drug target are leveraged as instrumental variables to investigate potential effects on biomarkers and disease outcomes in large-scale observational datasets. This approach can be implemented rapidly for a range of drug targets to provide evidence on their effects and thus inform on their priority for further investigation. In this review, we present statistical methods and their applications to showcase the diverse opportunities for applying Mendelian randomization in guiding clinical development efforts, thus enabling interventions to target the right mechanism in the right population group at the right time. These methods can inform investigators on the mechanisms underlying drug effects, their related biomarkers, implications for the timing of interventions, and the population subgroups that stand to gain the most benefit. Most methods can be implemented with publicly available data on summarized genetic associations with traits and diseases, meaning that the only major limitations to their usage are the availability of appropriately powered studies for the exposure and outcome and the existence of a suitable genetic proxy for the proposed intervention.

Monoclonal Antibodies, Gene Silencing and Gene Editing (CRISPR) Therapies for the Treatment of Hyperlipidemia-The Future Is Here

Hyperlipidemia is a significant risk factor for atherosclerotic cardiovascular disease. Undertreatment of elevated lipids persists despite existing therapies. Here, we provide an update on monoclonal antibodies, gene silencing therapies, and gene editing techniques for the management of hyperlipidemia. The current era of cutting-edge pharmaceuticals targeting low density lipoprotein cholesterol, PCSK9, lipoprotein (a), angiopoietin-like 3, and apolipoprotein C3 are reviewed. We outline what is known, studies in progress, and futuristic goals. This review of available and upcoming biotechnological lipid therapies is presented for clinicians managing patients with familial hyperlipidemia, statin intolerance, hypertriglyceridemia, or elevated lipoprotein (a) levels.

Atherogenic Dyslipidemias: Unmet Needs and the Therapeutic Potential of Emerging and Novel Approaches and Drugs

Innovative lipid-modifying agents are valuable resources to improve the control of atherogenic dyslipidemias and reduce the lipid-related residual cardiovascular risk of patients with intolerance or who are not fully responsive to a consolidated standard of care (statins plus ezetimibe). Moreover, some of the upcoming compounds potently affect lipid targets that are thus far considered "unmodifiable". The present paper is a viewpoint aimed at presenting the incremental metabolic and cardiovascular benefits of the emerging lipid-modulating agents and real-life barriers, hindering their prescription by physicians and their assumption by patients, which need to be worked out for a more diffuse and appropriate drug utilization.

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.

Protective effect of antihypertensive drugs on the risk of Parkinson's disease lacks causal evidence from mendelian randomization

Background: Evidence from observational studies concerning the causal role of blood pressure (BP) and antihypertensive medications (AHM) on Parkinson's disease (PD) remains inconclusive. A two-sample Mendelian randomization (MR) study was performed to evaluate the unconfounded association of genetic proxies for BP and first-line AHMs with PD. Methods: Instrumental variables (IV) from the genome-wide association study (GWAS) for BP traits were used to proxy systolic BP (SBP), diastolic BP, and pulse pressure. SBP-associated variants either located within encoding regions or associated with the expression of AHM targets were selected and then scaled to proxy therapeutic inhibition of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, calcium channel blockers, and thiazides. Positive control analyses on coronary heart disease (CHD) and stroke were conducted to validate the IV selection. Summary data from GWAS for PD risk and PD age at onset (AAO) were used as outcomes. Results: In positive control analyses, genetically determined BP traits and AHMs closely mimicked the observed causal effect on CHD and stroke, confirming the validity of IV selection methodology. In primary analyses, although genetic proxies identified by "encoding region-based method" for β-blockers were suggestively associated with a delayed PD AAO (Beta: 0.115; 95% CI: 0.021, 0.208; p = 1.63E-2; per 10-mmHg lower), sensitivity analyses failed to support this association. Additionally, MR analyses found little evidence that genetically predicted BP traits, overall AHM, or other AHMs affected PD risk or AAO. Conclusion: Our data suggest that BP and commonly prescribed AHMs may not have a prominent role in PD etiology.

Use of Lipoprotein(a) to improve diagnosis and management in clinical familial hypercholesterolemia

BACKGROUND AND AIMS

Lipoprotein(a) (Lp(a)) is an LDL-like particle whose plasma levels are largely genetically determined. The impact of measuring Lp(a) in patients with clinical familial hypercholesterolemia (FH) referred for genetic testing is largely unknown. We set out to evaluate the contribution of (genetically estimated) Lp(a) in a large nation-wide referral population of clinical FH.

METHODS

In 1504 patients referred for FH genotyping, we used an LPA genetic instrument (rs10455872 and rs3798220) as a proxy for plasma Lp(a) levels. The genetic Lp(a) proxy was used to correct LDL-cholesterol and reclassify patients with clinical FH based on Dutch Lipid Criteria Network (DLCN) scoring. Finally, we used estimated Lp(a) levels to reclassify ASCVD risk using the SCORE and SMART risk scores.

RESULTS

LPA SNPs were more prevalent among mutation-negative compared with mutation-positive patients (296/1280 (23.1%) vs 35/224 (15.6%), p = 0.016). Among patients with genetically defined high Lp(a) levels, 9% were reclassified to the DLCN category 'unlikely FH' using Lp(a)-corrected LDL-cholesterol (LDL-Ccor) and all but one of these patients indeed carried no FH variant. Furthermore, elevated Lp(a) reclassified predicted ASCVD risk into a higher category in up to 18% of patients.

CONCLUSIONS

In patients referred for FH molecular testing, we show that taking into account (genetically estimated) Lp(a) levels not only results in reclassification of probability of genetic FH, but also has an impact on individual cardiovascular risk evaluation. However, to avoid missing the diagnosis of an FH variant, clear thresholds for the use of Lp(a)-cholesterol adjusted LDL-cholesterol levels in patients referred for genetic testing of FH must be established.

