Elevated Lp(a): Guidance for Identifying and Managing Patients.

Lipoprotein(a) (Lp(a)) is a unique low-density lipoprotein-like lipoprotein that is considered an independent and causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve stenosis. The Lp(a) molecule also contains apolipoprotein A and apolipoprotein B, which collectively promote atherosclerosis, thrombosis, and inflammation. Lp(a) is highly genetic and minimally responsive to nonpharmacological measures. Lp(a) serum levels ≥125 nmol/L are associated with increased ASCVD risk, but this threshold has not been accepted universally. Elevated Lp(a) is the most common genetic dyslipidemia affecting approximately 20% of the general population. Certain currently available lipid-lowering drugs, including the proprotein convertase subtilisin/kexin type 9 therapies, produce moderate reductions in Lp(a); however, none are indicated for the treatment of elevated Lp(a). There are currently four investigational RNA-based therapeutic agents that reduce Lp(a) by 70% to 100%. Two of these agents are being evaluated for ASCVD risk reduction in adequately powered outcomes trials, with results expected in 2 to 3 years. Until such therapies become available and demonstrate favorable clinical outcomes, strategies for elevated Lp(a) primarily involve early and intensive ASCVD risk factor management.

Apolipoprotein B - An ideal biomarker for atherosclerosis?

This review article describes the pathophysiological mechanisms linking Apolipoprotein B (Apo-B) and atherosclerosis, summarizes the existing evidence on Apo B as a predictor of atherosclerotic cardiovascular disease and recommendations of (inter)national treatment guidelines regarding Apo B in dyslipidemia management. A single Apo B molecule is present in every particle of very low-density lipoprotein, intermediate density lipoprotein, low density lipoprotein, and lipoprotein(a). This unique single Apo B per particle ratio makes plasma Apo B concentration a direct measure of the number of circulating atherogenic lipoproteins. This review of global evidence on Apo B as a biomarker for atherosclerosis confirms that Apo B is a single atherogenic lipid marker present in all lipids sub-fractions except HDL-C, and thus, Apo B integrates and extends the information from triglycerides and cholesterol, which could simplify and improve care for atherosclerotic cardiovascular disease.

Lipoprotein(a) and Long-Term Cardiovascular Risk in a Multi-Ethnic Pooled Prospective Cohort.

BACKGROUND: Lipoprotein(a) (Lp[a]) is a causal genetic risk factor for atherosclerotic cardiovascular disease (ASCVD). There are limited long-term follow-up data from large U.S. population cohorts. OBJECTIVES: This study examined the relationship of Lp(a) with ASCVD outcomes in a large, pooled, multi-ethnic U.S. METHODS: The study included data on Lp(a) and ASCVD outcomes from 5 U.S. PROSPECTIVE STUDIES: MESA (Multi-Ethnic Study of Atherosclerosis), CARDIA (Coronary Artery Risk Development in Young Adults), JHS (Jackson Heart Study), FHS-OS (Framingham Heart Study-Offspring), and ARIC (Atherosclerosis Risk In Communities). Lp(a) levels were classified on the basis of cohort-specific percentiles. Multivariable Cox regression related Lp(a) with composite incident ASCVD events by risk group and diabetes status. RESULTS: The study included 27,756 persons without previous ASCVD who were aged 20 to 79 years, including 55.0% women, 35.6% Black participants, and 7.6% patients with diabetes, with mean follow-up of 21.1 years. Compared with Lp(a) levels <50th percentile, Lp(a) levels in the 50th to <75th, 75th to <90th, and ≥90th percentiles had adjusted HRs of 1.06 (95% CI: 0.99-1.14), 1.18 (95% CI: 1.09-1.28), and 1.46 (95% CI: 1.33-1.59), respectively for ASCVD events. Elevated Lp(a) predicted incident ASCVD events similarly by risk group, sex, and race or ethnic groups, but more strongly in patients with vs without diabetes (interaction P = 0.0056), with HRs for Lp(a) levels ≥90th percentile of 1.92 (95% CI: 1.50-2.45) and 1.41 (95% CI: 1.28-1.55), respectively. Lp(a) also individually predicted myocardial infarction, revascularization, stroke, and coronary heart disease death, but not total mortality. CONCLUSIONS: The study shows, in a large U.S. pooled cohort, that higher Lp(a) levels are associated with an increased ASCVD risk, including in patients with diabetes.