Residual Atherosclerotic Cardiovascular Disease Risk: Focus on Non-High-Density Lipoprotein Cholesterol

Cardiovascular disease (CVD) caused by atherosclerosis is the leading cause of death worldwide. The level of low-density lipoprotein cholesterol (LDL-C), considered as the initiator of atherosclerosis, is the most widely used predictor for CVD risk and LDL-C has been the primary target for lipid-lowering therapies. However, residual CVD risk remains high even with very low levels of LDL-C. This residual CVD risk may be due to remnant cholesterol, high triglyceride levels, and low high-density lipoprotein cholesterol (HDL-C). Non-high density lipoprotein cholesterol (non-HDL-C), which is calculated as total cholesterol minus HDL-C (and represents the cholesterol content of all atherogenic apolipoprotein B-containing lipoproteins), has emerged as a better risk predictor for CVD than LDL-C and an alternative target for CVD risk reduction. Major international guidelines recommend evaluating non-HDL-C as part of atherosclerotic CVD risk assessment, especially in people with high triglycerides, diabetes, obesity, or very low LDL-C. A non-HDL-C target of <130 mg/dL (3.4 mmol/L) has been recommended for patients at very high risk, which is 30 mg/dL (0.8 mmol/L) higher than the corresponding LDL-C target goal. Non-HDL-C lowering approaches include reducing LDL-C and triglyceride levels, increasing HDL-C, or targeting multiple risk factors simultaneously. However, despite the growing evidence for the role of non-HDL-C in residual CVD risk, and recommendations for its assessment in major guidelines, non-HDL-C testing is not routinely done in clinical practice. Thus, there is a need for increased awareness of the need for non-HDL-C testing for ascertaining CVD risk and concomitant prevention of CVD.

Targeted Treatment against Lipoprotein (a): The Coming Breakthrough in Lipid Lowering Therapy

Atherosclerotic cardiovascular diseases (ASCVD) are a very important cause of premature death. The most important risk factor for ASCVD is lipid disorders. The incidence of lipid disorders and ASCVD is constantly increasing, which means that new methods of prevention and treatment of these diseases are still being searched for. In the management of patients with lipid disorders, the primary goal of therapy is to lower the serum LDL-C concentration. Despite the available effective lipid-lowering therapies, the risk of ASCVD is still increased in some patients. A high level of serum lipoprotein (a) (Lp(a)) is a risk factor for ASCVD independent of serum LDL-C concentration. About 20% of Europeans have elevated serum Lp(a) levels, requiring treatment to reduce serum Lp(a) concentrations in addition to LDL-C. Currently available lipid lowering drugs do not sufficiently reduce serum Lp(a) levels. Hence, drugs based on RNA technology, such as pelacarsen, olpasiran, SLN360 and LY3819469, are undergoing clinical trials. These drugs are very effective in lowering the serum Lp(a) concentration and have a satisfactory safety profile, which means that in the near future they will fill an important gap in the armamentarium of lipid-lowering drugs.

Lipoprotein(a): a risk factor for atherosclerosis and an emerging therapeutic target

Lipoprotein(a) (Lp(a)) is a complex circulating lipoprotein, and increasing evidence has demonstrated its role as a risk factor for atherosclerotic cardiovascular disease (ASCVD) and as a possible therapeutic target. Lp(a) atherogenic effects are attributed to several potential mechanisms in addition to cholesterol accumulation in the arterial wall, including proinflammatory effects mainly mediated by oxidised phospholipids. Several studies have found a causal and independent relationship between Lp(a) levels and cardiovascular risk. Furthermore, several studies also suggest a causal association between Lp(a) levels and calcific aortic valve stenosis. Available lipid-lowering agents have at best moderate impact on Lp(a) levels. Among available therapies, antibody proprotein convertase subtilisin/kexin type 9 inhibitors are the most effective in reducing Lp(a). Potent Lp(a)-lowering treatments that target LPA expression are under development. Lp(a) level measurement poses some challenges due to the absence of a definitive reference method and the reporting of Lp(a) values as molar (nanomoles per litre (nmol/L)) or mass concentrations (milligrams per decilitre (mg/dL)) by different assays. Currently, Lp(a) measurement is recommended to refine cardiovascular risk in specific clinical settings, that is, in individuals with a family history of premature ASCVD, in patients with ASCVD not explained by standard risk factors or in those with recurrent events despite optimal management of traditional risk factors. Patients with high Lp(a) levels should be managed with more intensive approaches to treat other modifiable cardiovascular risk factors. Overall, this review focuses on Lp(a) as an ASCVD risk factor and therapeutic target. Furthermore, it reports practical recommendations for Lp(a) measurement and interpretation and updated evidence on Lp(a)-lowering approaches.

Circulating lipoprotein(a) levels and health outcomes: Phenome-wide Mendelian randomization and disease-trajectory analyses

BACKGROUND

Lipoprotein(a) [Lp(a)] is a risk factor for atherosclerotic and valvular diseases, but its possible role in other diseases has not yet been established. We conducted phenome-wide Mendelian randomization and disease-trajectory analyses to assess any associations of circulating Lp(a) levels with a broad range of diseases.

METHODS

A weighted polygenic risk score was constructed using independent genetic variants in the LPA gene and with an established effect on Lp(a) levels. The PheWAS analysis included 1081 phenotype outcomes ascertained among 385,917 White participants of the UK Biobank. Novel findings were investigated in MR analysis using data from the FinnGen consortium. Disease-trajectory and comorbidity analyses were further conducted to explore the sequential patterns of multiple morbidities related to high circulating Lp(a) levels.

RESULTS

PheWAS revealed statistically significant associations of higher circulating Lp(a) levels with increased risk of a large number of circulatory system diseases (including various cardiac diseases, peripheral vascular disease, hypertension, and valvular and cerebrovascular diseases) as well as some endocrine/metabolic diseases (including hyperlipidemia, hypercholesterolemia, disorders of lipoid metabolism, and type 2 diabetes), genitourinary system diseases (renal failure), and hematologic diseases (including different types of anemia). Two-sample MR analysis supported the association between Lp(a) and risk of anemia, showed a suggestive association with type 2 diabetes, but found no association with renal failure. Disease-trajectory and comorbidity analyses identified 3 major sequential patterns of multiple morbidities, mainly in the cardiovascular, metabolic, and mental disorders, related to high circulating Lp(a) levels.

CONCLUSIONS

Genetically predicted higher circulating Lp(a) levels were associated with increased risk of many circulatory system diseases and anemia. Additionally, this study identified three major sequential patterns of multiple morbidities related to high Lp(a).

Recent lipoprotein(a) trials

PURPOSE OF REVIEW

Lipoprotein(a) (Lp(a)) is a genetically determined independent risk factor for cardiovascular disease and calcific aortic stenosis; thus, serum levels are minimally affected by conventional treatments for hypercholesterolemia and hypertriglyceridemia. New RNA therapies directly targeting Lp(a) have demonstrated efficacy in decreasing serum levels. Several recent trials have demonstrated efficacy and safety of these RNA therapeutics.

RECENT FINDINGS

Single-stranded antisense oligonucleotides (ASOs) and small interfering RNA (siRNA) are two classes of RNA-targeted therapeutics that specifically target the LPA gene, which encodes for apolipoprotein(a), a dominant and rate-limiting component in the hepatic synthesis of Lp(a) particle. Pelacarsen (ASO), olpasiran (siRNA) and SLN360 (siRNA) are novel drugs that have demonstrated efficacy in lowering Lp(a) levels and excellent safety profiles.

SUMMARY

Lp(a) is an independent risk factor for cardiovascular disease. RNA-directed therapies, pelacarsen, olpasiran and SLN360, have shown efficacy in dramatically lowering serum Lp(a) levels. Outcomes data will be the next frontier of Lp(a) trials.

Association of Lipoprotein(a) Levels With Incidence of Major Adverse Limb Events

IMPORTANCE

High lipoprotein(a) (Lp[a]) levels are involved in the development of cardiovascular events, particularly in myocardial infarction, stroke, and peripheral artery disease. Studies assessing the Lp(a) levels associated with adverse lower-limb events are lacking.

OBJECTIVE

To assess the association between Lp(a) levels and incidence of major adverse limb events in unselected hospitalized patients.

DESIGN, SETTING, AND PARTICIPANTS

This large retrospective monocentric cohort study was conducted from January 1, 2000, to December 31, 2020. Data were derived from the clinical information system of the Hôpital Européen Georges-Pompidou, a Paris-based university hospital. Patients who underwent at least 1 Lp(a) measurement at the center during the study period were included. Patients who had no follow-up data or who had the first Lp(a) measurement after the study outcome had occurred were excluded. Data analyses were performed from May 2021 to January 2022.

MAIN OUTCOMES AND MEASURES

The primary outcome was the first inpatient major adverse limb event, defined as a major amputation, peripheral endovascular revascularization, or peripheral surgical revascularization, during follow-up. Secondary outcomes included individual components of the primary outcome. Lipoprotein(a) levels were categorized as follows: normal (<50 mg/dL), high (50 to <134 mg/dL), and very high (≥134 mg/dL); to convert Lp(a) values to milligrams per liter, multiply by 0.1.

RESULTS

A total of 16 513 patients (median [IQR] age, 58.2 [49.0-66.7] years; 9774 men [59.2%]) were included in the cohort. The median (IQR) Lp(a) level was 24 (10.0-60.0) mg/dL. The 1-year incidence of major adverse limb event was 2.44% in the overall population and 4.54% among patients with very high Lp(a) levels. High (adjusted accelerated failure time [AFT] exponential estimate: 0.43; 95% CI, 0.24-0.78; Benjamini-Hochberg-corrected P = .01) and very high (adjusted AFT exponential estimate: 0.17; 95% CI, 0.07-0.40; Benjamini-Hochberg-corrected P < .001) Lp(a) levels were independently associated with an increased risk of major adverse limb event.

CONCLUSIONS AND RELEVANCE

Results of this study showed that higher Lp(a) levels were independently associated with an increased risk of a major adverse limb event in hospitalized patients. The Lp(a) measurement needs to be taken into account to improve lower-limb vascular risk assessment.

New Horizons: Revival of Lipoprotein (a) as a Risk Factor for Cardiovascular Disease

The status of lipoprotein (a) [Lp(a)] as a cardiovascular risk factor has been resurrected by advances in genetics. Mendelian randomization studies show a causal link of Lp(a) with coronary artery disease (CAD), peripheral artery disease (PAD), and calcific aortic valve stenosis (CAVS). The genetics of Lp(a) is complex and extends beyond the kringle-IV type 2, as it is also dependent on ancestry. The plasma concentration of Lp(a) is determined by the hepatic production of apolipoprotein(a) [apo(a)] component of Lp(a), supporting the use of nucleic acids that inhibit the messenger RNA (mRNA) gene transcript for apo(a). Analytical barriers to measurement of Lp(a) are being addressed using isoform independent assays and a traceable standard. The association of Lp(a) and atherosclerotic cardiovascular disease is higher for myocardial infarction than PAD and CAVS. Increased risk of type 2 diabetes mellitus associated with low Lp(a) levels is perplexing and requires further investigation. The greatest advancement in Lp(a)-lowering therapies is based on using RNA therapeutics that are now being investigated in clinical trials. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition lowers Lp(a) modestly, but whether cardiovascular benefit is independent of low-density lipoprotein lowering remains unclear. Opportunistic and selective testing for Lp(a) is supported by moderate evidence, with the case for universal screening premature. Modification of behavioral and clinical risk factors may be targeted to mitigate Lp(a)-mediated risk of cardiovascular disease. Clinical practice guidelines have been developed to address gaps in care of high Lp(a), but full implementation awaits the findings of clinical outcome trials using RNA-directed therapies currently underway.

Small Interfering RNA to Reduce Lipoprotein(a) in Cardiovascular Disease

BACKGROUND

Lipoprotein(a) is a presumed risk factor for atherosclerotic cardiovascular disease. Olpasiran is a small interfering RNA that reduces lipoprotein(a) synthesis in the liver.