Lipoprotein(a) as a blood marker for large artery atherosclerosis stroke etiology: validation in a prospective cohort from a swiss stroke center.

BACKGROUND: Lipoprotein (a) [Lp(a)] serum levels are highly genetically determined and promote atherogenesis. High Lp(a) levels are associated with increased cardiovascular morbidity. Serum Lp(a) levels have recently been associated with large artery atherosclerosis (LAA) stroke. We aimed to externally validate this association in an independent cohort. METHODS: This study stems from the prospective multicentre CoRisk study (CoPeptin for Risk Stratification in Acute Stroke patients [NCT00878813]), conducted at the University Hospital Bern, Switzerland, between 2009 and 2011, in which Lp(a) plasma levels were measured within the first 24 hours after stroke onset. We assessed the association of Lp(a) with LAA stroke using multivariable logistic regression and performed interaction analyses to identify potential effect modifiers. RESULTS: Of 743 patients with ischaemic stroke, 105 (14%) had LAA stroke aetiology. Lp(a) levels were higher for LAA stroke than non-LAA stroke patients (23.0 nmol/l vs 16.3 nmol/l, p = 0.01). Multivariable regression revealed an independent association of log10and#xA0;Lp(a) with LAA stroke aetiology (aOR 1.47 [95% CI 1.03and#x2013;2.09], p = 0.03). The interaction analyses showed that Lp(a) was not associated with LAA stroke aetiology among patients with diabetes. CONCLUSIONS: In a well-characterised cohort of patients with ischaemic stroke, we validated the association of higher Lp(a) levels with LAA stroke aetiology, independent of traditional cardiovascular risk factors. These findings may inform randomised clinical trials investigating the effect of Lp(a) lowering agents on cardiovascular outcomes. The CoRisk (CoPeptin for Risk Stratification in Acute Patients) study is registered on ClinicalTrials.gov. REGISTRATION NUMBER: NCT00878813.

Polygenic scores for cardiovascular risk factors improve estimation of clinical outcomes in CCB treatment compared to pharmacogenetic variants alone.

Pharmacogenetic variants are associated with clinical outcomes during Calcium Channel Blocker (CCB) treatment, yet whether the effects are modified by genetically predicted clinical risk factors is unknown. We analyzed 32,000 UK Biobank participants treated with dihydropiridine CCBs (mean 5.9 years), including 23 pharmacogenetic variants, and calculated polygenic scores for systolic and diastolic blood pressures, body fat mass, and other patient characteristics. Outcomes included treatment discontinuation and heart failure. Pharmacogenetic variant rs10898815-A (NUMA1) increased discontinuation rates, highest in those with high polygenic scores for fat mass. The RYR3 variant rs877087 T-allele alone modestly increased heart failure risks versus non-carriers (HR:1.13, p = 0.02); in patients with high polygenic scores for fat mass, lean mass, and lipoprotein A, risks were substantially elevated (HR:1.55, p = 4 × 10-5). Incorporating polygenic scores for adiposity and lipoprotein A may improve risk estimates of key clinical outcomes in CCB treatment such as treatment discontinuation and heart failure, compared to pharmacogenetic variants alone.

[DIAGNOSIS AND TREATMENT OF ELEVATED LIPOPROTEIN(A) IN ISRAEL: CONSENSUS STATEMENT FROM THE ISRAEL SOCIETY FOR RESEARCH, PREVENTION AND TREATMENT OF ATHEROSCLEROSIS AND ISRAEL SOCIETY FOR CLINICAL LABORATORY SCIENCES].