METHODS

We conducted a randomized, double-blind, placebo-controlled, dose-finding trial involving patients with established atherosclerotic cardiovascular disease and a lipoprotein(a) concentration of more than 150 nmol per liter. Patients were randomly assigned to receive one of four doses of olpasiran (10 mg every 12 weeks, 75 mg every 12 weeks, 225 mg every 12 weeks, or 225 mg every 24 weeks) or matching placebo, administered subcutaneously. The primary end point was the percent change in the lipoprotein(a) concentration from baseline to week 36 (reported as the placebo-adjusted mean percent change). Safety was also assessed.

RESULTS

Among the 281 enrolled patients, the median concentration of lipoprotein(a) at baseline was 260.3 nmol per liter, and the median concentration of low-density lipoprotein cholesterol was 67.5 mg per deciliter. At baseline, 88% of the patients were taking statin therapy, 52% were taking ezetimibe, and 23% were taking a proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitor. At 36 weeks, the lipoprotein(a) concentration had increased by a mean of 3.6% in the placebo group, whereas olpasiran therapy had significantly and substantially reduced the lipoprotein(a) concentration in a dose-dependent manner, resulting in placebo-adjusted mean percent changes of -70.5% with the 10-mg dose, -97.4% with the 75-mg dose, -101.1% with the 225-mg dose administered every 12 weeks, and -100.5% with the 225-mg dose administered every 24 weeks (P&lt;0.001 for all comparisons with baseline). The overall incidence of adverse events was similar across the trial groups. The most common olpasiran-related adverse events were injection-site reactions, primarily pain.

CONCLUSIONS

Olpasiran therapy significantly reduced lipoprotein(a) concentrations in patients with established atherosclerotic cardiovascular disease. Longer and larger trials will be necessary to determine the effect of olpasiran therapy on cardiovascular disease. (Funded by Amgen; OCEAN[a]-DOSE ClinicalTrials.gov number, NCT04270760.).

Mild-to-Moderate Kidney Dysfunction and Cardiovascular Disease: Observational and Mendelian Randomization Analyses

BACKGROUND

End-stage renal disease is associated with a high risk of cardiovascular events. It is unknown, however, whether mild-to-moderate kidney dysfunction is causally related to coronary heart disease (CHD) and stroke.

METHODS

Observational analyses were conducted using individual-level data from 4 population data sources (Emerging Risk Factors Collaboration, EPIC-CVD [European Prospective Investigation into Cancer and Nutrition-Cardiovascular Disease Study], Million Veteran Program, and UK Biobank), comprising 648 135 participants with no history of cardiovascular disease or diabetes at baseline, yielding 42 858 and 15 693 incident CHD and stroke events, respectively, during 6.8 million person-years of follow-up. Using a genetic risk score of 218 variants for estimated glomerular filtration rate (eGFR), we conducted Mendelian randomization analyses involving 413 718 participants (25 917 CHD and 8622 strokes) in EPIC-CVD, Million Veteran Program, and UK Biobank.

RESULTS

There were U-shaped observational associations of creatinine-based eGFR with CHD and stroke, with higher risk in participants with eGFR values <60 or >105 mL·min-1·1.73 m-2, compared with those with eGFR between 60 and 105 mL·min-1·1.73 m-2. Mendelian randomization analyses for CHD showed an association among participants with eGFR <60 mL·min-1·1.73 m-2, with a 14% (95% CI, 3%-27%) higher CHD risk per 5 mL·min-1·1.73 m-2 lower genetically predicted eGFR, but not for those with eGFR >105 mL·min-1·1.73 m-2. Results were not materially different after adjustment for factors associated with the eGFR genetic risk score, such as lipoprotein(a), triglycerides, hemoglobin A1c, and blood pressure. Mendelian randomization results for stroke were nonsignificant but broadly similar to those for CHD.

CONCLUSIONS

In people without manifest cardiovascular disease or diabetes, mild-to-moderate kidney dysfunction is causally related to risk of CHD, highlighting the potential value of preventive approaches that preserve and modulate kidney function.

Genome-wide association and multi-trait analyses characterize the common genetic architecture of heart failure

Heart failure is a leading cause of cardiovascular morbidity and mortality. However, the contribution of common genetic variation to heart failure risk has not been fully elucidated, particularly in comparison to other common cardiometabolic traits. We report a multi-ancestry genome-wide association study meta-analysis of all-cause heart failure including up to 115,150 cases and 1,550,331 controls of diverse genetic ancestry, identifying 47 risk loci. We also perform multivariate genome-wide association studies that integrate heart failure with related cardiac magnetic resonance imaging endophenotypes, identifying 61 risk loci. Gene-prioritization analyses including colocalization and transcriptome-wide association studies identify known and previously unreported candidate cardiomyopathy genes and cellular processes, which we validate in gene-expression profiling of failing and healthy human hearts. Colocalization, gene expression profiling, and Mendelian randomization provide convergent evidence for the roles of BCKDHA and circulating branch-chain amino acids in heart failure and cardiac structure. Finally, proteome-wide Mendelian randomization identifies 9 circulating proteins associated with heart failure or quantitative imaging traits. These analyses highlight similarities and differences among heart failure and associated cardiovascular imaging endophenotypes, implicate common genetic variation in the pathogenesis of heart failure, and identify circulating proteins that may represent cardiomyopathy treatment targets.

Associations of lipid measures with total occlusion in patients with established coronary artery disease: a cross-sectional study

Background

Total occlusion is the most severe coronary lesion, indicating heavy ischemic burden and poor prognosis. The lipid profile is central to the development of atherosclerotic coronary lesions. Evidence on the optimal lipid measure to be monitored and managed in patients with established coronary artery disease (CAD) is inconclusive.

Methods

Total cholesterol (TC), total triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), nonhigh-density lipoprotein cholesterol (non-HDL-c), lipoprotein (a) [Lp(a)], apolipoprotein B (apoB), non-HDL-c/HDL-c, and apoB/apoA-1 were analyzed in quintiles and as continuous variables. The associations of lipid measures with total occlusion were tested using logistic regression models, visualized with restricted cubic splines, and compared by areas under the receiver operating characteristic curves (AUROC). Discordance analysis was performed when apoB/apoA-1 and non-HDL-c/HDL-c were not in concordance.