INTRODUCTION: Lipoprotein(a) [Lp(a)] is composed of 2 major protein components, a low-density lipoprotein (LDL) cholesterol-like particle containing apolipoprotein B (apo B) that is covalently bound to apolipoprotein(a). Its level is predominantly genetically determined, and it is estimated that 20% to 25% of the population have Lp(a) levels that are associated with increased cardiovascular risk. Elevated Lp(a) is related to increased vascular inflammation, calcification, atherogenesis and thrombosis, and is considered an independent and potentially causal risk factor for atherosclerotic cardiovascular diseases and calcified aortic valve stenosis. Recent data demonstrate that Lp(a) testing has the potential to reclassify patients' risk and improve cardiovascular risk prediction, and therefore could inform clinical decision-making regarding risk management. Statins and ezetimibe are ineffective in lowering Lp(a) levels, whereas proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have a modest effect on Lp(a) reduction. Nevertheless, RNA interference-based therapies with potent Lp(a)-lowering effects are in advanced stages of development, and clinical trials are underway to confirm their benefit in reducing cardiovascular events. This scientific consensus document was developed by a committee that consisted of representatives from the Israeli Society for the Research, Prevention and Treatment of Atherosclerosis, and the Israeli Society for Clinical Laboratory Sciences, in order to create uniformity in Lp(a) measurement methods, indications for testing and reporting of the results, aiming to improve the diagnosis and management of elevated Lp(a) in clinical practice.

Lipoprotein(a) and Atherosclerotic Cardiovascular Disease: Where Do We Stand?

Lipoprotein(a) [Lp(a)] consists of a low-density lipoprotein-like molecule and an apolipoprotein(a) [apo(a)] particle. Lp(a) has been suggested to be an independent risk factor of atherosclerotic cardiovascular disease (ASCVD). Lp(a) plasma levels are considered to be 70-90% genetically determined through the codominant expression of the LPA gene. Therefore, Lp(a) levels are almost stable during an individual's lifetime. This lifelong stability, together with the difficulties in measuring Lp(a) levels in a standardized manner, may account for the scarcity of available drugs targeting Lp(a). In this review, we synopsize the latest data regarding the structure, metabolism, and factors affecting circulating levels of Lp(a), as well as the laboratory determination measurement of Lp(a), its role in the pathogenesis of ASCVD and thrombosis, and the potential use of various therapeutic agents targeting Lp(a). In particular, we discuss novel agents, such as antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs) that are currently being developed and target Lp(a). The promising role of muvalaplin, an oral inhibitor of Lp(a) formation, is then further analyzed.

Association between Serum Phytosterols and Lipid Levels in a Population-Based Study.

The association between phytosterols and lipid levels remains poorly assessed at a population level. We assessed the associations between serum levels of six phytosterols (campesterol, campestanol, stigmasterol, sitosterol, sitostanol and brassicasterol) and of lipids [total, low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol, triglycerides, apolipopoprotein A-IV and lipoprotein Lp(a)] in two cross-sectional surveys of a population-based, prospective study. Data from 910 participants (59.1% women, 70.4 ± 4.7 years) for the first survey (2009-2012) and from 721 participants (60.2% women, 75.1 ± 4.7 years) for the second survey (2014-2017) were used. After multivariable adjustment, all phytosterols were positively associated with total cholesterol: slope and (95% confidence interval) 1.594 (1.273-1.915); 0.073 (0.058-0.088); 0.060 (0.044-0.076); 2.333 (1.836-2.830); 0.049 (0.033-0.064) and 0.022 (0.017-0.028) for campesterol, campestanol, stigmasterol, sitosterol, sitostanol and brassicasterol, respectively, in the first survey, and 1.257 (0.965-1.548); 0.066 (0.052-0.079); 0.049 (0.034-0.063); 1.834 (1.382-2.285); 0.043 (0.029-0.057) and 0.018 (0.012-0.023) in the second survey, all p < 0.05. Similar positive associations were found between all phytosterols and LDL cholesterol. Positive associations were found between campesterol and sitosterol and HDL-cholesterol: slope and (95% CI) 0.269 (0.134-0.405) and 0.393 (0.184-0.602) for campesterol and sitosterol, respectively, in the first survey, and 1.301 (0.999-1.604) and 0.588 (0.327-0.849) in the second survey, all p < 0.05. No associations were found between phytosterols and triglyceride or lipoprotein Lp(a) levels, while a positive association between campesterol and apolipoprotein A-IV levels was found: 2.138 (0.454-3.822). Upon normal dietary intakes, serum phytosterol levels were positively associated with total and LDL cholesterol levels, while no consistent association with other lipid markers was found.

Digital droplet PCR versus quantitative PCR for lipoprotein (a) kringle IV type 2 repeat polymorphism genetic characterization.

BACKGROUND: Lipoprotein(a) [Lp(a)] level variability, related to atherothrombotic risk increase, is mainly attributed to LPA gene, encoding apolipoprotein(a), with kringle IV type 2 (KIV2) copy number variation (CNV) acting as the primary genetic determinant. Genetic characterization of Lp(a) is in continuous growth; nevertheless, the peculiar structural characteristics of this variant constitute a significant challenge to the development of effective detection methods. The aim of the study was to compare quantitative real-time PCR (qPCR) and digital droplet PCR (ddPCR) in the evaluation of KIV2 repeat polymorphism. METHODS: We analysed 100 subjects tested for cardiovascular risk in which Lp(a) plasma levels were assessed. RESULTS: Correlation analysis between CNV values obtained with the two methods was slightly significant (R = 0.413, p = 0.00002), because of the wider data dispersion in qPCR compared with ddPCR. Internal controls C1, C2 and C3 measurements throughout different experimental sessions revealed the superior stability of ddPCR, which was supported by a reduced intra/inter-assay coefficient of variation determined in this method compared to qPCR. A significant inverse correlation between Lp(a) levels and CNV values was confirmed for both techniques, but it was higher when evaluated by ddPCR than qPCR (R = -0.393, p = 0.000053 vs R = -0.220, p = 0.028, respectively). When dividing subjects into two groups according to 500 mg/L Lp(a) cut-off value, a significantly lower number of KIV2 repeats emerged among subjects with greater Lp(a) levels, with stronger evidence in ddPCR than in qPCR (p = 0.000013 and p = 0.001, respectively). CONCLUSIONS: Data obtained support a better performance of ddPCR in the evaluation of KIV2 repeat polymorphism.

Apolipoprotein(a) production and clearance are associated with plasma IL-6 and IL-18 levels, dependent on ethnicity.

BACKGROUND AND AIMS: High plasma lipoprotein (a) [Lp(a)] levels are associated with increased atherosclerotic cardiovascular disease (ASCVD), in part attributed to elevated inflammation. High plasma Lp(a) levels inversely correlate with apolipoprotein (a) [(APO(a)] isoform size. APO(a) isoform size is negatively associated with APO(a) production rate (PR) and positively associated with APO(a) fractional catabolic rate (FCR). We asked whether APO(a) PR and FCR (kinetics) are associated with plasma levels of interleukin (IL)-6 and IL-18, pro-inflammatory interleukins that promote ASCVD. METHODS: We used samples from existing data of APO(a) kinetic studies from an ethnically diverse cohort (n = 25: 10 Black, 9 Hispanic, and 6 White subjects) and assessed IL-6 and IL-18 plasma levels. We performed multivariate linear regression analyses to examine the relationships between predictors APO(a) PR or APO(a) FCR, and outcome variables IL-6 or IL-18. In these analyses, we adjusted for parameters known to affect Lp(a) levels and APO(a) PR and FCR, including race/ethnicity and APO(a) isoform size. RESULTS: APO(a) PR and FCR were positively associated with plasma IL-6, independent of isoform size, and dependent on race/ethnicity. APO(a) PR was positively associated with plasma IL-18, independent of isoform size and race/ethnicity. APO(a) FCR was not associated with plasma IL-18. CONCLUSIONS: Our studies demonstrate a relationship between APO(a) PR and FCR and plasma IL-6 or IL-18, interleukins that promote ASCVD. These studies provide new insights into Lp(a) pro-inflammatory properties and are especially relevant in view of therapies targeting APO(a) to decrease cardiovascular risk.