Results

The prospective cohort study included 10,003 patients (mean age: 58 years; women: 22.96%), with 1879 patients having total occlusion. The risks of total occlusion significantly increased with quintiles of Lp(a), non-HDL-c/HDL-c, and apoB/apoA-1 (all p for trend < 0.001). TG had no association with total occlusion. Restricted cubic splines indicate significant positive linear relations between the two ratios and total occlusion [odds ratio per 1-standard deviation increase (95% confidence interval): non-HDL-c/HDL-c: 1.135 (1.095–1.176), p < 0.001; apoB/apoA-1: 2.590 (2.049–3.274), p < 0.001]. The AUROCs of apoB/apoA-1 and non-HDL-c/HDL-c were significantly greater than those of single lipid measures. Elevation in the apoB/apoA-1 tertile significantly increased the risk of total occlusion at a given non-HDL-c/HDL-c tertile but not vice versa.

Conclusion

ApoB/apoA-1 confers better predictive power for total occlusion than non-HDL-c/HDL-c and single lipid measures in established CAD patients.

Lipoprotein(a) and residual vascular risk in statin-treated patients with first acute ischemic stroke: A prospective cohort study

OBJECTIVES

Statins either barely affect or increase lipoprotein(a) [Lp(a)] levels. This study aimed to explore the factors correlated to the change of Lp(a) levels as well as the relationship between Lp(a) and the recurrent vascular events in statin-treated patients with first acute ischemic stroke (AIS).

METHODS

Patients who were admitted to the hospital with first AIS from October 2018 to September 2020 were eligible for inclusion. Correlation between the change of Lp(a) levels and potential influencing factors was assessed by linear regression analysis. Cox proportional regression models were used to estimate the association between Lp(a) and recurrent vascular events including AIS, transient ischemic attack, myocardial infarction and coronary revascularization.

RESULTS

In total, 303 patients, 69.6% males with mean age 64.26 ± 11.38 years, completed the follow-up. During the follow-up period, Lp(a) levels increased in 50.5% of statin-treated patients and the mean percent change of Lp(a) levels were 14.48% (95% CI 6.35-22.61%). Creatinine (β = 0.152, 95% CI 0.125-0.791, P = 0.007) and aspartate aminotransferase (AST) (β = 0.160, 95% CI 0.175-0.949, P = 0.005) were positively associated with the percent change of Lp(a) levels. During a median follow-up of 26 months, 66 (21.8%) patients had a recurrent vascular event. The median time period between AIS onset and vascular events recurrence was 9.5 months (IQR 2.0-16.3 months). The on-statin Lp(a) level ≥70 mg/dL (HR 2.539, 95% CI 1.076-5.990, P = 0.033) and the change of Lp(a) levels (HR 1.003, 95% CI 1.000-1.005, P = 0.033) were associated with the recurrent vascular events in statin-treated patients with first AIS. Furthermore, the on-statin Lp(a) levels ≥70 mg/dL (HR 3.612, 95% CI 1.018-12.815, P = 0.047) increased the risk of recurrent vascular events in patients with low-density lipoprotein cholesterol (LDL-C) levels < 1.8 mmol/L.

CONCLUSIONS

Lp(a) levels increased in half of statin-treated patients with first AIS. Creatinine and AST were positively associated with the percent change of Lp(a) levels. Lp(a) is a determinant of residual vascular risk and the change of Lp(a) is positively associated with the risk of recurrent vascular events in these patients.

Genetic proxies for PCSK9 inhibition associate with lipoprotein(a): Effects on coronary artery disease and ischemic stroke

BACKGROUND AND AIMS

Post hoc analyses of clinical trials show that PCSK9 inhibitors might lower lipoprotein(a), but whether this effect contributes to reductions in cardiovascular risk remains unknown. We aimed to assess whether genetically proxied PCSK9 inhibition influences lipoprotein(a) (Lp(a)), and whether any such effect could mediate its effects on coronary artery disease (CAD) and ischemic stroke (IS).

METHODS

To explore associations between the genetic proxies for PCSK9 inhibitors and Lp(a) levels, we used UK Biobank data (310,020 individuals). We identified 10 variants in the PCSK9 gene associated with lower PCSK9 and LDL-C levels as proxies for PCSK9 inhibition. We explored the effects of genetically proxied PCSK9 inhibition on Lp(a) levels, as well as on odds of CAD (60,801 cases, 184,305 controls) and IS (60,341 cases, 454,450 controls) in two-sample Mendelian randomization analyses. In mediation analyses, we assessed the effects of genetically proxied PCSK9 inhibition on CAD and IS mediated through reductions in Lp(a) levels.

RESULTS

Genetically proxied PCSK9 inhibition (1-SD decrement in PCSK9 concentration; corresponding to 20.6 mg/dl decrement in LDL-C levels) was associated with a 4% decrease in log-Lp(a) levels (beta: -0.038, 95%CI: -0.053 to -0.023). We estimated a 0.8% reduction in the odds for CAD (OR: 0.992, 95%CI: 0.989-0.995) and a 0.5% reduction in the odds for atherosclerotic IS (OR: 0.995, 95%CI: 0.992-0.998) due to reductions in Lp(a) levels through genetically proxied PCSK9 inhibition, corresponding to 3.8% and 3.2% of the total effects, respectively.

CONCLUSIONS

Genetic proxies for PCSK9 inhibition are associated with lower Lp(a) levels. However, Lp(a) lowering explains only a small proportion of the total effects of genetic proxies for PCSK9 inhibitors on risk of CAD and IS.

Lipoprotein(a) and Cardiovascular Disease in Chinese Population: A Beijing Heart Society Expert Scientific Statement

Elevated concentration of lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic cardiovascular disease, including coronary artery disease, stroke, peripheral artery disease, and so on. Emerging data suggest that Lp(a) contributes to the increased risk for cardiovascular events even in the setting of effective reduction of plasma low-density lipoprotein cholesterol. Nevertheless, puzzling issues exist covering potential genetic factors, Lp(a) assay, possible individuals for analysis, a cutoff point of increased risk, and clinical interventions. In the Chinese population, Lp(a) exhibited a distinctive prevalence and regulated various cardiovascular diseases in specific ways. Hence, it is valuable to clarify the role of Lp(a) in cardiovascular diseases and explore prevention and control measures for the increase in Lp(a) prevalence in the Chinese population. This Beijing Heart Society experts' scientific statement will present the detailed knowledge concerning Lp(a)-related studies combined with Chinese population observations to provide the key points of reference.