Lipoprotein(a) Blood Levels and Cardiovascular Risk Reduction With Icosapent Ethyl.

BACKGROUND: Elevated lipoprotein(a) (Lp[a]) concentrations are associated with increased cardiovascular event risk even in the presence of well-controlled low-density lipoprotein cholesterol levels, but few treatments are documented to reduce this residual risk. OBJECTIVES: The aim of this post hoc analysis of REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial) was to explore the cardiovascular benefit of icosapent ethyl (IPE) across a range of Lp(a) levels. METHODS: A total of 8,179 participants receiving statin therapy with established cardiovascular disease or age ≥50 years with diabetes and ≥1 additional risk factor, fasting triglyceride 1.69 to 5.63 mmol/L, and low-density lipoprotein cholesterol 1.06 to 2.59 mmol/L were randomized to receive 2 g twice daily of IPE or matching placebo. Relationships between continuous baseline Lp(a) mass concentration and risk for first and total (first and subsequent) major adverse cardiovascular events (MACE) were analyzed, along with the effects of IPE on first MACE among those with Lp(a) concentrations ≥50 or <50 mg/dL. RESULTS: Among 7,026 participants (86% of those randomized) with baseline Lp(a) assessments, the median concentration was 11.6 mg/dL (Q1-Q3: 5.0-37.4 mg/dL). Lp(a) had significant relationships with first and total MACE (P < 0.0001), while event reductions with IPE did not vary across the range of Lp(a) (interaction P > 0.10). IPE significantly reduced first MACE in subgroups with concentrations ≥50 and <50 mg/dL. CONCLUSIONS: Baseline Lp(a) concentration was prognostic for MACE among participants with elevated triglyceride levels receiving statin therapy. Importantly, IPE consistently reduced MACE across a range of Lp(a) levels, including among those with clinically relevant elevations.

Lipoprotein(a), C-Reactive Protein, and Cardiovascular Risk in Primary and Secondary Prevention Populations.