The relationship between lipoprotein(a) and risk of cardiovascular disease: a Mendelian randomization analysis

BACKGROUND

Lipoprotein(a) [Lp(a)] is one of the residual risk factors for cardiovascular disease (CVD) in the setting of optimal low-density lipoprotein cholesterol (LDL-C). The association between Lp(a) and CVD is still in the exploratory phase, with few studies indicating a causal connection between Lp(a) and various CVD.

METHODS

Lp(a) (n = 377,590) was a genome-wide association study (GWAS) based on European populations from Neale Lab. Large GWAS datasets for CVD, including aortic aneurysm(AA) (n = 209,366), atrial fibrillation(AF) (n = 1,030,836), coronary heart disease(CHD) (n = 361,194), secondary hypertension(HBP) (n = 164,147), heart failure(HF) (n = 208,178), ischemic stroke (IS) (n = 218,792), large artery atherosclerosis stroke(ISL) (n = 150, 765), small vessel stroke(ISS) (n = 198,048), lacunar stroke(LIS) (n = 225,419), and pulmonary embolism(PE) (n = 218,413) were also based on European populations. We performed separate univariate two-sample Mendelian randomization (MR) analysis for Lp(a) and CVD as described above. We evaluated this connection mainly using the random-effects inverse variance weighted technique(IVW1) with a 95% confidence interval (CI) for the odds ratio (OR). This was supplemented by MR-Egger, weighted median, maximum likelihood, penalized weighted median, and fixed-effects inverse variance weighted methods. MR-PRESSO offers another means of statistical detection.

RESULTS

Our two-sample MR, which was predominately based on IVW1, revealed a causal relationship between Lp(a) and AA (OR = 1.005, 95%CI: 1.001-1.010, P = 0.009), CHD (OR = 1.003, 95%CI 1.001-1.004, P = 0.010), and ISL (OR = 1.003, 9 5%CI 1.002-1.004, P = 9.50E-11), in addition, there is no causal association with AF, HBP, HF, IS, ISS, LIS, or PE. Similar conclusions were reached by the MR-PRESSO method.

CONCLUSION

This MR study suggested a causal relationship between Lp(a) and CHD, AA, and ISL, but not associated with AF, HF, IS, LIS, ISS, HBP, or PE. Our work further verifies the association between Lp(a) and various CVD, resulting in improved Lp(a) management and a reduction in the prevalence of CVD.

Independent association of Lp(a) with platelet reactivity in subjects without statins or antiplatelet agents

The physiological effect of Lp(a) on platelet activity is unclear. Previous studies explored the relationship between Lp(a) and platelet aggregation in patients taking statins and antiplatelet agents, but few was conducted in individuals without the bias of those drugs that either influence Lp(a) or platelet activity. The aim of this study was to assess the relationship between Lp(a) levels and platelet aggregation in subjects not taking statins or antiplatelet drugs. A hospital-based cross-sectional study was conducted to investigate the independent contribution of Lp(a) to platelet activity by controlling the effects of potential confounding factors including lipoprotein-associated phospholipase A2 [Lp-PLA2]. Blood samples were collected from 92 subjects without statins or antiplatelet agents from the Second Xiangya Hospital. The univariate correlation analysis showed a significant correlation between AA-induced average aggregation rate [AAR] and ApoB (r = 0.324, P = 0.002), ApoA1 (r = 0.252, P = 0.015), Lp(a) (r = 0.370, P < 0.001), Lp-PLA2 (r = 0.233, P = 0.025) and platelet counts [PLT] (r = 0.389, P < 0.001). Multivariate regression analysis suggested that Lp(a) contributed independently to AA-induced average aggregation rate (β = 0.023, P = 0.027) after controlling for the effects of ApoB, Lp-PLA2 and platelet counts. Lp(a) is positively associated with platelet aggregation independent of Lp-PLA2, which may partly account for the atherothrombotic effect of Lp(a).

Lp(a): a New Pathway to Target?

Purpose of Review

Over the past decades, genetic and observational evidence has positioned lipoprotein(a) as novel important and independent risk factor for cardiovascular disease (ASCVD) and aortic valve stenosis.

Recent Findings

As Lp(a) levels are determined genetically, lifestyle interventions have no effect on Lp(a)-mediated ASCVD risk. While traditional low-density lipoprotein cholesterol (LDL-C) can now be effectively lowered in the vast majority of patients, current lipid lowering therapies have no clinically relevant Lp(a) lowering effect.

Summary

There are multiple Lp(a)-directed therapies in clinical development targeting LPA mRNA that have shown to lower Lp(a) plasma levels for up to 90%: pelacarsen, olpasiran, and SLN360. Pelacarsen is currently investigated in a phase 3 cardiovascular outcome trial expected to finish in 2024, while olpasiran is about to proceed to phase 3 and SLN360’s phase 1 outcomes were recently published. If proven efficacious, Lp(a) will soon become the next pathway to target in ASCVD risk management.

The Inherited Hypercholesterolemias

Inherited hypercholesterolemias include monogenic and polygenic disorders, which can be very rare (eg, cerebrotendinous xanthomatosis (CTX)) or relatively common (eg, familial combined hyperlipidemia [FCH]). In this review, we discuss familial hypercholesterolemia (FH), FH-mimics (eg, polygenic hypercholesterolemia [PH], FCH, sitosterolemia), and other inherited forms of hypercholesterolemia (eg, hyper-lipoprotein(a) levels [hyper-Lp(a)]). The prevalence, genetics, and management of inherited hypercholesterolemias are described and selected guidelines summarized.