Importance: Elevated lipoprotein(a) (Lp[a]) is a putative causal risk factor for atherosclerotic cardiovascular disease (ASCVD). There are conflicting data as to whether Lp(a) may increase cardiovascular risk only in the presence of concomitant inflammation. Objective: To investigate whether Lp(a) is associated with cardiovascular risk independent of high-sensitivity C-reactive protein (hs-CRP) in both primary and secondary prevention populations. Design, Setting, and Participants: This cohort study uses data from 3 distinct cohorts, 1 population-based cohort and 2 randomized clinical trials. Participants included individuals from the UK Biobank (data from 2006-2010) without prevalent ASCVD, participants in the FOURIER (TIMI 59) trial (data from 2013-2017) who had baseline Lp(a) and hs-CRP data, and participants in the SAVOR-TIMI 53 trial (data from 2010-2013) who had prevalent ASCVD and baseline values for Lp(a) and hs-CRP. The data analysis took place from November 2022 to November 2023. Exposure: Baseline plasma Lp(a), considered either as a continuous variable or dichotomized at 125 nmol/L. Main Outcomes and Measures: Risk of major adverse cardiovascular events (MACE) (composite of cardiovascular death, myocardial infarction [MI], or ischemic stroke), the individual MACE components, and peripheral artery disease (PAD). Results: Among 357 220 individuals in the UK Biobank without prevalent ASCVD, 232 699 (65%) had low hs-CRP (<2 mg/L), and 124 521 (35%) had high hs-CRP (≥2 mg/L) values. In a Cox proportional hazard model adjusted for ASCVD risk factors, higher Lp(a) was associated with increased cardiovascular risk regardless of baseline hs-CRP value for MACE (hs-CRP ≥2 mg/L: hazard ratio [HR] per 50-nmol/L higher Lp[a], 1.05; 95% CI, 1.04-1.07; P < .001; for hs-CRP <2 mg/L: HR, 1.05; 95% CI, 1.04-1.07; P < .001; P = .80 for interaction), as well as MI, ischemic stroke, and PAD individually. Among 34 020 individuals in the FOURIER and SAVOR trials with baseline cardiometabolic disease, there were 17 643 (52%) with low and 16 377 (48%) with high baseline hs-CRP values. In Cox proportional hazard models using aggregated data from FOURIER and SAVOR, higher baseline Lp(a) was associated with increased cardiovascular risk regardless of baseline hs-CRP for MACE (hs-CRP ≥2 mg/L: HR per 50-nmol/L higher Lp[a], 1.02; 95% CI, 1.00-1.05; P = .04; hs-CRP <2 mg/L: HR, 1.05; 95% CI, 1.02-1.08; P < .001; P = .16 for interaction), MI, and PAD. Conclusions and Relevance: In this study, higher levels of Lp(a) were associated with MACE, MI, and PAD in both primary and secondary prevention populations regardless of baseline hs-CRP value.

The association of lipoprotein(a) and coronary artery calcium in asymptomatic patients: a systematic review and meta-analysis.

AIMS: Lipoprotein(a) [Lp(a)] is an atherogenic lipid particle associated with increased risk for coronary heart disease (CHD) events. Coronary artery calcium (CAC) score is a tool to diagnose subclinical atherosclerosis and guide clinical decision-making for primary prevention of CHD. Studies show conflicting results concerning the relationship between Lp(a) and CAC in asymptomatic populations. We conducted a meta-analysis to evaluate the association of Lp(a) and CAC in asymptomatic patients. METHODS AND RESULTS: We systematically searched PubMed, Embase, and Cochrane until April 2023 for studies evaluating the association between Lp(a) and CAC in asymptomatic patients. We evaluated CAC > 0 Agatston units, and CAC ≥ 100. Lp(a) was analysed as a continuous or dichotomous variable. We assessed the association between Lp(a) and CAC with pooled odds ratios (OR) adopting a random-effects model. A total of 23 105 patients from 18 studies were included in the meta-analysis with a mean age of 55.9 years, 46.4% female. Elevated Lp(a) increased the odds of CAC > 0 [OR 1.31; 95% confidence intervals (CI) 1.05-1.64; P = 0.02], CAC ≥100 (OR 1.29; 95% CI 1.01-1.65; P = 0.04; ), and CAC progression (OR 1.43; 95% CI 1.20-1.70; P < 0.01; ). For each increment of 1 mg/dL in Lp(a) there was a 1% in the odds of CAC > 0 (OR 1.01; 95% CI 1.01-1.01; P < 0.01). CONCLUSION: Our findings of this meta-analysis suggest that Lp(a) is positively associated with a higher likelihood of CAC. Higher Lp(a) levels increased the odds of CAC >0. These data support the concept that Lp(a) is atherogenic, although with high heterogeneity and a low level of certainty. PROTOCOL REGISTRATION: CRD42023422034. KEY FINDINGS: Asymptomatic patients with elevated Lp(a) had 31% higher chances of having any coronary calcification (CAC > 0) and 29% higher chances of having more advanced calcification (CAC > 100). It increased the chances of having progression of coronary calcification over time by 43%. For each 1 mg/dL of Lp(a) there was an increment of 1% chance of having coronary calcification.

We conducted a meta-analysis to evaluate the association between Lp(a) and coronary calcification in asymptomatic patients without a known history of coronary artery disease.