Study design and rationale for the Olpasiran trials of Cardiovascular Events And lipoproteiN(a) reduction-DOSE finding study (OCEAN(a)-DOSE)

BACKGROUND

Data support lipoprotein(a) (Lp[Lp(a)]) being a risk factor for atherosclerotic cardiovascular disease (ASCVD). Olpasiran is a small interfering RNA molecule that markedly reduces Lp(a) production in hepatocytes.

STUDY DESIGN

The Olpasiran trials of Cardiovascular Events And lipoproteiN(a) reduction-DOSE finding study is a multicenter, randomized, double-blind, placebo-controlled dose-finding study in 281 subjects with established ASCVD and Lp(a) > 150 nmol/L. Patients were randomly allocated to one of 4 active subcutaneous doses of olpasiran (10 mg q12 weeks, 75 mg q12 weeks, 225 mg q 12 weeks, or 225 mg q24 weeks) or matched placebo. The primary objective is to evaluate the effects of olpasiran dosed every 12 weeks compared with placebo on the percent change in Lp(a) from baseline at 36 weeks. Enrollment is now complete and follow-up is ongoing.

CONCLUSIONS

OCEAN(a)-DOSE trial is assessing the Lp(a)-lowering efficacy and safety of olpasiran. These data will be used to determine optimal dosing and design for a cardiovascular outcomes trial.

New and Emerging Therapies for Dyslipidemia

Atherosclerotic cardiovascular disease (ASCVD) continues to represent a growing global health challenge. Despite guideline-recommended treatment of ASCVD risk, including antihypertensive, high-intensity statin therapy, and antiaggregant agents, high-risk patients, especially those with established ASCVD and patients with type 2 diabetes, continue to experience cardiovascular events. Recent years have brought significant developments in lipid and atherosclerosis research. Several lipid drugs owe their existence, in part, to human genetic evidence. Here, the authors briefly review the mechanisms, the effect on lipid parameters, and safety profiles of some of the most promising new lipid-lowering approaches that will be soon available in our daily clinical practice.

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.

Ancestry, Lipoprotein(a), and Cardiovascular Risk Thresholds: JACC Review Topic of the Week

This study reviews ancestral differences in the genetics of the LPA gene, risk categories of elevated lipoprotein(a) [Lp(a)] as defined by guidelines, ancestry-specific Lp(a) risk, absolute and proportional risk, predictive value of risk thresholds among different ancestries, and differences between laboratory vs clinical accuracy in Lp(a) assays. For clinical decision-making, the preponderance of evidence suggests that the predictive value of Lp(a) does not vary sufficiently to mandate the use of ancestry-specific risk thresholds. This paper interprets the literature on Lp(a) and ancestral risk to support: 1) clinicians on understanding cardiovascular disease risk in different ancestral groups; 2) trialists for the design of clinical trials to ensure adequate ancestral diversity to support broad conclusions of drug effects; 3) regulators in the evaluation of the design and interpretation of results of Lp(a)-lowering trials with different Lp(a) inclusion thresholds; and 4) clinical laboratories to measure Lp(a) by assays that discriminate risk thresholds appropriately.

Causal associations between gut microbiome and cardiovascular disease: A Mendelian randomization study

Background

Observational studies have shown gut microbiomes were associated with cardiovascular diseases (CVDs), but their roles remain controversial, and these associations have not yet been established causally.

Methods

Two-sample Mendelian randomization (MR) was used to investigate whether gut microbiome had a causal effect on the risk of CVDs. To obtain comprehensive results, we performed two sets of MR analyses, one with single nucleotide polymorphisms (SNPs) that smaller than the genome-wide statistical significance threshold (5 × 10−8) as instrumental variables, and the other with SNPs that lower than the locus-wide significance level (1 × 10−5). Summary-level statistics for CVDs, including coronary artery disease (CAD), myocardial infarction, heart failure, atrial fibrillation, stroke and its subtypes were collected. The ME estimation was performed using the inverse-variance weighted and Wald ratio methods. Sensitivity analysis was performed using the weighted median, MR-Egger, leave-one-out analysis, MR pleiotropy residual sum and outlier and MR Steiger.

Results

Based on the locus-wide significance level, genetically predicted genus Oxalobacter was positively associated with the risk of CAD (odds ratio (OR) = 1.06, 95% confidence interval (CI), 1.03 – 1.10, P = 1.67 × 10−4), family Clostridiaceae_1 was negatively correlated with stroke risk (OR = 0.83,95% CI, 0.75–0.93, P = 7.76 × 10−4) and ischemic stroke risk (OR = 0.823,95% CI, 0.74–0.92, P = 4.15 × 10−4). There was no causal relationship between other genetically predicted gut microbiome components and CVDs risk. Based on the genome-wide statistical significance threshold, the results showed that the gut microbiome had no causal relationship with CVDs risk.

Conclusion

Our findings reveal that there are beneficial or adverse causal effects of gut microbiome components on CVDs risk and provide novel insights into strategies for the prevention and management of CVDs through the gut microbiome.

Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement

This 2022 European Atherosclerosis Society lipoprotein(a) [Lp(a)] consensus statement updates evidence for the role of Lp(a) in atherosclerotic cardiovascular disease (ASCVD) and aortic valve stenosis, provides clinical guidance for testing and treating elevated Lp(a) levels, and considers its inclusion in global risk estimation. Epidemiologic and genetic studies involving hundreds of thousands of individuals strongly support a causal and continuous association between Lp(a) concentration and cardiovascular outcomes in different ethnicities; elevated Lp(a) is a risk factor even at very low levels of low-density lipoprotein cholesterol. High Lp(a) is associated with both microcalcification and macrocalcification of the aortic valve. Current findings do not support Lp(a) as a risk factor for venous thrombotic events and impaired fibrinolysis. Very low Lp(a) levels may associate with increased risk of diabetes mellitus meriting further study. Lp(a) has pro-inflammatory and pro-atherosclerotic properties, which may partly relate to the oxidized phospholipids carried by Lp(a). This panel recommends testing Lp(a) concentration at least once in adults; cascade testing has potential value in familial hypercholesterolaemia, or with family or personal history of (very) high Lp(a) or premature ASCVD. Without specific Lp(a)-lowering therapies, early intensive risk factor management is recommended, targeted according to global cardiovascular risk and Lp(a) level. Lipoprotein apheresis is an option for very high Lp(a) with progressive cardiovascular disease despite optimal management of risk factors. In conclusion, this statement reinforces evidence for Lp(a) as a causal risk factor for cardiovascular outcomes. Trials of specific Lp(a)-lowering treatments are critical to confirm clinical benefit for cardiovascular disease and aortic valve stenosis.

Use of Lipoprotein(a) in clinical practice: A biomarker whose time has come. A scientific statement from the National Lipid Association

Lipoprotein(a) [Lp(a)] is a well-recognized, independent risk factor for atherosclerotic cardiovascular disease, with elevated levels estimated to be prevalent in 20% of the population. Observational and genetic evidence strongly support a causal relationship between high plasma concentrations of Lp(a) and increased risk of atherosclerotic cardiovascular disease-related events, such as myocardial infarction and stroke, and valvular aortic stenosis. In this scientific statement, we review an array of evidence-based considerations for testing of Lp(a) in clinical practice and the utilization of Lp(a) levels to inform treatment strategies in primary and secondary prevention.

Polygenic Risk Scores for Cardiovascular Disease: A Scientific Statement From the American Heart Association

Cardiovascular disease is the leading contributor to years lost due to disability or premature death among adults. Current efforts focus on risk prediction and risk factor mitigation' which have been recognized for the past half-century. However, despite advances, risk prediction remains imprecise with persistently high rates of incident cardiovascular disease. Genetic characterization has been proposed as an approach to enable earlier and potentially tailored prevention. Rare mendelian pathogenic variants predisposing to cardiometabolic conditions have long been known to contribute to disease risk in some families. However, twin and familial aggregation studies imply that diverse cardiovascular conditions are heritable in the general population. Significant technological and methodological advances since the Human Genome Project are facilitating population-based comprehensive genetic profiling at decreasing costs. Genome-wide association studies from such endeavors continue to elucidate causal mechanisms for cardiovascular diseases. Systematic cataloging for cardiovascular risk alleles also enabled the development of polygenic risk scores. Genetic profiling is becoming widespread in large-scale research, including in health care-associated biobanks, randomized controlled trials, and direct-to-consumer profiling in tens of millions of people. Thus, individuals and their physicians are increasingly presented with polygenic risk scores for cardiovascular conditions in clinical encounters. In this scientific statement, we review the contemporary science, clinical considerations, and future challenges for polygenic risk scores for cardiovascular diseases. We selected 5 cardiometabolic diseases (coronary artery disease, hypercholesterolemia, type 2 diabetes, atrial fibrillation, and venous thromboembolic disease) and response to drug therapy and offer provisional guidance to health care professionals, researchers, policymakers, and patients.

Serum lipoprotein(a) and 3-year outcomes in patients undergoing percutaneous coronary intervention

BACKGROUND AND AIMS

We aimed at addressing the association between serum lipoprotein (a) levels and clinical outcomes of consecutive patients undergoing PCI.

METHODS

We used consecutive patients undergoing PCI at the Heart Center University of Freiburg, Bad Krozingen in Germany between January 2005 and November 2013. A total of 6679 patients [men (n = 5391) and women (n = 1288)] mean aged 67.5 (± 11.1) years were assessed at baseline and prospectively followed for 3 years. Lp(a) measurement were performed at hospital admission as a routine laboratory parameter.

RESULTS

Approximately 30% of PCI patients show an elevated Lp(a) value of more than 50mg/dL. In total, 736 Patients died during the follow-up, thereof 189 (11.3%) in the first quartile, 186 (10.7%) in the second quartile, 183 (11.5%) in the third quartile and 178 (10.7%) in the last quartile (p value 0.843 from LogRank test). The MACE rate showed consistent results with 409 (24.4%), 385 (22.1%), 395 (24.7%) and 419 (25.3%) in the different respective quartiles (p value 0.125 from LogRank test).

CONCLUSION

In this large non-selected cohort of patients undergoing PCI followed by moderate intensity statin therapy, higher Lp(a) levels were not associated with worse clinical outcomes during a follow-up of 3 years.

Triglyceride Metabolism Modifies Lipoprotein(a) Plasma Concentration

BACKGROUND

Lipoprotein(a) (Lp(a)) is a significant cardiovascular risk factor. Knowing the mechanisms that regulate its concentration can facilitate the development of Lp(a)-lowering drugs. This study analyzes the relationship between triglycerides (TGs) and Lp(a) concentrations, cross-sectionally and longitudinally, and the influence of the number and composition of TG-rich lipoproteins, and the APOE genotype.

METHODS

Data from Aragon Workers Health Study (AWHS) (n = 5467), National Health and Nutrition Examination Survey III phase 2 (n = 3860), and Hospital Universitario Miguel Servet (HUMS) (n = 2079) were used for cross-sectional TG and Lp(a) relationship. Lp(a) intrasubject variation was studied in AWHS participants and HUMS patients with repeated measurements. TG-rich lipoproteins were quantified by nuclear magnetic resonance in a subsample from AWHS. Apolipoproteins B and E were quantified by Luminex in very low-density lipoprotein (VLDL) isolated by ultracentrifugation, from HUMS samples. APOE genotyping was carried in AWHS and HUMS participants. Regression models adjusted for age and sex were used to study the association.

RESULTS

The 3 studies showed an inverse relationship between TG and Lp(a). Increased VLDL number, size, and TG content were associated with significantly lower Lp(a). There was an inverse association between the apoE concentration in VLDL and Lp(a). No significant association was observed for apolipoprotein (apo)B. Subjects carrying the apoE2/E2 genotype had significantly lower levels of Lp(a).

CONCLUSION

Our results show an inverse relationship Lp(a)-TG. Subjects with larger VLDL size have lower Lp(a), and lower values of Lp(a) were present in patients with apoE-rich VLDL and apoE2/E2 subjects. Our results suggest that bigger VLDLs and VLDLs enriched in apoE are inversely involved in Lp(a) plasma concentration.